Noradrenergic modulation of neural erotic stimulus perception.

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Graf, Heiko; Wiegers, Maike; Metzger, Coraline Danielle; Walter, Martin; Grön, Georg; Abler, Birgit

2017-09-01

We recently investigated neuromodulatory effects of the noradrenergic agent reboxetine and the dopamine receptor affine amisulpride in healthy subjects on dynamic erotic stimulus processing. Whereas amisulpride left sexual functions and neural activations unimpaired, we observed detrimental activations under reboxetine within the caudate nucleus corresponding to motivational components of sexual behavior. However, broadly impaired subjective sexual functioning under reboxetine suggested effects on further neural components. We now investigated the same sample under these two agents with static erotic picture stimulation as alternative stimulus presentation mode to potentially observe further neural treatment effects of reboxetine. 19 healthy males were investigated under reboxetine, amisulpride and placebo for 7 days each within a double-blind cross-over design. During fMRI static erotic picture were presented with preceding anticipation periods. Subjective sexual functions were assessed by a self-reported questionnaire. Neural activations were attenuated within the caudate nucleus, putamen, ventral striatum, the pregenual and anterior midcingulate cortex and in the orbitofrontal cortex under reboxetine. Subjective diminished sexual arousal under reboxetine was correlated with attenuated neural reactivity within the posterior insula. Again, amisulpride left neural activations along with subjective sexual functioning unimpaired. Neither reboxetine nor amisulpride altered differential neural activations during anticipation of erotic stimuli. Our results verified detrimental effects of noradrenergic agents on neural motivational but also emotional and autonomic components of sexual behavior. Considering the overlap of neural network alterations with those evoked by serotonergic agents, our results suggest similar neuromodulatory effects of serotonergic and noradrenergic agents on common neural pathways relevant for sexual behavior. Copyright © 2017 Elsevier B.V. and

Selective deficiencies in descending inhibitory modulation in neuropathic rats: implications for enhancing noradrenergic tone.

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Patel, Ryan; Qu, Chaoling; Xie, Jennifer Y; Porreca, Frank; Dickenson, Anthony H

2018-05-31

Pontine noradrenergic neurones form part of a descending inhibitory system that influences spinal nociceptive processing. Weak or absent descending inhibition is a common feature of chronic pain patients. We examined the extent to which the descending noradrenergic system is tonically active, how control of spinal neuronal excitability is integrated into thalamic relays within sensory-discriminative projection pathways, and how this inhibitory control is altered after nerve injury. In vivo electrophysiology was performed in anaesthetised spinal nerve ligated (SNL) and sham-operated rats to record from wide dynamic range neurones in the ventral posterolateral thalamus (VPL). In sham rats, spinal block of α2-adrenoceptors with atipamezole resulted in enhanced stimulus-evoked and spontaneous firing in the VPL, and produced conditioned place avoidance. However, in SNL rats these conditioned avoidance behaviours were absent. Furthermore, inhibitory control of evoked neuronal responses was lost but spinal atipamezole markedly increased spontaneous firing. Augmenting spinal noradrenergic tone in neuropathic rats with reboxetine, a selective noradrenergic reuptake inhibitor, modestly reinstated inhibitory control of evoked responses in the VPL but had no effect on spontaneous firing. In contrast, clonidine, an α2 agonist, inhibited both evoked and spontaneous firing, and exhibited increased potency in SNL rats compared to sham controls. These data suggest descending noradrenergic inhibitory pathways are tonically active in sham rats. Moreover, in neuropathic states descending inhibitory control is diminished, but not completely absent, and distinguishes between spontaneous and evoked neuronal activity. These observations may have implications for how analgesics targeting the noradrenergic system provide relief.

Characterization of the binding of 3H-norzimeldine, a 5-HT uptake inhibitor, to rat brain homogenates

International Nuclear Information System (INIS)

Hall, H.

1984-01-01

The binding of radiolabelled norzimeldine, a potent selective 5-HT reuptake inhibitor, to rat brain homogenates is described. 3 H-Norzimeldine binds to a site with high affinity (Ksub(D) = 10.5 nM) in a saturable manner (Bsub(max) = 15.4 pmol/g wet weight in the cerebral cortex). The number of binding sites in the various regions of the brain parallels the capacity of the 5-HT reuptake mechanism. Drugs that inhibit the reuptake of 5-HT are also potent inhibitors of the 3 H-norzimeldine binding, as are the tricyclic antidepressants, which are non-specific inhibitors of the noradrenaline and the 5-HT reuptake. Lesioning experiments using DSP4 (a NA neurotoxin) and p-chloroamphetamine (a 5-HT neurotoxin) suggest that the binding site is located on the presynaptic 5-HT nerve terminal, although a small component of the binding may be to noradrenergic uptake sites as well.(author)

Complementary neural correlates of motivation in dopaminergic and noradrenergic neurons of monkeys.

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Sebastien eBouret

2012-07-01

Full Text Available Rewards have many influences on learning, decision-making and performance. All seem to rely on complementary actions of two closely related catecholaminergic neuromodulators, dopamine and noradrenaline. We compared single unit activity of dopaminergic neurons of the substantia nigra pars compacta and noradrenergic neurons of the locus coeruleus in monkeys performing a reward schedule task. Their motivation, indexed using operant performance, increased as they progressed through schedules ending in reward delivery. The responses of dopaminergic and noradrenergic neurons around the time of major task events, visual cues predicting trial outcome and operant action to complete a trial, were similar, in that they occurred at the same time. They were also similar in that they both responded most strongly to the first cues in schedules, which are the most informative cues. The neuronal responses around the time of the monkeys’ actions were different, in that the response intensity profiles changed in opposite directions. Dopaminergic responses were stronger around predictably rewarded correct actions whereas noradrenergic responses were greater around predictably unrewarded correct actions. The complementary response profiles related to the monkeys operant actions suggest that dopamine neurons might relate to the value of the current action whereas the noradrenergic neurons relate to the psychological cost of that action.

Characterization of the binding of /sup 3/H-norzimeldine, a 5-HT uptake inhibitor, to rat brain homogenates

Energy Technology Data Exchange (ETDEWEB)

Hall, H. (Department of Biochemical Neuropharmacology, Research and Development Laboratories, Astra Laekemedel, Soedertaelje, Sweden)

1984-01-01

The binding of radiolabelled norzimeldine, a potent selective 5-HT reuptake inhibitor, to rat brain homogenates is described. /sup 3/H-Norzimeldine binds to a site with high affinity (Ksub(D) = 10.5 nM) in a saturable manner (Bsub(max) = 15.4 pmol/g wet weight in the cerebral cortex). The number of binding sites in the various regions of the brain parallels the capacity of the 5-HT reuptake mechanism. Drugs that inhibit the reuptake of 5-HT are also potent inhibitors of the /sup 3/H-norzimeldine binding, as are the tricyclic antidepressants, which are non-specific inhibitors of the noradrenaline and the 5-HT reuptake. Lesioning experiments using DSP4 (a NA neurotoxin) and p-chloroamphetamine (a 5-HT neurotoxin) suggest that the binding site is located on the presynaptic 5-HT nerve terminal, although a small component of the binding may be to noradrenergic uptake sites as well.

Noradrenergic activation of the basolateral amygdala modulates the consolidation of object-in-context recognition memory

NARCIS (Netherlands)

Barsegyan, Areg; McGaugh, James L.; Roozendaal, Benno

2014-01-01

Noradrenergic activation of the basolateral complex of the amygdala (BLA) is well known to enhance the consolidation of long-term memory of highly emotionally arousing training experiences. The present study investigated whether such noradrenergic activation of the BLA also influences the

Evidence for a role of corticopetal, noradrenergic systems in the development of executive function.

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Mokler, David J; Miller, Christine E; McGaughy, Jill A

2017-09-01

Adolescence is a period during which many aspects of executive function are maturing. Much of the literature has focused on discrepancies between sub-cortical and cortical development that is hypothesized to lead to over-processing of reinforcement related stimuli unchecked by fully matured response inhibition. Specifically, maturation of sub-cortical dopaminergic systems that terminate in the nucleus accumbens has been suggested to occur prior to the full maturation of corticopetal dopaminergic systems. However, converging evidence supports the hypothesis that many aspects of cognitive control are critically linked to cortical noradrenergic systems, that the effectiveness of drugs used to treat disorders of executive function, e.g. ADHD, may result primarily from increases in cortical norepinephrine (NE) and that cortical noradrenergic systems mature across adolescence. However, little attention has been given to the development of this system during adolescence or to its influence in executive function. In the present paper, we discuss the developmental trajectory of the noradrenergic system of the forebrain, highlight the interactions between noradrenergic and dopaminergic systems, and highlight the contribution of the immature corticopetal noradrenergic systems in the ontogeny of several aspects of executive function. Finally we compare data from adolescent rats to those gathered after selective depletion of NE in sub-regions of the prefrontal cortex with an emphasis on the similarities in performance of NE lesioned rats and adolescents. Copyright © 2017 Elsevier Inc. All rights reserved.

Noradrenergic enhancement of associative fear memory in humans

NARCIS (Netherlands)

Soeter, M.; Kindt, M.

2011-01-01

Ample evidence in animals and humans supports the noradrenergic modulation in the formation of emotional memory. However, in humans the effects of stress on emotional memory are traditionally investigated by declarative memory tests (e.g., recall, recognition) for non-associative emotional stimuli

Enhanced down regulation of cortical ±-propranolol sensitive [3H]-DHA binding sites by co-administration of DMI and 5-HT1A partial agonist gepirone

International Nuclear Information System (INIS)

Geissler, M.A.; Yocca, F.D.

1990-01-01

The putative interrelationship between the noradrenergic and serotonergic systems has been supported by numerous studies. Recently, Dudley et al. (1989) demonstrated significant down regulation of cortical β-adrenergic receptors by co-administration of desipramine (DMI), a norepinephrine uptake inhibitor, and the full 5-HT 1A agonist 8-OH-DPAT. To this end, the effects of acute and chronic (4 and 14 day) administration of DMI, gepirone, a selective 5-HT 1A post-synaptic partial agonist, as well as a combination of the two, on cortical (±)-propranolol sensitive [ 3 H]-DHA binding sites were examined in rats. Down regulation was apparent after 4 and 14 day treatment with DMI. However, this was not the case with gepirone. Of particular importance is the demonstration of a greater magnitude of down regulation with co-administration of a greater magnitude of down regulation with co-administration of DMI and gepirone. These results suggests that alteration in rat cortical (±)-propranolol sensitive [ 3 H]-DHA binding sites by noradrenergic uptake inhibitors can be further modulated by selective partial agonist activity at central 5-HT 1A postsynaptic receptors. Further data on the co-administration of DMI and BMY 7378 (7,9-dioxo-8-[2-(4-o-methoxyphenylpiperazinyl)ethyl]-8-azaspiro[4,5]decane dihydrochloride), a weak partial agonist at postsynaptic 5-HT 1A receptors, are also presented

Noradrenergic Stimulation Impairs Memory Generalization in Women.

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Kluen, Lisa Marieke; Agorastos, Agorastos; Wiedemann, Klaus; Schwabe, Lars

2017-07-01

Memory generalization is essential for adaptive decision-making and action. Our ability to generalize across past experiences relies on medial-temporal lobe structures, known to be highly sensitive to stress. Recent evidence suggests that stressful events may indeed interfere with memory generalization. Yet, the mechanisms involved in this generalization impairment are unknown. We tested here whether a pharmacological elevation of major stress mediators-noradrenaline and glucocorticoids-is sufficient to disrupt memory generalization. In a double-blind, placebo-controlled design, healthy men and women received orally a placebo, hydrocortisone, the α2-adrenoceptor antagonist yohimbine that leads to increased noradrenergic stimulation, or both drugs, before they completed an associative learning task probing memory generalization. Drugs left learning performance intact. Yohimbine, however, led to a striking generalization impairment in women, but not in men. Hydrocortisone, in turn, had no effect on memory generalization, neither in men nor in women. The present findings indicate that increased noradrenergic activity, but not cortisol, is sufficient to disrupt memory generalization in a sex-specific manner, with relevant implications for stress-related mental disorders characterized by generalization deficits.

Beta 1- and beta 2-adrenergic 125I-pindolol binding sites in the interpeduncular nucleus of the rat: Normal distribution and the effects of deafferentation

International Nuclear Information System (INIS)

Battisti, W.P.; Artymyshyn, R.P.; Murray, M.

1989-01-01

The plasticity of the beta 1- and beta 2-adrenergic receptor subtypes was examined in the interpeduncular nucleus (IPN) of the adult rat. The beta-adrenergic receptor antagonist 125I-pindolol (125I-PIN) was used in conjunction with the selective subtype antagonists ICI 118,551 and ICI 89,406 to determine the subnuclear distribution of beta 1- and beta 2-adrenergic receptors in this nucleus and to correlate the receptor distribution with the distribution of both noradrenergic afferents from the locus coeruleus (LC) and non-noradrenergic afferents from the fasiculus retroflexus (FR). The density of these binding sites was examined following lesions that decreased (LC lesions) or increased (FR lesions) the density of the noradrenergic projection in the IPN. Quantitative radioautography indicated that beta 1-labeled binding sites account for the larger percentage of binding sites in the IPN. The beta 1-binding sites are densest in those subnuclei that receive a noradrenergic projection from the LC: the central, rostral, and intermediate subnuclei. beta 1-binding sites are algo homogeneously distributed throughout the lateral subnuclei, where there is no detectable noradrenergic innervation. beta 2-binding sites have a more restricted distribution. They are concentrated in the ventral half of the lateral subnuclei, where they account for 70% of total 125I-PIN binding sites. beta 2-binding sites are also present along the ventral border of the IPN. Some of this labeling extends into the central and intermediate subnuclei. Bilateral lesions of the LC, which selectively remove noradrenergic innervation to the IPN, result in an increase in the beta 1-binding sites. Bilateral lesions of the FR, which remove the major cholinergic and peptidergic input from the IPN, elicit an increase in noradrenergic projections and a decrease in beta 1-binding sites

The noradrenergic paradox: implications in the management of depression and anxiety

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Montoya A

2016-03-01

Full Text Available Alonso Montoya,1 Robert Bruins,1 Martin A Katzman,2 Pierre Blier3 1Eli Lilly Canada Inc, 2START Clinic for the Mood and Anxiety Disorders, Toronto, 3Mood Disorders Research Unit, Institute of Mental Health Research, University of Ottawa, Ottawa, ON, Canada Abstract: Both major depressive disorder and the anxiety disorders are major causes of ­disability and markedly contribute to a significant global burden of the disease worldwide. In part because of the significant socioeconomic burden associated with these disorders, theories have been developed to specifically build clinical treatment approaches. One such theory, the monoaminergic hypothesis, has led to the development of several generations of selective and nonselective inhibitors of transporters of serotonin and norepinephrine, with the goal of augmenting monoaminergic transmission. These efforts have led to considerable success in the development of antidepressant therapeutics. However, there is a strong correlation between enhanced noradrenergic activity and fear and anxiety. Consequently, some physicians have expressed concerns that the same enhanced noradrenergic activity that alleviates depression could also promote anxiety. The fact that the serotonergic and noradrenergic reuptake inhibitors are successfully used in the treatment of anxiety and panic disorders seems paradoxical. This review was undertaken to determine if any clinical evidence exists to show that serotonergic and noradrenergic reuptake inhibitors can cause anxiety. The PubMed, EMBASE, and Cochrane Library databases were searched, and the results limited to randomized, double-blind, placebo-controlled studies performed in nongeriatric adults and with clear outcome measures were reported. Based on these criteria, a total of 52 studies were examined. Patients in these studies suffered from depression or anxiety disorders (generalized and social anxiety disorders, panic disorder, and posttraumatic stress disorder. The

Selective inhibition of dopamine-beta-hydroxylase enhances dopamine release from noradrenergic terminals in the medial prefrontal cortex.

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Devoto, Paola; Flore, Giovanna; Saba, Pierluigi; Frau, Roberto; Gessa, Gian L

2015-10-01

results indicate that nepicastat enhances DA release from noradrenergic terminals supposedly by removing NA from α2-autoreceptors. In addition to the inhibition of DA uptake, the latter mechanism may explain the synergistic effect of cocaine on nepicastat-induced DA release.

Autoradiographic localization of 3H-paroxetine-labeled serotonin uptake sites in rat brain

International Nuclear Information System (INIS)

De Souza, E.B.; Kuyatt, B.L.

1987-01-01

Paroxetine is a potent and selective inhibitor of serotonin uptake into neurons. Serotonin uptake sites have been identified, localized, and quantified in rat brain by autoradiography with 3H-paroxetine; 3H-paroxetine binding in slide-mounted sections of rat forebrain was of high affinity (KD = 10 pM) and the inhibition affinity constant (Ki) values of various drugs in competing 3H-paroxetine binding significantly correlated with their reported potencies in inhibiting synaptosomal serotonin uptake. Serotonin uptake sites labeled by 3H-paroxetine were highly concentrated in the dorsal and median raphe nuclei, central gray, superficial layer of the superior colliculus, lateral septal nucleus, paraventricular nucleus of the thalamus, and the islands of Calleja. High concentrations of 3H-paroxetine binding sites were found in brainstem areas containing dopamine (substantia nigra and ventral tegmental area) and norepinephrine (locus coeruleus) cell bodies. Moderate concentrations of 3H-paroxetine binding sites were present in laminae I and IV of the frontal parietal cortex, primary olfactory cortex, olfactory tubercle, regions of the basal ganglia, septum, amygdala, thalamus, hypothalamus, hippocampus, and some brainstem areas including the interpeduncular, trigeminal, and parabrachial nuclei. Lower densities of 3H-paroxetine binding sites were found in other regions of the neocortex and very low to nonsignificant levels of binding were present in white matter tracts and in the cerebellum. Lesioning of serotonin neurons with 3,4-methylenedioxyamphetamine caused large decreases in 3H-paroxetine binding. The autoradiographic distribution of 3H-paroxetine binding sites in rat brain corresponds extremely well to the distribution of serotonin terminals and cell bodies as well as with the pharmacological sites of action of serotonin

Noradrenergic lesioning with an anti-dopamine beta-hydroxylase immunotoxin

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Picklo, M. J.; Wiley, R. G.; Lappi, D. A.; Robertson, D.

1994-01-01

Sympathectomy has been achieved by a variety of methods but each has its limitations. These include lack of tissue specificity, incomplete lesioning, and the age range of susceptibility to the lesioning. To circumvent these drawbacks, an immunotoxin was constructed using a monoclonal antibody against the noradrenergic specific enzyme dopamine beta-hydroxylase (D beta H) coupled via a disulfide bond to saporin, a ribosomal inactivating protein. Three days after intravenous injection of the anti-D beta H immunotoxin (50 micrograms) into adult Sprague-Dawley rats, 66% of neurons in the superior cervical ganglia were chromatolytic. Superior cervical ganglia neurons were poisoned in 1 day old and 1 week old (86% of neurons) neonatal rats following subcutaneous injection of 3.75 and 15 micrograms, respectively. The anti-D beta H immunotoxin will be a useful tool in the study of the peripheral noradrenergic system in adult and neonatal animals.

Stimulation of the noradrenergic system during memory formation impairs extinction learning but not the disruption of reconsolidation

NARCIS (Netherlands)

Soeter, M.; Kindt, M.

2012-01-01

The noradrenergic system plays a critical role in the ‘consolidation’ of emotional memory. If we are to target ‘reconsolidation’ in patients with anxiety disorders, the noradrenergic strengthening of fear memory should not impair the disruption of reconsolidation. In Experiment I, we addressed this

Electrophysiological and neurochemical changes in the rat hippocampus after in vitro and in vivo treatments with cocaine

International Nuclear Information System (INIS)

Yasuda, R.P.

1986-01-01

The in vitro and in vivo effects of cocaine in the noradrenergic pathway in the rat hippocampus were examined. Although the blockade of [ 3 H]-norepinephrine-uptake by cocaine has been well-characterized in both the central and peripheral nervous systems, investigations characterizing the electrophysiological effects of cocaine in the central nervous system have been limited. The first part of this thesis examines the relationship between the ability of cocaine to potentiate the electrophysiological response to norepinephrine (NE) and the ability of cocaine to block noradrenergic high affinity uptake in rat hippocampal slices. The second part of this thesis examines the effects of the repeated administration of cocaine on noradrenergic pre- and postsynaptic function and receptors of the rat hippocampus. These studies demonstrate that after repeated administration of cocaine (10 mg/kg/day) for 8 and 14 days there is a 50% decrease in NE high affinity uptake in the rat hippocampus. This was accompanied by a 40% increase in a binding site for NE uptake inhibitors at 14 days. In contrast to these effects, there was no effect on β-adrenergic receptor number or the isoproterenol induced electrophysiological responsiveness in the rat hippocampus. The conclusion of these studies is that the repeated administration of cocaine has a greater effect on presynaptic targets in the noradrenergic system than on postsynaptic neurons

Fractal analysis of striatal dopamine re-uptake sites

International Nuclear Information System (INIS)

Kuikka, J.T.; Bergstroem, K.A.; Tiihonen, J.; Raesaenen, P.; Karhu, J.

1997-01-01

Spatial variation in regional blood flow, metabolism and receptor density within the brain and in other organs is measurable even with a low spatial resolution technique such as emission tomography. It has been previously shown that the observed variance increases with increasing number of subregions in the organ/tissue studied. This resolution-dependent variance can be described by fractal analysis. We studied striatal dopamine re-uptake sites in 39 healthy volunteers with high-resolution single-photon emission tomography using iodine-123 labelled 2β-carbomethoxy-3β-(4-iodophenyl)tropane ([ 123 I]β-CIT). The mean fractal dimension was 1.15±0.07. The results indicate that regional striatal dopamine re-uptake sites involve considerable spatial heterogeneity which is higher than the uniform density (dimension=1.00) but much lower than complete randomness (dimension=1.50). There was a gender difference, with females having a higher heterogeneity in both the left and the right striatum. In addition, we found striatal asymmetry (left-to-right heterogeneity ratio of 1.19±0.15; P<0.001), suggesting functional hemispheric lateralization consistent with the control of motor behaviour and integrative functions. (orig.). With 5 figs., 1 tab

Fractal analysis of striatal dopamine re-uptake sites

Energy Technology Data Exchange (ETDEWEB)

Kuikka, J.T.; Bergstroem, K.A. [Department of Clinical Physiology, Kuopio University Hospital, Kuopio (Finland); Tiihonen, J.; Raesaenen, P. [Department of Forensic Psychiatry, University of Kuopio and Niuvanniemi Hospital, Kuopio (Finland); Karhu, J. [Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio (Finland)

1997-09-01

Spatial variation in regional blood flow, metabolism and receptor density within the brain and in other organs is measurable even with a low spatial resolution technique such as emission tomography. It has been previously shown that the observed variance increases with increasing number of subregions in the organ/tissue studied. This resolution-dependent variance can be described by fractal analysis. We studied striatal dopamine re-uptake sites in 39 healthy volunteers with high-resolution single-photon emission tomography using iodine-123 labelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ([{sup 123}I]{beta}-CIT). The mean fractal dimension was 1.15{+-}0.07. The results indicate that regional striatal dopamine re-uptake sites involve considerable spatial heterogeneity which is higher than the uniform density (dimension=1.00) but much lower than complete randomness (dimension=1.50). There was a gender difference, with females having a higher heterogeneity in both the left and the right striatum. In addition, we found striatal asymmetry (left-to-right heterogeneity ratio of 1.19{+-}0.15; P<0.001), suggesting functional hemispheric lateralization consistent with the control of motor behaviour and integrative functions. (orig.). With 5 figs., 1 tab.

Functional neuroanatomy of the central noradrenergic system.

Science.gov (United States)

Szabadi, Elemer

2013-08-01

The central noradrenergic neurone, like the peripheral sympathetic neurone, is characterized by a diffusely arborizing terminal axonal network. The central neurones aggregate in distinct brainstem nuclei, of which the locus coeruleus (LC) is the most prominent. LC neurones project widely to most areas of the neuraxis, where they mediate dual effects: neuronal excitation by α₁-adrenoceptors and inhibition by α₂-adrenoceptors. The LC plays an important role in physiological regulatory networks. In the sleep/arousal network the LC promotes wakefulness, via excitatory projections to the cerebral cortex and other wakefulness-promoting nuclei, and inhibitory projections to sleep-promoting nuclei. The LC, together with other pontine noradrenergic nuclei, modulates autonomic functions by excitatory projections to preganglionic sympathetic, and inhibitory projections to preganglionic parasympathetic neurones. The LC also modulates the acute effects of light on physiological functions ('photomodulation'): stimulation of arousal and sympathetic activity by light via the LC opposes the inhibitory effects of light mediated by the ventrolateral preoptic nucleus on arousal and by the paraventricular nucleus on sympathetic activity. Photostimulation of arousal by light via the LC may enable diurnal animals to function during daytime. LC neurones degenerate early and progressively in Parkinson's disease and Alzheimer's disease, leading to cognitive impairment, depression and sleep disturbance.

Chlorotoxin-mediated disinhibition of noradrenergic locus coeruleus neurons using a conditional transgenic approach.

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Salbaum, J Michael; Cirelli, Chiara; Walcott, Elisabeth; Krushel, Les A; Edelman, Gerald M; Tononi, Giulio

2004-07-30

The noradrenergic locus coeruleus (LC) has been implicated in the promotion of arousal, in focused attention and learning, and in the regulation of the sleep/waking cycle. The complex biological functions of the central noradrenergic system have been investigated largely through electrophysiological recordings and neurotoxic lesions of LC neurons. Activation of LC neurons through electrical or chemical stimulation has also led to important insights, although these techniques have limited cellular specificity and short-term effects. Here, we describe a novel method aimed at stimulating the central noradrenergic system in a highly selective manner for prolonged periods of time. This was achieved through the conditional expression of a transgene for chlorotoxin (Cltx) in the LC of adult mice. Chlorotoxin is a component of scorpion venom that partially blocks small conductance chloride channels. In this manner, the influence of GABAergic and glycinergic inhibitory inputs on LC cells is greatly reduced, while their ability to respond to excitatory inputs is unaffected. We demonstrate that the unilateral induction of Cltx expression in the LC is associated with a concomitant ipsilateral increase in the expression of markers of noradrenergic activity in LC neurons. Moreover, LC disinhibition is associated with the ipsilateral induction of the immediate early gene NGFI-A in cortical and subcortical target areas. Unlike previous gain of function approaches, transgenic disinhibition of LC cells is highly selective and persists for at least several weeks. This method represents a powerful new tool to assess the long-term effects of LC activation and is potentially applicable to other neuronal systems.

Noradrenergic activation of the basolateral amygdala modulates the consolidation of object-in-context recognition memory

OpenAIRE

Barsegyan, Areg; McGaugh, James L.; Roozendaal, Benno

2014-01-01

Noradrenergic activation of the basolateral complex of the amygdala (BLA) is well known to enhance the consolidation of long-term memory of highly emotionally arousing training experiences. The present study investigated whether such noradrenergic activation of the BLA also influences the consolidation of object-in-context recognition memory, a low-arousing training task assessing episodic-like memory. Male Sprague-Dawley rats were exposed to two identical objects in one context for either 3 ...

Noradrenergic control of gene expression and long-term neuronal adaptation evoked by learned vocalizations in songbirds.

Directory of Open Access Journals (Sweden)

Tarciso A F Velho

Full Text Available Norepinephrine (NE is thought to play important roles in the consolidation and retrieval of long-term memories, but its role in the processing and memorization of complex acoustic signals used for vocal communication has yet to be determined. We have used a combination of gene expression analysis, electrophysiological recordings and pharmacological manipulations in zebra finches to examine the role of noradrenergic transmission in the brain's response to birdsong, a learned vocal behavior that shares important features with human speech. We show that noradrenergic transmission is required for both the expression of activity-dependent genes and the long-term maintenance of stimulus-specific electrophysiological adaptation that are induced in central auditory neurons by stimulation with birdsong. Specifically, we show that the caudomedial nidopallium (NCM, an area directly involved in the auditory processing and memorization of birdsong, receives strong noradrenergic innervation. Song-responsive neurons in this area express α-adrenergic receptors and are in close proximity to noradrenergic terminals. We further show that local α-adrenergic antagonism interferes with song-induced gene expression, without affecting spontaneous or evoked electrophysiological activity, thus dissociating the molecular and electrophysiological responses to song. Moreover, α-adrenergic antagonism disrupts the maintenance but not the acquisition of the adapted physiological state. We suggest that the noradrenergic system regulates long-term changes in song-responsive neurons by modulating the gene expression response that is associated with the electrophysiological activation triggered by song. We also suggest that this mechanism may be an important contributor to long-term auditory memories of learned vocalizations.

Vascular Mural Cells Promote Noradrenergic Differentiation of Embryonic Sympathetic Neurons

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Vitor Fortuna

2015-06-01

Full Text Available The sympathetic nervous system controls smooth muscle tone and heart rate in the cardiovascular system. Postganglionic sympathetic neurons (SNs develop in close proximity to the dorsal aorta (DA and innervate visceral smooth muscle targets. Here, we use the zebrafish embryo to ask whether the DA is required for SN development. We show that noradrenergic (NA differentiation of SN precursors temporally coincides with vascular mural cell (VMC recruitment to the DA and vascular maturation. Blocking vascular maturation inhibits VMC recruitment and blocks NA differentiation of SN precursors. Inhibition of platelet-derived growth factor receptor (PDGFR signaling prevents VMC differentiation and also blocks NA differentiation of SN precursors. NA differentiation is normal in cloche mutants that are devoid of endothelial cells but have VMCs. Thus, PDGFR-mediated mural cell recruitment mediates neurovascular interactions between the aorta and sympathetic precursors and promotes their noradrenergic differentiation.

Neuropeptide S interacts with the basolateral amygdala noradrenergic system in facilitating object recognition memory consolidation.

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Han, Ren-Wen; Xu, Hong-Jiao; Zhang, Rui-San; Wang, Pei; Chang, Min; Peng, Ya-Li; Deng, Ke-Yu; Wang, Rui

2014-01-01

The noradrenergic activity in the basolateral amygdala (BLA) was reported to be involved in the regulation of object recognition memory. As the BLA expresses high density of receptors for Neuropeptide S (NPS), we investigated whether the BLA is involved in mediating NPS's effects on object recognition memory consolidation and whether such effects require noradrenergic activity. Intracerebroventricular infusion of NPS (1nmol) post training facilitated 24-h memory in a mouse novel object recognition task. The memory-enhancing effect of NPS could be blocked by the β-adrenoceptor antagonist propranolol. Furthermore, post-training intra-BLA infusions of NPS (0.5nmol/side) improved 24-h memory for objects, which was impaired by co-administration of propranolol (0.5μg/side). Taken together, these results indicate that NPS interacts with the BLA noradrenergic system in improving object recognition memory during consolidation. Copyright © 2013 Elsevier Inc. All rights reserved.

Calibration of a Plant Uptake Model with Plant- and Site-Specific. Data for Uptake of Chlorinated Organic Compounds into Radish

DEFF Research Database (Denmark)

Trapp, Stefan

2015-01-01

The uptake of organic pollutants by plants is an important process for the exposure of humans to toxic chemicals. The objective of this study was to calibrate the parameters of a common plant uptake model by comparison to experimental results from literature. Radish was grown in contaminated soil...... with default data and site-specific data were similar. Deposition from air was the major uptake mechanism into shoots. Transport from soil with resuspended particles was only relevant for the contaminated plot. The calculation results (in dry weight) were most sensitive to changes of the water content of plant...

Vascular Mural Cells Promote Noradrenergic Differentiation of Embryonic Sympathetic Neurons.

Science.gov (United States)

Fortuna, Vitor; Pardanaud, Luc; Brunet, Isabelle; Ola, Roxana; Ristori, Emma; Santoro, Massimo M; Nicoli, Stefania; Eichmann, Anne

2015-06-23

The sympathetic nervous system controls smooth muscle tone and heart rate in the cardiovascular system. Postganglionic sympathetic neurons (SNs) develop in close proximity to the dorsal aorta (DA) and innervate visceral smooth muscle targets. Here, we use the zebrafish embryo to ask whether the DA is required for SN development. We show that noradrenergic (NA) differentiation of SN precursors temporally coincides with vascular mural cell (VMC) recruitment to the DA and vascular maturation. Blocking vascular maturation inhibits VMC recruitment and blocks NA differentiation of SN precursors. Inhibition of platelet-derived growth factor receptor (PDGFR) signaling prevents VMC differentiation and also blocks NA differentiation of SN precursors. NA differentiation is normal in cloche mutants that are devoid of endothelial cells but have VMCs. Thus, PDGFR-mediated mural cell recruitment mediates neurovascular interactions between the aorta and sympathetic precursors and promotes their noradrenergic differentiation. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Noradrenergic α1 Receptor Antagonist Treatment Attenuates Positive Subjective Effects of Cocaine in Humans: A Randomized Trial

Science.gov (United States)

Newton, Thomas F.; De La Garza, Richard; Brown, Gregory; Kosten, Thomas R.; Mahoney, James J.; Haile, Colin N.

2012-01-01

Background Preclinical research implicates dopaminergic and noradrenergic mechanisms in mediating the reinforcing effects of drugs of abuse, including cocaine. The objective of this study was to evaluate the impact of treatment with the noradrenergic α1 receptor antagonist doxazosin on the positive subjective effects of cocaine. Methods Thirteen non-treatment seeking, cocaine-dependent volunteers completed this single-site, randomized, placebo-controlled, within-subjects study. In one study phase volunteers received placebo and in the other they received doxazosin, with the order counterbalanced across participants. Study medication was masked by over-encapsulating doxazosin tablets and matched placebo lactose served as the control. Study medication treatment was initiated at 1 mg doxazosin or equivalent number of placebo capsules PO/day and increased every three days by 1 mg. After receiving 4 mg doxazosin or equivalent number of placebo capsules participants received masked doses of 20 and 40 mg cocaine IV in that order with placebo saline randomly interspersed to maintain the blind. Results Doxazosin treatment was well tolerated and doxazosin alone produced minimal changes in heart rate and blood pressure. During treatment with placebo, cocaine produced dose-dependent increases in subjective effect ratings of “high”, “stimulated”, “like cocaine”, “desire cocaine”, “any drug effect”, and “likely to use cocaine if had access” (p<.001). Doxazosin treatment significantly attenuated the effects of 20 mg cocaine on ratings of “stimulated”, “like cocaine”, and “likely to use cocaine if had access” (p<.05). There were trends for doxazosin to reduce ratings of “stimulated”, “desire cocaine”, and “likely to use cocaine if had access” (p<.10). Conclusions Medications that block noradrenergic α1 receptors, such as doxazosin, may be useful as treatments for cocaine dependence, and should be evaluated further. Trial

Noradrenergic deficits in Parkinson's disease imaged with (11)C-MeNER

DEFF Research Database (Denmark)

Nahimi, Adjmal; Sommerauer, Michael; Kinnerup, Martin B

2017-01-01

significant declines in the thalamus, hypothalamus, and nucleus ruber. Tremor was significantly associated with preserved tracer binding. Conclusion: This is first specific quantification of noradrenergic denervation in Parkinsonńs disease patients in vivo. In agreement with predictions from determinations...

Human amygdala reactivity is diminished by the beta-noradrenergic antagonist propranolol

NARCIS (Netherlands)

Hurlemann, R.; Walter, H.; Rehme, A. K.; Kukolja, J.; Santoro, S. C.; Schmidt, C.; Schnell, K.; Musshoff, F.; Keysers, C.; Maier, W.; Kendrick, K. M.; Onur, O. A.

Background. Animal models of anxiety disorders emphasize the crucial role of locus ceruleus-noradrenergic (norepinephrine, NE) signaling, the basolateral amygdala (BLA) and their interactions in the expression of anxiety-like behavioral responses to stress. Despite clinical evidence for the efficacy

Combined Effects of Glucocorticoid and Noradrenergic Activity on Loss Aversion.

Science.gov (United States)

Margittai, Zsofia; Nave, Gideon; Van Wingerden, Marijn; Schnitzler, Alfons; Schwabe, Lars; Kalenscher, Tobias

2018-01-01

Loss aversion is a well-known behavioral regularity in financial decision making, describing humans' tendency to overweigh losses compared to gains of the same amount. Recent research indicates that stress and associated hormonal changes affect loss aversion, yet the underlying neuroendocrine mechanisms are still poorly understood. Here, we investigated the causal influence of two major stress neuromodulators, cortisol and noradrenaline, on loss aversion during financial decision making. In a double-blind, placebo-controlled between-subject design, we orally administered either the α2-adrenergic antagonist yohimbine (increasing noradrenergic stimulation), hydrocortisone, both substances, or a placebo to healthy young men. We tested the treatments' influence on a financial decision-making task measuring loss aversion and risk attitude. We found that both drugs combined, relative to either drug by itself, reduced loss aversion in the absence of an effect on risk attitude or choice consistency. Our data suggest that concurrent glucocorticoid and noradrenergic activity prompts an alignment of reward- with loss-sensitivity, and thus diminishes loss aversion. Our results have implications for the understanding of the susceptibility to biases in decision making.

Noradrenergic and GABAergic systems in the medial hypothalamus are activated during hypoglycemia

NARCIS (Netherlands)

Beverly, JL; De Vries, MG; Bouman, SD; Arseneau, LM

Noradrenergic and GABAergic systems in the medial hypothalamus influence plasma glucose and may be activated during glucoprivation. Microdialysis probes were placed into the ventromedial nucleus (VMH), lateral hypothalamus (LHA), and paraventricular nucleus (PVH) of male Sprague-Dawley rats to

Prenatal drug exposures sensitize noradrenergic circuits to subsequent disruption by chlorpyrifos.

Science.gov (United States)

Slotkin, Theodore A; Skavicus, Samantha; Seidler, Frederic J

2015-12-02

We examined whether nicotine or dexamethasone, common prenatal drug exposures, sensitize the developing brain to chlorpyrifos. We gave nicotine to pregnant rats throughout gestation at a dose (3mg/kg/day) producing plasma levels typical of smokers; offspring were then given chlorpyrifos on postnatal days 1-4, at a dose (1mg/kg) that produces minimally-detectable inhibition of brain cholinesterase activity. In a parallel study, we administered dexamethasone to pregnant rats on gestational days 17-19 at a standard therapeutic dose (0.2mg/kg) used in the management of preterm labor, followed by postnatal chlorpyrifos. We evaluated cerebellar noradrenergic projections, a known target for each agent, and contrasted the effects with those in the cerebral cortex. Either drug augmented the effect of chlorpyrifos, evidenced by deficits in cerebellar β-adrenergic receptors; the receptor effects were not due to increased systemic toxicity or cholinesterase inhibition, nor to altered chlorpyrifos pharmacokinetics. Further, the deficits were not secondary adaptations to presynaptic hyperinnervation/hyperactivity, as there were significant deficits in presynaptic norepinephrine levels that would serve to augment the functional consequence of receptor deficits. The pretreatments also altered development of cerebrocortical noradrenergic circuits, but with a different overall pattern, reflecting the dissimilar developmental stages of the regions at the time of exposure. However, in each case the net effects represented a change in the developmental trajectory of noradrenergic circuits, rather than simply a continuation of an initial injury. Our results point to the ability of prenatal drug exposure to create a subpopulation with heightened vulnerability to environmental neurotoxicants. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Modulation of the noradrenergic receptor at uterine level by the 17 β-estradiol influence

International Nuclear Information System (INIS)

Vanderlei, F.H.F.; Catanho, M.T.J.

1991-01-01

The present study was undertaken to asses the regulation of the noradrenergic receptor, by estrogens. We measured the uterotrophic response and the binding capacity of the noradrenergic receptor after the administration of 17 β-estradiol (E sub(2); 132 nmol/kg b.w., i.p.) to immature rats. The results showed that 2 and 4 hs after E sub(2) treatment, the total number of NA-receptors enhanced significantly (6 fold). Similarly, it was observed a significant increase in uterine weight, 24 h after E sub(2) administration. The results indicate that NA-receptors present in the uterus may be under a direct E sub(2) regulation, which suggests a possible participation on the uterotropic response induced by E sub(2). (author)

Noradrenergic action in prefrontal cortex in the late stage of memory consolidation

NARCIS (Netherlands)

Tronel, Sophie; Feenstra, Matthijs G. P.; Sara, Susan J.

2004-01-01

These experiments investigated the role of the noradrenergic system in the late stage of memory consolidation and in particular its action at beta receptors in the prelimbic region (PL) of the prefrontal cortex in the hours after training. Rats were trained in a rapidly acquired, appetitively

Exemplifying whole-plant ozone uptake in adult forest trees of contrasting species and site conditions

International Nuclear Information System (INIS)

Nunn, Angela J.; Wieser, Gerhard; Metzger, Ursula; Loew, Markus; Wipfler, Philip; Haeberle, Karl-Heinz; Matyssek, Rainer

2007-01-01

Whole-tree O 3 uptake was exemplified for Picea abies, Fagus sylvatica and Larix decidua in stands at high and low altitude and contrasting water availability through sap flow measurement in tree trunks, intrinsically accounting for drought and boundary layer effects on O 3 flux. O 3 uptake of evergreen spruce per unit foliage area was enhanced by 100% at high relative to low elevation, whereas deciduous beech and larch showed similar uptake regardless of altitude. The responsiveness of the canopy conductance to water vapor and, as a consequence, O 3 uptake to soil moisture and air humidity did not differ between species. Unifying findings at the whole-tree level will promote cause-effect based O 3 risk assessment and modeling. - Sap flow-based assessment of whole-tree O 3 uptake reflects similar responsiveness of canopy conductance and O 3 uptake across contrasting tree species and site conditions

The antidepressant-like effect of ethynyl estradiol is mediated by both serotonergic and noradrenergic systems in the forced swimming test.

Science.gov (United States)

Vega-Rivera, N M; López-Rubalcava, C; Estrada-Camarena, E

2013-10-10

17α-Ethynyl-estradiol (EE2, a synthetic steroidal estrogen) induces antidepressant-like effects in the forced swimming test (FST) similar to those induced by 5-HT and noradrenaline reuptake inhibitors (dual antidepressants). However, the precise mechanism of action of EE2 has not been studied. In the present study, the participation of estrogen receptors (ERs) and the serotonergic and the noradrenergic presynaptic sites in the antidepressant-like action of EE2 was evaluated in the FST. The effects of the ER antagonist ICI 182,780 (10 μg/rat; i.c.v.), the serotonergic and noradrenergic terminal destruction with 5,7-dihydroxytryptamine (5,7-DHT; 200 μg/rat, i.c.v.), and N-(2-chloro-ethyl)-N-ethyl-2-bromobenzylamine (DSP4; 10mg/kg, i.p.) were studied in ovariectomized rats treated with EE2 and subjected to the FST. In addition, the participation of α2-adrenergic receptors in the antidepressant-like action of EE2 was explored using the selective α2-receptor antagonist idazoxan (0.25, 0.5 and 1.0mg/kg, i.p.). EE2 induced an antidepressant-like action characterized by a decrease in immobility behavior with a concomitant increase in swimming and climbing behaviors. The ER antagonist, 5,7-DHT, DSP4, and idazoxan blocked the effects of EE2 on the immobility behavior, whereas ICI 182,780 and 5,7-DHT affected swimming behavior. The noradrenergic compound DSP4 altered climbing behavior, while Idazoxan inhibited the increase of swimming and climbing behaviors induced by EE2. Our results suggest that the antidepressant-like action of EE2 implies a complex mechanism of action on monoaminergic systems and estrogen receptors. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

The inhibition of the dorsal paragigantocellular reticular nucleus induces waking and the activation of all adrenergic and noradrenergic neurons: a combined pharmacological and functional neuroanatomical study.

Science.gov (United States)

Clément, Olivier; Valencia Garcia, Sara; Libourel, Paul-Antoine; Arthaud, Sébastien; Fort, Patrice; Luppi, Pierre-Hervé

2014-01-01

GABAergic neurons specifically active during paradoxical sleep (PS) localized in the dorsal paragigantocellular reticular nucleus (DPGi) are known to be responsible for the cessation of activity of the noradrenergic neurons of the locus coeruleus during PS. In the present study, we therefore sought to determine the role of the DPGi in PS onset and maintenance and in the inhibition of the LC noradrenergic neurons during this state. The effect of the inactivation of DPGi neurons on the sleep-waking cycle was examined in rats by microinjection of muscimol, a GABAA agonist, or clonidine, an alpha-2 adrenergic receptor agonist. Combining immunostaining of the different populations of wake-inducing neurons with that of c-FOS, we then determined whether muscimol inhibition of the DPGi specifically induces the activation of the noradrenergic neurons of the LC. Slow wave sleep and PS were abolished during 3 and 5 h after muscimol injection in the DPGi, respectively. The application of clonidine in the DPGi specifically induced a significant decrease in PS quantities and delayed PS appearance compared to NaCl. We further surprisingly found out that more than 75% of the noradrenergic and adrenergic neurons of all adrenergic and noradrenergic cell groups are activated after muscimol treatment in contrast to the other wake active systems significantly less activated. These results suggest that, in addition to its already know inhibition of LC noradrenergic neurons during PS, the DPGi might inhibit the activity of noradrenergic and adrenergic neurons from all groups during PS, but also to a minor extent during SWS and waking.

The inhibition of the dorsal paragigantocellular reticular nucleus induces waking and the activation of all adrenergic and noradrenergic neurons: a combined pharmacological and functional neuroanatomical study.

Directory of Open Access Journals (Sweden)

Olivier Clément

Full Text Available GABAergic neurons specifically active during paradoxical sleep (PS localized in the dorsal paragigantocellular reticular nucleus (DPGi are known to be responsible for the cessation of activity of the noradrenergic neurons of the locus coeruleus during PS. In the present study, we therefore sought to determine the role of the DPGi in PS onset and maintenance and in the inhibition of the LC noradrenergic neurons during this state. The effect of the inactivation of DPGi neurons on the sleep-waking cycle was examined in rats by microinjection of muscimol, a GABAA agonist, or clonidine, an alpha-2 adrenergic receptor agonist. Combining immunostaining of the different populations of wake-inducing neurons with that of c-FOS, we then determined whether muscimol inhibition of the DPGi specifically induces the activation of the noradrenergic neurons of the LC. Slow wave sleep and PS were abolished during 3 and 5 h after muscimol injection in the DPGi, respectively. The application of clonidine in the DPGi specifically induced a significant decrease in PS quantities and delayed PS appearance compared to NaCl. We further surprisingly found out that more than 75% of the noradrenergic and adrenergic neurons of all adrenergic and noradrenergic cell groups are activated after muscimol treatment in contrast to the other wake active systems significantly less activated. These results suggest that, in addition to its already know inhibition of LC noradrenergic neurons during PS, the DPGi might inhibit the activity of noradrenergic and adrenergic neurons from all groups during PS, but also to a minor extent during SWS and waking.

Native Plant Uptake Model for Radioactive Waste Disposal Areas at the Nevada Test Site

Energy Technology Data Exchange (ETDEWEB)

BROWN,THERESA J.; WIRTH,SHARON

1999-09-01

This report defines and defends the basic framework, methodology, and associated input parameters for modeling plant uptake of radionuclides for use in Performance Assessment (PA) activities of Radioactive Waste Management Sites (RWMS) at the Nevada Test Site (NTS). PAs are used to help determine whether waste disposal configurations meet applicable regulatory standards for the protection of human health, the environment, or both. Plants adapted to the arid climate of the NTS are able to rapidly capture infiltrating moisture. In addition to capturing soil moisture, plant roots absorb nutrients, minerals, and heavy metals, transporting them within the plant to the above-ground biomass. In this fashion, plant uptake affects the movement of radionuclides. The plant uptake model presented reflects rooting characteristics important to plant uptake, biomass turnover rates, and the ability of plants to uptake radionuclides from the soil. Parameters are provided for modeling plant uptake and estimating surface contaminant flux due to plant uptake under both current and potential future climate conditions with increased effective soil moisture. The term ''effective moisture'' is used throughout this report to indicate the soil moisture that is available to plants and is intended to be inclusive of all the variables that control soil moisture at a site (e.g., precipitation, temperature, soil texture, and soil chemistry). Effective moisture is a concept used to simplify a number of complex, interrelated soil processes for which there are too little data to model actual plant available moisture. The PA simulates both the flux of radionuclides across the land surface and the potential dose to humans from that flux. Surface flux is modeled here as the amount of soil contamination that is transferred from the soil by roots and incorporated into aboveground biomass. Movement of contaminants to the surface is the only transport mechanism evaluated with the model

Native Plant Uptake Model for Radioactive Waste Disposal Areas at the Nevada Test Site

International Nuclear Information System (INIS)

Brown, Theresa J.; Wirth, Sharon

1999-01-01

This report defines and defends the basic framework, methodology, and associated input parameters for modeling plant uptake of radionuclides for use in Performance Assessment (PA) activities of Radioactive Waste Management Sites (RWMS) at the Nevada Test Site (NTS). PAs are used to help determine whether waste disposal configurations meet applicable regulatory standards for the protection of human health, the environment, or both. Plants adapted to the arid climate of the NTS are able to rapidly capture infiltrating moisture. In addition to capturing soil moisture, plant roots absorb nutrients, minerals, and heavy metals, transporting them within the plant to the above-ground biomass. In this fashion, plant uptake affects the movement of radionuclides. The plant uptake model presented reflects rooting characteristics important to plant uptake, biomass turnover rates, and the ability of plants to uptake radionuclides from the soil. Parameters are provided for modeling plant uptake and estimating surface contaminant flux due to plant uptake under both current and potential future climate conditions with increased effective soil moisture. The term ''effective moisture'' is used throughout this report to indicate the soil moisture that is available to plants and is intended to be inclusive of all the variables that control soil moisture at a site (e.g., precipitation, temperature, soil texture, and soil chemistry). Effective moisture is a concept used to simplify a number of complex, interrelated soil processes for which there are too little data to model actual plant available moisture. The PA simulates both the flux of radionuclides across the land surface and the potential dose to humans from that flux. Surface flux is modeled here as the amount of soil contamination that is transferred from the soil by roots and incorporated into aboveground biomass. Movement of contaminants to the surface is the only transport mechanism evaluated with the model presented here

One-single physical exercise session after object recognition learning promotes memory persistence through hippocampal noradrenergic mechanisms.

Science.gov (United States)

da Silva de Vargas, Liane; Neves, Ben-Hur Souto das; Roehrs, Rafael; Izquierdo, Iván; Mello-Carpes, Pâmela

2017-06-30

Previously we showed the involvement of the hippocampal noradrenergic system in the consolidation and persistence of object recognition (OR) memory. Here we show that one-single physical exercise session performed immediately after learning promotes OR memory persistence and increases norepinephrine levels in the hippocampus. Additionally, effects of exercise on memory are avoided by an intra-hippocampal beta-adrenergic antagonist infusion. Taken together, these results suggest that exercise effects on memory can be related to noradrenergic mechanisms and acute physical exercise can be a non-pharmacological intervention to assist memory consolidation and persistence, with few or no side effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Similarity of nutrient uptake and root dimensions of Engelmann spruce and subalpine fir at two contrasting sites in Colorado

Energy Technology Data Exchange (ETDEWEB)

Yanai, R; McFarlane, K; Lucash, M; Kulpa, S; Wood, D

2009-10-09

Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this assumption by measuring the nutrient uptake capacity of intact roots of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) at Loch Vale Watershed and Fraser Experimental Forest in the Rocky Mountains of central Colorado. Roots still attached to the tree were exposed to one of three concentrations of nutrient solutions for time periods ranging from 1 to 96 hours, and solutions were analyzed for ammonium, nitrate, calcium, magnesium, and potassium. Surprisingly, the two species were indistinguishable in nutrient uptake within site for all nutrients (P > 0.25), but uptake rates differed by site. In general, nutrient uptake was higher at Fraser (P = 0.01, 0.15, 0.03, 0.18 for NH{sub 4}{sup +}, NO{sub 3}{sup -}, Ca{sup 2+}, and K{sup +}, respectively), which is west of the Continental Divide and has lower atmospheric deposition of N than Loch Vale. Mean uptake rates by site for ambient solution concentrations were 0.12 {micro}mol NH{sub 4}{sup +} g{sub fwt}{sup -1} h{sup -1}, 0.02 {micro}mol NO{sub 3}{sup -} g{sub fwt}{sup -1}, 0.21 {micro}mol Ca{sup 2+} g{sub fwt}{sup -1} h{sup -1}, and 0.01 {micro}mol Mg{sup 2+} g{sub fwt}{sup -1} h{sup -1} at Loch Vale, and 0.21 {micro}mol NH{sub 4}{sup +} f{sub fwt}{sup -1}h{sup -1}, 0.04 {micro}mol NO{sub 3}{sup -} g{sub fwt}{sup -1} h{sup -1}, 0.51 {micro}mol Ca{sup 2+}g{sub fwt}{sup -1}h{sup -1}, and 0.07 {micro}mol Mg{sup 2+} f{sub fwt}{sup -1}h{sup -1} at Fraser. The importance of site conditions in determining uptake capacity should not be overlooked when parameterizing nutrient uptake models. We also characterized the root morphology of these two species and compared them to other tree species we have measured at various sites in the northeastern USA. Engelman spruce and subalpine fir

Rates and tissue sites of non-insulin- and insulin-mediated glucose uptake in humans

International Nuclear Information System (INIS)

Baron, A.D.; Brechtel, G.; Wallace, P.; Edelman, S.V.

1988-01-01

In vivo glucose uptake can occur via two mechanisms, namely, insulin-mediated glucose uptake (IMGU) and non-insulin-mediated glucose uptake (NIMGU). Although the principal tissue sites for IMGU are skeletal muscle, the tissue sites for NIMGU at a given serum glucose concentration are not known. To examine this issue, rates of whole body glucose uptake (Rd) were measured at basal and during glucose clamp studies performed at euglycemia (approximately 90 mg/dl) and hyperglycemia (approximately 220 mg/dl) in six lean healthy men. Studies were performed during hyperinsulinemia (approximately 70 microU/ml) and during somatostatin-induced insulinopenia to measure IMGU and NIMGU, respectively. During each study, leg glucose balance (arteriovenous catheter technique) was also measured. With this approach, rates of whole body skeletal muscle IMGU and NIMGU can be estimated, and the difference between overall Rd and skeletal muscle glucose uptake represents non-skeletal muscle Rd. The results indicate that approximately 20% of basal Rd is into skeletal muscle. During insulinopenia approximately 86% of body NIMGU occurs in non-skeletal muscle tissues at euglycemia. When hyperglycemia was created, whole body NIMGU increased from 128 +/- 6 to 213 +/- 18 mg/min (P less than 0.01); NIMGU into non-skeletal muscle tissues was 134 +/- 11 and 111 +/- 6 mg/min at hyperglycemia and euglycemia, respectively, P = NS. Therefore, virtually all the hyperglycemia induced increment in NIMGU occurred in skeletal muscle. During hyperinsulinemia, IMGU in skeletal muscle represented 75 and 95% of body Rd, at euglycemia and hyperglycemia, respectively

Distribution of 3H-GABA uptake sites in the nematode Ascaris

International Nuclear Information System (INIS)

Guastella, J.; Stretton, A.O.

1991-01-01

The distribution of uptake sites for the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the nematode Ascaris suum was examined by autoradiography of 3H-GABA uptake. Single neural processes in both the ventral and dorsal nerve cords were labeled with 3H-GABA. Serial section analysis identified the cells of origin of these processes as the RMEV-like and RMED-like neurons. These cells belong to a set of four neurons in the nerve ring, all of which are labeled by 3H-GABA. 3H-GABA labeling of at least two other sets of cephalic neurons was seen. One of these pairs consists of medium-sized lateral ganglia neurons, located at the level of the amphid commissure bundle. A second pair is located in the lateral ganglia at the level of the deirid commissure bundle. The position and size of these lateral ganglia cells suggest that they are the GABA-immunoreactive lateral ganglia cells frequently seen in whole-mount immunocytochemical preparations. Four neuronal cell bodies located in the retrovesicular ganglion were also labeled with 3H-GABA. These cells, which are probably cholinergic excitatory motor neurons, do not contain detectable GABA-like immunoreactivity. Heavy labeling of muscle cells was also observed. The ventral and dorsal nerve cord inhibitory motor neurons, which are known to contain GABA-like immunoreactivity, were not labeled above background with 3H-GABA. Together with the experiments reported previously, these results define three classes of GABA-associated neurons in Ascaris: (1) neurons that contain endogenous GABA and possess a GABA uptake system; (2) neurons that contain endogenous GABA, but that either lack a GABA uptake system or possess a GABA uptake system of low activity; (3) neurons that possess a GABA uptake system, but that lack endogenous GABA

Noradrenergic Action in Prefrontal Cortex in the Late Stage of Memory Consolidation

Science.gov (United States)

Tronel, Sophie; Feenstra, Matthijs G. P.; Sara, Susan J.

2004-01-01

These experiments investigated the role of the noradrenergic system in the late stage of memory consolidation and in particular its action at beta receptors in the prelimbic region (PL) of the prefrontal cortex in the hours after training. Rats were trained in a rapidly acquired, appetitively motivated foraging task based on olfactory…

Paraquat and maneb co-exposure induces noradrenergic locus coeruleus neurodegeneration through NADPH oxidase-mediated microglial activation

International Nuclear Information System (INIS)

Hou, Liyan; Zhang, Cong; Wang, Ke; Liu, Xiaofang; Wang, Hongwei; Che, Yuning; Sun, Fuqiang; Zhou, Xueying; Zhao, Xiulan; Wang, Qingshan

2017-01-01

Highlights: • Microglial activation induced by paraquat and maneb precedes noradrenergic neurodegeneration in locus coeruleus. • NADPH oxidase activation contributes to microglia-mediated neuroinflammation and related noradrenergic neurodegeneration. • Inhibition of NADPH oxidase by apocynin protects noradrenergic neurons against paraquat and maneb-induced toxicity. - Abstract: Co-exposure to paraquat (PQ) and maneb (Mb) has been shown to increase the risk of Parkinson’s disease (PD) and dopaminergic (DA) neurodegeneration in the substantia nigra pars compacta (SNpc) is observed in PQ and Mb-treated experimental animals. The loss of noradrenergic locus coeruleus (LC/NE) neurons in brainstem is a common feature shared by multiple neurodegenerative diseases, including PD. However, whether PQ and Mb is able to damage LC/NE neurons remains undefined. In this study, mice treated with combined PQ and Mb displayed progressive LC/NE neurodegeneration. Time course studies revealed that the activation of microglia preceded LC/NE neurodegeneration. Mechanistically, the activation of NADPH oxidase contributed to microglial activation and subsequent LC/NE neurodegeneration. We found that PQ and Mb co-exposure induced activation of NADPH oxidase as shown by increased superoxide production and membrane translocation of p47 phox , a cytosolic subunit of NADPH oxidase. Inhibition of NADPH oxidase by apocynin, a widely used NADPH oxidase inhibitor, suppressed microglial activation and gene expressions of proinflammatory factors. Furthermore, reduced activation of nuclear factor-κB (NF-κB) pathway was observed in apocynin-treated mice. More importantly, inhibition of NADPH oxidase by apocynin afforded LC/NE neuroprotection against PQ and Mb-induced neurotoxicity. Thus, our findings revealed the critical role NADPH oxidase-mediated microglial activation in driving LC/NE neurodegeneration induced by PQ and Mb, providing new insights into the pathogenesis of environmental

Glucocorticoid enhancement of dorsolateral striatum-dependent habit memory requires concurrent noradrenergic activity.

Science.gov (United States)

Goodman, J; Leong, K-C; Packard, M G

2015-12-17

Previous findings indicate that post-training administration of glucocorticoid stress hormones can interact with the noradrenergic system to enhance consolidation of hippocampus- or amygdala-dependent cognitive/emotional memory. The present experiments were designed to extend these findings by examining the potential interaction of glucocorticoid and noradrenergic mechanisms in enhancement of dorsolateral striatum (DLS)-dependent habit memory. In experiment 1, different groups of adult male Long-Evans rats received training in two DLS-dependent memory tasks. In a cued water maze task, rats were released from various start points and were reinforced to approach a visibly cued escape platform. In a response-learning version of the water plus-maze task, animals were released from opposite starting positions and were reinforced to make a consistent egocentric body-turn to reach a hidden escape platform. Immediately post-training, rats received peripheral injections of the glucocorticoid corticosterone (1 or 3 mg/kg) or vehicle solution. In both tasks, corticosterone (3 mg/kg) enhanced DLS-dependent habit memory. In experiment 2, a separate group of animals received training in the response learning version of the water plus-maze task and were given peripheral post-training injections of corticosterone (3 mg/kg), the β-adrenoreceptor antagonist propranolol (3 mg/kg), corticosterone and propranolol concurrently, or control vehicle solution. Corticosterone injections again enhanced DLS-dependent memory, and this effect was blocked by concurrent administration of propranolol. Propranolol administration by itself (3 mg/kg) did not influence DLS-dependent memory. Taken together, the findings indicate an interaction between glucocorticoid and noradrenergic mechanisms in DLS-dependent habit memory. Propranolol administration may be useful in treating stress-related human psychopathologies associated with a dysfunctional DLS-dependent habit memory system. Copyright © 2015

Uptake of selected organics and metals by terrestrial vegetation and insects at a site in Arizona

International Nuclear Information System (INIS)

Day, C.H.; Ayers, T.A.; Ellingson, S.B.; Braddy, L.

1995-01-01

As part of an investigation at a CERCLA site in Arizona, 27 potential sources of contamination (PSCS) were identified for study. A screening level ecological risk assessment was conducted for each PSC using generic plant uptake factors and conservative exposure parameters. Risk estimates were calculated for the indicator species using the hazard index (HI) approach. Results of the screening level assessment indicated that 4 of the 27 PSCs required further evaluation due to elevated HIs. The contaminants of potential concern (COPCS) are antimony, cadmium, lead, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and total petroleum hydrocarbons (TPH). A field sampling program at the 4 PSCs and a site-specific background location was conduct4ed to collect the food sources for the indicator species. The samples have been analyzed for the COPCs and the results are being used to validate the screening level risk calculations. The site-specific soil-to-plant uptake factors will be compared to generic soil-to-plant uptake factors obtained from the scientific literature, with emphasis placed on studies done in similar arid environments. Contaminant-specific soil-to-insect bioaccumulation factors (BAFs) will be presented and compared to BAFs derived using published bioaccumulation models

Non-malignant FDG uptake in infradiaphragmatic adipose tissue: a new site of physiological tracer biodistribution characterised by PET/CT

International Nuclear Information System (INIS)

Bar-Shalom, Rachel; Keidar, Zohar; Gaitini, Diana; Israel, Ora

2004-01-01

The purpose of this study was to characterise a benign pattern of infradiaphragmatic 18 F-fluorodeoxyglucose (FDG) uptake in cancer patients using PET/CT. Infradiaphragmatic foci of FDG uptake, localised by PET/CT in regions of normal fat tissues, were demonstrated, in conjunction with fatty uptake in the neck and shoulders, in 9 of 1,241 (0.7%) patients. The imaging and clinical characteristics of this pattern and its possible clinical significance were assessed. PET/CT precisely localised infradiaphragmatic fat uptake (IDFU) within normal retroperitoneal fatty tissue of the perirenal space (nine patients) and in the paracolic or parahepatic space (four patients). Perirenal uptake was bilateral in five patients and focal in six. Paracolic and parahepatic uptake was bilateral in three patients and linear in all four patients. There was no evidence of malignancy at any of the sites during a follow-up period of 9-21 months. IDFU was significantly more prevalent in young patients assessed for monitoring response to therapy, and was always associated with the benign supradiaphragmatic uptake pattern, although its prevalence was significantly lower. There were no significant differences between the clinical characteristics of these two patterns of benign fatty FDG uptake. It is concluded that PET/CT allows for precise identification of increased FDG uptake in abdominal fatty tissue and further exclusion of disease at such sites. This benign uptake may represent increased glucose consumption in activated brown adipose tissue, similar to the mechanism suggested for supradiaphragmatic uptake. Recognition of this benign IDFU pattern is important for correct interpretation of abdominal PET findings in cancer patients. (orig.)

Different components of 3H-imipramine binding in rat brain membranes: relation to serotonin uptake sites

International Nuclear Information System (INIS)

Gobbi, M.; Taddei, C.; Mennini, T.

1988-01-01

In the present paper, the authors confirm and extend previous studies showing heterogeneous 3 H-imipramine ( 3 H-IMI) binding sites. Inhibition curves of various drugs (serotonin, imipramine, desmethyl-imipramine, d-fenfluramine, d-norfenfluramine and indalpine, a potent serotonin uptake inhibitor) obtained using 2 nM 3 H-IMI and in presence of 120 mM NaCl, confirmed the presence of at least three 3 H-IMI binding sites: two of these were serotonin-insensitive while the third one was selectively inhibited by serotonin and indalpine with nanomolar affinities. Moreover this last component was found to be selectively modulated by chronic imipramine treatment thus suggesting a close relation to serontonin uptake mechanism. These data indicate that the use of a more selective inhibitors of the serotonin-sensitive component (like indalpine or serotonin itself) to define non specific 3 H-IMI, may be of help in understanding its relation with serotonin uptake system. 22 references, 2 figures, 2 tables

Adolescent social isolation increases anxiety-like behavior and ethanol intake and impairs fear extinction in adulthood: Possible role of disrupted noradrenergic signaling.

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Skelly, M J; Chappell, A E; Carter, E; Weiner, J L

2015-10-01

Alcohol use disorder, anxiety disorders, and post-traumatic stress disorder (PTSD) are highly comorbid, and exposure to chronic stress during adolescence may increase the incidence of these conditions in adulthood. Efforts to identify the common stress-related mechanisms driving these disorders have been hampered, in part, by a lack of reliable preclinical models that replicate their comorbid symptomatology. Prior work by us, and others, has shown that adolescent social isolation increases anxiety-like behaviors and voluntary ethanol consumption in adult male Long-Evans rats. Here we examined whether social isolation also produces deficiencies in extinction of conditioned fear, a hallmark symptom of PTSD. Additionally, as disrupted noradrenergic signaling may contribute to alcoholism, we examined the effect of anxiolytic medications that target noradrenergic signaling on ethanol intake following adolescent social isolation. Our results confirm and extend previous findings that adolescent social isolation increases anxiety-like behavior and enhances ethanol intake and preference in adulthood. Additionally, social isolation is associated with a significant deficit in the extinction of conditioned fear and a marked increase in the ability of noradrenergic therapeutics to decrease ethanol intake. These results suggest that adolescent social isolation not only leads to persistent increases in anxiety-like behaviors and ethanol consumption, but also disrupts fear extinction, and as such may be a useful preclinical model of stress-related psychopathology. Our data also suggest that disrupted noradrenergic signaling may contribute to escalated ethanol drinking following social isolation, thus further highlighting the potential utility of noradrenergic therapeutics in treating the deleterious behavioral sequelae associated with early life stress. Copyright © 2015 Elsevier Ltd. All rights reserved.

The dorsal tegmental noradrenergic projection: an analysis of its role in maze learning.

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Roberts, D C; Price, M T; Fibiger, H C

1976-04-01

The hypothesis that the noradrenergic projection from the locus coeruleus (LC) to the cerebral cortex and hippocampus is an important neural substrate for learning was evaluated. Maze performance was studied in rats receiving either electrolytic lesions of LC or 6-hydroxydopamine (6-OHDA) lesions of the dorsal tegmental noradrenergic projection. The LC lesions did not disrupt the acquisition of a running response for food reinforcement in an L-shaped runway, even though hippocampal-cortical norepinephrine (NE) was reduced to 29%. Greater telencephalic NE depletions (to 6% of control levels) produced by 6-OHDA also failed to disrupt the acquisition of this behavior or to impair the acquisition of a food-reinforced position habit in a T-maze. Neither locomotor activity nor habituation to a novel environment was affected by the 6-OHDA lesions. Rats with such lesions were, however, found to be significantly more distractible than were controls during the performance of a previously trained response. The hypothesis that telencephalic NE is of fundamental importance in learning was not supported. The data suggest that this system may participate in attentional mechanisms.

Enhanced noradrenergic activity in the amygdala contributes to hyperarousal in an animal model of PTSD

NARCIS (Netherlands)

Ronzoni, G.; Arco, A. Del; Mora, F.; Segovia, G.

2016-01-01

Increased activity of the noradrenergic system in the amygdala has been suggested to contribute to the hyperarousal symptoms associated with post-traumatic stress disorder (PTSD). However, only two studies have examined the content of noradrenaline or its metabolites in the amygdala of rats

Impaired cardiac uptake of meta-[123I]iodobenzylguanidine in Parkinson's disease with autonomic failure

International Nuclear Information System (INIS)

Braune, S.; Luecking, C.H.; Reinhardt, M.; Bathmann, J.; Krause, T.; Lehmann, M.

1998-01-01

Objective - To selectively investigate postganglionic sympathetic cardiac neurons in patients with Parkinson's disease and autonomic failure. Material and methods - Metaiodobenzylguanidine (MIBG) is a pharmacologically inactive analogue of noradrenaline, which is similarly metabolized in noradrenergic neurons. Therefore the uptake of radiolabelled MIBG represents not only the localization of postganglionic sympathetic neurons but also their functional integrity. Ten patients with Parkinson's disease and autonomic failure underwent standardized autonomic testing, assessment of catecholamine plasma levels and scintigraphy with [ 123 I]MIGB. Results - The cardiac uptake of MIBG, as demonstrated by the heart/mediastinum ratio, was significantly lower in patients in comparison with controls. Scintigraphy with MIBG allowed the selective in-vivo investigation of postganglionic sympathetic cardiac efferent in patients with autonomic failure, a procedure which was previously confined to post-mortem examination. Conclusion - These findings point to a relevant postganglionic pattern of involvement of the autonomic nervous system (ANS) in Parkinson's disease and autonomic failure. (au)

Localization of endogenous amyloid-β to the coeruleo-cortical pathway: consequences of noradrenergic depletion.

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Ross, Jennifer A; Reyes, Beverly A S; Thomas, Steven A; Van Bockstaele, Elisabeth J

2018-01-01

The locus coeruleus (LC)-norepinephrine (NE) system is an understudied circuit in the context of Alzheimer's disease (AD), and is thought to play an important role in neurodegenerative and neuropsychiatric diseases involving catecholamine neurotransmitters. Understanding the expression and distribution of the amyloid beta (Aβ) peptide, a primary component of AD, under basal conditions and under conditions of NE perturbation within the coeruleo-cortical pathway may be important for understanding its putative role in pathological states. Thus, the goal of this study is to define expression levels and the subcellular distribution of endogenous Aβ with respect to noradrenergic profiles in the rodent LC and medial prefrontal cortex (mPFC) and, further, to determine the functional relevance of NE in modulating endogenous Aβ 42 levels. We report that endogenous Aβ 42 is localized to tyrosine hydroxylase (TH) immunoreactive somatodendritic profiles of the LC and dopamine-β-hydroxylase (DβH) immunoreactive axon terminals of the infralimbic mPFC (ILmPFC). Male and female naïve rats have similar levels of amyloid precursor protein (APP) cleavage products demonstrated by western blot, as well as similar levels of endogenous Aβ 42 as determined by enzyme-linked immunosorbent assay. Two models of NE depletion, DSP-4 lesion and DβH knockout (KO) mice, were used to assess the functional relevance of NE on endogenous Aβ 42 levels. DSP-4 lesioned rats and DβH-KO mice show significantly lower levels of endogenous Aβ 42 . Noradrenergic depletion did not change APP-cleavage products resulting from β-secretase processing. Thus, resultant decreases in endogenous Aβ 42 may be due to decreased neuronal activity of noradrenergic neurons, or, by decreased stimulation of adrenergic receptors which are known to contribute to Aβ 42 production by enhancing γ-secretase processing under normal physiological conditions.

Noradrenergic Control of Odor Recognition in a Nonassociative Olfactory Learning Task in the Mouse

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Veyrac, Alexandra; Nguyen, Veronique; Marien, Marc; Didier, Anne; Jourdan, Francois

2007-01-01

The present study examined the influence of pharmacological modulations of the locus coeruleus noradrenergic system on odor recognition in the mouse. Mice exposed to a nonrewarded olfactory stimulation (training) were able to memorize this odor and to discriminate it from a new odor in a recall test performed 15 min later. At longer delays (30 or…

Noradrenergic activation of the basolateral amygdala modulates the consolidation of object-in-context recognition memory

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Areg eBarsegyan

2014-05-01

Full Text Available Noradrenergic activation of the basolateral complex of the amygdala (BLA is well known to enhance the consolidation of long-term memory of highly emotionally arousing training experiences. The present study investigated whether such noradrenergic activation of the BLA also influences the consolidation of object-in-context recognition memory, a low-arousing training task assessing episodic-like memory. Male Sprague–Dawley rats were exposed to two identical objects in one context for either 3 or 10 min, immediately followed by exposure to two other identical objects in a distinctly different context. Immediately after the training they received bilateral intra-BLA infusions of norepinephrine (0.3, 1.0 or 3.0 μg or the β-adrenoceptor antagonist propranolol (0.1, 0.3 or 1.0 μg. On the 24-h retention test, rats were placed back into one of the training contexts with one copy of each of the two training objects. Thus, although both objects were familiar, one of the objects had not previously been encountered in this particular test context. Hence, if the animal generated a long-term memory for the association between an object and its context, it would spend significantly more time exploring the object that was not previously experienced in this context. Saline-infused control rats exhibited poor 24-h retention when given 3 min of training and good retention when given 10 min of training. Norepinephrine administered after 3 min of object-in-context training induced a dose-dependent memory enhancement, whereas propranolol administered after 10 min of training produced memory impairment. These findings provide evidence that posttraining noradrenergic activation of the BLA also enhances the consolidation of memory of object-in-context recognition training, enabling accuracy of episodic-like memories.

Uptake and washout of I-123-MIBG in neuronal and non-neuronal sites in rat hearts. Relationship to renal clearance

International Nuclear Information System (INIS)

Arbab, A.S.; Koizumi, Kiyoshi; Araki, Tsutomu

1996-01-01

We investigated the uptake and washout of I-123-metaiodobenzylguanidine (MIBG) in neuronal (both intra-and extravesicular) and non-neuronal sites in the heart and its relationship to renal clearance. Acute renal failure was induced in rats by ligating the renal vessels, and the findings were compared with those of sham-operated rats. Each group consisted of control, reserpine-treated and 6-hydroxydopamine (6-OHDA)-treated subgroups. Rats were sacrificed at 10 minutes and 4 hours after injection of MIBG. MIBG activity was calculated in specimens of heart, spleen, lung and blood. At 10 minutes, no significant difference in MIBG uptake in the heart was observed among the subgroups or between sham-operated and renal failure rats despite a significantly higher blood MIBG activity in the latter. At 4 hours, however, the hearts of both reserpine-treated and 6-OHDA-treated rats showed significantly lower MIBG uptake than control rats. Furthermore, the hearts of renal failure rats showed higher MIBG uptake in the control and reserpine-treated rats than in the corresponding subgroups in sham-operated rats. Intra and extravesicular neuronal uptake of MIBG in the heart were estimated using control, reserpine-treated and 6-OHDA-treated rats. Vesicular uptake values were similar in both the sham-operated group (0.51% ID/g) and the renal failure group (0.44% ID/g). But extravesicular neuronal uptake values were quite different in the renal failure group (0.86% ID/g) and the sham-operated group (0.19% ID/g). In conclusion, uptake to and washout from extravesicular neuronal sites may depend on the concentration of MIBG in the blood or the state of renal clearance, but vesicular uptake may be independent of these factors. (author)

Tonic noradrenergic activity modulates explorative behavior and attentional set shifting: Evidence from pupillometry and gaze pattern analysis.

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Pajkossy, Péter; Szőllősi, Ágnes; Demeter, Gyula; Racsmány, Mihály

2017-12-01

A constant task for every living organism is to decide whether to exploit rewards associated with current behavior or to explore the environment for more rewarding options. Current empirical evidence indicates that exploitation is related to phasic whereas exploration is related to tonic firing mode of noradrenergic neurons in the locus coeruleus. In humans, this exploration-exploitation trade-off is subserved by the ability to flexibly switch attention between task-related and task-irrelevant information. Here, we investigated whether this function, called attentional set shifting, is related to exploration and tonic noradrenergic discharge. We measured pretrial baseline pupil dilation, proved to be strongly correlated with the activity of the locus coeruleus, while human participants took part in well-known tasks of attentional set shifting. Study 1 used the Wisconsin Card Sorting Task, whereas in Study 2, the Intra/Extradimensional Set Shifting Task was used. Both tasks require participants to choose between different compound stimuli based on feedback provided for their previous decisions. During the task, stimulus-reward contingencies change periodically, thus participants are repeatedly required to reassess which stimulus features are relevant (i.e., they shift their attentional set). Our results showed that baseline pupil diameter steadily decreased when the stimulus-reward contingencies were stable, whereas they suddenly increased when these contingencies changed. Analysis of looking patterns also confirmed the presence of exploratory behavior during attentional set shifting. Thus, our results suggest that tonic firing mode of noradrenergic neurons in the locus coeruleus is implicated in attentional set shifting, as it regulates the amount of exploration. © 2017 Society for Psychophysiological Research.

Role of diacylglycerol in adrenergic-stimulated sup 86 Rb uptake by proximal tubules

Energy Technology Data Exchange (ETDEWEB)

Baines, A.D.; Drangova, R.; Ho, P. (Univ. of Toronto, Ontario (Canada))

1990-05-01

We used rat proximal tubule fragments purified by Percoll centrifugation to examine the role of diacylglycerol (DAG) in noradrenergic-stimulated Na+ reabsorption. Tubular DAG concentration and ouabain-inhibitable 86Rb uptake increased within 30 s after adding norepinephrine (NE) and remained elevated for at least 5 min. NE (1 microM) increased DAG content 17% and ouabain-inhibitable 86Rb uptake 23%. Cirazoline-stimulated 86Rb uptake was not inhibited by BaCl, quinidine, or bumetanide (1-10 microM) or by the omission of HCO3- or Cl- from the medium, but it was completely inhibited by ouabain and furosemide. Oleoyl-acetyl glycerol, L-alpha-1,2-dioctanoylglycerol, and L-alpha-1,2-dioleoylglycerol (DOG) increased total 86Rb uptake 8-11%. 12-O-tetradecanoylphorbol-13-acetate (TPA) (5 nM) increased uptake by only 4%. Staurosporine at 5 nM inhibited DOG stimulation completely, whereas 50 nM staurosporine was required to inhibit NE stimulation completely. Sphingosine inhibited DOG stimulation by 66% but did not inhibit NE stimulation. Amiloride (1 mM) completely blocked DOG stimulation. Monensin increased 86Rb uptake 31% and completely blocked the DOG effect but reduced the NE effect by only 26% (P = 0.08). In tubules from salt-loaded rats, NE did not increase DAG concentration, but NE-stimulated 86Rb uptake was reduced by only 23% (P = 0.15). Thus DAG released by NE may stimulate Na+ entry through Na(+)-H+ exchange. NE predominantly stimulates Na(+)-K(+)-adenosinetriphosphatase (ATPase) by activating a protein kinase that is insensitive to DAG and TPA and is inhibited by staurosporine but not by sphingosine. NE may also stimulate K+ efflux through a BaCl-insensitive K+ channel that is inhibited by millimolar furosemide.

Generation of Two Noradrenergic-Specific Dopamine-Beta-Hydroxylase-FLPo Knock-In Mice Using CRISPR/Cas9-Mediated Targeting in Embryonic Stem Cells.

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Jenny J Sun

Full Text Available CRISPR/Cas9 mediated DNA double strand cutting is emerging as a powerful approach to increase rates of homologous recombination of large targeting vectors, but the optimization of parameters, equipment and expertise required remain barriers to successful mouse generation by single-step zygote injection. Here, we sought to apply CRISPR/Cas9 methods to traditional embryonic stem (ES cell targeting followed by blastocyst injection to overcome the common issues of difficult vector construction and low targeting efficiency. To facilitate the study of noradrenergic function, which is implicated in myriad behavioral and physiological processes, we generated two different mouse lines that express FLPo recombinase under control of the noradrenergic-specific Dopamine-Beta-Hydroxylase (DBH gene. We found that by co-electroporating a circular vector expressing Cas9 and a locus-specific sgRNA, we could target FLPo to the DBH locus in ES cells with shortened 1 kb homology arms. Two different sites in the DBH gene were targeted; the translational start codon with 6-8% targeting efficiency, and the translational stop codon with 75% targeting efficiency. Using this approach, we established two mouse lines with DBH-specific expression of FLPo in brainstem catecholaminergic populations that are publically available on MMRRC (MMRRC_041575-UCD and MMRRC_041577-UCD. Altogether, this study supports simplified, high-efficiency Cas9/CRISPR-mediated targeting in embryonic stem cells for production of knock-in mouse lines in a wider variety of contexts than zygote injection alone.

Structure activity correlations in the inhibition of brain synaptosomal 3H-norepinephrine uptake by phenethylamine analogs. The role of α-alkyl side chain and methoxyl ring substitutions

International Nuclear Information System (INIS)

Makriyannis, A.; Bowerman, D.; Sze, P.Y.; Fournier, D.; Jong, A.P. de

1982-01-01

α-Ethylphenethylamine proved to be a weaker inhibitor of rat brain synaptosomal [ 3 H]norepinephrine ([ 3 H]NE) uptake than amphetamine, while 2-amino-tetralin and 2-amino-1,2-dihydronaphtalene, compounds in which the α-side chain ethyl group is tied to the aromatic ring have a similar inhibiting potency as amphetamine. Hallucinogenic polymethoxy substituted phenethylamine analogs have very low inhibitory potencies indicating that inhibition of NE-reuptake in brain noradrenergic neurons is not associated with the drug-induced hallucinogenic syndrome. (Auth.)

Selective labeling of serotonin uptake sites in rat brain by [3H]citalopram contrasted to labeling of multiple sites by [3H]imipramine

International Nuclear Information System (INIS)

D'Amato, R.J.; Largent, B.L.; Snowman, A.M.; Snyder, S.H.

1987-01-01

Citalopram is a potent and selective inhibitor of neuronal serotonin uptake. In rat brain membranes [ 3 H]citalopram demonstrates saturable and reversible binding with a KD of 0.8 nM and a maximal number of binding sites (Bmax) of 570 fmol/mg of protein. The drug specificity for [ 3 H]citalopram binding and synaptosomal serotonin uptake are closely correlated. Inhibition of [ 3 H]citalopram binding by both serotonin and imipramine is consistent with a competitive interaction in both equilibrium and kinetic analyses. The autoradiographic pattern of [ 3 H]citalopram binding sites closely resembles the distribution of serotonin. By contrast, detailed equilibrium-saturation analysis of [ 3 H]imipramine binding reveals two binding components, i.e., high affinity (KD = 9 nM, Bmax = 420 fmol/mg of protein) and low affinity (KD = 553 nM, Bmax = 8560 fmol/mg of protein) sites. Specific [ 3 H]imipramine binding, defined as the binding inhibited by 100 microM desipramine, is displaced only partially by serotonin. Various studies reveal that the serotonin-sensitive portion of binding corresponds to the high affinity sites of [ 3 H]imipramine binding whereas the serotonin-insensitive binding corresponds to the low affinity sites. Lesioning of serotonin neurons with p-chloroamphetamine causes a large decrease in [ 3 H]citalopram and serotonin-sensitive [ 3 H]imipramine binding with only a small effect on serotonin-insensitive [ 3 H]imipramine binding. The dissociation rate of [ 3 H]imipramine or [ 3 H]citalopram is not altered by citalopram, imipramine or serotonin up to concentrations of 10 microM. The regional distribution of serotonin sensitive [ 3 H]imipramine high affinity binding sites closely resembles that of [ 3 H]citalopram binding

Noradrenergic stimulation modulates activation of extinction-related brain regions and enhances contextual extinction learning without affecting renewal

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Silke eLissek

2015-02-01

Full Text Available Renewal in extinction learning describes the recovery of an extinguished response if the extinction context differs from the context present during acquisition and recall. Attention may have a role in contextual modulation of behavior and contribute to the renewal effect, while noradrenaline is involved in attentional processing. In this functional magnetic resonance imaging (fMRI study we investigated the role of the noradrenergic system for behavioral and brain activation correlates of contextual extinction and renewal, with a particular focus upon hippocampus and ventromedial PFC, which have crucial roles in processing of renewal. Healthy human volunteers received a single dose of the NA reuptake inhibitor atomoxetine prior to extinction learning. During extinction of previously acquired cue-outcome associations, cues were presented in a novel context (ABA or in the acquisition context (AAA. In recall, all cues were again presented in the acquisition context. Atomoxetine participants (ATO showed significantly faster extinction compared to placebo (PLAC. However, atomoxetine did not affect renewal. Hippocampal activation was higher in ATO during extinction and recall, as was ventromedial PFC activation, except for ABA recall. Moreover, ATO showed stronger recruitment of insula, anterior cingulate, and dorsolateral/orbitofrontal PFC. Across groups, cingulate, hippocampus and vmPFC activity during ABA extinction correlated with recall performance, suggesting high relevance of these regions for processing the renewal effect. In summary, the noradrenergic system appears to be involved in the modification of established associations during extinction learning and thus has a role in behavioral flexibility. The assignment of an association to a context and the subsequent decision on an adequate response, however, presumably operate largely independently of noradrenergic mechanisms.

Thyroid Scan and Uptake

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ...

CHOLINERGIC AND NORADRENERGIC MODULATION OF LONG-TERM EXPLICIT MEMORY ARE ALTERED BY CHRONIC LOW-LEVEL LEAD EXPOSURE. (U915393)

Science.gov (United States)

Recent evidence suggests that septohippocampal cholinergic activity is suppressed in rats exposed to low levels of lead (Pb). As a result, noradrenergic activity may be elevated due to compensatory sympathetic sprouting. Therefore, the goals of this study were to (a) determine...

Noradrenergic Activation of the Basolateral Amygdala Enhances Object Recognition Memory and Induces Chromatin Remodeling in the Insular Cortex

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Hassiba eBeldjoud

2015-04-01

Full Text Available It is well established that arousal-induced memory enhancement requires noradrenergic activation of the basolateral complex of the amygdala (BLA and modulatory influences on information storage processes in its many target regions. While this concept is well accepted, the molecular basis of such BLA effects on neural plasticity changes within other brain regions remains to be elucidated. The present study investigated whether noradrenergic activation of the BLA after object recognition training induces chromatin remodeling through histone post-translational modifications in the insular cortex (IC, a brain region that is importantly involved in object recognition memory. Male Sprague–Dawley rats were trained on an object recognition task, followed immediately by bilateral microinfusions of norepinephrine (1.0 µg or saline administered into the BLA. Saline-treated control rats exhibited poor 24-h retention, whereas norepinephrine treatment induced robust 24-h object recognition memory. Most importantly, this memory-enhancing dose of norepinephrine induced a global reduction in the acetylation levels of histone H3 at lysine 14, H2B and H4 in the IC 1 h later, whereas it had no effect on the phosphorylation of histone H3 at serine 10 or tri-methylation of histone H3 at lysine 27. Norepinephrine administered into the BLA of non-trained control rats did not induce any changes in the histone marks investigated in this study. These findings indicate that noradrenergic activation of the BLA induces training-specific effects on chromatin remodeling mechanisms, and presumably gene transcription, in its target regions, which may contribute to the understanding of the molecular mechanisms of stress and emotional arousal effects on memory consolidation.

Both a Nicotinic Single Nucleotide Polymorphism (SNP) and a Noradrenergic SNP Modulate Working Memory Performance when Attention Is Manipulated

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Greenwood, Pamela M.; Sundararajan, Ramya; Lin, Ming-Kuan; Kumar, Reshma; Fryxell, Karl J.; Parasuraman, Raja

2009-01-01

We investigated the relation between the two systems of visuospatial attention and working memory by examining the effect of normal variation in cholinergic and noradrenergic genes on working memory performance under attentional manipulation. We previously reported that working memory for location was impaired following large location precues,…

Ilex paraguariensis Promotes Orofacial Pain Relief After Formalin Injection: Involvement of Noradrenergic Pathway.

Science.gov (United States)

de Carvalho, Eudislaine Fonseca; de Oliveira, Simone Kobe; Nardi, Viviane Koepp; Gelinski, Tathiana Carla; Bortoluzzi, Marcelo Carlos; Maraschin, Marcelo; Nardi, Geisson Marcos

2016-03-01

Drinking mate or chimarrão, a hot infusion of Ilex paraguariensis (ILEX) leaves, is a common habit in Southern South America that has a social and almost ritualistic role. It has been used as a stimulant beverage in South America and analgesic in regions of Argentina for treatment of headache and others painful inflammatory conditions such as arthritis and rheumatism. The aim of this study was to evaluate the pharmacological activity of I. paraguariensis infusion (ILEX) on orofacial nociception model induced by formalin, and study its mechanism of action. The analgesic effect of ILEX was assessed through writhing test, paw formalin test, paw edema induced by carrageenan, and orofacial pain induced by formalin. To study the action mechanism of ILEX, opioidergic, dopaminergic, nitrergic, and adrenergic pathways were investigated. The high-performance liquid chromatography analysis of ILEX infusion revealed caffeine and theobromine. The treatment with ILEX reduced the number of writhing. However, it was effective neither in the formalin paw test nor in the paw edema induced by carrageenan. Different from formalin paw test, ILEX was able to reduce the orofacial reactivity to formalin in 31.8% (70.4 ± 2.5 s; first phase), and 20% (127.3 ± 18.9 s; second phase). The analgesic effect of ILEX results from the modulation of noradrenergic pathways since prazosin (α1-adrenoceptor antagonist, 0.15 mg/kg; intraperitoneal) reversed the analgesic effect of ILEX. The present report demonstrates that analgesic effect of ILEX in orofacial formalin test is due mainly to modulation of noradrenergic pathways. Ilex paraguariensis (ILEX) has been used as a stimulant beverage in South America and analgesic in regions of Argentina for the treatment of headache and others painful inflammatory conditions such arthritis and rheumatism.The aim of this study was to evaluate the pharmacological activity of ILEX on orofacial nociception model induced by formalin, and study its mechanism of

Dopamine modulates male sexual behavior in Japanese quail in part via actions on noradrenergic receptors.

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Cornil, Charlotte A; Dejace, Christel; Ball, Gregory F; Balthazart, Jacques

2005-08-30

In rats, dopamine (DA) facilitates male sexual behavior through its combined action on D1- and D2-like receptors, in the medial preoptic area (MPOA) as well as other brain areas. In Japanese quail, systemic injections of dopaminergic drugs suggested a similar pharmacology but central injections have never been performed. Recent electrophysiological experiments demonstrated that DA effects in the MPOA of quail are mediated mainly through the activation of alpha2-noradrenergic receptors. Previous studies of DA action on behavior used specific dopaminergic agonists/antagonists and therefore unintentionally avoided the potential cross-reaction with alpha2-receptors. The present study was thus designed to investigate directly the effects of DA on male sexual behavior and to test whether the interaction of DA with heterologous receptors affects this behavior. Intracerebroventricular (i.c.v.) injection of DA or NE inhibited copulation in a dose-dependent manner. Systemic injections of yohimbine, an alpha2-noradrenergic antagonist, modulated copulation in a bimodal manner depending on the dose injected. Interestingly, a behaviorally ineffective dose of yohimbine markedly reduced the inhibitory effects of DA when injected 15min before. Together, these results show for the first time that i.c.v. injections of DA itself inhibit male sexual behavior in quail and suggest that the interaction of DA with alpha2-receptors has behavioral significance.

A computational psychiatry approach identifies how alpha-2a noradrenergic agonist guanfacine affects feature-based reinforcement learning in the macaque

NARCIS (Netherlands)

Hassani, S.A.; Oemisch, M.; Balcarras, M.; Westendorff, S.; Ardid, S.; van der Meer, M.A.; Tiesinga, P.H.E.; Womelsdorf, T.

2017-01-01

Noradrenaline is believed to support cognitive flexibility through the alpha 2A noradrenergic receptor (a2A-NAR) acting in prefrontal cortex. Enhanced flexibility has been inferred from improved working memory with the a2A-NA agonist Guanfacine. But it has been unclear whether Guanfacine improves

Short-term serotonergic but not noradrenergic antidepressant administration reduces attentional vigilance to threat in healthy volunteers

OpenAIRE

Murphy, Susannah E; Yiend, Jenny; Lester, Kathryn J; Cowen, Philip J; Harmer, Catherine J

2009-01-01

Anxiety is associated with threat-related biases in information processing such as heightened attentional vigilance to potential threat. Such biases are an important focus of psychological treatments for anxiety disorders. Selective serotonin reuptake inhibitors (SSRIs) are effective in the treatment of a range of anxiety disorders. The aim of this study was to assess the effect of an SSRI on the processing of threat in healthy volunteers. A selective noradrenergic reuptake inhibitor (SNRI), ...

Cold-induced vasoconstriction at forearm and hand skin sites: the effect of age.

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Kingma, B R M; Frijns, A J H; Saris, W H M; van Steenhoven, A A; van Marken Lichtenbelt, W D

2010-07-01

During mild cold exposure, elderly are at risk of hypothermia. In humans, glabrous skin at the hands is well adapted as a heat exchanger. Evidence exists that elderly show equal vasoconstriction due to local cooling at the ventral forearm, yet no age effects on vasoconstriction at hand skin have been studied. Here, we tested the hypotheses that at hand sites (a) elderly show equal vasoconstriction due to local cooling and (b) elderly show reduced response to noradrenergic stimuli. Skin perfusion and mean arterial pressure were measured in 16 young adults (Y: 18-28 years) and 16 elderly (E: 68-78 years). To study the effect of local vasoconstriction mechanisms local sympathetic nerve terminals were blocked by bretylium (BR). Baseline local skin temperature was clamped at 33 degrees C. Next, local temperature was reduced to 24 degrees C. After 15 min of local cooling, noradrenaline (NA) was administered to study the effect of neural vasoconstriction mechanisms. No significant age effect was observed in vasoconstriction due to local cooling at BR sites. After NA, vasoconstriction at the forearm showed a significant age effect; however, no significant age effect was found at the hand sites. [Change in CVC (% from baseline): Forearm Y: -76 +/- 3 vs. E: -60 +/- 5 (P forearm, elderly did not show a blunted response to local cooling and noradrenaline at hand skin sites. This indicates that at hand skin the noradrenergic mechanism of vasoconstriction is maintained with age.

Water uptake by two river red gum ( Eucalyptus camaldulensis) clones in a discharge site plantation in the Western Australian wheatbelt

Science.gov (United States)

Marshall, John K.; Morgan, Anne L.; Akilan, Kandia; Farrell, Richard C. C.; Bell, David T.

1997-12-01

The heat-pulse technique was used to estimate year-long water uptake in a discharge zone plantation of 9-year-old clonal Eucalyptus camaldulensis Dehnh. near Wubin, Western Australia. Water uptake matched rainfall closely during weter months but exceeded rainfall as the dry season progressed. Average annual water uptake (1148 mm) exceeded rainfall (432 mm) by about 2.7 fold and approached 56% of pan evaporation for the area. The data suggest that at least 37% (i.e. ( {1}/{2.7}) × 100 ) of the lower catchment discharge zone should be planted to prevent the rise of groundwater. Water uptake varied with soil environment, season and genotype. Upslope trees used more water than did downslope trees. Water uptake was higher in E. camaldulensis clone M80 than in clone M66 until late spring. The difference reversed as summer progressed. Both clones, however, have the potential to dry out the landscape when potential evapotranspiration exceeds rainfall. This variation in water uptake within the species indicates the potential for manipulating plantation uptake by matching tree characteristics to site characteristics. Controlled experiments on the heat-pulse technique indicated accuracy errors of approximately 10%. This, combined with the ability to obtain long-term, continuous data and the superior logistics of use of the heat-pulse technique, suggests that results obtained by it would be much more reliable than those achieved by the ventilated chamber technique.

Noradrenergic Activation of Hypoglossal Nucleus Modulates the Central Regulation of Genioglossus in Chronic Intermittent Hypoxic Rats

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Wei Wang

2017-05-01

Full Text Available Neuromuscular compensation of the genioglossus muscle can be induced by chronic intermittent hypoxia (CIH in obstructive sleep apnea to maintain upper airway stability. Noradrenergic activation of hypoglossal nucleus plays a critical role in the central control of the genioglossus. However, it remains unknown whether norepinephrine takes part in the central regulation of the genioglossus during CIH. Adult male Wistar rats (n = 32 were studied to explore the influence of noradrenergic activation of hypoglossal nucleus on the central control of the genioglossus at different stages of CIH. The rats were divided into four groups: normal control or normoxic (NO group, CIH group, CIH + normal saline (NS group, and CIH + prazosin (PZ, α1-adrenergic antagonist group. PZ (0.2 mM, 60 nl and NS (0.9%, 60 nl were microinjected into the hypoglossal nucleus. The responses of the genioglossus corticomotor area to transcranial magnetic stimulation (TMS were recorded on the 1st, 7th, 14th, and 21st day of CIH. The CIH group showed significantly shorter TMS latencies on days 1, 7, and 14 (3.85 ± 0.37 vs. 4.58 ± 0.42, 3.93 ± 0.17 vs. 4.49 ± 0.55, 3.79 ± 0.38 vs. 4.39 ± 0.30 ms, P < 0.05, and higher TMS amplitudes on day 1 (2.74 ± 0.87 vs. 1.60 ± 0.52 mV, P < 0.05 of CIH than the NO group. Compared to the CIH + NS group, the CIH + PZ group showed decreased TMS responses (longer latencies and lower amplitudes only on the 14th day of CIH (3.99 ± 0.28 vs. 4.61 ± 0.48 ms, 2.51 ± 0.67 vs. 1.18 ± 0.62 mV, P < 0.05. These results indicated that noradrenergic activation of the hypoglossal nucleus played a role in the central compensation of genioglossus through α1-adrenoceptor on the 14th day of CIH.

3,4-Methylenedioxymethamphetamine and 3,4-methylenedioxyamphetamine destroy serotonin terminals in rat brain: quantification of neurodegeneration by measurement of [3H]paroxetine-labeled serotonin uptake sites

International Nuclear Information System (INIS)

Battaglia, G.; Yeh, S.Y.; O'Hearn, E.; Molliver, M.E.; Kuhar, M.J.; De Souza, E.B.

1987-01-01

This study examines the effects of repeated systemic administration (20 mg/kg s.c., twice daily for 4 days) of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) on levels of brain monoamines, their metabolites and on the density of monoamine uptake sites in various regions of rat brain. Marked reductions (30-60%) in the concentration of 5-hydroxyindoleacetic acid were observed in cerebral cortex, hippocampus, striatum, hypothalamus and midbrain at 2 weeks after a 4-day treatment regimen of MDMA or MDA; less consistent reductions in serotonin (5-HT) content were observed in these brain regions. In addition, both MDMA and MDA caused comparable and substantial reductions (50-75%) in the density of [ 3 H]paroxetine-labeled 5-HT uptake sites in all brain regions examined. In contrast, neither MDMA nor MDA caused any widespread or long-term changes in the content of the catecholaminergic markers (i.e., norepinephrine, dopamine, 3,4 dihydroxyphenylacetic acid and homovanillic acid) or in the number of [ 3 H]mazindol-labeled norepinephrine or dopamine uptake sites in the brain regions examined. These data demonstrate that MDMA and MDA cause long-lasting neurotoxic effects with respect to both the functional and structural integrity of serotonergic neurons in brain. Furthermore, our measurement of reductions in the density of 5-HT uptake sites provides a means for quantification of the neurodegenerative effects of MDMA and MDA on presynaptic 5-HT terminals

Peripheral markers of serotonergic and noradrenergic function in post-pubertal, caucasian males with autistic disorder.

Science.gov (United States)

Croonenberghs, J; Delmeire, L; Verkerk, R; Lin, A H; Meskal, A; Neels, H; Van der Planken, M; Scharpe, S; Deboutte, D; Pison, G; Maes, M

2000-03-01

Some studies have suggested that disorders in the peripheral and central metabolism of serotonin (5-HT) and noradrenaline may play a role in the pathophysiology of autistic disorder. This study examines serotonergic and noradrenergic markers in a study group of 13 male, post-pubertal, caucasian autistic patients (age 12-18 y; I.Q. > 55) and 13 matched volunteers. [3H]-paroxetine binding Kd values were significantly higher in patients with autism than in healthy volunteers. Plasma concentrations of tryptophan, the precursor of 5-HT, were significantly lower in autistic patients than in healthy volunteers. There were no significant differences between autistic and normal children in the serum concentrations of 5-HT, or the 24-hr urinary excretion of 5-hydroxy-indoleacetic acid (5-HIAA), adrenaline, noradrenaline, and dopamine. There were no significant differences in [3H]-rauwolscine binding Bmax or Kd values, or in the serum concentrations of tyrosine, the precursor of noradrenaline, between both study groups. There were highly significant positive correlations between age and 24-hr urinary excretion of 5-HIAA and serum tryptophan. The results suggest that: 1) serotonergic disturbances, such as defects in the 5-HT transporter system and lowered plasma tryptophan, may play a role in the pathophysiology of autism; 2) autism is not associated with alterations in the noradrenergic system; and 3) the metabolism of serotonin in humans undergoes significant changes between the ages of 12 and 18 years.

The relevance of parametric U-uptake models in ESR age calculations

International Nuclear Information System (INIS)

Gruen, Rainer

2009-01-01

In the ESR dating three basic parametric U-uptake models have been applied for dating teeth: early U-uptake (EU: closed system), linear U-uptake (LU) and recent U-uptake (RU, it is assumed that the dose rate contribution of U in the dental tissues is zero). In many ESR dating publications it is still assumed that samples comply with one or the other parametric U-uptake model calculation or that their correct age lies somewhere between EU and LU. Observations of the spatial distribution of uranium in dental tissues show that it is difficult to predict any relationships between the relative uptake in the dental tissues. Combined U-series/ESR age estimates can give insights into the actual U-uptake. An evaluation of published data shows that for cave sites, a significant number of results fall outside the EU and LU bracket, while for open air sites, the majority of data are outside this bracket, particularly showing greatly delayed U-uptake. This may be due to changes in the hydrological system, leading to erosion which exposes the open air site. U-leaching has also been observed on samples from open air sites, in which case any reasonable age calculation is impossible.

Noradrenergic mechanisms and high blood pressure maintenance in genetic hypertension: The role of Gi proteins and voltage-dependent calcium channels

Czech Academy of Sciences Publication Activity Database

Zicha, Josef; Pintérová, Mária; Líšková, Silvia; Dobešová, Zdenka; Kuneš, Jaroslav

2007-01-01

Roč. 29, č. 4 (2007), s. 229-229 ISSN 1064-1963. [International symposium on SHR /12./. 20.10.2006-21.10.2006, Kyoto] R&D Projects: GA MZd(CZ) NR7786 Institutional research plan: CEZ:AV0Z50110509 Keywords : genetic hypertension * noradrenergic mechanisms * Gi proteins * voltage-dependent calcium channels Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

Comparison between AOT40 and ozone uptake in forest trees of different species, age and site conditions

Science.gov (United States)

Matyssek, R.; Wieser, G.; Nunn, A. J.; Kozovits, A. R.; Reiter, I. M.; Heerdt, C.; Winkler, J. B.; Baumgarten, M.; Häberle, K.-H.; Grams, T. E. E.; Werner, H.; Fabian, P.; Havranek, W. M.

The current AOT40 concept for inferring risks in forest trees by ozone (O 3) injury is based on an accumulated external O 3 exposure rather than an internal O 3 dose or uptake rate. AOT40 assumes O 3 concentrations below 40 nl l -1 and night-time exposure to be negligible. Hence, this concept is rather inconsistent with observed forest conditions. In contrast, the flux concept of cumulative O 3 uptake (CU) into the leaves has the potential of reflecting a physiologically meaningful internal O 3 dose experienced by trees. In this paper, we relate AOT40 to cumulative O 3 uptake into European beech ( Fagus sylvatica), Norway spruce ( Picea abies), European larch ( Larix decidua) and cembran pine ( Pinus cembra) trees differing in size, age and site conditions. We demonstrate that the flux concept can be extended to the tree and the stand level, making use of sap flow measurements through tree trunks. Although in both seedlings and adult trees AOT40 may show some linearity in correlations with average CU, the latter varies, at given AOT40, by 25±11% within and between species. This is because O 3 flux is primarily influenced by stomatal aperture, the latter being affected by climate, canopy position, leaf and tree age while varying between species. In particular, if weighed by detoxification capacity, we suggest, therefore, O 3 uptake related air quality indices to be promoted towards ecologically meaningful standards in forest protection, overcoming the shortcomings of exposure concepts. As O 3 injury results from the balance between O 3 uptake and detoxification in the leaf mesophyll, we conclude the flux concept in combination with measures of biochemical defence to have the capacity for predicting tree response to O 3 stress.

Does Growth Impairment Underlie the Adverse Effects of Dexamethasone on Development of Noradrenergic Systems?

Science.gov (United States)

Slotkin, Theodore A; Ko, Ashley; Seidler, Frederic J

2018-06-20

Glucocorticoids are given in preterm labor to prevent respiratory distress but these agents evoke neurobehavioral deficits in association with reduced brain region volumes. To determine whether the neurodevelopmental effects are distinct from growth impairment, we gave developing rats dexamethasone at doses below or within the therapeutic range (0.05, 0.2 or 0.8 mg/kg) at different stages: gestational days (GD) 17-19, postnatal days (PN) 1-3 or PN7-9. In adolescence and adulthood, we assessed the impact on noradrenergic systems in multiple brain regions, comparing the effects to those on somatic growth or on brain region growth. Somatic growth was reduced with exposure in all three stages, with greater sensitivity for the postnatal regimens; brain region growth was impaired to a lesser extent. Norepinephrine content and concentration were reduced depending on the treatment regimen, with a rank order of deficits of PN7-9 > PN1-3 > GD17-19. However, brain growth impairment did not parallel reduced norepinephrine content in magnitude, dose threshold, sex or regional selectivity, or temporal pattern, and even when corrected for reduced brain region weights (norepinephrine per g tissue), the dexamethasone-exposed animals showed subnormal values. Regression analysis showed that somatic growth impairment accounted for an insubstantial amount of the reduction in norepinephrine content, and brain growth impairment accounted for only 12%, whereas specific effects on norepinephrine accounted for most of the effect. The adverse effects of dexamethasone on noradrenergic system development are not simply related to impaired somatic or brain region growth, but rather include specific targeting of neurodifferentiation. Copyright © 2018. Published by Elsevier B.V.

Coupling nutrient uptake and energy flow in headwater streams

Energy Technology Data Exchange (ETDEWEB)

Mulholland, Patrick J [ORNL; Fellows, Christine [Griffith University, Nathan, Queensland, Australia; Valett, H. Maurice [Virginia Polytechnic Institute and State University (Virginia Tech); Dahm, Cliff [University of New Mexico, Albuquerque; Thomas, Steve [University of Nebraska

2006-08-01

Nutrient cycling and energy flow in ecosystems are tightly linked through the metabolic processes of organisms. Greater uptake of inorganic nutrients is expected to be associated with higher rates of metabolism [gross primary production (GPP) and respiration (R)], due to assimilatory demand of both autotrophs and heterotrophs. However, relationships between uptake and metabolism should vary with the relative contribution of autochthonous and allochthonous sources of organic matter. To investigate the relationship between metabolism and nutrient uptake, we used whole-stream and benthic chamber methods to measure rates of nitrate-nitrogen (NO{sub 3}-N) uptake and metabolism in four headwater streams chosen to span a range of light availability and therefore differing rates of GPP and contributions of autochthonous carbon. We coupled whole-stream metabolism with measures of NO{sub 3}-N uptake conducted repeatedly over the same stream reach during both day and night, as well as incubating benthic sediments under both light and dark conditions. NO{sub 3}-N uptake was generally greater in daylight compared to dark conditions, and although day-night differences in whole-stream uptake were not significant, light-dark differences in benthic chambers were significant at three of the four sites. Estimates of N demand indicated that assimilation by photoautotrophs could account for the majority of NO{sub 3}-N uptake at the two sites with relatively open canopies. Contrary to expectations, photoautotrophs contributed substantially to NO{sub 3}-N uptake even at the two closed-canopy sites, which had low values of GPP/R and relied heavily on allochthonous carbon to fuel R.

Inferior frontal gyrus preserves working memory and emotional learning under conditions of impaired noradrenergic signaling

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Benjamin eBecker

2013-12-01

Full Text Available Compensation has been widely applied to explain neuroimaging findings in neuropsychiatric patients. Functional compensation is often invoked when patients display equal performance and increased neural activity in comparison to healthy controls. According to the compensatory hypothesis increased activity allows the brain to maintain cognitive performance despite underlying neuropathological changes. Due to methodological and pathology-related issues, however, the functional relevance of the increased activity and the specific brain regions involved in the compensatory response remain unclear. An experimental approach that allows a transient induction of compensatory responses in the healthy brain could help to overcome these issues. To this end we used the nonselective beta-blocker propranolol to pharmacologically induce sub-optimal noradrenergic signaling in healthy participants. In two independent fMRI experiments participants received either placebo or propranolol before they underwent a cognitive challenge (experiment 1: working memory; experiment 2: emotional learning: Pavlovian fear conditioning. In experiment 1 propranolol had no effects on working memory performance, but evoked stronger activity in the left inferior frontal gyrus (IFG. In experiment 2 propranolol produced no effects on emotional memory formation, but evoked stronger activity in the right IFG. The present finding that sub-optimal beta-adrenergic signaling did not disrupt performance and concomitantly increased IFG activity is consistent with, and extends, current perspectives on functional compensation. Together, our findings suggest that under conditions of impaired noradrenergic signaling, heightened activity in brain regions located within the cognitive control network, particularly the IFG, may reflect compensatory operations subserving the maintenance of behavioral performance.

The selective neurotoxin DSP-4 impairs the noradrenergic projections from the locus coeruleus to the inferior colliculus in rats.

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Sebastián eHormigo

2012-06-01

Full Text Available The inferior colliculus (IC and the locus coeruleus (LC are two midbrain nuclei that integrate multimodal information and play a major role in novelty detection to elicit an orienting response. Despite the reciprocal connections between these two structures, the projection pattern and target areas of the LC within the subdivisions of the rat IC are still unknown. Here, we used tract-tracing approaches combined with immunohistochemistry, densitometry and confocal microscopy analysis to describe a projection from the LC to the IC. Biotinylated dextran amine (BDA injections into the LC showed that the LC-IC projection is mainly ipsilateral (90% and reaches, to a major extent, the dorsal and lateral part of the IC and the intercollicular commissure. Additionally, some LC fibers extend into the central nucleus of the IC. The neurochemical nature of this projection is noradrenergic, given that tyrosine hydroxylase (TH and dopamine beta hydroxylase (DBH colocalize with the BDA-labeled fibers from the LC. To determine the total field of the LC innervations in the IC, we destroyed the LC neurons and fibers using a highly selective neurotoxin, DSP-4, and then studied the distribution and density of TH- and DBH-immunolabeled axons in the IC. In the DSP-4 treated animals, the number of axonal fibers immunolabeled for TH and DBH were deeply decreased throughout the entire rostrocaudal extent of the IC and its subdivisions compared to controls. Our densitometry results showed that the IC receives up to 97% of its noradrenergic innervations from the LC neurons and only 3% from non-coeruleus neurons. Our results also indicate that TH immunoreactivity in the IC was less impaired than the immunoreactivity for DBH after DSP-4 administration. This is consistent with the existence of an important dopaminergic projection from the substantia nigra to the IC. In conclusion, our study demonstrates and quantifies the noradrenergic projection from the LC to the IC and its

Too much of a good thing: blocking noradrenergic facilitation in medial prefrontal cortex prevents the detrimental effects of chronic stress on cognition.

Science.gov (United States)

Jett, Julianne D; Morilak, David A

2013-03-01

Cognitive impairments associated with dysfunction of the medial prefrontal cortex (mPFC) are prominent in stress-related psychiatric disorders. We have shown that enhancing noradrenergic tone acutely in the rat mPFC facilitated extra-dimensional (ED) set-shifting on the attentional set-shifting test (AST), whereas chronic unpredictable stress (CUS) impaired ED. In this study, we tested the hypothesis that the acute facilitatory effect of norepinephrine (NE) in mPFC becomes detrimental when activated repeatedly during CUS. Using microdialysis, we showed that the release of NE evoked in mPFC by acute stress was unchanged at the end of CUS treatment. Thus, to then determine if repeated elicitation of this NE activity in mPFC during CUS may have contributed to the ED deficit, we infused a cocktail of α(1)-, β(1)-, and β(2)-adrenergic receptor antagonists into the mPFC prior to each CUS session, then tested animals drug free on the AST. Antagonist treatment prevented the CUS-induced ED deficit, suggesting that NE signaling during CUS compromised mPFC function. We confirmed that this was not attributable to sensitization of adrenergic receptor function following chronic antagonist treatment, by administering an additional microinjection into the mPFC immediately prior to ED testing. Acute antagonist treatment did not reverse the beneficial effects of chronic drug treatment during CUS, nor have any effect on baseline ED performance in chronic vehicle controls. Thus, we conclude that blockade of noradrenergic receptors in mPFC protected against the detrimental cognitive effects of CUS, and that repeated elicitation of noradrenergic facilitatory activity is one mechanism by which chronic stress may promote mPFC cognitive dysfunction.

A study of the uptake of chloroquine in malaria-infected erythrocytes. High and low affinity uptake and the influence of glucose and its analogues.

Science.gov (United States)

Diribe, C O; Warhurst, D C

1985-09-01

A study of concentration- and substrate-dependence of chloroquine uptake has been carried out on mouse erythrocytes infected with the chloroquine-sensitive NK65 and the chloroquine-resistant RC strains of Plasmodium berghei. The presence of drug binding sites of high and low affinity in such strains of P. berghei was confirmed. High affinity uptake sites in cells parasitized with chloroquine-sensitive and chloroquine-resistant parasites have similar characteristics, but in the sensitive strain the major component of chloroquine-uptake is at high affinity and dependent on the availability of ATP whilst in the resistant strain the major component of uptake is at low affinity and independent of energy. An absolute increase in the quantity of the low affinity site in erythrocytes parasitized with chloroquine-resistant P. berghei was noted, which may be related to an increase in quantity of parasite membrane.

Autoradiographic analysis of alpha 1-noradrenergic receptors in the human brain postmortem. Effect of suicide

International Nuclear Information System (INIS)

Gross-Isseroff, R.; Dillon, K.A.; Fieldust, S.J.; Biegon, A.

1990-01-01

In vitro quantitative autoradiography of alpha 1-noradrenergic receptors, using tritiated prazosin as a ligand, was performed on 24 human brains postmortem. Twelve brains were obtained from suicide victims and 12 from matched controls. We found significant lower binding to alpha 1 receptors in several brain regions of the suicide group as compared with matched controls. This decrease in receptor density was evident in portions of the prefrontal cortex, as well as the temporal cortex and in the caudate nucleus. Age, sex, presence of alcohol, and time of death to autopsy did not affect prazosin binding, in our sample, as measured by autoradiography

Freezing of Gait in Parkinson’s Disease Is Associated with Reduced 6-[18F]Fluoro-L-m-tyrosine Uptake in the Locus Coeruleus

Directory of Open Access Journals (Sweden)

Sayaka Asari Ono

2016-01-01

Full Text Available Freezing of gait (FOG is a common disorder in Parkinson’s disease (PD and could be attributed to a reduction in brain noradrenaline. The aim of this study was to determine the relationship between aromatic L-amino acid decarboxylase (AADC activity in the locus coeruleus (LC and FOG in PD using high-resolution positron emission tomography with an AADC tracer, 6-[18F]fluoro-L-m-tyrosine (FMT. We assessed 40 patients with PD and 11 age-matched healthy individuals. PD was diagnosed based on the UK Brain Bank criteria by two movement disorder experts. FOG was directly observed by the clinician and assessed using a patient questionnaire. FMT uptake in the LC, caudate, and putamen was analyzed using PMOD software on coregistered magnetic resonance images. FOG was present in 30 patients. The severity of FOG correlated with the decrease of FMT uptake in the LC regardless of disease duration and the severity of other motor impairments, indicating dysfunction of the noradrenergic network in FOG.

Thyroid Scan and Uptake

Medline Plus

Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake ...

Disinhibition by propranolol and chlordiazepoxide of nonrewarded lever-pressing in the rat is unaffected by dorsal noradrenergic bundle lesion.

Science.gov (United States)

Salmon, P; Tsaltas, E; Gray, J A

1989-03-01

Ten male Sprague-Dawley rats received 6-hydroxydopamine-induced lesions of the dorsal noradrenergic bundle and 10 others underwent control operations. The lesion depleted levels of noradrenaline in the hippocampus to 2% of those in the controls. All rats were then trained for 16 sessions to lever-press in a Skinner box on a variable interval 18 sec schedule of food-reinforcement, then for 42 days on a successive discrimination between periods of variable interval (VI 18 sec) food-reinforcement and periods of extinction. This report describes the effects of chlordiazepoxide (CDP; 5 mg/kg) and propranolol (5 and 10 mg/kg) injected intraperitoneally in both groups on modified ABBA designs after this training. Both drugs increased the response rates in extinction periods. The effect of propranolol was similar at each dose and smaller than that of CDP. Although CDP and propranolol (5 mg/kg) increased variable interval response rates also, this could not account for the effect on extinction response rates. Responding did not differ between the lesioned and control animals and the effects of drugs were similar in each group. It is unlikely that CDP or propranolol release nonrewarded responding by disrupting transmission in the dorsal noradrenergic bundle.

The uptake and overflow of radiolabelled β-adrenoceptor blocking agents by the isolated vas deferens of the rat

International Nuclear Information System (INIS)

Lewis, M.J.

1977-01-01

A comparison of uptake into and overflow from the isolated vas deferens of the rat has been made between [ 3 H]-noradrenaline ([ 3 H]-NA), [ 14 C]-D-sorbitol and three radio-labelled β-adrenoceptor blocking agents, [ 14 C]-practolol, [ 14 C]-(+-)-propranolol and [ 3 H]-penbutolol. The accumulation of [ 3 H]-NA after 30 min incubation was reduced by desmethylimipramine (DMI) 1 x 10 -8 M and was also reduced in vasa from rats pretreated with 6-hydroxydopamine (6-OHDA). This was not so with [ 14 C]-D-sorbitol. 6-OHDA pretreatment of the rats reduced the uptake of [ 3 H]-penbutolol after 30 min incubation but not that of [ 14 C]-propranolol or [ 14 C]-practolol. DMI 1 x 10 -8 M did not alter the tissue uptake of [ 14 C]-propanolol, [ 14 C]-practolol or [ 3 H]-penbutolol. Electrical stimulation of vasa preloaded with [ 3 H]-NA caused a significantly greater increase in [ 3 H]-NA overflow than during the resting, unstimulated periods. No such increase in overflow was observed with [ 14 C]-sorbitol or any of the three β-adrenoceptor blocking agents used. The β-adrenoceptor blocking agent penbutolol was shown to possess adrenergic neurone blocking activity in the isolated vas deferens of the rat. It is concluded that any effect that practolol or (+-)-propranolol have on noradrenergic neurones is brought about without the need for these drugs to gain access to the interior of the neurone. (author)

Locus coeruleus to basolateral amygdala noradrenergic projections promote anxiety-like behavior.

Science.gov (United States)

McCall, Jordan G; Siuda, Edward R; Bhatti, Dionnet L; Lawson, Lamley A; McElligott, Zoe A; Stuber, Garret D; Bruchas, Michael R

2017-07-14

Increased tonic activity of locus coeruleus noradrenergic (LC-NE) neurons induces anxiety-like and aversive behavior. While some information is known about the afferent circuitry that endogenously drives this neural activity and behavior, the downstream receptors and anatomical projections that mediate these acute risk aversive behavioral states via the LC-NE system remain unresolved. Here we use a combination of retrograde tracing, fast-scan cyclic voltammetry, electrophysiology, and in vivo optogenetics with localized pharmacology to identify neural substrates downstream of increased tonic LC-NE activity in mice. We demonstrate that photostimulation of LC-NE fibers in the BLA evokes norepinephrine release in the basolateral amygdala (BLA), alters BLA neuronal activity, conditions aversion, and increases anxiety-like behavior. Additionally, we report that β-adrenergic receptors mediate the anxiety-like phenotype of increased NE release in the BLA. These studies begin to illustrate how the complex efferent system of the LC-NE system selectively mediates behavior through distinct receptor and projection-selective mechanisms.

Both a Nicotinic Single Nucleotide Polymorphism (SNP) and a Noradrenergic SNP Modulate Working Memory Performance when Attention is Manipulated

OpenAIRE

Greenwood, Pamela M.; Sundararajan, Ramya; Lin, Ming-Kuan; Kumar, Reshma; Fryxell, Karl J.; Parasuraman, Raja

2009-01-01

We investigated the relation between the two systems of visuospatial attention and working memory by examining the effect of normal variation in cholinergic and noradrenergic genes on working memory performance under attentional manipulation. We previously reported that working memory for location was impaired following large location precues, indicating the scale of visuospatial attention has a role in forming the mental representation of the target. In one of the first studies to compare ef...

ESR analyses for teeth from the open-air site at Attirampakkam, India: Clues to complex U uptake and paleoenvironmental change

International Nuclear Information System (INIS)

Blackwell, Bonnie A.B.; Montoya, Andres; Blickstein, Joel I.B.; Skinner, Anne R.; Pappu, Shanti; Gunnell, Yanni; Taieb, Maurice; Kumar, Akhilesh; Lundberg, Joyce A.

2007-01-01

In open-air sites, diagenetic alteration makes teeth difficult to analyze with electron spin resonance (ESR). Despite strong diagenetic alteration, three ungulate teeth from Pleistocene fluvial sediment in the open-air Paleolithic site at Attirampakkam, Tamil Nadu, India, were analyzed using standard and isochron ESR. Diagenetic alteration features in two teeth indicated rapid submergence in quiet saline to hypersaline water, following a short subaerial exposure, while the third remained constantly buried under reducing conditions. Geochemical signatures and ESR data all indicate that the teeth experienced at least three independent U uptake events during diagenesis, including two that occurred long after burial

Cold-induced vasoconstriction at forearm and hand skin sites: the effect of age

OpenAIRE

Kingma, B.R.M.; Frijns, A.J.H.; Saris, W.H.M.; Steenhoven, van, A.A.; Marken Lichtenbelt, van, W.D.

2010-01-01

During mild cold exposure, elderly are at risk of hypothermia. In humans, glabrous skin at the hands is well adapted as a heat exchanger. Evidence exists that elderly show equal vasoconstriction due to local cooling at the ventral forearm, yet no age effects on vasoconstriction at hand skin have been studied. Here, we tested the hypotheses that at hand sites (a) elderly show equal vasoconstriction due to local cooling and (b) elderly show reduced response to noradrenergic stimuli. Skin perfus...

Knowledge, attitude, and uptake related to human papillomavirus vaccination among young women in Germany recruited via a social media site.

Science.gov (United States)

Remschmidt, Cornelius; Walter, Dietmar; Schmich, Patrick; Wetzstein, Matthias; Deleré, Yvonne; Wichmann, Ole

2014-01-01

Many industrialized countries have introduced human papillomavirus (HPV) vaccination of young women, but vaccine uptake often remains suboptimal. This study aimed to investigate whether a social media site like Facebook is an appropriate tool to assess knowledge, attitude and uptake related to HPV vaccination in young women in Germany. Between December 2012 and January 2013 two different targeting strategies were implemented on Facebook, providing a link to an online questionnaire. Advertisements were displayed to female Facebook users aged 18-25 years living in Germany. During the simple targeting strategy, advertisements comprised health-related images along with various short titles and text messages. During the focused strategy, advertisements were targeted to users who in addition had certain fashion brands or pop stars listed on their profiles. The targeting strategies were compared with respect to participant characteristics. Univariate and multivariate analyses were used to identify factors associated with HPV vaccine uptake. A total of 1161 women participated. The two targeting strategies resulted in significant differences regarding educational status and migrant background. Overall, awareness of HPV was high, but only 53% received at least one vaccine dose. In multivariate analysis, HPV vaccine uptake was independently associated with a physician's recommendation and trust in vaccine effectiveness. Concerns of adverse effects were negatively associated with vaccine uptake. Social network recruitment permits fast and convenient access to young people. Sample characteristics can be manipulated by adjusting targeting strategies. There is further need for promoting knowledge of HPV vaccination among young women. Physicians have a major role in the vaccination decision-making process of young women.

Effect of amine uptake inhibitors on the uptake of 14C-bretylium in intact and degenerating sympathetic nerves of the rat

International Nuclear Information System (INIS)

Almgren, O.

1981-01-01

The effect of different amine uptake inhibitors on the accumulation of 14 C-bretylium in sympathetically denervated or decentralized salivary glands were studied in vivo in rats 11-14 hours after the surgical intervention. The time period chosen is known to be critical for the delaying effect of bretylium on the degeneration transmitter release in sympathetically innervated organs. Cocaine, desmethylimipramine (DMI), protriptyline or reserpine all depressed the uptake of 14 C-bretylium in both denervated and decentralized salivary glands, cocaine being the most efficient one. DMI and protriptyline, but not cocaine inhibit the degeneration delaying effect of bretylium, while all three agents inhibit amine uptake at level of the nerve cell membrane. Apparently, bretylium reaches the critical sites of its degeneration delaying action by the axonal amine pump but only a small fraction of the drug entering the degenerating adrenergic nerve terminal is needed at the critical sites to interact with the degeneration processes. The difference between the tricyclic antidepressants on one hand and cocaine on the other with respect to the effect on the degeneration delaying action of bretylium, must depend on some action different from the axonal membrane uptake inhibition. Reserpine which is known not to interfere with the delaying effect of bretylium on the denervation degeneration did reduce the uptake of 14 C-bretylium. This fact seems to indicate that the site of action of bretylium is located outside the adrenergic nerve granules. (author)

Sphagnum mosses--masters of efficient N-uptake while avoiding intoxication.

Science.gov (United States)

Fritz, Christian; Lamers, Leon P M; Riaz, Muhammad; van den Berg, Leon J L; Elzenga, Theo J T M

2014-01-01

Peat forming Sphagnum mosses are able to prevent the dominance of vascular plants under ombrotrophic conditions by efficiently scavenging atmospherically deposited nitrogen (N). N-uptake kinetics of these mosses are therefore expected to play a key role in differential N availability, plant competition, and carbon sequestration in Sphagnum peatlands. The interacting effects of rain N concentration and exposure time on moss N-uptake rates are, however, poorly understood. We investigated the effects of N-concentration (1, 5, 10, 50, 100, 500 µM), N-form ((15)N-ammonium or nitrate) and exposure time (0.5, 2, 72 h) on uptake kinetics for Sphagnum magellanicum from a pristine bog in Patagonia (Argentina) and from a Dutch bog exposed to decades of N-pollution. Uptake rates for ammonium were higher than for nitrate, and N-binding at adsorption sites was negligible. During the first 0.5 h, N-uptake followed saturation kinetics revealing a high affinity (Km 3.5-6.5 µM). Ammonium was taken up 8 times faster than nitrate, whereas over 72 hours this was only 2 times. Uptake rates decreased drastically with increasing exposure times, which implies that many short-term N-uptake experiments in literature may well have overestimated long-term uptake rates and ecosystem retention. Sphagnum from the polluted site (i.e. long-term N exposure) showed lower uptake rates than mosses from the pristine site, indicating an adaptive response. Sphagnum therefore appears to be highly efficient in using short N pulses (e.g. rainfall in pristine areas). This strategy has important ecological and evolutionary implications: at high N input rates, the risk of N-toxicity seems to be reduced by lower uptake rates of Sphagnum, at the expense of its long-term filter capacity and related competitive advantage over vascular plants. As shown by our conceptual model, interacting effects of N-deposition and climate change (changes in rainfall) will seriously alter the functioning of Sphagnum peatlands.

Sphagnum Mosses - Masters of Efficient N-Uptake while Avoiding Intoxication

Science.gov (United States)

Fritz, Christian; Lamers, Leon P. M.; Riaz, Muhammad; van den Berg, Leon J. L.; Elzenga, Theo J. T. M.

2014-01-01

Peat forming Sphagnum mosses are able to prevent the dominance of vascular plants under ombrotrophic conditions by efficiently scavenging atmospherically deposited nitrogen (N). N-uptake kinetics of these mosses are therefore expected to play a key role in differential N availability, plant competition, and carbon sequestration in Sphagnum peatlands. The interacting effects of rain N concentration and exposure time on moss N-uptake rates are, however, poorly understood. We investigated the effects of N-concentration (1, 5, 10, 50, 100, 500 µM), N-form (15N - ammonium or nitrate) and exposure time (0.5, 2, 72 h) on uptake kinetics for Sphagnum magellanicum from a pristine bog in Patagonia (Argentina) and from a Dutch bog exposed to decades of N-pollution. Uptake rates for ammonium were higher than for nitrate, and N-binding at adsorption sites was negligible. During the first 0.5 h, N-uptake followed saturation kinetics revealing a high affinity (Km 3.5–6.5 µM). Ammonium was taken up 8 times faster than nitrate, whereas over 72 hours this was only 2 times. Uptake rates decreased drastically with increasing exposure times, which implies that many short-term N-uptake experiments in literature may well have overestimated long-term uptake rates and ecosystem retention. Sphagnum from the polluted site (i.e. long-term N exposure) showed lower uptake rates than mosses from the pristine site, indicating an adaptive response. Sphagnum therefore appears to be highly efficient in using short N pulses (e.g. rainfall in pristine areas). This strategy has important ecological and evolutionary implications: at high N input rates, the risk of N-toxicity seems to be reduced by lower uptake rates of Sphagnum, at the expense of its long-term filter capacity and related competitive advantage over vascular plants. As shown by our conceptual model, interacting effects of N-deposition and climate change (changes in rainfall) will seriously alter the functioning of Sphagnum peatlands

Radioiodine uptake in inactive pulmonary tuberculosis

International Nuclear Information System (INIS)

Bakheet, S.M.; Powe, J.; Al Suhaibani, H.; Hammami, M.M.; Bazarbashi, M.

1999-01-01

Radioiodine may accumulate at sites of inflammation or infection. We have seen such accumulation in six thyroid cancer patients with a history of previously treated pulmonary tuberculosis. We also review the causes of false-positive radioiodine uptake in lung infection/inflammation. Eight foci of radioiodine uptake were seen on six iodine-123 diagnostic scans. In three foci, the uptake was focal and indistinguishable from thyroid cancer pulmonary metastases from thyroid cancer. In the remaining foci, the uptake appeared nonsegmental, linear or lobar, suggesting a false-positive finding. The uptake was unchanged, variable in appearance or non-persistent on follow-up scans and less extensive than the fibrocystic changes seen on chest radiographs. In the two patients studied, thyroid hormone level did not affect the radioiodine lung uptake and there was congruent gallium-67 uptake. None of the patients had any evidence of thyroid cancer recurrence or of reactivation of tuberculosis and only two patients had chronic intermittent chest symptoms. Severe bronchiectasis, active tuberculosis, acute bronchitis, respiratory bronchiolitis, rheumatoid arthritis-associated lung disease and fungal infection such as Allescheria boydii and aspergillosis can lead to different patterns of radioiodine chest uptake mimicking pulmonary metastases. Pulmonary scarring secondary to tuberculosis may predispose to localized radioiodine accumulation even in the absence of clinically evident active infection. False-positive radioiodine uptake due to pulmonary infection/inflammation should be considered in thyroid cancer patients prior to the diagnosis of pulmonary metastases. (orig.)

Individually reared rats

International Nuclear Information System (INIS)

Kraeuchi, K.; Gentsch, C.; Feer, H.

1981-01-01

The influence of social isolation in rats on postsynaptic alpha 1 - and beta-adrenergic receptors, on the cAMP generating system and on the presynaptic uptake mechanism in the central noradrenergic system was examined in different brain regions. Rearing rats in isolation from the 19th day of life for 12 weeks leads in all regions to a general tendency for a reduction in 3 H-DHA binding, to an enhanced 3 H-WB4101 binding and to a decreased responsiveness of the noradrenaline sensitive cAMP generating system. These changes reach significance only in the pons-medulla-thallamusregion. Isolated rats showed an increased synaptosomal uptake of noradrenaline, most pronounced and significant in the hypothalamus. Our data provide further support for a disturbance in central noradrenergic function in isolated rats. (author)

Selective Serotonergic (SSRI) Versus Noradrenergic (SNRI) Reuptake Inhibitors with and without Acetylsalicylic Acid in Major Depressive Disorder.

Science.gov (United States)

Zdanowicz, Nicolas; Reynaert, Christine; Jacques, Denis; Lepiece, Brice; Dubois, Thomas

2017-09-01

Antidepressant medication efficacy remains a major research challenge. Here, we explored four questions: whether noradrenergic antidepressants are more effective than serotonergic antidepressants; whether the addition of 100 mg acetylsalicylic acid (ASA) changes antidepressant efficacy; whether the long-term efficacy differs depending on the antidepressant and the addition of ASA; and whether serum levels of brain-derived neurotrophic factor (BDNF) are clinically informative. In a two-year study, forty people with major depressive disorder were randomly assigned to groups that received an SSRI (escitalopram) or an SNRI (duloxetine), each group received concomitant ASA (100 mg) or a placebo. Sociodemographic data were recorded and patients under went regular assessments with the Hamilton depression scale (HDS) and clinical global impression (CGI) scale. Serum levels of BDNF were measured four times per year. There was no significant difference in efficacy between the two antidepressants or between antidepressant treatment with and without ASA. However, subgroup comparisons revealed that the duloxetine + ASA (DASA) subgroup showed a more rapid improvement in HDS score as early as 2 months (t=-3.114, p=0.01), in CGI score at 5 months (t=-2.119, p=0.05), and a better remission rate (χ 2 =6.296, p 0.012) than the escitalopram + placebo (EP) subgroup. Serum BDNF before treatment was also higher in the DASA subgroup than in the EP subgroup (t=3.713; p=0.002). This suggest two hypotheses: either a noradrenergic agent combined with ASA is more effective in treating depression than a serotonergic agent alone, or the level of serum BDNF before treatment is a precursor marker of the response to antidepressants. Further research is needed to test these hypotheses.

Factors influencing physiological FDG uptake in the intestine

International Nuclear Information System (INIS)

Yasuda, Seiei; Takahashi, Wakoh; Takagi, Shigeharu; Fujii, Hirofumi; Ide, Michiru; Shohtsu, Akira

1998-01-01

The intestine is a well-known site of physiological 18 F-fluorodeoxyglucose (FDG) accumulation in positron emission tomography (PET). To identify factors influencing physiological FDG uptake in the intestine, the intensity of FDG uptake was evaluated in a total of 1,068 healthy adults. Non-attenuation-corrected whole-body PET images were obtained for all subjects and visually evaluated. Subjects were then classified into two groups according to the intensity of intestinal FDG uptake. Sex, age, presence or absence of constipation, and serum glucose, hemoglobin A 1 c, and free fatty acid levels were compared between the two groups. High intestinal FDG uptake was observed at an overall rate of 11.0%. Sex (female), age, and bowel condition (constipation) were found to affect intestinal FDG uptake. The factors we identified lead to further questions the relationship between intestinal motility and glucose uptake that warrant further study. (author)

Usefulness and pitfalls of MAA SPECT/CT in identifying digestive extrahepatic uptake when planning liver radioembolization

International Nuclear Information System (INIS)

Lenoir, Laurence; Garin, Etienne; Edeline, Julien; Rolland, Yann; Pracht, Marc; Raoul, Jean-Luc; Ardisson, Valerie; Bourguet, Patrick; Clement, Bruno; Boucher, Eveline

2012-01-01

Identifying gastroduodenal uptake of 99m Tc-macroaggregated albumin (MAA), which is associated with an increased risk of ulcer disease, is a crucial part of the therapeutic management of patients undergoing radioembolization for liver tumours. Given this context, the use of MAA single photon emission computed tomography (SPECT)/CT may be essential, but the procedure has still not been thoroughly evaluated. The aim of this retrospective study was to determine the effectiveness of MAA SPECT/CT in identifying digestive extrahepatic uptake, while determining potential diagnostic pitfalls. Overall, 139 MAA SPECT/CT scans were performed on 103 patients with different hepatic tumour types. Patients were followed up for at least 6 months according to standard requirements. Digestive, or digestive-like, uptake other than free pertechnetate was identified in 5.7% of cases using planar imaging and in 36.6% of cases using SPECT/CT. Uptake sites identified by SPECT/CT included the gastroduodenal region (3.6%), gall bladder (12.2%), portal vein thrombosis (6.5%), hepatic artery (6.5%), coil embolization site (2.1%) as well as falciform artery (5.0%). For 2.1% of explorations, a coregistration error between SPECT and CT imaging could have led to a false diagnosis by erroneously attributing an uptake site to the stomach or gall bladder, when the uptake actually occurred in the liver. SPECT/CT is more efficacious than planar imaging in identifying digestive extrahepatic uptake sites, with extrahepatic uptake observed in one third of scans using the former procedure. However, more than half of the uptake sites in our study were vascular in nature, without therapeutic implications. The risk of coregistration errors must also be kept in mind. (orig.)

Usefulness and pitfalls of MAA SPECT/CT in identifying digestive extrahepatic uptake when planning liver radioembolization

Energy Technology Data Exchange (ETDEWEB)

Lenoir, Laurence; Garin, Etienne [Comprehensive Cancer Institute Eugene Marquis, Department of Nuclear Medicine, CS 44229, Rennes (France); University of Rennes 1, Rennes (France); Liver Metabolisms and Cancer, INSERM, U-991, Rennes (France); Edeline, Julien [University of Rennes 1, Rennes (France); Comprehensive Cancer Institute Eugene Marquis, Department of Medical Oncology, CS 44229, Rennes (France); Rolland, Yann [Comprehensive Cancer Institute Eugene Marquis, Department of Medical Imaging, CS 44229, Rennes (France); Pracht, Marc [Comprehensive Cancer Institute Eugene Marquis, Department of Medical Oncology, CS 44229, Rennes (France); Raoul, Jean-Luc [Comprehensive Cancer Institute Paoli Calmette, Department of Medical Oncology, Marseille (France); Ardisson, Valerie [Comprehensive Cancer Institute Eugene Marquis, Department of Nuclear Medicine, CS 44229, Rennes (France); Bourguet, Patrick [Comprehensive Cancer Institute Eugene Marquis, Department of Nuclear Medicine, CS 44229, Rennes (France); University of Rennes 1, Rennes (France); Clement, Bruno [Liver Metabolisms and Cancer, INSERM, U-991, Rennes (France); Boucher, Eveline [Liver Metabolisms and Cancer, INSERM, U-991, Rennes (France); Comprehensive Cancer Institute Eugene Marquis, Department of Medical Oncology, CS 44229, Rennes (France)

2012-05-15

Identifying gastroduodenal uptake of {sup 99m}Tc-macroaggregated albumin (MAA), which is associated with an increased risk of ulcer disease, is a crucial part of the therapeutic management of patients undergoing radioembolization for liver tumours. Given this context, the use of MAA single photon emission computed tomography (SPECT)/CT may be essential, but the procedure has still not been thoroughly evaluated. The aim of this retrospective study was to determine the effectiveness of MAA SPECT/CT in identifying digestive extrahepatic uptake, while determining potential diagnostic pitfalls. Overall, 139 MAA SPECT/CT scans were performed on 103 patients with different hepatic tumour types. Patients were followed up for at least 6 months according to standard requirements. Digestive, or digestive-like, uptake other than free pertechnetate was identified in 5.7% of cases using planar imaging and in 36.6% of cases using SPECT/CT. Uptake sites identified by SPECT/CT included the gastroduodenal region (3.6%), gall bladder (12.2%), portal vein thrombosis (6.5%), hepatic artery (6.5%), coil embolization site (2.1%) as well as falciform artery (5.0%). For 2.1% of explorations, a coregistration error between SPECT and CT imaging could have led to a false diagnosis by erroneously attributing an uptake site to the stomach or gall bladder, when the uptake actually occurred in the liver. SPECT/CT is more efficacious than planar imaging in identifying digestive extrahepatic uptake sites, with extrahepatic uptake observed in one third of scans using the former procedure. However, more than half of the uptake sites in our study were vascular in nature, without therapeutic implications. The risk of coregistration errors must also be kept in mind. (orig.)

Effects of catecholamine agonists and antagonists on alcohol uptake in rats with different stages of experimental alcoholism

Energy Technology Data Exchange (ETDEWEB)

Burov, Yu V; Varov, A I

1985-02-01

The effects of various catecholamine agonists and antagonists on 15% ethanol ingestion by outbred albino rats were studied in relation to the stage of experimental alcoholism. In animals with stage I and II alcoholism, alcohol intake was most profoundly inhibited by administration of alpha-adrenoblockers (AA), klofelin, and alpha-methyl-DOPA (AMD), while L-DOPA and cocaine stimulated a significant increase in ethanol ingestion. In stage III alcoholism, both AA and L-DOPA depressed alcohol intake, while AMD and haloperidol had a stimulatory effect. It appears, therefore, that different neurochemical mechanisms are involved in alcohol dependence in different stages of experimental alcoholism in the rat. Furthermore, it seems evident that alpha-adrenergic receptors have a key function in maintaining alcohol dependence. In well-established physical dependence, the importance of the noradrenergic system seems to diminish and dopaminergic mechanisms appear to become predominant. Consequently, in the initial stages of alcoholism, agents which depress the noradrenergic system seem indicated, while at the stage of physical dependence agents which normalize noradrenergic mechanisms and depress dopaminergic mechanisms should be considered. 13 references.

Noradrenergic System in Down Syndrome and Alzheimer's Disease A Target for Therapy.

Science.gov (United States)

Phillips, Cristy; Fahimi, Atoossa; Das, Devsmita; Mojabi, Fatemeh S; Ponnusamy, Ravikumar; Salehi, Ahmad

2016-01-01

Locus coeruleus (LC) neurons in the brainstem send extensive noradrenergic (NE)-ergic terminals to the majority of brain regions, particularly those involved in cognitive function. Both Alzheimer's disease (AD) and Down syndrome (DS) are characterized by similar pathology including significant LC degeneration and dysfunction of the NE-ergic system. Extensive loss of NE-ergic terminals has been linked to alterations in brain regions vital for cognition, mood, and executive function. While the mechanisms by which NE-ergic abnormalities contribute to cognitive dysfunction are not fully understood, emergent evidence suggests that rescue of NE-ergic system can attenuate neuropathology and cognitive decline in both AD and DS. Therapeutic strategies to enhance NE neurotransmission have undergone limited testing. Among those deployed to date are NE reuptake inhibitors, presynaptic α-adrenergic receptor antagonists, NE prodrugs, and β-adrenergic agonists. Here we examine alterations in the NE-ergic system in AD and DS and suggest that NE-ergic system rescue is a plausible treatment strategy for targeting cognitive decline in both disorders.

A1 noradrenergic neurons lesions reduce natriuresis and hypertensive responses to hypernatremia in rats.

Directory of Open Access Journals (Sweden)

Elaine Fernanda da Silva

Full Text Available Noradrenergic neurons in the caudal ventrolateral medulla (CVLM; A1 group contribute to cardiovascular regulation. The present study assessed whether specific lesions in the A1 group altered the cardiovascular responses that were evoked by hypertonic saline (HS infusion in non-anesthetized rats. Male Wistar rats (280-340 g received nanoinjections of antidopamine-β-hydroxylase-saporin (A1 lesion, 0.105 ng.nL(-1 or free saporin (sham, 0.021 ng.nL(-1 into their CVLMs. Two weeks later, the rats were anesthetized (2% halothane in O2 and their femoral artery and vein were catheterized and led to exit subcutaneously between the scapulae. On the following day, the animals were submitted to HS infusion (3 M NaCl, 1.8 ml • kg(-1, b.wt., for longer than 1 min. In the sham-group (n = 8, HS induced a sustained pressor response (ΔMAP: 35±3.6 and 11±1.8 mmHg, for 10 and 90 min after HS infusion, respectively; P<0.05 vs. baseline. Ten min after HS infusion, the pressor responses of the anti-DβH-saporin-treated rats (n = 11were significantly smaller(ΔMAP: 18±1.4 mmHg; P<0.05 vs. baseline and vs. sham group, and at 90 min, their blood pressures reached baseline values (2±1.6 mmHg. Compared to the sham group, the natriuresis that was induced by HS was reduced in the lesioned group 60 min after the challenge (196±5.5 mM vs. 262±7.6 mM, respectively; P<0.05. In addition, A1-lesioned rats excreted only 47% of their sodium 90 min after HS infusion, while sham animals excreted 80% of their sodium. Immunohistochemical analysis confirmed a substantial destruction of the A1 cell group in the CVLM of rats that had been nanoinjected withanti-DβH-saporin. These results suggest that medullary noradrenergic A1 neurons are involved in the excitatory neural pathway that regulates hypertensive and natriuretic responses to acute changes in the composition of body fluid.

Uptake of gallium-67 citrate in clean surgical incisions after colorectal surgery

International Nuclear Information System (INIS)

Lin Wanyu; Wang Shyhjen; Tsai Shihchuan; Chao Tehsin

2001-01-01

Non-specific accumulation of gallium-67 citrate (gallium) in uncomplicated surgical incisions is not uncommon. It is important to know the normal pattern of gallium uptake at surgical incision sites in order to properly interpret the gallium scan when investigating possible wound infection in patients who have undergone abdominal surgery. We studied 42 patients without wound infection after colorectal surgery and performed gallium scans within 40 days after surgery. Patients were divided into three groups according to the interval between the operation and the scan. In group A (26 patients) gallium scan was performed within 7 days after surgery, in group B (8 patients) between 8 and 14 days after surgery, and in group C (8 patients) between 15 and 40 days after surgery. Our data showed that in group A, 61.5% had gallium accumulation at the surgical incision site. In group B, 50% had accumulation of gallium at the surgical incision site, while in group C only one patient (12.5%) showed gallium uptake. It is concluded that the incidence of increased gallium uptake at clean surgical incision sites is high after colorectal surgery. Nuclear medicine physicians should bear in mind the high incidence of non-specific gallium uptake at such sites during the interpretation of possible wound infection in patients after colorectal surgery. (orig.)

Mechanism of Uptake of Trace Elements by Plants

International Nuclear Information System (INIS)

Broda, E.

1965-01-01

MECHANISM OF UPTAKE OF TRACE ELEMENTS BY PLANTS (EXPERIMENTS WlTH RADIOZINC). Some authors have assumed that the uptake of (essential or non-essential) trace elements by plants is due to active transport, and therefore needs metabolic energy. In our laboratory it has been found that the uptake of zinc (“6”5Zn) by chlorella and barley roots is, in the main, a passive process, and is based largely on ion exchange. In these experiments the Zn system contrasted sharply with actively transporting systems, e. g. the K system, although the extent of accumulation may be similar: (1) decouplers (DNP, azide) or anaerobiosis do not depress the uptake of Zn: (2) plants killed by grinding, freezing or alcohol treatment take up more Zn than living plants: (3) the temperature coefficient of the Zn uptake is small: (4) many ions compete with Zn, i.e. the uptake is unspecific. We have measured - primarily with dead cells, where equilibria are reached easily - the competition of several foreign ions with radiozinc at fixed pH (usually 6). These values have been compared with analogous values obtained with radiozinc (and verified with radiocopper) in respect to cation exchange resins. It is concluded from the sequence of the different ions that the active sites in the cells are mainly carboxyl groups. Probably most of the ‘exchanger’ consists of carbohydrate derivatives in the cell wall, i.e. in the ‘free space’, However, both by Langmuir analysis of the observed ‘uptake isotherm’ and by radiochemical work with partly blocked material, sites with anomalous affinity to Zn have been demonstrated. These may be imidazol groups in the proteins known to bind zinc strongly by complexation. (author)

Noradrenergic facilitation of shock-probe defensive burying in lateral septum of rats, and modulation by chronic treatment with desipramine.

Science.gov (United States)

Bondi, Corina O; Barrera, Gabriel; Lapiz, M Danet S; Bedard, Tania; Mahan, Amy; Morilak, David A

2007-03-30

We have previously shown that acute stress-induced release of norepinephrine (NE) facilitates anxiety-like behavioral responses to stress, such as reduction in open-arm exploration on the elevated-plus maze and in social behavior on the social interaction test. Since these responses represent inhibition of ongoing behavior, it is important to also address whether NE facilitates a response that represents an activation of behavior. Correspondingly, it is unknown how a chronic elevation in tonic steady-state noradrenergic (NA) neurotransmission induced by NE reuptake blockade might alter this acute modulatory function, a regulatory process that may be pertinent to the anxiolytic effects of NE reuptake blockers such as desipramine (DMI). Therefore, in this study, we investigated noradrenergic modulation of the shock-probe defensive burying response in the lateral septum (LS). In experiment 1, shock-probe exposure induced an acute 3-fold increase in NE levels measured in LS of male Sprague-Dawley rats by microdialysis. Shock-probe exposure also induced a modest rise in plasma ACTH, taken as an indicator of perceived stress, that returned to baseline more rapidly in rats that were allowed to bury the probe compared to rats prevented from burying by providing them with minimal bedding, indicating that the active defensive burying behavior is an effective coping strategy that reduces the impact of acute shock probe-induced stress. In experiment 2, blockade of either alpha(1)- or beta-adrenergic receptors in LS by local antagonist microinjection immediately before testing reduced defensive burying and increased immobility. In the next experiment, chronic DMI treatment increased basal extracellular NE levels in LS, and attenuated the acute shock probe-induced increase in NE release in LS relative to baseline. Chronic DMI treatment decreased shock-probe defensive burying behavior in a time-dependent manner, apparent only after 2 weeks or more of drug treatment. Moreover

Quantification of radionuclide uptake levels for primary bone tumors

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Hasford Francis

2015-04-01

Full Text Available The purpose of the study is to quantify the level of uptake of administered radionuclide in primary bone tumors for patients undergoing bone scintigraphy. Retrospective study on 48 patient's scintigrams to quantify the uptake levels of administered radiopharmaceuticals was performed in a nuclear medicine unit in Ghana. Patients were administered with activity ranging between 0.555 and 1.110 MBq (15–30 mCi, and scanned on Siemens e.cam SPECT system. Analyses on scintigrams were performed with Image J software by drawing regions of interest (ROIs over identified hot spots (pathologic sites. Nine skeletal parts namely cranium, neck, shoulder, sacrum, sternum, vertebra, femur, ribcage, and knee were considered in the study, which involved 96 identified primary tumors. Radionuclide uptakes were quantified in terms of the estimated counts of activity per patient for identified tumor sites. Average normalized counts of activity (nGMC per patient ranged from 5.2759 ± 0.6590 cts/mm2/MBq in the case of cranium tumors to 72.7569 ± 17.8786 cts/mm2/MBq in the case of ribcage tumors. The differences in uptake levels could be attributed to different mechanisms of Tc-99m MDP uptake in different types of bones, which is directly related to blood flow and degree of osteoblastic activity. The overall normalized count of activity for the 96 identified tumors was estimated to be 23.0350 ± 19.5424 cts/mm2/MBq. The study revealed highest uptake of activity in ribcage and least uptake in cranium. Quantification of radionuclide uptakes in tumors is important and recommended in assessing patient's response to therapy, doses to critical organs and in diagnosing tumors.

Tianeptine: 5-HT uptake sites and 5-HT(1-7) receptors modulate memory formation in an autoshaping Pavlovian/instrumental task.

Science.gov (United States)

Meneses, Alfredo

2002-05-01

Recent studies using invertebrate and mammal species have revealed that, endogenous serotonin (5-hydroxytryptamine, 5-HT) modulates cognitive processes, particularly learning and memory, though, at present, it is unclear the manner, where, and how long 5-HT systems are involved. Hence in this work, an attempt was made to study the effects of 5-HT endogenous on memory formation, using a 5-HT uptake facilitator (tianeptine) and, selective 5-HT(1-7) receptor antagonists to determine whether 5-HT uptake sites and which 5-HT receptors are involved, respectively. Results showed that post-training tianeptine injection enhanced memory consolidation in an autoshaping Pavlovian/instrumental learning task, which has been useful to detect changes on memory formation elicited by drugs or aging. On interaction experiments, ketanserin (5-HT(1D/2A/2C) antagonist) slightly enhanced tianeptine effects, while WAY 100635 (5-HT(1A) antagonist), SB-224289 (5-HT(1B) inverse agonist), SB-200646 (5-HT(2B/2C) antagonist), ondansetron (5-HT(3) antagonist), GR 127487 (5-HT(4) antagonist), Ro 04-6790 (5-HT(6) antagonist), DR 4004 (5-HT(7) antagonist), or fluoxetine (an inhibitor of 5-HT reuptake) blocked the facilitatory tianeptine effect. Notably, together tianeptine and Ro 04-6790 impaired learning consolidation. Moreover, 5-HT depletion completely reversed the tianeptine effect. Tianeptine also normalized an impaired memory elicited by scopolamine (an antimuscarinic) or dizocilpine (non-competitive glutamatergic antagonist), while partially reversed that induced by TFMPP (5-HT(1B/1D/2A-2C/7) agonist/antagonist). Finally, tianeptine-fluoxetine coadministration had no effect on learning consolidation; nevertheless, administration of an acetylcholinesterase inhibitor, phenserine, potentiated subeffective tianeptine or fluoxetine doses. Collectively, these data confirmed that endogenously 5-HT modulates, via uptake sites and 5-HT(1-7) receptors, memory consolidation, and are consistent with the

Uptake of antibiotics by human polymorphonuclear leukocyte cytoplasts

International Nuclear Information System (INIS)

Hand, W.L.; King-Thompson, N.L.

1990-01-01

Enucleated human polymorphonuclear leukocytes (PMN cytoplasts), which have no nuclei and only a few granules, retain many of the functions of intact neutrophils. To better define the mechanisms and intracellular sites of antimicrobial agent accumulation in human neutrophils, we studied the antibiotic uptake process in PMN cytoplasts. Entry of eight radiolabeled antibiotics into PMN cytoplasts was determined by means of a velocity gradient centrifugation technique. Uptakes of these antibiotics by cytoplasts were compared with our findings in intact PMN. Penicillin entered both intact PMN and cytoplasts poorly. Metronidazole achieved a concentration in cytoplasts (and PMN) equal to or somewhat less than the extracellular concentration. Chloramphenicol, a lipid-soluble drug, and trimethoprim were concentrated three- to fourfold by cytoplasts. An unusual finding was that trimethroprim, unlike other tested antibiotics, was accumulated by cytoplasts more readily at 25 degrees C than at 37 degrees C. After an initial rapid association with cytoplasts, cell-associated imipenem declined progressively with time. Clindamycin and two macrolide antibiotics (roxithromycin, erythromycin) were concentrated 7- to 14-fold by cytoplasts. This indicates that cytoplasmic granules are not essential for accumulation of these drugs. Adenosine inhibited cytoplast uptake of clindamycin, which enters intact phagocytic cells by the membrane nucleoside transport system. Roxithromycin uptake by cytoplasts was inhibited by phagocytosis, which may reduce the number of cell membrane sites available for the transport of macrolides. These studies have added to our understanding of uptake mechanisms for antibiotics which are highly concentrated in phagocytes

Variable effects of plant colonization on black slate uptake into microbial PLFAs

Science.gov (United States)

Seifert, Anne-Gret; Trumbore, Susan; Xu, Xiaomei; Zhang, Dachung; Gleixner, Gerd

2013-04-01

Microbial degradation of carbon derived from black shale and slate has been shown in vitro. However, in natural settings where other labile carbon sources are likely to exist, this has not been previously demonstrated. We investigated the uptake of ancient carbon derived from slate weathering and from recently photosynthesised organic matter by different groups of microorganisms. Therefore we isolated microbial biomarkers (phospholipid fatty acids, PLFAs) from black slates collected at a chronosequence of waste piles which differed in age and vegetation cover. We quantified the amount of PLFAs and performed stable isotope and radiocarbon measurements on individual or grouped PLFAs to quantify the fraction of slate derived carbon. We used black slate from a pile heaped in the 1950s with either uncovered black slate material (bare site) or material slightly colonized by small plants (greened site) and from a forested leaching pile (forested site) used for alum-mining in the 19th century. Colonization by plants influenced the amount and composition of the microbial community. Greater amounts of PLFAs (5410 ng PLFA/g dw) were extracted from slate sampled at the forested site as opposed to the bare site (960 ng PLFAs/g dw) or the greened (annual grasses and mosses) rock waste pile (1050 ng PLFAs/g dw). We found the highest proportion of PLFAs representing Gram-negative bacteria on the forested site and the highest proportion of PLFAs representing Gram-positive bacteria on the bare site. The fungal PLFA was most abundant at the greened site. Sites with less plant colonization (bare and greened site) tended to have more depleted δ13C values compared to the forested site. Radiocarbon measurements on PLFAs indicated that fungi and Gram-positive bacteria were best adapted to black slate carbon uptake. In the fungal PLFA (combined bare and greened waste pile sample) and in PLFAs of Gram-positive bacteria (greened site) we measured 39.7% and 28.9% ancient carbon uptake

Uptake of heavy metals by Typha capensis from wetland sites polluted by effluent from mineral processing plants: implications of metal-metal interactions.

Science.gov (United States)

Zaranyika, M F; Nyati, W

2017-10-01

The aim of the present work was to demonstrate the existence of metal-metal interactions in plants and their implications for the absorption of toxic elements like Cr. Typha capensis , a good accumulator of heavy metals, was chosen for the study. Levels of Fe, Cr, Ni, Cd, Pb, Cu and Zn were determined in the soil and roots, rhizomes, stems and leaves of T. capensis from three Sites A, B and C polluted by effluent from a chrome ore processing plant, a gold ore processing plant, and a nickel ore processing plant, respectively. The levels of Cr were extremely high at Site A at 5415 and 786-16,047 μg g -1 dry weight in the soil and the plant, respectively, while the levels of Ni were high at Site C at 176 and 24-891 μg g -1 in the soil and the plant, respectively. The levels of Fe were high at all three sites at 2502-7500 and 906-13,833 μg g -1 in the soil and plant, respectively. For the rest of the metals, levels were modest at 8.5-148 and 2-264 μg g -1 in the soil and plant, respectively. Pearson's correlation analysis confirmed mutual synergistic metal-metal interactions in the uptake of Zn, Cu, Co, Ni, Fe, and Cr, which are attributed to the similarity in the radii and coordination geometry of the cations of these elements. The implications of such metal-metal interactions (or effects of one metal on the behaviour of another) on the uptake of Cr, a toxic element, and possible Cr detoxification mechanism within the plant, are discussed.

Heavy metals uptake by sonicated activated sludge: Relation with floc surface properties

International Nuclear Information System (INIS)

Laurent, Julien; Casellas, Magali; Dagot, Christophe

2009-01-01

The effects of sonication of activated sludge on heavy metal uptake were in a first time investigated in respect with potential modifications of floc surface properties. The treatment led to the simultaneous increase of specific surface area and of the availability of negative and/or hydrophilic sites. In parallel, organic matter was released in the soluble fraction. Sorption isotherms of cadmium and copper showed that uptake characteristics and mechanisms were highly dependent on both heavy metal species and specific energy supplied. The increase of both specific surface area and fixation sites availability led to the increase of Cd(II) uptake. For Cu(II), organic matter released in soluble phase during the treatment seemed to act as a ligand and to limit adsorption on flocs surface. Three different heavy metals uptake mechanisms have been identified: proton exchange, ion exchange and (co)precipitation

Uptake of americium-241 by algae and bacteria

Energy Technology Data Exchange (ETDEWEB)

Giesy, Jr, J P; Paine, D [Savannah River Ecology Lab., Aiken, S.C. (USA)

1978-01-01

The uptake of americium by three algae, Scenedesmus obliguus, Selenastrum capricomutum and Chlorella pyrenosdosa and a bacterium Aeromonas hydrophila was studied. Live and fixed cells of each algal species and live bacterial cells were used. It is shown that algae and bacteria concentrate americium 241 to a high degree which makes them important links in the biomagnification phenomenon which may ultimately lead to a human hazard and be potentially important in recycling Am /sup 241/ in the water column and mobilization from sediments. Chemical fixation of algal cells caused increased uptake which indicated that uptake is by passive diffusion and probably due to chemical alteration of surface binding sites.

P-EXAFS investigations of Zn uptake by montmorillonite. The strong and weak sites concept in the 2SPNE SC/CE sorption model

International Nuclear Information System (INIS)

Daehn, R.; Baeyens, B.; Bradbury, M.H.

2012-01-01

Document available in extended abstract form only. The sorption of radioactive elements on the immobile components in the near- and far-fields of a deep geological radioactive waste repository is a significant process in retarding their aqueous phase transport and an important component in safety assessment studies. The development of robust and well-founded mechanistic sorption models to predict the uptake of radionuclides under different geochemical conditions would enhance the justification and defensibility of the sorption values used in safety studies and thereby represent a considerable contribution to the scientific basis for radioactive waste disposal. The 2 site proto-lysis non electrostatic surface complexation and cation exchange (2SPNE SC/CE) sorption model has been used over the past decade or so to quantitatively describe the uptake of metals with oxidation states from II to VI on 2:1 clay minerals; montmorillonite and illite (Bradbury and Baeyens, 1997). One of the main features in this model is that there are two broad categories of amphoteric edge sorption sites; the so called strong (≡SSOH) and weak (≡SW1OH) sites. Because of their different sorption characteristics, it was expected that the coordination environments of the surface complexes on the two site types would be different. Although the 2SPNE SC/CE model uses different mechanistic uptake processes to describe sorption, it can only be described as a 'quasi mechanistic' model because the exact nature of the surface binding sites and surface complexes is not known. In order to check the 'strong site / weak site' sorption sites hypothesis in the 2SPNE SC/CE sorption model, it was essential to perform polarised extended X-ray absorption fine structure (P-EXAFS) measurements on an uptake system, in which it was possible to obtain good spectra particularly at the low metal loadings (∼2 mmol kg-1 or less) corresponding to occupancies dominated by strong sites. The Zn-montmorillonite system

Slitrk1-deficient mice display elevated anxiety-like behavior and noradrenergic abnormalities.

Science.gov (United States)

Katayama, K; Yamada, K; Ornthanalai, V G; Inoue, T; Ota, M; Murphy, N P; Aruga, J

2010-02-01

Mutations in SLITRK1 are found in patients with Tourette's syndrome and trichotillomania. SLITRK1 encodes a transmembrane protein containing leucine-rich repeats that is produced predominantly in the nervous system. However, the role of this protein is largely unknown, except that it can modulate neurite outgrowth in vitro. To clarify the role of Slitrk1 in vivo, we developed Slitrk1-knockout mice and analyzed their behavioral and neurochemical phenotypes. Slitrk1-deficient mice exhibited elevated anxiety-like behavior in the elevated plus-maze test as well as increased immobility time in forced swimming and tail suspension tests. Neurochemical analysis revealed that Slitrk1-knockout mice had increased levels of norepinephrine and its metabolite 3-methoxy-4-hydroxyphenylglycol. Administration of clonidine, an alpha2-adrenergic agonist that is frequently used to treat patients with Tourette's syndrome, attenuated the anxiety-like behavior of Slitrk1-deficient mice in the elevated plus-maze test. These results lead us to conclude that noradrenergic mechanisms are involved in the behavioral abnormalities of Slitrk1-deficient mice. Elevated anxiety due to Slitrk1 dysfunction may contribute to the pathogenesis of neuropsychiatric diseases such as Tourette's syndrome and trichotillomania.

Statins Promote Long-Term Recovery after Ischemic Stroke by Reconnecting Noradrenergic Neuronal Circuitry

Directory of Open Access Journals (Sweden)

Kyoung Joo Cho

2015-01-01

Full Text Available Inhibitors of HMG-CoA reductase (statins, widely used to lower cholesterol in coronary heart and vascular disease, are effective drugs in reducing the risk of stroke and improving its outcome in the long term. After ischemic stroke, cardiac autonomic dysfunction and psychological problems are common complications related to deficits in the noradrenergic (NA system. This study investigated the effects of statins on the recovery of NA neuron circuitry and its function after transient focal cerebral ischemia (tFCI. Using the wheat germ agglutinin (WGA transgene technique combined with the recombinant adenoviral vector system, NA-specific neuronal pathways were labeled, and were identified in the locus coeruleus (LC, where NA neurons originate. NA circuitry in the atorvastatin-treated group recovered faster than in the vehicle-treated group. The damaged NA circuitry was partly reorganized with the gradual recovery of autonomic dysfunction and neurobehavioral deficit. Newly proliferated cells might contribute to reorganizing NA neurons and lead anatomic and functional recovery of NA neurons. Statins may be implicated to play facilitating roles in the recovery of the NA neuron and its function.

Changes of the rats’ heart rate variability caused by chlorpromazine modulation of central noradrenergic neurotransmission during prolonged stress

Directory of Open Access Journals (Sweden)

O. Z. Мelnikova

2012-03-01

Full Text Available It’s established that under the prolonged stress there were changes of geometric and spectral indices of the rats’ heart rate variability (HRV, manifestations of which depended on duration of stressful factors acting and represented the stress reaction development from the stage of anxiety to the exhaustion phase. Application of chlorpromazine at the beginning and against the background of stress blocked the central alpha adrenoceptors and contributed to renewal of the most HRV indices into the limits of control values at the end of experiment. The results of research show that the modulation of functional state of central noradrenergic system plays a great role in the changes of HRV during prolonged stress.

FDG uptake in the fatty tissues of supraclavicular and the vascular structure of the lung hilum

International Nuclear Information System (INIS)

Dang Yaping; Liu Gang; Li Miao

2004-01-01

Objectives: To investigate FDG uptake on the sites of supraclavicular region (SR) and the lung hilum (LH) and find out the exact tissues of the uptake. Methods: Supraclavicular region (SR) and lung hilum (LH) are common sites for lymph node metastases. A commonly reported site of non-malignant FDG uptake on PET imaging in the SR is muscular uptake. PET/CT offers a unique technique to correlate PET findings with CT anatomy in the SR and EH. From September 2002 to March 2003, 147 consecutive clinical patients imaged by FDG PET/CT whole-body scan (GE Discovery LS, CT attenuation correction, OSEM reconstruction) were retrospectively reviewed. The presence of abnormal FDG uptake on PET images in the sites of SR and LH regions was evaluated and the corresponding CT findings on the same regions were also assessed. Results: Of 147 patients, 8 cases (2M, 6F and mean age 44 years) were found with increased symmetrical FDG uptake in the regions of the lower neck and shoulder as well as costo-vertebral articulations, the positive rates were 2.1% and 11.3 % for men and women respectively, and the average rate was 5.4%. However, no FDG uptake was seen in the greater muscular structures of the cervical or thoracic spine. FDG uptake was seen in the fatty tissue between the shoulder muscle and the dorsal thoracic wall, but not within the muscles itself. Five patients (3M, 2F, age 56-74 years,3.4%) showed abnormal LH FDG uptake, which were definitely localized in the vascular structure of the lung hilum by CT Conclusion: Co-registered PET/CT imaging shows that the FDG uptake been well known in the SR and LH regions are not fully located in greater muscular structures and lymph nodes, but in the costo-vertebral articulation complex of the thoracic spine and fatty tissue of the shoulders as well as in the vascular structure of both lung hilum. The FDG uptake in the fatty tissue of the shoulders was mostly seen in women, while the uptake in vascular structure of the lung hilum were

Dissociable roles of glucocorticoid and noradrenergic activation on social discounting.

Science.gov (United States)

Margittai, Zsofia; van Wingerden, Marijn; Schnitzler, Alfons; Joëls, Marian; Kalenscher, Tobias

2018-04-01

People often exhibit prosocial tendencies towards close kin and friends, but generosity decreases as a function of increasing social distance between donor and recipient, a phenomenon called social discounting. Evidence suggests that acute stress affects prosocial behaviour in general and social discounting in particular. We tested the causal role of the important stress neuromodulators cortisol (CORT) and noradrenaline (NA) in this effect by considering two competing hypotheses. On the one hand, it is possible that CORT and NA act in concert to increase generosity towards socially close others by reducing the aversiveness of the cost component in costly altruism and enhancing the emotional salience of vicarious reward. Alternatively, it is equally plausible that CORT and NA exert dissociable, opposing effects on prosocial behaviour based on prior findings implicating CORT in social affiliation, and NA in aggressive and antagonistic tendencies. We pharmacologically manipulated CORT and NA levels in a sample of men (N = 150) and found that isolated hydrocortisone administration promoted prosocial tendencies towards close others, reflected in an altered social discount function, but this effect was offset by concurrent noradrenergic activation brought about by simultaneous yohimbine administration. These results provide inceptive evidence for causal, opposing roles of these two important stress neuromodulators on prosocial behaviour, and give rise to the possibility that, depending on the neuroendocrine response profile, stress neuromodulator action can foster both tend-and-befriend and fight-or-flight tendencies at the same time. Copyright © 2018 Elsevier Ltd. All rights reserved.

Combining multiple ecosystem productivity measurements to constrain carbon uptake estimates in semiarid grasslands and shrublands

Science.gov (United States)

Maurer, G. E.; Krofcheck, D. J.; Collins, S. L.; Litvak, M. E.

2016-12-01

Recent observational and modeling studies have indicated that semiarid ecosystems are more dynamic contributors to the global carbon budget than once thought. Semiarid carbon fluxes, however, are generally small, with high interannual and spatial variability, which suggests that validating their global significance may depend on examining multiple productivity measures and their associated uncertainties and inconsistencies. We examined ecosystem productivity from eddy covariance (NEE), harvest (NPP), and terrestrial biome models (NEPm) at two very similar grassland sites and one creosote shrubland site in the Sevilleta National Wildlife Refuge of central New Mexico, USA. Our goal was to assess site and methodological correspondence in annual carbon uptake, patterns of interannual variability, and measurement uncertainty. One grassland site was a perennial carbon source losing 30 g C m-2 per year on average, while the other two sites were carbon sources or sinks depending on the year, with average net uptake of 5 and 25 g C m-2 per year at the grassland and shrubland site, respectively. Uncertainty values for cumulative annual NEE overlapped between the three sites in most years. When combined, aboveground and belowground annual NPP measurements were 15% higher than annual NEE values and did not confirm a loss of carbon at any site in any year. Despite differences in mean site carbon balance, year-to-year changes in cumulative annual NEE and NPP were similar at all sites with years 2010 and 2013 being favorable for carbon uptake and 2011 and 2012 being unfavorable at all sites. Modeled NEPm data for a number of nearby grid cells reproduced only a fraction of the observed range in carbon uptake and its interannual variability. These three sites are highly similar in location and climate and multiple carbon flux measurements confirm the high interannual variability in carbon flux. The exact magnitude of these fluxes, however, remains difficult to discern.

Spatial analysis of agri-environmental policy uptake and expenditure in Scotland.

Science.gov (United States)

Yang, Anastasia L; Rounsevell, Mark D A; Wilson, Ronald M; Haggett, Claire

2014-01-15

Agri-environment is one of the most widely supported rural development policy measures in Scotland in terms of number of participants and expenditure. It comprises 69 management options and sub-options that are delivered primarily through the competitive 'Rural Priorities scheme'. Understanding the spatial determinants of uptake and expenditure would assist policy-makers in guiding future policy targeting efforts for the rural environment. This study is unique in examining the spatial dependency and determinants of Scotland's agri-environmental measures and categorised options uptake and payments at the parish level. Spatial econometrics is applied to test the influence of 40 explanatory variables on farming characteristics, land capability, designated sites, accessibility and population. Results identified spatial dependency for each of the dependent variables, which supported the use of spatially-explicit models. The goodness of fit of the spatial models was better than for the aspatial regression models. There was also notable improvement in the models for participation compared with the models for expenditure. Furthermore a range of expected explanatory variables were found to be significant and varied according to the dependent variable used. The majority of models for both payment and uptake showed a significant positive relationship with SSSI (Sites of Special Scientific Interest), which are designated sites prioritised in Scottish policy. These results indicate that environmental targeting efforts by the government for AEP uptake in designated sites can be effective. However habitats outside of SSSI, termed here the 'wider countryside' may not be sufficiently competitive to receive funding in the current policy system. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ozone uptake, water loss and carbon exchange dynamics in annually drought-stressed Pinus ponderosa forests: measured trends and parameters for uptake modeling.

Science.gov (United States)

Panek, Jeanne A

2004-03-01

This paper describes 3 years of physiological measurements on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) growing along an ozone concentration gradient in the Sierra Nevada, California, including variables necessary to parameterize, validate and modify photosynthesis and stomatal conductance algorithms used to estimate ozone uptake. At all sites, gas exchange was under tight stomatal control during the growing season. Stomatal conductance was strongly correlated with leaf water potential (R2=0.82), which decreased over the growing season with decreasing soil water content (R2=0.60). Ozone uptake, carbon uptake, and transpirational water loss closely followed the dynamics of stomatal conductance. Peak ozone and CO2 uptake occurred in early summer and declined progressively thereafter. As a result, periods of maximum ozone uptake did not correspond to periods of peak ozone concentration, underscoring the inappropriateness of using current metrics based on concentration (e.g., SUM0, W126 and AOT40) for assessing ozone exposure risk to plants in this climate region. Both Jmax (maximum CO2-saturated photosynthetic rate, limited by electron transport) and Vcmax (maximum rate of Rubisco-limited carboxylation) increased toward the middle of the growing season, then decreased in September. Intrinsic water-use efficiency rose with increasing drought stress, as expected. The ratio of Jmax to Vcmax was similar to literature values of 2.0. Nighttime respiration followed a Q10 of 2.0, but was significantly higher at the high-ozone site. Respiration rates decreased by the end of the summer as a result of decreased metabolic activity and carbon stores.

Sympathetic ingrowth: A result of cholinergic nerve injury in the adult mammalian brain

International Nuclear Information System (INIS)

Davis, J.N.

1986-01-01

This paper describes sympathetic ingrowth, its regulation and function. The study leads to a better understanding of the molecular mechanisms that probably underlie the regulation of other neuronal rearrangements. The authors examine tritium-2-deoxyglucose uptake in the hippocampal formation after septal leasions. Preliminary experiments suggest that the septo-hippocampal fibers do influence tritium-2-deoxyglucose uptake throughout the hippocampal formation in normal animals. If sympathetic ingrowth also can influence this uptake, this could provide further evidence for an adaptive role of this noradrenergic replacement of cholinergic neurons

Glucocorticoids interact with the noradrenergic arousal system in the nucleus accumbens shell to enhance memory consolidation of both appetitive and aversive taste learning.

Science.gov (United States)

Wichmann, Romy; Fornari, Raquel V; Roozendaal, Benno

2012-09-01

It is well established that glucocorticoid hormones strengthen the consolidation of long-term memory of emotionally arousing experiences but have little effect on memory of low-arousing experiences. Although both positive and negative emotionally arousing events tend to be well remembered, studies investigating the neural mechanism underlying glucocorticoid-induced memory enhancement focused primarily on negatively motivated training experiences. In the present study we show an involvement of glucocorticoids within the nucleus accumbens (NAc) in enhancing memory consolidation of both an appetitive and aversive form of taste learning. The specific glucocorticoid receptor (GR) agonist RU 28362 (1 or 3ng) administered bilaterally into the NAc shell, but not core, of male Sprague-Dawley rats immediately after an appetitive saccharin drinking experience dose-dependently enhanced 24-h retention of the safe taste, resulting in a facilitated attenuation of neophobia. Similarly, GR agonist infusions given into the NAc shell immediately after pairing of the saccharin taste with a malaise-inducing agent enhanced memory of this negative experience, resulting in an intensified conditioned aversion. Importantly, a suppression of noradrenergic activity within the NAc shell with the β-adrenoceptor antagonist propranolol blocked the facilitating effect of a concurrently administered GR agonist on memory consolidation in both the appetitive and aversive learning task. Thus, these findings indicate that GR activation interacts with the noradrenergic arousal system within the NAc to enhance memory consolidation of emotionally arousing training experiences regardless of valence. Copyright © 2012 Elsevier Inc. All rights reserved.

Non-specific Inflammatory Disease Showed Abnormal FDG Uptake in Lower Extremities

International Nuclear Information System (INIS)

Chun, Kyung Ah; Kong, Eun Jung; Cho, Ihn Ho; Hong, Young Hoon; Lee, Choong Ki

2008-01-01

Including malignancy, various disease can show abnormal uptake in bone marrow. 1,2) We report a case of non-specific inflammatory FDG uptake in bone marrow mimicking malignancy. A 35-year old woman with fever of unknown origin (FUO) underwent 18 F-FDG PET/CT to find out fever focus and unknown malignancy. 18 F-FDG was injected and imaged 1hr after injection with Discovery ST (GE, USA). 18 F-FDG PET/CT whole body image showed abnormal uptake in lower extremities. MRI and biopsy was also done in the sites of abnormal uptake. PET and MRI suspect malignancy, but biopsy result was non-specific inflammatory process. The patient was improved her clinical condition after antibiotics therapy

Phosphorus deficiency enhances molybdenum uptake by tomato plants

International Nuclear Information System (INIS)

Heuwinkel, H.; Kirkby, E.A.; Le Bot, J.; Marschner, H.

1992-01-01

Water culture experiments are described which provide conclusive evidence that Mo uptake by tomato plants is markedly enhanced by P deficiency. In a longterm experiment, which ran for 11 days, in marked contrast to the uptake of other nutrients, a three fold higher Mo uptake rate was observed after only four days of withdrawal of P from the nutrient medium. In contrast to the gradual increase in pH of the nutrient medium of the plants supplied with P, the pH in the medium of the -P plants fell. Throughout the growth of these plants net H+ efflux could be accounted for by excess cation over anion uptake, indicating that organic acid extrusion plays no major role in the observed fall in pH. Further evidence that Mo uptake is enhanced in P deficient tomato plants is provided in short-term nutrient solution experiments (1h and 4h) using radioactive molybdenum (99Mo). Compared with P sufficient plants, the uptake rates of 99Mo by P deficient plants were three to five times higher after 1h and nine to twelve times higher after 4h. Resupplying P during the uptake periods to deficient plants reduced the uptake rate of 99Mo to values similar to those of P sufficient plants. It is concluded that the uptake of molybdate occurs via phosphate binding/ transporting sites at the plasma membrane of root cells. Further support for this conclusion comes from exchange experiments with non-labelled molybdenum, which show a much larger amount of 99Mo exchangeable from the roots of P deficient plants

Species turnover (β-diversity) in ectomycorrhizal fungi linked to NH4+ uptake capacity.

Science.gov (United States)

Kranabetter, J M; Hawkins, B J; Jones, M D; Robbins, S; Dyer, T; Li, T

2015-12-01

Ectomycorrhizal (EcM) fungal communities may be shaped by both deterministic and stochastic processes, potentially influencing ecosystem development and function. We evaluated community assembly processes for EcM fungi of Pseudotsuga menziesii among 12 sites up to 400 km apart in southwest British Columbia (Canada) by investigating species turnover (β-diversity) in relation to soil nitrogen (N) availability and physical distance. We then examined functional traits for an N-related niche by quantifying net fluxes of NH4+, NO3- and protons on excised root tips from three contrasting sites using a microelectrode ion flux measurement system. EcM fungal communities were well aligned with soil N availability and pH, with no effect of site proximity (distance-decay curve) on species assemblages. Species turnover was significant (β(1/2) = 1.48) along soil N gradients, with many more Tomentella species on high N than low N soils, in contrast to Cortinarius species. Ammonium uptake was greatest in the spring on the medium and rich sites and averaged over 190 nmol/m(2)/s for Tomentella species. The lowest uptake rates of NH4+ were by nonmycorrhizal roots of axenically grown seedlings (10 nmol/m(2)/s), followed by Cortinarius species (60 nmol/m(2)/s). EcM roots from all sites displayed only marginal uptake of nitrate (8.3 nmol/m(2)/s). These results suggest NH4+ uptake capacity is an important functional trait influencing the assembly of EcM fungal communities. The diversity of EcM fungal species across the region arguably provides critical belowground adaptations to organic and inorganic N supply that are integral to temperate rainforest ecology. © 2015 John Wiley & Sons Ltd.

Forest canopy uptake of atmospheric nitrogen deposition at eastern U.S. conifer sites: Carbon storage implications?

Science.gov (United States)

Herman Sievering; Ivan Fernandez; John Lee; John Hom; Lindsey Rustad

2000-01-01

Dry deposition determinations, along with wet deposition and throughfall (TF) measurements, at a spruce fir forest in central Maine were used to estimate the effect of atmospherically deposited nitrogen (N) uptake on forest carbon storage. Using nitric acid and particulate N as well as TF ammonium and nitrate data, the growing season (May-October) net canopy uptake of...

Correlation of leaf damage with uptake and translocation of glyphosate in velvetleaf (Abutilon theophrasti)

International Nuclear Information System (INIS)

Feng, P.C.C.; Ryerse, J.S.; Sammons, R.D.

1998-01-01

Uptake and translocation of glyphosate in three commercial formulations were examined in velvetleaf, a dicotyledonous weed that is commonly treated with glyphosate. The formulations included Roundup(R) (MON35085), Roundup Ultra, and Touchdown(R) as sold in Canada. A minimal amount of 14C-glyphosate was spiked into a lethal rate of each formulation, and the short-term (3 to 72 h) uptake into the treated leaf and subsequent translocation into the plant were measured. Time-course studies showed very rapid uptake and translocation of glyphosate in the Ultra formulation. In comparison, the uptake and translocation of glyphosate in Touchdown was much slower but continued throughout the 72-h period. Glyphosate in the Roundup formulation showed intermediate uptake and translocation. Tissue necrosis at the application sites of Ultra and Roundup was visible within 24 h after treatment. Examinations using stereo and fluorescence microscopy revealed extensive cell death and tissue disruption. Tissue necrosis from Ultra and Roundup was also observed in blank formulations containing no glyphosate and therefore was likely caused by the surfactants. In contrast, the application sites of Touchdown produced little to no leaf damage. Our results demonstrated a direct correlation between tissue necrosis and rapid rates of glyphosate uptake and translocation. (author)

A Universal Isotherm Model to Capture Adsorption Uptake and Energy Distribution of Porous Heterogeneous Surface

KAUST Repository

Ng, Kim Choon; Burhan, Muhammad; Shahzad, Muhammad Wakil; Ismail, Azahar Bin

2017-01-01

The adsorbate-adsorbent thermodynamics are complex as it is influenced by the pore size distributions, surface heterogeneity and site energy distribution, as well as the adsorbate properties. Together, these parameters defined the adsorbate uptake forming the state diagrams, known as the adsorption isotherms, when the sorption site energy on the pore surfaces are favorable. The available adsorption models for describing the vapor uptake or isotherms, hitherto, are individually defined to correlate to a certain type of isotherm patterns. There is yet a universal approach in developing these isotherm models. In this paper, we demonstrate that the characteristics of all sorption isotherm types can be succinctly unified by a revised Langmuir model when merged with the concepts of Homotattic Patch Approximation (HPA) and the availability of multiple sets of site energy accompanied by their respective fractional probability factors. The total uptake (q/q*) at assorted pressure ratios (P/P s ) are inextricably traced to the manner the site energies are spread, either naturally or engineered by scientists, over and across the heterogeneous surfaces. An insight to the porous heterogeneous surface characteristics, in terms of adsorption site availability has been presented, describing the unique behavior of each isotherm type.

A Universal Isotherm Model to Capture Adsorption Uptake and Energy Distribution of Porous Heterogeneous Surface

KAUST Repository

Ng, Kim Choon

2017-08-31

The adsorbate-adsorbent thermodynamics are complex as it is influenced by the pore size distributions, surface heterogeneity and site energy distribution, as well as the adsorbate properties. Together, these parameters defined the adsorbate uptake forming the state diagrams, known as the adsorption isotherms, when the sorption site energy on the pore surfaces are favorable. The available adsorption models for describing the vapor uptake or isotherms, hitherto, are individually defined to correlate to a certain type of isotherm patterns. There is yet a universal approach in developing these isotherm models. In this paper, we demonstrate that the characteristics of all sorption isotherm types can be succinctly unified by a revised Langmuir model when merged with the concepts of Homotattic Patch Approximation (HPA) and the availability of multiple sets of site energy accompanied by their respective fractional probability factors. The total uptake (q/q*) at assorted pressure ratios (P/P s ) are inextricably traced to the manner the site energies are spread, either naturally or engineered by scientists, over and across the heterogeneous surfaces. An insight to the porous heterogeneous surface characteristics, in terms of adsorption site availability has been presented, describing the unique behavior of each isotherm type.

`Six of the best`: intramuscular uptake of {sup 99m}Tc HDP revisited in sites of i.m. Administrations for pain relief medication

Energy Technology Data Exchange (ETDEWEB)

Richards, P.A.C. [Launceston General Hospital, TAS (Australia). Department of Nuclear Medicine

1998-03-01

Full text: It is not uncommon at sites of intramuscular (i.m.) administration for pain relieving drugs, that intravenously administered {sup 99T}c-HDP for skeletal imaging will localize at some sites. It is important, however, if such sites overlie bone that the possibility of including such areas in the diagnosis is of concern, and under such circumstances either planar or SPECT imaging will differentiate the site from bone or tissue uptake. There have been many situations reported where such localisation can occur, but it is generally believed that in the majority of cases this is entirely due to the presence of local microcalcification. The study was conducted to elucidate whether there was any relationship between physical trauma, osmolality, drug, dose, volume or repetitiveness of administrations in the extra-skeletal localizations of {sup 99m}Tc-HDP in patients presenting for whole body bone scans. It is concluded that physical trauma plays a significant role in the localisation of {sup 99m}Tc-HDP as cell Iysis leads to the formation of ``dense bodies`` in the mitochondria. These bodies occur when excess calcium combines with phosphate ions under circumstances of cellular disorganisation and trauma.

Opioid and noradrenergic contributions of tapentadol to the inhibition of locus coeruleus neurons in the streptozotocin rat model of polyneuropathic pain.

Science.gov (United States)

Torres-Sanchez, Sonia; Borges, Gisela Da Silva; Mico, Juan A; Berrocoso, Esther

2018-06-01

Tapentadol is an analgesic that acts as an agonist of µ opioid receptors (MOR) and that inhibits noradrenaline reuptake. Data from healthy rats show that tapentadol inhibits neuronal activity in the locus coeruleus (LC), a nucleus regulated by both the noradrenergic and opioid systems. Thus, we set out to investigate the effect of tapentadol on LC activity in streptozotocin (STZ)-induced diabetic rats, a model of diabetic polyneuropathy, by analyzing single-unit extracellular recordings of LC neurons. Four weeks after inducing diabetes, tapentadol dose-response curves were obtained from animals pre-treated with RX821002 or naloxone (alpha2-adrenoceptors and opioid receptors antagonists, respectively). In STZ rats, the spontaneous activity of LC neurons (0.9 ± 0.1 Hz) was lower than in naïve animals (1.5 ± 0.1 Hz), and tapentadol's inhibitory effect was also weaker. Alpha2-adrenoceptors blockade by RX821002 (100 μg/kg i.v.) in STZ animals significantly increased the spontaneous activity (from 0.8 ± 0.1 to 1.4 ± 0.2 Hz) and it dampened the inhibition of LC neurons produced by tapentadol. However, opioid receptors blockade following naloxone pre-treatment (5 mg/kg i.v.) did not alter the spontaneous firing rate (0.9 ± 0.2 vs 0.9 ± 0.2 Hz) or the inhibitory effect of tapentadol on LC neurons in STZ animals. Thus, diabetic polyneuropathy appears to exert neuroplastic changes in LC neurotransmission, enhancing the sensitivity of alpha2-adrenoceptors and dampening opioid receptors expression. Tapentadol's activity seems to be predominantly mediated through its noradrenergic effects rather than its influence on opioid receptors in the STZ model of diabetic polyneuropathy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of the noradrenergic pathway and alpha-2 and beta-receptors in the modulation of the analgesia induced by transcutaneous electric nerve stimulation of high and low frequencies

OpenAIRE

Vasconcellos, Thiago Henrique Ferreira; Pantaleão, Patricia de Fátima; Teixeira, Dulcinéa Gonçalves; Santos, Ana Paula; Ferreira, Célio Marcos dos Reis

2014-01-01

Transcutaneous electric nerve stimulation is a noninvasive method used in clinical Physiotherapy to control acute or chronic pain. Different theories have been proposed to explain the mechanism of the analgesic action of transcutaneous electric nerve stimulation, as the participation of central and peripheral neurotransmitters. The aim of this study was to evaluate the involvement of noradrenergic pathway and of the receptors alfa-2 and beta in the modulation of analgesia produced by transcut...

Compost amendment, enhanced nutrient uptake and dry matter ...

African Journals Online (AJOL)

Field trial was conducted to assess the influence of Compost and inorganic fertilizer as well as plant growth stage on growth, nutrient uptake, dry matter accumulation and partitioning in maize crop grown on the battery waste contaminated site. Two types of compost (Mexican Sunflower (MSC) and Cassava peels (CPC) ...

Chronic treatment with prazosin or duloxetine lessens concurrent anxiety-like behavior and alcohol intake: evidence of disrupted noradrenergic signaling in anxiety-related alcohol use.

Science.gov (United States)

Skelly, Mary J; Weiner, Jeff L

2014-07-01

Alcohol use disorders have been linked to increased anxiety, and enhanced central noradrenergic signaling may partly explain this relationship. Pharmacological interventions believed to reduce the excitatory effects of norepinephrine have proven effective in attenuating ethanol intake in alcoholics as well as in rodent models of ethanol dependence. However, most preclinical investigations into the effectiveness of these drugs in decreasing ethanol intake have been limited to acute observations, and none have concurrently assessed their anxiolytic effects. The purpose of these studies was to examine the long-term effectiveness of pharmacological interventions presumed to decrease norepinephrine signaling on concomitant ethanol self-administration and anxiety-like behavior in adult rats with relatively high levels of antecedent anxiety-like behavior. Adult male Long-Evans rats self-administered ethanol on an intermittent access schedule for eight to ten weeks prior to being implanted with osmotic minipumps containing either an a1-adrenoreceptor antagonist (prazosin, 1.5 mg/kg/day), a β1/2-adrenoreceptor antagonist (propranolol, 2.5 mg/kg/day), a serotonin/norepinephrine reuptake inhibitor (duloxetine, 1.5 mg/kg/day) or vehicle (10% dimethyl sulfoxide). These drugs were continuously delivered across four weeks, during which animals continued to have intermittent access to ethanol. Anxiety-like behavior was assessed on the elevated plus maze before treatment and again near the end of the drug delivery period. Our results indicate that chronic treatment with a low dose of prazosin or duloxetine significantly decreases ethanol self-administration (P chronic treatment with putative inhibitors of central noradrenergic signaling may attenuate ethanol intake via a reduction in anxiety-like behavior.

Research on the uptake of technetium-labelled dimercaptosuccinic acid

International Nuclear Information System (INIS)

Moretti, J.L.; Dumery, J.P.; Meignan, M.; Wirquin, E.; Escaig, F.; Galle, P.

1976-01-01

Owing to the relatively strong urinary excretion of DMSA (20 to 25% of the injected dose in 24 hours) its renal uptake values are only truly significant in the absence of a urine retention syndrome which is detected by a previous study with sup(99m)Tc DTPA. In other cases the uptake measurement can be used to judge the functional value of each kidney separately and to estimate loss of functional capacity and compensative hypertrophies. For all the diseases explored the results obtained agree well with those of other functional explorations (creatinine clearance, separate urinary urea concentration). Moreover DMSA gives results similar to those obtained with mercury chloride. Neither its intrarenal metabolism nor its exact intracellular uptake site are yet known. A fuller knowledge of these points should improve the interpretation of the results [fr

Correlation between (3H)dopamine specific uptake and (3H)GBR 12783 specific binding during the maturation of rat striatum

International Nuclear Information System (INIS)

Bonnet, J.J.; Costentin, J.

1989-01-01

The development of the specific uptake of dopamine in the rat striatum during the early postnatal period is compared with the ontogenetic changes of the specific binding of ( 3 H)GBR 12783 to the site of uptake inhibition. During maturation, the increase in the specific binding of ( 3 H)GBR 12783 parallels the increase in the specific uptake of dopamine. ( 3 H)GBR 12783 specific binding sites increase in number from day 1 postpartum until 40 days, when they reach the adult level. In 40 day-old rats, the weight of the striatum represents 80% of adult values. The affinity of ( 3 H)GBR 12783 for the inhibition site is similar in membrane preparations obtained from 6 day-old pups and adults; this results in a same ability of the inhibitor to block the specific uptake of dopamine into synaptosomes obtained from pups or adult rats. These data support the hypothesis of the existence of a single molecular entity including both the inhibition site and the carrier itself

Factors influencing uptake of sylvatic plague vaccine baits by prairie dogs

Science.gov (United States)

Abbott, Rachel C.; Russell, Robin E.; Richgels, Katherine; Tripp, Daniel W.; Matchett, Marc R.; Biggins, Dean E.; Rocke, Tonie E.

2017-01-01

Sylvatic plague vaccine (SPV) is a virally vectored bait-delivered vaccine expressing Yersinia pestis antigens that can protect prairie dogs (Cynomys spp.) from plague and has potential utility as a management tool. In a large-scale 3-year field trial, SPV-laden baits containing the biomarker rhodamine B (used to determine bait consumption) were distributed annually at a rate of approximately 100–125 baits/hectare along transects at 58 plots encompassing the geographic ranges of four species of prairie dogs. We assessed site- and individual-level factors related to bait uptake in prairie dogs to determine which were associated with bait uptake rates. Overall bait uptake for 7820 prairie dogs sampled was 70% (95% C.I. 69.9–72.0). Factors influencing bait uptake rates by prairie dogs varied by species, however, in general, heavier animals had greater bait uptake rates. Vegetation quality and day of baiting influenced this relationship for black-tailed, Gunnison’s, and Utah prairie dogs. For these species, baiting later in the season, when normalized difference vegetation indices (a measure of green vegetation density) are lower, improves bait uptake by smaller animals. Consideration of these factors can aid in the development of species-specific SPV baiting strategies that maximize bait uptake and subsequent immunization of prairie dogs against plague.

An improved automated synthesis and in vivo evaluation of PET radioligand for serotonin re-uptake sites. [11C]McN5652X

International Nuclear Information System (INIS)

Sasaki, Masahiro; Suhara, Tetsuya; Suzuki, Kazutoshi; Kubodera, Akiko.

1996-01-01

Carbon-11 labeled serotonin (5-HT) re-uptake inhibitor, [ 11 C]McN5 652X ((6S,10bR)-trans-( + )-1,2,3,5,6,10b-hexahydro-6-[4-(methylthio)phenyl]pyrrolo-[2,1-a]-isoquinoline), has recently been reported to be favorable for studying human 5-HT re-uptake site by positron emission tomography (PET) because of its rapid and high specific binding characteristics as radioligands. [ 11 C]McN5652X has been synthesized by S-methylation of the corresponding des-methyl precursor A with [ 11 C]iodomethane. One serious disadvantage of this procedure, however, is the lack of stability of A. The improved method for the synthesis of A has been desired. We have found that the decomposition of A is significantly reduced by adding a protecting agent for SH groups, dithiothreitol (DTT), into the reaction medium immediately after the demethylation of McN5652X. By using this stabilized precursor A, we have developed an automated procedure giving [ 11 C]McN5652X with 98.6±0.4% radiochemical purity in high specific activity (181.3±7.4GBq/μmol). Preclinical evaluation of the produ ct was carried out by injecting the solution of [ 11 C]McN5652X obtained by this procedure into mice. [ 11 C]McN5652X showed the high accumulation into mouse thalamus, striatum and cerebral cortex, organs known to have high level of 5-HT receptor density, after intravenous injection. Human PET studies also showed the high uptakes of this radioligand into the thalamus, striatum and midbrain

Characterization of dietary Ni uptake in the rainbow trout, Oncorhynchus mykiss.

Science.gov (United States)

Leonard, Erin M; Nadella, Sunita R; Bucking, Carol; Wood, Chris M

2009-07-26

We characterized dietary Ni uptake in the gastrointestinal tract of rainbow trout using both in vivo and in vitro techniques. Adult trout were fed a meal (3% of body mass) of uncontaminated commercial trout chow, labeled with an inert marker (ballotini beads). In vivo dietary Ni concentrations in the supernatant (fluid phase) of the gut contents averaged from 2 micromoll(-1) to 24 micromoll(-1), and net overall absorption efficiency of dietary Ni was approximately 50% from the single meal, similar to that for the essential metal Cu, adding to the growing evidence of Ni essentiality. The stomach and mid-intestine emerged as important sites of Ni uptake in vivo, accounting for 78.5% and 18.9% of net absorption respectively, while the anterior intestine was a site of net secretion. Most of the stomach uptake occurred in the first 4h. In vitro gut sac studies using radiolabeled Ni (at 30 micromoll(-1)) demonstrated that unidirectional uptake occurred in all segments, with area-weighted rates being highest in the anterior intestine. Differences between in vivo and in vitro results likely reflect the favourable uptake conditions in the stomach, and biliary secretion of Ni in the anterior intestine in vivo. The concentration-dependent kinetics of unidirectional Ni uptake in vitro were biphasic in nature, with a saturable Michaelis-Menten relationship observed at 1-30 micromoll(-1) Ni (K(m) - 11 micromoll(-1), J(max) - 53 pmolcm(-2)h(-1) in the stomach and K(m) - 42 micromoll(-1), J(max) - 215 pmolcm(-2)h(-1) in the mid-intestine), suggesting mediation by a channel or carrier process. A linear uptake relationship was seen at higher concentrations, indicative of simple diffusion. Ni uptake (at 30 micromoll(-1)) into the blood compartment was significantly reduced in the stomach by high Mg (50 mmoll(-1)), and in the mid-intestine by both Mg (50 mmoll(-1)) and Ca (50 mmoll(-1)). In both regions, kinetic analysis demonstrated reductions in J(max) with unchanged K

Laminar pattern of cholinergic and adrenergic receptors in rat visual cortex using quantitative receptor autoradiography

International Nuclear Information System (INIS)

Schliebs, R.; Walch, C.

1989-01-01

The laminar distribution of muscarinic acetylcholine receptors, including the M1-receptor subtype, of beta-adrenergic receptors, and noradrenaline uptake sites, was studied in the adult rat visual, frontal, somatosensory and motor cortex, using quantitative receptor autoradiography. In the visual cortex, the highest density of muscarinic acetylcholine receptors was found in layer I. From layer II/III to layer V binding decreases continueously reaching a constant binding level in layers V and VI. This laminar pattern of muscarinic receptor density differs somewhat from that observed in the non-visual cortical regions examined: layer II/III contained the highest receptor density followed by layer I and IV: lowest density was found in layer V and VI. The binding profile of the muscarinic cholinergic M1-subtype through the visual cortex shows a peak in cortical layer II and in the upper part of layer VI, whereas in the non-visual cortical regions cited the binding level was high in layer II/III, moderate in layer I and IV, and low in layer VI. Layers I to IV of the visual cortex contained the highest beta-adrenergic receptor densities, whereas only low binding levels were observed in the deeper layers. A similar laminar distribution was found also in the frontal, somatosensory and motor cortex. The density of noradrenaline uptake sites was high in all layers of the cortical regions studied, but with noradrenaline uptake sites somewhat more concentrated in the superficial layers than in deeper ones. The distinct laminar pattern of cholinergic and noradrenergic receptor sites indicates a different role for acetylcholine and noradrenaline in the functional anatomy of the cerebral cortex, and in particular, the visual cortex. (author)

Laminar pattern of cholinergic and adrenergic receptors in rat visual cortex using quantitative receptor autoradiography

Energy Technology Data Exchange (ETDEWEB)

Schliebs, R; Walch, C [Leipzig Univ. (German Democratic Republic). Bereich Medizin; Stewart, M G [Open Univ., Milton Keynes (UK)

1989-01-01

The laminar distribution of muscarinic acetylcholine receptors, including the M1-receptor subtype, of beta-adrenergic receptors, and noradrenaline uptake sites, was studied in the adult rat visual, frontal, somatosensory and motor cortex, using quantitative receptor autoradiography. In the visual cortex, the highest density of muscarinic acetylcholine receptors was found in layer I. From layer II/III to layer V binding decreases continueously reaching a constant binding level in layers V and VI. This laminar pattern of muscarinic receptor density differs somewhat from that observed in the non-visual cortical regions examined: layer II/III contained the highest receptor density followed by layer I and IV: lowest density was found in layer V and VI. The binding profile of the muscarinic cholinergic M1-subtype through the visual cortex shows a peak in cortical layer II and in the upper part of layer VI, whereas in the non-visual cortical regions cited the binding level was high in layer II/III, moderate in layer I and IV, and low in layer VI. Layers I to IV of the visual cortex contained the highest beta-adrenergic receptor densities, whereas only low binding levels were observed in the deeper layers. A similar laminar distribution was found also in the frontal, somatosensory and motor cortex. The density of noradrenaline uptake sites was high in all layers of the cortical regions studied, but with noradrenaline uptake sites somewhat more concentrated in the superficial layers than in deeper ones. The distinct laminar pattern of cholinergic and noradrenergic receptor sites indicates a different role for acetylcholine and noradrenaline in the functional anatomy of the cerebral cortex, and in particular, the visual cortex. (author).

Tumor grade-related thallium-201 uptake in chondrosarcomas

International Nuclear Information System (INIS)

Kaya, G.C.; Demir, Y.; Ozkal, S.

2010-01-01

Diagnosis of low-grade chondrosarcoma, especially discrimination between enchondroma and low-grade chondrosarcoma, may be difficult pathologically. The aim of this study was to evaluate the value of thallium-201 (Tl-201) scintigraphy in the diagnosis of chondrosarcoma and to investigate whether there was a correlation between Tl-201 uptake and tumor grade. We retrospectively evaluated 121 patients with pathologically proven bone and soft tissue tumors diagnosed between the years 1999 and 2007. All patients were followed by the Bone and Soft Tissue Tumor Working Group in our hospital. Twenty-three patients, mean age 44±15 (range 17-72) years, with a diagnosis of cartilaginous tumors were included. Increased Tl-201 uptake at the lesion sites greater than background was evaluated as malignant tumor. For the pathologic classification, a grading system (grade 1-3) based on the histopathologic findings was used. Pearson correlation coefficient was used to determine whether there was any correlation between Tl-201 uptake and tumor grade in chondrosarcoma. There were 7 enchondromas and 16 chondrosarcomas. Four of 16 patients with chondrosarcoma had lesions pathologically classified as grade 3, 5 as grade 2, and 7 had grade 1 chondrosarcoma. Increased Tl-201 uptake was observed in all patients with grade 3 chondrosarcoma and 2 patients with grade 2 chondrosarcoma. Of 10 patients with chondrosarcoma, 3 grade 2 chondrosarcomas and 7 grade 1 chondrosarcomas, there was no Tl-201 uptake in the tumor region. A significant correlation was found between Tl-201 uptake and tumor grade in chondrosarcoma (p=0.002, r=0.71). Only a few reports in literature have demonstrated false negative results in low-grade chondrosarcoma. Tl-201 uptake was related to tumor grade in chondrosarcoma. If there is a possibility of chondrosarcoma, Tl-201 scintigraphy should be reported with caution. (author)

Nitrogen and Phosphorus Plant Uptake During Periods with no Photosynthesis Accounts for About Half of Global Annual Uptake

Science.gov (United States)

Riley, W. J.; Zhu, Q.; Tang, J.

2017-12-01

Uncertainties in current Earth System Model (ESM) predictions of terrestrial carbon-climate feedbacks over the 21st century are as large as, or larger than, any other reported natural system uncertainties. Soil Organic Matter (SOM) decomposition and photosynthesis, the dominant fluxes in this regard, are tightly linked through nutrient availability, and the recent Coupled Model Inter-comparison Project 5 (CMIP5) used for climate change assessment had no credible representations of these constraints. In response, many ESM land models (ESMLMs) have developed dynamic and coupled soil and plant nutrient cycles. Here we quantify terrestrial carbon cycle impacts from well-known observed plant nutrient uptake mechanisms ignored in most current ESMLMs. In particular, we estimate the global role of plant root nutrient competition with microbes and abiotic process at night and during the non-growing season using the ACME land model (ALMv1-ECA-CNP) that explicitly represents these dynamics. We first demonstrate that short-term nutrient uptake dynamics and competition between plants and microbes are accurately predicted by the model compared to 15N and 33P isotopic tracer measurements from more than 20 sites. We then show that global nighttime and non-growing season nitrogen and phosphorus uptake accounts for 46 and 45%, respectively, of annual uptake, with large latitudinal variation. Model experiments show that ignoring these plant uptake periods leads to large positive biases in annual N leaching (globally 58%) and N2O emissions (globally 68%). Biases these large will affect modeled carbon cycle dynamics over time, and lead to predictions of ecosystems that have overly open nutrient cycles and therefore lower capacity to sequester carbon.

The other face of depression, reduced positive affect: the role of catecholamines in causation and cure.

Science.gov (United States)

Nutt, David; Demyttenaere, Koen; Janka, Zoltan; Aarre, Trond; Bourin, Michel; Canonico, Pier Luigi; Carrasco, Jose Luis; Stahl, Steven

2007-07-01

Despite significant advances in pharmacologic therapy of depression over the past two decades, a substantial proportion of patients fail to respond or experience only partial response to serotonin re-uptake inhibitor antidepressants, resulting in chronic functional impairment. There appears to be a pattern of symptoms that are inadequately addressed by serotonergic antidepressants - loss of pleasure, loss of interest, fatigue and loss of energy. These symptoms are key to the maintenance of drive and motivation. Although these symptoms are variously defined, they are consistent with the concept of ;decreased positive affect'. Positive affect subsumes a broad range of positive mood states, including feelings of happiness (joy), interest, energy, enthusiasm, alertness and self-confidence. Although preliminary, there is evidence to suggest that antidepressants that enhance noradrenergic and dopaminergic activity may afford a therapeutic advantage over serotonergic antidepressants in the treatment of symptoms associated with a reduction in positive affect. Dopaminergic and noradrenergic agents, including the dual acting norepinephrine and dopamine re-uptake inhibitors, have demonstrated antidepressant activity in the absence of serotonergic function, showing similar efficacy to both tricyclic and serotonin re-uptake inhibitor antidepressants. Moreover, the norepinephrine and dopamine re-uptake inhibitor bupropion has been shown to significantly improve symptoms of energy, pleasure and interest in patients with depression with predominant baseline symptoms of decreased pleasure, interest and energy. Focusing treatment on the predominant or driving symptomatology for an individual patient with major depression could potentially improve rates of response and remission.

Constraining water uptake depths in semiarid environments using water stable isotopes

Science.gov (United States)

Beyer, Matthias; Königer, Paul; Himmelsbach, Thomas

2017-04-01

The biophysical process of transpiration recently received increased attention by ecohydrologists as it has been proven the largest flux of the global water balance. However, fundamental aspects related to the questions how and from which sources plants receive their water are not fully understood. Especially the process of plant water uptake from deeper soil and its impact on the water balance requires increased scientific effort. In this study we combined tracer experiments with the analysis of natural isotopic compositions in order to: i) derive a suitable site-specific root water uptake distribution for hydrological modeling; ii) find indicators for groundwater use by specific plants; and iii) evaluate the importance of deep unsaturated zone water uptake using HYDRUS 1D. The bayesian mixing model MixSIAR was applied at a semiarid site with a deep unsaturated zone in northern Namibia in order to identify source water contributions of the most abundant species (A.erioloba, B.plurijuga, C.collinum, S.luebertii and T.sericea). In addition, a previously developed method for the investigation of root water uptake depths based on deuterium labeling (2H2O) at specific depths (0.5 to 4 m) and monitoring of tracer uptake by plants was carried out with a focus on the deeper unsaturated zone. With the experimental results a root water uptake distribution for the lateral root zone was derived which allows to constrain the source water contributions estimated with MixSIAR. Finally, a HYDRUS 1D model was established and unsaturated zone water transport was evaluated. The analysis of the natural isotopic compositions reveals a significant contribution of groundwater (median: 48%) to the isotopic composition of A.erioloba at the end of the dry season indicating the presence of deep tap roots for a number of individuals. All other investigated species obtain their water from the shallow (median: 22%) or deeper (median: 62%) unsaturated zone at this time of the year. The water

The MDP skull uptake test: A new diagnostic tool

International Nuclear Information System (INIS)

Ell, P.J.; Jarritt, P.H.; Cullum, I.; Lui, D.

1984-01-01

An original approach to the measurement of bone turnover is presented. With SPECT, the authors have measured in pgr/ml, the uptake of MDP by the skull in man. The Cleon 710 scanner, ring phantoms and bone biopsies were used for ultimate in vivo/in vitro count recovery correlation and calibration. A normal range for 24 patients was found: 8.5 to 19.5 pgr/ml with a mean of 14. For patients with bony metastases (12), the values were: 22.5 to 50, mean of 30. For 5 patients with osteomalacia, the values were 46 to 68, mean of 62: for 12 patients with hyperparathyroidism, the values were 37 to 48.5, mean of 43. In 3 patients with Pagets disease, the values were 58.5 to 75, with a mean of 65. In 76 patients with metastatic disease to bone, the conventional wholebody bone scan was investigated against the following: 24h wholebody retention of MDP (WBR), skull uptake as described and GFR by Cr-51-DTPA. There is a correlation between GFR and WBR - r=0.67. There is a lesser correlation between GFR and skull uptake - r=0.3. There is no correlation between skull uptake and WBR - r=0.1. The comparison of skull uptake data with normal whole body bone scans leads to a significant proportion of cancer patients with positive skull uptake data. Monostotic disease (especially if metabolic in nature) expresses itself by abnormal skull uptake even if the clinical site of abnormality lies outside the skull. This new technique is ideal as a tool to investigate phosphonate concentration in bone. With it, the authors have shown the effect of specific activity of label on skull uptake, which increases as the specific activity of labelled MDP decreases

The Global Influence of Cloud Optical Thickness on Terrestrial Carbon Uptake

Science.gov (United States)

Zhu, P.; Cheng, S. J.; Keppel-Aleks, G.; Butterfield, Z.; Steiner, A. L.

2016-12-01

Clouds play a critical role in regulating Earth's climate. One important way is by changing the type and intensity of solar radiation reaching the Earth's surface, which impacts plant photosynthesis. Specifically, the presence of clouds modifies photosynthesis rates by influencing the amount of diffuse radiation as well as the spectral distribution of solar radiation. Satellite-derived cloud optical thickness (COT) may provide the observational constraint necessary to assess the role of clouds on ecosystems and terrestrial carbon uptake across the globe. Previous studies using ground-based observations at individual sites suggest that below a COT of 7, there is a greater increase in light use efficiency than at higher COT values, providing evidence for higher carbon uptake rates than expected given the reduction in radiation by clouds. However, the strength of the COT-terrestrial carbon uptake correlation across the globe remains unknown. In this study, we investigate the influence of COT on terrestrial carbon uptake on a global scale, which may provide insights into cloud conditions favorable for plant photosynthesis and improve our estimates of the land carbon sink. Global satellite-derived MODIS data show that tropical and subtropical regions tend to have COT values around or below the threshold during growing seasons. We find weak correlations between COT and GPP with Fluxnet MTE global GPP data, which may be due to the uncertainty of upscaling GPP from individual site measurements. Analysis with solar-induced fluorescence (SIF) as a proxy for GPP is also evaluated. Overall, this work constructs a global picture of the role of COT on terrestrial carbon uptake, including its temporal and spatial variations.

Characterisation of citrate and iron citrate uptake by cultured rat hepatocytes

International Nuclear Information System (INIS)

Graham, R.M.; Morgan, E.H.; Baker, E.

1998-01-01

Background/Aims: the endogenous low molecular weight iron chelator, citrate, is considered to be an important contributor to iron transport and the liver the main site of uptake of iron citrate in subjects suffering from diseases of iron overload. Moreover, the citrate-metabolising enzyme, aconitase, is implicated in the regulation of cellular iron metabolism. This study was undertaken to determine the role of citrate and ferric citrate in the uptake of iron by rat hepatocytes. Methods: Cultured rat hepatocytes were incubated (37 deg. C, 15 min) with 100 μM [ 14 C]-citrate in the presence or absence of 1.0 μM 55 Fe. Membrane-bound and intracellular radiolabel were separated by incubation with the general protease, Pronase. Results: Our results suggest that ferric citrate uptake is mediated by a specific citrate binding site which exhibits a higher affinity for citrate in the presence of iron than in its absence. Citrate was internalised by hepatocytes, with at least 70% being oxidised to CO 2 within 15 min. Citrate uptake was pH-dependent, did not require the presence of sodium and increased with increasing iron concentration. Metabolic energy, anion channels, the Na + , K + -ATPase and vesicle acidification do not appear to play a role in uptake of ferric citrate, but functional sulphydryl groups may be involved. Conclusions: The data suggest either that ferric citrate complexes with higher molar ratios of iron to citrate relative to the incubation medium are bound preferentially to the membrane, or that once citrate has delivered its iron to the membrane, the complex dissociates and the components are internalised separately. (au)

Antigen Uptake during Different Life Stages of Zebrafish (Danio rerio) Using a GFP-Tagged Yersinia ruckeri

DEFF Research Database (Denmark)

Korbut, Rozalia; Mehrdana, Foojan; Kania, Per Walter

2016-01-01

Immersion-vaccines (bacterins) are routinely used for aquacultured rainbow trout to protect against Yersinia ruckeri (Yr). During immersion vaccination, rainbow trout take up and process the antigens, which induce protection. The zebrafish was used as a model organism to study uptake mechanisms...... the gut was consistently a major uptake site. Zebrafish and rainbow trout tend to have similar uptake mechanisms following immersion or bath vaccination, which points towards zebrafish as a suitable model organism for this aquacultured species....

Diffuse Pulmonary Uptake of Tc-99m Methylene Diphosphonate in a Patient with Non-tuberculosis Mycobacterial Infection

International Nuclear Information System (INIS)

Kwon, Hyun Woo; Chung, June Key; Lee, Dong Soo; Ab-Aziz, Aini

2010-01-01

Extra-osseous uptake of bone-seeking radiopharmaceuticals has been reported at various sites and it is known to be induced by various causes. Diffuse pulmonary infection, such as tuberculosis, can be a cause of lung uptake of bone-scan agent. Here we report on a patient with non-tuberculosis mycobacterial infection (NTM) who demonstrated diffuse pulmonary uptake on Tc-99m MDP bone scan. After medical treatment for NTM, the patient's lung lesions improved. Estra skeletal lung Tc-99m MDP uptake on bone scan may suggest lung parenchymal damage associated with disease activity.

Thyroid uptake test

International Nuclear Information System (INIS)

Ganatra, R.D.

1992-01-01

The uptake of radioiodine by the thyroid gland is altered by the iodine content of diet or drugs. American diet has a high iodine content because each slice of the white bread contains nearly 150μg of iodine due to the bleaching process employed in the production of the bread. This carrier content of iodine reduces the uptake so much, that the normal American uptakes are usually three to four times lower than the uptakes in the developing countries. The other drawback of the thyroid uptake test is that it is affected by the iodine containing drugs. Anti-diarrhoea medications are quire common in the developing countries and many of them contain iodine moiety. Without a reliable drug history, a low thyroid uptake value may lead to a misleading conclusion

Study of immediate technetium 99m uptake by intracranial meningiomas and meningoblastomas

International Nuclear Information System (INIS)

Garcin, Gerard.

1976-01-01

The immediate uptake of technetium 99m in 43 meningiomas and meningoblastomas, observed with a scintillation camera, was analysed. The study concerns the first 30 seconds of the scintigraphic examination, a period corresponding to the arrival of the tracer in the carotids and its progress in the brain circulation (arterial time, capillary time and venous time). The principle of the examination and the facilities of use of the tracer employed are described, after which the examination procedure and the normal images obtained are reported. The technique applied to these 43 patients revealed an instant uptake site in 37 cases, i.e. about 65%. Of the 6 remaining cases 2 were meningiomas of the posterior cranial fossa, 1 was due to technical mistakes, another corresponded to a cystic meningioma of the convexity and the last two to meningiomas of the small splenoid wing. These results confirm those of other authors. Other immediate uptake centres are provided by angiomas, arteriovenous anevrisms and certain glioblastomas. This sign although very important for the meningioma diagnosis, must be corroborated by results of other examinations. It would be useful to make a kinematic study of instant uptake in order to establish, if possible, the exact time of appearance (arterial, capillary or veinous) of this site in meningiomas and in other tumours where the some clinical sign is observed [fr

Ethanol intake and 3H-serotonin uptake II: A study in alcoholic patients using platelets 3H-paroxetine binding

International Nuclear Information System (INIS)

Daoust, M.; Boucly, P.; Ernouf, D.; Breton, P.; Lhuintre, J.P.

1991-01-01

The kinetic parameters of 3 H-paroxetine binding and 3 H-serotonin uptake were studied in platelets of alcoholic patients. There was no difference between alcoholic and non alcoholic subjects in 3 H-paroxetine binding. When binding and 3 H-serotonin uptake were studied, in the same plasma of the same subjects, the Vmax of serotonin uptake was increased in alcoholics. The data confirm the involvement of serotonin uptake system in alcohol dependance and suggest that serotonin uptake and paroxetine binding sites may be regulated independently in this pathology

High FDG uptake areas on pre-radiotherapy PET/CT identify preferential sites of local relapse after chemoradiotherapy for locally advanced oesophageal cancer

Energy Technology Data Exchange (ETDEWEB)

Calais, Jeremie; Lemarignier, Charles; Vera, Pierre [Henri Becquerel Cancer Center and Rouen University Hospital, Nuclear Medicine Department, Rouen (France); University of Rouen, QuantIF-LITIS (Equipe d' Accueil 4108-FR CNRS 3638), Faculty of Medicine, Rouen (France); Dubray, Bernard [University of Rouen, QuantIF-LITIS (Equipe d' Accueil 4108-FR CNRS 3638), Faculty of Medicine, Rouen (France); Centre Henri Becquerel and Rouen University Hospital, Department of Radiotherapy and Medical Physics, Rouen (France); Nkhali, Lamyaa; Thureau, Sebastien; Modzelewski, Romain; Gardin, Isabelle [Henri Becquerel Cancer Center and Rouen University Hospital, Nuclear Medicine Department, Rouen (France); University of Rouen, QuantIF-LITIS (Equipe d' Accueil 4108-FR CNRS 3638), Faculty of Medicine, Rouen (France); Centre Henri Becquerel and Rouen University Hospital, Department of Radiotherapy and Medical Physics, Rouen (France); Di Fiore, Frederic [Rouen University Hospital, Department of Gastroenterology, Rouen (France); Rouen University Hospital, Department of Oncology, Henri Becquerel Cancer Center, IRON, Rouen (France); Michel, Pierre [Rouen University Hospital, Department of Gastroenterology, Rouen (France)

2015-05-01

The high failure rates in the radiotherapy (RT) target volume suggest that patients with locally advanced oesophageal cancer (LAOC) would benefit from increased total RT doses. High 2-deoxy-2-[{sup 18}F]fluoro-D-glucose (FDG) uptake (hotspot) on pre-RT FDG positron emission tomography (PET)/CT has been reported to identify intra-tumour sites at increased risk of relapse after RT in non-small cell lung cancer and in rectal cancer. Our aim was to confirm these observations in patients with LAOC and to determine the optimal maximum standardized uptake value (SUV{sub max}) threshold to delineate smaller RT target volumes that would facilitate RT dose escalation without impaired tolerance. The study included 98 consecutive patients with LAOC treated by chemoradiotherapy (CRT). All patients underwent FDG PET/CT at initial staging and during systematic follow-up in a single institution. FDG PET/CT acquisitions were coregistered on the initial CT scan. Various subvolumes within the initial tumour (30, 40, 50, 60, 70, 80 and 90 % SUV{sub max} thresholds) and in the subsequent local recurrence (LR, 40 and 90 % SUV{sub max} thresholds) were pasted on the initial CT scan and compared[Dice, Jaccard, overlap fraction (OF), common volume/baseline volume, common volume/recurrent volume]. Thirty-five patients had LR. The initial metabolic tumour volume was significantly higher in LR tumours than in the locally controlled tumours (mean 25.4 vs 14.2 cc; p = 0.002). The subvolumes delineated on initial PET/CT with a 30-60 % SUV{sub max} threshold were in good agreement with the recurrent volume at 40 % SUV{sub max} (OF = 0.60-0.80). The subvolumes delineated on initial PET/CT with a 30-60 % SUV{sub max} threshold were in good to excellent agreement with the core volume (90 % SUV{sub max}) of the relapse (common volume/recurrent volume and OF indices 0.61-0.89). High FDG uptake on pretreatment PET/CT identifies tumour subvolumes that are at greater risk of recurrence after CRT in

Uptake of mercury vapor by wheat. An assimilation model

International Nuclear Information System (INIS)

Browne, C.L.; Fang, S.C.

1978-01-01

Using a whole-plant chamber and 203 Hg-labeled mercury, a quantitative study was made of the effect of environmental parameters on the uptake, by wheat (Triticum aestivum), of metallic mercury vapor, an atmospheric pollutant. Factors were examined in relation to their influence on components of the gas-assimilation model, U(Hg) = (C/sub A' -- C/sub L')/(r/sub L.Hg/ + r/sub M.Hg/) where U(Hg) is the rate of mercury uptake per unit leaf surface, C/sub A'/ is the ambient mercury vapor concentration, C/sub L'/ is the mercury concentration at immobilization sites within the plant (assumed to be zero), r/sub L.Hg/ is the total leaf resistance to mercury vapor exchange, and r/sub M.Hg/ is a residual term to account for unexplained physical and biochemical resistances to mercury vapor uptake. Essentially all mercury vapor uptake was confined to the leaves. r/sub L.Hg/ was particularly influenced by illumination (0 to 12.8 klux), but unaffected by ambient temperature (17 to 33 0 C) and mercury vapor concentration (0 to 40 μg m -3 ). The principal limitation to mercury vapor uptake was r/sub M.Hg/, which was linearly related to leaf temperature, but unaffected by mercury vapor concentration and illumination, except for apparent high values in darkness. Knowing C/sub A'/ and estimating r/sub L.Hg/ and r/sub M.Hg/ from experimental data, mercury vapor uptake by wheat in light was accurately predicted for several durations of exposure using the above model

Technetium-99m-HDP uptake characteristics in equine fractures: a retrospective study.

Science.gov (United States)

Scheidegger, E; Geissbühlerl, U; Doherr, M G; Lang, J

2006-10-01

Bone scintigraphy is a very sensitive diagnostic tool to detect elevated bone metabolism. In cases of fractures and fissure fractures, the radiopharmaceutical uptake in the bone is said to be increased within a few hours after the injury. In this retrospective study, the scintigraphic uptake characteristics at the fracture site of 36 horses with radiographically confirmed fractures or fissure fractures were evaluated. Uptake ratios between the fracture region and adjacent normal bone or soft tissue activity respectively were calculated and compared to different anamnestic and radiographic data. The overall sensitivity of bone scintigraphy was 94.4% (34 positive cases out of 36). In the 36 horses, no correlation between the age of the fracture and the radiopharmaceutical uptake was found. However, there seems to be a lack of sensitivity in early detection of equine pelvic fractures when a standing bone scintigraphy examination protocol is used.

Uptake and localisation of lead in the root system of Brassica juncea

International Nuclear Information System (INIS)

Meyers, Donald E.R.; Auchterlonie, Graeme J.; Webb, Richard I.; Wood, Barry

2008-01-01

The uptake and distribution of Pb sequestered by hydroponically grown (14 days growth) Brassica juncea (3 days exposure; Pb activities 3.2, 32 and 217 μM) was investigated. Lead uptake was restricted largely to root tissue. Examination using scanning transmission electron microscopy-energy dispersive spectroscopy revealed substantial and predominantly intracellular uptake at the root tip. Endocytosis of Pb at the plasma membrane was not observed. A membrane transport protein may therefore be involved. In contrast, endocytosis of Pb into a subset of vacuoles was observed, resulting in the formation of dense Pb aggregates. Sparse and predominantly extracellular uptake occurred at some distance from the root tip. X-ray photoelectron spectroscopy confirmed that the Pb concentration was greater in root tips. Heavy metal rhizofiltration using B. juncea might therefore be improved by breeding plants with profusely branching roots. Uptake enhancement using genetic engineering techniques would benefit from investigation of plasma membrane transport mechanisms. - The sites of Pb sequestration within the root system of hydroponically grown Brassica juncea were identified

Clinical Significance of Incidental Focal 18F-FDG Uptake in the Spinal Cord of Patients with Cancer.

Science.gov (United States)

Lim, Chae Hong; Hyun, Seung Hyup; Moon, Seung Hwan; Cho, Young Seok; Choe, Yearn Seong; Lee, Kyung-Han; Kim, Byung-Tae; Choi, Joon Young

2017-09-01

We investigated the incidence, location, and clinical significance of focal 18 F-FDG uptake of the spinal cord in patients with cancer. We reviewed the medical records of 22,937 consecutive adult patients with known or suspicious malignancy who underwent 18 F-FDG PET/CT. PET/CT scans with incidental focal spinal cord uptake were selected and retrospectively reviewed to determine the presence, location, number, and maximum standardized uptake value (SUV max ) of any focal hypermetabolic lesions of the spinal cord. In subjects with focal spinal uptake, clinical characteristics and clinical follow-up results, including follow-up PET/CT, were reviewed. Incidental focal spinal cord uptake was observed in 69 of 22,937 adult patients (incidence = 0.3%; M:F = 31:38; age, 55.8 ± 14.7 years). Seventy-eight focal hypermetabolic lesions on spinal cord in the PET/CT scans of the 69 study subjects were analyzed. The most common sites of focal spinal cord uptake were the T12 vertebra (47/78; 60.3%) and L1 vertebra (20/78; 25.6%). Multifocal cord uptake was found in 8 of 69 patients (11.6%). The average SUV max for cord uptake was 2.5 ± 0.5 (range, 1.4∼3.9). There was no clinical or imaging evidence of abnormalities in the spinal cord, both at the time of PET/CT and during clinical follow-up. Although incidental focal 18 F-FDG uptake of the spinal cord is rare in patients with cancer, it may be physiological or benign, but it should not be considered as malignant involvement. Common sites for the uptake were in the T12 and L1 spine levels.

About methodology to study plant uptake of radionuclides from soil

International Nuclear Information System (INIS)

Tuleubaev, B.A.; Ptitskaya, L.D.

2000-01-01

This paper presents methodology for studying particular features of radionuclides uptake by plants from contaminated soil as applied to the use of the former Semipalatinsk tet site territory, which are dependent upon physical-chemical and physical-mechanical properties of soil and biological peculiarities of meadow-pasture vegetation. (author)

Plant uptake of dual-labeled organic N biased by inorganic C uptake

DEFF Research Database (Denmark)

Rasmussen, Jim; Sauheitl, Leopold; Eriksen, Jørgen

2010-01-01

glycine or CO2-3 , but found no differences in uptake rates between these C-sources. The uptake of inorganic C to the shoot tissue was higher for maize grown in full light compared to shading, which indicates a passive uptake of inorganic C with water. We conclude that uptake of inorganic C produced...

Characterization of taurine binding, uptake, and release in the rat hypothalamus

International Nuclear Information System (INIS)

Hanretta, A.T.

1985-01-01

The neurotransmitter criteria of specific receptors, inactivation, and release were experimentally examined for taurine in the hypothalamus. Specific membrane binding and synaptosomal uptake of taurine both displayed high affinity and low affinity systems. The neurotransmitter criterion of release was studied in superfused synaptosomes. Exposure of synaptosomes which had been preloaded with a concentration of [ 3 H]taurine in the high affinity uptake range (1.5 μM) to either 56 mM K + or 100 μM veratridine evoked a Ca 2+ -independent release. Exposure of synaptosomes which had been preloaded with a concentration of [ 3 H]taurine in the low affinity uptake range (2 mM) to 56 mM K + induced a Ca 2+ -independent release, whereas 100 + M veratridine did not, either in the presence or absence of Ca 2+ . Based on these results, as well as other observations, a model is proposed in which the high affinity uptake system is located on neuronal membranes and the low affinity uptake system is located on glial membranes. The mechanisms of binding, uptake, and release in relation to the cellular location of each are discussed. We conclude that the neurotransmitter criterion of activation by re-uptake is satisfied for taurine in the hypothalamus. However, the failure to demonstrate both a specific taurine receptor site and a Ca 2+ -dependent evoked release, necessitates that we conclude that taurine appears not to function as a hypothalamic neurotransmitter, at least not in the classical sense

Diffuse Pulmonary Uptake of Tc-99m Methylene Diphosphonate in a Patient with Non-tuberculosis Mycobacterial Infection

Energy Technology Data Exchange (ETDEWEB)

Kwon, Hyun Woo; Chung, June Key; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Ab-Aziz, Aini [University Kebangsaan Malaysia Medical Centre, Kuala Lumpur, (Morocco)

2010-06-15

Extra-osseous uptake of bone-seeking radiopharmaceuticals has been reported at various sites and it is known to be induced by various causes. Diffuse pulmonary infection, such as tuberculosis, can be a cause of lung uptake of bone-scan agent. Here we report on a patient with non-tuberculosis mycobacterial infection (NTM) who demonstrated diffuse pulmonary uptake on Tc-99m MDP bone scan. After medical treatment for NTM, the patient's lung lesions improved. Estra skeletal lung Tc-99m MDP uptake on bone scan may suggest lung parenchymal damage associated with disease activity.

Cardiac iodine-123 metaiodobenzylguanidine uptake in animals with diabetes mellitus and/or hypertension

International Nuclear Information System (INIS)

Dubois, E.A.; Kam, K.L.; Somsen, G.A.; Boer, G.J.; Bruin, K. de; Batink, H.D.; Pfaffendorf, M.; Royen, E.A. van; Zwieten, P.A. van

1996-01-01

The aim of the present study was to evaluate the use of the noradrenaline analogue iodine-123 metaiodobenzylguanidine ([ 123 I]MIBG) for the assessment of cardiac sympathetic activity in the presence of diabetes mellitus and/or hypertension in animal models. One model used Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) rendered diabetic at 12 weeks of age by an intravenous injection of streptozotocin (STZ). The other model used lean and obese Zucker rats. In all groups basic haemodynamic values were established and animals received an intravenous injection of 50 μCi [ 123 I]MIBG. Initial myocardial uptake and washout rates of [ 123 I]MIBG were measured scintigraphically during 4 h. After sacrifice, plasma noradrenaline and left cardiac ventricular β-adrenoceptor density was determined. The diabetic state, both in STZ-treated rats (direct induction) and in obese Zucker rats (genetic induction), appeared to induce a lower cardiac density of β-adrenoceptors, indicative of increased sympathetic activity. Cardiac [ 123 I]MIBG then showed increased washouts, thereby confirming enhanced noradrenergic activity. This parallism of results led to the conclusion that [ 123 I]MIBG wash-out measurements could provide an excellent tool to assess cardiac sympathetic activity noninvasively. However, in hypertension (WKY vs SHR), both parameters failed to show parallelism: no changes in β-adrenoceptor density were found, whereas [ 123 I]MIBG wash-out rate was increased. Thus, either [ 123 I]MIBG washout or β-adrenoceptor density may not be a reliable parameter under all circumstances to detect changes in the release of noradrenaline. (orig./MG)

FDG uptake in the fatty tissues of supraclavicular and the vascular structure of the lung hilum

International Nuclear Information System (INIS)

Dang Yaping; Liu Gang; Li Miao

2004-01-01

Full text: Supraclavicular region (SR) and lung hilum (LH) are common sites for lymph node metastases. A commonly reported site of non-malignant FDG uptake on PET imaging in the SR is muscular uptake. PET/CT offers a unique technique to correlate PET findings with CT anatomy in the SR and LH. We carried out this study to investigate FDG uptake in SR and LH to find out the exact tissues of FDG uptake. From September 2002 to March 2003, 147 consecutive patients imaged by FDG PET/CT whole-body scan (GE Discovery LS, CT attenuation correction, OSEM reconstruction) were retrospectively reviewed. The presence of abnormal FDG uptake on PET images in SR and LH regions was evaluated and the corresponding CT findings on the same regions were also assessed. Of the 147 patients, 8 cases (2M, 6F and mean age 44 years) were found with increased symmetrical FDG uptake in the regions of the lower neck and shoulder as well as costo-vertebral articulations. The positive rates were 2.1% and 11.3% for men and women respectively, and the average rate was 5.4%. However, no FDG uptake was seen in the greater muscular structures of the cervical or thoracic spine. FDG uptake was seen in the fatty tissue between the shoulder muscle and the dorsal thoracic wall, but not within the muscles itself. Five patients (3M, 2F, age 56-74 years, 3.4%) showed abnormal FDG uptake in LH, which were definitely localized in the vascular structure of the lung hilum by CT. Co-registered PET/CT imaging shows that the FDG uptake, though well known in the SR and LH regions, is not fully located in greater muscular structures and lymph nodes, but in the costo-vertebral articulation complex of the thoracic spine and fatty tissue of the shoulders as well as in the vascular structure of both lung hilum. The FDG uptake in the fatty tissue of the shoulders was mostly seen in women, while the uptake in vascular structure of the lung hilum were found in aged people. (author)

Reactive Uptake of Sulfur Dioxide and Ozone on Volcanic Glass and Ash at Ambient Temperature

Science.gov (United States)

Maters, Elena C.; Delmelle, Pierre; Rossi, Michel J.; Ayris, Paul M.

2017-09-01

The atmospheric impacts of volcanic ash from explosive eruptions are rarely considered alongside those of volcanogenic gases/aerosols. While airborne particles provide solid surfaces for chemical reactions with trace gases in the atmosphere, the reactivity of airborne ash has seldom been investigated. Here we determine the total uptake capacity (NiM) and initial uptake coefficient (γM) for sulfur dioxide (SO2) and ozone (O3) on a compositional array of volcanic ash and glass powders at 25°C in a Knudsen flow reactor. The measured ranges of NiSO2 and γSO2 (1011-1013 molecules cm-2 and 10-3-10-2) and NiO3 and γO3 (1012-1013 molecules cm-2 and 10-3-10-2) are comparable to values reported for mineral dust. Differences in ash and glass reactivity toward SO2 and O3 may relate to varying abundances of, respectively, basic and reducing sites on these materials. The typically lower SO2 and O3 uptake on ash compared to glass likely results from prior exposure of ash surfaces to acidic and oxidizing conditions within the volcanic eruption plume/cloud. While sequential uptake experiments overall suggest that these gases do not compete for reactive surface sites, SO2 uptake forming adsorbed S(IV) species may enhance the capacity for subsequent O3 uptake via redox reaction forming adsorbed S(VI) species. Our findings imply that ash emissions may represent a hitherto neglected sink for atmospheric SO2 and O3.

Multiple pathways of sigma(1) receptor ligand uptakes into primary cultured neuronal cells.

Science.gov (United States)

Yamamoto, H; Karasawa, J; Sagi, N; Takahashi, S; Horikomi, K; Okuyama, S; Nukada, T; Sora, I; Yamamoto, T

2001-08-03

Although many antipsychotics have affinities for sigma receptors, the transportation pathway of exogenous sigma(1) receptor ligands to intracellular type-1 sigma receptors are not fully understood. In this study, sigma(1) receptor ligand uptakes were studied using primary cultured neuronal cells. [(3)H](+)-pentazocine and [(3)H](R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl)piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate (MS-377), used as a selective sigma(1) receptor ligands, were taken up in a time-, energy- and temperature-dependent manner, suggesting that active transport mechanisms were involved in their uptakes. sigma(1) receptor ligands taken up into primary cultured neuronal cells were not restricted to agonists, but also concerned antagonists. The uptakes of these ligands were mainly Na(+)-independent. Kinetic analysis of [(3)H](+)-pentazocine and [(3)H]MS-377 uptake showed K(m) values (microM) of 0.27 and 0.32, and V(max) values (pmol/mg protein/min) of 17.4 and 9.4, respectively. Although both ligands were incorporated, the pharmacological properties of these two ligands were different. Uptake of [(3)H](+)-pentazocine was inhibited in the range 0.4-7.1 microM by all the sigma(1) receptor ligands used, including N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy)phenyl]ethylamine monohydrochloride (NE-100), a selective sigma(1) receptor ligand. In contrast, the inhibition of [(3)H]MS-377 uptake was potently inhibited by haloperidol, characterized by supersensitivity (IC(50), approximately 2 nM) and was inhibited by NE-100 with low sensitivity (IC(50), 4.5 microM). Moreover, kinetic analysis revealed that NE-100 inhibited [(3)H]MS-377 uptake in a noncompetitive manner, suggesting that NE-100 acted at a site different from the uptake sites of [(3)H]MS-377. These findings suggest that there are at least two uptake pathways for sigma(1) receptor ligands in primary cultured neuronal cells (i.e. a haloperidol-sensitive pathway and another, unclear, pathway). In

Forest Transpiration: Resolving Species-Specific Root Water Uptake Patterns

Science.gov (United States)

Blume, T.; Heidbuechel, I.; Simard, S.; Guntner, A.; Weiler, M.; Stewart, R. D.

2016-12-01

Transpiration and its spatio-temporal variability are still not fully understood, despite their importance for the global water cycle. This is in part due to our inability to measure transpiration comprehensively. Transpiration is usually either estimated with empirical equations based on climatic variables and crop factors, by measuring sap velocities, estimating sap wood area and scaling up to the forest stand based on a number of assumptions or by measuring the integral signal across a footprint with eddy flux towers. All these methods are focused on the cumulated loss of water to the atmosphere and do not provide information on where this water is coming from. In this study, spatio-temporal variability of root water uptake was investigated in a forest in the northeastern German lowlands. The soils are sandy and the depth of the unsaturated zone ranges from 1 to 30 m. We estimated root water uptake from different soil depths, from 0.1 m down to 2 m, based on diurnal fluctuations in soil moisture content during rain-free days. The 15 field sites cover different topographic positions and forest stands: 4 pure stands of both mature and young beech and pine and 9 mixed stands. The resulting daily data set of root water uptake shows that the forest stands differ in total amounts as well as in uptake depth distributions. Temporal dynamics of signal strength within the profile suggest a locally shifting spatial distribution of uptake that changes with water availability. The relationship of these depth-resolved uptake rates to overall soil water availability varies considerably between tree species. Using the physically-based soil hydrological model HYDRUS we investigated to what extent the observed patterns in uptake can be related to soil physical relationships alone and where tree species-specific aspects come into play. We furthermore used the model to test assumptions and estimate uncertainties of this soil moisture based estimation of plant water uptake. The

Clinical significance of incidental focal "1"8F-FDG uptake in the spinal cord of patients with cancer

International Nuclear Information System (INIS)

Lim, Chae Hong; Hyun, Seung Hyup; Moon, Seung Hwan; Cho, Young Seok; Choe, Yearn Seong; Lee, Kyung Han; Kim, Byung Tae; Choi, Joon Young

2017-01-01

We investigated the incidence, location, and clinical significance of focal "1"8F-FDG uptake of the spinal cord in patients with cancer. We reviewed the medical records of 22,937 consecutive adult patients with known or suspicious malignancy who underwent "1"8F-FDG PET/CT. PET/CT scans with incidental focal spinal cord uptake were selected and retrospectively reviewed to determine the presence, location, number, and maximum standardized uptake value (SUV_m_a_x) of any focal hypermetabolic lesions of the spinal cord. In subjects with focal spinal uptake, clinical characteristics and clinical follow-up results, including follow-up PET/CT, were reviewed. Incidental focal spinal cord uptake was observed in 69 of 22,937 adult patients (incidence = 0.3%; M:F = 31:38; age, 55.8 ± 14.7 years). Seventy-eight focal hypermetabolic lesions on spinal cord in the PET/CT scans of the 69 study subjects were analyzed. The most common sites of focal spinal cord uptake were the T12 vertebra (47/78; 60.3%) and L1 vertebra (20/78; 25.6%). Multifocal cord uptake was found in 8 of 69 patients (11.6%). The average SUVmax for cord uptake was 2.5 ± 0.5 (range, 1.4∼3.9). There was no clinical or imaging evidence of abnormalities in the spinal cord, both at the time of PET/CT and during clinical follow-up. Although incidental focal "1"8F-FDG uptake of the spinal cord is rare in patients with cancer, it may be physiological or benign, but it should not be considered as malignant involvement. Common sites for the uptake were in the T12 and L1 spine levels

Clinical significance of incidental focal {sup 18}F-FDG uptake in the spinal cord of patients with cancer

Energy Technology Data Exchange (ETDEWEB)

Lim, Chae Hong; Hyun, Seung Hyup; Moon, Seung Hwan; Cho, Young Seok; Choe, Yearn Seong; Lee, Kyung Han; Kim, Byung Tae; Choi, Joon Young [Dept. of Nuclear Medicine, Samsung Medical CenterSungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2017-09-15

We investigated the incidence, location, and clinical significance of focal {sup 18}F-FDG uptake of the spinal cord in patients with cancer. We reviewed the medical records of 22,937 consecutive adult patients with known or suspicious malignancy who underwent {sup 18}F-FDG PET/CT. PET/CT scans with incidental focal spinal cord uptake were selected and retrospectively reviewed to determine the presence, location, number, and maximum standardized uptake value (SUV{sub max}) of any focal hypermetabolic lesions of the spinal cord. In subjects with focal spinal uptake, clinical characteristics and clinical follow-up results, including follow-up PET/CT, were reviewed. Incidental focal spinal cord uptake was observed in 69 of 22,937 adult patients (incidence = 0.3%; M:F = 31:38; age, 55.8 ± 14.7 years). Seventy-eight focal hypermetabolic lesions on spinal cord in the PET/CT scans of the 69 study subjects were analyzed. The most common sites of focal spinal cord uptake were the T12 vertebra (47/78; 60.3%) and L1 vertebra (20/78; 25.6%). Multifocal cord uptake was found in 8 of 69 patients (11.6%). The average SUVmax for cord uptake was 2.5 ± 0.5 (range, 1.4∼3.9). There was no clinical or imaging evidence of abnormalities in the spinal cord, both at the time of PET/CT and during clinical follow-up. Although incidental focal {sup 18}F-FDG uptake of the spinal cord is rare in patients with cancer, it may be physiological or benign, but it should not be considered as malignant involvement. Common sites for the uptake were in the T12 and L1 spine levels.

An exposure system for measuring nasal and lung uptake of vapors in rats

Energy Technology Data Exchange (ETDEWEB)

Dahl, A.R.; Brookins, L.K.; Gerde, P. [National Inst. for Working Life, Solna (Sweden)

1995-12-01

Inhaled gases and vapors often produce biological damage in the nasal cavity and lower respiratory tract. The specific site within the respirator tract at which a gas or vapor is absorbed strongly influences the tissues at risk to potential toxic effects; to predict or to explain tissue or cell specific toxicity of inhaled gases or vapors, the sites at which they are absorbed must be known. The purpose of the work reported here was to develop a system for determining nose and lung absorption of vapors in rats, an animal commonly used in inhalation toxicity studies. In summary, the exposure system described allows us to measure in the rate: (1) nasal absorption and desorption of vapors; (2) net lung uptake of vapors; and (3) the effects of changed breathing parameters on vapor uptake.

Utilization of a Model for Uptake of Cadmium by Plants as a Phytoremediation Assessment Tool

Science.gov (United States)

Takahashi, M.; Furbish, D. J.; Clarke, J.

2008-12-01

Some traditional methods of environmental remediation, such as removal and disposal of contaminated soil, are loosing economic favor and public acceptance, while others, such as in situ phytoremediation, are being carefully examined because of their attractiveness as environmentally friendly, low-cost solutions to site clean-up. The success of phytoremediation strategies, however, hinges on the ability of selected plants, or plant communities, to effectively uptake, accumulate and tolerate targeted contaminants. Heavy metals, specifically cadmium (Cd), are not essential nutrients to plants. However, chemically similar zinc (Zn) is a micronutrient and is actively taken up by hyperaccumulators. For this reason, the mechanisms involved in uptake of Cd parallel those of Zn. Ideally, Cd would be allocated to the stem, leaf, and/or flower, where it becomes harvestable. Our modeling work simulates the uptake and the storage of Cd in a growing hyperaccumulator. After uptake, Cd is partitioned between adsorption to plant tissue and upward movement to leaves driven by transpiration. Uptake, adsorption and transport are also regulated by phytotoxicity. Simulations suggest that a young plant with small biomass can quickly reach phytotoxicity, which shuts down the normal operation of the plant. Conversely, mature plants on a mildly contaminated site, if harvested before the plants die due to phytotoxicity or natural cause, not only survive but may occasionally thrive. The immediate aim is to estimate the effectiveness and limitations of Cd uptake by hyperaccumulators. The eventual goal of this study is to expand the model in spatial and temporal scales, from individual plants to the community scale, and from one harvest interval to several generations. Understanding the interface between physical and biological processes, specifically the uptake and release of contaminants, provides scientists and engineers tools to assess whether phytoremediation is a reasonable strategy for a

Radiostrontium uptake by plants from different soil types in Kazakhstan

International Nuclear Information System (INIS)

Savinkov, A.; Semioshkina, N.; Howard, B.J.; Voigt, G.

2007-01-01

The transfer of 90 Sr to a range of different plant species grown on a range of different soil types in Kazakhstan, including three from the Semipalatinsk Test Site (STS), has been measured in a lysimeter experiment. 90 Sr uptake by Stipa spp was significantly higher than for other vegetation species. The uptake of 90 Sr from chernozem was significantly lower than that from the other soil types which is consistent with other literature. There was a significant negative relationship between 90 Sr uptake and calcium, humus and CEC concentration in the soil for Agropyrum spp, Artemisia spp but not for Stipa spp or Bromus spp. The transfer to vegetation from soil has been quantified using the aggregated transfer coefficients for each species. Tag values range from 0.6 to 11.9 m 2 kg -1 x 10 -3 over all measurements. The transfer of 90 Sr to plants from the Kazakh soils was low compared to previously reported data and to that given from literature reviews

Isoguvacine binding, uptake, and release: relation to the GABA system

Energy Technology Data Exchange (ETDEWEB)

White, W F; Snodgrass, S R

1983-06-01

Isoguvacine (1,2,3,6-tetrahydropyridine-4-carboxylic acid) is a GABA (gamma-aminobutyric acid) agonist with limited conformational flexibility. In these studies we investigated the binding, uptake, and release of (3H) isoguvacine by use of tissue preparations of rat CNS, comparing the results with similar studies of (3H)GABA. The results from these investigations indicate that isoguvacine binds to membrane preparations of rat forebrain with pharmacological characteristics similar to the post-synaptic GABA recognition site; that it is transported into synaptosomal preparations by an uptake system similar to the high-affinity GABA uptake system; and that recently accumulated isoguvacine is released in a Ca2+-dependent manner and by heteroexchange with external GABA. The ability of isoguvacine and gamma-hydroxybutyric acid to decrease the K+-stimulated Ca2+-dependent release process was also investigated. The results indicate that isoguvacine interactions have many of the biochemical features of GABA synaptic function, isoguvacine being, however, less potent than GABA.

Determination of maximum physiologic thyroid uptake and correlation with 24-hour RAI uptake value

International Nuclear Information System (INIS)

Duldulao, M.; Obaldo, J.

2007-01-01

Full text: In hyperthyroid patients, thyroid uptake values are overestimated, sometimes approaching or exceeding 100%. This is physiologically and mathematically impossible. This study was undertaken to determine the maximum physiologic thyroid uptake value through a proposed simple method using a gamma camera. Methodology: Twenty-two patients (17 females and 5 males), with ages ranging from 19-61 y/o (mean age ± SD; 41 ± 12), with 24-hour uptake value of >50%, clinically hyperthyroid and referred for subsequent radioactive iodine therapy were studied. The computed maximum physiologic thyroid uptake was compared with the 24-hour uptake using the paired Student t-test and evaluated using linear regression analysis. Results: The computed physiologic uptake correlated poorly with the 24-hour uptake value. However, in the male subgroup, there was no statistically significant difference between the two (p=0.77). Linear regression analysis gives the following relationship: physiologic uptake (%) = 77.76 - 0.284 (24-hour RAI uptake value). Conclusion: Provided that proper regions of interest are applied with correct attenuation and background subtraction, determination of physiologic thyroid uptake may be obtained using the proposed method. This simple method may be useful prior to I-131 therapy for hyperthyroidism especially when a single uptake determination is performed. (author)

Nutrient Uptake and Metabolism Along a Large Scale Tropical Physical-Chemical Gradient

Science.gov (United States)

Tromboni, F.; Neres-Lima, V.; Saltarelli, W. A.; Miwa, A. C. P.; Cunha, D. G. F.

2016-12-01

Nutrient spiraling is a whole-system approach for estimating nutrient uptake that can be used to assess aquatic ecosystems' responses to environmental change and anthropogenic impacts. Historically research on nutrient dynamic uptake in streams has focused on single nutrient dynamics and only rarely the stoichiometric uptake has been considered and linked to carbon metabolism driven by autotrophic and heterotrophic production. We investigated the relationship between uptake of phosphate (PO43-), nitrate (NO3-) ammonium (NH4+) and total dissolve nitrogen (DIN)/ PO43-; and gross primary production (GPP), respiration (R), and net ecosystem productivity (NEP) in six relatively pristine streams with differences regarding canopy cover and physical characteristics, located in a large scale gradient from tropical Atlantic Forest to an Atlantic forest/Cerrado (Brazilian Savanna) transition. We carried out whole stream instantaneous additions of PO43-, NO3- and NH4+ added to each stream in combination, using the TASCC (Tracer Additions for Spiraling Curve Characterization) method. Metabolism measurements were performed in the same streams right after uptake was measured, using one-station open channel method and re-aeration estimations for those sites. We found different background concentrations in the streams located in the Atlantic forest compared with the transition area with Cerrado. In general PO43- and NO3- uptake increased with the decreasing of canopy cover, while a positive relation with background concentration better explained NH4+uptake. DIN/PO43- uptake increased with increasing R and NEP. Little work on functional characteristics of pristine streams has been conducted in this region and this work provides an initial characterization on nitrogen and phosphorus dynamics as well as their stoichiometric uptake in streams.

Actinide uptake by transferrin and ferritin metalloproteins

International Nuclear Information System (INIS)

Den Auwer, C.; Llorens, I.; Moisy, Ph.; Vidaud, C.; Goudard, F.; Barbot, C.; Solari, P.L.; Funke, H.

2005-01-01

In order to better understand the mechanisms of actinide uptake by specific biomolecules, it is essential to explore the intramolecular interactions between the cation and the protein binding site. Although this has long been done for widely investigated transition metals, very few studies have been devoted to complexation mechanisms of actinides by active chelation sites of metalloproteins. In this field, X-ray absorption spectroscopy has been extensively used as a structural and electronic metal cation probe. The two examples that are presented here are related to two metalloproteins in charge of iron transport and storage in eukaryote cells: transferrin and ferritin. U(VI)O 2 2+ , Np(IV) and Pu(IV) have been selected because of their possible role as contaminant from the geosphere. (orig.)

False-positive 111In-pentetreotide Uptake in Gastritis

International Nuclear Information System (INIS)

Usmani, Sharjeel; Alshammari, Alshaima

2013-01-01

111 In-pentetreotide [ 111 In-octreoscan] is the most widely used radiolabeled somatostatin analog for evaluating neuroendocrine tumor overexpression of somatostatin receptors. False-positives studies of somatostatin receptor scintigraphy have been reported and often the cause is unexplained but assumed to be due to high number of somatostatin receptors in other pathologies. Causes of false-positives include visualization of the gallbladder, nasal mucosa and pulmonary hilar areas in respiratory infections, thyroid abnormalities, accessory spleens, recent Cerebrovascular accidents (CVA's) and activity at the site of a recent surgical incision. In infection or inflammation the cause of false-positive uptake is probably the result of tracer binding by somatostatin receptors on the inflammatory leukocytes. In this case report, we report, a 44-year-old male patient with false-positive 111 In-pentetreotide uptake due to gastritis

Positron imaging feasibility studies: characteristics of 2-deoxyglucose uptake in rodent and canine neoplasms

International Nuclear Information System (INIS)

Larson, S.M.; Weiden, P.L.; Grunbaum, J.

1981-01-01

Uptake of [ 3 H]2-deoxyglucose was studied in BALB/c mice with EMT-6 sarcoma, in Buffalo rats with Morris 7777 hepatoma, and in eight dogs with spontaneous neoplasms: five osteosarcomas and three diffuse lymphomas. High tumor-to-tissue ratios were observed for all tumor types studies. In rodents, peak levels of uptake occurred between 30 min and 1 hr, with a slow loss from the tumor of about 10% per hour thereafter. In dogs there was considerable variability in uptake, both between individuals and at different tumor sites within an individual. Necrotic tumor did not take up the radiotracer. Absolute uptakes, when normalized for body weight, were similar for spontaneous and transplanted neoplasms. These studies provide additional support for the concept that positron emission tomography can be used to obtain functional images of important metabolic processes of tumors, including glycolysis

Nitrogen deposition and prey nitrogen uptake control the nutrition of the carnivorous plant Drosera rotundifolia

Energy Technology Data Exchange (ETDEWEB)

Millett, J., E-mail: j.millett@lboro.ac.uk [Centre for Hydrological and Ecosystem Science, Department of Geography, Loughborough University, Loughborough LE11 3TU (United Kingdom); Foot, G.W. [Centre for Hydrological and Ecosystem Science, Department of Geography, Loughborough University, Loughborough LE11 3TU (United Kingdom); Svensson, B.M. [Department of Plant Ecology and Evolution, Uppsala University, Norbyvägen 18 D, SE-752 36 Uppsala (Sweden)

2015-04-15

Nitrogen (N) deposition has important negative impacts on natural and semi-natural ecosystems, impacting on biotic interactions across trophic levels. Low-nutrient systems are particularly sensitive to changes in N inputs and are therefore more vulnerable to N deposition. Carnivorous plants are often part of these ecosystems partly because of the additional nutrients obtained from prey. We studied the impact of N deposition on the nutrition of the carnivorous plant Drosera rotundifolia growing on 16 ombrotrophic bogs across Europe. We measured tissue N, phosphorus (P) and potassium (K) concentrations and prey and root N uptake using a natural abundance stable isotope approach. Our aim was to test the impact of N deposition on D. rotundifolia prey and root N uptake, and nutrient stoichiometry. D. rotundifolia root N uptake was strongly affected by N deposition, possibly resulting in reduced N limitation. The contribution of prey N to the N contained in D. rotundifolia ranged from 20 to 60%. N deposition reduced the maximum amount of N derived from prey, but this varied below this maximum. D. rotundifolia tissue N concentrations were a product of both root N availability and prey N uptake. Increased prey N uptake was correlated with increased tissue P concentrations indicating uptake of P from prey. N deposition therefore reduced the strength of a carnivorous plant–prey interaction, resulting in a reduction in nutrient transfer between trophic levels. We suggest that N deposition has a negative impact on D. rotundifolia and that responses to N deposition might be strongly site specific. - Highlights: • We measured nutrition of the carnivorous plant Drosera rotundifolia across Europe. • We measured tissue nutrient concentrations and prey and root N uptake at 16 sites. • Tissue N concentrations were a product of root N availability and prey N uptake. • N deposition reduced the maximum amount of N derived from prey. • N deposition reduced the strength of a

Nitrogen deposition and prey nitrogen uptake control the nutrition of the carnivorous plant Drosera rotundifolia

International Nuclear Information System (INIS)

Millett, J.; Foot, G.W.; Svensson, B.M.

2015-01-01

Nitrogen (N) deposition has important negative impacts on natural and semi-natural ecosystems, impacting on biotic interactions across trophic levels. Low-nutrient systems are particularly sensitive to changes in N inputs and are therefore more vulnerable to N deposition. Carnivorous plants are often part of these ecosystems partly because of the additional nutrients obtained from prey. We studied the impact of N deposition on the nutrition of the carnivorous plant Drosera rotundifolia growing on 16 ombrotrophic bogs across Europe. We measured tissue N, phosphorus (P) and potassium (K) concentrations and prey and root N uptake using a natural abundance stable isotope approach. Our aim was to test the impact of N deposition on D. rotundifolia prey and root N uptake, and nutrient stoichiometry. D. rotundifolia root N uptake was strongly affected by N deposition, possibly resulting in reduced N limitation. The contribution of prey N to the N contained in D. rotundifolia ranged from 20 to 60%. N deposition reduced the maximum amount of N derived from prey, but this varied below this maximum. D. rotundifolia tissue N concentrations were a product of both root N availability and prey N uptake. Increased prey N uptake was correlated with increased tissue P concentrations indicating uptake of P from prey. N deposition therefore reduced the strength of a carnivorous plant–prey interaction, resulting in a reduction in nutrient transfer between trophic levels. We suggest that N deposition has a negative impact on D. rotundifolia and that responses to N deposition might be strongly site specific. - Highlights: • We measured nutrition of the carnivorous plant Drosera rotundifolia across Europe. • We measured tissue nutrient concentrations and prey and root N uptake at 16 sites. • Tissue N concentrations were a product of root N availability and prey N uptake. • N deposition reduced the maximum amount of N derived from prey. • N deposition reduced the strength of a

Baseline characteristics of study sites and women enrolled in a three-arm cluster randomized controlled trial: PMTCT uptake and retention (pure) Malawi.

Science.gov (United States)

van Lettow, Monique; Tweya, Hannock; Rosenberg, Nora E; Trapence, Clement; Kayoyo, Virginia; Kasende, Florence; Kaunda, Blessings; Hosseinipour, Mina C; Eliya, Michael; Cataldo, Fabian; Gugsa, Salem; Phiri, Sam

2017-07-11

Malawi introduced an ambitious public health program known as "Option B+" which provides all HIV-infected pregnant and breastfeeding women with lifelong combination antiretroviral therapy, regardless of WHO clinical stage or CD4 cell count. The PMTCT Uptake and REtention (PURE) study aimed at evaluating the effect of peer-support on care-seeking and retention in care. PURE Malawi was a three-arm cluster randomized controlled trial that compared facility-based and community-based models of peer support to standard of care under Option B+ strategy. Each arm was expected to enroll a minimum of 360 women with a total minimum sample size of 1080 participants. 21 sites (clusters) were selected for inclusion in the study. This paper describes the site selection, recruitment, enrollment process and baseline characteristics of study sites and women enrolled in the trial. Study implementation was managed by 3 partner organizations; each responsible for 7 study sites. The trial was conducted in the South East, South West, and Central West zones of Malawi, the zones where the implementing partners operate. Study sites included 2 district hospitals, 2 mission hospitals, 2 rural hospitals, 13 health centers and 1 private clinic. Enrollment occurred from November 2013 to November 2014, over a median period of 31 weeks (range 17-51) by site. A total of 1269 HIV-infected pregnant (1094) and breastfeeding (175) women, who were eligible to initiate ART under Option B+, were enrolled. Each site reached or surpassed the minimum sample size. Comparing the number of women enrolled versus antenatal cohort reports, sites recruited a median of 90% (IQR 75-100) of eligible reported women. In the majority of sites the ratio of pregnant and lactating women enrolled in the study was similar to the ratio of reported pregnant and lactating women starting ART in the same sites. The median age of all women was 27 (IQR 22-31) years. All women have ≥20 months of possible follow-up time; 96%�

Modelling the extra and intracellular uptake and discharge of heavy metals in Fontinalis antipyretica transplanted along a heavy metal and pH contamination gradient

International Nuclear Information System (INIS)

Fernandez, J.A.; Vazquez, M.D.; Lopez, J.; Carballeira, A.

2006-01-01

Samples of the aquatic bryophyte Fontinalis antipyretica Hedw. were transplanted to different sites with the aim of characterizing the kinetics of the uptake and discharge of heavy metals in the extra and intracellular compartments. The accumulation of metals in extracellular compartments, characterized by an initial rapid accumulation, then a gradual slowing down over time, fitted perfectly to a Michaelis-Menten model. The discharge of metals from the same compartment followed an inverse linear model or an inverse Michaelis-Menten model, depending on the metal. In intracellular sites both uptake and discharge occurred more slowly and progressively, following a linear model. We also observed that the acidity of the environment greatly affected metal accumulation in extracellular sites, even when the metals were present at relatively high concentrations, whereas the uptake of metals within cells was much less affected by pH. - The kinetics of uptake and discharge of heavy metals, in different cellular locations, were studied in transplanted aquatic mosses

Effects of lesions to the dorsal noradrenergic bundle on counterconditioning of punished barpressing.

Science.gov (United States)

Tsaltas, E; Gray, J A; Preston, G C

1987-01-01

The possible contribution of the dorsal noradrenergic bundle (DB) to the development of a simple form of counterconditioning (an associative mechanism leading to behavioural tolerance for stress) was assessed by comparison of the performance of animals with 6-hydroxydopamine-induced lesions of the DB to that of sham-operated (SH) animals. Animals engaging in barpressing for food reward on a random-interval (RI) 64 sec schedule were presented with a stimulus signalling the concurrent operation of an RI-64 sec schedule of response-contingent shock. In the control condition (punishment), shock and reward never occurred as a result of the same barpress. In the experimental condition (counterconditioning), the frequency of shock and reward were the same as for the punishment condition but the two events always occurred in succession, with food following shock, as a consequence of the same barpress. DB lesions had no effect on the acquisition of rewarded barpressing or on the initial acquisition of the discrimination between the shock-free and shock-containing (signalled) components of the schedule. However, once performance on the discrimination had reached asymptote, DB animals in the punishment control group showed significantly less suppression to the signal than SH animals. The counterconditioning schedule used was effective, leading to significantly reduced response suppression in the SH animals in comparison to the SH group subjected to punishment. The pattern of findings in the DB groups was consistent with a blockade by the lesion of the development of counterconditioning. These results suggest, therefore, that the DB is involved in at least one associative mechanism leading to tolerance for stress.

Intracerebroventricular administration of okadaic acid induces hippocampal glucose uptake dysfunction and tau phosphorylation.

Science.gov (United States)

Broetto, Núbia; Hansen, Fernanda; Brolese, Giovana; Batassini, Cristiane; Lirio, Franciane; Galland, Fabiana; Dos Santos, João Paulo Almeida; Dutra, Márcio Ferreira; Gonçalves, Carlos-Alberto

2016-06-01

Intraneuronal aggregates of neurofibrillary tangles (NFTs), together with beta-amyloid plaques and astrogliosis, are histological markers of Alzheimer's disease (AD). The underlying mechanism of sporadic AD remains poorly understood, but abnormal hyperphosphorylation of tau protein is suggested to have a role in NFTs genesis, which leads to neuronal dysfunction and death. Okadaic acid (OKA), a strong inhibitor of protein phosphatase 2A, has been used to induce dementia similar to AD in rats. We herein investigated the effect of intracerebroventricular (ICV) infusion of OKA (100 and 200ng) on hippocampal tau phosphorylation at Ser396, which is considered an important fibrillogenic tau protein site, and on glucose uptake, which is reduced early in AD. ICV infusion of OKA (at 200ng) induced a spatial cognitive deficit, hippocampal astrogliosis (based on GFAP increment) and increase in tau phosphorylation at site 396 in this model. Moreover, we observed a decreased glucose uptake in the hippocampal slices of OKA-treated rats. In vitro exposure of hippocampal slices to OKA altered tau phosphorylation at site 396, without any associated change in glucose uptake activity. Taken together, these findings further our understanding of OKA neurotoxicity, in vivo and vitro, particularly with regard to the role of tau phosphorylation, and reinforce the importance of the OKA dementia model for studying the neurochemical alterations that may occur in AD, such as NFTs and glucose hypometabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison between FDG Uptake and Pathologic or Immunohistochemical Parametersin Pre-operative PET/CT Scan of Patient with Primary Colorectal Cancer

International Nuclear Information System (INIS)

Na, Sae Jung; Chung, Yong An; Maeng, Lee So; Kim, Ki Jun; Sohn, Kyung Myung; Kim, Sung Hoon; Sohn, Hyung Sun; Chung, Soo Kyo

2009-01-01

To evaluate the relationship between F-18 FDG uptake of tumor in PET/CT scan and pathological or immunohistochemial parameters of colorectal cancer. 147 colorectal cancer patients who underwent both pre-operative F-18 FDG PET/CT scan and surgery were included. In cases with perceptible FDG uptake in primary tumor, the maximum standardized uptake value (SUVmax) was calculated. The pathologic results such as site, size, depth of invasion (T stage), growth pattern, differentiation of primary tumor, lymph node metastasis and Dukes-Astler and Coller stage and immunohistochemical markers such as expression of EGFR, MLH1, MSH2 and Ki-67 index were reviewed. 146 out of 147 PET/CT scans with colorectal cancer showed perceptible focal FDG uptake. SUVmax showed mild positive linear correlation with size of primary tumor (r=0.277, p=0.001) and Ki-67 index (r=0.226, p=0.019). No significant difference in F-18 FDG uptake was found according to site, depth of invasion (T stage), growth pattern, differentiation of primary tumor, presence of lymph node metastasis, Dukes-Astler and Coller stage and expression of EGFR. The degree of F-18 FDG uptake in colorectal cancer was associated with the size and the degree of Ki-67 index of primary tumor. It could be thought that FDG uptake of primary tumor has a correlation with macroscopic and microscopic tumor growth

Kinetics of adsorption and uptake of Cu2+ by Chlorella vulgaris: influence of pH, temperature, culture age, and cations.

Science.gov (United States)

Mehta, S K; Singh, Alpana; Gaur, J P

2002-03-01

Adsorption and uptake of Cu2+ by Chlorella vulgaris were distinguished by extracting the surface-bound Cu2+ with EDTA. The uptake of Cu2+ followed Michaelis Menten kinetics. The maximum rate of Cu2+ uptake (0.362fmolcell(-1) h(-1)) was obtained at pH 6.0. The rate of Cu2+ uptake was greater for cultures in the exponential phase of growth, and increased with a rise in temperature from 6 to 25 degrees C, thus pointing towards an active mechanism. The maximum number of Cu2+ binding sites was 3.245 fmol cell(-1) at pH 4.5. Adsorption of Cu2+ was strongly pH-dependent thereby indicating that the number and nature of metal binding sites on the cell surface change with changing chemistry of the solution. Unlike uptake, the adsorption remained unaffected by small changes in temperature. Older cultures displayed a higher Cu2+ adsorption capacity than the exponentially growing ones thus suggesting generation of new and/or additional Cu2+ binding sites on older cells of C. vulgaris. By pH titration, the cation-exchange capacity of Chlorella, measured in terms of H+/ Na+ exchange, was about 17 fmol cell(-1) at pH 10.5. Negligible cation exchange capacity at and below pH 5.0 indicated that ion exchange was not the sole mechanism of Cu2+ adsorption by Chlorella. The uptake and adsorption of Cu2+ were inhibited by 100 microM of various cations including other heavy metal ions. The general concept that cations competitively inhibit accumulation of metals in living organisms does not hold for C. vulgaris. Non-competitive, uncompetitive and mixed inhibition of Cu2+ uptake and adsorption by various cations were more common than competitive inhibition.

Iron metabolism in BeWo chorion carcinoma cells. Transferrin-mediated uptake and release of iron

NARCIS (Netherlands)

van der Ende, A.; du Maine, A.; Simmons, C. F.; Schwartz, A. L.; Strous, G. J.

1987-01-01

Growing human choriocarcinoma BeWo b24 cells contain 1.5 X 10(6) functional cell surface transferrin binding sites and 2.0 X 10(6) intracellular binding sites. These cells rapidly accumulate iron at a rate of 360,000 iron atoms/min/cell. During iron uptake the transferrin and its receptor recycle at

Presynaptic beta-adrenoceptors in guinea pig papillary muscle: evidence for adrenaline-mediated positive feedback on noradrenergic transmission

International Nuclear Information System (INIS)

Valenta, B.; Singer, E.A.

1991-01-01

Guinea pig papillary muscles were preincubated in the presence of 5 x 10 - 9 mol/L unlabeled noradrenaline or adrenaline then incubated with ( 3 H)-noradrenaline and superfused. Electrical field stimulation with 180 pulses delivered at 1 or 3 Hz was used to induce overflow of radioactivity. Comparison of the effects of preexposure of the tissue to adrenaline or noradrenaline revealed that adrenaline incubation caused an enhancement of stimulation-evoked overflow of ( 3 H)noradrenaline and a reduction of the effect of exogenously added isoprenaline. Furthermore, the selective beta 2-adrenoceptor antagonist ICI 118,551 (10 - 7 mol/L), but not the selective beta 1-adrenoceptor antagonist ICI 89,406 (10 - 7 mol/L), reduced electrically evoked overflow of ( 3 H)noradrenaline in tissue preincubated with adrenaline but not in tissue preincubated with noradrenaline. The overflow-reducing effect of ICI 118.551 occurred at stimulation with 3 Hz but not at stimulation with 1 Hz. The present results support the hypothesis that noradrenergic transmission in guinea pig papillary muscle is facilitated via beta 2-adrenoceptors, and that adrenaline may serve as transmitter in this positive feedback mechanism after its incorporation into sympathetic nerves

Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River Site

International Nuclear Information System (INIS)

Cummins, C.L.

1994-09-01

As a result of operations at the Savannah River Site (SRS), over 50 radionuclides have been released to the atmosphere and to onsite streams and seepage basins. Now, many of these radionuclides are available to aquatic and/or terrestrial organisms for uptake and cycling through the food chain. Knowledge about the uptake and cycling of these radionuclides is now crucial in evaluating waste management and clean-up alternatives for the site. Numerous studies have been conducted at the SRS over the past forty years to study the uptake and distribution of radionuclides in the Savannah River Site environment. In many instances, bioconcentration factors have been calculated to quantify the uptake of a radionuclide by an organism from the surrounding medium (i.e., soil or water). In the past, it has been common practice to use bioconcentration factors from the literature because site-specific data were not readily available. However, because of the variability of bioconcentration factors due to experimental or environmental conditions, site-specific data should be used when available. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at the Savannah River Site (SRS). An extensive literature search yielded site-specific bioconcentration factors for cesium, strontium, cobalt, plutonium, americium, curium, and tritium. These eight radionuclides have been the primary radionuclides studied at SRS because of their long half lives or because they are major contributors to radiological dose from exposure. For most radionuclides, it was determined that the site-specific bioconcentration factors were higher than those reported in literature. This report also summarizes some conditions that affect radionuclide bioavailability to and bioconcentration by aquatic and terrestrial organisms

Different histopathological subtypes of Hodgkin lymphoma show significantly different levels of FDG uptake

DEFF Research Database (Denmark)

Hutchings, Martin; Loft, Annika; Hansen, Mads

2006-01-01

) patients, 20.8 g/ml in 11 mixed cellularity (MC) patients, and 19.5 g/ml in four patients with unclassified classical HL (CHL-NOS), (ANOVA, p = 0.011). Out of 780 sites (600 lymph node regions plus 180 organs), 208 sites were found to be affected with HL. Mean SUV(max) was 8.3 g/ml in the 12 sites with NLP......, 11.2 g/ml in the 147 sites affected with NS, 14.6 g/ml in the 36 sites with MC, and 13.1 g/ml in the 13 sites with CHL-NOS (ANOVA, p = 0.002). There is a significant difference in FDG/glucose uptake between the different histopathological subtypes of HL....

New Synthesis of nZVI/C Composites as an Efficient Adsorbent for the Uptake of U(VI) from Aqueous Solutions.

Science.gov (United States)

Liu, Haibo; Li, Mengxue; Chen, Tianhu; Chen, Changlun; Alharbi, Njud S; Hayat, Tasawar; Chen, Dong; Zhang, Qiang; Sun, Yubing

2017-08-15

New nanoscale zerovalent iron/carbon (nZVI/C) composites were successfully prepared via heating natural hematite and pine sawdust at 800 °C under nitrogen conditions. Characterization by SEM, XRD, FTIR, and XPS analyses indicated that the as-prepared nZVI/C composites contained a large number of reactive sites. The lack of influence of the ionic strength revealed inner-sphere complexation dominated U(VI) uptake by the nZVI/C composites. Simultaneous adsorption and reduction were involved in the uptake process of U(VI) according to the results of XPS and XANES analyses. The presence of U-C/U-U shells demonstrated that innersphere complexation and surface coprecipitation dominated the U(VI) uptake at low and high pH conditions, respectively. The uptake behaviors of U(VI) by the nZVI/C composites were fitted well by surface complexation modeling with two weak and two strong sites. The maximum uptake capacity of U(VI) by the nZVI/C composites was 186.92 mg/g at pH 4.0 and 328 K. Additionally, the nZVI/C composites presented good recyclability and recoverability for U(VI) uptake in regeneration experiments. These observations indicated that the nZVI/C composites can be considered as potential adsorbents to remove radionuclides for environmental remediation.

Spectroscopic and Microscopic Characterization of Contaminant Uptake and Retention by Carbonates in the Soil and Vadose Zone

International Nuclear Information System (INIS)

Reeder, Richard J.; Fisher, Nicholas S.; Hess, Wayne P.; Beck, Kenneth M.

2003-01-01

The research focus of this previous EMSP grant was assessment of the role that carbonate minerals play in the uptake and sequestration of metal and radionuclide contaminants in soils and the vadose zone for conditions relevant to the Hanford Site and other sites in the DOE Complex. The project was a collaboration among researchers at SUNY-Stony Brook and EMSL/PNNL. Carbonates, particularly calcite, are present in the Hanford subsurface as grain coatings, disseminated particles, and dense caliche layers. Calcite is also predicted to be forming beneath leaking tanks. A range of metal and radionuclide species that pose risks at Hanford and other DOE sites were considered, including U(VI), Cr(CV), Cs, Pb(II), and selected lanthanides (as models for trivalent actinides). Batch sorption and co-precipitation experiments of these metals with pre-equilibrated calcite and selected uptake experiments on natural caliche formed the basis to determine the mechanisms of metal/radionuclide binding and to assess the effect on the stability of the sorbed species and the potential for remobilization. Our results provide ne information that can benefit DOE clean-up methodology and potentially provide new approaches for uptake of selected heavy metals

Benthic O-2 uptake of two cold-water coral communities estimated with the non-invasive eddy correlation technique

DEFF Research Database (Denmark)

Rovelli, Lorenzo; Attard, Karl M.; Bryant, Lee D.

2015-01-01

, was a channel-like sound in Northern Norway at a depth of 220 m. Both sites were characterized by the presence of live mounds of the reef framework-forming scleractinian Lophelia pertusa and reef-associated fauna such as sponges, crustaceans and other corals. The measured O-2 uptake at the 2 sites varied...... times higher than the global mean for soft sediment communities at comparable depths. The measurements document the importance of CWC communities for local and regional carbon cycling and demonstrate that the EC technique is a valuable tool for assessing rates of benthic O2 uptake in such complex...

Implications of abnormal right ventricular thallium uptake in acute myocardial infarction

International Nuclear Information System (INIS)

Nestico, P.F.; Hakki, A.H.; Felsher, J.; Heo, J.; Iskandrian, A.S.

1986-01-01

The correlates of abnormal right ventricular (RV) thallium uptake were examined in 116 patients with documented acute myocardial infarction (AMI) who underwent predischarge thallium-201 scintigraphy at rest, radionuclide angiography and 24-hour ambulatory electrocardiography. The patients were separated into 2 groups: patients group 1 (n = 31) had increased RV thallium uptake and those in group 2 (n = 85) had no such uptake. The 2 groups were comparable in age, type and site of AMI, peak creatine kinase level, systolic blood pressure and heart rate. However, compared with group 2, group 1 had a lower mean left ventricular (LV) ejection fraction (33 +/- 15% vs 39 +/- 14%, p less than 0.05), higher prevalence of increased lung thallium uptake (45% vs 22%, p less than 0.02), more extensive LV perfusion defects (4.4 +/- 2.9 vs 3.0 +/- 3.0 segments, p less than 0.03) and more complex ventricular arrhythmias (55% vs 35%, p less than 0.05). At a mean follow-up of 6 months, 17 patients (8 in group 1 and 9 in group 2) died from cardiac causes. Actuarial life-table analysis showed that the survival rate was better in group 2 than in group 1 (Mantel-Cox statistics = 4.62, p = 0.03). Thus, patients with AMI and abnormal RV thallium uptake have worse LV function, more complex ventricular arrhythmias and worse prognosis

The 'glial' glutamate transporter, EAAT2 (Glt-1) accounts for high affinity glutamate uptake into adult rodent nerve endings.

Science.gov (United States)

Suchak, Sachin K; Baloyianni, Nicoletta V; Perkinton, Michael S; Williams, Robert J; Meldrum, Brian S; Rattray, Marcus

2003-02-01

The excitatory amino acid transporters (EAAT) removes neurotransmitters glutamate and aspartate from the synaptic cleft. Most CNS glutamate uptake is mediated by EAAT2 into glia, though nerve terminals show evidence for uptake, through an unknown transporter. Reverse-transcriptase PCR identified the expression of EAAT1, EAAT2, EAAT3 and EAAT4 mRNAs in primary cultures of mouse cortical or striatal neurones. We have used synaptosomes and glial plasmalemmal vesicles (GPV) from adult mouse and rat CNS to identify the nerve terminal transporter. Western blotting showed detectable levels of the transporters EAAT1 (GLAST) and EAAT2 (Glt-1) in both synaptosomes and GPVs. Uptake of [3H]D-aspartate or [3H]L-glutamate into these preparations revealed sodium-dependent uptake in GPV and synaptosomes which was inhibited by a range of EAAT blockers: dihydrokainate, serine-o-sulfate, l-trans-2,4-pyrrolidine dicarboxylate (PDC) (+/-)-threo-3-methylglutamate and (2S,4R )-4-methylglutamate. The IC50 values found for these compounds suggested functional expression of the 'glial, transporter, EAAT2 in nerve terminals. Additionally blockade of the majority EAAT2 uptake sites with 100 micro m dihydrokainate, failed to unmask any functional non-EAAT2 uptake sites. The data presented in this study indicate that EAAT2 is the predominant nerve terminal glutamate transporter in the adult rodent CNS.

Radiotracers for per studies of neurotransmitter binding sites: Design considerations

International Nuclear Information System (INIS)

Kilbourn, M.R.

1991-01-01

Neurotransmitter binding sites, such as receptors, neuronal uptake systems, and vesicular uptake systems, are important targets for new radiopharmaceutical design. Selection of potential radioligands can be guided by in vitro laboratory data including such characteristics as selectivity and affinity for specific binding sites. However, development of PET radiotracers for use in vivo must include considerations of in vivo pharmacokinetics and metabolism. Introduction of potential radioligands is further narrowed by the demands of the radiochemical synthesis, which must produce radioligands of high chemical and radiochemical purity and of high specific activity. This paper will review examples of previous and current attempts by radiopharmaceutical chemists to meet these demands for new positron emitter-labeled radioligands for PET studies of a wide array of neurotransmitter binding sites

Uptake and utilization of nutrients by developing kernels of Zea mays L

International Nuclear Information System (INIS)

Lyznik, L.A.

1987-01-01

The mechanisms involved in amino acid and sugar uptake by developing maize kernels were investigated. In the pedicel region of maize kernel, the site of nutrient unloading from phloem terminals, amino acids are accumulated in considerable amounts and undergo significant interconversion. A wide spectrum of enzymatic activities involved in the metabolism of amino acids is observed in these tissues. Subsequently, amino acids are taken up by the endosperm tissue in processes which require energy and the presence of carrier proteins. Conversely, no evidence was found that energy and carriers are involved in sugar uptake. This process of sugar uptake is not inhibited by metabolic inhibitors and shows nonsaturable kinetics, but the uptake is pH-dependent. L-glucose is taken up at a significantly reduced rate in comparison to D-glucose uptake. Based on analysis of radioactivity distribution among sugar fractions after incubations of kernels with radiolabeled D-glucose, it seems that sucrose is not efficiently resynthesized from D-glucose in the endosperm tissue. Thus, the proposed mechanism of sucrose transport involving sucrose hydrolysis in the pedicel region and subsequent resynthesis in endosperm cells may not be the main pathway. The evidence that transfer cells play an active role in D-glucose transport is presented

Diffuse Myocardial Uptake of 99mTc-HDP in Multiple Myeloma

International Nuclear Information System (INIS)

Demirel, Koray; Sadic, Murat; Korkmaz, Meliha; Comak, Aylin; Atilgan, Hasan Ikbal; Koca, Goekhan

2013-01-01

Soft tissue uptake is a rare finding in bone scintigraphy, with an incidence of 2%. Although the mechanism has not yet been fully clarified, several causes have been reported for this unusual uptake pattern. This paper presents a case of diffuse myocardial accumulation of technetium-99m hydroxymethylene diphosphonate ( 99m Tc-HDP) without either solid/visceral organ or soft tissue with multiple myeloma (MM) in skeletal scintigraphy. A 93-year-old man with hypertension and chronic heart failure for 14 years underwent bone scanning due to a 2-month history of back pain within a 1-year period of MM. Three hours later, 99m Tc-HDP late static images showed diffuse myocardial radiotracer accumulation and there were no other sites of abnormal soft tissue or visceral uptake. Myocardial accumulation had disappeared on 24-h delayed static images. This accumulation was thought to be related with AL-type amyloidosis associated with MM

Thyroid Scan and Uptake

Medline Plus

Full Text Available ... for a thyroid scan is 30 minutes or less. Thyroid Uptake You will be given radioactive iodine (I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake will begin several hours to 24 hours later. Often, two separate uptake ...

Intestinal uptake of bile acids: effect of external abdominal irradiation

International Nuclear Information System (INIS)

Thomson, A.B.R.; Cheeseman, C.I.; Walker, K.

1984-01-01

Abdominal irradiation has recently been shown to influence the uptake of hexoses, amino acids, fatty acids and cholesterol into the jejunum of rats. The present studies were undertaken with a previously validated in vitro technique to determine the effect of abdominal irradiation from a cesium source on the rates of uptake of six bile acids into the jejunum, ileum, and colon. The results show that: 1) there likely are multiple ileal carriers for bile acids: 2) abdominal irradiation has a variable effect on these carriers; 3) the passive permeability to bile acids varies with the bile acid and with the site along the intestine; and 4) abdominal irradiation is associated with a rise in the colonic permeability to only some bile acids

Radiostrontium uptake by plants from different soil types in Kazakhstan

Energy Technology Data Exchange (ETDEWEB)

Savinkov, A. [Scientific Research Agricultural Institute of the National Biotechnology Center, Ministry for Science and Higher Education of the Republic of Kazakhstan (SRAI), 480544, Gvardeiski (Kazakhstan)]. E-mail: Chebotar@srai.kz; Semioshkina, N. [GSF-Institut fuer Strahlenschutz, Ingolstaedter Land str.1, D-85764, Neuherberg (Germany)]. E-mail: semi@gsf.de; Howard, B.J. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom)]. E-mail: bjho@ceh.ac.uk; Voigt, G. [Agency' s Laboratories - Seibersdorf, IAEA, Vienna (Austria)]. E-mail: g.voigt@iaea.org

2007-02-01

The transfer of {sup 90}Sr to a range of different plant species grown on a range of different soil types in Kazakhstan, including three from the Semipalatinsk Test Site (STS), has been measured in a lysimeter experiment. {sup 90}Sr uptake by Stipa spp was significantly higher than for other vegetation species. The uptake of {sup 90}Sr from chernozem was significantly lower than that from the other soil types which is consistent with other literature. There was a significant negative relationship between {sup 90}Sr uptake and calcium, humus and CEC concentration in the soil for Agropyrum spp, Artemisia spp but not for Stipa spp or Bromus spp. The transfer to vegetation from soil has been quantified using the aggregated transfer coefficients for each species. Tag values range from 0.6 to 11.9 m{sup 2} kg {sup -1}x 10{sup -3} over all measurements. The transfer of {sup 90}Sr to plants from the Kazakh soils was low compared to previously reported data and to that given from literature reviews.

Surface determinants of low density lipoprotein uptake by endothelial cells

International Nuclear Information System (INIS)

Goeroeg, P.; Pearson, J.D.

1984-01-01

The surface sialic acid content of aortic endothelial cells in vitro was substantially lower in sparse cultures than at confluence. Binding of LDL to endothelial cells did not change at different culture densities and was unaffected by brief pretreatment with neuraminidase to partially remove surface sialic acid residues. In contrast, internalisation of LDL declined by a factor of 3 between low density cell cultures and confluent monolayers; neuraminidase pretreatment increased LDL uptake and the effect was most marked (>10-fold) at confluence. Pretreatment with cationised ferritin, which removed most of the surface sialic acid residues as well as glycosaminoglycans, increased LDL internalisation by up to 20-fold, again with most effect on confluent monolayers. Thus LDL uptake is inversely correlated with sialic acid content. We conclude that changes in the surface density of sialic acid (and possibly other charged) residues significantly modulate endothelial LDL uptake, and suggest that focal increases in LDL accumulation during atherogenesis may be related to alterations in endothelial endocytic properties at sites of increased cell turnover or damage. (author)

Plant-uptake of uranium: Hydroponic and soil system studies

Science.gov (United States)

Ramaswami, A.; Carr, P.; Burkhardt, M.

2001-01-01

Limited information is available on screening and selection of terrestrial plants for uptake and translocation of uranium from soil. This article evaluates the removal of uranium from water and soil by selected plants, comparing plant performance in hydroponic systems with that in two soil systems (a sandy-loam soil and an organic-rich soil). Plants selected for this study were Sunflower (Helianthus giganteus), Spring Vetch (Vicia sativa), Hairy Vetch (Vicia villosa), Juniper (Juniperus monosperma), Indian Mustard (Brassica juncea), and Bush Bean (Phaseolus nanus). Plant performance was evaluated both in terms of the percent uranium extracted from the three systems, as well as the biological absorption coefficient (BAC) that normalized uranium uptake to plant biomass. Study results indicate that uranium extraction efficiency decreased sharply across hydroponic, sandy and organic soil systems, indicating that soil organic matter sequestered uranium, rendering it largely unavailable for plant uptake. These results indicate that site-specific soils must be used to screen plants for uranium extraction capability; plant behavior in hydroponic systems does not correlate well with that in soil systems. One plant species, Juniper, exhibited consistent uranium extraction efficiencies and BACs in both sandy and organic soils, suggesting unique uranium extraction capabilities.

Influence of Prolonged Spaceflight on Heart Rate and Oxygen Uptake Kinetics

Science.gov (United States)

Hoffmann, U.; Moore, A.; Drescher, U.

2013-02-01

During prolonged spaceflight, physical training is used to minimize cardiovascular deconditioning. Measurement of the kinetics of cardiorespiratory parameters, in particular the kinetic analysis of heart rate, respiratory and muscular oxygen uptake, provides useful information with regard to the efficiency and regulation of the cardiorespiratory system. Practically, oxygen uptake kinetics can only be measured at the lung site (V’O2 resp). The dynamics of V’O2 resp, however, is not identical with the dynamics at the site of interest: skeletal muscle. Eight Astronauts were tested pre- and post-flight using pseudo random binary workload changes between 30 and 80 W. Their kinetic responses of heart rate, respiratory as well as muscular V’O2 kinetics were estimated by using time-series analysis. Statistical analysis revealed that the kinetic responses of respiratory as well as muscular V’O2 kinetics are slowed post-flight than pre-flight. Heart rate seems not to be influenced following flight. The influence of other factors (e. g. astronauts’ exercise training) may impact these parameters and is an area for future studies.

A preliminary evaluation of some soil and plant parameters that influence root uptake of arsenic, cadmium, cooper, and zinc

International Nuclear Information System (INIS)

Hattemer-Frey, H.A.; Krieger, G.R.; Lau, V.

1994-01-01

In the absence of site-specific data, the concentration of metals in plants is typically estimated by multiplying the total concentration of metal in soil by a metal-specific soil-to-root bioconcentration factor (BCF). However, this approach does not account for various soil properties, such as pH, organic matter content, and cation exchange capacity, that are known to influence root uptake of some metals. For risk assessment purposes, a simple, predictive method for estimating root uptake of metals that is based on site-specific soil and crop data is needed so that the importance of the produce ingestion pathway and subsequent influence on human exposure can be quantitatively assessed. An easy-to-use method is necessary since collecting site-specific data on the concentration of metals in home-grown produce is often time-consuming and costly. Ideally, it should be possible to develop a statistically-reliable relationship between plant and soil metals levels that includes appropriate weighing factors for various soil properties. Multiple linear regression analyses were used to develop simple, predictive models for estimating the concentration of metals in plants via root uptake using site-specific soil data. This paper presents preliminary predictive equations for estimating root uptake of arsenic, cadmium, copper, and zinc in fruiting, root, and all vegetables combined (i.e., fruiting and root crop data were combined). Results show that by using data on additional soil parameters (other than relying solely on the concentration of metals in soil), the concentration of metals in fruiting and root vegetables can be more confidently predicted

Tc-99m TRODAT uptake in an osteoid tumor of clivus.

Science.gov (United States)

Taywade, Sameer; Tripathi, Madhavi; Tandon, Vivek; Das, Chandan Jyoti; Damle, Nishikant Avinash; Shamim, Shamim Ahmed; Thukral, Parul; Bal, Chandrasekhar

2016-01-01

Tc-99m TRODAT is cocaine analog and binds to the dopamine transporter in vivo . Tc-99m TRODAT single-photon emission computed tomography/computed tomography. (SPECT/CT) is useful for demonstrating presynaptic dopaminergic dysfunction in patients with Parkinsonism. However, few reports have shown extrastriatal uptake of Tc-99m TRODAT. We present the case of a 67-year-old male who underwent Tc-99m TRODAT SPECT/CT for evaluation of Parkinsonism. In addition to tracer binding in the striatum, tracer uptake was noted in an osteoid tumor of the clivus. Integrated SPECT/CT enabled precise localization and characterization of the extrastriatal site of tracer binding and emphasizes the importance of such coincidental findings.

18F-FDG uptake assessed by PET/CT in abdominal aortic aneurysms is associated with cellular and molecular alterations prefacing wall deterioration and rupture.

Science.gov (United States)

Courtois, Audrey; Nusgens, Betty V; Hustinx, Roland; Namur, Gauthier; Gomez, Pierre; Somja, Joan; Defraigne, Jean-Olivier; Delvenne, Philippe; Michel, Jean-Baptiste; Colige, Alain C; Sakalihasan, Natzi

2013-10-01

Rupture of abdominal aortic aneurysms (AAAs) leads to a significant morbidity and mortality in aging populations, and its prediction would be most beneficial to public health. Spots positive for uptake of (18)F-FDG detected by PET are found in 12% of AAA patients (PET+), who are most often symptomatic and at high rupture risk. Comparing the (18)F-FDG-positive site with a negative site from the same aneurysm and with samples collected from AAA patients with no (18)F-FDG uptake should allow the discrimination of biologic alterations that would help in identifying markers predictive of rupture. Biopsies of the AAA wall were obtained from patients with no (18)F-FDG uptake (PET0, n = 10) and from PET+ patients (n = 8), both at the site positive for uptake and at a distant negative site of the aneurysmal wall. Samples were analyzed by immunohistochemistry, quantitative real-time polymerase chain reaction, and zymography. The sites of the aneurysmal wall with a positive (18)F-FDG uptake were characterized by a strikingly increased number of adventitial inflammatory cells, highly proliferative, and by a drastic reduction of smooth muscle cells (SMCs) in the media as compared with their negative counterpart and with the PET0 wall. The expression of a series of genes involved in the maintenance and remodeling of the wall was significantly modified in the negative sites of PET+, compared with the PET0 wall, suggesting a systemic alteration of the aneurysmal wall. Furthermore, a striking increase of several matrix metalloproteinases (MMPs), notably the MMP1 and MMP13 collagenases, was observed in the positive sites, mainly in the adventitia. Moreover, PET+ patients were characterized by a higher circulating C-reactive protein. Positive (18)F-FDG uptake in the aneurysmal wall is associated with an active inflammatory process characterized by a dense infiltrate of proliferating leukocytes in the adventitia and an increased circulating C-reactive protein. Moreover, a loss of SMC

Action of insecticidal N-alkylamides at site 2 of the voltage-sensitive sodium channel

International Nuclear Information System (INIS)

Ottea, J.A.; Payne, G.T.; Soderlund, D.M.

1990-01-01

Nine synthetic N-alkylamides were examined as inhibitors of the specific binding of [ 3 H]batrachotoxinin A 20α-benzoate ([ 3 H]BTX-B) to sodium channels and as activators of sodium uptake in mouse brain synaptoneurosomes. In the presence of scorpion (Leiurus quinquestriatus) venom, the six insecticidal analogues were active as both inhibitors of [ 3 H]BTX-B binding and stimulators of sodium uptake. These findings are consistent with an action of these compounds at the alkaloid activator recognition site (site 2) of the voltage-sensitive sodium channel. The three noninsecticidal N-alkylamides also inhibited [ 3 H]BTX-B binding but were ineffective as activators of sodium uptake. Concentration-response studies revealed that some of the insecticidal amides also enhanced sodium uptake through a second, high-affinity interaction that does not involve site 2, but this secondary effect does not appear to be correlated with insecticidal activity. The activities of N-alkylamides as sodium channel activators were influenced by the length of the alkenyl chain and the location of unsaturation within the molecule. These results further define the actions of N-alkylamides on sodium channels and illustrate the significance of the multiple binding domains of the sodium channel as target sites for insect control agents

Cloning, expression, and characterization of cadmium and manganese uptake genes from Lactobacillus plantarum

Energy Technology Data Exchange (ETDEWEB)

Hao, Z.; Chen, S.; Wilson, D.B.

1999-11-01

An Mn{sup 2+} and Cd{sup 2+} uptake gene, mntA, was cloned from Lactobacillus plantarum ATCC 14917 into Escherichia coli. Its expression conferred on E. coli cells increased Cd{sup 2+} sensitivity as well as energy-dependent Cd{sup 2+} uptake activity. Both transcription and translation of mntA were induced by Mn{sup 2+} starvation in L. plantarum, as indicated by reverse transcriptase PCR and immunoblotting. Two Cd{sup 2+} uptake systems have been identified in L. plantarum: one is a high-affinity Mn{sup 2+} and Cd{sup 2+} uptake system that is expressed in Mn{sup 2+}-starved cells, and the other is a nonsaturable Cd{sup 2+} uptake system that is expressed in Cd{sup 2+}-sufficient cells. MntA was not detected in an Mn{sup 2+}-dependent mutant of L. plantarum which had lost high-affinity Mn{sup 2+} and Cd{sup 2+} uptake activity. The results suggest that mntA is the gene encoding the high-affinity Mn{sup 2+} and Cd{sup 2+} transporter. On the basis of its predicted amino acid sequence, MntA belongs to the family of P-type cation-translocating ATPases. The topology and potential Mn{sup 2+}- and Cd{sup 2+}-binding sites of MntA are discussed. A second clone containing a low-affinity Cd{sup 2+} transport system was also isolated.

Further studies on the nature of postsynaptic dopamine uptake and metabolism in rat striatum: sodium dependency and investigation of a possible role for carrier-mediated uptake into serotonin neurons

Energy Technology Data Exchange (ETDEWEB)

Schoepp, D.D.; Azzaro, A.J.

1985-06-01

The nature of postsynaptic sites involved in the uptake and metabolism of striatal 3,4-dihydroxyphenylethylamine (dopamine, DA) was investigated. The accumulation of (/sup 3/H)DA (10(-7) M) into slices of rat striatum was found to be greatly dependent on the presence of sodium ion in the incubation medium. However, the formation of the (/sup 3/H)dihydroxyphenylacetic acid (DOPAC) and (/sup 3/H)homovanillic acid (HVA) was only partially reduced in the absence of sodium. Inhibition of carrier-mediated DA neuronal uptake with nomifensine significantly decreased DA accumulation (18% of control) and (/sup 3/H)DOPAC formation (62% of control), but enhanced (/sup 3/H)HVA production (143% of control). Inhibition of the 5-hydroxytryptamine (5-HT, serotonin) neuronal uptake system with fluoxetine (10(-6) M) or selective 5-HT neuronal lesions with 5,7-dihydroxytryptamine (5,7-DHT) had no effect on (/sup 3/H)DOPAC or (/sup 3/H)HVA formed from (/sup 3/H)DA in the presence or absence of nomifensine. These results demonstrate that the uptake and subsequent metabolism of striatal DA to DOPAC and HVA is only partially dependent on carrier-mediated uptake mechanism(s) requiring sodium ion. These data support our previous findings suggesting a significant role for synaptic glial cell deamination and O-methylation of striatal DA. Further, experiments with fluoxetine or 5,7-DHT suggest that 5-HT neurons do not significantly contribute in the synaptic uptake and metabolism of striatal DA.

Uptake of nuclides by plants

International Nuclear Information System (INIS)

Greger, Maria

2004-04-01

This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate

Uptake of nuclides by plants

Energy Technology Data Exchange (ETDEWEB)

Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

2004-04-01

This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate.

Instrumental neutron activation analysis of site-dependent uptake and distribution of trace elements in the saltmarsh plant Aster tripolium from marsh fields in the Schelde estuary, Netherlands

International Nuclear Information System (INIS)

Rossbach, M.

1986-07-01

As part of an environmental chemical investigation the uptake of heavy metals by a saltmarsh plant Aster tripolium from two differently polluted salt marsh sites of the North Sea between 20 to 30 trace elements were determined in soil and plant organs. A sensitive gamma ray counting system was installed and tested for instrumental activation analyses (INAA). Installations to improve sensitivity as well as conditions necessary for reliable trace element analysis with the aid of Anticompton spectrometers (ACS) are described. The accuracy and reproducibility of the method was determined by the analysis of reference- and control materials of the german environmental specimen bank. In order to characterise the state of pollution of the salt marsh soils pollution-factors for single elements as well as interelemental correlations were evaluated. In addition, uptake and translocation factors of the biological samples were calculated. The many highly significant correlations between elements within the plant organs indicated that uptake appears to be physiologicaly controlled and not dependent on soil concentration. In order to detect further consequences of differing pollution influences within these plants biochemical separation techniques were applied and trace element levels in selected extracts were determined. For the specification of heavy metals gelpermeation chromatography of ethanolic extracts proved to be the most promising method. Furthermore, propositions for the use of trace elements as a fingerprint for pollution status and characterisation of species for referenz- and specimenbank materials have been developed. Aster tripolium as a cadmium accumulating plant can probably be used as an indicator in the monitoring of cadmium polluted salt marsh areas. (orig.) [de

Behavioral and biochemical effects of the antidepressant bupropion (Wellbutrin): evidence for selective blockade of dopamine uptake in vivo.

Science.gov (United States)

Cooper, B R; Hester, T J; Maxwell, R A

1980-10-01

Bupropion (BW 323U; Wellbutrin), a novel compound with antidepressant effects in man, was found to reduce immobility in an "experimental helplessness" forced swimming antidepressant test in rats as did imipramine and amitriptyline. Higher doses produced elevated locomotor activity in an automated open field and produced stereotyped sniffing which was contrasted with apomorphine. When bupropion or desmethylimipramine was given before intracisternal injections of 6-hydroxydopamine, bupropion produced a dose-related selective antagonism of the destruction of dopamine neurons, while under the same conditions, desmethylimipramine produced a dose-related selective antagonism of the destruction of noradrenergic neurons. Studies in which the dose of bupropion and the dose of 6-hydroxydopamine were varied revealed that a dose-related selective antagonism of dopamine depletion by 6-hydroxydopamine occurred when doses up to and including 50 mg/kg i.p. to bupropion were administered. Some antagonism of norepinephrine depletion also occurred at 100 mg/kg of bupropion i.p. Bupropion also selectively reversed the dopamine depletion produced by alpha-methyl-m-tyrosine, a finding which is consistent with the view that bupropion is a dopamine uptake inhibitor in vivo. The importance of dopamine systems for the behavioral effects of bupropion were also studied. When the locomotor stimulant effects of bupropion were tested in rats with chronic destruction of dopamine neurons produced by 6-hydroxydopamine, bupropion failed to elevate locomotor activity. Rats treated with procedures using 6-hydroxydopamine to produce relatively selective norepinephrine depletions responded to bupropion with locomotor activity stimulation like controls. Rats with similar depletions of either dopamine or norepinephrine were also tested for the ability of low doses of bupropion to reduce immobility in the "experimental helplessness" forced swim antidepressant test. Prior destruction of dopamine neurons

Potential NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species

Energy Technology Data Exchange (ETDEWEB)

Jauhiainen, J [Joensuu Univ. (Finland). Dept. of Biology; Wallen, B; Malmer, N [Lund Univ. (Sweden). Dept. of Plant Ecology

1997-12-31

The objective of this research is to test differences in NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species under laboratory conditions. The studied species represent two gradients: the minerotrophy-ombrotrophy (mire margin - mire expanse) gradient, and the hummock-hollow gradient. There are distinct differences in the uptake rate between various Sphagnum species and these differences seem to be due to both structural and environmental factors: (1) on individual basis the highest uptake rate is in species with large capitulum and high number of ion exchange sites i.e. lawn species, (2) on dry mass basis the most effective species are the hummock species though they have a low DM, (3) from the ecosystem point of view, hummock species with high number of shoots per unit area and high uptake rate on dry mass basis, are the most effective species in filtering available nitrogen. (1 ref.)

Potential NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species

Energy Technology Data Exchange (ETDEWEB)

Jauhiainen, J. [Joensuu Univ. (Finland). Dept. of Biology; Wallen, B.; Malmer, N. [Lund Univ. (Sweden). Dept. of Plant Ecology

1996-12-31

The objective of this research is to test differences in NH{sub 4}{sup +} and NO{sub 3}{sup -} uptake on various Sphagnum species under laboratory conditions. The studied species represent two gradients: the minerotrophy-ombrotrophy (mire margin - mire expanse) gradient, and the hummock-hollow gradient. There are distinct differences in the uptake rate between various Sphagnum species and these differences seem to be due to both structural and environmental factors: (1) on individual basis the highest uptake rate is in species with large capitulum and high number of ion exchange sites i.e. lawn species, (2) on dry mass basis the most effective species are the hummock species though they have a low DM, (3) from the ecosystem point of view, hummock species with high number of shoots per unit area and high uptake rate on dry mass basis, are the most effective species in filtering available nitrogen. (1 ref.)

Positron imaging feasibility studies: characteristics of [3H]thymidine uptake in rodent and canine neoplasms

International Nuclear Information System (INIS)

Larson, S.M.; Weiden, P.L.; Grunbaum, J.

1981-01-01

Uptake [ 3 H]thymidine was studied in BALB/c mice with EMT-6 sarcoma, in Buffalo rats with Morris 7777 hepatoma, and in nine dogs with spontaneous neoplasms: four lymphomas, two osteosarcomas, two soft-tissue sarcomas, and a thyroid carcinoma. High tumor-to-tissue ratios were observed for all tumor types assayed, and absolute uptakes, when computed as percent dose per gram tumor normalized for body weight, were similar for transplanted and spontaneous tumors. In the rodent tumors, radiothymidine was retained for at least 3 hr in the tumor without appreciable loss. In canine neoplasms, although the highest uptakes were observed in cellular tumors with many mitotic figures, tumor uptake showed significant variability that did not correlate with any obvious histologic change, and thus may reflect true biologic differences in metabolism among tumors at different sites in the same animal. These studies provide additional experimental evidence that the ratios of neoplastic to normal tissue and the kinetics of thymidine uptake by tumors are suitable for positron emission tomography of neoplasms in small and large, animals, including both transplanted and spontaneous tumors

Grass species influence on plant N uptake - Determination of atmospheric N deposition to a semi-natural peat bog site using a 15N labelling approach

Science.gov (United States)

Hurkuck, Miriam; Brümmer, Christian; Spott, Oliver; Flessa, Heinz; Kutsch, Werner L.

2014-05-01

Large areas of natural peat bogs in Northwestern Germany have been converted to arable land and were subjected to draining and peat cutting in the past. The few protected peatland areas remaining are affected by high nitrogen (N) deposition. Our study site - a moderately drained raised bog - is surrounded by highly fertilized agricultural land and livestock production. In this study, we used a 15N pool dilution technique called 'Integrated Total Nitrogen Input' (ITNI) to quantify annual deposition of atmospheric N into biomonitoring pots over a two-year period. Since it considers direct N uptake by plants, it was expected to result in higher N input than conventional methods for determination of N deposition (e.g. micrometeorological approaches, bulk N samplers). Using Lolium multiflorum and Eriophorum vaginatum as monitor plants and low, medium and high levels of fertilization, we aimed to simulate increasing N deposition to planted pots and to allocate airborne N after its uptake by the soil-plant system in aboveground biomass, roots and soil. Increasing N fertilization was positively correlated with biomass production of Eriophorum vaginatum, whereas atmospheric plant N uptake decreased and highest airborne N input of 899.8 ± 67.4 µg N d-1 pot-1 was found for low N fertilization. In contrast, Lolium multiflorum showed a clear dependency of N supply on plant N uptake and was highest (688.7 ± 41.4 µg N d-1 pot-1) for highly fertilized vegetation pots. Our results suggest that grass species respond differently to increasing N input. While crop grasses such as Lolium multiflorum take up N according to N availability, species adopted to nutrient-limited conditions like Eriophorum vaginatum show N saturation effects with increasing N supply. Total airborne N input ranged from about 24 to 66 kg N ha-1 yr-1 dependent on the used indicator plant and the amount of added fertilizer. Parallel determination of atmospheric N deposition using a micrometeorological approach

Uptake of inflammatory cell marker [{sup 11}C]PK11195 into mouse atherosclerotic plaques

Energy Technology Data Exchange (ETDEWEB)

Laitinen, Iina; Marjamaeki, Paeivi; Naagren, Kjell; Roivainen, Anne; Knuuti, Juhani [University of Turku, Turku PET Centre, Turku (Finland); Laine, V.J.O. [Turku University Hospital, Department of Pathology, Turku (Finland); Wilson, Ian [GE Healthcare Biosciences, Medical Diagnostics, London (United Kingdom); Leppaenen, Pia; Ylae-Herttuala, Seppo [University of Kuopio, A.I. Virtanen Institute, Kuopio (Finland)

2009-01-15

The ligand [{sup 11}C]PK11195 binds with high affinity and selectivity to peripheral benzodiazepine receptor, expressed in high amounts in macrophages. In humans, [{sup 11}C]PK11195 has been used successfully for the in vivo imaging of inflammatory processes of brain tissue. The purpose of this study was to explore the feasibility of [{sup 11}C]PK11195 in imaging inflammation in the atherosclerotic plaques. The presence of PK11195 binding sites in the atherosclerotic plaques was verified by examining the in vitro binding of [{sup 3}H]PK11195 onto mouse aortic sections. Uptake of intravenously administered [{sup 11}C]PK11195 was studied ex vivo in excised tissue samples and aortic sections of a LDLR/ApoB48 atherosclerotic mice. Accumulation of the tracer was compared between the atherosclerotic plaques and non-atherosclerotic arterial sites by autoradiography and histological analyses. The [{sup 3}H]PK11195 was found to bind to both the atherosclerotic plaques and the healthy wall. The autoradiography analysis revealed that the uptake of [{sup 11}C]PK11195 to inflamed regions in plaques was more prominent (p = 0.011) than to non-inflamed plaque regions, but overall it was not higher than the uptake to the healthy vessel wall. Also, the accumulation of {sup 11}C radioactivity into the aorta of the atherosclerotic mice was not increased compared to the healthy control mice. Our results indicate that the uptake of [{sup 11}C]PK11195 is higher in inflamed atherosclerotic plaques containing a large number of inflammatory cells than in the non-inflamed plaques. However, the tracer uptake to other structures of the artery wall was also prominent and may limit the use of [{sup 11}C]PK11195 in clinical imaging of atherosclerotic plaques. (orig.)

DOC:NO3- ratios and NO3- uptake in forested headwater streams

Science.gov (United States)

Rodríguez-Cardona, Bianca; Wymore, Adam S.; McDowell, William H.

2016-01-01

The underlying mechanisms driving the coupled interactions between inorganic nitrogen uptake and dissolved organic matter are not well understood, particularly in surface waters. To determine the relationship between dissolved organic carbon (DOC) quantity and nitrate (NO3-) uptake kinetics in streams, we performed a series of NO3- Tracer Additions for Spiraling Curve Characterization experiments in four streams within the Lamprey River Watershed, New Hampshire, across a range in background DOC concentrations (1-8 mg C/L). Experiments were performed throughout the 2013 and 2014 growing seasons. Across streams and experimental dates, ambient uptake velocity (Vf) correlated positively with increasing DOC concentrations and DOC:NO3- ratios but was only weakly negatively associated with NO3- concentrations. Ambient NO3- Vf was unrelated to pH, light, temperature, dissolved oxygen, and Specific Ultraviolet Absorbance at 254 nm. Although there were general tendencies across the entire Lamprey River Watershed, individual sites behaved differently in their uptake kinetics. NO3- uptake dynamics in the Lamprey River Watershed are most strongly influenced by DOC concentrations rather than NO3- concentrations or physicochemical parameters, which have been identified as regional- to continental-scale drivers in previous research. Understanding the fundamental relationships between dissolved organic matter and inorganic nutrients will be important as global and climatic changes influence the delivery and production of DOC and NO3- in aquatic ecosystems.

Relationship between local cerebral glucose uptakes, serum prolactin, growth hormone and cortisol levels changes during epilepsy

International Nuclear Information System (INIS)

Wang Mingfang; Mao Xianghui; Tang Ganghua; Zhao Jun; Sun Aijun

2002-01-01

Objective: To explore the relation of local cerebral FDG uptake value of glucose to the changes of prolactin (PRL), growth hormone (GH) and cortisol levels in serum during epilepsy. Methods: 76 epileptic patients with solitary epileptic focus were examined by 2-deoxy-2-[ 18 F] fluoro-D-glucose ( 18 F-FDG) positron emission tomography (PET) imaging and the FDG uptake value of epileptic foci were measured. Serum PRL, GH and cortisol levels of the patients were determined by radioimmunoassay (RIA) before and after seizures. Results: During ictal studies, all patients showed increased FDG uptake of epileptic foci compared with that in interictal phase. The serum PRL, GH and cortisol levels were significant higher after seizures. The changes of hormone levels correlated significantly with the lengths of seizure free intervals (SFIs) and with the types of seizures. But the variations of hormone levels had no relation with the site and FDG uptake of epileptic foci. In patients with absentia seizures, no significant increase was observed in serum PRL and cortisol levels. The changes of GH were not related with the types of seizures. Also, it was found that changes of hormone levels had significant relations to the lengths of SFIs. Conclusions: Serum PRL, GH and cortisol levels were significantly different before and after seizures. This study suggests that changes of postictal hormone levels correlated significantly with the types of seizures and lengths of SFIs, but the changes of hormone levels are not related with the site and FDG uptake of epileptic foci

Diselenolane-mediated cellular uptake.

Science.gov (United States)

Chuard, Nicolas; Poblador-Bahamonde, Amalia I; Zong, Lili; Bartolami, Eline; Hildebrandt, Jana; Weigand, Wolfgang; Sakai, Naomi; Matile, Stefan

2018-02-21

The emerging power of thiol-mediated uptake with strained disulfides called for a move from sulfur to selenium. We report that according to results with fluorescent model substrates, cellular uptake with 1,2-diselenolanes exceeds uptake with 1,2-dithiolanes and epidithiodiketopiperazines with regard to efficiency as well as intracellular localization. The diselenide analog of lipoic acid performs best. This 1,2-diselenolane delivers fluorophores efficiently to the cytosol of HeLa Kyoto cells, without detectable endosomal capture as with 1,2-dithiolanes or dominant escape into the nucleus as with epidithiodiketopiperazines. Diselenolane-mediated cytosolic delivery is non-toxic (MTT assay), sensitive to temperature but insensitive to inhibitors of endocytosis (chlorpromazine, methyl-β-cyclodextrin, wortmannin, cytochalasin B) and conventional thiol-mediated uptake (Ellman's reagent), and to serum. Selenophilicity, the extreme CSeSeC dihedral angle of 0° and the high but different acidity of primary and secondary selenols might all contribute to uptake. Thiol-exchange affinity chromatography is introduced as operational mimic of thiol-mediated uptake that provides, in combination with rate enhancement of DTT oxidation, direct experimental evidence for existence and nature of the involved selenosulfides.

Diffuse Myocardial Uptake of {sup 99m}Tc-HDP in Multiple Myeloma

Energy Technology Data Exchange (ETDEWEB)

Demirel, Koray; Sadic, Murat; Korkmaz, Meliha; Comak, Aylin; Atilgan, Hasan Ikbal; Koca, Goekhan [Ministry of Health Ankara Training and Research Hospital, Ankara (Turkmenistan)

2013-09-15

Soft tissue uptake is a rare finding in bone scintigraphy, with an incidence of 2%. Although the mechanism has not yet been fully clarified, several causes have been reported for this unusual uptake pattern. This paper presents a case of diffuse myocardial accumulation of technetium-99m hydroxymethylene diphosphonate ({sup 99m}Tc-HDP) without either solid/visceral organ or soft tissue with multiple myeloma (MM) in skeletal scintigraphy. A 93-year-old man with hypertension and chronic heart failure for 14 years underwent bone scanning due to a 2-month history of back pain within a 1-year period of MM. Three hours later, {sup 99m}Tc-HDP late static images showed diffuse myocardial radiotracer accumulation and there were no other sites of abnormal soft tissue or visceral uptake. Myocardial accumulation had disappeared on 24-h delayed static images. This accumulation was thought to be related with AL-type amyloidosis associated with MM.

Soil and vegetation influence in plants natural radionuclides uptake at a uranium mining site

Science.gov (United States)

Charro, E.; Moyano, A.

2017-12-01

The main objective of this work is to investigate the uptake of several radionuclides by the vegetation characteristic of a dehesa ecosystem in uranium mining-impacted soils in Central-West of Spain. The activity concentration for 238U, 226Ra, 210Pb, 232Th, and 224Ra was measured in soil and vegetation samples using a Canberra n-type HPGe gamma-ray spectrometer. Transfer factors of natural radionuclides in different tissues (leaves, branches, twigs, and others) of native plants were evaluated. From these data, the influence of the mine, the physicochemical parameters of the soils and the type of vegetation were analyzed in order to explain the accumulation of radionuclides in the vegetation. A preferential uptake of 210Pb and 226Ra by plants, particularly by trees of the Quercus species (Quercus pyrenaica and Quercus ilex rotundifolia), has been observed, being the transfer factors for 226Ra and 210Pb in these tree species higher than those for other plants (like Pinus pinaster, Rubur ulmifolius and Populus sp.). The analysis of radionuclide contents and transfer factors in the vegetation showed no evidence of influence of the radionuclide concentration in soils, although it could be explained in terms of the type of plants and, in particular, of the tree's species, with special attention to the tree's rate of growth, being higher in slow growing species.

Effect of arbuscular mycorrhizal (AM) fungi on 137Cs uptake by plants grown on different soils

International Nuclear Information System (INIS)

Vinichuk, M.; Mårtensson, A.; Ericsson, T.; Rosén, K.

2013-01-01

The potential use of mycorrhiza as a bioremediation agent for soils contaminated by radiocesium was evaluated in a greenhouse experiment. The uptake of 137 Cs by cucumber, perennial ryegrass, and sunflower after inoculation with a commercial arbuscular mycorrhizal (AM) product in soils contaminated with 137 Cs was investigated, with non-mycorrhizal quinoa included as a “reference” plant. The effect of cucumber and ryegrass inoculation with AM fungi on 137 Cs uptake was inconsistent. The effect of AM fungi was most pronounced in sunflower: both plant biomass and 137 Cs uptake increased on loamy sand and loamy soils. The total 137 Cs activity accumulated within AM host sunflower on loamy sand and loamy soils was 2.4 and 3.2-fold higher than in non-inoculated plants. Although the enhanced uptake of 137 Cs by quinoa plants on loamy soil inoculated by the AM fungi was observed, the infection of the fungi to the plants was not confirmed. - Highlights: ► Effect of soil inoculation on 137 Cs uptake by crops was studied in greenhouse. ► 137 Cs uptake by inoculated sunflower plants was most pronounced. ► The higher 137 Cs uptake by inoculated sunflower due to presence of mycorrhiza. ► Studies suggest potential for use of mycorrhiza on contaminated sites.

Light Conditions Affect the Measurement of Oceanic Bacterial Production via Leucine Uptake

Science.gov (United States)

Morán, Xosé Anxelu G.; Massana, Ramon; Gasol, Josep M.

2001-01-01

The effect of irradiance in the range of 400 to 700 nm or photosynthetically active radiation (PAR) on bacterial heterotrophic production estimated by the incorporation of 3H-leucine (referred to herein as Leu) was investigated in the northwestern Mediterranean Sea and in a coastal North Atlantic site, with Leu uptake rates ranging over 3 orders of magnitude. We performed in situ incubations under natural irradiance levels of Mediterranean samples taken from five depths around solar noon and compared them to incubations in the dark. In two of the three stations large differences were found between light and dark uptake rates for the surfacemost samples, with dark values being on average 133 and 109% higher than in situ ones. Data obtained in coastal North Atlantic waters confirmed that dark enclosure may increase Leu uptake rates more than threefold. To explain these differences, on-board experiments of Leu uptake versus irradiance were performed with Mediterranean samples from depths of 5 and 40 m. Incubations under a gradient of 12 to 1,731 μmol of photons m−2 s−1 evidenced a significant increase in incorporation rates with increasing PAR in most of the experiments, with dark-incubated samples departing from this pattern. These results were not attributed to inhibition of Leu uptake in the light but to enhanced bacterial response when transferred to dark conditions. The ratio of dark to light uptake rates increased as dissolved inorganic nitrogen concentrations decreased, suggesting that bacterial nutrient deficiency was overcome by some process occurring only in the dark bottles. PMID:11525969

Physiological and tumoral uptake of 68Ga-DOTATATE. Standardized uptake values and challenges in interpretation

International Nuclear Information System (INIS)

Kuyumcu, Serkan; Oezkan, Zeynep Goezde; Sanli, Yasemin; Yilmaz, Ebru; Mudun, Ayse; Adalet, Isik; Unal, Seher

2013-01-01

The objective of this study is to determine the range of standardized uptake value (SUV) max of 68Ga-DOTA-tyr3-octreotate (DOTATATE) in normal organs and tumoral lesions and establish uptake unrelated to neuroendocrine tumors (NET). One hundred and twenty patients (57 men, 63 women), who underwent 68 Ga-DOTATATE positron emission tomography (PET)/CT imaging in our institution were analyzed. Patients were indicated for 68 Ga-DOTATATE PET/CT imaging to detect primary tumor or metastasis of suspected or previously known NET, to determine somatostatin receptor (SSTR) positivity and to detect occult source of ectopic Cushing syndrome. Normal range of uptake was calculated for the organs that were proven to have no pathology by either conventional radiological imaging or clinical follow-up, using SUV max as a semiquantitative measure. Uptake and tumor to background (T/B) ratios of tumoral lesions in liver, pancreas, bone, brain and lymph nodes were calculated. Uptakes due to lesions unrelated to NET were also documented. Significant uptake was found in spleen, kidneys, adrenal glands, liver and pituitary gland with mean SUV max of 24.67, 14.30, 13.73, 9.12 and 9.74 respectively. Uptake was measured separately for the pancreatic head and body separately, however, besides a slightly heterogeneous uptake; the difference was not statistically significant. Uptake in the tumoral lesions had high (T/B) ratios with mean SUV max of 28.72, 25.21, 18.28, 34.73 and 12.59 for liver, pancreas, bone, brain and lymph nodes, respectively. Incidental benign tumoral lesions were detected in 3 patients (2.5%) which were meningioma and fibrous dysplasia demonstrating significant and breast fibroadenoma demonstrating mild 68 Ga-DOTATATE uptake. Non-neoplastic processes were detected in 4 patients (14.1%), including postsurgical inflammation, reactive lymph nodes, arthritis and demonstrated faint to mild 68 Ga-DOTATATE uptake, with the exception of significant uptake in accessory spleen. 68 Ga

Improved hydrogen production by uptake hydrogenase deficient mutant strain of Rhodobacter sphaeroides O.U.001

Energy Technology Data Exchange (ETDEWEB)

Kars, Goekhan; Guenduez, Ufuk; Yuecel, Meral [Department of Biological Sciences, Middle East Technical University, 06531 Ankara (Turkey); Rakhely, Gabor; Kovacs, Kornel L. [Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Szeged (Hungary); Eroglu, Inci [Department of Chemical Engineering, Middle East Technical University, 06531 Ankara (Turkey)

2008-06-15

Rhodobacter sphaeroides O.U.001 is a purple non-sulfur bacterium producing hydrogen under photoheterotrophic conditions. Hydrogen is produced by Mo-nitrogenase enzyme and substantial amount of H{sub 2} is reoxidized by a membrane-bound uptake hydrogenase in the wild type strain. To improve the hydrogen producing capacity of the cells, a suicide vector containing a gentamicin cassette in the hupSL genes was introduced into R. sphaeroiodes O.U.001 and the uptake hydrogenase genes were destroyed by site directed mutagenesis. The correct integration of the construct was confirmed by uptake hydrogenase activity measurement, PCR and subsequent sequence analysis. The wild type and the mutant cells showed similar growth patterns but the total volume of hydrogen gas evolved by the mutant was 20% higher than that of the wild type strain. This result demonstrated that the hydrogen produced by the nitrogenase was not consumed by uptake hydrogenase leading to higher hydrogen production. (author)

{sup 18}F-FDG uptake at the surgical margin after hepatic resection: Patterns of uptake and differential diagnosis

Energy Technology Data Exchange (ETDEWEB)

Peungjesada, Silanath [University New Mexico, Department of Radiology, Albuquerque, NM (United States); Aloia, Thomas A. [University of Texas MD Anderson Cancer Center, Department of Surgical Oncology, Unit 444, Houston, TX (United States); Fox, Patricia [University of Texas MD Anderson Cancer Center, Department of Biostatistics, Unit 1411, Houston, TX (United States); Chasen, Beth [University of Texas MD Anderson Cancer Center, Department of Nuclear Medicine, Unit 1483, Houston, TX (United States); Shin, Sooyoung; Loyer, Evelyne M. [University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Unit 1473, Houston, TX (United States); Baiomy, Ali [Cairo University, National Cancer Center, Cairo (Egypt)

2015-08-15

To evaluate the patterns of {sup 18}F-FDG uptake at the surgical margin after hepatectomy to identify features that may differentiate benign and malignant uptake. Patients who had undergone a PET/CT after hepatectomy were identified. Delay between resection and PET/CT, presence of uptake at the surgical margin, pattern of uptake, and maximal standardized value were recorded. The PET/CT findings were correlated with contrast-enhanced CT or MRI. There were 26 patients with increased 18F-FDG uptake; uptake was diffuse in seven and focal in 19. Diffuse uptake was due to inflammation in all cases. Focal uptake was due to recurrence in 12 and inflammation in seven cases. Defining a focal pattern only as a positive for malignancy yielded 100 % sensitivity, 87 % specificity, 37 % false positive rate. As expected, SUV{sub max} was significantly higher for recurrence than inflammation, but did overlap. Contrast-enhanced CT allowed differentiation between malignant and benign uptake in all cases. F-FDG uptake after hepatectomy does not equate to recurrence and yields a high false positive rate. Diffuse uptake did not require additional evaluation in our sample. Focal uptake, however, may be due to recurrence; differentiating benign and malignant nodular uptake relies on optimal contrast-enhanced CT or MRI. (orig.)

Persistent non-specific FDG uptake on PET imaging following hip arthroplasty

Energy Technology Data Exchange (ETDEWEB)

Zhuang, Hongming; Chacko, Thomas K.; Hickeson, Marc; Stevenson, Karen; Feng, Qi; Ponzo, Fabio; Alavi, Abass [Division of Nuclear Medicine, Department of Radiology, The Hospital of University of Pennsylvania, 110 Donner Building, 3400 Spruce Street, Philadelphia, PA 19104 (United States); Garino, Jonathan P. [Department of Orthopedic Surgery, The Hospital of University of Pennsylvania, Philadelphia, PA 19802 (United States)

2002-10-01

Hip arthroplasty is a common surgical procedure, but the diagnosis of infection associated with hip arthroplasty remains challenging. Fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) has been shown to be a promising imaging modality in settings where infection is suspected. However, inflammatory reaction to surgery can result in increased FDG uptake at various anatomic locations, which may erroneously be interpreted as sites of infection. The purpose of this study was to assess the patterns and time course of FDG accumulation following total hip replacement over an extended period of time. Firstly, in a prospective study nine patients with total hip replacement were investigated to determine the patterns of FDG uptake over time. Three FDG-PET scans were performed in each patient at about 3, 6 and 12 months post arthroplasty. Secondly, in a retrospective analysis, the medical and surgical history and FDG-PET imaging results of 710 patients who had undergone whole-body scans for the evaluation of possible malignant disorders were reviewed. The history of arthroplasty and FDG-PET findings in the hip region were reviewed for this study. Patients with symptomatic arthroplasties or related complaints during FDG-PET scanning were excluded from the analysis. During the entire study period, all nine patients enrolled in the prospective study were demonstrated to have increased FDG uptake around the femoral head or neck portion of the prosthesis that extended to the soft tissues surrounding the femur. Among the patients reviewed in the retrospective study, 18 patients with a history of 21 hip arthroplasties who were asymptomatic at the time of FDG-PET scan met the criteria for inclusion. The time interval between the hip arthroplasty and the FDG-PET study ranged from 3 months to 288 months (mean{+-}SD: 80.4{+-}86.2 months). In 81% (17 of 21) of these prostheses, increased FDG uptake could be noted around the femoral head or neck portion of the

Examining College Students' Uptake of Facebook through the Lens of Domestication Theory

Science.gov (United States)

Lohnes Watulak, Sarah; Whitfield, Dean

2016-01-01

Given the prevalence of social network sites (SNS) uptake among college students, and Facebook use in particular, we seek to understand the variety of ways in which Facebook is embedded in the routine, everyday lives of undergraduates. In addition to Facebook use, we aim to shed light on non-use; why do some American undergraduates choose to use…

Uptake of polychlorinated biphenyls and organochlorine pesticides from soil and air into radishes (Raphanus sativus)

DEFF Research Database (Denmark)

Mikes, Ondrej; Cupr, P.; Trapp, Stefan

2009-01-01

Uptake of organochlorine pesticides and polychlorinated biphenyls from soil and air into radishes was measured at a heavily contaminated field site. The highest contaminant concentrations were found for DDT and its metabolites, and for beta-hexachlorocyclohexane. Bioconcentration factor (BCF, def...

Effects of cadmium on the uptake of dopamine and norepinephrine in rat brain synaptosomes

International Nuclear Information System (INIS)

Anon.

1986-01-01

Cadmium (Cd) a known environmental contaminant is neurotoxic. Kinetics of cadmium inhibition indicate that the metal may compete with ATP and Na + sites on Na + -K + ATPase in rat brain synaptosomes. Uptake and release processes of catecholamines into the central nervous system are dependent on membrane bound Na + -K + ATPase. It is suggested that the uptake and release processes of dopamine (DA) and norepinephrine (NE) in neurons are energy utilizing and hence are dependent on active ion transport. If the two aforementioned mechanisms are truly interdependent, then any alteration caused by a toxin to either of the above two mechanisms should also cause a parallel change in the other. The purpose of this study was to examine in vitro effects of cadmium chloride on the uptake of DA and NE and the activity of ATPase in the rat brain synaptosome

A mechanism for the hydrogen uptake process in zirconium alloys

International Nuclear Information System (INIS)

Cox, B.

1999-01-01

Hydrogen uptake data for thin Zircaloy-2 specimens in steam at 300-400 C have been analysed to show that there is a decrease in the rate of uptake with respect to the rate of oxidation when the terminal solid solubility (TSS) of hydrogen in the metal is exceeded. In order for TSS to be reached during pre-transition oxidation a very thin 0.125 mm Zircaloy sheet was used. The specimens had been pickled initially removing all Zr 2 (Fe/Ni) particles from the initial surfaces, yet the initial hydrogen uptake rates were still much higher than for Zircaloy-4 or a binary Zr/Fe alloy that did not contain phases that dissolve readily during pickling. Cathodic polarisation at room temperature in CuSO 4 solution showed that small cracks or pores formed the cathodic sites in pre-transition oxide films. Some were at pits resulting from the initial dissolution of the Zr 2 (Fe/Ni) phase; others were not; none were at the remaining intermetallics in the original surface. These small cracks are thought to provide the ingress routes for hydrogen. A microscopic steam starvation process at the bottoms of these small cracks or pores, leading to the accumulation of hydrogen adjacent to the oxide/metal interface, and causing breakdown of the passive oxide forming at the bottom of the flaw, is thought to provide the mechanism for the hydrogen uptake process during both pre-transition and post-transition oxidation. (orig.)

Uptake of polychlorinated biphenyls and organochlorine pesticides from soil and air into radishes (Raphanus sativus)

Energy Technology Data Exchange (ETDEWEB)

Mikes, Ondrej; Cupr, Pavel [RECETOX, Research Centre for Environmental Chemistry and Ecotoxicology, Masaryk University, Kamenice 126/3, 625 00 Brno (Czech Republic); Trapp, Stefan [Department of Environmental Engineering, Technical University of Denmark, Miljoevej 113, DK-2800 Kgs. Lyngby (Denmark); Klanova, Jana [RECETOX, Research Centre for Environmental Chemistry and Ecotoxicology, Masaryk University, Kamenice 126/3, 625 00 Brno (Czech Republic)], E-mail: klanova@recetox.muni.cz

2009-02-15

Uptake of organochlorine pesticides and polychlorinated biphenyls from soil and air into radishes was measured at a heavily contaminated field site. The highest contaminant concentrations were found for DDT and its metabolites, and for {beta}-hexachlorocyclohexane. Bioconcentration factor (BCF, defined as a ratio between the contaminant concentration in the plant tissue and concentration in soil) was determined for roots, edible bulbs and shoots. Root BCF values were constant and not correlated to log K{sub OW}. A negative correlation between BCF and log K{sub OW} was found for edible bulbs. Shoot BCF values were rather constant and varied between 0.01 and 0.22. Resuspended soil particles may facilitate the transport of chemicals from soil to shoots. Elevated POP concentrations found in shoots of radishes grown in the control plot support the hypothesis that the uptake from air was more significant for shoots than the one from soil. The uptake of POPs from air was within the range of theoretical values predicted from log K{sub OA}. - Uptake from air represented for majority of persistent organochlorines a dominant pathway into shoots while uptake from soil was dominant for roots.

Gastrointestinal uptake of cadmium and zinc by a marine teleost Acanthopagrus schlegeli

International Nuclear Information System (INIS)

Zhang Li; Wang Wenxiong

2007-01-01

Gastrointestinal metal uptake represents a potential route for metal bioaccumulation in marine fish. Drinking of seawater for osmoregulation causes constant waterborne exposure of the gastrointestinal tract. Tissue specific Cd and Zn accumulation and distribution were investigated in juvenile black sea bream (Acanthopagrus schlegeli) exposed to waterborne Cd (5.7 nM) and Zn (2.6 nM) for 4 h-7 days. The intestine accumulated a large portion of the Cd (43-58%) and Zn (18-28%), and had the highest Cd (>1.0 nmol g -1 ) and Zn (>1.8 nmol g -1 ) concentrations of all body fractions, suggesting that the intestines were the major uptake sites for these waterborne metals. Among all the segments of the gastrointestinal tract, the anterior intestine played the most important role in Cd and Zn uptake. A gastrointestinal injection assay was conducted to distinguish waterborne metal uptake by the intestines and the gills. The intestine contained over 90% of the Cd in the body after depuration for 3-7 days, suggesting that little waterborne Cd entered the rest of the body through the intestine, and that Cd may exert its toxic effects on the gastrointestinal system. In contrast, intestine retained less than 20% of the total Zn after depuration, suggesting that Zn tended to be transported from the intestine to the internal tissues via the cardiovascular system. The uptake kinetics of waterborne Cd and Zn by the intestines and the gills were determined as a first-order and saturated pattern, respectively, over a wide range of ambient metal concentrations (6.2 nM-4.5 μM for Cd, and 13 nM-15 μM for Zn). An in vitro intestinal perfusion assay investigated the effects of intestinal metal composition and drinking rate on uptake. The presence of EDTA significantly reduced intestinal Zn uptake to 11%, while cysteine improved it by 59%. The intestinal Cd and Zn uptake rates were unaffected by the perfusion rate

Effects of cocaine on [11C]norepinephrine and [11C]β-CIT uptake in the primate peripheral organs measured by PET

International Nuclear Information System (INIS)

Suhara, Tetsuya; Farde, L.; Halldin, C.; Karlsson, P.; Nagren, K.

1996-01-01

The toxic properties of cocaine are related to both the central and peripheral effects. To identify possible lethal mechanisms and the accumulation of cocaine in various organs, the effects of cocaine on [ 11 C] norepinephrine and cocaine congener [ 11 C]β-CIT uptake in Cynomolgus monkeys were measured by positron emission tomography (PET). Cocaine (5 mg/kg) noticeably inhibited [ 11 C] norepinephrine uptake in the heart. The uptake of [ 11 C]β-CIT in the heart and lung was reduced by pretreatment with cocaine. There was a significant uptake in the liver which was increased following cocaine pretreatment. The results of this study confirm that cocaine blocks the neuronal uptake of norepinephrine in sympathetic nerve terminals in the myocardium. The effect of cocaine on [ 11 C]β-CIT uptake indicates that the binding sites in the heart and lung are saturable, while the uptake mechanism in the liver is different from those of the heart and lung. (author)

Acute silver toxicity in aquatic animals is a function of sodium uptake rate

DEFF Research Database (Denmark)

Bianchini, A.; Grosell, Martin Hautopp; Gregory, S.

2002-01-01

-specific surface area of the gills depends on animal body mass; and (iv) the gill surface is also the major site of Na+ loss by diffusion, we hypothesized that whole body Na+ uptake rate (i.e., turnover rate) and secondarily body mass would be good predictors of acute silver toxicity. Results obtained from...... toxicological (LC50 of AgNO3) and physiological (22Na uptake rate) tests performed on juvenile fish (rainbow trout, Oncorhynchus mykiss), early juvenile and adult crayfish (Cambarus diogenes diogenes), and neonate and adult daphnids (Daphnia magna) in moderately hard water of constant quality support the above...... hypothesis. Therefore, sensitivity to AgNO3, in terms of either total measured silver or free Ag+, was reliably predicted from the whole body Na+ uptake rate in animals with body mass ranging over 6 orders of magnitude (from micrograms to grams). A positive log-log correlation between acute AgNO3 toxicity...

Is the effect of silicon on rice uptake of arsenate (AsV) related to internal silicon concentrations, iron plaque and phosphate nutrition?

International Nuclear Information System (INIS)

Guo, W.; Zhu, Y.-G.; Liu, W.-J.; Liang, Y.-C.; Geng, C.-N.; Wang, S.-G.

2007-01-01

Solution culture experiments were conducted to investigate the effects of silicon (Si) on arsenate (As V ) uptake by rice. The addition of Si to the pretreatment or uptake solution significantly decreased shoot and root As concentrations (P < 0.001 and P < 0.05). The presence of Si in the pretreatment or uptake solution also significantly decreased shoot P concentrations (P < 0.001). The data demonstrated that both internal and external Si inhibited the uptake of As and P. Results of As uptake kinetics showed that the mechanism of the effect of Si on arsenate uptake is not caused by direct competition for active sites of transporters with As. The effect of Si on As uptake was not entirely mediated through the effect of Si on P uptake. Although the addition of Si to pretreatment solutions still significantly decreased shoot and root As concentrations, the extent of reduction became smaller when rice roots were coated with iron plaque. - Arsenate uptake by rice seedlings is affected by both Si (internal and external) and iron plaque on root surface

Localised uptake and extraction of calcium45 in dinoflagellate nuclei

International Nuclear Information System (INIS)

Sigee, D.C.

1983-01-01

The uptake of Ca 45 into cells of the dinoflagellate Glenodinium foliaceum was investigated using insoluble compound light microscope autoradiography. The distribution of silver grains showed marked localisation to the dinocaryotic nucleus, with a random scatter of grains over the surrounding protoplasm (cytoplasm and supernumerary nucleus). Correction of grain counts for lateral sensitisation from the dinocaryotic nucleus indicated an isotope concentration 16 32 times greater in this organelle compared to the rest of the cell. Cells labelled for varying periods of time showed differences in the pattern of Ca 45 uptake throughout the sample populations, but no increase in the mean level of uptake per cell. This would suggest a rapid incorporation of isotope within 1-2 hours, with little subsequent uptake. The presence of high levels of label after processing with both additive (glutaraldehyde, paraformaldehyde) and coagulative (acetic alcohol) fixatives indicated that the retention of Ca 45 in these preparations was not simply a fixation artefact. Although the isotope did not appear to be suitable for (high resolution) electron microscope autoradiography, the intranuclear site of incorporation was demonstrated indirectly using a buffer extraction technique. Prolonged treatment with phosphate buffer resulted in a large scale loss of label from both cytoplasm and dinocaryotic nucleus. The latter appeared to show specific correlation with the loss of (protein) matrix from the chromosomes - as observed under both light and electron microscopy, with no apparent change in either nucleolus or nucleoplasm. This would suggest that incorporated Ca 45 in the nucleus was largely confined to the condensed chromatin, where it was combined with the acidic proteins which make up the bulk of the chromatin matrix. The results obtained in this investigation are related to previous studies involving X-ray microanalysis and uptake of Ni 63 . (Author)

Thyroid Scan and Uptake

Medline Plus

Full Text Available ... for a thyroid scan is 30 minutes or less. Thyroid Uptake You will be given radioactive iodine ( ... for each thyroid uptake is five minutes or less. top of page What will I experience during ...

Thyroid Scan and Uptake

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Full Text Available ... Scan and Uptake Thyroid scan and uptake uses small amounts of radioactive materials called radiotracers, a special ... is a branch of medical imaging that uses small amounts of radioactive material to diagnose and determine ...

Thyroid Scan and Uptake

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Full Text Available ... uptake measurements are obtained at different times. For example, you may have uptake measurements at four to ... medicine procedures can be time consuming. It can take several hours to days for the radiotracer to ...

Thyroid Scan and Uptake

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Full Text Available ... known as a thyroid uptake. It is a measurement of thyroid function, but does not involve imaging. ... eating can affect the accuracy of the uptake measurement. Jewelry and other metallic accessories should be left ...

Thyroid Scan and Uptake

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Full Text Available ... Uptake? A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) ... of thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that ...

Endocytosis of the major yolk proteins of the silkmoth, Hyalophora cecropia: Uptake kinetics and interactions

International Nuclear Information System (INIS)

Kulakosky, P.C.

1989-01-01

The oocytes of Lepidopteran insects take up several yolk proteins in defined proportions even though their relative availability in the hemolymph changes during the several days required to complete yolk formation in all the eggs. There are three hemolymph yolk precursors, vitellogenin, microvitellogenin and lipophorin; one precursor, paravitellogenin is produced in the ovary. The control mechanism for their proportional endocytosis is not known. In this thesis, the author describe the purification of all four proteins and the radiolabeling of the hemolymph precursors. The radiolabeled proteins were tested with an in vitro incubation system to assess the biological activity of the proteins and the reliability of the incubation methods. All of the labeled probes were transferred from the incubation medium to yolk spheres within the oocyte in a saturable, energy-dependent, and stage-specific manner. The rates of uptake were similar to the estimated rates of uptake in situ. The concentration dependence of in vitro uptake was investigated and found to be consistent with in situ concentrations and the composition of yolk in mature eggs. Two precursors, vitellogenin and lipophorin, competed for uptake indicating that they share a common binding site while the third, microvitellin, did not compete with the others. Though vitellogenin and lipophorin competed for uptake, only vitellogenin displayed the unique ability to increase the uptake rate of microvitellin and fluid in vitro

Thyroid Scan and Uptake

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Full Text Available ... radioactive iodine uptake test (RAIU) is also known as a thyroid uptake. It is a measurement of ... potential to identify disease in its earliest stages as well as a patient’s immediate response to therapeutic ...

Heavy and toxic metal uptake by mesoporous hypercrosslinked SMA beads: Isotherms and kinetics

Directory of Open Access Journals (Sweden)

Renuka Gonte

2016-09-01

Full Text Available Hypercrosslinked styrene-maleic acid copolymer beads were used for the removal of metal ions from mimicked industrial effluents. The polymer was characterized by SEM which revealed the presence of a porous network. Carboxyl acid groups of the polymer were identified as active sites for metal uptake. Highly porous surface enhanced metal ion uptake was achieved through a physicochemical process. Equilibrium sorption of metal ions was best described by the Freundlich and Temkin model with R2 > 0.99. Adsorption followed pseudo first and pseudo second order reaction kinetics. Intraparticle diffusion model suggested a three step equilibrium. Desorption was a fast process with ∼90% in 60 min.

Does Elevated CO2 Alter Silica Uptake in Trees?

Directory of Open Access Journals (Sweden)

Robinson W. Fulweiler

2015-01-01

Full Text Available Human activities have greatly altered global carbon (C and N (N cycling. In fact, atmospheric concentrations of carbon dioxide (CO2 have increased 40% over the last century and the amount of N cycling in the biosphere has more than doubled. In an effort to understand how plants will respond to continued global carbon dioxide fertilization, long-term free-air CO2 enrichment (FACE experiments have been conducted at sites around the globe. Here we examine how atmospheric CO2 enrichment and N fertilization affects the uptake of silicon (Si in the Duke Forest, North Carolina, a stand dominated by Pinus taeda (loblolly pine, and five hardwood species. Specifically, we measured foliar biogenic silica (BSi concentrations in five deciduous and one coniferous species across three treatments: CO2 enrichment, N enrichment, and N and CO2 enrichment. We found no consistent trends in foliar Si concentration under elevated CO2, N fertilization, or combined elevated CO2 and N fertilization. However, two-thirds of the tree species studied here have Si foliar concentrations greater than well-known Si accumulators, such as grasses. Based on net primary production values and aboveground Si concentrations in these trees, we calculated forest Si uptake rates under control and elevated CO2 concentrations. Due largely to increased primary production, elevated CO2 enhanced the magnitude of Si uptake between 20% and 26%, likely intensifying the terrestrial silica pump. This uptake of Si by forests has important implications for Si export from terrestrial systems, with the potential to impact C sequestration and higher trophic levels in downstream ecosystems.

CaMKII regulates contraction- but not insulin-induced glucose uptake in mouse skeletal muscle.

Science.gov (United States)

Witczak, Carol A; Jessen, Niels; Warro, Daniel M; Toyoda, Taro; Fujii, Nobuharu; Anderson, Mark E; Hirshman, Michael F; Goodyear, Laurie J

2010-06-01

Studies using chemical inhibitors have suggested that the Ca(2+)-sensitive serine/threonine kinase Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is a key regulator of both insulin- and contraction-stimulated glucose uptake in skeletal muscle. However, due to nonspecificity of these inhibitors, the specific role that CaMKII may play in the regulation of glucose uptake is not known. We sought to determine whether specific inhibition of CaMKII impairs insulin- and/or contraction-induced glucose uptake in mouse skeletal muscle. Expression vectors containing green fluorescent protein conjugated to a CaMKII inhibitory (KKALHRQEAVDCL) or control (KKALHAQERVDCL) peptide were transfected into tibialis anterior muscles by in vivo electroporation. After 1 wk, muscles were assessed for peptide expression, CaMK activity, insulin- and contraction-induced 2-[(3)H]deoxyglucose uptake, glycogen concentrations, and changes in intracellular signaling proteins. Expression of the CaMKII inhibitory peptide decreased muscle CaMK activity approximately 35% compared with control peptide. Insulin-induced glucose uptake was not changed in muscles expressing the inhibitory peptide. In contrast, expression of the inhibitory peptide significantly decreased contraction-induced muscle glucose uptake (approximately 30%). Contraction-induced decreases in muscle glycogen were not altered by the inhibitory peptide. The CaMKII inhibitory peptide did not alter expression of the glucose transporter GLUT4 and did not impair contraction-induced increases in the phosphorylation of AMP-activated protein kinase (Thr(172)) or TBC1D1/TBC1D4 on phospho-Akt substrate sites. These results demonstrate that CaMKII does not regulate insulin-stimulated glucose uptake in skeletal muscle. However, CaMKII plays a critical role in the regulation of contraction-induced glucose uptake in mouse skeletal muscle.

Uptake of strontium by chamisa (Chrysothamnus nauseosus) shrub plants growing over a former liquid waste disposal site at Los Alamos National Laboratory

International Nuclear Information System (INIS)

Fresquez, P.R.; Foxx, T.S.; Naranjo, L. Jr.

1996-01-01

A major concern of managers at low-level waste burial site facilities is that plant roots may translocate contaminants up to the soil surface. This study investigates the uptake of strontium ( 90 Sr), a biologically mobile element, by chamisa (Chrysothamnus nauseosus), a deep-rooted shrub plant, growing in a former liquid waste disposal site (Solid Waste Management Unit [SWMU] 10-003[c]) at Los Alamos National Laboratory (LANL), Los Alamos, New Mexico. Surface soil samples were also collected from below (understory) and between (interspace) shrub canopies. Both chamisa plants growing over SWMU 10-003(c) contained significantly higher concentrations of 90 Sr than a control plant--one plant, in particular, contained 3.35 x 10 6 Bq kg -1 ash (9.05 x 10 4 pCi g -1 ash) in top-growth material. Similarly, soil surface samples collected underneath and between plants contained 90 Sr concentrations above background and LANL screening action levels (> 218 Bq kg -1 dry [5.90 pCi g -1 dry]); this probably occurred as a result of chamisa plant leaf fall contaminating the soil understory area followed by water and/or winds moving 90 Sr to the soil interspace areas. Although some soil surface migration of 90 Sr from SWMU 10-003(c) has occurred, the level of 90 Sr in sediments collected downstream of SWMU 10-003(c) at the LANL boundary was still within regional (background) concentrations

Root Fungal Endophytes Enhance Heavy-Metal Stress Tolerance of Clethra barbinervis Growing Naturally at Mining Sites via Growth Enhancement, Promotion of Nutrient Uptake and Decrease of Heavy-Metal Concentration.

Directory of Open Access Journals (Sweden)

Keiko Yamaji

Full Text Available Clethra barbinervis Sieb. et Zucc. is a tree species that grows naturally at several mine sites and seems to be tolerant of high concentrations of heavy metals, such as Cu, Zn, and Pb. The purpose of this study is to clarify the mechanism(s underlying this species' ability to tolerate the sites' severe heavy-metal pollution by considering C. barbinervis interaction with root fungal endophytes. We measured the heavy metal concentrations of root-zone soil, leaves, branches, and fine roots collected from mature C. barbinervis at Hitachi mine. We isolated fungal endophytes from surface-sterilized root segments, and we examined the growth, and heavy metal and nutrient absorption of C. barbinervis seedlings growing in sterilized mine soil with or without root fungal endophytes. Field analyses showed that C. barbinervis contained considerably high amounts of Cu, Zn, and Pb in fine roots and Zn in leaves. The fungi, Phialocephala fortinii, Rhizodermea veluwensis, and Rhizoscyphus sp. were frequently isolated as dominant fungal endophyte species. Inoculation of these root fungal endophytes to C. barbinervis seedlings growing in sterilized mine soil indicated that these fungi significantly enhanced the growth of C. barbinervis seedlings, increased K uptake in shoots and reduced the concentrations of Cu, Ni, Zn, Cd, and Pb in roots. Without root fungal endophytes, C. barbinervis could hardly grow under the heavy-metal contaminated condition, showing chlorosis, a symptom of heavy-metal toxicity. Our results indicate that the tree C. barbinervis can tolerate high heavy-metal concentrations due to the support of root fungal endophytes including P. fortinii, R. veluwensis, and Rhizoscyphus sp. via growth enhancement, K uptake promotion and decrease of heavy metal concentrations.

Normal cerebral FDG uptake during childhood

International Nuclear Information System (INIS)

London, Kevin; Howman-Giles, Robert

2014-01-01

Current understanding of cerebral FDG uptake during childhood originates from a small number of studies in patients with neurological abnormalities. Our aim was to describe cerebral FDG uptake in a dataset of FDG PET scans in children more likely to represent a normal population. We reviewed cerebral FDG PET scans in children up to 16 years of age with suspected/proven extracranial malignancies and the following exclusions: central nervous system metastases, previous malignancies, previous chemotherapy or radiotherapy, development of cerebral metastases during therapy, neurological conditions, taking antiepileptic medication or medications likely to interfere with cerebral metabolism, and general anaesthesia within 24 h. White matter, basal ganglia, thalamus and the cerebellar cortex were analysed using regional SUV max , and the cerebral cortex, basal ganglia, thalamus and cerebellum were analysed using a regional relative uptake analysis in comparison to maximal cortical uptake. Scans from 30 patients (age range 11 months to 16 years, mean age 10 years 5 months) were included. All regions showed increasing SUV max with age. The parietal, occipital, lateral temporal and medial temporal lobes showed lower rates of increasing FDG uptake causing changing patterns of regional FDG uptake during childhood. The cortical regions showing the most intense uptake in early childhood were the parietal and occipital lobes. At approximately 7 years of age these regions had relatively less uptake than the frontal lobes and at approximately 10 years of age these regions had relatively less uptake than the thalamus. Relative FDG uptake in the brain has not reached an adult pattern by 1 year of age, but continues to change up to 16 years of age. The changing pattern is due to different regional rates of increasing cortical FDG uptake, which is less rapid in the parietal, occipital and temporal lobes than in the frontal lobes. (orig.)

Normal cerebral FDG uptake during childhood

Energy Technology Data Exchange (ETDEWEB)

London, Kevin [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Discipline of Paediatrics and Child Health, Sydney Medical School, Sydney, NSW (Australia); Howman-Giles, Robert [The Children' s Hospital at Westmead, Department of Nuclear Medicine, Sydney, NSW (Australia); University of Sydney, Disciplines of Imaging and Paediatrics and Child Health, Sydney Medical School, Sydney, NSW (Australia)

2014-04-15

Current understanding of cerebral FDG uptake during childhood originates from a small number of studies in patients with neurological abnormalities. Our aim was to describe cerebral FDG uptake in a dataset of FDG PET scans in children more likely to represent a normal population. We reviewed cerebral FDG PET scans in children up to 16 years of age with suspected/proven extracranial malignancies and the following exclusions: central nervous system metastases, previous malignancies, previous chemotherapy or radiotherapy, development of cerebral metastases during therapy, neurological conditions, taking antiepileptic medication or medications likely to interfere with cerebral metabolism, and general anaesthesia within 24 h. White matter, basal ganglia, thalamus and the cerebellar cortex were analysed using regional SUV{sub max}, and the cerebral cortex, basal ganglia, thalamus and cerebellum were analysed using a regional relative uptake analysis in comparison to maximal cortical uptake. Scans from 30 patients (age range 11 months to 16 years, mean age 10 years 5 months) were included. All regions showed increasing SUV{sub max} with age. The parietal, occipital, lateral temporal and medial temporal lobes showed lower rates of increasing FDG uptake causing changing patterns of regional FDG uptake during childhood. The cortical regions showing the most intense uptake in early childhood were the parietal and occipital lobes. At approximately 7 years of age these regions had relatively less uptake than the frontal lobes and at approximately 10 years of age these regions had relatively less uptake than the thalamus. Relative FDG uptake in the brain has not reached an adult pattern by 1 year of age, but continues to change up to 16 years of age. The changing pattern is due to different regional rates of increasing cortical FDG uptake, which is less rapid in the parietal, occipital and temporal lobes than in the frontal lobes. (orig.)

Increased muscle glucose uptake during contractions

DEFF Research Database (Denmark)

Ploug, Thorkil; Galbo, Henrik; Richter, Erik

1984-01-01

We reinvestigated the prevailing concept that muscle contractions only elicit increased muscle glucose uptake in the presence of a so-called "permissive" concentration of insulin (Berger et al., Biochem. J. 146: 231-238, 1975; Vranic and Berger, Diabetes 28: 147-163, 1979). Hindquarters from rats...... in severe ketoacidosis were perfused with a perfusate containing insulin antiserum. After 60 min perfusion, electrical stimulation increased glucose uptake of the contracting muscles fivefold. Also, subsequent contractions increased glucose uptake in hindquarters from nondiabetic rats perfused for 1.5 h......-methylglucose uptake increased during contractions and glucose uptake was negative at rest and zero during contractions. An increase in muscle transport and uptake of glucose during contractions does not require the presence of insulin. Furthermore, glucose transport in contracting muscle may only increase if glycogen...

Thyroid Scan and Uptake

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Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is also known as a thyroid uptake. ...

Uptake of vapor and particulate polycyclic aromatic hydrocarbons by cabbage

International Nuclear Information System (INIS)

Tao, S.; Jiao, X.C.; Chen, S.H.; Xu, F.L.; Li, Y.J.; Liu, F.Z.

2006-01-01

Polycyclic aromatic hydrocarbons (PAHs) in cabbage (aerial part), air (gas and particles) and soil samples collected from two sites in Tianjin, China were measured. Although the levels of PAHs in all samples from the heavily contaminated site B were higher than those from the less contaminated site A, the PAH profiles were similar, suggesting the similarity in source type. PAH concentrations in cabbages were positively correlated to either gas or particle-bound PAHs in air. A multivariate linear regression with cabbage PAH as a function of both gas and particle-bound PAHs in air was established to quantitatively characterize the relationship between them. Inclusion of soil PAH concentrations would not improve the model, indicating that the contribution of soil PAHs to cabbage (aerial part) accumulation was insignificant. - A multivariate linear regression model was developed for predicting vegetable uptake of PAHs based on both gas and particle phases PAH concentrations

Cesium and potassium uptake by plants from soils

International Nuclear Information System (INIS)

Schaller, G.; Leising, C.; Krestel, R.; Wirth, E.

1990-11-01

The aim of the investigation was the reliable estimation of the Cs-137 root uptake by agricultural crops using the 'observed ratio model' (OR model) for the determination of transfer factors: Cs (plant)/K (plant) = OR x Cs (soil)/K (soil). For model validation representative soil (arable land, grass land, organic substrates from forests and peat) and plant samples from Bavaria were taken. These 4 parameters varied within a sufficiently wide range. In addition some samples from forest sites were taken. Soil and plant samples were taken at the same locations within 1 m 2 . (orig./HP) [de

Duloxetine and 8-OH-DPAT, but not fluoxetine, reduce depression-like behaviour in an animal model of chronic neuropathic pain.

Science.gov (United States)

Hu, Bing; Doods, Henri; Treede, Rolf-Detlef; Ceci, Angelo

2016-04-21

The current study assessed whether antidepressant and/or antinociceptive drugs, duloxetine, fluoxetine as well as (±)-8-hydroxy-2-[di-n-propylamino] tetralin (8-OH-DPAT), are able to reverse depression-like behaviour in animals with chronic neuropathic pain. Chronic constriction injury (CCI) of the sciatic nerve in rats was selected as neuropathic pain model. Mechanical hypersensitivity and depression-like behaviour were evaluated 4 weeks after surgery by "electronic algometer" and forced swimming test (FST), which measured the time of immobility, and active behaviours climbing and swimming. The selective noradrenergic and serotonergic uptake blocker duloxetine (20mg/kg) and the selective 5-HT1A agonist 8-OH-DPAT (0.5mg/kg) significantly reversed both mechanical hypersensitivity and depression-like behaviour in CCI animals. Duloxetine significantly reversed depression-like behaviour in CCI rats by increasing the time of climbing and swimming, while 8-OH-DPAT attenuated depression-like behaviour mainly by increasing the time of swimming. However, the selective serotonergic uptake blocker fluoxetine (20mg/kg) failed to attenuate mechanical hypersensitivity and depression-like behaviour, possibly due to confounding pro-nociceptive actions at 5-HT3 receptors. These data suggest to target noradrenergic and 5-HT1A receptors for treatment of chronic pain and its comorbidity depression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Fivefold increase of hydrogen uptake in MOF74 through linker decorations

Science.gov (United States)

Arter, C. A.; Zuluaga, S.; Harrison, D.; Welchman, E.; Thonhauser, T.

2016-10-01

We present ab initio results for linker decorations in Mg-MOF74, i.e., attaching various metals M =Li, Na, K, Sc, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Pd, Ag, and Pt near the ring of the linker, creating new strong adsorption sites and thus maximizing small-molecule uptake. We find that in most cases these decorations influence the overall form and structure of Mg-MOF74 only marginally. After the initial screening, we chose metals that bind favorably to the linker and further investigated adsorption of H2,CO2, and H2O for M =Li , Na, K, and Sc. For the case of H2 we show that up to 24 additional guest molecules can be adsorbed in the metal-organic framework (MOF) unit cell, with binding energies comparable to the original open-metal sites at the six corners of the channel. This leads to a fivefold increase of the molecule uptake in Mg-MOF74, with tremendous impact on many applications in general and hydrogen storage in particular, where the gravimetric hydrogen density increases from 1.63 to 7.28 mass % and the volumetric density increases from 15.10 to 75.50 g H2L-1 .

Nitrogen uptake and assimilation by corn roots

International Nuclear Information System (INIS)

Yoneyama, Tadakatsu; Akiyama, Yoko; Kumazawa, Kikuo

1977-01-01

The site of nitrogen uptake in the apical root zone of corn was experimentally investigated. Two experiments were performed. The one is to see the assimilation of nitrate and ammonium and the effects of low temperature on it. The 4-day-old roots were treated with 15 N-labelled inorganic nitrogen of 20 ppm N in 5 x 10 -4 M CaSO 4 solution at 30 deg. C and 0 deg. C. The other is to see the nitrogen uptake at apical root zone and the utilization of newly absorbed nitrogen at the root top. The 4-day-old roots were transferred into 5 x 10 -4 M CaSO 4 solution containing 15 N-labelled ammonium nitrate of 40 ppm N. As a result, the effect of low temperature on the nitrogen uptake appeared to be more drastic in the case of nitrate than ammonium. The 15 N content of amino acids indicates that ammonium is assimilated into amino acids even at 0 deg. C, but nitrate is not. The ammonium nitrogen seemed to be absorbed at both cell dividing and elongating zones. On the other hand, nitrate nitrogen seemed to be strongly absorbed at cell elongating zone. The nitrogen in the apical part may be supplied not only by direct absorption but also by translocation from the basal part. The clear difference was found in the utilization of nitrate and ammonium nitrogen at the root top when the root was elongating. This may be due to the difference of assimilation products of inorganic nitrogen. Newly absorbed ammonium nitrogen is more utilizable for the growth of root top than nitrate nitrogen. (Iwakiri, K.)

Adsorption uptake of synthetic organic chemicals by carbon nanotubes and activated carbons

Science.gov (United States)

Brooks, A. J.; Lim, Hyung-nam; Kilduff, James E.

2012-07-01

Carbon nanotubes (CNTs) have shown great promise as high performance materials for adsorbing priority pollutants from water and wastewater. This study compared uptake of two contaminants of interest in drinking water treatment (atrazine and trichloroethylene) by nine different types of carbonaceous adsorbents: three different types of single walled carbon nanotubes (SWNTs), three different sized multi-walled nanotubes (MWNTs), two granular activated carbons (GACs) and a powdered activated carbon (PAC). On a mass basis, the activated carbons exhibited the highest uptake, followed by SWNTs and MWNTs. However, metallic impurities in SWNTs and multiple walls in MWNTs contribute to adsorbent mass but do not contribute commensurate adsorption sites. Therefore, when uptake was normalized by purity (carbon content) and surface area (instead of mass), the isotherms collapsed and much of the CNT data was comparable to the activated carbons, indicating that these two characteristics drive much of the observed differences between activated carbons and CNT materials. For the limited data set here, the Raman D:G ratio as a measure of disordered non-nanotube graphitic components was not a good predictor of adsorption from solution. Uptake of atrazine by MWNTs having a range of lengths and diameters was comparable and their Freundlich isotherms were statistically similar, and we found no impact of solution pH on the adsorption of either atrazine or trichloroethylene in the range of naturally occurring surface water (pH = 5.7-8.3). Experiments were performed using a suite of model aromatic compounds having a range of π-electron energy to investigate the role of π-π electron donor-acceptor interactions on organic compound uptake by SWNTs. For the compounds studied, hydrophobic interactions were the dominant mechanism in the uptake by both SWNTs and activated carbon. However, comparing the uptake of naphthalene and phenanthrene by activated carbon and SWNTs, size exclusion effects

Adsorption uptake of synthetic organic chemicals by carbon nanotubes and activated carbons

International Nuclear Information System (INIS)

Brooks, A J; Kilduff, James E; Lim, Hyung-nam

2012-01-01

Carbon nanotubes (CNTs) have shown great promise as high performance materials for adsorbing priority pollutants from water and wastewater. This study compared uptake of two contaminants of interest in drinking water treatment (atrazine and trichloroethylene) by nine different types of carbonaceous adsorbents: three different types of single walled carbon nanotubes (SWNTs), three different sized multi-walled nanotubes (MWNTs), two granular activated carbons (GACs) and a powdered activated carbon (PAC). On a mass basis, the activated carbons exhibited the highest uptake, followed by SWNTs and MWNTs. However, metallic impurities in SWNTs and multiple walls in MWNTs contribute to adsorbent mass but do not contribute commensurate adsorption sites. Therefore, when uptake was normalized by purity (carbon content) and surface area (instead of mass), the isotherms collapsed and much of the CNT data was comparable to the activated carbons, indicating that these two characteristics drive much of the observed differences between activated carbons and CNT materials. For the limited data set here, the Raman D:G ratio as a measure of disordered non-nanotube graphitic components was not a good predictor of adsorption from solution. Uptake of atrazine by MWNTs having a range of lengths and diameters was comparable and their Freundlich isotherms were statistically similar, and we found no impact of solution pH on the adsorption of either atrazine or trichloroethylene in the range of naturally occurring surface water (pH = 5.7–8.3). Experiments were performed using a suite of model aromatic compounds having a range of π-electron energy to investigate the role of π–π electron donor–acceptor interactions on organic compound uptake by SWNTs. For the compounds studied, hydrophobic interactions were the dominant mechanism in the uptake by both SWNTs and activated carbon. However, comparing the uptake of naphthalene and phenanthrene by activated carbon and SWNTs, size exclusion

Root uptake of transuranic elements

International Nuclear Information System (INIS)

Schulz, R.K.

1977-01-01

The uptake of elements by plant roots is one of the important pathways of entry of many elements into the food chain of man. Data are cited showing plutonium concentration ratios, plant/soil, ranging from 10 -10 to 10 -3 . Concentration ratios for americium range from 10 -7 to 10 +1 . Limited experiments with curium and neptunium indicate that root uptake of curium is similar to that of americium and that plant uptake of neptunium is substantially larger than that of curium and americium. The extreme ranges of concentration ratios cited for plutonium and americium are due to a number of causes. Experimental conditions such as very intensive cropping will lead to abnormally high concentration ratios. In some experiments, addition of chelating agents markedly increased plant root uptake of transuranic elements. Particle size and composition of the source material influenced uptake of the transuranics by plants. Translocation within the plant, and soil factors such as pH and organic matter content, all affect concentration ratios

Paediatric and adolescent Hodgkin lymphoma: information derived from diffuse organ uptake of 18 F-fluorodeoxyglucose on pre-treatment and on interim PET/CT

Energy Technology Data Exchange (ETDEWEB)

Jorgov, Linda [AP-HP and Universite Pierre et Marie Curie, Department of Nuclear Medicine, Hopital Tenon, Paris (France); Semmelweis University, Department of Nuclear Medicine, Budapest (Hungary); Montravers, Francoise; Talbot, Jean-Noel [AP-HP and Universite Pierre et Marie Curie, Department of Nuclear Medicine, Hopital Tenon, Paris (France); Balogova, Sona [AP-HP and Universite Pierre et Marie Curie, Department of Nuclear Medicine, Hopital Tenon, Paris (France); Comenius University and St. Elisabeth Oncology Institute, Department of Nuclear Medicine, Bratislava (Slovakia); Ragu, Christine; Landman-Parker, Judith [Hopital Trousseau AP-HP and Universite Pierre et Marie Curie, Department of Paediatric Haematology and Oncology, Paris (France); Pacquement, Helene [Institut Curie, Department of Paediatric Oncology, Paris (France); Leblanc, Thierry [Hopital Robert Debre, AP-HP, Department of Paediatric Haematology, Paris (France); Abbou, Samuel [Institut Gustave Roussy, Department of Children and Adolescent Cancer, Villejuif (France); Ducou-Lepointe, Hubert [AP-HP and Universite Pierre et Marie Curie, Department of Radiology, Hopital Trousseau, Paris (France)

2016-07-15

To evaluate, in children with Hodgkin lymphoma (HL), the frequency and intensity of visually diffuse FDG uptake by selected organs at baseline (bPET) and on interim PET/CT (iPET), and to evaluate the relation between FDG uptake, metabolic response and evolution of the disease with treatment. Thirty children with HL had bPET and then iPET after two cycles of treatment, which were blind-read retrospectively. Excluding sites with focal uptake, diffuse FDG uptake by thymus, bone marrow at iliac crests, liver, spleen, and the spinal cord at the 12th thoracic vertebra (Th12) was evaluated visually using a three-point scoring method and semiquantitatively by measuring SUVmax. Visualisation of activated brown adipose tissue (BAT) was also quoted. Five children had refractory HL. Recurrence-free survival was determined for each patient. Nine patients relapsed; in 21 non-relapsing patients, the median follow-up period was 43 months (range: 28-61). On bPET, the rate of diffuse and intense (visual score = 3) FDG uptake was 48 % in the spleen, 43 % in the spinal cord at Th12, 37 % in bone marrow, 21 % in the thymus and 7 % in BAT. At least one of those sites showed diffuse and intense FDG uptake in 77 % of patients. On iPET, a significant decrease in SUVmax was observed in thymus, iliac crest bone marrow and spleen, but not in spinal cord. In contrast, the FDG uptake by the liver significantly increased. The absence of SUVmax increase in the liver between bPET and iPET was the best criterion to predict a refractory disease (PPV = 55 %, NPV = 100 %). Its area under ROC (AUC) was 0.9 vs. 0.73 for five-point Deauville criteria. For prediction of relapse, two criteria were derived from the evolution of diffuse uptake between bPET and iPET: no increase in liver uptake and an increase > 5 % in spinal cord uptake. As compared with 13 patients who matched none of those criteria, the hazard ratio (HR) for relapse was 2.1 in 13 patients who matched one criterion, and 10.3 in four

Paediatric and adolescent Hodgkin lymphoma: information derived from diffuse organ uptake of 18 F-fluorodeoxyglucose on pre-treatment and on interim PET/CT

International Nuclear Information System (INIS)

Jorgov, Linda; Montravers, Francoise; Talbot, Jean-Noel; Balogova, Sona; Ragu, Christine; Landman-Parker, Judith; Pacquement, Helene; Leblanc, Thierry; Abbou, Samuel; Ducou-Lepointe, Hubert

2016-01-01

To evaluate, in children with Hodgkin lymphoma (HL), the frequency and intensity of visually diffuse FDG uptake by selected organs at baseline (bPET) and on interim PET/CT (iPET), and to evaluate the relation between FDG uptake, metabolic response and evolution of the disease with treatment. Thirty children with HL had bPET and then iPET after two cycles of treatment, which were blind-read retrospectively. Excluding sites with focal uptake, diffuse FDG uptake by thymus, bone marrow at iliac crests, liver, spleen, and the spinal cord at the 12th thoracic vertebra (Th12) was evaluated visually using a three-point scoring method and semiquantitatively by measuring SUVmax. Visualisation of activated brown adipose tissue (BAT) was also quoted. Five children had refractory HL. Recurrence-free survival was determined for each patient. Nine patients relapsed; in 21 non-relapsing patients, the median follow-up period was 43 months (range: 28-61). On bPET, the rate of diffuse and intense (visual score = 3) FDG uptake was 48 % in the spleen, 43 % in the spinal cord at Th12, 37 % in bone marrow, 21 % in the thymus and 7 % in BAT. At least one of those sites showed diffuse and intense FDG uptake in 77 % of patients. On iPET, a significant decrease in SUVmax was observed in thymus, iliac crest bone marrow and spleen, but not in spinal cord. In contrast, the FDG uptake by the liver significantly increased. The absence of SUVmax increase in the liver between bPET and iPET was the best criterion to predict a refractory disease (PPV = 55 %, NPV = 100 %). Its area under ROC (AUC) was 0.9 vs. 0.73 for five-point Deauville criteria. For prediction of relapse, two criteria were derived from the evolution of diffuse uptake between bPET and iPET: no increase in liver uptake and an increase > 5 % in spinal cord uptake. As compared with 13 patients who matched none of those criteria, the hazard ratio (HR) for relapse was 2.1 in 13 patients who matched one criterion, and 10.3 in four

Uptake of Radionuclide Metals by SPME Fibers

International Nuclear Information System (INIS)

Duff, M; S Crump, S; Robert Ray, R; Keisha Martin, K; Donna Beals, D

2006-08-01

The Federal Bureau of Investigation (FBI) Laboratory currently does not have on site facilities for handling radioactive evidentiary materials and there are no established FBI methods or procedures for decontaminating high explosive (HE) and fire debris (FD) evidence while maintaining evidentiary value. One experimental method for the isolation of HE and FD residue involves using solid phase microextraction or SPME fibers to remove residue of interest. Due to their high affinity for organics, SPME fibers should have little affinity for most metals. However, no studies have measured the affinity of radionuclides for SPME fibers. The focus of this research was to examine the affinity of dissolved radionuclide ( 239/240 Pu, 238 U, 237 Np, 85 Sr, 133 Ba, 137 Cs, 60 Co and 226 Ra) and stable radionuclide surrogate metals (Sr, Co, Ir, Re, Ni, Ba, Cs, Nb, Zr, Ru, and Nd) for SPME fibers at the exposure conditions that favor the uptake of HE and FD residues. Our results from radiochemical and mass spectrometric analyses indicate these metals have little measurable affinity for these SPME fibers during conditions that are conducive to HE and FD residue uptake with subsequent analysis by liquid or gas phase chromatography with mass spectrometric detection

Characterization of cadmium uptake in Lactobacillus plantarum and isolation of cadmium and manganese uptake mutants

Energy Technology Data Exchange (ETDEWEB)

Hao, Z.; Reiske, H.R.; Wilson, D.B.

1999-11-01

Two different Cd{sup 2+} uptake systems were identified in Lactobacillus plantarum. One is a high-affinity, high-velocity Mn{sup 2+} uptake system which also takes up Cd{sup 2+} and is induced by Mn{sup 2+} starvation. The calculated K{sub m} and V{sub max} are 0.26 {mu}M and 3.6 {mu}mol g of dry cell{sup {minus}1} min{sup {minus}1}, respectively. Unlike Mn{sup 2+} uptake, which is facilitated by citrate and related tricarboxylic acids, Cd{sup 2+} uptake is weakly inhibited by citrate. Cd{sup 2+} and Mn{sup 2+} are competitive inhibitors of each other, and the affinity of the system for Cd{sup 2+} is higher than that for Mn{sup 2+}. The other Cd{sup 2+} uptake system is expressed in Mn{sup 2+}-sufficient cells, and no K{sub m} can be calculated for it because uptake is nonsaturable. Mn{sup 2+} does not compete for transport through this system, nor does any other tested cation, i.e., Zn{sup 2+}, Cu{sup 2+}, Co{sup 2+}, Mg{sup 2+}, Ca{sup 2+}, Fe{sup 2+}, or Ni{sup 2+}. Both systems require energy, since uncouplers completely inhibit their activities. Two Mn{sup 2+}-dependent L. plantarum mutants were isolated by chemical mutagenesis and ampicillin enrichment. They required more than 5,000 times as much Mn{sup 2+} for growth as the parental strain. Mn{sup 2+} starvation-induced Cd{sup 2+} uptake in both mutants was less than 5% the wild-type rate. The low level of long-term Mn{sup 2+} or Cd{sup 2+} accumulation by the mutant strains also shows that the mutations eliminate the high-affinity Mn{sup 2+} and Cd{sup 2+} uptake system.

FDG uptake in axillary lymph nodes after vaccination against pandemic (H1N1)

International Nuclear Information System (INIS)

Panagiotidis, Emmanouil; Exarhos, Demetrios; Housianakou, Irene; Bournazos, Apostolos; Datseris, Ioannis

2010-01-01

To alert the imaging community to potential false positive findings related to current immunization programmes against H1N1 influenza virus. We reviewed 10 patients referred for positron emission tomography/computed tomography (PET/CT) who had undergone recent vaccination. All studies showed 18 F-fluorodeoxyglucose (FDG) uptake in the draining axillary lymph nodes close to the vaccination site, while low-dose CT revealed lymph nodes ranged between 0.5 cm and 1.2 cm at the same site. This potential pitfall in PET/CT should be borne in mind during current vaccination programmes. (orig.)

Uptake of atmospheric tritium by market foods

International Nuclear Information System (INIS)

Inoue, Y.; Tanaka-Miyamoto, K.; Iwakura, T.

1992-01-01

In this paper uptake of tritium by market foods from tritiated water vapor in the air is investigated using cereals and beans purchased in Deep River, Canada. The concentrations of tissue free water tritium (TFWT) and organically bound tritium (OBT) range from 12 to 79% and from 10 to 38% respectively, of that estimated for atmospheric water vapor of the sampling month. The specific activity ratios of OBT to TFWT were constant for cereals, but variable for beans. The elevated OBT was shown to be the result of isotopic exchange of labile hydrogen by the fact that washing the foods with tritium free-water reduced their tritium contents to levels characteristic of their production sites

Buffer mass test - Site documentation

International Nuclear Information System (INIS)

Pusch, R.

1983-10-01

The purpose of this report is to compile test site data that are assumed to be of importance for the interpretation of the Buffer Mass Test. Since this test mainly concerns water uptake and migration processes in the integrated rock/backfill system and the development of temperature fields in this system, the work has been focused on the constitution and hydrology of the rock. The major constitutional rock feature of interest for the BMT is the frequency and distribution of joints and fractures. The development of models for water uptake into the highly compacted bentonite in the heater holes requires a very detailed fracture survey. The present investigation shows that two of the holes (no. 1 and 2) are located in richly fractured rock, while the others are located in fracture-poor to moderately fractured rock. The hydrological conditions of the rock in the BMT area are characterized by water pressures of as much as 100 m water head at a few meters distance from the test site. The average hydraulic conductivity of the rock that confines the BMT tunnel has been estimated at about 10 -10 m/s by Lawrence Laboratory. The actual distribution of the water that enters the tunnel has been estimated by observing the successive moistening after having switched off the ventilation, and this has offered basis of predicting the rate and uniformity of the water uptake in the tunnel backfill. As to the heater holes the detailed fracture patterns and various inflow measurements have yielded a similar basis. The report also gives major data on the rock temperature, gas conditions, mineralogy, rock mechanics, and groundwater chemistry for BMT purposes. (author)

Fire effects on the mobilization and uptake of nitrogen by cheatgrass (Bromus tectorum L.)

Science.gov (United States)

Brittany G. Johnson; Dale W. Johnson; Jeanne C. Chambers; Robert R. Blank

2011-01-01

Cheatgrass (Bromus tectorum L.), an invasive annual grass, is displacing native species and causing increased fire frequency in the Great Basin of the southwestern United States. Growth and nitrogen uptake patterns by cheatgrass were examined in a greenhouse study using soils from sites with the same soil type but different fire histories: 1) an area that burned in...

Accessibility and screening uptake rates for gestational diabetes mellitus in Ireland.

LENUS (Irish Health Repository)

Cullinan, John

2012-03-01

Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy and is associated with a range of maternal and neonatal complications and conditions. Given increasing levels of prevalence worldwide, there are growing calls for the implementation of screening practices to identify and treat positive GDM cases. This paper uses a unique dataset to investigate the role of healthcare centre accessibility on the decision to attend for screening, employing geographic information systems, econometric and simulation techniques. We focus on the extent to which \\'travel distance to screening hospital site\\' impacts upon the individual\\'s screen uptake decision, whether significant geographic inequalities exist in relation to accessibility to screening, and the likely impact on uptake rates of providing screening services at a local level via primary care. Our findings have important implications for the provision of GDM screening services.

Short-term serotonergic but not noradrenergic antidepressant administration reduces attentional vigilance to threat in healthy volunteers.

Science.gov (United States)

Murphy, Susannah E; Yiend, Jenny; Lester, Kathryn J; Cowen, Philip J; Harmer, Catherine J

2009-03-01

Anxiety is associated with threat-related biases in information processing such as heightened attentional vigilance to potential threat. Such biases are an important focus of psychological treatments for anxiety disorders. Selective serotonin reuptake inhibitors (SSRIs) are effective in the treatment of a range of anxiety disorders. The aim of this study was to assess the effect of an SSRI on the processing of threat in healthy volunteers. A selective noradrenergic reuptake inhibitor (SNRI), which is not generally used in the treatment of anxiety, was used as a contrast to assess the specificity of SSRI effects on threat processing. Forty-two healthy volunteers were randomly assigned to 7 d double-blind intervention with the SSRI citalopram (20 mg/d), the SNRI reboxetine (8 mg/d), or placebo. On the final day, attentional and interpretative bias to threat was assessed using the attentional probe and the homograph primed lexical decision tasks. Citalopram reduced attentional vigilance towards fearful faces but did not affect the interpretation of ambiguous homographs as threatening. Reboxetine had no significant effect on either of these measures. Citalopram reduces attentional orienting to threatening stimuli, which is potentially relevant to its clinical use in the treatment of anxiety disorders. This finding supports a growing literature suggesting that an important mechanism through which pharmacological agents may exert their effects on mood is by reversing the cognitive biases that characterize the disorders that they treat. Future studies are needed to clarify the neural mechanisms through which these effects on threat processing are mediated.

The minute virus of mice exploits different endocytic pathways for cellular uptake

International Nuclear Information System (INIS)

Garcin, Pierre O.; Panté, Nelly

2015-01-01

The minute virus of mice, prototype strain (MVMp), is a non-enveloped, single-stranded DNA virus of the family Parvoviridae. Unlike other parvoviruses, the mechanism of cellular uptake of MVMp has not been studied in detail. We analyzed MVMp endocytosis in mouse LA9 fibroblasts and a tumor cell line derived from epithelial–mesenchymal transition through polyomavirus middle T antigen transformation in transgenic mice. By a combination of immunofluorescence and electron microscopy, we found that MVMp endocytosis occurs at the leading edge of migrating cells in proximity to focal adhesion sites. By using drug inhibitors of various endocytic pathways together with immunofluorescence microscopy and flow cytometry analysis, we discovered that MVMp can use a number of endocytic pathways, depending on the host cell type. At least three different mechanisms were identified: clathrin-, caveolin-, and clathrin-independent carrier-mediated endocytosis, with the latter occurring in transformed cells but not in LA9 fibroblasts. - Highlights: • MVMp uptake takes place at the leading edge of migrating cells. • MVMp exploits a variety of endocytic pathways. • MVMp could use clathrin- and caveolin-mediated endocytosis. • MVMp could also use clathrin-independent carriers for cellular uptake

The minute virus of mice exploits different endocytic pathways for cellular uptake

Energy Technology Data Exchange (ETDEWEB)

Garcin, Pierre O.; Panté, Nelly, E-mail: pante@zoology.ubc.ca

2015-08-15

The minute virus of mice, prototype strain (MVMp), is a non-enveloped, single-stranded DNA virus of the family Parvoviridae. Unlike other parvoviruses, the mechanism of cellular uptake of MVMp has not been studied in detail. We analyzed MVMp endocytosis in mouse LA9 fibroblasts and a tumor cell line derived from epithelial–mesenchymal transition through polyomavirus middle T antigen transformation in transgenic mice. By a combination of immunofluorescence and electron microscopy, we found that MVMp endocytosis occurs at the leading edge of migrating cells in proximity to focal adhesion sites. By using drug inhibitors of various endocytic pathways together with immunofluorescence microscopy and flow cytometry analysis, we discovered that MVMp can use a number of endocytic pathways, depending on the host cell type. At least three different mechanisms were identified: clathrin-, caveolin-, and clathrin-independent carrier-mediated endocytosis, with the latter occurring in transformed cells but not in LA9 fibroblasts. - Highlights: • MVMp uptake takes place at the leading edge of migrating cells. • MVMp exploits a variety of endocytic pathways. • MVMp could use clathrin- and caveolin-mediated endocytosis. • MVMp could also use clathrin-independent carriers for cellular uptake.

Clinical significance of post-treatment {sup 18}F-fluorodeoxyglucose uptake in cervical lymph nodes in patients with diffuse large B-cell lymphoma

Energy Technology Data Exchange (ETDEWEB)

An, Young-Sil; Yoon, Joon-Kee; Lee, Su Jin [Ajou University School of Medicine, Department of Nuclear Medicine and Molecular Imaging, Woncheon-dong, Yeongtong-gu, Gyeonggi-do, Suwon-si (Korea, Republic of); Jeong, Seong Hyun; Lee, Hyun Woo [Ajou University School of Medicine, Department of Hematology-Oncology, Woncheon-dong, Yeongtong-gu, Gyeonggi-do, Suwon (Korea, Republic of)

2016-12-15

We assessed the clinical significance of FDG uptake in cervical lymph nodes after treatment of patients with DLBCL. In total, 87 patients with DLBCL were enrolled. All patients had newly appeared FDG uptake in cervical lymph nodes on PET/CT during follow-up after cessation of therapy. Cervical lymph nodes were finally diagnosed as benign or malignant according to histopathological findings or follow-up PET. Clinical characteristics and PET findings were compared between groups and factors associated with malignant lesions were evaluated. Only 8 (9.2 %) patients with cervical lymph nodes with FDG uptake ultimately had malignancy. FDG uptake lymph nodes appeared significantly earlier in the malignant group than in patients with benign FDG uptake (p = 0.013). Primary nodal lymphoma was more frequent in patients with cancer spread than in those with benign FDG uptake in lymph nodes (p < 0.001). Most cervical lymph nodes with FDG uptake (about 91 %) appearing after treatment of malignant DLBCL were ultimately benign. The elapsed time between the end of therapy and the appearance of cervical lymph nodes with FDG uptake and the primary sites of lymphomas are helpful clues in determining which cases are malignant. (orig.)

Radioiodine uptake by plants from soils

International Nuclear Information System (INIS)

Sabova, T.

1976-01-01

The uptake and accumulation of radioiodine by wheat, maize and peas from various types of soil have been studied. The uptake depends on the type of soil, on its content of organic matter and on the amount of fertilizer. Radioiodine is mainly accumulated in the roots. Accumulation in above-ground plant parts decreases in the following order: wheat, maize, peas. Uptake was highest from humus and clay soils and lowest from black and meadow soils. Application of chloride fertilizer or carrier iodine lead to an increase of radioiodine uptake in the whole plant. (author)

Uptake of mass drug administration programme for schistosomiasis control in Koome Islands, Central Uganda.

Directory of Open Access Journals (Sweden)

Doreen Tuhebwe

Full Text Available Schistosomiasis is one of the neglected tropical diseases targeted for elimination in Uganda through the Mass Drug Administration (MDA programme. Praziquantel has been distributed using community resource persons in fixed sites and house-to-house visits; however the uptake is still below target coverage. In 2011/2012 MDA exercise, uptake stood at 50% yet WHO target coverage is 75% at community level. We assessed the uptake of MDA and the associated factors in Koome Islands, Central Uganda.In March 2013, we conducted a mixed methods cross sectional study in 15 randomly selected villages. We interviewed a total of 615 respondents aged 18 years and above using semi structured questionnaires and five key informants were also purposively selected. Univariate and multivariate analysis was done. MDA uptake was defined as self reported swallowing of praziquantel during the last (2012 MDA campaign. We conducted key informant interviews with Ministry of Health, district health personnel and community health workers.Self reported uptake of praziquantel was 44.7% (275/615, 95% confidence interval (CI 40.8-48.7%. Of the 275 community members who said they had swallowed praziquantel, 142 (51.6% reported that they had developed side effects. Uptake of MDA was more likely if the respondent was knowledgeable about schistosomiasis transmission and prevention (adjusted odds ratio [AOR] 1.85, 95% CI 1.22-2.81 and reported to have received health education from the health personnel (AOR 5.95, 95% CI 3.67-9.65. Service delivery challenges such as drug shortages and community health worker attrition also influenced MDA in Koome Islands.Uptake of MDA for schistosomiasis control in Koome was sub optimal. Lack of knowledge about schistosomiasis transmission and prevention, inadequate health education and drug shortages are some of the major factors associated with low uptake. These could be addressed through routine health education and systematic drug supply for the

High affinity, ligand specific uptake of complexed copper-67 by brain tissue incubated in vitro

International Nuclear Information System (INIS)

Barnea, A.; Hartter, D.E.

1987-01-01

Copper is an essential metal that is highly concentrated in the brain. The blood, the sole source of tissue Cu, contains 16-20 μM Cu, of which >95% is complexed to proteins and 2 was 10 times greater than that of CuAlbumin or Cu(II). Within the range of 0.2-150μM Cu, multiple uptake sites for CuHis were apparent. Increasing the molar ratio of His:Cu had a differential effect on Cu uptake: enhancing uptake at [Cu] 1 μM. Thus, using a His:Cu ratio of 1000, they observed a high affinity process exhibiting saturating and half saturating values of 5 μM and 1.5 μM Cu, respectively; using a His:Cu ratio of 2, they observed a low affinity process exhibiting saturating and half-saturating values of 100 μM and 40 μM Cu, respectively. Both processes required thermic but not metabolic energy, suggestive of facilitated diffusion. Considering the blood brain barrier for proteins, CuHis appears to be the major substrate for Cu uptake by neuronal tissue. They demonstrate the existence of a ligand specific, high affinity (apparent Km about 1.5 μM Cu) uptake process for CuHis in the brain, operative at the physiological concentration range of CuHis and histidine

Pharmacological and therapeutic directions in ADHD: Specificity in the PFC

Directory of Open Access Journals (Sweden)

Levy Florence

2008-02-01

Full Text Available Abstract Background Recent directions in the treatment of ADHD have involved both a broadening of pharmacological perspectives to include nor-adrenergic as well as dopaminergic agents. A review of animal and human studies of pharmacological and therapeutic directions in ADHD suggests that the D1 receptor is a specific site for dopaminergic regulation of the PFC, but optimal levels of dopamine (DA are required for beneficial effects on working memory. Animal and human studies indicate that the alpha-2A receptor is also important for prefrontal regulation, leaving open the question of the relative importance of these receptor sites. The therapeutic effects of ADHD medications in the prefrontal cortex have focused attention on the development of working memory capacity in ADHD. Hypothesis The actions of dopaminergic vs noradrenergic agents, currently available for the treatment of ADHD have overlapping, but different actions in the prefrontal cortex (PFC and subcortical centers. While stimulants act on D1 receptors in the dorsolateral prefrontal cortex, they also have effects on D2 receptors in the corpus striatum and may also have serotonergic effects at orbitofrontal areas. At therapeutic levels, dopamine (DA stimulation (through DAT transporter inhibition decreases noise level acting on subcortical D2 receptors, while NE stimulation (through alpha-2A agonists increases signal by acting preferentially in the PFC possibly on DAD1 receptors. On the other hand, alpha-2A noradrenergic transmission is more limited to the prefrontal cortex (PFC, and thus less likely to have motor or stereotypic side effects, while alpha-2B and alpha-2C agonists may have wider cortical effects. The data suggest a possible hierarchy of specificity in the current medications used in the treatment of ADHD, with guanfacine likely to be most specific for the treatment of prefrontal attentional and working memory deficits. Stimulants may have broader effects on both vigilance

Insulin resistance and maximal oxygen uptake

DEFF Research Database (Denmark)

Seibaek, Marie; Vestergaard, Henrik; Burchardt, Hans

2003-01-01

BACKGROUND: Type 2 diabetes, coronary atherosclerosis, and physical fitness all correlate with insulin resistance, but the relative importance of each component is unknown. HYPOTHESIS: This study was undertaken to determine the relationship between insulin resistance, maximal oxygen uptake......, and the presence of either diabetes or ischemic heart disease. METHODS: The study population comprised 33 patients with and without diabetes and ischemic heart disease. Insulin resistance was measured by a hyperinsulinemic euglycemic clamp; maximal oxygen uptake was measured during a bicycle exercise test. RESULTS......: There was a strong correlation between maximal oxygen uptake and insulin-stimulated glucose uptake (r = 0.7, p = 0.001), and maximal oxygen uptake was the only factor of importance for determining insulin sensitivity in a model, which also included the presence of diabetes and ischemic heart disease. CONCLUSION...

Influence of ornithine decarboxylase antizymes and antizyme inhibitors on agmatine uptake by mammalian cells.

Science.gov (United States)

Ramos-Molina, Bruno; López-Contreras, Andrés J; Lambertos, Ana; Dardonville, Christophe; Cremades, Asunción; Peñafiel, Rafael

2015-05-01

Agmatine (4-aminobutylguanidine), a dicationic molecule at physiological pH, exerts relevant modulatory actions at many different molecular target sites in mammalian cells, having been suggested that the administration of this compound may have therapeutic interest. Several plasma membrane transporters have been implicated in agmatine uptake by mammalian cells. Here we report that in kidney-derived COS-7 cell line, at physiological agmatine levels, the general polyamine transporter participates in the plasma membrane translocation of agmatine, with an apparent Km of 44 ± 7 µM and Vmax of 17.3 ± 3.3 nmol h(-1) mg(-1) protein, but that at elevated concentrations, agmatine can be also taken up by other transport systems. In the first case, the physiological polyamines (putrescine, spermidine and spermine), several diguanidines and bis(2-aminoimidazolines) and the polyamine transport inhibitor AMXT-1501 markedly decreased agmatine uptake. In cells transfected with any of the three ornithine decarboxylase antizymes (AZ1, AZ2 and AZ3), agmatine uptake was dramatically reduced. On the contrary, transfection with antizyme inhibitors (AZIN1 and AZIN2) markedly increased the transport of agmatine. Furthermore, whereas putrescine uptake was significantly decreased in cells transfected with ornithine decarboxylase (ODC), the accumulation of agmatine was stimulated, suggesting a trans-activating effect of intracellular putrescine on agmatine uptake. All these results indicate that ODC and its regulatory proteins (antizymes and antizyme inhibitors) may influence agmatine homeostasis in mammalian tissues.

5-fold increase of hydrogen uptake in MOF74 through linker decorations

Science.gov (United States)

Thonhauser, T.; Zuluaga, S.; Harrison, D.; Welchman, E.; Arter, C.

We present ab initio results for linker decorations in Mg-MOF74-i.e. attaching various metals  = Li, Na, K, Sc, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Pd, Ag, and Pt near the ring of the linker-creating new strong adsorption sites and thus maximizing small molecule uptake. We find that in most cases these decorations influence the overall form and structure of Mg-MOF74 only marginally. After the initial screening we chose metals that bind favorably to the linker and further investigate adsorption of H2, CO2, and H2O for  = Li, Na, K, and Sc. For the case of H2 we show that up to 24 additional guest molecules can be adsorbed in the MOF unit cell, with binding energies comparable to the original open-metal sites at the six corners of the channel. This leads to a 5-fold increase of the molecule uptake in Mg-MOF74, with tremendous impact on many applications in general and hydrogen storage in particular-where the gravimetric hydrogen density increases from 1 . 63 mass% to 7 . 28 mass% and the volumetric density from 15.10 g H2 L-1 to 75.50 g H2 L-1. This work was supported by NSF Grant No. DMR-1145968.

Thyroid uptake software

International Nuclear Information System (INIS)

Alonso, Dolores; Arista, Eduardo

2003-01-01

The DETEC-PC software was developed as a complement to a measurement system (hardware) able to perform Iodine Thyroid Uptake studies. The software was designed according to the principles of Object oriented programming using C++ language. The software automatically fixes spectrometric measurement parameters and besides patient measurement also performs statistical analysis of a batch of samples. It possesses a PARADOX database with all information of measured patients and a help system with the system options and medical concepts related to the thyroid uptake study

Metal uptake by homegrown vegetables – The relative importance in human health risk assessments at contaminated sites

International Nuclear Information System (INIS)

Augustsson, Anna L.M.; Uddh-Söderberg, Terese E.; Hogmalm, K. Johan; Filipsson, Monika E.M.

2015-01-01

Risk assessments of contaminated land often involve the use of generic bioconcentration factors (BCFs), which express contaminant concentrations in edible plant parts as a function of the concentration in soil, in order to assess the risks associated with consumption of homegrown vegetables. This study aimed to quantify variability in BCFs and evaluate the implications of this variability for human exposure assessments, focusing on cadmium (Cd) and lead (Pb) in lettuce and potatoes sampled around 22 contaminated glassworks sites. In addition, risks associated with measured Cd and Pb concentrations in soil and vegetable samples were characterized and a probabilistic exposure assessment was conducted to estimate the likelihood of local residents exceeding tolerable daily intakes. The results show that concentrations in vegetables were only moderately elevated despite high concentrations in soil, and most samples complied with applicable foodstuff legislation. Still, the daily intake of Cd (but not Pb) was assessed to exceed toxicological thresholds for about a fifth of the study population. Bioconcentration factors were found to vary more than indicated by previous studies, but decreasing BCFs with increasing metal concentrations in the soil can explain why the calculated exposure is only moderately affected by the choice of BCF value when generic soil guideline values are exceeded and the risk may be unacceptable. - Highlights: • Uptake of Cd and Pb by lettuce and potatoes increased with soil contamination. • Consumption of homegrown vegetables may lead to a daily Cd intake above TDIs. • The variability in the calculated BCFs is high when compared to previous studies. • Exposure assessments are most sensitive to the choice of BCFs at low contamination

Metal uptake by homegrown vegetables – The relative importance in human health risk assessments at contaminated sites

Energy Technology Data Exchange (ETDEWEB)

Augustsson, Anna L.M., E-mail: anna.augustsson@lnu.se [Department of Biology and Environmental Science, Linnaeus University, SE-391 82 Kalmar (Sweden); Uddh-Söderberg, Terese E. [Department of Biology and Environmental Science, Linnaeus University, SE-391 82 Kalmar (Sweden); Hogmalm, K. Johan [Department of Earth Sciences, University of Gothenburg, Gothenburg (Sweden); Filipsson, Monika E.M. [Department of Biology and Environmental Science, Linnaeus University, SE-391 82 Kalmar (Sweden)

2015-04-15

Risk assessments of contaminated land often involve the use of generic bioconcentration factors (BCFs), which express contaminant concentrations in edible plant parts as a function of the concentration in soil, in order to assess the risks associated with consumption of homegrown vegetables. This study aimed to quantify variability in BCFs and evaluate the implications of this variability for human exposure assessments, focusing on cadmium (Cd) and lead (Pb) in lettuce and potatoes sampled around 22 contaminated glassworks sites. In addition, risks associated with measured Cd and Pb concentrations in soil and vegetable samples were characterized and a probabilistic exposure assessment was conducted to estimate the likelihood of local residents exceeding tolerable daily intakes. The results show that concentrations in vegetables were only moderately elevated despite high concentrations in soil, and most samples complied with applicable foodstuff legislation. Still, the daily intake of Cd (but not Pb) was assessed to exceed toxicological thresholds for about a fifth of the study population. Bioconcentration factors were found to vary more than indicated by previous studies, but decreasing BCFs with increasing metal concentrations in the soil can explain why the calculated exposure is only moderately affected by the choice of BCF value when generic soil guideline values are exceeded and the risk may be unacceptable. - Highlights: • Uptake of Cd and Pb by lettuce and potatoes increased with soil contamination. • Consumption of homegrown vegetables may lead to a daily Cd intake above TDIs. • The variability in the calculated BCFs is high when compared to previous studies. • Exposure assessments are most sensitive to the choice of BCFs at low contamination.

Forage uptake of uranium series radionuclides in the vicinity of the anaconda uranium mill

International Nuclear Information System (INIS)

Rayno, D.R.; Momeni, M.H.; Sabau, C.

1980-01-01

Radiochemical analysis was performed on samples of soil and eight species of common vegetation growing on the Anaconda uranium mill site, located in New Mexico. The concentrations of the long-lived radionuclides U-238, U-234, Th-230, Ra-226, and Pb-210 in these forage plants were determined. The sampling procedures and analytical laboratory methods used are described. The highest radionuclide concentration found in a forage species was 130 pCi of Ra-226 per gram dry weight for grass growing on the main tailings pile at Anaconda, where the surface soil activity of Ra-226 was 236 pCi/g. A comparison of shoots activity with that of roots and soil was used to determine a distribution index and uptake coefficient for each species. The distribution index, the ratio of root activity to shoot activity, ranged from 0.30 (Th-230) in galleta grass (Hilaria jamesii) to 38.0 (Ra-226) in Indian ricegrass (Oryzopsis hymenoides). In nearly all instances, the roots contained higher radionuclide concentrations. The uptake coefficient, the ratio of vegetation activity to soil activity, ranged from 0.69 (U-238) in Indian ricegrass roots to 0.01 (U-238) in four-wing saltbush (Atriplex canescans) shoots. The range of radionuclide concentrations in plants growing on the Anaconda mill site is compared to that in vegetation from a control site 20 km away

Nutrient Uptake by High-Yielding Cotton Crop in Brazil

Directory of Open Access Journals (Sweden)

José Luís Vilela Vieira

2018-02-01

Full Text Available ABSTRACT: Determining nutrient uptake and accumulation rates by cotton crops is important to define management strategies, especially for transgenic varieties, which are cultivated using high-technology approaches that require substantial investment to maximize yield. Currently in Brazil, the states of Bahia and Mato Grosso are responsible for 84.4 % of the total cotton growing area. In the present study, two trials were conducted in 2013, one that involved planting FM 940 GLT, FM 980 GLT, and FM 913 GLT varieties in the state of Bahia and the other which involved FM 940 GLT and FM 980 GLT varieties in the state of Mato Grosso. The aim of the two trials was to represent the two regions that currently encompass the largest areas of cotton cultivation. Tissue samples, consisting of leaves, stems, and reproductive components, were collected eleven times during the crop cycle for determination of nutrient content and shoot dry matter. After weighing, plant tissue samples were dried and ground to determine nutrient contents. Because there were no overall differences in nutrient contents and biomass accumulation of the varieties during the crop cycle, we undertook joint analysis of the data from all varieties at each site. Favorable climatic conditions in Bahia promoted plant biomass production that was twice as much as plants grown in Mato Grosso, with cotton yields of 6.2 and 3.8 t ha−1 of lint and seed, respectively. The maximum nutrient accumulation occurred between 137-150 days after emergence (DAE for N; 143-148 for P; 172-185 for K; 100 for Ca; 144-149 for Mg; and 153-158 for S. Maximum uptake ranged from 218-362 kg ha−1 N; 26-53 kg ha−1 P; 233-506 kg ha−1 K; 91-202 kg ha−1 Ca; 28-44 kg ha−1 Mg; and 19-61 kg ha−1 S. On average, the sites revealed nutrient export of 14, 2, 23, 3, 2, and 2 kg t−1 of lint and seed for N, P, K, Ca, Mg, and S, respectively, with little variation among sites. Extraction of nutrients per area by cotton

Physiological FDG uptake in the palatine tonsils

International Nuclear Information System (INIS)

Kawabe, Joji; Okamura, Terue; Shakudo, Miyuki

2001-01-01

In clinical F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) studies of the head and neck region, remarkable symmetric tonsillar FDG uptake is sometimes observed. We determined the incidence and degree of tonsillar FDG uptake and investigated the significance of tonsillar FDG uptake. Between June 1998 and August 1998, we obtained informed consent from 17 patients who were scheduled to undergo a FDG-PET study for their own disease (11 men and 6 women; aged 22 to 77 yr) and who did not have head and neck disease to perform FDG-PET scanning of the head and neck region in addition to their target organs. The incidence and degree of tonsillar FDG uptake were determined. Remarkable tonsillar FDG uptake was found in 9 patients. The SUVs of these FDG uptakes ranged from 2.48 to 6.75, with a mean of 4.29±1.20 (SD). Tonsillar FDG uptakes in the remaining 8 patients were not remarkable, and their SUVs ranged from 1.93 to 3.31, with a mean of 2.46±0.45. Head and neck disease does not appear to have been responsible for the increase in tonsillar FDG uptake. Differences among tonsillar FDG uptake in these 17 patients without head and neck disease appear to reflect differences in activity of ''physiological'' inflammation of the palatine tonsils. (author)

Characteristics of competitive uptake between Microcystin-LR and natural organic matter (NOM) fractions using strongly basic anion exchange resins.

Science.gov (United States)

Dixit, Fuhar; Barbeau, Benoit; Mohseni, Madjid

2018-03-29

Microcystins are the most commonly occurring cyanotoxins, and have been extensively studied across the globe. In the present study, a strongly basic anion exchange resin was employed to investigate the removal of Microcystin-LR (MCLR), one of the most toxic microcystin variants. Factors influencing the uptake behavior included the MCLR and resin concentrations, resin dosage, and natural organic matter (NOM) characteristics, specifically, the charge density and molecular weight distribution of source water NOM. Equivalent background concentration (EBC) was employed to evaluate the competitive uptake between NOM and MCLR. The experimental data were compared with different mathematical and physical models and pore diffusion was determined as the rate-limiting step. The resin dose/solute concentration ratio played a key role in the MCLR uptake process and MCLR removal was attributed primarily to electrostatic attractions. Charge density and molecular weight distribution of the background NOM fractions played a major role in MCLR removal at lower resin dosages (200 mg/L ∼ 1 mL/L and below), where a competitive uptake was observed due to the limited exchange sites. Further, evidences of pore blockage and site reduction were also observed in the presence of humics and larger molecular weight organic fractions, where a four-fold reduction in the MCLR uptake was observed. Comparable results were obtained for laboratory studies on synthetic laboratory water and surface water under similar conditions. Given their excellent performance and low cost, anion exchange resins are expected to present promising potentials for applications involving the removal of removal of algal toxins and NOM from surface waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

A simplified method for active-site titration of lipases immobilised on hydrophobic supports.

Science.gov (United States)

Nalder, Tim D; Kurtovic, Ivan; Barrow, Colin J; Marshall, Susan N

2018-06-01

The aim of this work was to develop a simple and accurate protocol to measure the functional active site concentration of lipases immobilised on highly hydrophobic supports. We used the potent lipase inhibitor methyl 4-methylumbelliferyl hexylphosphonate to titrate the active sites of Candida rugosa lipase (CrL) bound to three highly hydrophobic supports: octadecyl methacrylate (C18), divinylbenzene crosslinked methacrylate (DVB) and styrene. The method uses correction curves to take into account the binding of the fluorophore (4-methylumbelliferone, 4-MU) by the support materials. We showed that the uptake of the detection agent by the three supports is not linear relative to the weight of the resin, and that the uptake occurs in an equilibrium that is independent of the total fluorophore concentration. Furthermore, the percentage of bound fluorophore varied among the supports, with 50 mg of C18 and styrene resins binding approximately 64 and 94%, respectively. When the uptake of 4-MU was calculated and corrected for, the total 4-MU released via inhibition (i.e. the concentration of functional lipase active sites) could be determined via a linear relationship between immobilised lipase weight and total inhibition. It was found that the functional active site concentration of immobilised CrL varied greatly among different hydrophobic supports, with 56% for C18, compared with 14% for DVB. The described method is a simple and robust approach to measuring functional active site concentration in immobilised lipase samples. Copyright © 2018 Elsevier Inc. All rights reserved.

Antigen Uptake during Different Life Stages of Zebrafish (Danio rerio Using a GFP-Tagged Yersinia ruckeri.

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Rozalia Korbut

Full Text Available Immersion-vaccines (bacterins are routinely used for aquacultured rainbow trout to protect against Yersinia ruckeri (Yr. During immersion vaccination, rainbow trout take up and process the antigens, which induce protection. The zebrafish was used as a model organism to study uptake mechanisms and subsequent antigen transport in fish. A genetically modified Yr was developed to constitutively express green fluorescent protein (GFP and was used for bacterin production. Larval, juvenile and adult transparent zebrafish (tra:nac mutant received a bath in the bacterin for up to 30 minutes. Samples were taken after 1 min, 15 min, 30 min, 2 h, 12 h and 24 h. At each sampling point fish were used for live imaging of the uptake using a fluorescence stereomicroscope and for immunohistochemistry (IHC. In adult fish, the bacterin could be traced within 30 min in scale pockets, skin, oesophagus, intestine and fins. Within two hours post bath (pb Yr-antigens were visible in the spleen and at 24 h in liver and kidney. Bacteria were associated with the gills, but uptake at this location was limited. Antigens were rarely detected in the blood and never in the nares. In juvenile fish uptake of the bacterin was seen in the intestine 30 min pb and in the nares 2 hpb but never in scale pockets. Antigens were detected in the spleen 12 hpb. Zebrafish larvae exhibited major Yr uptake only in the mid-intestine enterocytes 24 hpb. The different life stages of zebrafish varied with regard to uptake locations, however the gut was consistently a major uptake site. Zebrafish and rainbow trout tend to have similar uptake mechanisms following immersion or bath vaccination, which points towards zebrafish as a suitable model organism for this aquacultured species.

Flow-cytometric determination of high-density-lipoprotein binding sites on human leukocytes

International Nuclear Information System (INIS)

Schmitz, G.; Wulf, G.; Bruening, T.A.; Assmann, G.

1987-01-01

In this method, leukocytes were isolated from 6 mL of EDTA-blood by density-gradient centrifugation and subsequently incubated with rhodamine isothiocyanate (RITC)-conjugated high-density lipoproteins (HDL). The receptor-bound conjugate particles were determined by fluorescent flow cytometry and compared with 125 I-labeled HDL binding data for the same cells. Human granulocytes express the highest number of HDL binding sites (9.4 x 10(4)/cell), followed by monocytes (7.3 x 10(4)/cell) and lymphocytes (4.0 x 10(4)/cell). Compared with conventional analysis of binding of 125 I-labeled HDL in tissue-culture dishes, the present determination revealed significantly lower values for nonspecific binding. In competition studies, the conjugate competes for the same binding sites as 125 I-labeled HDL. With the use of tetranitromethane-treated HDL3, which fails to compete for the HDL receptor sites while nonspecific binding is not affected, we could clearly distinguish between 37 degrees C surface binding and specific 37 degrees C uptake of RITC-HDL3, confirming that the HDL receptor leads bound HDL particles into an intracellular pathway rather than acting as a docking type of receptor. Patients with familial dysbetalipoproteinemia showed a significantly higher number of HDL binding sites in the granulocyte population but normal in lymphocytes and monocytes, indicating increased uptake of cholesterol-containing lipoproteins. In patients with familial hypercholesterolemia, HDL binding was increased in all three cell types, indicating increased cholesterol uptake and increased cholesterol synthesis. The present method allows rapid determination of HDL binding sites in leukocytes from patients with various forms of hyper- and dyslipoproteinemias

Hydrogen uptake by Azolla-Anabaena

International Nuclear Information System (INIS)

Ruschel, A.P.; Freitas, J.R. de; Silva, P.M.

1984-01-01

The hydrogen uptake in the Azolla-Anabaena system is studied. Tritium is used as tracer. Plants are incubated under different atmosphere composition: a) Air + 3 H 2 ; b) Air + CO 2 + 3 H 2 + CO; c) Air + 3 H 2 + CO; d) Air + CO 2 + 3 H 2 + CO to study the pathway of absorbed hydrogen in the Azolla - Anabaena system. Azolla-Anabaena showed greater hydrogen uptake under argonium atmosphere than under air. Carbon monoxide decreased hydrogen uptake. There are evidences of recycling of the hydrogen evolved through notrogenease. (Author) [pt

Effect of pH on tumor cell uptake of radiogallium in vitro and in vivo

International Nuclear Information System (INIS)

Vallabhajosula, S.R.; Hartwig, J.F.; Wolf, W.

1982-01-01

When injected at tracer levels into the blood, radiogallium as 67 Ga-citrate binds to, and is transported to, the site of the tumor by transferrin. The process by which transferrin-bound Ga is converted to tumor-bound Ga is not fully unterstood, but may involve the differential physicology of neoplasmas compared with normal tissues. Based on the slight acidity known to be exhibited by the extracellular fluid of many animal and human tumors, we have studied the effect of pH on stability and dissociation of the Ga-transferrin complex and on the uptake of Ga by tumor cells in vitro and animal tumors in vivo. When plasma from rabbits injected with 67 Ga-citrate was dialyzed at pH 6.5-7.5, disociation of Ga from transferrin showed an inverse pH-dependence. A similar inverse dependence on pH was observed for the uptake of Ga by L1210 leukemia cells and Ehrlich ascites cells incubated with Ga-transferrin complex. Tumor uptake of Ga in rats bearing Walker-256 carcinosarcoma or Murphystum lymphosarcoma whose tumor pH had been further lowered by administration of glucose showed a statistically significant increase over control rats receiving no glucose. These results demonstrate that the stability of the Ga-transferrin complex is pH-dependent and suggest that dissociation of this complex due to decreased pH at the tumor site may be one factor involved in tumor localization and binding of Ga. (orig.)

Variability in uptake of Cs isotopes by fenugreek plant from three soils

Energy Technology Data Exchange (ETDEWEB)

Pulhani, V; Dafauti, S; Dahiya, S; Hedge, A G [Environmental Studies Section, Health Physics Div., Bhabha Atomic Research Centre, Mumbai (India)

2008-07-01

Soil to plant transfer via root uptake is one of the major compartments in the radionuclide transfer pathways to man and can be used to assess the internal radiation dose via ingestion. The variability in the Transfer Factor (TF) of Cs isotopes was investigated in three different soils from nuclear power plant sites at Rajasthan and Narora with alkaline sandy loam alluvial and Madras with acidic coastal sandy loam alluvial soil. The soils were characterized for soil properties like texture, pH, EC, organic carbon, CaCO{sub 3} (%), CEC, silt, clay sand etc. and spiked with a mixture of 800 Bq {sup 137}Cs, 300 Bq {sup 134}Cs and 10mg of {sup 133}Cs (stable). Fenugreek (Trigonella foenum-graecum L.) from Leguminosae family an annual plant commonly used as a vegetable was grown in these soils to study the uptake of Cs. The uptake of heavy toxic elements like Pb, Cd, Ni, Cr etc. and nutrients Fe, Co, Cu, Zn, Mn, Ca, Mg, Na and K was also studied. The uptake of heavy toxic elements like Pb, Cd, Ni, Cr etc. and nutrients Fe, Co, Cu, Zn, Mn, Ca, Mg, Na and K was also studied. {sup 137}Cs and{sup 134}Cs was estimated using HPGe detector (15% Relative Efficiency, 54cc-coaxial, 2keV resolution at 1332keV of {sup 60}Co). Stable Cs, K and Na were determined by the Atomic Emission Spectrophotometry and Pb, Cd, Cr etc. by Atomic Absorption Spectrophotometry. Among the three soils the transfer factor for all the elements and Cs was highest for MAPS due to higher organic matter content and acidic pH followed by NAPS and RAPS. The {sup 137}Cs and {sup 134}Cs isotopes have been taken up to the same extent from soil and transfer factors are similar to each other. But the stable Cs uptake appears to be slightly high, probably because of excess of {sup 133}Cs (mg level) added as compared to the radioactive isotopes. In spite of this high difference in the soil concentrations of Cs isotopes, uptake of {sup 133}Cs is not very high indicating to a physiological limiting process for uptake

Uptake of benzyladenine by excised watermelon cotyledons.

Science.gov (United States)

Lampugnani, M G; Fantelli, R; Longo, G P; Longo, C P; Rossi, G

1981-07-01

The uptake of 8-[(14)C]N(6)-benzyladenine (BA) was studied in excised watermelon (Citrullus vulgaris Schrad.) cotyledons 24 hours after the start of imbibition. The passive nature of this uptake is suggested by the following evidence: (a) no sign of saturation on increasing external concentration of BA; (b) no decrease in uptake under conditions that inhibit ATP synthesis; (c) no change in amount of radioactivity absorbed when cotyledons are frozen and thawed before the uptake test. About two-thirds of the radioactivity taken up is released after 12 hours of washing. If the washing is performed at 2 C very little radioactivity is released.There seems to be a correlation between the level of radioactivity (i.e. of BA + derivatives) present in the cotyledons and the magnitude of hormonal responses that are observed four days after uptake. This relationship holds regardless of whether a given level of radioactivity has been reached after a short period of uptake or after a long period of uptake followed by washing.

A local renal renin-angiotensin system activation via renal uptake of prorenin and angiotensinogen in diabetic rats.

Science.gov (United States)

Tojo, Akihiro; Kinugasa, Satoshi; Fujita, Toshiro; Wilcox, Christopher S

2016-01-01

The mechanism of activation of local renal renin-angiotensin system (RAS) has not been clarified in diabetes mellitus (DM). We hypothesized that the local renal RAS will be activated via increased glomerular filtration and tubular uptake of prorenin and angiotensinogen in diabetic kidney with microalbuminuria. Streptozotocin (STZ)-induced DM and control rats were injected with human prorenin and subsequently with human angiotensinogen. Human prorenin uptake was increased in podocytes, proximal tubules, macula densa, and cortical collecting ducts of DM rats where prorenin receptor (PRR) was expressed. Co-immunoprecipitation of kidney homogenates in DM rats revealed binding of human prorenin to the PRR and to megalin. The renal uptake of human angiotensinogen was increased in DM rats at the same nephron sites as prorenin. Angiotensin-converting enzyme was increased in podocytes, but decreased in the proximal tubules in DM rats, which may have contributed to unchanged renal levels of angiotensin despite increased angiotensinogen. The systolic blood pressure increased more after the injection of 20 μg of angiotensinogen in DM rats than in controls, accompanied by an increased uptake of human angiotensinogen in the vascular endothelium. In conclusion, endocytic uptake of prorenin and angiotensinogen in the kidney and vasculature in DM rats was contributed to increased tissue RAS and their pressor response to angiotensinogen.

Gastric gallium-67 uptake in gastritis

International Nuclear Information System (INIS)

Yeh, E.L.; Tisdale, P.L.; Zielonka, J.S.

1983-01-01

Even though Ga-67 imaging has been used widely in the diagnosis of malignant as well as inflammatory lesions, its uptake in the stomach has been reported in the literature mainly in gastric lymphoma and carcinoma. As shown in this case, intense gastric uptake of the radionuclide may be seen in common gastritis without malignancy. Perhaps the benign gastric uptake of Ga-67 deserves more emphasis

Transcription factor activating protein 2 beta (TFAP2B) mediates noradrenergic neuronal differentiation in neuroblastoma.

Science.gov (United States)

Ikram, Fakhera; Ackermann, Sandra; Kahlert, Yvonne; Volland, Ruth; Roels, Frederik; Engesser, Anne; Hertwig, Falk; Kocak, Hayriye; Hero, Barbara; Dreidax, Daniel; Henrich, Kai-Oliver; Berthold, Frank; Nürnberg, Peter; Westermann, Frank; Fischer, Matthias

2016-02-01

Neuroblastoma is an embryonal pediatric tumor that originates from the developing sympathetic nervous system and shows a broad range of clinical behavior, ranging from fatal progression to differentiation into benign ganglioneuroma. In experimental neuroblastoma systems, retinoic acid (RA) effectively induces neuronal differentiation, and RA treatment has been therefore integrated in current therapies. However, the molecular mechanisms underlying differentiation are still poorly understood. We here investigated the role of transcription factor activating protein 2 beta (TFAP2B), a key factor in sympathetic nervous system development, in neuroblastoma pathogenesis and differentiation. Microarray analyses of primary neuroblastomas (n = 649) demonstrated that low TFAP2B expression was significantly associated with unfavorable prognostic markers as well as adverse patient outcome. We also found that low TFAP2B expression was strongly associated with CpG methylation of the TFAP2B locus in primary neuroblastomas (n = 105) and demethylation with 5-aza-2'-deoxycytidine resulted in induction of TFAP2B expression in vitro, suggesting that TFAP2B is silenced by genomic methylation. Tetracycline inducible re-expression of TFAP2B in IMR-32 and SH-EP neuroblastoma cells significantly impaired proliferation and cell cycle progression. In IMR-32 cells, TFAP2B induced neuronal differentiation, which was accompanied by up-regulation of the catecholamine biosynthesizing enzyme genes DBH and TH, and down-regulation of MYCN and REST, a master repressor of neuronal genes. By contrast, knockdown of TFAP2B by lentiviral transduction of shRNAs abrogated RA-induced neuronal differentiation of SH-SY5Y and SK-N-BE(2)c neuroblastoma cells almost completely. Taken together, our results suggest that TFAP2B is playing a vital role in retaining RA responsiveness and mediating noradrenergic neuronal differentiation in neuroblastoma. Copyright © 2015 Federation of European Biochemical Societies

Specificity of cellular DNA-binding sites of microbial populations in a Florida reservoir

International Nuclear Information System (INIS)

Paul, J.H.; Pichard, S.L.

1989-01-01

The substrate specificity of the DNA-binding mechanism(s) of bacteria in a Florida reservoir was investigated in short- and long-term uptake studies with radiolabeled DNA and unlabeled competitors. Thymine oligonucleotides ranging in size from 2 base pairs to 19 to 24 base pairs inhibited DNA binding in 20-min incubations by 43 to 77%. Deoxynucleoside monophosphates, thymidine, and thymine had little effect on short-term DNA binding, although several of these compounds inhibited the uptake of the radiolabel from DNA in 4-h incubations. Inorganic phosphate and glucose-1-phosphate inhibited neither short- nor long-term binding of [ 3 H]- or [ 32 P]DNA, indicating that DNA was not utilized as a phosphorous source in this reservoir. RNA inhibited both short- and long-term radiolabeled DNA uptake as effectively as unlabeled DNA. Collectively these results indicate that aquatic bacteria possess a generalized nuclei acid uptake/binding mechanism specific for compounds containing phosphodiester bonds and capable of recognizing oligonucleotides as short as dinucleotides. This binding site is distinct from nucleoside-, nucleotide-, phosphomonoester-, and inorganic phosphate-binding sites. Such a nucleic acid-binding mechanism may have evolved for the utilization of extracellular DNA (and perhaps RNA), which is abundant in many marine and freshwater environments

Attempt at ESR dating of tooth enamel of French middle pleistocene sites

International Nuclear Information System (INIS)

Bahain, J.J.; Sarcia, M.N.; Falgueres, C.; Yokoyama, Y.

1993-01-01

Tooth enamel samples from four important French middle Pleistocene sites are analyzed by the ESR method. ESR ages were calculated using uranium uptake mathematical models and compared with U-series results. (author)

21 CFR 862.1715 - Triiodothyronine uptake test system.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Triiodothyronine uptake test system. 862.1715... Systems § 862.1715 Triiodothyronine uptake test system. (a) Identification. A triiodothyronine uptake test... plasma. Measurements of triiodothyronine uptake are used in the diagnosis and treatment of thyroid...

Increased mRNA expression of cytochrome oxidase in dorsal raphe nucleus of depressive suicide victims

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A Sanchez-Bahillo

2008-04-01

serotonin re-uptake. No alteration was found in noradrenergic neurons, suggesting that they play no crucial role in the suicidal behavior of depressive patients.Keywords: depression, suicidal behavior, dorsal raphe nucleus, noradrenergic neurons

Poly (D,L-lactide-co-glycolide nanoparticles: Uptake by epithelial cells and cytotoxicity

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J. H. Hamman

2014-03-01

Full Text Available Nanoparticles as drug delivery systems offer benefits such as protection of the encapsulated drug against degradation, site-specific targeting and prolonged blood circulation times. The aim of this study was to investigate nanoparticle uptake into Caco-2 cell monolayers, their co-localization within the lysosomal compartment and their cytotoxicity in different cell lines. Rhodamine-6G labelled poly(D,L-lactide-co-glycolide (PLGA nanoparticles were prepared by a double emulsion solvent evaporation freeze-drying method. Uptake and co-localisation of PLGA nanoparticles in lysosomes were visualized by confocal laser scanning microscopy. The cytotoxicity of the nanoparticles was evaluated on different mammalian cells lines by means of Trypan blue exclusion and the MTS assay. The PLGA nanoparticles accumulated in the intercellular spaces of Caco-2 cell monolayers, but were also taken up transcellularly into the Caco-2 cells and partially co-localized within the lysosomal compartment indicating involvement of endocytosis during uptake. PLGA nanoparticles did not show cytotoxic effects in all three cell lines. Intact PLGA nanoparticles are therefore capable of moving across epithelial cell membranes partly by means of endocytosis without causing cytotoxic effects.

Uptake of myocardial imaging agents by rejected hearts

International Nuclear Information System (INIS)

Bergsland, J.; Carr, E.A.; Carroll, M.; Wright, J.W.; Feldman, M.J.; Massucci, J.; Bhayana, J.N.; Gona, J.M.

1985-01-01

Technetium 99 m pyrophosphate, Gallium 67 and Thallium 201 uptakes were measured in heterotopically transplanted rat hearts. Five days after transplantation, Technetium 99 m pyrophosphate, and Gallium 67 uptakes were significantly higher in allogeneic grafts than in syngeneic grafts. At an early stage of rejection (three days after transplantation), only Technetium 99 m pyrophosphate uptake in the left ventricle of allogeneic grafts showed a significant difference (p less than 0.04). At five days, Thallium 201 uptake was significantly lower in allo- than syngeneic grafts. There was a positive correlation between radionuclide uptake and histologic degree of rejection for Technetium 99 m pyrophosphate and Gallium 67 while Thallium 201 uptake correlated negatively. Analysis of variance revealed that hearts with no or minimal rejection had statistically different uptakes than hearts with mild to moderate rejection. These results suggest that uptake of imaging agents might be useful in the diagnosis of rejection of the transplanted heart

Benign oral pathology as a cause of false positive 131I uptake in thyroid carcinoma

International Nuclear Information System (INIS)

Mansberg, R.; Wadhwa, S.S.; Fernandes, V.B.

1997-01-01

Full text: We present three thyroidectomised patients with a history of thyroid carcinoma who had non-metastatic 131 I uptake due to benign oral pathology. A salivary gland study suggested impaired function but no obstruction was demonstrated on a sialogram. The symptoms resolved on antibiotic therapy and a subsequent 131 I study was normal. A subsequent thallium study demonstrated physiological tracer distribution. A 35-year-old female with papillary cell carcinoma of the thyroid demonstrated a focus of uptake on the right hemi-mandible following both a diagnostic and a therapeutic dose of 131 I. This area was tender and an OPG confirmed an area of liquefaction at this site. A 53-year-old female with medullary cell carcinoma of the thyroid demonstrated a focus of uptake in the right side of the maxilla following a diagnostic administration of 131 I. An OPG confirmed an area of liquefaction around the apex of the right upper centre. These three cases illustrate salivary gland and dental inflammation as causes of false positive 131 I uptake. It is important to differentiate non-metastatic 131 I uptake from that due to functioning metastatic thyroid carcinoma in order to avoid inappropriate treatment with large additional doses of 131 I. As in these patients, clinical assessment and the use of anatomical imaging or other isotopes such as thallium or technetium can be helpful in ruling out a mistaken diagnosis of metastasis

Uptake and transport of chromium in plants

International Nuclear Information System (INIS)

Ramachandran, V.; D'souza, T.J.; Mistry, K.B.

1980-01-01

The uptake of chromium, an important soil and water pollutant, by five different plant species was examined in nutrient culture experiments using chromium-51 as a tracer. The concentration in aerial tissues of both trivalent and hexavalent forms of chromium was the greatest in peas followed by beans, tomato and the cereals over identical uptake periods. The uptake of 51 Cr 3+ was, in general, greater than 51 CrO 4 2- . Studies with bean plants indicated that shoot uptake of both forms of chromium decreased with increasing pH and salt concentration of the external solution. Concentrations of 10 -4 M and 10 -5 M DNP inhibited 51 Cr uptake by bean shoots. (author)

Radioiodine uptake measurements in thyroid

International Nuclear Information System (INIS)

Kadireshn, A.; Kapur, S.C.; Samuel, J.R.; Mahajan, M.K.

1988-01-01

Evaluation of thyroid function can be carried out by measuring the uptake of orally administered radioactive iodine. The results of the thyroid uptake measurements for the period 1982-1987 in Christian Medical College, Ludhiana are presented here. About 3000 patients were screened during the analysis period. (author)

Plant Uptake of Atmospheric Carbonyl Sulfide in Coast Redwood Forests

Science.gov (United States)

Campbell, J. E.; Whelan, M. E.; Berry, J. A.; Hilton, T. W.; Zumkehr, A.; Stinecipher, J.; Lu, Y.; Kornfeld, A.; Seibt, U.; Dawson, T. E.; Montzka, S. A.; Baker, I. T.; Kulkarni, S.; Wang, Y.; Herndon, S. C.; Zahniser, M. S.; Commane, R.; Loik, M. E.

2017-12-01

The future resilience of coast redwoods (Sequoia sempervirens) is now of critical concern due to the detection of a 33% decline in California coastal fog over the 20th century. However, ecosystem-scale measurements of photosynthesis and stomatal conductance are challenging in coast redwood forests, making it difficult to anticipate the impacts of future changes in fog. To address this methodological problem, we explore coastal variations in atmospheric carbonyl sulfide (COS or OCS), which could potentially be used as a tracer of these ecosystem processes. We conducted atmospheric flask campaigns in coast redwood sites, sampling at surface heights and in the canopy ( 70 m), at the University of California Landels-Hill Big Creek Reserve and Big Basin State Park. We simulated COS atmosphere-biosphere exchange with a high-resolution 3-D model to interpret these data. Flask measurements indicated a persistent daytime drawdown between the coast and the downwind forest (45 ± 6 ppt COS) that is consistent with the expected relationship between COS plant uptake, stomatal conductance, and gross primary production. Other sources and sinks of COS that could introduce noise to the COS tracer technique (soils, anthropogenic activity, nocturnal plant uptake, and surface hydrolysis on leaves) are likely to be small relative to daytime COS plant uptake. These results suggest that COS measurements may be useful for making ecosystem-scale estimates of carbon, water, and energy exchange in coast redwood forests.

Factors affecting 18 F FDOPA standardized uptake value in patients with primary brain tumors after treatment

International Nuclear Information System (INIS)

Chiaravalloti, Agostino; Fiorentini, Alessandro; Villani, Veronica; Carapella, Carmine; Pace, Andrea; Di Pietro, Barbara; Di Russo, Carmen; Palumbo, Barbara; Floris, Roberto; Schillaci, Orazio

2015-01-01

Aim: To investigate the factors affecting 18 F FDOPA uptake in patients with primary brain tumors (PBT) after treatment. Materials and methods: 97 patients with PBT (6 were grade I, 40 were grade II, 29 were grade III and 22 were grade IV) underwent 18 F FDOPA positron emission tomography/computed tomography (PET/CT) after treatment. Intervals from surgery, chemotherapy (CHT) and radiotherapy (RT) were 41.48 (± 42.27), 16.04 (± 29.08) and 28.62 (± 34.49) months respectively. Results: 18 F FDOPA uptake in the site of recurrence was not related to the interval from surgery and CHT while a significant relationship has been found with the interval from RT and tumor grade. Conclusions: The results of our study show that the interval from RT and the grade of PBT should be considered carefully when evaluating brain PET/CT scans since these factors could directly affect 18 F FDOPA uptake

Octreotide Uptake in Parathyroid Adenoma

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Seyhan Karaçavuş

2012-08-01

Full Text Available The patient with a history of bone pain and muscle weakness, was thought to have oncogenic osteomalacia as a result of biochemical investigations and directed to Nuclear Medicine Department for a whole-body bone scintigraphy and 111In-octreotide scintigraphy. There was no focal pathologic tracer uptake, but generalized marked increase in skeletal uptake on bone scintigraphy. Octreotide scintigraphy showed accumulation of octreotide in the region of the left lobe of the thyroid gland in the neck. Thereafter, parathyroid scintigraphy was performed with technetium-99m labeled metroxy-isobutyl-isonitryl (99mTc-MIB and MIBI scan demonstrated radiotracer uptake at the same location with octreotide scintigraphy. The patient underwent left inferior parathyroidectomy and histopathology confirmed a parathyroid adenoma. Somatostatin receptor positive parathyroid adenoma may show octreotide uptake. Octreotide scintigraphy may be promising and indicate a possibility of using somatostatin analogues for the medical treatment of somatostatin receptor positive parathyroid tumors. (MIRT 2012;21:77-79

Sudden increase in atmospheric concentration reveals strong coupling between shoot carbon uptake and root nutrient uptake in young walnut trees

International Nuclear Information System (INIS)

Delaire, M.; Sigogne, M.; Beaujard, F.; Frak, E.; Adam, B.; Le Roux, X.

2005-01-01

Short-term effects of a sudden increase in carbon dioxide concentration on nutrient uptake by roots during vegetative growth was studied in young walnut trees. Rates of carbon dioxide uptake and water loss by individual trees were determined by a branch bag method from three days before and six days after carbon dioxide concentration was increased. Nutrient uptake rates were measured concurrently by a hydroponic recirculating nutrient solution system. Carbon dioxide uptake rates increased greatly with increasing atmospheric carbon dioxide; nutrient uptake rates were proportional to carbon dioxide uptake rates, except for the phosphorus ion. Daily water loss rates were only slightly affected by elevated carbon dioxide. Overall, it was concluded that in the presence of non-limiting supplies of water and nutrients, root nutrient uptake and shoot carbon assimilation are strongly coupled in the short term in young walnut trees despite the important carbon and nutrient storage capacities od woody species. 45 refs., 7 figs

The effects of water management on the CO2 uptake of Sphagnum moss in a reclaimed peatland

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C.M. Brown

2017-07-01

Full Text Available To harvest Sphagnum on a cyclic basis and rapidly accumulate biomass, active water management is necessary. The goal of this study is to determine the hydrological conditions that will maximise CO2 uptake in Sphagnum farming basins following the moss-layer transfer technique. Plot CO2 uptake doubled from the first growing season to the second, but growth was not uniform across the site. Results indicate that the seasonal oscillations in water table (WT position were more important than actual WT position for estimating Sphagnum ground cover and CO2 uptake when the seasonal WT is shallow (< -25 cm. Plots with higher productivity had a WT range (seasonal maximum – minimum less than 15 cm, a WT position which did not fluctuate more than ± 7.5 cm, and a low WT standard deviation. Each basin was a CO2 source during the second growing season, and seasonal modelled NEE ranged from 107.1 to 266.8 g CO2 m-2. Decomposition from the straw mulch accounted for over half of seasonal respiration, and the site is expected to become a CO2 sink as the straw mulch decomposes and moss cover increases. This study highlights the importance of maintaining stable moisture conditions to increase Sphagnum growth and CO2 sink functions.

Aquaporins and root water uptake

Science.gov (United States)

Water is one of the most critical resources limiting plant growth and crop productivity, and root water uptake is an important aspect of plant physiology governing plant water use and stress tolerance. Pathways of root water uptake are complex and are affected by root structure and physiological res...

Cell uptake survey of pegylated nanographene oxide.

Science.gov (United States)

Vila, M; Portolés, M T; Marques, P A A P; Feito, M J; Matesanz, M C; Ramírez-Santillán, C; Gonçalves, G; Cruz, S M A; Nieto, A; Vallet-Regi, M

2012-11-23

Graphene and more specifically, nanographene oxide (GO) has been proposed as a highly efficient antitumoral therapy agent. Nevertheless, its cell uptake kinetics, its influence in different types of cells and the possibility of controlling cellular internalization timing, is still a field that remains unexplored. Herein, different cell types have been cultured in vitro for several incubation periods in the presence of 0.075 mg ml(-1) pegylated GO solutions. GO uptake kinetics revealed differences in the agent's uptake amount and speed as a function of the type of cell involved. Osteoblast-like cells GO uptake is higher and faster without resulting in greater cell membrane damage. Moreover, the dependence on the commonly used PEG nature (number of branches) also influences the viability and cell uptake speed. These facts play an important role in the future definition of timing parameters and selective cell uptake control in order to achieve an effective therapy.

Cell uptake survey of pegylated nanographene oxide

International Nuclear Information System (INIS)

Vila, M; Nieto, A; Vallet-Regi, M; Portolés, M T; Feito, M J; Matesanz, M C; Ramírez-Santillán, C; Marques, P A A P; Gonçalves, G; Cruz, S M A

2012-01-01

Graphene and more specifically, nanographene oxide (GO) has been proposed as a highly efficient antitumoral therapy agent. Nevertheless, its cell uptake kinetics, its influence in different types of cells and the possibility of controlling cellular internalization timing, is still a field that remains unexplored. Herein, different cell types have been cultured in vitro for several incubation periods in the presence of 0.075 mg ml −1 pegylated GO solutions. GO uptake kinetics revealed differences in the agent’s uptake amount and speed as a function of the type of cell involved. Osteoblast-like cells GO uptake is higher and faster without resulting in greater cell membrane damage. Moreover, the dependence on the commonly used PEG nature (number of branches) also influences the viability and cell uptake speed. These facts play an important role in the future definition of timing parameters and selective cell uptake control in order to achieve an effective therapy. (paper)

Comparative uptake of uranium, thorium, and plutonium by biota inhabiting a contaminated Tennessee floodplain

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Bondietti, E.A.; Walker, R.L.

1981-01-01

The uptake of 238 U, 232 Th, and 239 Pu from soil by fescue, grasshoppers, and small mammals was compared at the contaminated White Oak Creek floodplain in East Tennessee. Comparisons of actinide uptake were based on analyses of radionuclide ratios (U/Pu and Th/Pu) in soil and biota. U:Pu ratios in small mammal carcasses (shrews, mice, and rats) and bone samples from larger mammals (rabbit, woodchuck, opossum, and raccoon) were significantly greater (P less than or equal to 0.05) than U/Pu ratios in soil (based on 8M HNO 3 extractable). There was no significant difference between Th/Pu ratios in animals and soil. The order of actinide accumulation by biota from the site relative to contaminated soil was U > Th approx. = Pu

99mTc-DPD uptake in juvenile arthritis

International Nuclear Information System (INIS)

Stender Hansen, E.; Holm, I.E.; Buenger, C.; Knudsen, V.; Noer, I.; Bach Christensen, S.

1986-01-01

Unilateral arthritis of the knee was induced in mongrel puppies by intraarticular injections of 1% Carragheenan. Bone metabolism was studied by a scintimetric technique on static 99m Tc-diphosphonate bone scans every 2nd week during the induction of arthritis for 3 months and monthly in a postarthritic phase of another 3 months. Changes in uptake of radionuclide were present after 2 weeks. The induction phase was characterized by a decreased uptake in the calcification layer of the juxta-articular growth plates and a moderately increased epiphyseal uptake. The postarthritic phase was characterized by normalization of growth plate uptake and a marked increase in epiphyseal uptake. Using contact autoradiography, the epiphyseal uptake was seen mainly in a narrow subchondral and subsynovial bone layer, around bone cysts and osteophytes, whereas central epiphyseal bone was osteopenic with decreased uptake of tracer. The study suggests that the early scintigraphic appearance of juvenile non-suppurative arthritis may be an overall decrease in uptake of 99m Tc-diphosphonate due to a depression of growth plate metabolism. (author)

Uptake of Total Petroleum Hydrocarbon (TPH) and Polycyclic Aromatic Hydrocarbons (PAHs) by Oryza sativa L. Grown in Soil Contaminated with Crude Oil.

Science.gov (United States)

Patowary, Rupshikha; Patowary, Kaustuvmani; Devi, Arundhuti; Kalita, Mohan Chandra; Deka, Suresh

2017-01-01

The purpose of this study was to determine whether total petroleum hydrocarbon (TPH) and polycyclic aromatic hydrocarbons (PAHs) present in crude oil contaminated sites are transferred to roots, shoots and finally the grains of rice crops (Oryza sativa L.) grown in those sites. Soil was artificially contaminated with crude oil at concentrations of 0, 1000, 5000, 10,000, and 15,000 mg/kg, followed by planting of rice seedlings. After harvest, TPH in plant samples were measured, and it was determined that the uptake of TPH by the plants gradually increased as the concentration of oil in soil increased. Further, from GC-MS analysis, it was observed that PAHs including naphthalene and phenanthrene bioaccumulated in rice plant parts. Vital physico-chemical properties of soil were also altered due to crude oil contamination. Our study revealed that rice plants grown in crude oil polluted sites can uptake TPH including PAHs, thus emphasising the importance of prior investigation of soil condition before cultivation of crops.

21 CFR 868.1730 - Oxygen uptake computer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oxygen uptake computer. 868.1730 Section 868.1730...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1730 Oxygen uptake computer. (a) Identification. An oxygen uptake computer is a device intended to compute the amount of oxygen consumed by a...

Uptake and disposition of mirex in hepatocytes and subcellular fractions in CD1 mouse liver

International Nuclear Information System (INIS)

Charles, A.K.; Rosenbaum, D.P.; Ashok, L.; Abraham, R.

1985-01-01

In vivo uptake and disposition of [ 14 C]mirex by CD1 mouse liver subcellular fractions and cells of different nuclear ploidy were examined following single or multiple doses of mirex injected intraperitoneally. Significant amounts of mirex were rapidly taken up by liver (21-29%), suggesting that liver is one of the primary sites of accumulation of the chemical. Among subcellular fractions, mirex was predominantly distributed in mitochondria and microsomes in the irreversibly bound form (about 20%), although its levels fluctuated considerably with time. Mirex was completely dissociated with trichloroacetic acid treatment from both nuclear and plasma membrane fractions, although the total uptake by these fractions was markedly high. The time course of uptake and concentration-dependent disposition of mirex revealed that polyploid hepatocytes selectively accumulated higher amounts of the chemical (two to three times) compared to diploid hepatocytes. The increased affinity of polyploid cells to mirex may indicate a greater susceptibility of this cell type to the chemical insult and also may suggest a possible early involvement of polyploids in the tumorigenic process in rodent livers

Heavy metals and their radionuclides uptake by Bacillus Licheniformis

International Nuclear Information System (INIS)

Ramadan, A.A.; Ahmed, M.M.; Abo-state, M.A.M.; Sarhan, M.; Faroqe, M.

2007-01-01

Bacillus licheniformis is a gram positive spore forming bacterium. Different concentrations of cobalt affected the ability of Co uptake and growth of Bacillus licheniformis. As the concentration increased, both the uptake and growth were decreased. Maximum Co uptake was found at ph 7.0, while for growth was ph 8.0. The optimum temperature for uptake and growth was 40 degree C and 20% inoculum size represents the maximum cobalt uptake by Bacillus licheniformis. Also, maximum uptake was recorded after 72 hours, incubation period. As the concentration of cesium was increased till 400 mg/l, the uptake was also increased. The optimum cesium uptake and growth was at ph 8.0. The optimum growth was at 45 degree C while Cs uptake was found at 35 degree C and 15% inoculum size represented the maximum Cs uptake. After 72 hour incubation period, maximum Cs uptake was recorded. Generally, Bacillus licheniformis removed more than 80% of Co and 50% of Cs from the broth medium. Addition of clay to Bacillus licheniformis increased both Co or Cs uptake. Bacillus licheniformis was gamma resistant and 10 KGy reduced the viability by 5.3 log cycles. The irradiated and non-irradiated cultures can grow on 500 or 700 mg Co or Cs. Bacillus licheniformis removed 99.32% of the Co radionuclides and 99.28% of Cs radionuclides

Correlation between 5-Minute {sup 99m}Tc-Pertechnetate Uptake and 24-Hour {sup 131}I Uptake in Patients with Thyroid Disease

Energy Technology Data Exchange (ETDEWEB)

Lee, Chan Woo; Won, Kyu Chang; Yoon, Hyun Dae; Cho, In Ho; Kim, Tae Nyeun; Shin, Dong Gu; Lee, Hyoung Woo; Shim, Bong Sup; Lee, Hyun Woo [Yeungnam University School of Medicine, Daegu (Korea, Republic of)

1992-07-15

The 20-minute {sup 99m}Tc-pertechnetate uptake became readily available for routine use and it replaced {sup 131}I for thyroid imaging. However measuring thyroid uptake during a 5-minute minimizes pertechnetate uptake by the salivary glands and presence of contaminated saliva from those glands in to the pharynx and esophagus. A study was carried out to determine the suitability of the utility of a 5-minute and 20-minute interval from administration of {sup 99m}Tc-pertechnetate to imaging and uptake measurement as a replacement for the 24 hour standard originally established with {sup 131}I, and to evaluate the relationship between 5-minute {sup 99m}Tc-pertechnetate uptake and other thyroid functions. A 5-minute and 20-minute uptake of {sup 99m}Tc-pertechnetate were measured in 70 patients with thyroid disease at Yeungnam University Hospital from March 1, 1991 to Feb. 29, 1992. The results were as follows. 1) The 5-minute {sup 99m}Tc-pertechnetate uptake in Graves' disease, Hashimoto's thyroiditis, simple goiter non toxic nodular goiter, subacute thyroiditis and euthyroid were 18.2%, 14.6%, 2.8%, 3.2%, 1.2% and 1.1%, respectively. There was a significant difference between the mean of the euthyroid group and the mean of the Graves' disease. So differentiation between them can be easily made. 2) The 5 minute {sup 99m}Tc- pertechnetate thyroid uptake was well correlated with 24 hour {sup 131}I thyroid uptake (r=0.75, p<0.001). These data provided an equation for estimating the 24 hour uptake of iodide given the 5 minute pertechnetate uptake: Estimated 24-hour '1{sup 31}I thyroid Uptake = 7.188{sup *}In (5 minute {sup 99m}Tc-Pertechnetate uptake)+16.94 3) The 20-minute {sup 99m}Tc-pertechnetate thyroid uptake was well correlated with 24-hour {sup 131}I uptake (r=0.72, p<0.001) and 5-minute {sup 99m}Tc-pertechnetate thyroid uptake (r=0.96, p<0.001). 4) In the Graves' disease, The 5-minute {sup 99m}Tc-pertechnetate thyroid uptake was well

Uranium uptake of Vetiveria zizanioides (L.) Nash

International Nuclear Information System (INIS)

Luu Viet Hung; Maslov, O.D.; Trinh Thi Thu My; Phung Khac Nam Ho; Dang Duc Nhan

2010-01-01

Uranium uptake of vetiver grass (Vetiveria zizanioides (L.) Nash) from Eutric Fluvisols (AK), Albic Acrisols (BG), Dystric Fluvisols (HP) and Ferralic Acrisols (TC) in northern Vietnam is assessed. The soils were mixed with aqueous solution of uranyl nitrate to make soils contaminated with uranium at 0, 50, 100, 250 mg/kg before planting the grass. The efficiency of uranium uptake by the grass was assessed based on the soil-to-plant transfer factor (TF U , kg·kg -1 ). It was found that the TF U values are dependent upon the soils properties. CEC facilitates the uptake and the increased soil pH could reduce the uptake and translocation of uranium in the plant. Organic matter content, as well as iron and potassium, inhibits the uranium uptake of the grass. It was revealed that the lower fertile soil, the higher uranium uptake. The translocation of uranium in root for all the soil types studied is almost higher than that in its shoot. It seems that vetiver grass could potentially be used for the purpose of phytoremediation of soils contaminated with uranium

Monocyte transferrin-iron uptake in hereditary hemochromatosis

International Nuclear Information System (INIS)

Sizemore, D.J.; Bassett, M.L.

1984-01-01

Transferrin-iron uptake by peripheral blood monocytes was studied in vitro to test the hypothesis that the relative paucity of mononuclear phagocyte iron loading in hereditary hemochromatosis results from a defect in uptake of iron from transferrin. Monocytes from nine control subjects and 17 patients with hemochromatosis were cultured in the presence of 59Fe-labelled human transferrin. There was no difference in 59Fe uptake between monocytes from control subjects and monocytes from patients with hemochromatosis who had been treated by phlebotomy and who had normal body iron stores. However, 59Fe uptake by monocytes from iron-loaded patients with hemochromatosis was significantly reduced compared with either control subjects or treated hemochromatosis patients. It is likely that this was a secondary effect of iron loading since iron uptake by monocytes from treated hemochromatosis patients was normal. Assuming that monocytes in culture reflect mononuclear phagocyte iron metabolism in vivo, this study suggests that the relative paucity of mononuclear phagocyte iron loading in hemochromatosis is not related to an abnormality in transferrin-iron uptake by these cells

Up-regulation of serotonergic binding sites labeled by (3H) WB4101 following fimbrial transection and 5,7-dihydroxytryptamine-induced lesions

International Nuclear Information System (INIS)

Morrow, A.L.; Norman, A.B.; Battaglia, G.; Loy, R.; Creese, I.

1985-01-01

Lesions of the serotonergic afferents to the hippocampus, by fimbrial transection or by 5,7-dihydroxytryptamine treatment, produce an increase in the Bmax of ( 3 H)WB4101 to its nanomolar affinity binding site, with no effect on its picomolar affinity binding site or on ( 3 H)prazosin binding. The nanomolar site is serotonergic as the serotonergic agonists, serotonin and 8-hydroxy-dipropylaminotetraline (8-OH-DPAT) have nanomolar affinity for ( 3 H)WB4101 binding when studied in the presence of a prazosin mask (30nM) of the alpha-1 component of ( 3 H)WB4101 binding. The serotonin receptor antagonists metergoline, lysergic acid diethylamide and lisuride also have high nanomolar affinities while ketanserin, yohimbine, prazosin and noradrenergic agonists have affinities in the micromolar range. Fimbrial transection or 5,7-dihydroxytryptamine injections produced 32% and 44% increases in the Bmax of ( 3 H)WB4101 binding in the presence of a prazosin mask. Serotonin competition for ( 3 H)WB4101 binding was identical in control and experimental tissues from each lesion experiment. Although specific binding of ( 3 H)WB4101 was increased, there was no change in the affinities or the percentages of the two binding components for serotonin competition with ( 3 H)WB4101. These data suggest that removal of the serotonergic input to the hippocampus produces an increase in the Bmax of serotonin receptor binding sites labeled by ( 3 H)WB4101. 33 references, 3 figures, 3 tables

Low transient storage and uptake efficiencies in seven agricultural streams: implications for nutrient demand.

Science.gov (United States)

Sheibley, Richard W; Duff, John H; Tesoriero, Anthony J

2014-11-01

We used mass load budgets, transient storage modeling, and nutrient spiraling metrics to characterize nitrate (NO), ammonium (NH), and inorganic phosphorus (SRP) demand in seven agricultural streams across the United States and to identify in-stream services that may control these conditions. Retention of one or all nutrients was observed in all but one stream, but demand for all nutrients was low relative to the mass in transport. Transient storage metrics (/, , , and ) correlated with NO retention but not NH or SRP retention, suggesting in-stream services associated with transient storage and stream water residence time could influence reach-scale NO demand. However, because the fraction of median reach-scale travel time due to transient storage () was ≤1.2% across the sites, only a relatively small demand for NO could be generated by transient storage. In contrast, net uptake of nutrients from the water column calculated from nutrient spiraling metrics were not significant at any site because uptake lengths calculated from background nutrient concentrations were statistically insignificant and therefore much longer than the study reaches. These results suggest that low transient storage coupled with high surface water NO inputs have resulted in uptake efficiencies that are not sufficient to offset groundwater inputs of N. Nutrient retention has been linked to physical and hydrogeologic elements that drive flow through transient storage areas where residence time and biotic contact are maximized; however, our findings indicate that similar mechanisms are unable to generate a significant nutrient demand in these streams relative to the loads. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Hg uptake in ureteral obstructions

International Nuclear Information System (INIS)

Desgrez, J.P.; Bourguignon, M.; Raynaud, C.; CEA, 91 - Orsay

1976-01-01

In the presence of a total obstruction the results obtained with the Hg uptake test, as indeed with other functional tests, inform on the value of the kidney function at the time but have no prognostic value where repair possibilities are concerned. Some preliminary results seem to show however that very soon after the obstacle is removed, by the 10th or 15th day perhaps, quantitative functional tests may once more be used to evaluate the functional prognosis. This would mean that by waiting about two weeks after the disappearance of a total obstruction the Hg uptake test may again be used in all confidence. In order to check this deduction, which is based on slender evidence but which nevertheless has important practical implications, the measurement of the Hg uptake rate during the days following removal of the obstacle appears essential. In long-standing partial obstructions the Hg uptake rate gives an accurate assessment of the functional balance and helps considerably in the choice of therapy [fr

Ocean carbon uptake and storage

International Nuclear Information System (INIS)

Tilbrook, Bronte

2007-01-01

Full text: The ocean contains about 95% of the carbon in the atmosphere, ocean and land biosphere system, and is of fundamental importance in regulating atmospheric carbon dioxide concentrations. In the 1990s an international research effort involving Australia was established to determine the uptake and storage of anthropogenic C02 for all major ocean basins. The research showed that about 118 of the 244 + 20 billion tons of the anthropogenic carbon emitted through fossil fuel burning and cement production has been stored in the ocean since preindustrial times, thus helping reduce the rate of increase in atmospheric C02. The research also showed the terrestrial biosphere has been a small net source of C02 (39 ± 28 billion tons carbon) to the atmosphere over the same period. About 60% of the total ocean inventory of the anthropogenic C02 was found in the Southern Hemisphere, with most in the 30 0 S to 50 0 S latitude band. This mid-latitude band is where surface waters are subducted as Mode and Intermediate waters, which is a major pathway controlling ocean C02 uptake. High storage (23% of the total) also occurs in the North Atlantic, associated with deep water formation in that basin. The ocean uptake and storage is expected to increase in the coming decades as atmospheric C02 concentrations rise. However, a number of feedback mechanisms associated with surface warming, changes in circulation, and biological effects are likely to impact on the uptake capacity. The accumulation or storage-of the C02 in the ocean is also the major driver of ocean acidification with potential to disrupt marine ecosystems. This talk will describe the current understanding of the ocean C02 uptake and storage and a new international research strategy to detect how the ocean uptake and storage will evolve on interannual through decadal scales. Understanding the ocean response to increasing atmospheric C02 will be a key element in managing future C02 increases and establishing

18F-FDG uptake in the colon is modulated by metformin but not associated with core body temperature and energy expenditure.

Directory of Open Access Journals (Sweden)

Lonneke Bahler

Full Text Available Physiological colonic 18F-fluorodeoxyglucose (18F-FDG uptake is a frequent finding on 18F-FDG positron emission tomography computed tomography (PET-CT. Interestingly, metformin, a glucose lowering drug associated with moderate weight loss, is also associated with an increased colonic 18F-FDG uptake. Consequently, increased colonic glucose use might partly explain the weight losing effect of metformin when this results in an increased energy expenditure and/or core body temperature. Therefore, we aimed to determine whether metformin modifies the metabolic activity of the colon by increasing glucose uptake.In this open label, non-randomized, prospective mechanistic study, we included eight lean and eight overweight males. We measured colonic 18F-FDG uptake on PET-CT, energy expenditure and core body temperature before and after the use of metformin. The maximal colonic 18F-FDG uptake was measured in 5 separate segments (caecum, colon ascendens,-transversum,-descendens and sigmoid.The maximal colonic 18F-FDG uptake increased significantly in all separate segments after the use of metformin. There was no significant difference in energy expenditure or core body temperature after the use of metformin. There was no correlation between maximal colonic 18F-FDG uptake and energy expenditure or core body temperature.Metformin significantly increases colonic 18F-FDG uptake, but this increased uptake is not associated with an increase in energy expenditure or core body temperature. Although the colon might be an important site of the glucose plasma lowering actions of metformin, this mechanism of action does not explain directly any associated weight loss.

Factors affecting ¹⁸F FDOPA standardized uptake value in patients with primary brain tumors after treatment.

Science.gov (United States)

Chiaravalloti, Agostino; Fiorentini, Alessandro; Villani, Veronica; Carapella, Carmine; Pace, Andrea; Di Pietro, Barbara; Di Russo, Carmen; Palumbo, Barbara; Floris, Roberto; Schillaci, Orazio

2015-04-01

To investigate the factors affecting (18)F FDOPA uptake in patients with primary brain tumors (PBT) after treatment. 97 patients with PBT (6 were grade I, 40 were grade II, 29 were grade III and 22 were grade IV) underwent (18)F FDOPA positron emission tomography/computed tomography (PET/CT) after treatment. Intervals from surgery, chemotherapy (CHT) and radiotherapy (RT) were 41.48 (±42.27), 16.04 (±29.08) and 28.62 (±34.49) months respectively. (18)F FDOPA uptake in the site of recurrence was not related to the interval from surgery and CHT while a significant relationship has been found with the interval from RT and tumor grade. The results of our study show that the interval from RT and the grade of PBT should be considered carefully when evaluating brain PET/CT scans since these factors could directly affect (18)F FDOPA uptake. Copyright © 2015 Elsevier Inc. All rights reserved.

N-isopropyl-[123I]p-iodoamphetamine: single-pass brain uptake and washout; binding to brain synaptosomes; and localization in dog and monkey brain

International Nuclear Information System (INIS)

Winchell, H.S.; Horst, W.D.; Braun, L.; Oldendorf, W.H.; Hattner, R.; Parker, H.

1980-01-01

The kinetics of N-isopropyl-p-[ 123 I]iodoamphetamine in rat brains were determined by serial measurements of brain uptake index (BUI) after intracarotid injection; also studied were its effects on amine uptake and release in rat's brain cortical synaptosomes; and its in vivo distribution in the dog and monkey. No specific localization in brain nuclei of the dog was seen, but there was progressive accumulation in the eyes. Rapid initial brain uptake in the ketamine-sedated monkey was noted, and further slow brain uptake occurred during the next 20 min but without retinal localization. High levels of brain activity were maintained for several hours. The quantitative initial single-pass clearance of the agent in the brain suggests its use in evaluation of regional brain perfusion. Its interaction with brain amine-binding sites suggests its possible application in studies of cerebral amine metabolism

Does the intensity of diffuse thyroid gland uptake on F-18 fluorodeoxyglucose positron emission tomography/computed tomography scan predict the severity of hypothyroidism? Correlation between maximal standardized uptake value and serum thyroid stimulating hormone levels

International Nuclear Information System (INIS)

Pruthi, Ankur; Choudhury, Partha Sarathi; Gupta, Manoj; Taywade, Sameer

2015-01-01

F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) scan and hypothyroidism. The aim was to determine whether the intensity of diffuse thyroid gland uptake on F-18 FDG PET/CT scans predicts the severity of hypothyroidism. A retrospective analysis of 3868 patients who underwent F-18 FDG PET/CT scans, between October 2012 and June 2013 in our institution for various oncological indications was done. Out of them, 106 (2.7%) patients (79 females, 27 males) presented with bilateral diffuse thyroid gland uptake as an incidental finding. These patients were investigated retrospectively and various parameters such as age, sex, primary cancer site, maximal standardized uptake value (SUVmax), results of thyroid function tests (TFTs) and fine-needle aspiration cytology results were noted. The SUVmax values were correlated with serum thyroid stimulating hormone (S. TSH) levels using Pearson's correlation analysis. Pearson's correlation analysis. Clinical information and TFT (serum FT3, FT4 and TSH levels) results were available for 31 of the 106 patients (27 females, 4 males; mean age 51.5 years). Twenty-six out of 31 patients (84%) were having abnormal TFTs with abnormal TSH levels in 24/31 patients (mean S. TSH: 22.35 μIU/ml, median: 7.37 μIU/ml, range: 0.074-211 μIU/ml). Among 7 patients with normal TSH levels, 2 patients demonstrated low FT3 and FT4 levels. No significant correlation was found between maximum standardized uptake value and TSH levels (r = 0.115, P > 0.05). Incidentally detected diffuse thyroid gland uptake on F-18 FDG PET/CT scan was usually associated with hypothyroidism probably caused by autoimmune thyroiditis. Patients should be investigated promptly irrespective of the intensity of FDG uptake with TFTs to initiate replacement therapy and a USG examination to look for any suspicious nodules

Prediction of phenanthrene uptake by plants with a partition-limited model

International Nuclear Information System (INIS)

Zhu, Lizhong; Gao, Yanzheng

2004-01-01

The performance of a partition-limited model on prediction of phenanthrene uptake by a wide variety of plant species was evaluated using a greenhouse study. The model predictions of root or shoot concentrations for tested plant species were all within an order of magnitude of the observed values. Modeled root concentrations appeared to be more accurate than modeled shoot concentrations. The differences of simulated and experimented concentrations of phenanthrene in roots and shoots of three representative plant species, including ryegrass, flowering Chinese cabbage, and three-colored amaranth, were less than 81% for roots and 103% for shoots. Results are promising in that the α pt values of the partition-limited model for root uptake of phenanthrene correlate well with root lipid contents. Additionally, a significantly positive correlation is also observed between root concentration factors (RCFs, defined as the ratio of contaminant concentrations in root and in soil on a dry weight basis) of phenanthrene and root lipid contents. Results from this study suggest that the partition-limited model may have potential applications for predicting the plant PAH concentration in contaminated sites

Waterborne Release Monitoring and Surveillance Programs at the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Blanchard, A.

1999-03-26

This report documents the liquid release environmental compliance programs currently in place at the Savannah river Site (SRS). Included are descriptions of stream monitoring programs, which measure chemical parameters and radionuclides in site streams and the Savannah river and test representative biological communities within the streams for chemical and radiological uptake. This report also explains the field sampling and analytical capabilities that are available at SRS during both normal and emergency conditions.

Waterborne Release Monitoring and Surveillance Programs at the Savannah River Site

International Nuclear Information System (INIS)

Blanchard, A.

1999-01-01

This report documents the liquid release environmental compliance programs currently in place at the Savannah river Site (SRS). Included are descriptions of stream monitoring programs, which measure chemical parameters and radionuclides in site streams and the Savannah river and test representative biological communities within the streams for chemical and radiological uptake. This report also explains the field sampling and analytical capabilities that are available at SRS during both normal and emergency conditions

Cytotoxicity and cellular uptake of different sized gold nanoparticles in ovarian cancer cells

Science.gov (United States)

Kumar, Dhiraj; Mutreja, Isha; Chitcholtan, Kenny; Sykes, Peter

2017-11-01

Nanomedicine has advanced the biomedical field with the availability of multifunctional nanoparticles (NPs) systems that can target a disease site enabling drug delivery and helping to monitor the disease. In this paper, we synthesised the gold nanoparticles (AuNPs) with an average size 18, 40, 60 and 80 nm, and studied the effect of nanoparticles size, concentration and incubation time on ovarian cancer cells namely, OVCAR5, OVCAR8, and SKOV3. The size measured by transmission electron microscopy images was slightly smaller than the hydrodynamic diameter; measured size by ImageJ as 14.55, 38.13, 56.88 and 78.56 nm. The cellular uptake was significantly controlled by the AuNPs size, concentration, and the cell type. The nanoparticles uptake increased with increasing concentration, and 18 and 80 nm AuNPs showed higher uptake ranging from 1.3 to 5.4 μg depending upon the concentration and cell type. The AuNPs were associated with a temporary reduction in metabolic activity, but metabolic activity remained more than 60% for all sample types; NPs significantly affected the cell proliferation activity in first 12 h. The increase in nanoparticle size and concentration induced the production of reactive oxygen species in 24 h.

P-32 uptake in lentic algae

International Nuclear Information System (INIS)

Strange, J.R.; Williamson, G.D.; Fletcher, D.J.

1975-01-01

A study of the Flat Creek Embayment of Lake Sidney Lanier near Gainesville, Georgia revealed three genera of algae, Chlorococcum, Fragillaria and Nostoc, to be prominent in this eutrophic region of the lake. The algae was grown in phosphate-rich media and subsequently labelled with P-32. All species incorporated luxury amounts of phosphorus as determined by the uptake of P-32. The results indicate that the P-32 uptake is proportional to the surface-per-volume ratio. The higher surface-per-volume ratio resulted in greater uptake of P-32

Citrate and succinate uptake by potato mitochondria

International Nuclear Information System (INIS)

Jung, D.W.; Laties, G.G.

1979-01-01

Potato mitochondria, in the absence of respiration, have a very low capacity for uptake by exchange with endogenous anions, taking up only 2.4 nanomoles citrate and 2.0 nanomoles succinate per milligram protein. Maximum citrate uptake of over 17 nanomoles per milligram protein occurs in the presence of inorganic phosphate, a dicarboxylic acid, and an external energy source (NADH), conditions where net anion accumulation proceeds, mediated by the interlinking of the inorganic phosphate, dicarboxylate, and tricarboxylate carriers. Maximum succinate uptake in the absence of respiratory inhibitors requires only added inorganic phosphate. Compounds which inhibit respiration (antimycin), the exchange carriers (mersalyl and benzylmalonate), or the establishment of the membrane proton motive force (uncouplers) reduce substrate accumulation. A potent inhibitor of the citrate carrier in animal mitochondria, 1,2,3-benzenetricarboxylic acid, does not inhibit citrate uptake in potato mitochondria. Citrate uptake is reduced by concurrent ADP phosphorylation and this reduction is sensitive to oligomycin. The initiation of state 3 after a 3-minute substrate state results in a reduction of the steady-state of citrate uptake by approximately 50%. Accumulation of succinate initially is inhibited by increasing sucrose concentration in the reaction medium from 50 to 400 millimolar. Limited substrate uptake is one of the factors responsible for the often observed depressed initial state 3 respiration rates in many mitochondrial preparations. Since nonlimiting levels of substrate in the matrix cannot be attained by energy-independent exchange, a dependence on respiration for adequate uptake results. Substrate limitation therefore occurs in the matrix for the period of time needed for energy-dependent accumulation of nonlimiting levels

Plutonium uptake by marine phytoplankton in culture

International Nuclear Information System (INIS)

Fisher, N.S.; Olson, B.L.; Bowen, V.T.

1980-01-01

At environmentally realistic atom concentrations 237 Pu tracer was used to examine Pu uptake by unialgla cultures of Thalassiosira pseudonana (live and dead), Thalassiosira sp., and Platymonas sp., as well as by glass particles. Live or dead cells and glass particles accumulated Pu at similar rates, indicating that initial uptake was a passive phenomenon. Uptake was strongly affected by the nature of particle surfaces, but much less by composition of the media. Cells from rapidly growing cultures took up more Pu, than did those from late log or senescent cultures. Acid-washed glass took up more Pu, faster, than did unwashed glass. Cells accumulated more Pu from uv-treated seawater than from seawater untreated or enriched with f/50-level EDTA or f/50 vitamins; from complete f/50 medium uptake was even less, as with f/50 trace metals + EDTA. After a shot uptake Pu was 25% removable in tracer-free media, but after 3 days of uptake none was removable in seawater or exometabolite media, and only 15% in f/50-level EDTA. The data support the hypothesis that Pu in marine environments associates with suspended particles that could act as vertical vectors for this element

Uptake of gaseous formaldehyde onto soil surfaces: a coated-wall flow tube study

Science.gov (United States)

Li, Guo; Su, Hang; Li, Xin; Meusel, Hannah; Kuhn, Uwe; Pöschl, Ulrich; Shao, Min; Cheng, Yafang

2015-04-01

Gaseous formaldehyde (HCHO) is an important intermediate molecule and source of HO2 radicals. However, discrepancies exist between model simulated and observed HCHO concentrations, suggesting missing sources or sinks in the HCHO budget. Multiphase processes on the surface of soil and airborne soil-derived particles have been suggested as an important mechanism for the production/removal of atmospheric trace gases and aerosols. In this work, the uptake of gaseous HCHO on soil surfaces were investigated through coated-wall flow tube experiments with HCHO concentration ranging from 10 to 40 ppbv. The results show that the adsorption of HCHO occurred on soil surfaces, and the uptake coefficient dropped gradually (i.e., by a factor of 5 after 1 hour) as the reactive surface sites were consumed. The HCHO uptake coefficient was found to be affected by the relative humidity (RH), decreasing from (2.4 ± 0.5) × 10-4 at 0% RH to (3.0 ± 0.08) × 10-5 at 70% RH, due to competition of water molecule absorption on the soil surface. A release of HCHO from reacted soil was also detected by applying zero air, suggesting the nature of reversible physical absorption and the existence of an equilibrium at the soil-gas interface. It implies that soil could be either a source or a sink for HCHO, depending on the ambient HCHO concentration. We also develop a Matlab program to calculate the uptake coefficient under laminar flow conditions based on the Cooney-Kim-Davis method.

KCl stimulation increases norepinephrine transporter function in PC12 cells.

Science.gov (United States)

Mandela, Prashant; Ordway, Gregory A

2006-09-01

The norepinephrine transporter (NET) plays a pivotal role in terminating noradrenergic signaling and conserving norepinephrine (NE) through the process of re-uptake. Recent evidence suggests a close association between NE release and regulation of NET function. The present study evaluated the relationship between release and uptake, and the cellular mechanisms that govern these processes. KCl stimulation of PC12 cells robustly increased [3H]NE uptake via the NET and simultaneously increased [3H]NE release. KCl-stimulated increases in uptake and release were dependent on Ca2+. Treatment of cells with phorbol-12-myristate-13-acetate (PMA) or okadaic acid decreased [3H]NE uptake but did not block KCl-stimulated increases in [3H]NE uptake. In contrast, PMA increased [3H]NE release and augmented KCl-stimulated release, while okadaic acid had no effects on release. Inhibition of Ca2+-activated signaling cascades with KN93 (a Ca2+ calmodulin-dependent kinase inhibitor), or ML7 and ML9 (myosin light chain kinase inhibitors), reduced [3H]NE uptake and blocked KCl-stimulated increases in uptake. In contrast, KN93, ML7 and ML9 had no effect on KCl-stimulated [3H]NE release. KCl-stimulated increases in [3H]NE uptake were independent of transporter trafficking to the plasma membrane. While increases in both NE release and uptake mediated by KCl stimulation require Ca2+, different intracellular mechanisms mediate these two events.

Dibutyryl cyclic AMP induces differentiation of human neuroblastoma SH-SY5Y cells into a noradrenergic phenotype.

Science.gov (United States)

Kume, Toshiaki; Kawato, Yuka; Osakada, Fumitaka; Izumi, Yasuhiko; Katsuki, Hiroshi; Nakagawa, Takayuki; Kaneko, Shuji; Niidome, Tetsuhiro; Takada-Takatori, Yuki; Akaike, Akinori

2008-10-10

Dibutyryl cyclic AMP (dbcAMP) and retinoic acid (RA) have been demonstrated to be the inducers of morphological differentiation in SH-SY5Y cells, a human catecholaminergic neuroblastoma cell line. However, it remains unclear whether morphologically differentiated SH-SY5Y cells by these compounds acquire catecholaminergic properties. We focused on the alteration of tyrosine hydroxylase (TH) expression and intracellular content of noradrenaline (NA) as the indicators of functional differentiation. Three days treatment with dbcAMP (1mM) and RA (10microM) induced morphological changes and an increase of TH-positive cells using immunocytochemical analysis in SH-SY5Y cells. The percentage of TH-expressing cells in dbcAMP (1mM) treatment was larger than that in RA (10microM) treatment. In addition, dbcAMP increased intracellular NA content, whereas RA did not. The dbcAMP-induced increase in TH-expressing cells is partially inhibited by KT5720, a protein kinase A (PKA) inhibitor. We also investigated the effect of butyrate on SH-SY5Y cells, because dbcAMP is enzymatically degraded by intracellular esterase, thereby resulting in the formation of butyrate. Butyrate induced the increase of NA content at lower concentrations than dbcAMP, although the increase in TH-expressing cells by butyrate was smaller than that by dbcAMP. The dbcAMP (1mM)- and butyrate (0.3mM)-induced increase in NA content was completely suppressed by alpha-methyl-p-tyrosine (1mM), an inhibitor of TH. These results suggest that dbcAMP induces differentiation into the noradrenergic phenotype through both PKA activation and butyrate.

Metformin normalizes the structural changes in glycogen preceding prediabetes in mice overexpressing neuropeptide Y in noradrenergic neurons.

Science.gov (United States)

Ailanen, Liisa; Bezborodkina, Natalia N; Virtanen, Laura; Ruohonen, Suvi T; Malova, Anastasia V; Okovityi, Sergey V; Chistyakova, Elizaveta Y; Savontaus, Eriika

2018-04-01

Hepatic insulin resistance and increased gluconeogenesis are known therapeutic targets of metformin, but the role of hepatic glycogen in the pathogenesis of diabetes is less clear. Mouse model of neuropeptide Y (NPY) overexpression in noradrenergic neurons (OE-NPY D βH ) with a phenotype of late onset obesity, hepatosteatosis, and prediabetes was used to study early changes in glycogen structure and metabolism preceding prediabetes. Furthermore, the effect of the anti-hyperglycemic agent, metformin (300 mg/kg/day/4 weeks in drinking water), was assessed on changes in glycogen metabolism, body weight, fat mass, and glucose tolerance. Glycogen structure was characterized by cytofluorometric analysis in isolated hepatocytes and mRNA expression of key enzymes by qPCR. OE-NPY D βH mice displayed decreased labile glycogen fraction relative to stabile fraction (the intermediate form of glycogen) suggesting enhanced glycogen cycling. This was supported by decreased filling of glucose residues in the 10th outer tier of the glycogen molecule, which suggests accelerated glycogen phosphorylation. Metformin reduced fat mass gain in both genotypes, but glucose tolerance was improved mostly in wild-type mice. However, metformin inhibited glycogen accumulation and normalized the ratio between glycogen structures in OE-NPY D βH mice indicating decreased glycogen synthesis. Furthermore, the presence of glucose residues in the 11th tier together with decreased glycogen phosphorylase expression suggested inhibition of glycogen degradation. In conclusion, structural changes in glycogen of OE-NPY D βH mice point to increased glycogen metabolism, which may predispose them to prediabetes. Metformin treatment normalizes these changes and suppresses both glycogen synthesis and phosphorylation, which may contribute to its preventive effect on the onset of diabetes.

A home-school-doctor model to break the barriers for uptake of human papillomavirus vaccine.

Science.gov (United States)

Lee, Albert; Wong, Martin C S; Chan, Tracy T; Chan, Paul K S

2015-09-21

A high coverage of human papillomavirus (HPV) vaccination is required to achieve a clinically significant reduction in disease burden. Countries implementing free-of-charge national vaccination program for adolescent girls are still challenged by the sub-optimal uptake rate. Voluntary on-site school-based mass vaccination programs have demonstrated high coverage. Here, we tested whether this could be an option for countries without a government-supported vaccination program as in Hong Kong. A Home-School-Doctor model was evolved based on extensive literature review of various health promotion models together with studies on HPV vaccination among adolescent girls. The outcome measure was uptake of vaccination. Factors associated with the outcome were measured by validated surveys in which 4,631 students from 24 school territory wide participated. Chi-square test was used to analyze association between the categorical variables and the outcome. Multivariate analysis was performed to identify independent variables associated with the outcome with vaccine group as case and non-vaccine group as control. In multivariate analysis, parental perception of usefulness of the Home-School-Doctor model had a very high odds ratio for uptake of HPV vaccination (OR 26.6, 95% CI 16.4, 41.9). Paying a reasonable price was another independent factor associated with increased uptake (OR 1.71, 95% CI 1.39, 2.1 for those with parents willing to pay US$125-250 for vaccination). For parents and adolescents who were not sure where to get vaccination, this model was significantly associated with improved uptake rate (OR 1.66, 95% CI 1.23, 2.23). Concerns with side effects of vaccine (OR 0.70, 95% CI 0.55, 0.88), allowing daughters to make their own decisions (OR 0.49, 95% CI 0.38, 0.64) and not caring much about daughters' social life (95% CI 0.45, 0.92) were factors associated with a lower uptake. The findings of this study have added knowledge on how a school-based vaccination program

Branchial cadmium and copper binding and intestinal cadmium uptake in wild yellow perch (Perca flavescens) from clean and metal-contaminated lakes

International Nuclear Information System (INIS)

Klinck, J.S.; Green, W.W.; Mirza, R.S.; Nadella, S.R.; Chowdhury, M.J.; Wood, C.M.; Pyle, G.G.

2007-01-01

Branchial binding kinetics and gastro-intestinal uptake of copper and cadmium where examined in yellow perch (Perca flavescens) from a metal-contaminated lake (Hannah Lake, Sudbury, Ontario, Canada) and an uncontaminated lake (James Lake, North Bay, Ontario, Canada). An in vivo approach was taken for gill binding comparisons while an in vitro gut binding assay was employed for gastro-intestinal tract (GIT) uptake analysis. By investigating metal uptake at the gill and the gut we cover the two main routes of metal entry into fish. Comparisons of water and sediment chemistries, metal burdens in benthic invertebrate, and metal burdens in the livers of perch from the two study lakes clearly show that yellow perch from Hannah L. are chronically exposed to a highly metal-contaminated environment compared to a reference lake. We found that metal-contaminated yellow perch showed no significant difference in gill Cd binding compared to reference fish, but they did show significant decreases in new Cd binding and absorption in their GITs. The results show that gill Cd binding may involve low-capacity, high-affinity binding sites, while gastro-intestinal Cd uptake involves binding sites that are high-capacity, low-affinity. From this we infer that Cd may be more critically controlled at the gut rather than gills. Significant differences in branchial Cu binding (increased binding) were observed in metal-contaminated yellow perch. We suggest that chronic waterborne exposure to Cu (and/or other metals) may be the dominant influence in gill Cu binding rather than chronic exposure to high Cu diets. We give supporting evidence that Cd is taken up in the GIT, at least in part, by a similar pathway as Ca 2+ , principally that elevated dietary Ca 2+ reduces Cd binding and uptake. Overall our study reveals that metal pre-exposure via water and diet can alter uptake kinetics of Cu and Cd at the gill and/or the gut

Branchial cadmium and copper binding and intestinal cadmium uptake in wild yellow perch (Perca flavescens) from clean and metal-contaminated lakes

Energy Technology Data Exchange (ETDEWEB)

Klinck, J.S. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada)], E-mail: klinckjs@mcmaster.ca; Green, W.W.; Mirza, R.S. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada); Department of Biology, Nipissing University, North Bay, Ont. P1B 8L7 (Canada); Nadella, S.R.; Chowdhury, M.J.; Wood, C.M. [Department of Biology, McMaster University, Hamilton, Ont. L8S 4K1 (Canada); Pyle, G.G. [Department of Biology, Nipissing University, North Bay, Ont. P1B 8L7 (Canada)

2007-08-30

Branchial binding kinetics and gastro-intestinal uptake of copper and cadmium where examined in yellow perch (Perca flavescens) from a metal-contaminated lake (Hannah Lake, Sudbury, Ontario, Canada) and an uncontaminated lake (James Lake, North Bay, Ontario, Canada). An in vivo approach was taken for gill binding comparisons while an in vitro gut binding assay was employed for gastro-intestinal tract (GIT) uptake analysis. By investigating metal uptake at the gill and the gut we cover the two main routes of metal entry into fish. Comparisons of water and sediment chemistries, metal burdens in benthic invertebrate, and metal burdens in the livers of perch from the two study lakes clearly show that yellow perch from Hannah L. are chronically exposed to a highly metal-contaminated environment compared to a reference lake. We found that metal-contaminated yellow perch showed no significant difference in gill Cd binding compared to reference fish, but they did show significant decreases in new Cd binding and absorption in their GITs. The results show that gill Cd binding may involve low-capacity, high-affinity binding sites, while gastro-intestinal Cd uptake involves binding sites that are high-capacity, low-affinity. From this we infer that Cd may be more critically controlled at the gut rather than gills. Significant differences in branchial Cu binding (increased binding) were observed in metal-contaminated yellow perch. We suggest that chronic waterborne exposure to Cu (and/or other metals) may be the dominant influence in gill Cu binding rather than chronic exposure to high Cu diets. We give supporting evidence that Cd is taken up in the GIT, at least in part, by a similar pathway as Ca{sup 2+}, principally that elevated dietary Ca{sup 2+} reduces Cd binding and uptake. Overall our study reveals that metal pre-exposure via water and diet can alter uptake kinetics of Cu and Cd at the gill and/or the gut.

Electron uptake by iron-oxidizing phototrophic bacteria

Energy Technology Data Exchange (ETDEWEB)

Bose, A; Gardel, EJ; Vidoudez, C; Parra, EA; Girguis, PR

2014-02-26

Oxidation-reduction reactions underlie energy generation in nearly all life forms. Although most organisms use soluble oxidants and reductants, some microbes can access solid-phase materials as electron-acceptors or -donors via extracellular electron transfer. Many studies have focused on the reduction of solid-phase oxidants. Far less is known about electron uptake via microbial extracellular electron transfer, and almost nothing is known about the associated mechanisms. Here we show that the iron-oxidizing photoautotroph Rhodopseudomonas palustris TIE-1 accepts electrons from a poised electrode, with carbon dioxide as the sole carbon source/electron acceptor. Both electron uptake and ruBisCo form I expression are stimulated by light. Electron uptake also occurs in the dark, uncoupled from photosynthesis. Notably, the pioABC operon, which encodes a protein system essential for photoautotrophic growth by ferrous iron oxidation, influences electron uptake. These data reveal a previously unknown metabolic versatility of photoferrotrophs to use extracellular electron transfer for electron uptake.

Identification of residues of FpvA involved in the different steps of Pvd-Fe uptake in Pseudomonas aeruginosa.

Science.gov (United States)

Nader, Mirella; Dobbelaere, Wim; Vincent, Michel; Journet, Laure; Adams, Hendrik; Cobessi, David; Gallay, Jacques; Schalk, Isabelle J

2007-10-23

FpvA is an outer membrane transporter involved in iron uptake by the siderophore pyoverdine (Pvd) in Pseudomonas aeruginosa. This transporter, like all other proteins of the same family, consists of a transmembrane 22 beta-stranded barrel occluded by a plug domain. The beta-strands of the barrel are connected by large extracellular loops and short periplasmic turns. Site-directed mutagenesis was carried out on FpvA to identify the extracellular loops or parts of these loops involved in the various stages of Pvd-Fe uptake. The G286C, W362C, and W434C mutations in loops L1, L3, and L4, respectively, disturbed the binding of the apo siderophore, as shown by time-resolved fluorescence spectroscopy. Iron uptake experiments followed by fluorescence resonance energy transfer (FRET) or using 55Fe indicated that residues W434 and G701 and, therefore, loops L4 and L9 must be involved in Pvd-Fe uptake by FpvA. The two corresponding mutants incorporated smaller than normal amounts of 55Fe into cells, and no Pvd recycling on FpvA was observed after iron release. Surprisingly, the S603C mutation in loop L7 increased the amount of Pvd-Fe transported. Our results suggest that W434 (L4), S603 (L7), and G701 (L9) are involved in the mechanism of Pvd-Fe uptake.

18F-FDG uptake in the colon is modulated by metformin but not associated with core body temperature and energy expenditure

Science.gov (United States)

Bahler, Lonneke; Holleman, Frits; Chan, Man-Wai; Booij, Jan; Hoekstra, Joost B.; Verberne, Hein J.

2017-01-01

Purpose Physiological colonic 18F-fluorodeoxyglucose (18F-FDG) uptake is a frequent finding on 18F-FDG positron emission tomography computed tomography (PET-CT). Interestingly, metformin, a glucose lowering drug associated with moderate weight loss, is also associated with an increased colonic 18F-FDG uptake. Consequently, increased colonic glucose use might partly explain the weight losing effect of metformin when this results in an increased energy expenditure and/or core body temperature. Therefore, we aimed to determine whether metformin modifies the metabolic activity of the colon by increasing glucose uptake. Methods In this open label, non-randomized, prospective mechanistic study, we included eight lean and eight overweight males. We measured colonic 18F-FDG uptake on PET-CT, energy expenditure and core body temperature before and after the use of metformin. The maximal colonic 18F-FDG uptake was measured in 5 separate segments (caecum, colon ascendens,—transversum,—descendens and sigmoid). Results The maximal colonic 18F-FDG uptake increased significantly in all separate segments after the use of metformin. There was no significant difference in energy expenditure or core body temperature after the use of metformin. There was no correlation between maximal colonic 18F-FDG uptake and energy expenditure or core body temperature. Conclusion Metformin significantly increases colonic 18F-FDG uptake, but this increased uptake is not associated with an increase in energy expenditure or core body temperature. Although the colon might be an important site of the glucose plasma lowering actions of metformin, this mechanism of action does not explain directly any associated weight loss. PMID:28464031

CONSEXPO 3.0, consumer exposure and uptake models

NARCIS (Netherlands)

Veen MP van; LBM

2001-01-01

The report provides a modelling approach to consumer exposure to chemicals, based on mathematical contact, exposure and uptake models. For each route of exposure, a number of exposure and uptake models are included. A general framework joins the exposure and uptake models selected by the user. By

Dependence of FDG uptake on tumor microenvironment

International Nuclear Information System (INIS)

Pugachev, Andrei; Ruan, Shutian; Carlin, Sean; Larson, Steven M.; Campa, Jose; Ling, C. Clifton; Humm, John L.

2005-01-01

Purpose: To investigate the factors affecting the 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake in tumors at a microscopic level, by correlating it with tumor hypoxia, cellular proliferation, and blood perfusion. Methods and Materials: Nude mice bearing Dunning prostate tumors (R3327-AT) were injected with 18 F-FDG and pimonidazole, bromodeoxyuridine, and, 1 min before sacrifice, with Hoechst 33342. Selected tumor sections were imaged by phosphor plate autoradiography, while adjacent sections were used to obtain the images of the spatial distribution of Hoechst 33342, pimonidazole, and bromodeoxyuridine. The images were co-registered and analyzed on a pixel-by-pixel basis. Results: Statistical analysis of the data obtained from these tumors demonstrated that 18 F-FDG uptake was positively correlated with pimonidazole staining intensity in each data set studied. Correlation of FDG uptake with bromodeoxyuridine staining intensity was always negative. In addition, FDG uptake was always negatively correlated with the staining intensity of Hoechst 33342. Conclusions: For the Dunning prostate tumors studied, FDG uptake was always positively correlated with hypoxia and negatively correlated with both cellular proliferation and blood flow. Therefore, for the tumor model studied, higher FDG uptake is indicative of tumor hypoxia, but neither blood flow nor cellular proliferation

Observation of 99Tcm-MIBI uptake of ischemic myocardium in dog models after left circumflex coronary artery constriction

International Nuclear Information System (INIS)

Cheng Guanghua; Dai Yunhai; Wu Kefang; Xu Quanfeng

2008-01-01

Objective: To observe 99 Tc m -MIBI uptake of ischemic myocardium at different times (1h, 4h) in dog models after left circumflex coronary artery constriction. Methods: 12 dog models of coronary artery stenosis were prepared by left circumflex coronary ligation, and were given injection of 99 Tc m -MIBI at the dosage of 185 MBq (5 mCi). Six models were sacrificed at one hour and four hours after the injection respectively. Radio-uptake in about 100 mg myocardium from both ischemic and non-ischemic sites were measured with r-counter. Results: No significant differences were found between ratios of radioactive count of ischemic over normal myocardial tissues at 1h and 4h after injection of 99 Tc m -MIBI (0.726±0.054 and 0.673±0.080, respective, t=1.3452, P >0.05). Conclusion: The extension of post-injection time would not increase 99 Tc m -MIBI uptake in ischemic myocardium. (authors)

Localised uptake and extraction of Calcium/sup 45/ in dinoflagellate nuclei: An autoradiographic study

Energy Technology Data Exchange (ETDEWEB)

Sigee, D.C.

1983-01-01

The uptake of Ca/sup 45/ into cells of the dinoflagellate Glenodinium foliaceum was investigated using insoluble compound light microscope autoradiography. The distribution of silver grains showed marked localisation to the dinocaryotic nucleus, with a random scatter of grains over the surrounding protoplasm (cytoplasm and supernumerary nucleus). Correction of grain counts for lateral sensitisation from the dinocaryotic nucleus indicated an isotope concentration 16-32 times greater in this organelle compared to the rest of the cell. Cells labelled for varying periods of time showed differences in the pattern of Ca/sup 45/ uptake throughout the sample populations, but no increase in the mean level of uptake per cell. This would suggest a rapid incorporation of isotope within 1-2 hours, with little subsequent uptake. The presence of high levels of label after processing with both additive (glutaraldehyde, paraformaldehyde) and coagulative (acetic alcohol) fixatives indicated that the retention of Ca/sup 45/ in these preparations was not simply a fixation artefact. Although the isotope did not appear to be suitable for (high resolution) electron microscope autoradiography, the intranuclear site of incorporation was demonstrated indirectly using a buffer extraction technique. Prolonged treatment with phosphate buffer resulted in a large scale loss of label from both cytoplasm and dinocaryotic nucleus. The latter appeared to show specific correlation with the loss of (protein) matrix from the chromosomes - as observed under both light and electron microscopy, with no apparent change in either nucleolus or nucleoplasm. This would suggest that incorporated Ca/sup 45/ in the nucleus was largely confined to the condensed chromatin, where it was combined with the acidic proteins which make up the bulk of the chromatin matrix. The results obtained in this investigation are related to previous studies involving X-ray microanalysis and uptake of Ni/sup 63/.

Mechanisms of DNA uptake by cells

Energy Technology Data Exchange (ETDEWEB)

Lacks, S.A.

1977-01-01

Three categories of cellular uptake of DNA can be distinguished. First, in the highly transformable bacteria, such as Diplococcus pneumoniae, Haemophilus influenzae and Bacillus subtilis, elaborate mechanisms of DNA transport have evolved, presumably for the purpose of genetic exchange. These mechanisms can introduce substantial amounts of DNA into the cell. Second, methods have been devised for the forced introduction of DNA by manipulation of bacterial cells under nonphysiological conditions. By such means small but significant amounts of DNA have been introduced into various bacteria, including Escherichia coli. Third, mammalian cells are able to take up biologically active DNA. This has been most clearly demonstrated with viral DNA, although the mechanism of uptake is not well understood. The intention, here, is to survey current understanding of the various mechanisms of DNA uptake. A review of experience with the bacterial systems may throw some light on the mammalian system and lead to suggestions for enhancing DNA uptake by mammalian cells.

Short-term uptake of heavy metals by periphyton algae

Energy Technology Data Exchange (ETDEWEB)

Vymazal, J.

1984-12-31

The utilization of periphyton for the removal of heavy metals from enriched small streams has been examined. By means of short-term batch laboratory experiments the courses of metal uptake have been studied. For uptake study naturally growing periphyton community and periphytic filamentous algae Cladophora glomerata and Oedogonium rivulare have been used. Uptakes of nine heavy metals (Pb, Cd, Cu, Co, Cr, Ni, Zn, Fe and Mn) have been determined during four hours exposure. In addition the influence of humic substances on heavy metals uptake has been determined. Uptake of all metals increased during four hours exposure but not in the same way. Some metals were removed continuously (Ni, Cr, Fe and Mn), other metals were removed more rapidly during the first hour or first two hours of exposure and then only slight removal continued (Cu, Pb, Cd, Co). Uptake of Zn was rather unambiguous. Results of these experiments suggest that the course of uptake for individual metals could be similar for most periphyton algae. It was established that humic substances significantly reduce heavy metals uptake. The highest decrease of uptake was observed in Cu, Cr, Co and Cd. The results of model experiments are being tested in a pilot scale with respect to the demands of engineering practice. (J.R.)

Radiocesium (137Cs) uptake in mallards at the Savannah River Site (SRS) and effects on DNA cell cycle in red blood cells

International Nuclear Information System (INIS)

George, L.S.; Dallas, C.E.; Brisbin, I.L.; Evans, D.E.

1990-01-01

The objective of this study was to determine the rate and magnitude of uptake of 137 Cs in free-living mallards and assess possible correlations with alterations of the DNA cell cycle in red blood cells (rbc). Two sets of control mallards were maintained. One hundred ducks were released on a 137 Cs-contaminated pond at SRS, and whole body burdens measured periodically using gamma-spectroscopy. Blood samples were obtained from the mallards at intervals over the course of 1 year to determine if there was a change in the rbc cell cycle compared to the controls. DNA histograms depicting cell cycle percentages and coefficients of variations (CV) were obtained using flow cytometry. 137 Cs uptake in the ducks followed a sigmoidal curve. The most rapid phase of body burden increase occurred between 50-100 days. A steady-state was reached thereafter, with mean whole-body levels of levels of 56 pCi/g present at 102 days. Exposure-related changes in the CV and cell cycle pattern were observed during the rapid phase of 137 Cs uptake. DNA histograms from several of the contaminated ducks revealed aneuploid-like patterns in the rbc DNA after an exposure to 137 Cs of 9 months

Elevated uptake of plasma macromolecules by regions of arterial wall predisposed to plaque instability in a mouse model.

Directory of Open Access Journals (Sweden)

Zahra Mohri

Full Text Available Atherosclerosis may be triggered by an elevated net transport of lipid-carrying macromolecules from plasma into the arterial wall. We hypothesised that whether lesions are of the thin-cap fibroatheroma (TCFA type or are less fatty and more fibrous depends on the degree of elevation of transport, with greater uptake leading to the former. We further hypothesised that the degree of elevation can depend on haemodynamic wall shear stress characteristics and nitric oxide synthesis. Placing a tapered cuff around the carotid artery of apolipoprotein E -/- mice modifies patterns of shear stress and eNOS expression, and triggers lesion development at the upstream and downstream cuff margins; upstream but not downstream lesions resemble the TCFA. We measured wall uptake of a macromolecular tracer in the carotid artery of C57bl/6 mice after cuff placement. Uptake was elevated in the regions that develop lesions in hyperlipidaemic mice and was significantly more elevated where plaques of the TCFA type develop. Computational simulations and effects of reversing the cuff orientation indicated a role for solid as well as fluid mechanical stresses. Inhibiting NO synthesis abolished the difference in uptake between the upstream and downstream sites. The data support the hypothesis that excessively elevated wall uptake of plasma macromolecules initiates the development of the TCFA, suggest that such uptake can result from solid and fluid mechanical stresses, and are consistent with a role for NO synthesis. Modification of wall transport properties might form the basis of novel methods for reducing plaque rupture.

Skeletal muscle glucose uptake during dynamic exercise in humans

DEFF Research Database (Denmark)

Richter, Erik; Kiens, Bente; Saltin, Bengt

1988-01-01

uptake was not compensated for by increased uptake of free fatty acids but was accompanied by decreases in plasma insulin and increases in plasma epinephrine and norepinephrine. During work with large muscle masses, arterial lactate increased to approximately 6 mM, and net leg lactate release reverted......To study the role of muscle mass in glucoregulation, six subjects worked with the knee extensors of one leg on a specially constructed cycle ergometer. The knee extensors of one leg worked either alone or in combination with the knee extensors of the other leg and/or with the arms. Substrate usage...... to net lactate uptake. Decreased glucose uptake could not be explained by decreased perfusion. It is concluded that thigh muscle glucose uptake is affected by the size of the total muscle mass engaged in exercise. The decrease in thigh glucose uptake, when arm cranking was added and O2 uptake...

Changes in soil moisture drive soil methane uptake along a fire regeneration chronosequence in a eucalypt forest landscape.

Science.gov (United States)

Fest, Benedikt; Wardlaw, Tim; Livesley, Stephen J; Duff, Thomas J; Arndt, Stefan K

2015-11-01

Disturbance associated with severe wildfires (WF) and WF simulating harvest operations can potentially alter soil methane (CH4 ) oxidation in well-aerated forest soils due to the effect on soil properties linked to diffusivity, methanotrophic activity or changes in methanotrophic bacterial community structure. However, changes in soil CH4 flux related to such disturbances are still rarely studied even though WF frequency is predicted to increase as a consequence of global climate change. We measured in-situ soil-atmosphere CH4 exchange along a wet sclerophyll eucalypt forest regeneration chronosequence in Tasmania, Australia, where the time since the last severe fire or harvesting disturbance ranged from 9 to >200 years. On all sampling occasions, mean CH4 uptake increased from most recently disturbed sites (9 year) to sites at stand 'maturity' (44 and 76 years). In stands >76 years since disturbance, we observed a decrease in soil CH4 uptake. A similar age dependency of potential CH4 oxidation for three soil layers (0.0-0.05, 0.05-0.10, 0.10-0.15 m) could be observed on incubated soils under controlled laboratory conditions. The differences in soil CH4 uptake between forest stands of different age were predominantly driven by differences in soil moisture status, which affected the diffusion of atmospheric CH4 into the soil. The observed soil moisture pattern was likely driven by changes in interception or evapotranspiration with forest age, which have been well described for similar eucalypt forest systems in south-eastern Australia. Our results imply that there is a large amount of variability in CH4 uptake at a landscape scale that can be attributed to stand age and soil moisture differences. An increase in severe WF frequency in response to climate change could potentially increase overall forest soil CH4 sinks. © 2015 John Wiley & Sons Ltd.

Evaluation of hilar 67Ga-citrate uptake in bronchogenic carcinoma

International Nuclear Information System (INIS)

Matsuno, Noriyo; Kuyama, Junpei; Uchida, Yoshitaka; Hatano, Osamu; Imai, Yasunori; Uno, Kimiichi; Minoshima, Satoshi.

1995-01-01

We evaluated hilar uptake on 67 Ga-citrate scintigraphy and correlated with hilar lymph node metastases in one-hundred seventeen cases (two-hundred thirty four hila) of bronchogenic carcinoma. Hilar uptake was classified into three grades independently on anterior and posterior chest views: no uptake (grade 0), uptake equal to that in the thoracic vertebrae (grade 1), and uptake higher than that in the thoracic vertebrae (grade 2). If a summed grade of anterior and posterior view was larger than 3, hilar uptake was considered as positive. In forty-four cases (forty-nine hila) with hilar lymph node metastases, positive hilar uptake was found in ten cases (eleven hila), resulting in sensitivity of 22% based on cases and 23% based on hila. In seventy-three cases (one-hundred forty-six hila) without hilar lymph node metastases, positive hilar uptake was found in six cases (ten hila), resulting in specificity of 91% based on cases and 93% based on hila. In comparison to scintigraphic findings of unilaterally positive hilar uptake, findings of bilaterally positive hilar uptake showed significantly lower accuracy in determining presence of hilar lymph node metastases. No definite correlation between hilar uptake and histopathology or 67 Ga-citrate uptake in a primary tumor was observed. The results indicate that usefulness of 67 Ga-citrate scintigraphy is limited when evaluating hilar lymph node metastases in bronchogenic carcinoma. (author)

A biophysical approach using water deficit factor for daily estimations of evapotranspiration and CO2 uptake in Mediterranean environments

Science.gov (United States)

Helman, David; Lensky, Itamar M.; Osem, Yagil; Rohatyn, Shani; Rotenberg, Eyal; Yakir, Dan

2017-09-01

Estimations of ecosystem-level evapotranspiration (ET) and CO2 uptake in water-limited environments are scarce and scaling up ground-level measurements is not straightforward. A biophysical approach using remote sensing (RS) and meteorological data (RS-Met) is adjusted to extreme high-energy water-limited Mediterranean ecosystems that suffer from continuous stress conditions to provide daily estimations of ET and CO2 uptake (measured as gross primary production, GPP) at a spatial resolution of 250 m. The RS-Met was adjusted using a seasonal water deficit factor (fWD) based on daily rainfall, temperature and radiation data. We validated our adjusted RS-Met with eddy covariance flux measurements using a newly developed mobile lab system and the single active FLUXNET station operating in this region (Yatir pine forest station) at a total of seven forest and non-forest sites across a climatic transect in Israel (280-770 mm yr-1). RS-Met was also compared to the satellite-borne MODIS-based ET and GPP products (MOD16 and MOD17, respectively) at these sites.Results show that the inclusion of the fWD significantly improved the model, with R = 0.64-0.91 for the ET-adjusted model (compared to 0.05-0.80 for the unadjusted model) and R = 0.72-0.92 for the adjusted GPP model (compared to R = 0.56-0.90 of the non-adjusted model). The RS-Met (with the fWD) successfully tracked observed changes in ET and GPP between dry and wet seasons across the sites. ET and GPP estimates from the adjusted RS-Met also agreed well with eddy covariance estimates on an annual timescale at the FLUXNET station of Yatir (266 ± 61 vs. 257 ± 58 mm yr-1 and 765 ± 112 vs. 748 ± 124 gC m-2 yr-1 for ET and GPP, respectively). Comparison with MODIS products showed consistently lower estimates from the MODIS-based models, particularly at the forest sites. Using the adjusted RS-Met, we show that afforestation significantly increased the water use efficiency (the ratio of carbon uptake to ET) in this region

Capturing Individual Uptake: Toward a Disruptive Research Methodology

Science.gov (United States)

Bastian, Heather

2015-01-01

This article presents and illustrates a qualitative research methodology for studies of uptake. It does so by articulating a theoretical framework for qualitative investigations of uptake and detailing a research study designed to invoke and capture students' uptakes in a first-year writing classroom. The research design sought to make uptake…

Contributions of the Nucleus Accumbens Shell in Mediating the Enhancement in Memory Following Noradrenergic Activation of Either the Amygdala or Hippocampus

Directory of Open Access Journals (Sweden)

Erin C. Kerfoot

2018-02-01

Full Text Available The nucleus accumbens shell is a site of converging inputs during memory processing for emotional events. The accumbens receives input from the nucleus of the solitary tract (NTS regarding changes in peripheral autonomic functioning following emotional arousal. The shell also receives input from the amygdala and hippocampus regarding affective and contextual attributes of new learning experiences. The successful encoding of affect or context is facilitated by activating noradrenergic systems in either the amygdala or hippocampus. Recent findings indicate that memory enhancement produced by activating NTS neurons, is attenuated by suppressing accumbens functioning after learning. This finding illustrates the significance of the shell in integrating information from the periphery to modulate memory for arousing events. However, it is not known if the accumbens shell plays an equally important role in consolidating information that is initially processed in the amygdala and hippocampus. The present study determined if the convergence of inputs from these limbic regions within the nucleus accumbens contributes to successful encoding of emotional events into memory. Male Sprague-Dawley rats received bilateral cannula implants 2 mm above the accumbens shell and a second bilateral implant 2 mm above either the amygdala or hippocampus. The subjects were trained for 6 days to drink from a water spout. On day 7, a 0.35 mA footshock was initiated as the rat approached the spout and was terminated once the rat escaped into a white compartment. Subjects were then given intra-amygdala or hippocampal infusions of PBS or a dose of norepinephrine (0.2 μg previously shown to enhance memory. Later, all subjects were given intra-accumbens infusion of muscimol to functionally inactivate the shell. Muscimol inactivation of the accumbens shell was delayed to allow sufficient time for norepinephrine to activate intracellular cascades that lead to long-term synaptic

Contributions of the Nucleus Accumbens Shell in Mediating the Enhancement in Memory Following Noradrenergic Activation of Either the Amygdala or Hippocampus.

Science.gov (United States)

Kerfoot, Erin C; Williams, Cedric L

2018-01-01

The nucleus accumbens shell is a site of converging inputs during memory processing for emotional events. The accumbens receives input from the nucleus of the solitary tract (NTS) regarding changes in peripheral autonomic functioning following emotional arousal. The shell also receives input from the amygdala and hippocampus regarding affective and contextual attributes of new learning experiences. The successful encoding of affect or context is facilitated by activating noradrenergic systems in either the amygdala or hippocampus. Recent findings indicate that memory enhancement produced by activating NTS neurons, is attenuated by suppressing accumbens functioning after learning. This finding illustrates the significance of the shell in integrating information from the periphery to modulate memory for arousing events. However, it is not known if the accumbens shell plays an equally important role in consolidating information that is initially processed in the amygdala and hippocampus. The present study determined if the convergence of inputs from these limbic regions within the nucleus accumbens contributes to successful encoding of emotional events into memory. Male Sprague-Dawley rats received bilateral cannula implants 2 mm above the accumbens shell and a second bilateral implant 2 mm above either the amygdala or hippocampus. The subjects were trained for 6 days to drink from a water spout. On day 7, a 0.35 mA footshock was initiated as the rat approached the spout and was terminated once the rat escaped into a white compartment. Subjects were then given intra-amygdala or hippocampal infusions of PBS or a dose of norepinephrine (0.2 μg) previously shown to enhance memory. Later, all subjects were given intra-accumbens infusion of muscimol to functionally inactivate the shell. Muscimol inactivation of the accumbens shell was delayed to allow sufficient time for norepinephrine to activate intracellular cascades that lead to long-term synaptic modifications

Uptake mechanism for iodine species to black carbon.

Science.gov (United States)

Choung, Sungwook; Um, Wooyong; Kim, Minkyung; Kim, Min-Gyu

2013-09-17

Natural organic matter (NOM) plays an important role in determining the fate and transport of iodine species such as iodide (I(-)) and iodate (IO3(-)) in groundwater system. Although NOM exists as diverse forms in environments, prior iodine studies have mainly focused on uptake processes of iodide and iodate to humic materials. This study was conducted to determine the iodide and iodate uptake potential for a particulate NOM (i.e., black carbon [BC]). A laboratory-produced BC and commercial humic acid were used for batch experiments to compare their iodine uptake properties. The BC exhibited >100 times greater uptake capability for iodide than iodate at low pH of ~3, while iodide uptake was negligible for the humic acid. The uptake properties of both solids strongly depend on the initial iodine aqueous concentrations. After uptake reaction of iodide to the BC, X-ray absorption fine structure spectroscopy results indicated that the iodide was converted to electrophilic species, and iodine was covalently bound to carbon atom in polycyclic aromatic hydrocarbons present in the BC. The computed distribution coefficients (i.e., Kd values) suggest that the BC materials retard significantly the transport of iodide at low pH in environmental systems containing even a small amount of BC.

Ouabain-binding and 86rubidium-uptake in lymphocytes of normal and borderline hypertensive subjects

DEFF Research Database (Denmark)

Nielsen, J R; Pedersen, K E; Johansen, Torben

1983-01-01

activity were studied in lymphocytes of nine borderline hypertensives (27 (20-36) years) and nine controls (28 (20-36) years). Maximum 3H-ouabain binding and 86Rb-uptake were taken as measures of the number of pump sites and cation pump activity, respectively. The median number of sodium/potassium pump...... to increased cation pump activity in lymphocytes of BH subjects in vitro may be interpreted as an adaptive change possibly induced by a circulating natriuretic substance....

CO and H2 uptake and emissions by soil: variability of fluxes and their isotopic signatures

Science.gov (United States)

Popa, Maria Elena; Chen, Qianjie; Ferrero Lopez, Noelia; Röckmann, Thomas

2017-04-01

In order to study the uptake and release of H2 and CO by soil, we performed long term, high frequency measurements with an automatic soil chamber at two sites in the Netherlands (Cabauw - grassland, and Speuld - forest). The measurements were performed over different seasons and cover in total a cumulated interval of about one year. These measurements allow determining separately, for each species, the two distinct fluxes i.e. uptake and release, and investigating their temporal variability and dependencies on environmental variables. Additional experiments were performed for determining the isotopic signatures of the H2 and CO uptake and release by soil. Flask samples were filled from the soil chamber, and then analyzed in the laboratory for the stable isotopic composition of H2 (δD) and CO (δ13C and δ18O). We find that both uptake and release are present at all times, regardless of the direction of the net flux. The emissions are significant for both species and at Cabauw, there are times and places where emissions outweigh the soil uptake. For each species, the two fluxes have different behavior and dependence on external variables, which indicates that they have different origins. The isotope results also support that, for both H2 and CO, uptake and emission occur simultaneously. We were able to determine separately the isotopic effects of the two fluxes. For both H2 and CO, soil uptake is associated with a small positive fractionation (the lighter molecule is taken up faster). The soil uptake fractionation (α = kheavy/klight) was 0.945 ± 0.004 for H2; for CO, the fractionation was 0.992 for 13C and 0.985 for 18O. The isotopic composition of the H2 emitted from the grassland was -530 ± 40 ‰, less depleted that what is expected from the isotopic equilibrium of H2 with water. For CO, the isotopic composition of the soil emission is depleted in 13C compared to atmospheric CO, and lower than the average isotopic composition of plant or soil organic matter.

Platinum uptake from chloride solutions using biosorbents

Directory of Open Access Journals (Sweden)

Mehmet Hakan Morcali

2013-04-01

Full Text Available Present work investigates platinum uptake from synthetically prepared, dilute platinum-bearing solutions using biomass residues, i.e. pistachio nut shell and rice husk, which are abundant in Turkey, and provides a comparison between these two biosorbents. Effects of the different uptake parameters, sorbent dosage, contact time, temperature and pH of solution on platinum uptake (% were studied in detail on a batch sorption. Before the pistachio nut shell was activated, platinum uptake (% was poor compared to the rice husk. However, after the pistachio nut shell was activated at 1000 °C under an argon atmosphere, the platinum uptake (% increased two-fold. The pistachio nut shell (original and activated and rice husk were shown to be better than commercially available activated carbon in terms of adsorption capacity. These two sorbents have also been characterized by FTIR and SEM. Adsorption equilibrium data best complied with the Langmuir isotherm model. Maximum adsorption capacities, Qmax, at 25 °C were found to be 38.31 and 42.02 mg.g- 1for the activated pistachio nut shell and rice husk, respectively. Thermodynamic calculations using the measured ∆H°, ∆S° and ∆G° values indicate that the uptake process was spontaneous and endothermic. The experimental data were shown to be fit the pseudo-second-order kinetic model.

Uptake of SPECT radiopharmaceuticals in neocortical brain cultures

Energy Technology Data Exchange (ETDEWEB)

Jong, B.M. de; Royen, E.A. van

1989-01-01

The uptake, retention and uptake antagonism of /sup 201/Tl-DDC, /sup 201/Tl-Cl, /sup 123/I-IMP, /sup 99m/Tc-HMPAO and /sup 99m/Tc-O4/sup -/ were compared in rat neocortex cultures. /sup 201/Tl-DDC and /sup 123/I-IP revealed the highest uptake of radioactivity in the cultures. /sup 99m/Tc-HMPAO and /sup 123/I-IMP showed the highest retention of radioactivity within the tissue in washout experiments. Blocking of bioelectric activity by tetrodotoxin did not significantly affect the uptake of the radiopharmaceuticals (RPHA). Inhibition of Na K ATPase by ouabain inhibited the uptake of /sup 201/Tl-Cl (77%) and /sup 201/Tl-DDC (27%). Imipramine showed a significantly stronger inhibitory effect on /sup 123/I-IMP uptake in comparison with the effect on other RPHA. /sup 99m/Tc-O4/sup -/ was not concentrated within the cultured tissue. Under the in vitro conditions used in this study, the various RPHA were characterised by distinct differences in their interaction with cortical brain tissue.

Uptake of wheel-filtration among clients of a supervised injecting facility: Can structured education work?

Science.gov (United States)

Steele, Maureen; Silins, Edmund; Flaherty, Ian; Hiley, Sarah; van Breda, Nick; Jauncey, Marianne

2018-01-01

Wheel-filtration of pharmaceutical opioid tablets is a recognised harm reduction strategy, but uptake of the practice among people who inject drugs is low. The study aimed to: (i) examine perceptions of filtration practices; (ii) provide structured education on wheel-filtration; and (iii) assess uptake of the practice. Frequent opioid tablet injectors (n = 30) attending a supervised injecting facility in Sydney, Australia, received hands-on instruction on wheel-filtration based on recommended practice. Pre-education, post-education and follow-up questionnaires were administered. Wheel-filtration was generally regarded as better than cotton-filtration (the typical method) in terms of perceived effects on health, ease of use and overall drug effect. Sixty-eight percent of those who said they would try wheel-filtration after the education had actually done so. Of those who usually used cotton-filtration, over half (60%) had used wheel-filtration two weeks later. Uptake of safer preparation methods for pharmaceutical opioid tablets increases after structured education in wheel-filtration. Findings suggest that SIFs are an effective site for this kind of education. Supervised injecting facility workers are uniquely positioned to provide harm reduction education at the time of injection. [Steele M, Silins E, Flaherty I, Hiley S, van Breda N, Jauncey M. Uptake of wheel-filtration among clients of a supervised injecting facility: Can structured education work? Drug Alcohol Rev 2018;37:116-120]. © 2017 Australasian Professional Society on Alcohol and other Drugs.

Incidence and characteristics of uterine leiomyomas with FDG uptake

International Nuclear Information System (INIS)

Nishizawa, Sadahiko; Inubushi, Masayuki; Kido, Aki; Miyagawa, Masao; Inoue, Takeshi; Shinohara, Katsura; Kajihara, Makoto

2008-01-01

Uterine leiomyomas sometimes show focal 18 F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) images that may result in a false-positive diagnosis for malignant lesions. This study was conducted to investigate the incidence and characteristics of uterine leiomyomas that showed FDG uptake. We reviewed FDG-PET and pelvic magnetic resonance (MR) images of 477 pre-menopausal (pre-MP, age 42.1±7.3 years) and 880 post-MP (age 59.9±6.8 years) healthy women who underwent these tests as parts of cancer screening. Of 1357, 323 underwent annual cancer screening four times, 97 did three times, 191 did twice, and the rest were screened once. Focal FDG uptake (maximal standardized uptake value >3.0) in the pelvis was localized and characterized on co-registered PET/MR images. Uterine leiomyomas were found in 164 pre-MP and 338 post-MP women. FDG uptake was observed in 18 leiomyomas of 17 of the 164 (10.4%) pre-MP women and in 4 leiomyomas of 4 of the 338 (1.2%) post-MP women. The incidence was significantly higher in pre-MP women than in post-MP women (chi-square, P<0.001). Of the 22, 13 showed signal intensity equal to or higher than that of the myometrium on T2-weighted MR images, which suggested abundant cellularity, whereas the majority of leiomyomas without FDG uptake showed low signal intensity. Of the 13 women, 12 examined more than twice showed substantial changes in the level of FDG uptake in leiomyomas each year with FDG uptake disappearing or newly appearing. These changes were observed frequently in relation with menopause or menstrual phases. Leiomyomas with focal FDG uptake were seen in both pre- and post-MP women with a higher incidence in pre-MP women. Abundant cellularity and hormonal dependency may explain a part of the mechanisms of FDG uptake in leiomyomas. It is important to know that the level of FDG uptake in leiomyomas can change and newly appearing FDG uptake does not necessarily mean malignant transformation. (author)

Nitrite uptake by nitrogen-depleted wheat seedlings

Energy Technology Data Exchange (ETDEWEB)

Jackson, W A; Johnson, R E; Volk, R J

1974-01-01

Intact, 14-day-old nitrogen-depleted wheat (Triticum vulgare cv. Blueboy) seedlings were exposed to solutions of 0.5 mM KNO/sub 2/, 0.05 mM CaSO/sub 4/ and 1 mM sodium 2-(N-morpholino)-ethanesulfonate, pH 6.1. Nitrite uptake was determined from depletion of the ambient solution or from incorporation of /sup 15/N in the tissue. An initial nitrite uptake shoulder was followed by a relatively slow uptake rate which subsequently increased to a substantially greater rate. This accelerated phase was maintained through 24 h. Nitrite accumulated to a slight extent in the root tissues during the first few hours but declined to low values when the accelerated rate was fully developed, indicating an increase in nitrite reductase activity paralleling the increase in nitrite uptake capacity. About 50% of the nitrogen absorbed as nitrite was translocated to the shoots by 9 to 12 h. Development of the accelerated nitrite uptake rate was restricted in excised roots, in intact plants kept in darkness, by 400 ..mu..g puromycin ml/sup -1/ and by 1 mM L-ethionine. When puromycin and L-ethionine were added after the accelerated phase had been initiated, their effects were not as detrimental as when they were added at first exposure to KNO/sub 2/. The two inhibitors restricted translocation more than uptake. The data indicate an involvement of protein synthesis and a requirement for movement of a substance from shoots to roots for maximal development of the accelerated nitrite uptake phase. A requirement for protein synthesis in the transport of soluble organic nitrogen from roots to shoots is also suggested.

Caudal fourth ventricular administration of the AMPK activator 5-aminoimidazole-4-carboxamide-riboside regulates glucose and counterregulatory hormone profiles, dorsal vagal complex metabolosensory neuron function, and hypothalamic Fos expression.

Science.gov (United States)

Ibrahim, Baher A; Tamrakar, Pratistha; Gujar, Amit D; Cherian, Ajeesh Koshy; Briski, Karen P

2013-09-01

This study investigated the hypothesis that estrogen controls hindbrain AMP-activated protein kinase (AMPK) activity and regulation of blood glucose, counterregulatory hormone secretion, and hypothalamic nerve cell transcriptional status. Dorsal vagal complex A2 noradrenergic neurons were laser microdissected from estradiol benzoate (E)- or oil (O)-implanted ovariectomized female rats after caudal fourth ventricular (CV4) delivery of the AMPK activator 5-aminoimidazole-4-carboxamide-riboside (AICAR), for Western blot analysis. E advanced AICAR-induced increases in A2 phospho-AMPK (pAMPK) expression and in blood glucose levels and was required for augmentation of Fos, estrogen receptor-α (ERα), monocarboxylate transporter-2, and glucose transporter-3 protein in A2 neurons and enhancement of corticosterone secretion by this treatment paradigm. CV4 AICAR also resulted in site-specific modifications in Fos immunolabeling of hypothalamic metabolic structures, including the paraventricular, ventromedial, and arcuate nuclei. The current studies demonstrate that estrogen regulates AMPK activation in caudal hindbrain A2 noradrenergic neurons during pharmacological replication of energy shortage in this area of the brain, and that this sensor is involved in neural regulation of glucostasis, in part, through control of corticosterone secretion. The data provide unique evidence that A2 neurons express both ERα and -β proteins and that AMPK upregulates cellular sensitivity to ERα-mediated signaling during simulated energy insufficiency. The results also imply that estrogen promotes glucose and lactate uptake by these cells under those conditions. Evidence for correlation between hindbrain AMPK and hypothalamic nerve cell genomic activation provides novel proof for functional connectivity between this hindbrain sensor and higher order metabolic brain loci while demonstrating a modulatory role for estrogen in this interaction. Copyright © 2013 Wiley Periodicals, Inc.

FDG uptake in the stomach

International Nuclear Information System (INIS)

Yun, M. J.; Cho, H. J.; Cho, E. H.; Kim, T. S.; Kang, W. J.; Lee, J. D.

2007-01-01

This study was performed to evaluate histopathologic features of advanced gastric cancer (AGC) to predict FDG uptake on PET. 153 patients(102 men; mean age, 55 y) were diagnosed with AGC by surgery were included in this study. PET images were evaluated by visual and semi-quantitative analysis of FDG uptake in primary tumors. Primary tumors size were measured and divided according to Borrmann classification. Tumor histology was classified under WHO classification, depth of invasion and Iymphovascular invasion. The tumors were also grouped by high cellular(cellularity = 50%) and low cellular group (<50%). Microscopic growth type was based on Lauren classification. Stromal fibrosis degree and inflammatory cell infiltration amount was graded as low(none∼mild), or high(moderate∼severe). Lymph node metastases was assessed in all patients. Statistical analyses were performed to evaluate differences in SUV as to histopathologic factors. Of the 153 patients, 21 patients(14%) had primary tumor invisible on initial whole body images. After water ingestion, the tumors became visible in 15 of the 21 patients due to disappearance of physiologic stomach uptake. Polypoid or ulcerofungating tumors, high cellularity, intestinal growth pattern, and larger tumors significantly predicted increased tumor SUVs. Well or moderately differentiated adenocarcinoma tended to show high cellularity and intestinal growth pattern. Poorly differentiated adenocarcinoma had diverse spectrum of histopathology. Signet ring cell carcinomas were mostly ulceroinfiltrative or diffusely infiltrative in macroscopic type and diffuse in microscopic tumor growth. Mucinous adenocarcinomas were mostly low in cellularity. FDG uptake patterns are useful in representing histopathologic characteristics of the entire tumor in gastric cancers. The degree of FDG uptake depends on tumor size, macroscopic type, cellularity, and microscopic growth pattern and it shows no association with well known important prognostic

Specific in vitro uptake of serotonin by cells in the anterior pituitary of the rat

International Nuclear Information System (INIS)

Johns, M.A.; Azmitia, E.C.; Krieger, D.T.

1982-01-01

In vivo studies have suggested that serotonin (5HT) influences anterior pituitary function at the hypothalamic level. The present in vitro study investigated the possibility that 5HT may act directly on the anterior pituitary. The high affinity uptake of [3H]5HT into adult rat anterior pituitary tissue was examined in two types of experiments. 1) To test the specificity and saturability of uptake of 5HT in the anterior pituitary, pituitary tissue was incubated (37 C) with [3H]5HT (10(-8)-10(-6) M) in the presence and absence of excess (10(-5) M) unlabeled 5HT, norepinephrine, fluoxetine (FLUOX), metergoline, or cyproheptadine. A Hofstee analysis of the specific uptake of [3H]5HT gave an apparent Km value of 4.23 x 10(-7) M and a Vmax of 1576 pmol/g/10 min [3H]5HT. The total uptake of [3H]5HT was not altered by norepinephrine or metergoline, but was significantly reduced (P less than 0.01-0.001) by FLUOX and cyproheptadine. Uptake was shown to be temperature and sodium dependent and not directly dependent on energy derived from glycolysis or aerobic metabolism. 2) To study the site of uptake of 5 HT in the anterior pituitary, in concomitant radioautographic experiments, tissue was incubated with [3H]5HT with and without excess 5HT or FLUOX. Three patterns of silver grain distribution were observed: 1) nonrandom concentrations over select anterior pituitary cells near blood vessels, 2) heavy aggregates of silver grains usually associated with blood vessels, and 3) a seemingly random dispersal of grains over pituitary tissue. Tissue incubated with [3H]5HT alone contained 10% heavily labeled cells, 32% moderately labeled cells, and 58% weakly labeled cells. In contrast, no heavily labeled cells were seen when tissue was incubated with either excess 5HT or FLUOX in addition to [3H]5HT. Our findings of saturable and specific high affinity uptake of [3H]5HT into a subgroup of anterior pituitary cells suggest a direct pituitary action of 5HT

Correlation of hepatic 18F-fluorodeoxyglucose uptake with fatty liver

International Nuclear Information System (INIS)

An, Young Sil; Yoon, Joon Kee; Hong, Seon Pyo; Joh, Chul Woo; Yoon, Seok Nam

2006-01-01

Liver demonstrates heterogeneous FDG uptake and sometimes it shows abnormally increased uptake even though there is no malignant tissue. However, there was no previous study to correlate these various pattern of hepatic FDG uptake with benign liver disease. Therefore, we evaluated the significance of hepatic FDG uptake associated with various clinical factors including fatty liver, liver function tests and lipid profiles. We reviewed a total of 188 patients (male/female: 120/68, mean age: 50 ± 9) who underwent PET/CT for screening of malignancy. Patients with DM, impaired glucose tolerance, previous severe hepatic disease or long-term medication history were excluded. The FDG uptake in liver was analyzed semi-quantitatively using ROI on transaxial images (segment 8) and we compared mean standardized uptake value (SUV) between fatty liver and non-fatty liver group. We also evaluated the correlation between hepatic FDG uptake and various clinical factors including serum liver function test (ALT, AST), γ -GT, total cholesterol and triglyceride concentration. The effect of alcoholic history and body mass index on hepatic FDG uptake was analyzed within the fatty liver patients. The hepatic FDG uptake of fatty liver group was significantly higher than that of non-fatty liver group. Serum total cholesterol and triglyceride concentration showed significant correlation with hepatic FDG uptake. However, there was no significant correlation between other factors (ALT, AST, and γ -GT) and FDG uptake. Also there was no difference of mean SUV between normal and abnormal groups on the basis of alcoholic history and body mass index within fatty liver patients. Fatty liver and high serum triglyceride concentration were the independent factors affecting hepatic FDG uptake according to multivariate analysis. In conclusion, hepatic FDG uptake was strongly correlated with fatty liver and serum triglyceride concentration

Uptake of organic nitrogen by plants

Science.gov (United States)

Torgny Nasholm; Knut Kielland; Ulrika. Ganeteg

2009-01-01

Languishing for many years in the shadow of plant inorganic nitrogen (N) nutrition research, studies of organic N uptake have attracted increased attention during the last decade. The capacity of plants to acquire organic N, demonstrated in laboratory and field settings, has thereby been well established. Even so, the ecological significance of organic N uptake for...

Gallium 67 uptake in thymic rebound

International Nuclear Information System (INIS)

Hurst, R.; Sabio, H.; Teates, C.D.

1988-01-01

We have reported a case of localized thymic enlargement and uptake of gallium 67 in a child who had received antineoplastic chemotherapy. The enlarged thymus showed normal histology, a picture consistent with thymic rebound after nonspecific stress. This case further demonstrates the need to consider thymic rebound as a cause of gallium 67 uptake in children with neoplastic diseases

Metallofullerenol Inhibits Cellular Iron Uptake by Inducing Transferrin Tetramerization.

Science.gov (United States)

Li, Jinxia; Xing, Xueqing; Sun, Baoyun; Zhao, Yuliang; Wu, Zhonghua

2017-10-18

Herein, A549 tumor cell proliferation was confirmed to be positively dependent on the concentration of Fe 3+ or transferrin (Tf). Gd@C 82 (OH) 22 or C 60 (OH) 22 effectively inhibited the iron uptake and the subsequent proliferation of A549 cells. The conformational changes of Tf mixed with FeCl 3 , GdCl 3 , C 60 (OH) 22 or Gd@C 82 (OH) 22 were obtained by SAXS. The results demonstrate that Tf homodimers can be decomposed into monomers in the presence of FeCl 3 , GdCl 3 or C 60 (OH) 22 , but associated into tetramers in the presence of Gd@C 82 (OH) 22 . The larger change of SAXS shapes between Tf+C 60 (OH) 22 and Tf+FeCl 3 implies that C 60 (OH) 22 is bound to Tf, blocking the iron-binding site. The larger deviation of the SAXS shape from a possible crystal structure of Tf tetramer implies that Gd@C 82 (OH) 22 is bound to the Tf tetramer, thus disturbing iron transport. This study well explains the inhibition mechanism of Gd@C 82 (OH) 22 and C 60 (OH) 22 on the iron uptake and the proliferation of A549 tumor cells and highlights the specific interactions of a nanomedicine with the target biomolecules in cancer therapy. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clinical significance of abnormal nonosseous soft tissue uptake of bone tracer

International Nuclear Information System (INIS)

Zhu Bao; Shang Yukun; Li Jiannan; Bai Jing; Cai Liang

2006-01-01

Objective: To evaluate the clinical significance of abnormal soft tissue uptake of bone tracer. Methods: Thirty patients with abnormal soft tissue uptake of bone tracer on 99 Tc m -methylene diphosphonic acid (MDP) skeletal imaging were analyzed. Radioactivity of soft tissue accumulated equal to or greater than the ribs were considered as abnormal. The result was compared with pathology, MRI, CT, X-ray, ultrasound, findings for evaluating its clinical significance. Results: In 7 patients with diffuse liver uptake of 99 Tc m -MDP, 6 were massive and 1 nodular liver cancer. In 2 patients with local liver uptake, one was metastatic and the other primary liver cancer. In 5 local lung uptake cases 4 were primary lung cancer and one metastatic. In 5 cases with colonic uptake 1 was schistosomiasis while the other 4 unexplainable. Subcutaneous tissue uptake was observed in 4 patients, symmetrical uptake in 2 patients with metastatic calcification microfoci in multiple myeloma, unsymmetrical uptake in 2 patients with hemangioma and abscess. Pleural uptake in 3 patients all was metastatic cancer. Abdominal uptake in 3 patients was omentum, paravertebral soft tissue metastasis and unknown cause. Breast uptake in one patient was due to breast cancer. Conclusions: There are many causes resulting in abnormal nonosseous soft tissue uptake of 99 Tc m -MDP. The final diagnosis should correlate with clinical data and other examinations. (authors)

Uptake of proline by the scutellum of germinating barley grain

International Nuclear Information System (INIS)

Vaeisaenen, E.; Sopanen, T.

1986-01-01

Scutella separated from germinating grains of barley (Hordeum vulgare L. cv Himalaya) took up 1 millimolar L-[ 14 C]proline at an initial rate of about 6.5 micromoles gram -1 fresh weight hour -1 (pH 5, 30 0 C). The uptake had a pH optimum at 5. The bulk of the uptake (93%) was via carrier-mediated active transport. All of the 19 L-amino acids tested at 10 millimolar concentration inhibited the mediated uptake of 1 millimolar proline, the inhibitions varying from 18 to 76%. By studying how large a fraction of the mediated uptake was inhibitable by asparagine, alanine, glutamine, and leucine, the mediated uptake was shown to be due to three components. Two of these are most probably attributable to the two nonspecific uptake systems proposed earlier to act in the uptake of glutamine and leucine. The third component was not inhibited by glutamine, asparagine, or alanine, but was inhibited by unlabeled proline and leucine. The uptake by this system was apparently carrier-mediated active transport. D-Proline inhibited this system as strongly as L-proline. Nine of the 16 L-amino tested at 50 millimolar concentrations did not inhibit the uptake of 1 millimolar proline by this system. Valine, leucine, isoleucine, and the basic amino acids were inhibitory, but in spite of this, they did not appear to be taken up by this system. It seems therefore that in addition to two nonspecific amino acid uptake systems the scutella have an uptake system which is specific for proline. It is likely that this proline-specific system accounts for the bulk of proline uptake in a germinating grain

Quantitative 99mTc diphosphonate uptake measurements

International Nuclear Information System (INIS)

Smith, M.L.

1987-01-01

There are several different techniques currently in use for quantifying diphosphonate uptake by the skeleton. These can be considered in two main categories: local bone or whole-body uptake measurements. The choice of technique depends on the clinical problem being investigated and also on available equipment an expertise. The wide variety of approaches to diphosphonate quantitation ensures that these measurements can be obtained in almost any nuclear medicine department. This chapter discusses the general factors which may influence diphosphonate uptake measurements and outlines the techniques most relevant to current clinical practice

Experimental increase in brain HIPDM uptake by hypercapnia

International Nuclear Information System (INIS)

Karatzas, N.D.; Sfakianakis, G.N.; Pappas, D.; Duncan, R.; Heal, A.; Serafini, A.; Kung, H.F.

1988-01-01

The 30-min brain uptake of [ 125 I]HIPDM was measured in conscious rats--normocapnic (n = 8), hypercapnic (n = 12), and hyperoxic (n = 6). A mean 41.2% higher uptake was found in the brains of hypercapnic animals (p less than 0.01). In the three groups of rats, brain HIPDM uptake had a negative correlation with body weight (p less than 0.001) and a positive correlation with arterial pCO 2 (p less than 0.01), when adjusted for body weight. These results indicate that HIPDM uptake with hypercapnia may be used as a provocative test to measure cerebral blood flow reserves

Metals uptake by live yeast and heat-modified yeast residue

Directory of Open Access Journals (Sweden)

Geórgia Labuto

2015-07-01

Full Text Available This study evaluated the biosorption of Cd2+, Cr3+, Pb2+ and Cu2+ at pHs 3, 4, 5 and 6 for Saccharomyces cerevisiae both alive and biologically inactivated by different heating procedures (oven, autoclave or spray dry technique originated from alcohol industry. The material inactivated by autoclave (IA, at 120°C, 30 min had the best performance for metals uptake: 1.88 ± 0.07 (Cu2+, 2.22 ± 0.02 (Cr3+ and 1.57 ± 0.08 g kg-1 (Pb2+. For Cd2+; while the material inactivated by spray dry (RY presented the higher sorption capacity, 2.30 ± 0.08 g kg-1. The sorption studies showed that the biosorbent materials presented different sorption capacities and an ideal sorption pH. The sorption sites were investigated by potentiometric titration and FT-IR and showed that different heating processes used to inactivate biological samples produce materials with different characteristics and with a diverse sorption capacity due to modification of the available sorption sites. This suggests that inactivation by heating can be an alternative to improve the performance of biosorbents. The main sorption sites for each material were phenolic for live yeast (LY and carboxylic for yeast inactivated by heating in an autoclave (IA.

Fluorine-18 fluorodeoxyglucose splenic uptake from extramedullary hematopoiesis after granulocyte colony-stimulating factor stimulation.

Science.gov (United States)

Abdel-Dayem, H M; Rosen, G; El-Zeftawy, H; Naddaf, S; Kumar, M; Atay, S; Cacavio, A

1999-05-01

Two patients with sarcoma, one with recurrent osteosarcoma of the spine and the other with metastatic synovial cell sarcoma, were treated with high-dose chemotherapy that produced severe leukopenia. The patients received granulocyte colony-stimulating factor (G-CSF) to stimulate the bone marrow (480 mg given subcutaneously twice daily for 5 to 7 days); their responses were seen as a marked increase in peripheral leukocyte count with no change in the erythrocyte or platelet counts. The patients had fluorine-18 fluorodeoxyglucose (F-18 FDG) imaging 24 hours after the end of G-CSF treatment. Diffusely increased uptake of F-18 FDG was seen in the bone marrow in both patients. In addition, markedly increased uptake in the spleen was noted in both, indicating that the spleen was the site of extramedullary hematopoiesis. The patients had no evidence of splenic metastases. The first patient had a history of irradiation to the dorsal spine, which was less responsive to G-CSF administration than was the nonirradiated lumbar spine.

Evaluations of Mechanisms for Pu Uptake and Retention within Spherical Resorcinol-Formaldehyde Resin Columns

Energy Technology Data Exchange (ETDEWEB)

Delegard, Calvin H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Levitskaia, Tatiana G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fiskum, Sandra K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-09-15

The unexpected uptake and retention of plutonium (Pu) onto columns containing spherical resorcinol-formaldehyde (sRF) resin during ion exchange testing of Cs (Cs) removal from alkaline tank waste was observed in experiments at both the Pacific Northwest National Laboratory (PNNL) and the Savannah River National Laboratory (SRNL). These observations have raised concern regarding the criticality safety of the Cs removal unit operation within the low-activity waste pretreatment system (LAWPS). Accordingly, studies have been initiated at Washington River Protection Solutions (WRPS), who manages the operations of the Hanford Site tank farms, including the LAWPS, PNNL, and elsewhere to investigate these findings. As part of these efforts, PNNL has prepared the present report to summarize the laboratory testing observations, evaluate these phenomena in light of published and unpublished technical information, and outline future laboratory testing, as deemed appropriate based on the literature studies, with the goal to elucidate the mechanisms for the observed Pu uptake and retention.

Metallic mercury uptake by catalase Part 1 In Vitro metallic mercury uptake by various kind of animals' erythrocytes and purified human erythrocyte catalase

OpenAIRE

劒持,堅志

1980-01-01

The uptake of metallic mercury was studied using erythrocytes with different catalase activities taken from various kind of animals. The results were: 1) The uptake of metallic mercury by erythrocytes paralleled the activity of catalase in the erythrocytes with and without hydrogen peroxide, suggesting that the erythrocyte catalase activity is related to the uptake of metallic mercury. 2) The uptake of metallic mercury occurred not only with purified human erythrocyte catalase but also with h...

Ion Mobility Spectrometry-Hydrogen Deuterium Exchange Mass Spectrometry of Anions: Part 2. Assessing Charge Site Location and Isotope Scrambling

Science.gov (United States)

Khakinejad, Mahdiar; Ghassabi Kondalaji, Samaneh; Donohoe, Gregory C.; Valentine, Stephen J.

2016-03-01

Ion mobility spectrometry (IMS) coupled with gas-phase hydrogen deuterium exchange (HDX)-mass spectrometry (MS) and molecular dynamic simulations (MDS) has been used for structural investigation of anions produced by electrospraying a sample containing a synthetic peptide having the sequence KKDDDDDIIKIIK. In these experiments the potential of the analytical method for locating charge sites on ions as well as for utilizing collision-induced dissociation (CID) to reveal the degree of deuterium uptake within specific amino acid residues has been assessed. For diffuse (i.e., more elongated) [M - 2H]2- ions, decreased deuterium content along with MDS data suggest that the D4 and D6 residues are charge sites, whereas for the more diffuse [M - 3H]3- ions, the data suggest that the D4, D7, and the C-terminus are deprotonated. Fragmentation of mobility-selected, diffuse [M - 2H]2- ions to determine deuterium uptake at individual amino acid residues reveals a degree of deuterium retention at incorporation sites. Although the diffuse [M - 3H]3- ions may show more HD scrambling, it is not possible to clearly distinguish HD scrambling from the expected deuterium uptake based on a hydrogen accessibility model. The capability of the IMS-HDX-MS/MS approach to provide relevant details about ion structure is discussed. Additionally, the ability to extend the approach for locating protonation sites on positively-charged ions is presented.

Uptake and depuration of pharmaceuticals in aquatic invertebrates

International Nuclear Information System (INIS)

Meredith-Williams, Melanie; Carter, Laura J.; Fussell, Richard; Raffaelli, David; Ashauer, Roman; Boxall, Alistair B.A.

2012-01-01

The uptake and depuration of a range of pharmaceuticals in the freshwater shrimp (Gammarus pulex) and the water boatman (Notonecta glauca) was studied. For one compound, studies were also done using the freshwater snail Planobarius corneus. In G. pulex, bioconcentration factors (BCFs) ranged from 4.6 to 185,900 and increased in the order moclobemide < 5-fluoruracil < carbamazepine < diazepam < carvedilol < fluoxetine. In N. glauca BCFs ranged from 0.1 to 1.6 and increased in the order 5-fluorouracil < carbamazepine < moclobemide < diazepam < fluoxetine < carvedilol. For P. corneus, the BCF for carvedilol was 57.3. The differences in degree of uptake across the three organisms may be due to differences in mode of respiration, behaviour and the pH of the test system. BCFs of the pharmaceuticals for each organism were correlated to the pH-corrected liposome–water partition coefficient of the pharmaceuticals. - Highlights: ► One of the first studies exploring the uptake of pharmaceuticals into aquatic invertebrates. ► Data presented on uptake, depuration rates and bioconcentration for a range of pharmaceuticals. ► Uptake is correlated with the pH-corrected liposome–water partition coefficient. ► Findings can be used to better predict impacts of pharmaceuticals on the aquatic environment. - The factors affecting the degree of uptake of pharmaceuticals into aquatic invertebrates were studied. The results indicate that species traits such as respiration and behaviour of the organisms and pH-corrected liposome–water partition coefficients are important factors in determining pharmaceutical uptake.

Uptake of inorganic contaminants by pteridophytes

International Nuclear Information System (INIS)

Zheng Jiemin; Chen Ziyuan; Tang Shirong; Guangzhou Univ., Guangzhou; Ding Bingyang

2005-01-01

The review covers results at home and abroad in terms of uptake of inorganic contaminants by pteridophytes, and suggests pteridophytes' significance in phytoremediation; the mechanisms related to uptake of inorganic contaminants by pteridophytes and some methods and means used for research on the mechanism are also introduced; the authors' viewpoints on future development trends are presented in this paper. (authors)

Radio-active iodine uptake in vitiligo

Energy Technology Data Exchange (ETDEWEB)

Kumar, V.; Shankar, V.; Chaudhary, S.; Bhatia, K.K.; Mehta, L.K.; Arora, D.R. (Medical College and Hospital, Rohtak-124001 (India))

1990-01-01

Vitiligo and thyroid disease are commonly associated disorders. Twenty-two clinically euthyroid vitiligo patients were studied for functional assessment of thyroid by radioactive iodine uptake assay. Half of them showed abnormal uptake values at 24 hours. Of these patients, 90% had lower values indicating a tendency towards developing hypothyroid state. Subclinical thyroid dysfunction in vitiligo appears to be an adaptive change. (author).

Radio-active iodine uptake in vitiligo

International Nuclear Information System (INIS)

Kumar, V.; Shankar, V.; Chaudhary, S.; Bhatia, K.K.; Mehta, L.K.; Arora, D.R.

1990-01-01

Vitiligo and thyroid disease are commonly associated disorders. Twenty-two clinically euthyroid vitiligo patients were studied for functional assessment of thyroid by radioactive iodine uptake assay. Half of them showed abnormal uptake values at 24 hours. Of these patients, 90% had lower values indicating a tendency towards developing hypothyroid state. Subclinical thyroid dysfunction in vitiligo appears to be an adaptive change. (author)

Determinants in the uptake of the human papillomavirus vaccine

DEFF Research Database (Denmark)

de Casadevante, Victoria Fernández; Cuesta, Julita Gil; Cantarero Arevalo, Lourdes

2015-01-01

of HPVV uptake in Europe. Methods: We performed a systematic Pubmed, Scopus, and Science Direct search to find articles published from HPVV availability in European countries until April 2014. No age restriction was applied. We included all studies assessing factors associated with HPVV uptake. Uptake...

Methionine Uptake and Required Radiation Dose to Control Glioblastoma

Energy Technology Data Exchange (ETDEWEB)

Iuchi, Toshihiko, E-mail: tiuchi@chiba-cc.jp [Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Hatano, Kazuo [Division of Radiation Oncology, Tokyo Bay Advanced Imaging and Radiation Oncology Clinic, Makuhari, Chiba (Japan); Uchino, Yoshio [Division of Nuclear Medicine, Chiba Ryogo Center, Chiba (Japan); Itami, Makiko [Division of Surgical Pathology, Chiba Cancer Center, Chiba (Japan); Hasegawa, Yuzo; Kawasaki, Koichiro; Sakaida, Tsukasa [Division of Neurological Surgery, Chiba Cancer Center, Chiba (Japan); Hara, Ryusuke [Division of Radiation Oncology, Chiba Cancer Center, Chiba (Japan)

2015-09-01

Purpose: The purpose of this study was to retrospectively assess the feasibility of radiation therapy planning for glioblastoma multiforme (GBM) based on the use of methionine (MET) positron emission tomography (PET), and the correlation among MET uptake, radiation dose, and tumor control. Methods and Materials: Twenty-two patients with GBM who underwent MET-PET prior to radiation therapy were enrolled. MET uptake in 30 regions of interest (ROIs) from 22 GBMs, biologically effective doses (BEDs) for the ROIs and their ratios (MET uptake:BED) were compared in terms of whether the ROIs were controlled for >12 months. Results: MET uptake was significantly correlated with tumor control (odds ratio [OR], 10.0; P=.005); however, there was a higher level of correlation between MET uptake:BED ratio and tumor control (OR, 40.0; P<.0001). These data indicated that the required BEDs for controlling the ROIs could be predicted in terms of MET uptake; BED could be calculated as [34.0 × MET uptake] Gy from the optimal threshold of the MET uptake:BED ratio for tumor control. Conclusions: Target delineation based on MET-PET was demonstrated to be feasible for radiation therapy treatment planning. MET-PET could not only provide precise visualization of infiltrating tumor cells but also predict the required radiation doses to control target regions.

Increased muscle glucose uptake after exercise

DEFF Research Database (Denmark)

Richter, Erik; Ploug, Thorkil; Galbo, Henrik

1985-01-01

responsiveness of glucose uptake was noted only in controls. Analysis of intracellular glucose-6-phosphate, glucose, glycogen synthesis, and glucose transport suggested that the exercise effect on responsiveness might be due to enhancement of glucose disposal. After electrical stimulation of diabetic...... of glucose. At maximal insulin concentrations, the enhancing effect of exercise on glucose uptake may involve enhancement of glucose disposal, an effect that is probably less in muscle from diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)......It has recently been shown that insulin sensitivity of skeletal muscle glucose uptake and glycogen synthesis is increased after a single exercise session. The present study was designed to determine whether insulin is necessary during exercise for development of these changes found after exercise...

A strategy for increasing the brain uptake of a radioligand in animals: use of a drug that inhibits plasma protein binding

International Nuclear Information System (INIS)

Haradahira, Terushi; Zhang, Ming-Rong; Maeda, Jun; Okauchi, Takashi; Kawabe, Kouichi; Kida, Takayo; Suzuki, Kazutoshi; Suhara, Tetsuya

2000-01-01

A positron-emitter labeled radioligand for the glycine-binding site of the N-methyl-D-aspartate (NMDA) receptor, [ 11 C]L-703,717, was examined for its ability to penetrate the brain in animals by simultaneous use with drugs having high-affinity separate binding sites on human serum albumin. [ 11 C]L-703,717 has poor blood-brain barrier (BBB) permeability because it binds tightly to plasma proteins. Co-injection of warfarin (50-200 mg/kg), a drug that binds to albumin and resembles L-703,717 in structure, dose-dependently enhanced the penetration by [ 11 C]L-703,717 in mice, resulting in a five-fold increase in the brain radioactivity at 1 min after the injection. Drugs structurally unrelated to L-703,717, salicylate, phenol red, and L-tryptophan, were less effective or ineffective in increasing the uptake of [ 11 C]L-703,717. These results suggest that the simultaneous use of a drug that inhibits the binding of a radioligand to plasma proteins is a useful way to overcome the poor BBB permeability of the radioligand triggered by its tight binding to plasma proteins. In brain distribution studies in rodents, it was found that, after the increase in brain uptake with warfarin, much of the glycine site antagonist accumulates in the cerebellum but its pharmacological specificity did not match the glycine site of NMDA receptors

Explaining variation in the uptake of HPV vaccination in England

Directory of Open Access Journals (Sweden)

Whynes David K

2011-03-01

Full Text Available Abstract Background In England, two national programmes of HPV vaccination for girls have been instituted, a routine programme for 12- and 13-year-olds and a catch-up programme for 17- and 18-year-olds. Uptake rates across the country have been far from uniform, and this research sought to identify factors explaining the variation in uptake by locality. Methods An association between uptake, deprivation and ethnic background had been established in pilot research. The present analysis was conducted at an aggregate, Primary Care Trust (PCT, level for the first year of the programmes. Published measures of HPV vaccination uptake, material deprivation, ethnic composition of PCT populations, primary care quality, and uptake of cervical screening and of other childhood immunisations were collated. Strong evidence of collinearity amongst the explanatory variables required a factor analysis to be undertaken. This provided four independent factors, used thereafter in regression models to explain uptake by PCT. Results The factor analysis revealed that ethnic composition was associated with attitudes towards cervical screening and other childhood vaccinations, whilst material deprivation and quality of primary care were orthogonal. Ethnic composition, early childhood vaccination, cervical screening and primary care quality were found to be influential in predicting uptake in both the routine and the catch-up cohorts, although with a lower degree of confidence in the case of the last two independent variables. Lower primary care quality was significant in explaining a greater fall in vaccination uptake between the first two doses in the catch-up cohort. Greater deprivation was a significant explanatory factor for both uptake and the fall in uptake between doses for the catch-up cohort but not for uptake in the routine cohort. Conclusion These results for uptake of the first year of the national programme using aggregate data corroborate findings from

Flavonoid rutin increases thyroid iodide uptake in rats.

Directory of Open Access Journals (Sweden)

Carlos Frederico Lima Gonçalves

Full Text Available Thyroid iodide uptake through the sodium-iodide symporter (NIS is not only an essential step for thyroid hormones biosynthesis, but also fundamental for the diagnosis and treatment of different thyroid diseases. However, part of patients with thyroid cancer is refractory to radioiodine therapy, due to reduced ability to uptake iodide, which greatly reduces the chances of survival. Therefore, compounds able to increase thyroid iodide uptake are of great interest. It has been shown that some flavonoids are able to increase iodide uptake and NIS expression in vitro, however, data in vivo are lacking. Flavonoids are polyhydroxyphenolic compounds, found in vegetables present in human diet, and have been shown not only to modulate NIS, but also thyroperoxidase (TPO, the key enzyme in thyroid hormones biosynthesis, besides having antiproliferative effect in thyroid cancer cell lines. Therefore, we aimed to evaluate the effect of some flavonoids on thyroid iodide uptake in Wistar rats in vivo. Among the flavonoids tested, rutin was the only one able to increase thyroid iodide uptake, so we decided to evaluate the effect of this flavonoid on some aspects of thyroid hormones synthesis and metabolism. Rutin led to a slight reduction of serum T4 and T3 without changes in serum thyrotropin (TSH, and significantly increased hypothalamic, pituitary and brown adipose tissue type 2 deiodinase and decreased liver type 1 deiodinase activities. Moreover, rutin treatment increased thyroid iodide uptake probably due to the increment of NIS expression, which might be secondary to increased response to TSH, since TSH receptor expression was increased. Thus, rutin might be useful as an adjuvant in radioiodine therapy, since this flavonoid increased thyroid iodide uptake without greatly affecting thyroid function.

Effects of compost and phosphate amendments on arsenic mobility in soils and arsenic uptake by the hyperaccumulator, Pteris vittata L

International Nuclear Information System (INIS)

Cao Xinde; Ma, Lena Q.; Shiralipour, Aziz

2003-01-01

Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated-copper-arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil. Soils were treated with phosphate rock, municipal solid waste, or biosolid compost. Phosphate amendments significantly enhanced plant As uptake from the two tested soils with frond As concentrations increasing up to 265% relative to the control. After 12 weeks, plants grown in phosphate-amended soil removed >8% of soil As. Replacement of As by P from the soil binding sites was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions facilitated As uptake from the CCA soil, but decreased As uptake from the ASC soil. Elevated As uptake in the compost-treated CCA soil was related to the increase of soil water-soluble As and As(V) transformation into As(III). Reduced As uptake in the ASC soil may be attributed to As adsorption to the compost. Chinese brake fern took up As mainly from the iron-bound fraction in the CCA soil and from the water-soluble/exchangeable As in the ASC soil. Without ferns for As adsorption, compost and phosphate amendments increased As leaching from the CCA soil, but had decreased leaching with ferns when compared to the control. For the ASC soil, treatments reduced As leaching regardless of fern presence. This study suggest that growing Chinese brake fern in conjunction with phosphate amendments increases the effectiveness of remediating As-contaminated soils, by increasing As uptake and decreasing As leaching. - Phosphate amendment increases the effectiveness of Chinese brake fern to remediate As-contaminated soils, by increasing As uptake and decreasing As leaching

Ficus Deltoidea Enhance Glucose Uptake Activity in Cultured Muscle Cells

International Nuclear Information System (INIS)

Zainah Adam; Shafii Khamis; Amin Ismail; Muhajir Hamid

2015-01-01

Ficus deltoidea or locally known as Mas cotek is one of the common medicinal plants used in Malaysia. Our previous studies showed that this plant have blood glucose lowering effect. Glucose uptake into muscle and adipocytes cells is one of the known mechanisms of blood glucose lowering effect. This study was performed to evaluate the effect of Ficus deltoidea on glucose uptake activity into muscle cells. The cells were incubated with Ficus deltoidea extracts either alone or combination with insulin. Amount of glucose uptake by L6 myotubes was determined using glucose tracer, 2-deoxy-(1- 3 H 1 )-glucose. The results showed that Ficus deltoidea extracts at particular doses enhanced basal or insulin-mediated glucose uptake into muscle cells significantly. Hot aqueous extract enhanced glucose uptake at the low concentration (10 μg/ ml) whereas methanolic extract enhanced glucose uptake at low and high concentrations. Methanolic extract also mimicked insulin activity during enhancing glucose uptake into L^ muscle cells. Glucose uptake activity of Ficus deltoidea could be attributed by the phenolic compound presence in the plant. This study had shown that Ficus deltoidea has the ability to enhance glucose uptake into muscle cells which is partly contributed the antidiabetic activity of this plant. (author)

Factors affecting gastric uptake in whole body FDG-PET imaging

International Nuclear Information System (INIS)

Tomemori, Takashi; Kitagawa, Mami; Nakahara, Tadaki; Wu, Jin; Nakagawa, Keiichi; Uno, Kimiichi; Abe, Kinji; Tomiyoshi, Katsumi

2001-01-01

Positron emission tomography (PET) using 2-deoxy-2-[ 18 F]-fluoro-D-glucose (FDG) is very useful for the detection and staging of tumors. However, FDG is also accumulated in the normal tissues in various degrees. This physiological FDG uptake is often seen in intestine, making confusion with malignant tumor. The aim of this study was to identify factors influencing physiological FDG uptake in the stomach. A total of 136 people who underwent cancer screening or staging of tumors except for gastric cancer using FDG whole-body PET was examined (mean age: 55.6 yrs). All subjects fasted for at least 4 hours before the PET study and were administrated with FDG intravenously (mean FDG dose: 308.9 MBq). Emission images were acquired on a whole-body PET scanner and images were reconstructed without attenuation correction. The intensity of gastric uptake of FDG whole-body PET image was visually classified into 3 grades; grade 2 = the intensity of gastric uptake more than pulmonary uptake, grade 1 = the intensity of gastric uptake equal to or less than pulmonary uptake, grade 0 = no contrast between gastric uptake and background. Twenty-eight subjects (20.6%) were classified into grade 2, 42 subjects (30.9%) were grade 1 and 66 subjects (48.5%) were grade 0. Subjects' age, fasting time, FDG dose, serum glucose level, free fatty acid level and insulin level were not significantly correlated with the intensity of gastric uptake. But the subjects with higher gastric uptake tended to have anti-Helicobactor pylori (H. pylori) antibodies. The rate of having anti-H.pylori antibodies in the grade 2 group is significantly higher than the grade 1 group (85.7% vs. 72.5%, p<0.05), and that of the grade 1 group is significantly higher than the grade 0 group (72.5% vs. 42.2%, p<0.01). Gastric uptake was observed in about half of subjects. Especially, approximately 20% of all showed high gastric uptake, which was associated with H.pylori infection. Therefore, most of the subjects with high

Factors affecting gastric uptake in whole body FDG-PET imaging

Energy Technology Data Exchange (ETDEWEB)

Tomemori, Takashi; Kitagawa, Mami; Nakahara, Tadaki; Wu, Jin; Nakagawa, Keiichi; Uno, Kimiichi; Abe, Kinji; Tomiyoshi, Katsumi [Nishidai Clinic Diagnostic Imaging Center, Tokyo (Japan)

2001-06-01

Positron emission tomography (PET) using 2-deoxy-2-[{sup 18}F]-fluoro-D-glucose (FDG) is very useful for the detection and staging of tumors. However, FDG is also accumulated in the normal tissues in various degrees. This physiological FDG uptake is often seen in intestine, making confusion with malignant tumor. The aim of this study was to identify factors influencing physiological FDG uptake in the stomach. A total of 136 people who underwent cancer screening or staging of tumors except for gastric cancer using FDG whole-body PET was examined (mean age: 55.6 yrs). All subjects fasted for at least 4 hours before the PET study and were administrated with FDG intravenously (mean FDG dose: 308.9 MBq). Emission images were acquired on a whole-body PET scanner and images were reconstructed without attenuation correction. The intensity of gastric uptake of FDG whole-body PET image was visually classified into 3 grades; grade 2 = the intensity of gastric uptake more than pulmonary uptake, grade 1 = the intensity of gastric uptake equal to or less than pulmonary uptake, grade 0 = no contrast between gastric uptake and background. Twenty-eight subjects (20.6%) were classified into grade 2, 42 subjects (30.9%) were grade 1 and 66 subjects (48.5%) were grade 0. Subjects' age, fasting time, FDG dose, serum glucose level, free fatty acid level and insulin level were not significantly correlated with the intensity of gastric uptake. But the subjects with higher gastric uptake tended to have anti-Helicobactor pylori (H. pylori) antibodies. The rate of having anti-H.pylori antibodies in the grade 2 group is significantly higher than the grade 1 group (85.7% vs. 72.5%, p<0.05), and that of the grade 1 group is significantly higher than the grade 0 group (72.5% vs. 42.2%, p<0.01). Gastric uptake was observed in about half of subjects. Especially, approximately 20% of all showed high gastric uptake, which was associated with H.pylori infection. Therefore, most of the subjects

Environmental and cortisol-mediated control of Ca(2+) uptake in tilapia (Oreochromis mossambicus).

Science.gov (United States)

Lin, Chia-Hao; Kuan, Wei-Chun; Liao, Bo-Kai; Deng, Ang-Ni; Tseng, Deng-Yu; Hwang, Pung-Pung

2016-04-01

Ca(2+) is a vital element for many physiological processes in vertebrates, including teleosts, which live in aquatic environments and acquire Ca(2+) from their surroundings. Ionocytes within the adult gills or larval skin are critical sites for transcellular Ca(2+) uptake in teleosts. The ionocytes of zebrafish were found to contain transcellular Ca(2+) transporters, epithelial Ca(2+) channel (ECaC), plasma membrane Ca(2+)-ATPase 2 (PMCA2), and Na(+)/Ca(2+) exchanger 1b (NCX1b), providing information about the molecular mechanism of transcellular Ca(2+) transports mediated by ionocytes in fish. However, more evidence is required to establish whether or not a similar mechanism of transcellular Ca(2+) transport also exists in others teleosts. In the present study, ecac, pmca2, and ncx1 were found to be expressed in the branchial ionocytes of tilapia, thereby providing further support for the mechanism of transcellular Ca(2+) transport through ionocytes previously proposed for zebrafish. In addition, we also reveal that low Ca(2+) water treatment of tilapia stimulates Ca(2+) uptake and expression of ecac and cyp11b (the latter encodes a cortisol-synthesis enzyme). Treatment of tilapia with exogenous cortisol (20 mg/l) enhanced both Ca(2+) influx and ecac expression. Therefore, increased cyp11b expression is suggested to enhance Ca(2+) uptake capacity in tilapia exposed to low Ca(2+) water. Furthermore, the application of cortisol receptor antagonists revealed that cortisol may regulate Ca(2+) uptake through glucocorticoid and/or mineralocorticoid receptor (GR and/or MR) in tilapia. Taken together, the data suggest that cortisol may activate GR and/or MR to execute its hypercalcemic action by stimulating ecac expression in tilapia.

Pollution from mining in South Greenland: Uptake and release of Pb by blue mussels (Mytilus edulis L.) documented by transplantation experiments

DEFF Research Database (Denmark)

Zimmer, L.A.; Asmund, G.; Johansen, P.

2011-01-01

Long-term impact of former mining activities on the marine sub-Arctic ecosystem in the Ivittuut area, Arsuk Fjord, South Greenland, was studied by transplantation experiments with the blue mussel Mytilus edulis. Measurements of metal concentration in mussels were conducted using atomic absorption...... spectrometry (flame AAS) and graphite furnace atomic absorption spectrometry (graphite furnace AAS). Uptake and release of Pb were documented to be slow processes. For mussels transplanted from the pristine Kugnait Bay to the polluted mining site at Ivittuut, a continuous accumulation throughout...... the experiments was found. Linear uptake rates of 5.86, 6.94 and 11.62 μg Pb month−1 for small, medium and large mussels were found for a 6-week experiment, whereas exponential uptake rates of 0.26, 0.20 and 0.28 month−1 were found for a 9-month experiment. It is estimated that the transplanted mussels will reach...

Nitrogen and phosphorus uptake in two Idaho (USA) headwater wilderness streams.

Science.gov (United States)

Davis, Jeffrey C; Minshall, G Wayne

1999-05-01

Nitrate and phosphate solutions were released into two reaches of two central Idaho streams to determine within- and between-stream variability in uptake lengths, uptake rates, and mass transfer coefficients. Physical and biotic stream characteristics and periphyton nitrate-uptake rates in recirculating chambers were measured to determine their influence on nutrient dynamics. Phosphate uptake length did not differ among the four reaches. There were no within-stream differences in nitrate uptake lengths but they did differ between the two streams. Long nitrate uptake lengths likely were due to instream concentrations above saturation but also may have been influenced by differences in active surface area and algal abundance. Nitrate and phosphate uptake lengths were longer, and uptake rates higher, than most other published values. However, mass transfer coefficients were comparable to measurements in other streams. Mass transfer coefficients may be a better parameter for temporal and spatial comparisons of instream nutrient dynamics, and for determining the underlying causes of variability in uptake length.

Bacterial uptake of photosynthetic carbon from freshwater phytoplankton

International Nuclear Information System (INIS)

Coveney, M.F.

1982-01-01

Microheterotrophic uptake of algal extracellular products was studied in two eutrophic lakes in southern Sweden. Size fractionation was used in H 14 CO 3 uptake experiments to measure 14 C fixation in total particulate, small particulate and dissolved organic fractions. Carbon fixed in algal photosynthesis was recovered as dissolved and small particulate 14 C, representing excretion and bacterial uptake of algal products. Estimated gross extracellular release was low in these eutrophic systems, 1 to 7% of total 14 C uptake per m 2 lake surface. From 28 to 80 % of 14 C released was recovered in the small particulate fraction after ca. 4h incubation.This percentage was uniform within each depth profile, but varied directly with in situ water temperature. Laboratory time-series incubations indicated steady state for the pool of algal extracellular products on one occasion, while increasing pool size was indicated in the remaining two experiments. Uptake of photosynthetic carbon to small particles in situ was 32 to 95% of estimted heterotrophic bacterial production (as dark 14 CO 2 uptake) on four occasions. While excretion apparently was not an important loss of cabon for phytoplankton, it may have represented an important carbon source for planktonic bacteria. (author)

Localization of high affinity [3H]glycine transport sites in the cerebellar cortex

International Nuclear Information System (INIS)

Wilkin, G.P.; Csillag, A.; Balazs, R.; Kingsbury, A.E.; Wilson, J.E.; Johnson, A.L.

1981-01-01

A study was made of [ 3 H ]glycine uptake sites in a preparation greatly enriched in large pieces of the cerebellar glomeruli (glomerulus particles) and in morphologically well preserved slices of rat cerebellum. Electron microscopic autoradiography revealed that of the neurones in the cerebellar cortex only Golgi cells transported [ 3 H]glycine at the low concentration used. Glial cells also took up [ 3 H]glycine but to a lesser extent than the Golgi neurons. It was also confirmed that under comparable conditions Golgi cells transport [ 3 H]GABA. Kinetic studies utilizing the Golgi axon terminal-containing glomerulus particles showed that glycine is a weak non-competitive inhibitor of [ 3 H]GABA uptake (Ksub(i) over 600 μM vs the Ksub(t) of about 20 μM) and that GABA is an even weaker inhibitor of [ 3 H]glycine uptake. (Auth.)

Lactate, Glucose and Oxygen Uptake in Human Brain During Recovery from Maximal Exercise

DEFF Research Database (Denmark)

Kojiro, I.; Schmalbruch, I.K.; Quistorff, B.

1999-01-01

Skeletal muscle, brain lactate uptake, brain oxygen uptake, energy metabolism, brain glucose uptake......Skeletal muscle, brain lactate uptake, brain oxygen uptake, energy metabolism, brain glucose uptake...

A biophysical approach using water deficit factor for daily estimations of evapotranspiration and CO2 uptake in Mediterranean environments

Directory of Open Access Journals (Sweden)

D. Helman

2017-09-01

Full Text Available Estimations of ecosystem-level evapotranspiration (ET and CO2 uptake in water-limited environments are scarce and scaling up ground-level measurements is not straightforward. A biophysical approach using remote sensing (RS and meteorological data (RS–Met is adjusted to extreme high-energy water-limited Mediterranean ecosystems that suffer from continuous stress conditions to provide daily estimations of ET and CO2 uptake (measured as gross primary production, GPP at a spatial resolution of 250 m. The RS–Met was adjusted using a seasonal water deficit factor (fWD based on daily rainfall, temperature and radiation data. We validated our adjusted RS–Met with eddy covariance flux measurements using a newly developed mobile lab system and the single active FLUXNET station operating in this region (Yatir pine forest station at a total of seven forest and non-forest sites across a climatic transect in Israel (280–770 mm yr−1. RS–Met was also compared to the satellite-borne MODIS-based ET and GPP products (MOD16 and MOD17, respectively at these sites.Results show that the inclusion of the fWD significantly improved the model, with R =  0.64–0.91 for the ET-adjusted model (compared to 0.05–0.80 for the unadjusted model and R =  0.72–0.92 for the adjusted GPP model (compared to R =  0.56–0.90 of the non-adjusted model. The RS–Met (with the fWD successfully tracked observed changes in ET and GPP between dry and wet seasons across the sites. ET and GPP estimates from the adjusted RS–Met also agreed well with eddy covariance estimates on an annual timescale at the FLUXNET station of Yatir (266 ± 61 vs. 257 ± 58 mm yr−1 and 765 ± 112 vs. 748 ± 124 gC m−2 yr−1 for ET and GPP, respectively. Comparison with MODIS products showed consistently lower estimates from the MODIS-based models, particularly at the forest sites. Using the adjusted RS–Met, we show that afforestation

Physiological FDG uptake in the ovaries after hysterectomy

International Nuclear Information System (INIS)

Nishizawa, Sadahiko; Inubushi, Masayuki; Ozawa, Fukujiro; Kido, Aki; Okada, Hiroyuki

2007-01-01

It is known that focal 18 F-fluorodeoxyglucose (FDG) uptake is physiologically seen in the ovaries and uterus of premenopausal women in correlation with the menstrual cycle, which may cause false-positive diagnoses on the images of FDG positron emission tomography (PET). The objective of this study was to clarify whether women of reproductive age after hysterectomy whose ovaries were preserved, also showed physiological ovarian FDG uptake. We reviewed 26 women after hysterectomy (age 51.1±5.0 years), who underwent annual cancer screening, including FDG-PET and pelvic magnetic resonance (MR) imaging, three times. Seven women (age 45.9±5.8 years, range 34-52 years) had at least one ovary, showing changes in its appearance including the size and number of follicles on MR images each year, which suggested that the ovary was functioning. Four of the seven women showed focal FDG uptake (standardized uptake value 4.2±1.1) that corresponded to the normal ovaries on five PET examinations. Another group of 19 women (age 53.1±3.1 years, range 47-59 years) who had small ovaries without changes on MR images each year did not show FDG uptake in the ovaries. Physiological FDG uptake observed in the ovaries of women of reproductive age even after hysterectomy is reasonably common. As it is not easy to determine the hormonal cycle in these women, it is essential to correlate focal FDG uptake in the pelvis with anatomical and morphological findings on MR images to avoid false-positive diagnoses. (author)

Heavy metal uptake of Geosiphon pyriforme

Energy Technology Data Exchange (ETDEWEB)

Scheloske, Stefan E-mail: stefan.scheloske@mpi-hd.mpg.de; Maetz, Mischa; Schuessler, Arthur

2001-07-01

Geosiphon pyriforme represents the only known endosymbiosis between a fungus, belonging to the arbuscular mycorrhizal (AM) fungi, and cyanobacteria (blue-green algae). Therefore we use Geosiphon as a model system for the widespread AM symbiosis and try to answer some basic questions regarding heavy metal uptake or resistance of AM fungi. We present quantitative micro-PIXE measurements of a set of heavy metals (Cu, Cd, Tl, Pb) taken up by Geosiphon-cells. The uptake is studied as a function of the metal concentration in the nutrient solution and of the time Geosiphon spent in the heavy metal enriched medium. The measured heavy metal concentrations range from several ppm to some hundred ppm. Also the influence of the heavy metal uptake on the nutrition transfer of other elements will be discussed.

Selective uptake of manganese in seawater by hybrid microcapsules

International Nuclear Information System (INIS)

Kuzumaki, Takenori; Yan, Wu; Mimura, Hitoshi; Niibori, Yuichi

2008-01-01

The selective separation and recovery of low concentrated elements in seawater are very important subjects for the advancement of environmental monitoring. Selective uptake of manganese from seawater was carried out by using two kinds of microcapsules (MCs) including activated carbon (AC) and insoluble tannin (T). The adsorbents, AC and T, having affinity for manganese, were enclosed into MCs (ACMS, TMC) by sol-gel method using matrices of biopolymer (calcium alginate gel polymer, CaALG). The uptake properties and selectivity of Mn 2+ (1 ppm) for MCs were examined by batch method. Relatively large uptake percentages of Mn 2+ above 80% were obtained within 1 h, and the uptake percentage above 80% was kept at pH 3-6. The uptake order was found to be T, AC, CaALG > ACMC, TMC. The uptake of Mn 2+ decreased with increasing Na + ion concentration. This tendency depends on the swelling property of CaALG; it tends to solate in the presence of highly concentrated Na + ions. The manganese ions were adsorbed on CaALG, ACMC and TMC from seawater containing 1,000 ppm Mn 2+ . ACMC and TMC had selectivity to Mn 2+ , and, especially, the matrices of CaALG also had an excellent uptake and selectivity properties. (author)

Selenium Uptake and Volatilization by Marine Algae

Science.gov (United States)

Luxem, Katja E.; Vriens, Bas; Wagner, Bettina; Behra, Renata; Winkel, Lenny H. E.

2015-04-01

Selenium (Se) is an essential trace nutrient for humans. An estimated one half to one billion people worldwide suffer from Se deficiency, which is due to low concentrations and bioavailability of Se in soils where crops are grown. It has been hypothesized that more than half of the atmospheric Se deposition to soils is derived from the marine system, where microorganisms methylate and volatilize Se. Based on model results from the late 1980s, the atmospheric flux of these biogenic volatile Se compounds is around 9 Gt/year, with two thirds coming from the marine biosphere. Algae, fungi, and bacteria are known to methylate Se. Although algal Se uptake, metabolism, and methylation influence the speciation and bioavailability of Se in the oceans, these processes have not been quantified under environmentally relevant conditions and are likely to differ among organisms. Therefore, we are investigating the uptake and methylation of the two main inorganic Se species (selenate and selenite) by three globally relevant microalgae: Phaeocystis globosa, the coccolithophorid Emiliania huxleyi, and the diatom Thalassiosira oceanica. Selenium uptake and methylation were quantified in a batch experiment, where parallel gas-tight microcosms in a climate chamber were coupled to a gas-trapping system. For E. huxleyi, selenite uptake was strongly dependent on aqueous phosphate concentrations, which agrees with prior evidence that selenite uptake by phosphate transporters is a significant Se source for marine algae. Selenate uptake was much lower than selenite uptake. The most important volatile Se compounds produced were dimethyl selenide, dimethyl diselenide, and dimethyl selenyl sulfide. Production rates of volatile Se species were larger with increasing intracellular Se concentration and in the decline phase of the alga. Similar experiments are being carried out with P. globosa and T. oceanica. Our results indicate that marine algae are important for the global cycling of Se

[Long-Term Inhibition of FNA on Aerobic Phosphate Uptake and Variation of Phosphorus Uptake Properties of the Sludge].

Science.gov (United States)

Ma, Juan; Li, Lu; Yu, Xiao-jun; Sun, Lei-jun; Sun, Hong-wei; Chen, Yong-zhi

2015-10-01

An alternating anaerobic/oxic ( An/O) sequencing batch reactor (SBR) was employed to investigate the long-term inhibitory effect of free nitrous acid (FNA) on aerobic phosphorus uptake performance and variation of phosphorus uptake properties of the sludge by adding nitrite. The reactor was started up under the condition of 21-23 degrees C. The results showed that FNA had no impact on phosphate release and uptake capacities of the sludge. However, the specific phosphate release/uptake rates was found to be higher. As FNA concentration (measure by HNO2-N) was lower than 0.53 x 10(-3) mg x L(-1), phosphorus removal efficiency of the system was higher than 96.9%. When the FNA concentration was increased to 0.99 x 10(-3) mg x L(-1), 1.46 x 10(-3) mg x L(-1) and 1.94 x 10(-3) mg x L(-1), the phosphorus removal performance deteriorated rapidly. The phosphorus removal efficiency was recovered to 64.42%, 67.33% and 44.14% after 50, 12 and 30 days, respectively, which implied the deterioration of phosphorus removal performance caused by FNA inhibition could be recovered and long-term acclimation could shorten the recovery process. Notably, increasing nitrite consumption appeared during aerobic phase with the concentration of FNA below 1.46 x 10(-3) mg x L(-1). It was also observed that the phosphorus uptake properties of the sludge varied after long-term inhibition. Nitrate and nitrite type anoxic phosphorus uptake capacity was increased by 3.35 and 3.86 times, respectively, suggesting long-term dosing FNA may facilitate the denitrifying of polyphosphate in organisms utilizing nitrite as electron acceptor. Moreover, long-term acclimation favored sludge settling.

Uptake of heavy metals by plants from airborne deposition and polluted soils

Directory of Open Access Journals (Sweden)

T. YLÄRANTA

2008-12-01

Full Text Available The concentrations of sulphur, zinc, copper, lead and cadmium in spring wheat grain and straw, Italian rye grass, timothy and lettuce were studied in a three-year field experiment conducted in southern Finland near a copper-nickel smelter and at nonpolluted control sites. A pot experiment with copper- and nickel-contaminated soils and with a nonpolluted soil as the control was conducted to determine the copper and nickel concentrations in soils phytotoxic for plants. Forty, 200 or 1000 mg of copper or nickel as cloride was added to 2 litres of soil. The nickel and copper concentrations in the shoots of oats were measured. The zinc, copper, lead, cadmium and nickel concentrations varied between different plant species and also between experimental years. Near the smelter, the uptake of nickel by different plant species was very effective, as was copper uptake by lettuce, timothy and Italian rye grass. The same applied to the zinc and cadmium uptake of plants grown on plots. Nickel, cadmium and copper were easily accumulated by plants from air deposition. In the pot experiment, high nickel concentrations in soil were more phytotoxic for oats than were high copper concentrations. In acidic soil, nickel and copper concentrations lower than 20 and 100 mg/kg of soil, respectively, decreased the dry matter yield of oats shoots. Liming clearly decreased copper and nickel phytotoxity. In the most highly contaminated soil, the addition of Cu 20 mg/kg of soil decreased the yield of oats shoots.;

[3H]opipramol labels a novel binding site and sigma receptors in rat brain membranes

International Nuclear Information System (INIS)

Ferris, C.D.; Hirsch, D.J.; Brooks, B.P.; Snowman, A.M.; Snyder, S.H.

1991-01-01

Opipramol (OP), a clinically effective antidepressant with a tricyclic structure, is inactive as an inhibitor of biogenic amine uptake. [ 3 H]Opipramol binds saturably to rat brain membranes (apparent KD = 4 nM, Bmax = 3 pmol/mg of protein). [ 3 H]Opipramol binding can be differentiated into haloperidol-sensitive and -resistant components, with Ki values for haloperidol of 1 nM (Bmax = 1 pmol/mg of protein) and 350 nM (Bmax = 1.9 pmol/mg of protein), respectively. The drug specificity of the haloperidol-sensitive component is the same as that of sigma receptors labeled with (+)-[ 3 H]3-(3-hydroxyphenyl)-N-(1-propyl)piperdine. The haloperidol-resistant component does not correspond to any known neurotransmitter receptor or uptake recognition site. It displays high affinity for phenothiazines and related structures such as perphenazine, clopenthixol, and flupenthixol, whose potencies are comparable to that of opipramol. Because certain of these drugs are more potent at the haloperidol-resistant opipramol site than in exerting any other action, it is possible that this opipramol-selective site may mediate their therapeutic effects

Gallium-67 uptake in meningeal sarcoidosis

International Nuclear Information System (INIS)

Ayres, J.G.; Hicks, B.H.; Maisey, M.N.

1986-01-01

A case of sarcoidosis limited to the central nervous system is described in which the diagnosis was suggested by high Ga-67 uptake in the cranial and spinal meninges. The diagnosis was confirmed by meningeal biopsy. Treatment with oral corticosteroids resulted in clinical improvement and marked reduction in Ga-67 uptake in the meninges. This is the first reported case of the central nervous system sarcoid diagnosed by Ga-67 imaging

The uptake of radionuclides by plants

International Nuclear Information System (INIS)

Cawse, P.A.; Turner, G.S.

1982-02-01

A review of the literature, since 1970, on the research into the uptake of radionuclides by plants, with references to earlier soil and plant studies on the fate of nuclear weapons fallout. Experimental data on the uptake of plutonium isotopes, americium 241, cesium 137, radium 226, curium 244 and neptunium 237 and details of the chemical form of the radionuclide, soil type and plant growth period are tabulated. (U.K.)

Thyroid uptake of I-131 during anti-thyroid drug treatment

International Nuclear Information System (INIS)

Hoque, M.; Alam, F.; Haque, F.S.; Karim, M.A.; Fariduddin, M.

2004-01-01

Hyperthyroidism is a global ailment and its treatment is very promising either by ant-thyroid drug or by radioiodine. Iodine-131 uptake test is very important for evaluation of hyperthyroid in respect to its therapy and to exclude thyroiditis. This study was performed to observe the thyroid uptake pattern during intake of anti-thyroid medicine and workout the possibility to start I-131 therapy just after withdraw of antithyroid drug without waiting few days. In this study total 252 patient's I-131 uptake test is performed. Among the patient 135 (53.57%) were female, 117 (64.43%) were male. All this patients were hyperthyroid both clinically and biochemically. Thyroid uptake was taken to all patients at 24 hours after oral administration of 5 to 10 micro-curie of I -131. Uptake was taken by an uptake system and recorded as percentage uptake. These patients are grouped into three categories. Group-A-newly diagnosed cases, who have not taken antithyroid drug or I-131 therapy, there were 82 patients in this group, and their mean uptake was 37.12 ±18.5%. Group B - this group of patients were studied during intake of antithyroid medicine, there were 130 patients in this group and their mean uptake was 34.34±16.0%. Group-B patients were further divided in two sub-groups, patients having antithyroid drug for 1 to 3 weeks (group-B 1), group B1 have mean uptake 37±21% and those were taking antithyroid for 3 weeks to 2 years (group-B2), group B2 have uptake 34.34±20%. Group C- these patients are taken from those patients who had withdrawn antithyroid drug for 3 days to 3 months, there were 40 such patients. Group C further divided into two sub-group, group-C1 (stopped for 3-10 days) and group C2 (stopped for 11 days to 3 months). Group C1 had mean uptake 38±16% and group C2 had mean uptake 35±19%. From this study it is observed that Iodine-131 uptake percentage of untreated hyperthyroid; during antithyroid drug treatment and after withdraw of antithyroid drug almost

Retinal uptake and release of (/sup 3/H)DABA

Energy Technology Data Exchange (ETDEWEB)

Bauer, B; Ehinger, B [Lund Univ. (Sweden)

1978-03-01

The uptake of (/sup 3/H)DABA was studied in rat, guinea-pig and cat retinas in vivo and in rabbit retinas both in vivo and in vitro by autoradiography. (/sup 3/H)DABA was preferentially accumulated by a type of amacrine cell but after brief incubation or shortly after intravitreal injections there was not only a neuronal uptake but also a glial one. In guinea-pigs the glial labelling in vivo was significant also after 4 hr. The glial uptake (rabbits) was found to be saturable and temperature dependent as expected for an active uptake mechanism. The Ksub(m) of DABA uptake was 2.11 x 10/sup -5/ m and Vsub(max) 2.38 x 10/sup -5/ mol/mg/min. GABA competitively inhibited the DABA uptake. The uptake was not statistically significantly influenced by OMEGA-amino acids such as glycine, ..beta..-alanine, ..cap alpha..-alanine or epsilon-aminocaproic acid. The effect of different stimuli on the spontaneous efflux of radioactivity from (/sup 3/H)DABA preloaded rabbit retinas was studied with (/sup 3/H)DABA localized to neurons. Light flashes evoked a small but not statistically significant increased release whereas 40mM-K/sup +/ evoked an immediate and large increase. Unlabelled DABA, GABA and ..beta..-alanine (10/sup -5/M) increased the spontaneous efflux of (/sup 3/H)DABA but not glycine. It is concluded that there is in the retina of rats, guinea-pigs, cats, and rabbits, a glial high affinity uptake mechanism in addition to the neuronal uptake. DABA seems to be transported by the same mechanism as GABA in both systems. The DABA seems to be better retained in neurons than in glia in rats, cats and rabbits, which allows it to be used as a neuronal marker.

Controls on seasonal patterns of maximum ecosystem carbon uptake and canopy-scale photosynthetic light response: contributions from both temperature and photoperiod.

Science.gov (United States)

Stoy, Paul C; Trowbridge, Amy M; Bauerle, William L

2014-02-01

Most models of photosynthetic activity assume that temperature is the dominant control over physiological processes. Recent studies have found, however, that photoperiod is a better descriptor than temperature of the seasonal variability of photosynthetic physiology at the leaf scale. Incorporating photoperiodic control into global models consequently improves their representation of the seasonality and magnitude of atmospheric CO2 concentration. The role of photoperiod versus that of temperature in controlling the seasonal variability of photosynthetic function at the canopy scale remains unexplored. We quantified the seasonal variability of ecosystem-level light response curves using nearly 400 site years of eddy covariance data from over eighty Free Fair-Use sites in the FLUXNET database. Model parameters describing maximum canopy CO2 uptake and the initial slope of the light response curve peaked after peak temperature in about 2/3 of site years examined, emphasizing the important role of temperature in controlling seasonal photosynthetic function. Akaike's Information Criterion analyses indicated that photoperiod should be included in models of seasonal parameter variability in over 90% of the site years investigated here, demonstrating that photoperiod also plays an important role in controlling seasonal photosynthetic function. We also performed a Granger causality analysis on both gross ecosystem productivity (GEP) and GEP normalized by photosynthetic photon flux density (GEP n ). While photoperiod Granger-caused GEP and GEP n in 99 and 92% of all site years, respectively, air temperature Granger-caused GEP in a mere 32% of site years but Granger-caused GEP n in 81% of all site years. Results demonstrate that incorporating photoperiod may be a logical step toward improving models of ecosystem carbon uptake, but not at the expense of including enzyme kinetic-based temperature constraints on canopy-scale photosynthesis.

Uptake of thallium-201 in enlarged thyroid glands. Concise communication

International Nuclear Information System (INIS)

Fukuchi, M.; Kido, A.; Hyodo, K.; Tachibana, K.; Onoue, K.; Morita, T.; Nagai, K.

1979-01-01

We have investigated the thyroid uptake of Tl-201 in 37 patients with various types of goiter, and in six with normal thyroids. Significant thallium uptake was found in all cases in which there was thyroid enlargement, including Graves' disease, toxic thyroid nodule, primary hypothyroidism, simple goiter, Hashimoto's disease, thyroid carcinoma, and thyroid adenoma. If goiter was absent, however, there was no demonstrable uptake - e.g., in secondary hypothyroidism, subacute thyroiditis, and the normal controls. Thallium uptake did not correlate with thyroid function tests such as BMR, T 3 -RU, T 3 , T 4 , TSH, antithyroid antibodies, or the 24-hr I-131 uptake. In 23 patients with diffuse goiter, on the other hand, maximum Tl-201 uptake correlated well with thyroid weight: r = 0.836 (p < 0.001); y = 0.02 x + 0.06

Modeling uptake kinetics of cadmium by field-grown lettuce

Energy Technology Data Exchange (ETDEWEB)

Chen Weiping [Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521 (United States)], E-mail: chenweip@yahoo.com.cn; Li Lianqing [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095 (China); Chang, Andrew C.; Wu Laosheng [Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521 (United States); Kwon, Soon-Ik [Agricultural Environmental and Ecology Division, National Institute of Agricultural Science and Technology, Suwon 441-707 (Korea, Republic of); Bottoms, Rick [Desert Research and Extension Center, 1004 East Holton Road, El Centro, CA 92243 (United States)

2008-03-15

Cadmium uptake by field grown Romaine lettuce treated with P-fertilizers of different Cd levels was investigated over an entire growing season. Results indicated that the rate of Cd uptake at a given time of the season can be satisfactorily described by the Michaelis-Menten kinetics, that is, plant uptake increases as the Cd concentration in soil solution increases, and it gradually approaches a saturation level. However, the rate constant of the Michaelis-Menten kinetics changes over the growing season. Under a given soil Cd level, the cadmium content in plant tissue decreases exponentially with time. To account for the dynamic nature of Cd uptake, a kinetic model integrating the time factor was developed to simulate Cd plant uptake over the growing season: C{sub Plant} = C{sub Solution} . PUF{sub max} . exp[-b . t], where C{sub Plant} and C{sub Solution} refer to the Cd content in plant tissue and soil solution, respectively, PUF{sub max} and b are kinetic constants. - A kinetic model was developed to evaluate the uptake of Cd under field conditions.

Modeling uptake kinetics of cadmium by field-grown lettuce

International Nuclear Information System (INIS)

Chen Weiping; Li Lianqing; Chang, Andrew C.; Wu Laosheng; Kwon, Soon-Ik; Bottoms, Rick

2008-01-01

Cadmium uptake by field grown Romaine lettuce treated with P-fertilizers of different Cd levels was investigated over an entire growing season. Results indicated that the rate of Cd uptake at a given time of the season can be satisfactorily described by the Michaelis-Menten kinetics, that is, plant uptake increases as the Cd concentration in soil solution increases, and it gradually approaches a saturation level. However, the rate constant of the Michaelis-Menten kinetics changes over the growing season. Under a given soil Cd level, the cadmium content in plant tissue decreases exponentially with time. To account for the dynamic nature of Cd uptake, a kinetic model integrating the time factor was developed to simulate Cd plant uptake over the growing season: C Plant = C Solution . PUF max . exp[-b . t], where C Plant and C Solution refer to the Cd content in plant tissue and soil solution, respectively, PUF max and b are kinetic constants. - A kinetic model was developed to evaluate the uptake of Cd under field conditions

A kinetic study of cation release from a mixed mineral assemblage: implications for determination of uranium uptake

International Nuclear Information System (INIS)

Fenton, B.R.; Waite, T.D.