File list: InP.Neu.10.AllAg.Forebrain [Chip-atlas[Archive

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File list: InP.Neu.50.AllAg.Forebrain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Neu.50.AllAg.Forebrain mm9 Input control Neural Forebrain SRX377679,SRX377675,S...RX377677,SRX377673,SRX669236,SRX377671 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Neu.50.AllAg.Forebrain.bed ...

Microglia Modulate Wiring of the Embryonic Forebrain

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Paola Squarzoni

2014-09-01

Full Text Available Dysfunction of microglia, the tissue macrophages of the brain, has been associated with the etiology of several neuropsychiatric disorders. Consistently, microglia have been shown to regulate neurogenesis and synaptic maturation at perinatal and postnatal stages. However, microglia invade the brain during mid-embryogenesis and thus could play an earlier prenatal role. Here, we show that embryonic microglia, which display a transiently uneven distribution, regulate the wiring of forebrain circuits. Using multiple mouse models, including cell-depletion approaches and cx3cr1−/−, CR3−/−, and DAP12−/− mutants, we find that perturbing microglial activity affects the outgrowth of dopaminergic axons in the forebrain and the laminar positioning of subsets of neocortical interneurons. Since defects in both dopamine innervation and cortical networks have been linked to neuropsychiatric diseases, our study provides insights into how microglial dysfunction can impact forebrain connectivity and reveals roles for immune cells during normal assembly of brain circuits.

Unilateral lateral entorhinal inactivation impairs memory expression in trace eyeblink conditioning.

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Stephanie E Tanninen

Full Text Available Memory in trace eyeblink conditioning is mediated by an inter-connected network that involves the hippocampus (HPC, several neocortical regions, and the cerebellum. This network reorganizes after learning as the center of the network shifts from the HPC to the medial prefrontal cortex (mPFC. Despite the network reorganization, the lateral entorhinal cortex (LEC plays a stable role in expressing recently acquired HPC-dependent memory as well as remotely acquired mPFC-dependent memory. Entorhinal involvement in recent memory expression may be attributed to its previously proposed interactions with the HPC. In contrast, it remains unknown how the LEC participates in memory expression after the network disengages from the HPC. The present study tested the possibility that the LEC and mPFC functionally interact during remote memory expression by examining the impact of pharmacological inactivation of the LEC in one hemisphere and the mPFC in the contralateral hemisphere on memory expression in rats. Memory expression one day and one month after learning was significantly impaired after LEC-mPFC inactivation; however, the degree of impairment was comparable to that after unilateral LEC inactivation. Unilateral mPFC inactivation had no effect on recent or remote memory expression. These results suggest that the integrity of the LEC in both hemispheres is necessary for memory expression. Functional interactions between the LEC and mPFC should therefore be tested with an alternative design.

Functional Connectome Analysis of Dopamine Neuron Glutamatergic Connections in Forebrain Regions.

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Mingote, Susana; Chuhma, Nao; Kusnoor, Sheila V; Field, Bianca; Deutch, Ariel Y; Rayport, Stephen

2015-12-09

capable of glutamate cotransmission. With conditional expression of channelrhodopsin in dopamine neurons, we systematically explored dopamine neuron connections in the forebrain and identified regionally specific dopamine neuron excitatory connections. Establishing that only a subset of forebrain regions receive excitatory connections from dopamine neurons will help to determine the function of dopamine neuron glutamate cotransmission, which likely involves transmission of precise temporal signals and enhancement of the dynamic range of dopamine neuron signals. Copyright © 2015 the authors 0270-6474/15/3516259-13$15.00/0.

Forebrain Mechanisms of Nociception and Pain: Analysis through Imaging

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Casey, Kenneth L.

1999-07-01

Pain is a unified experience composed of interacting discriminative, affective-motivational, and cognitive components, each of which is mediated and modulated through forebrain mechanisms acting at spinal, brainstem, and cerebral levels. The size of the human forebrain in relation to the spinal cord gives anatomical emphasis to forebrain control over nociceptive processing. Human forebrain pathology can cause pain without the activation of nociceptors. Functional imaging of the normal human brain with positron emission tomography (PET) shows synaptically induced increases in regional cerebral blood flow (rCBF) in several regions specifically during pain. We have examined the variables of gender, type of noxious stimulus, and the origin of nociceptive input as potential determinants of the pattern and intensity of rCBF responses. The structures most consistently activated across genders and during contact heat pain, cold pain, cutaneous laser pain or intramuscular pain were the contralateral insula and anterior cingulate cortex, the bilateral thalamus and premotor cortex, and the cerebellar vermis. These regions are commonly activated in PET studies of pain conducted by other investigators, and the intensity of the brain rCBF response correlates parametrically with perceived pain intensity. To complement the human studies, we developed an animal model for investigating stimulus-induced rCBF responses in the rat. In accord with behavioral measures and the results of human PET, there is a progressive and selective activation of somatosensory and limbic system structures in the brain and brainstem following the subcutaneous injection of formalin. The animal model and human PET studies should be mutually reinforcing and thus facilitate progress in understanding forebrain mechanisms of normal and pathological pain.

Cholinergic basal forebrain structures are not essential for mediation of the arousing action of glutamate.

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Lelkes, Zoltán; Abdurakhmanova, Shamsiiat; Porkka-Heiskanen, Tarja

2017-09-18

The cholinergic basal forebrain contributes to cortical activation and receives rich innervations from the ascending activating system. It is involved in the mediation of the arousing actions of noradrenaline and histamine. Glutamatergic stimulation in the basal forebrain results in cortical acetylcholine release and suppression of sleep. However, it is not known to what extent the cholinergic versus non-cholinergic basal forebrain projection neurones contribute to the arousing action of glutamate. To clarify this question, we administered N-methyl-D-aspartate (NMDA), a glutamate agonist, into the basal forebrain in intact rats and after destruction of the cholinergic cells in the basal forebrain with 192 immunoglobulin (Ig)G-saporin. In eight Han-Wistar rats with implanted electroencephalogram/electromyogram (EEG/EMG) electrodes and guide cannulas for microdialysis probes, 0.23 μg 192 IgG-saporin was administered into the basal forebrain, while the eight control animals received artificial cerebrospinal fluid. Two weeks later, a microdialysis probe targeted into the basal forebrain was perfused with cerebrospinal fluid on the baseline day and for 3 h with 0.3 mmNMDA on the subsequent day. Sleep-wake activity was recorded for 24 h on both days. NMDA exhibited a robust arousing effect in both the intact and the lesioned rats. Wakefulness was increased and both non-REM and REM sleep were decreased significantly during the 3-h NMDA perfusion. Destruction of the basal forebrain cholinergic neurones did not abolish the wake-enhancing action of NMDA. Thus, the cholinergic basal forebrain structures are not essential for the mediation of the arousing action of glutamate. © 2017 European Sleep Research Society.

Inactivating the infralimbic but not prelimbic medial prefrontal cortex facilitates the extinction of appetitive Pavlovian conditioning in Long-Evans rats.

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Mendoza, J; Sanio, C; Chaudhri, N

2015-02-01

The infralimbic medial prefrontal cortex (IL) has been posited as a common node in distinct neural circuits that mediate the extinction of appetitive and aversive conditioning. However, appetitive extinction is typically assessed using instrumental conditioning procedures, whereas the extinction of aversive conditioning is customarily studied using Pavlovian assays. The role of the IL in the extinction of appetitive Pavlovian conditioning remains underexplored. We investigated the involvement of the IL and prelimbic medial prefrontal cortex (PrL) in appetitive extinction in Pavlovian and instrumental conditioning assays in male, Long-Evans rats. Following acquisition, a gamma-aminobutyric acid agonist solution (0.03 nmol muscimol; 0.3 nmol baclofen; 0.3 μl/side) was bilaterally microinfused into the IL or PrL to pharmacologically inactivate each region before the first extinction session. Compared to saline, PrL inactivation did not affect the acquisition of extinction or the recall of extinction memory 24-h later. IL inactivation caused a more rapid extinction of Pavlovian conditioning, but had no effect on the extinction of instrumental conditioning or extinction recall. IL inactivation during a Pavlovian conditioning session in which conditioned stimulus (CS) trials were paired with sucrose did not affect CS-elicited behaviour, but increased responding during intervals that did not contain the CS. The same manipulation did not impact lever pressing for sucrose. These findings suggest that the IL may normally maintain Pavlovian conditioned responding when an anticipated appetitive CS is unexpectedly withheld, and that this region has distinct roles in the expression of Pavlovian conditioning when an appetitive unconditioned stimulus is either presented or omitted. Copyright © 2014 Elsevier Inc. All rights reserved.

Spore inactivation and DPA release in Alicyclobacillus acidoterrestris under different stress conditions.

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Bevilacqua, Antonio; Ciuffreda, Emanuela; Sinigaglia, Milena; Corbo, Maria Rosaria

2015-04-01

This paper reports on the inactivation of spores of 5 strains of Alicyclobacillus acidoterrestris under different stress conditions (acidic and alkaline pH, high temperature, addition of lysozyme, hydrogen peroxide and p-coumaric acid). The research was divided into two different steps; first, each stress was studied alone, thus pointing out a partial uncoupling between spore inactivation and DPA release, as H2O2 reduced spore level below the detection but it did not cause the release of DPA. A partial correlation was found only for acidic and alkaline pH. 2nd step was focused on the combination of pH, temperature and H2O2 through a factorial design; experiments were performed on both fresh and 4 month-old spores and pinpointed a different trend for DPA release as a function of spore age. Copyright © 2014 Elsevier Ltd. All rights reserved.

Role of Shp2 in forebrain neurons in regulating metabolic and cardiovascular functions and responses to leptin.

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do Carmo, J M; da Silva, A A; Sessums, P O; Ebaady, S H; Pace, B R; Rushing, J S; Davis, M T; Hall, J E

2014-06-01

We examined whether deficiency of Src homology 2 containing phosphatase (Shp2) signaling in forebrain neurons alters metabolic and cardiovascular regulation under various conditions and if it attenuates the anorexic and cardiovascular effects of leptin. We also tested whether forebrain Shp2 deficiency alters blood pressure (BP) and heart rate (HR) responses to acute stress. Forebrain Shp2(-/-) mice were generated by crossing Shp2(flox/flox) mice with CamKIIα-cre mice. At 22-24 weeks of age, the mice were instrumented for telemetry for measurement of BP, HR and body temperature (BT). Oxygen consumption (VO2), energy expenditure and motor activity were monitored by indirect calorimetry. Shp2/CamKIIα-cre mice were heavier (46±3 vs 32±1 g), hyperglycemic, hyperleptinemic, hyperinsulinemic and hyperphagic compared to Shp2(flox/flox) control mice. Shp2/CamKIIα-cre mice exhibited reduced food intake responses to fasting/refeeding and impaired regulation of BT when exposed to 15 and 30 °C ambient temperatures. Despite being obese and having many features of metabolic syndrome, Shp2/CamKIIα-cre mice had similar daily average BP and HR compared to Shp2(flox/flox) mice (112±2 vs 113±1 mm Hg and 595±34 vs 650±40 b.p.m.), but exhibited increased BP and HR responses to cold exposure and acute air-jet stress test. Leptin's ability to reduce food intake and to raise BP were markedly attenuated in Shp2/CamKIIα-cre mice. These results suggest that forebrain Shp2 signaling regulates food intake, appetite responses to caloric deprivation and thermogenic control of body temperature during variations in ambient temperature. Deficiency of Shp2 signaling in the forebrain is associated with augmented cardiovascular responses to cold and acute stress but attenuated BP responses to leptin.

Transcriptional maturation of the mouse auditory forebrain.

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Hackett, Troy A; Guo, Yan; Clause, Amanda; Hackett, Nicholas J; Garbett, Krassimira; Zhang, Pan; Polley, Daniel B; Mirnics, Karoly

2015-08-14

The maturation of the brain involves the coordinated expression of thousands of genes, proteins and regulatory elements over time. In sensory pathways, gene expression profiles are modified by age and sensory experience in a manner that differs between brain regions and cell types. In the auditory system of altricial animals, neuronal activity increases markedly after the opening of the ear canals, initiating events that culminate in the maturation of auditory circuitry in the brain. This window provides a unique opportunity to study how gene expression patterns are modified by the onset of sensory experience through maturity. As a tool for capturing these features, next-generation sequencing of total RNA (RNAseq) has tremendous utility, because the entire transcriptome can be screened to index expression of any gene. To date, whole transcriptome profiles have not been generated for any central auditory structure in any species at any age. In the present study, RNAseq was used to profile two regions of the mouse auditory forebrain (A1, primary auditory cortex; MG, medial geniculate) at key stages of postnatal development (P7, P14, P21, adult) before and after the onset of hearing (~P12). Hierarchical clustering, differential expression, and functional geneset enrichment analyses (GSEA) were used to profile the expression patterns of all genes. Selected genesets related to neurotransmission, developmental plasticity, critical periods and brain structure were highlighted. An accessible repository of the entire dataset was also constructed that permits extraction and screening of all data from the global through single-gene levels. To our knowledge, this is the first whole transcriptome sequencing study of the forebrain of any mammalian sensory system. Although the data are most relevant for the auditory system, they are generally applicable to forebrain structures in the visual and somatosensory systems, as well. The main findings were: (1) Global gene expression

A forebrain atlas of the lizard Gekko gecko.

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Smeets, W J; Hoogland, P V; Lohman, A H

1986-12-01

An atlas of the forebrain of the lizard Gekko gecko has been provided, which will serve as the basis for subsequent experimental tracing and immunohistochemical studies. Apart from a strongly developed medial cortex and septal area, the Tokay gecko shows all the main features of the forebrain of the lacertid-type lizards. When its convenience as an experimental animal is also taken into account, this species seems to be very suitable for studying the limbic system in reptiles. The atlas comprises topographical reconstructions of the telencephalon and diencephalon and a series of transverse sections of which the levels have been indicated in the reconstructions. The results obtained in the Gekko are briefly compared with those found in other lizards studied.

Adult forebrain NMDA receptors gate social motivation and social memory.

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Jacobs, Stephanie; Tsien, Joe Z

2017-02-01

Motivation to engage in social interaction is critical to ensure normal social behaviors, whereas dysregulation in social motivation can contribute to psychiatric diseases such as schizophrenia, autism, social anxiety disorders and post-traumatic stress disorder (PTSD). While dopamine is well known to regulate motivation, its downstream targets are poorly understood. Given the fact that the dopamine 1 (D1) receptors are often physically coupled with the NMDA receptors, we hypothesize that the NMDA receptor activity in the adult forebrain principal neurons are crucial not only for learning and memory, but also for the proper gating of social motivation. Here, we tested this hypothesis by examining sociability and social memory in inducible forebrain-specific NR1 knockout mice. These mice are ideal for exploring the role of the NR1 subunit in social behavior because the NR1 subunit can be selectively knocked out after the critical developmental period, in which NR1 is required for normal development. We found that the inducible deletion of the NMDA receptors prior to behavioral assays impaired, not only object and social recognition memory tests, but also resulted in profound deficits in social motivation. Mice with ablated NR1 subunits in the forebrain demonstrated significant decreases in sociability compared to their wild type counterparts. These results suggest that in addition to its crucial role in learning and memory, the NMDA receptors in the adult forebrain principal neurons gate social motivation, independent of neuronal development. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of heavy ions on rabbit tissues: damage to the forebrain

International Nuclear Information System (INIS)

Cox, A.B.; Keng, P.C.; Lee, A.C.; Lett, J.T.

1982-01-01

As part of a study of progressive radiation effects in normal tissues, the forebrains of New Zealand white rabbits (Oryctolagus cuniculus) (about 6 weeks old) were irradiated locally with single acute doses of 60 Co γ-photons (LETsub(infinity)=0.3 keV/μm), Ne ions (LETsub(infinity)=35+-3 keV/μm) or Ar ions (LETsub(infinity)=90+-5 keV/μm). Other rabbits received fractionated doses of 60 Co γ-photons according to a standard radiotherapeutic protocol. Irradiated rabbits and appropriately aged controls were sacrificed at selected intervals, and whole sagittal sections of their brains were examined for pathological changes. Forebrain damage was scored with subjective indices based on histological differences between the anterior (irradiated) and posterior (unirradiated) regions of the brain. Those indices ranged from zero (no apparent damage) to five (severe infarctions, etc.). At intermediate levels of forebrain damage, the relative biological effectiveness (r.b.e.) of each heavy ion was similar to that found for alopecia and cataractogenesis, and the early expression of the damage was also accelerated as the LETsub(infinity) increased. Late deterioration of the forebrain appeared also to be accelerated by increasing LETsub(infinity), although its accurate quantification was not possible because other priorities in the overall experimental design limited systematic sacrifice of the animals. (author)

Ablation of ferroptosis regulator glutathione peroxidase 4 in forebrain neurons promotes cognitive impairment and neurodegeneration

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William Sealy Hambright

2017-08-01

Full Text Available Synaptic loss and neuron death are the underlying cause of neurodegenerative diseases such as Alzheimer's disease (AD; however, the modalities of cell death in those diseases remain unclear. Ferroptosis, a newly identified oxidative cell death mechanism triggered by massive lipid peroxidation, is implicated in the degeneration of neurons populations such as spinal motor neurons and midbrain neurons. Here, we investigated whether neurons in forebrain regions (cerebral cortex and hippocampus that are severely afflicted in AD patients might be vulnerable to ferroptosis. To this end, we generated Gpx4BIKO mouse, a mouse model with conditional deletion in forebrain neurons of glutathione peroxidase 4 (Gpx4, a key regulator of ferroptosis, and showed that treatment with tamoxifen led to deletion of Gpx4 primarily in forebrain neurons of adult Gpx4BIKO mice. Starting at 12 weeks after tamoxifen treatment, Gpx4BIKO mice exhibited significant deficits in spatial learning and memory function versus Control mice as determined by the Morris water maze task. Further examinations revealed that the cognitively impaired Gpx4BIKO mice exhibited hippocampal neurodegeneration. Notably, markers associated with ferroptosis, such as elevated lipid peroxidation, ERK activation and augmented neuroinflammation, were observed in Gpx4BIKO mice. We also showed that Gpx4BIKO mice fed a diet deficient in vitamin E, a lipid soluble antioxidant with anti-ferroptosis activity, had an expedited rate of hippocampal neurodegeneration and behavior dysfunction, and that treatment with a small-molecule ferroptosis inhibitor ameliorated neurodegeneration in those mice. Taken together, our results indicate that forebrain neurons are susceptible to ferroptosis, suggesting that ferroptosis may be an important neurodegenerative mechanism in diseases such as AD. Keywords: Ferroptosis, Neurodegeneration, Cognitive impairment, Alzheimer's disease, Glutathione peroxidase 4, Transgenic mice

Ascending connections to the forebrain in the Tegu lizard.

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Lohman, A H; van Woerden-Verkley, I

1978-12-01

The ascending connections to the striatum and the cortex of the Tegu lizard, Tupinambis nigropunctatus, were studied by means of anterograde fiber degeneration and retrograde axonal transport. The striatum receives projections by way of the dorsal peduncle of the lateral forebrain bundle from four dorsal thalamic nuclei: nucleus rotundus, nucleus reuniens, the posterior part of the dorsal lateral geniculate nucleus and nucleus dorsomedialis. The former three nuclei project to circumscribed areas of the dorsal striatum, whereas nucleus dorsomedialis has a distribution to the whole dorsal striatum. Other sources of origin to the striatum are the mesencephalic reticular formation, substantia nigra and nucleus cerebelli lateralis. With the exception of the latter afferentation all these projections are ipsilateral. The ascending connections to the pallium originate for the major part from nucleus dorsolateralis anterior of the dorsal thalamus. The fibers course in both the medial forebrain bundle and the dorsal peduncle of the lateral forebrain bundle and terminate ipsilaterally in the middle of the molecular layer of the small-celled part of the mediodorsal cortex and bilaterally above the intermediate region of the dorsal cortex. The latter area is reached also by fibers from the septal area. The large-celled part of the mediodorsal cortex receives projections from nucleus raphes superior and the corpus mammillare.

Cellular localization of transforming growth factor-alpha mRNA in rat forebrain.

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Seroogy, K B; Lundgren, K H; Lee, D C; Guthrie, K M; Gall, C M

1993-05-01

The cellular localization of transforming growth factor-alpha (TGF alpha) mRNA in juvenile and adult rat forebrain was examined using in situ hybridization with a 35S-labeled cRNA probe. TGF alpha cRNA-labeled neuronal perikarya were distributed across many forebrain regions including the olfactory bulb, caudate-putamen, nucleus accumbens, olfactory tubercle, ventral pallidum, amygdala, hippocampal stratum granulosum and CA3 stratum pyramidale, and piriform, entorhinal, and retrosplenial cortices. TGF alpha cRNA-hybridizing cells were also localized to several thalamic nuclei and to the suprachiasmatic, dorsomedial, and ventromedial nuclei of the hypothalamus. In addition, labeled cells were present in regions of white matter including the corpus callosum, anterior commissure, internal and external capsules, optic tract, and lateral olfactory tract. Thus, both neurons and glia appear to synthesize TGF alpha in normal brain. Hybridization densities were greater in neuronal fields at 2 weeks of age compared with the adult, suggesting a role for TGF alpha in the development of several forebrain systems. Our results demonstrating the prominent and wide-spread expression of TGF alpha mRNA in forebrain, combined with the extremely low abundance of epidermal growth factor mRNA in brain, support the argument that TGF alpha is the principal endogenous ligand for the epidermal growth factor receptor in normal brain.

Medial forebrain bundle lesions fail to structurally and functionally disconnect the ventral tegmental area from many ipsilateral forebrain nuclei: implications for the neural substrate of brain stimulation reward.

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Simmons, J M; Ackermann, R F; Gallistel, C R

1998-10-15

Lesions in the medial forebrain bundle rostral to a stimulating electrode have variable effects on the rewarding efficacy of self-stimulation. We attempted to account for this variability by measuring the anatomical and functional effects of electrolytic lesions at the level of the lateral hypothalamus (LH) and by correlating these effects to postlesion changes in threshold pulse frequency (pps) for self-stimulation in the ventral tegmental area (VTA). We implanted True Blue in the VTA and compared cell labeling patterns in forebrain regions of intact and lesioned animals. We also compared stimulation-induced regional [14C]deoxyglucose (DG) accumulation patterns in the forebrains of intact and lesioned animals. As expected, postlesion threshold shifts varied: threshold pps remained the same or decreased in eight animals, increased by small but significant amounts in three rats, and increased substantially in six subjects. Unexpectedly, LH lesions did not anatomically or functionally disconnect all forebrain nuclei from the VTA. Most septal and preoptic regions contained equivalent levels of True Blue label in intact and lesioned animals. In both intact and lesioned groups, VTA stimulation increased metabolic activity in the fundus of the striatum (FS), the nucleus of the diagonal band, and the medial preoptic area. On the other hand, True Blue labeling demonstrated anatomical disconnection of the accumbens, FS, substantia innominata/magnocellular preoptic nucleus (SI/MA), and bed nucleus of the stria terminalis. [14C]DG autoradiography indicated functional disconnection of the lateral preoptic area and SI/MA. Correlations between patterns of True Blue labeling or [14C]deoxyglucose accumulation and postlesion shifts in threshold pulse frequency were weak and generally negative. These direct measures of connectivity concord with the behavioral measures in suggesting a diffuse net-like connection between forebrain nuclei and the VTA.

Mast cells in the sheep, hedgehog and rat forebrain

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MICHALOUDI, HELEN C.; PAPADOPOULOS, GEORGIOS C.

1999-01-01

The study was designed to reveal the distribution of various mast cell types in the forebrain of the adult sheep, hedgehog and rat. Based on their histochemical and immunocytochemical characteristics, mast cells were categorised as (1) connective tissue-type mast cells, staining metachromatically purple with the toluidine blue method, or pale red with the Alcian blue/safranin method, (2) mucosal-type or immature mast cells staining blue with the Alcian blue/safranin method and (3) serotonin immunopositive mast cells. All 3 types of brain mast cells in all species studied were located in both white and grey matter, often associated with intraparenchymal blood vessels. Their distribution pattern exhibited interspecies differences, while their number varied considerably not only between species but also between individuals of each species. A distributional left-right asymmetry, with more cells present on the left side, was observed in all species studied but it was most prominent in the sheep brain. In the sheep, mast cells were abundantly distributed in forebrain areas, while in the hedgehog and the rat forebrain, mast cells were less widely distributed and were relatively or substantially fewer in number respectively. A limited number of brain mast cells, in all 3 species, but primarily in the rat, were found to react both immunocytochemically to 5-HT antibody and histochemically with Alcian blue/safranin staining. PMID:10634696

Receptors for GRP/bombesin-like peptides in the rat forebrain

International Nuclear Information System (INIS)

Wolf, S.S.; Moody, T.W.

1985-01-01

Binding sites in the rat forebrain were characterized using ( 125 I-Tyr4)bombesin as a receptor probe. Pharmacology experiments indicate that gastrin releasing peptide (GRP) and the GRP fragments GRP as well as Ac-GRP inhibited radiolabeled (Tyr4)bombesin binding with high affinity. Biochemistry experiments indicated that heat, N-ethyl maleimide or trypsin greatly reduced radiolabeled (Tyr4)bombesin binding. Also, autoradiographic studies indicated that highest grain densities were present in the stria terminalis, periventricular and suprachiasmatic nucleus of the hypothalamus, dorsomedial and rhomboid thalamus, dentate gyrus, hippocampus and medial amygdaloid nucleus. The data suggest that CNS protein receptors, which are discretely distributed in the rat forebrain, may mediate the action of endogenous GRP/bombesin-like peptides

Microbial Inactivation by Ultrasound Assisted Supercritical Fluids

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Benedito, Jose; Ortuño, Carmen; Castillo-Zamudio, Rosa Isela; Mulet, Antonio

A method combining supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) has been developed and tested for microbial/enzyme inactivation purposes, at different process conditions for both liquid and solid matrices. In culture media, using only SC-CO2, the inactivation rate of E. coli and S. cerevisiae increased with pressure and temperature; and the total inactivation (7-8 log-cycles) was attained after 25 and 140 min of SC-CO2 (350 bar, 36 °C) treatment, respectively. Using SC-CO2+HPU, the time for the total inactivation of both microorganisms was reduced to only 1-2 min, at any condition selected. The SC-CO2+HPU inactivation of both microorganisms was slower in juices (avg. 4.9 min) than in culture media (avg. 1.5 min). In solid samples (chicken, turkey ham and dry-cured pork cured ham) treated with SC-CO2 and SC-CO2+HPU, the inactivation rate of E. coli increased with temperature. The application of HPU to the SC-CO2 treatments accelerated the inactivation rate of E. coli and that effect was more pronounced in treatments with isotonic solution surrounding the solid food samples. The application of HPU enhanced the SC-CO2 inactivation mechanisms of microorganisms, generating a vigorous agitation that facilitated the CO2 solubilization and the mass transfer process. The cavitation generated by HPU could damage the cell walls accelerating the extraction of vital constituents and the microbial death. Thus, using the combined technique, reasonable industrial processing times and mild process conditions could be used which could result into a cost reduction and lead to the minimization in the food nutritional and organoleptic changes.

Ablation of CaV2.1 Voltage-Gated Ca2+ Channels in Mouse Forebrain Generates Multiple Cognitive Impairments

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Mallmann, Robert Theodor; Elgueta, Claudio; Sleman, Faten; Castonguay, Jan; Wilmes, Thomas; van den Maagdenberg, Arn; Klugbauer, Norbert

2013-01-01

Voltage-gated CaV2.1 (P/Q-type) Ca2+ channels located at the presynaptic membrane are known to control a multitude of Ca2+-dependent cellular processes such as neurotransmitter release and synaptic plasticity. Our knowledge about their contributions to complex cognitive functions, however, is restricted by the limited adequacy of existing transgenic CaV2.1 mouse models. Global CaV2.1 knock-out mice lacking the α1 subunit Cacna1a gene product exhibit early postnatal lethality which makes them unsuitable to analyse the relevance of CaV2.1 Ca2+ channels for complex behaviour in adult mice. Consequently we established a forebrain specific CaV2.1 knock-out model by crossing mice with a floxed Cacna1a gene with mice expressing Cre-recombinase under the control of the NEX promoter. This novel mouse model enabled us to investigate the contribution of CaV2.1 to complex cognitive functions, particularly learning and memory. Electrophysiological analysis allowed us to test the specificity of our conditional knock-out model and revealed an impaired synaptic transmission at hippocampal glutamatergic synapses. At the behavioural level, the forebrain-specific CaV2.1 knock-out resulted in deficits in spatial learning and reference memory, reduced recognition memory, increased exploratory behaviour and a strong attenuation of circadian rhythmicity. In summary, we present a novel conditional CaV2.1 knock-out model that is most suitable for analysing the in vivo functions of CaV2.1 in the adult murine forebrain. PMID:24205277

Inactivation of VHSV by infiltration and salt under experimental conditions

DEFF Research Database (Denmark)

Skall, Helle Frank; Jørgensen, Claus; Olesen, Niels Jørgen

2014-01-01

At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by infiltration. To evaluate the inactivation effect of infiltration on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid...... be a valuable method to sanitize VHSV infected water. Changes in temperature, pH, earth types in the area used for infiltration etc. may change the virus reduction, though. As some of the fish cutting plants are also smoking rainbow trout fillets, the question arose whether a brine solution will inactivate VHSV...

TASK Channels on Basal Forebrain Cholinergic Neurons Modulate Electrocortical Signatures of Arousal by Histamine.

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Vu, Michael T; Du, Guizhi; Bayliss, Douglas A; Horner, Richard L

2015-10-07

Basal forebrain cholinergic neurons are the main source of cortical acetylcholine, and their activation by histamine elicits cortical arousal. TWIK-like acid-sensitive K(+) (TASK) channels modulate neuronal excitability and are expressed on basal forebrain cholinergic neurons, but the role of TASK channels in the histamine-basal forebrain cholinergic arousal circuit is unknown. We first expressed TASK channel subunits and histamine Type 1 receptors in HEK cells. Application of histamine in vitro inhibited the acid-sensitive K(+) current, indicating a functionally coupled signaling mechanism. We then studied the role of TASK channels in modulating electrocortical activity in vivo using freely behaving wild-type (n = 12) and ChAT-Cre:TASK(f/f) mice (n = 12), the latter lacking TASK-1/3 channels on cholinergic neurons. TASK channel deletion on cholinergic neurons significantly altered endogenous electroencephalogram oscillations in multiple frequency bands. We then identified the effect of TASK channel deletion during microperfusion of histamine into the basal forebrain. In non-rapid eye movement sleep, TASK channel deletion on cholinergic neurons significantly attenuated the histamine-induced increase in 30-50 Hz activity, consistent with TASK channels contributing to histamine action on basal forebrain cholinergic neurons. In contrast, during active wakefulness, histamine significantly increased 30-50 Hz activity in ChAT-Cre:TASK(f/f) mice but not wild-type mice, showing that the histamine response depended upon the prevailing cortical arousal state. In summary, we identify TASK channel modulation in response to histamine receptor activation in vitro, as well as a role of TASK channels on cholinergic neurons in modulating endogenous oscillations in the electroencephalogram and the electrocortical response to histamine at the basal forebrain in vivo. Attentive states and cognitive function are associated with the generation of γ EEG activity. Basal forebrain

Pre-Training Reversible Inactivation of the Basal Amygdala (BA Disrupts Contextual, but Not Auditory, Fear Conditioning, in Rats.

Directory of Open Access Journals (Sweden)

Elisa Mari Akagi Jordão

Full Text Available The basolateral amygdala complex (BLA, including the lateral (LA, basal (BA and accessory basal (AB nuclei, is involved in acquisition of contextual and auditory fear conditioning. The BA is one of the main targets for hippocampal information, a brain structure critical for contextual learning, which integrates several discrete stimuli into a single configural representation. Congruent with the hodology, selective neurotoxic damage to the BA results in impairments in contextual, but not auditory, fear conditioning, similarly to the behavioral impairments found after hippocampal damage. This study evaluated the effects of muscimol-induced reversible inactivation of the BA during a simultaneous contextual and auditory fear conditioning training on later fear responses to both the context and the tone, tested separately, without muscimol administration. As compared to control rats micro-infused with vehicle, subjects micro-infused with muscimol before training exhibited, during testing without muscimol, significant reduction of freezing responses to the conditioned context, but not to the conditioned tone. Therefore, reversible inactivation of the BA during training impaired contextual, but not auditory fear conditioning, thus confirming and extending similar behavioral observations following selective neurotoxic damage to the BA and, in addition, revealing that this effect is not related to the lack of a functional BA during testing.

Inactivation of Bacillus anthracis spores by a combination of biocides and heating under high-temperature short-time pasteurization conditions.

Science.gov (United States)

Xu, Sa; Labuza, Theodore P; Diez-Gonzalez, Francisco

2008-06-01

The milk supply is considered a primary route for a bioterrorism attack with Bacillus anthracis spores because typical high-temperature short-time (HTST) pasteurization conditions cannot inactivate spores. In the event of intentional contamination, an effective method to inactivate the spores in milk under HTST processing conditions is needed. This study was undertaken to identify combinations and concentrations of biocides that can inactivate B. anthracis spores at temperatures in the HTST range in less than 1 min. Hydrogen peroxide (HP), sodium hypochlorite (SH), and peroxyacetic acid (PA) were evaluated for their efficacy in inactivating spores of strains 7702, ANR-1, and 9131 in milk at 72, 80, and 85 degrees C using a sealed capillary tube technique. Strains ANR-1 and 9131 were more resistant to all of the biocide treatments than strain 7702. Addition of 1,260 ppm SH to milk reduced the number of viable spores of each strain by 6 log CFU/ml in less than 90 and 60 s at 72 and 80 degrees C, respectively. After neutralization, 1,260 ppm SH reduced the time necessary to inactivate 6 log CFU/ml (TTI6-log) at 80 degrees C to less than 20 s. Treatment of milk with 7,000 ppm HP resulted in a similar level of inactivation in 60 s. Combined treatment with 1,260 ppm SH and 1,800 ppm HP inactivated spores of all strains in less than 20 s at 80 degrees C. Mixing 15 ppm PA with milk containing 1,260 ppm SH resulted in TTI6-log of 25 and 12 s at 72 and 80 degrees C, respectively. TTI6-log of less than 20 s were also achieved at 80 degrees C by using two combinations of biocides: 250 ppm SH, 700 ppm HP, and 150 ppm PA; and 420 ppm SH (pH 7), 1,100 ppm HP, and 15 ppm PA. These results indicated that different combinations of biocides could consistently result in 6-log reductions in the number of B. anthracis spores in less than 1 min at temperatures in the HTST range. This information could be useful for developing more effective thermal treatment strategies which could be

Shp2 in Forebrain Neurons Regulates Synaptic Plasticity, Locomotion, and Memory Formation in Mice

Science.gov (United States)

Kusakari, Shinya; Saitow, Fumihito; Ago, Yukio; Shibasaki, Koji; Sato-Hashimoto, Miho; Matsuzaki, Yasunori; Kotani, Takenori; Murata, Yoji; Hirai, Hirokazu; Matsuda, Toshio; Suzuki, Hidenori

2015-01-01

Shp2 (Src homology 2 domain-containing protein tyrosine phosphatase 2) regulates neural cell differentiation. It is also expressed in postmitotic neurons, however, and mutations of Shp2 are associated with clinical syndromes characterized by mental retardation. Here we show that conditional-knockout (cKO) mice lacking Shp2 specifically in postmitotic forebrain neurons manifest abnormal behavior, including hyperactivity. Novelty-induced expression of immediate-early genes and activation of extracellular-signal-regulated kinase (Erk) were attenuated in the cerebral cortex and hippocampus of Shp2 cKO mice, suggestive of reduced neuronal activity. In contrast, ablation of Shp2 enhanced high-K+-induced Erk activation in both cultured cortical neurons and synaptosomes, whereas it inhibited that induced by brain-derived growth factor in cultured neurons. Posttetanic potentiation and paired-pulse facilitation were attenuated and enhanced, respectively, in hippocampal slices from Shp2 cKO mice. The mutant mice also manifested transient impairment of memory formation in the Morris water maze. Our data suggest that Shp2 contributes to regulation of Erk activation and synaptic plasticity in postmitotic forebrain neurons and thereby controls locomotor activity and memory formation. PMID:25713104

RAGE mediates the inactivation of nAChRs in sympathetic neurons under high glucose conditions.

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Chandna, Andrew R; Nair, Manoj; Chang, Christine; Pennington, Paul R; Yamamoto, Yasuhiko; Mousseau, Darrell D; Campanucci, Verónica A

2015-02-01

Autonomic dysfunction is a serious complication of diabetes and can lead to cardiovascular abnormalities and premature death. It was recently proposed that autonomic dysfunction is triggered by oxidation-mediated inactivation of neuronal nicotinic acetylcholine receptors (nAChRs), impairing synaptic transmission in sympathetic ganglia and resulting in autonomic failure. We investigated whether the receptor for advanced glycation end products (RAGE) and its role in the generation of reactive oxygen species (ROS) could be contributing to the events that initiate sympathetic malfunction under high glucose conditions. Using biochemical, live imaging and electrophysiological tools we demonstrated that exposure of sympathetic neurons to high glucose increases RAGE expression and oxidative markers, and that incubation with RAGE ligands (e.g. AGEs, S100 and HMGB1) mimics both ROS elevation and nAChR inactivation. In contrast, co-treatment with either antioxidants or an anti-RAGE IgG prevented the inactivation of nAChRs. Lastly, a role for RAGE in this context was corroborated by the lack of sensitivity of sympathetic neurons from RAGE knock-out mice to high glucose. These data define a pivotal role for RAGE in initiating the events associated with exposure of sympathetic neurons to high glucose, and strongly support RAGE signaling as a potential therapeutic target in the autonomic complications associated with diabetes. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Prosomeric map of the lamprey forebrain based on calretinin immunocytochemistry, Nissl stain, and ancillary markers.

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Pombal, M A; Puelles, L

1999-11-22

The structural organization of the lamprey extratelencephalic forebrain is re-examined from the perspective of the prosomeric segmental paradigm. The question asked was whether the prosomeric forebrain model used for gnathostomes is of material advantage for interpreting subdivisions in the lamprey forebrain. To this aim, the main longitudinal and transverse landmarks recognized by the prosomeric model in other vertebrates were identified in Nissl-stained lamprey material. Lines of cytoarchitectural discontinuity and contours of migrated neuronal groups were mapped in a two-dimensional sagittal representation and were also classified according to their radial position. Immunocytochemical mapping of calretinin expression in adjacent sections served to define particular structural units better, in particular, the dorsal thalamus. These data were complemented by numerous other chemoarchitectonic observations obtained with ancillary markers, which identified additional specific formations, subdivisions, or boundaries. Emphasis was placed on studying whether such chemically defined neuronal groups showed boundaries aligned with the postulated inter- or intraprosomeric boundaries. The course of diverse axonal tracts was studied also with regard to their prosomeric topography. This analysis showed that the full prosomeric model applies straightforwardly to the lamprey forebrain. This finding implies that a common segmental and longitudinal organization of the neural tube may be primitive for all vertebrates. Interesting novel aspects appear in the interpretation of the lamprey pretectum, the dorsal and ventral thalami, and the hypothalamus. The topologic continuity of the prosomeric forebrain regions with evaginated or non-evaginated portions of the telencephalon was also examined. Copyright 1999 Wiley-Liss, Inc.

Inactivation of enteropathogenic E. coli by solar disinfection (SODIS) under simulated sunlight conditions

CSIR Research Space (South Africa)

Ubomba-Jaswa, Eunice

2008-12-01

Full Text Available of limitations. An important limitation is the lack of SODIS inactivation studies on some waterborne pathogens in the developing world. SODIS inactivation of enteropathogenic E. coli (EPEC), a major cause of infantile diarrhoea is reported for the first time...

Ablation of Ca(V)2.1 voltage-gated Ca²⁺ channels in mouse forebrain generates multiple cognitive impairments.

Science.gov (United States)

Mallmann, Robert Theodor; Elgueta, Claudio; Sleman, Faten; Castonguay, Jan; Wilmes, Thomas; van den Maagdenberg, Arn; Klugbauer, Norbert

2013-01-01

Voltage-gated Ca(V)2.1 (P/Q-type) Ca²⁺ channels located at the presynaptic membrane are known to control a multitude of Ca²⁺-dependent cellular processes such as neurotransmitter release and synaptic plasticity. Our knowledge about their contributions to complex cognitive functions, however, is restricted by the limited adequacy of existing transgenic Ca(V)2.1 mouse models. Global Ca(V)2.1 knock-out mice lacking the α1 subunit Cacna1a gene product exhibit early postnatal lethality which makes them unsuitable to analyse the relevance of Ca(V)2.1 Ca²⁺ channels for complex behaviour in adult mice. Consequently we established a forebrain specific Ca(V)2.1 knock-out model by crossing mice with a floxed Cacna1a gene with mice expressing Cre-recombinase under the control of the NEX promoter. This novel mouse model enabled us to investigate the contribution of Ca(V)2.1 to complex cognitive functions, particularly learning and memory. Electrophysiological analysis allowed us to test the specificity of our conditional knock-out model and revealed an impaired synaptic transmission at hippocampal glutamatergic synapses. At the behavioural level, the forebrain-specific Ca(V)2.1 knock-out resulted in deficits in spatial learning and reference memory, reduced recognition memory, increased exploratory behaviour and a strong attenuation of circadian rhythmicity. In summary, we present a novel conditional Ca(V)2.1 knock-out model that is most suitable for analysing the in vivo functions of Ca(V)2.1 in the adult murine forebrain.

Modulation of learning and memory by the targeted deletion of the circadian clock gene Bmal1 in forebrain circuits.

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Snider, Kaitlin H; Dziema, Heather; Aten, Sydney; Loeser, Jacob; Norona, Frances E; Hoyt, Kari; Obrietan, Karl

2016-07-15

A large body of literature has shown that the disruption of circadian clock timing has profound effects on mood, memory and complex thinking. Central to this time keeping process is the master circadian pacemaker located within the suprachiasmatic nucleus (SCN). Of note, within the central nervous system, clock timing is not exclusive to the SCN, but rather, ancillary oscillatory capacity has been detected in a wide range of cell types and brain regions, including forebrain circuits that underlie complex cognitive processes. These observations raise questions about the hierarchical and functional relationship between the SCN and forebrain oscillators, and, relatedly, about the underlying clock-gated synaptic circuitry that modulates cognition. Here, we utilized a clock knockout strategy in which the essential circadian timing gene Bmal1 was selectively deleted from excitatory forebrain neurons, whilst the SCN clock remained intact, to test the role of forebrain clock timing in learning, memory, anxiety, and behavioral despair. With this model system, we observed numerous effects on hippocampus-dependent measures of cognition. Mice lacking forebrain Bmal1 exhibited deficits in both acquisition and recall on the Barnes maze. Notably, loss of forebrain Bmal1 abrogated time-of-day dependent novel object location memory. However, the loss of Bmal1 did not alter performance on the elevated plus maze, open field assay, and tail suspension test, indicating that this phenotype specifically impairs cognition but not affect. Together, these data suggest that forebrain clock timing plays a critical role in shaping the efficiency of learning and memory retrieval over the circadian day. Copyright © 2016 Elsevier B.V. All rights reserved.

Decreased levels of free D-aspartic acid in the forebrain of serine racemase (Srr) knock-out mice.

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Horio, Mao; Ishima, Tamaki; Fujita, Yuko; Inoue, Ran; Mori, Hisashi; Hashimoto, Kenji

2013-05-01

d-Serine, an endogenous co-agonist of the N-methyl-d-aspartate (NMDA) receptor is synthesized from l-serine by serine racemase (SRR). A previous study of Srr knockout (Srr-KO) mice showed that levels of d-serine in forebrain regions, such as frontal cortex, hippocampus, and striatum, but not cerebellum, of mutant mice are significantly lower than those of wild-type (WT) mice, suggesting that SRR is responsible for d-serine production in the forebrain. In this study, we attempted to determine whether SRR affects the level of other amino acids in brain tissue. We found that tissue levels of d-aspartic acid in the forebrains (frontal cortex, hippocampus and striatum) of Srr-KO mice were significantly lower than in WT mice, whereas levels of d-aspartic acid in the cerebellum were not altered. Levels of d-alanine, l-alanine, l-aspartic acid, taurine, asparagine, arginine, threonine, γ-amino butyric acid (GABA) and methionine, remained the same in frontal cortex, hippocampus, striatum and cerebellum of WT and mutant mice. Furthermore, no differences in d-aspartate oxidase (DDO) activity were detected in the forebrains of WT and Srr-KO mice. These results suggest that SRR and/or d-serine may be involved in the production of d-aspartic acid in mouse forebrains, although further detailed studies will be necessary to confirm this finding. Copyright © 2013 Elsevier Ltd. All rights reserved.

Conditional inactivation of Brca1 in the mouse ovarian surface epithelium results in an increase in preneoplastic changes

International Nuclear Information System (INIS)

Clark-Knowles, Katherine V.; Garson, Kenneth; Jonkers, Jos; Vanderhyden, Barbara C.

2007-01-01

Epithelial ovarian cancer (EOC) is thought to arise from the ovarian surface epithelium (OSE); however, the molecular events underlying this transformation are poorly understood. Germline mutations in the BRCA1 tumor suppressor gene result in a significantly increased risk of developing EOC and a large proportion of sporadic EOCs display some sort of BRCA1 dysfunction. Using mice with conditional expression of Brca1, we inactivated Brca1 in the murine OSE and demonstrate that this inactivation results in the development of preneoplastic changes, such as hyperplasia, epithelial invaginations, and inclusion cysts, which arise earlier and are more numerous than in control ovaries. These changes resemble the premalignant lesions that have been reported in human prophylactic oophorectomy specimens from women with BRCA1 germline mutation. We also report that inactivation of Brca1 in primary cultures of murine OSE cells leads to a suppression of proliferation due to increased apoptosis that can be rescued by concomitant inactivation of p53. These observations, along with our finding that these cells display an increased sensitivity to the DNA-damaging agent cisplatin, indicate that loss of function of Brca1 in OSE cells impacts both cellular growth control and DNA-damage repair which results in altered cell behavior manifested as morphological changes in vivo that arise earlier and are more numerous than what can be attributed to ageing

Inactivation of Bacillus anthracis Spores by a Combination of Biocides and Heating under High-Temperature Short-Time Pasteurization Conditions ▿

Science.gov (United States)

Xu, Sa; Labuza, Theodore P.; Diez-Gonzalez, Francisco

2008-01-01

The milk supply is considered a primary route for a bioterrorism attack with Bacillus anthracis spores because typical high-temperature short-time (HTST) pasteurization conditions cannot inactivate spores. In the event of intentional contamination, an effective method to inactivate the spores in milk under HTST processing conditions is needed. This study was undertaken to identify combinations and concentrations of biocides that can inactivate B. anthracis spores at temperatures in the HTST range in less than 1 min. Hydrogen peroxide (HP), sodium hypochlorite (SH), and peroxyacetic acid (PA) were evaluated for their efficacy in inactivating spores of strains 7702, ANR-1, and 9131 in milk at 72, 80, and 85°C using a sealed capillary tube technique. Strains ANR-1 and 9131 were more resistant to all of the biocide treatments than strain 7702. Addition of 1,260 ppm SH to milk reduced the number of viable spores of each strain by 6 log CFU/ml in less than 90 and 60 s at 72 and 80°C, respectively. After neutralization, 1,260 ppm SH reduced the time necessary to inactivate 6 log CFU/ml (TTI6-log) at 80°C to less than 20 s. Treatment of milk with 7,000 ppm HP resulted in a similar level of inactivation in 60 s. Combined treatment with 1,260 ppm SH and 1,800 ppm HP inactivated spores of all strains in less than 20 s at 80°C. Mixing 15 ppm PA with milk containing 1,260 ppm SH resulted in TTI6-log of 25 and 12 s at 72 and 80°C, respectively. TTI6-log of less than 20 s were also achieved at 80°C by using two combinations of biocides: 250 ppm SH, 700 ppm HP, and 150 ppm PA; and 420 ppm SH (pH 7), 1,100 ppm HP, and 15 ppm PA. These results indicated that different combinations of biocides could consistently result in 6-log reductions in the number of B. anthracis spores in less than 1 min at temperatures in the HTST range. This information could be useful for developing more effective thermal treatment strategies which could be used in HTST milk plants to process

Optogenetic fMRI and electrophysiological identification of region-specific connectivity between the cerebellar cortex and forebrain.

Science.gov (United States)

Choe, Katrina Y; Sanchez, Carlos F; Harris, Neil G; Otis, Thomas S; Mathews, Paul J

2018-06-01

Complex animal behavior is produced by dynamic interactions between discrete regions of the brain. As such, defining functional connections between brain regions is critical in gaining a full understanding of how the brain generates behavior. Evidence suggests that discrete regions of the cerebellar cortex functionally project to the forebrain, mediating long-range communication potentially important in motor and non-motor behaviors. However, the connectivity map remains largely incomplete owing to the challenge of driving both reliable and selective output from the cerebellar cortex, as well as the need for methods to detect region specific activation across the entire forebrain. Here we utilize a paired optogenetic and fMRI (ofMRI) approach to elucidate the downstream forebrain regions modulated by activating a region of the cerebellum that induces stereotypical, ipsilateral forelimb movements. We demonstrate with ofMRI, that activating this forelimb motor region of the cerebellar cortex results in functional activation of a variety of forebrain and midbrain areas of the brain, including the hippocampus and primary motor, retrosplenial and anterior cingulate cortices. We further validate these findings using optogenetic stimulation paired with multi-electrode array recordings and post-hoc staining for molecular markers of activated neurons (i.e. c-Fos). Together, these findings demonstrate that a single discrete region of the cerebellar cortex is capable of influencing motor output and the activity of a number of downstream forebrain as well as midbrain regions thought to be involved in different aspects of behavior. Copyright © 2018 Elsevier Inc. All rights reserved.

Genetic activation, inactivation and deletion reveal a limited and nuanced role for somatostatin-containing basal forebrain neurons in behavioral state control.

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Anaclet, Christelle; De Luca, Roberto; Venner, Anne; Malyshevskaya, Olga; Lazarus, Michael; Arrigoni, Elda; Fuller, Patrick M

2018-05-07

Recent studies have identified an especially important role for basal forebrain GABAergic (BF VGAT ) neurons in the regulation of behavioral waking and fast cortical rhythms associated with cognition. However, BF VGAT neurons comprise several neurochemically and anatomically distinct sub-populations, including parvalbumin- and somatostatin-containing BF VGAT neurons (BF Parv and BF SOM ), and it was recently reported that optogenetic activation of BF SOM neurons increases the probability of a wakefulness to non-rapid-eye movement (NREM) sleep transition when stimulated during the animal's rest period. This finding was unexpected given that most BF SOM neurons are not NREM sleep active and that central administration of the synthetic SOM analog, octreotide, suppresses NREM sleep or increases REM sleep. Here we employed a combination of genetically-driven chemogenetic and optogenetic activation, chemogenetic inhibition and ablation approaches to further explore the in vivo role of BF SOM neurons in arousal control. Our findings indicate that acute activation or inhibition of BF SOM neurons is neither wakefulness- nor NREM sleep-promoting, is without significant effect on the EEG, and that chronic loss of these neurons is without effect on total 24h sleep amounts, although a small but significant increase in waking was observed in the lesioned mice during the early active period. Our in vitro cell recordings further reveal electrophysiological heterogeneity in BF SOM neurons, specifically suggesting at least two distinct sub-populations. Taken together our data support the more nuanced view that BF SOM are electrically heterogeneous and are not NREM sleep- or wake-promoting per se , but may exert, in particular during the early active period, a modest inhibitory influence on arousal circuitry. SIGNIFICANCE STATEMENT The cellular basal forebrain (BF) is a highly complex area of the brain that is implicated in a wide-range of higher-level neurobiological processes

Directed differentiation of basal forebrain cholinergic neurons from human pluripotent stem cells.

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Hu, Yao; Qu, Zhuang-Yin; Cao, Shi-Ying; Li, Qi; Ma, Lixiang; Krencik, Robert; Xu, Min; Liu, Yan

2016-06-15

Basal forebrain cholinergic neurons (BFCNs) play critical roles in learning, memory and cognition. Dysfunction or degeneration of BFCNs may connect to neuropathology, such as Alzheimer's disease, Down's syndrome and dementia. Generation of functional BFCNs may contribute to the studies of cell-based therapy and pathogenesis that is related to learning and memory deficits. Here we describe a detail method for robust generation of BFCNs from human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs). In this method, BFCN progenitors are patterned from hESC or hiPSC-derived primitive neuroepithelial cells, with the treatment of sonic hedgehog (SHH) or combination with its agonist Purmorphamine, and by co-culturing with human astrocytes. At day 20, ∼90% hPSC-derived progenitors expressed NKX2.1, which is a transcriptional marker for MGE. Moreover, around 40% of NKX2.1+ cells co-expressed OLIG2 and ∼15% of NKX2.1+ cells co-expressed ISLET1, which are ventral markers. At day 35, ∼40% neurons robustly express ChAT, most of which are co-labeled with NKX2.1, ISLET1 and FOXG1, indicating the basal forebrain-like identity. At day 45, these neurons express mature neuronal markers MAP2, Synapsin, and VAChT. In this method, undefined conditions including genetic modification or cell-sorting are avoided. As a choice, feeder free conditions are used to avoid ingredients of animal origin. Moreover, Purmorphamine can be substituted for SHH to induce ventral progenitors effectively and economically. We provide an efficient method to generate BFCNs from multiple hPSC lines, which offers the potential application for disease modeling and pharmacological studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Ablation of Ca(V2.1 voltage-gated Ca²⁺ channels in mouse forebrain generates multiple cognitive impairments.

Directory of Open Access Journals (Sweden)

Robert Theodor Mallmann

Full Text Available Voltage-gated Ca(V2.1 (P/Q-type Ca²⁺ channels located at the presynaptic membrane are known to control a multitude of Ca²⁺-dependent cellular processes such as neurotransmitter release and synaptic plasticity. Our knowledge about their contributions to complex cognitive functions, however, is restricted by the limited adequacy of existing transgenic Ca(V2.1 mouse models. Global Ca(V2.1 knock-out mice lacking the α1 subunit Cacna1a gene product exhibit early postnatal lethality which makes them unsuitable to analyse the relevance of Ca(V2.1 Ca²⁺ channels for complex behaviour in adult mice. Consequently we established a forebrain specific Ca(V2.1 knock-out model by crossing mice with a floxed Cacna1a gene with mice expressing Cre-recombinase under the control of the NEX promoter. This novel mouse model enabled us to investigate the contribution of Ca(V2.1 to complex cognitive functions, particularly learning and memory. Electrophysiological analysis allowed us to test the specificity of our conditional knock-out model and revealed an impaired synaptic transmission at hippocampal glutamatergic synapses. At the behavioural level, the forebrain-specific Ca(V2.1 knock-out resulted in deficits in spatial learning and reference memory, reduced recognition memory, increased exploratory behaviour and a strong attenuation of circadian rhythmicity. In summary, we present a novel conditional Ca(V2.1 knock-out model that is most suitable for analysing the in vivo functions of Ca(V2.1 in the adult murine forebrain.

Morphometric Studies Of The Cerebellum And Forebrain Of The ...

African Journals Online (AJOL)

Morphometric studies were undertaken using the brains of six African giant rats. The mean of weights and lengths (tip of the olfactory bulb to the caudal border of the cerebellum) were observed tobe 4.88 0.183g and 4.40 0.193g, respectively. Similarly, the mean weight and length of the cerebellum and the forebrain ...

Effects of pre- or post-processing storage conditions on high-hydrostatic pressure inactivation of Vibrio parahaemolyticus and V. vulnificus in oysters.

Science.gov (United States)

Ye, Mu; Huang, Yaoxin; Gurtler, Joshua B; Niemira, Brendan A; Sites, Joseph E; Chen, Haiqiang

2013-05-15

The effects of storage conditions on subsequent high-hydrostatic pressure (HHP) inactivation of Vibrio parahaemolyticus and Vibrio vulnificus in oysters were investigated. Live oysters were inoculated with V. parahaemolyticus or V. vulnificus to ca. 7-8 log MPN/g by feeding and stored at varying conditions (i.e., 21 or 35 °C for 5h, 4 or 10 °C for 1 and 2 days and -18 °C for 2 weeks). Oyster meats were then treated at 225-300 MPa for 2 min at 4, 21 or 35 °C. HHP at 300 MPa for 2 min achieved a >5-log MPN/g reduction of V. parahaemolyticus, completely inactivating V. vulnificus (negative by enrichment) in oysters. Treatment temperatures of 4, 21 and 35 °C did not significantly affect pressure inactivation of V. parahaemolyticus or V. vulnificus (P>0.05). Cold storage at -18, 4 and 10 °C, prior to HHP, decreased V. parahaemolyticus or V. vulnificus populations by 1.5-3.0 log MPN/g, but did not increase their sensitivity to subsequent HHP treatments. The effects of cold storage after HHP on inactivation of V. parahaemolyticus in oysters were also determined. Oysters were inoculated with V. parahaemolyticus and stored at 21 °C for 5h or 4 °C for 1 day. Oyster meats were then treated at 250-300 MPa for 2 min at 21 or 35 °C and stored for 15 days in ice or in a freezer. V. parahaemolyticus populations in HHP-treated oysters gradually decreased during post-HHP ice or frozen storage. A validation study using whole-shell oysters was conducted to determine whether the presence of oyster shells influenced HHP inactivation of V. parahaemolyticus. No appreciable differences in inactivation between shucked oyster meat and whole-shell oysters were observed. HPP at 300 MPa for 2 min at 21 °C, followed by 5-day ice storage or 7-day frozen storage, and HPP at 250 MPa for 2 min at 21 °C, followed by 10-day ice or 7-day frozen storage, completely inactivated V. parahaemolyticus in whole-shell oysters (>7 log reductions). The combination of HHP at a relatively low pressure

Modeling Bacteriocin Resistance and Inactivation of Listeria innocua LMG 13568 by Lactobacillus sakei CTC 494 under Sausage Fermentation Conditions

Science.gov (United States)

Leroy, Frédéric; Lievens, Kristoff; De Vuyst, Luc

2005-01-01

In mixed cultures, bacteriocin production by the sausage isolate Lactobacillus sakei CTC 494 rapidly inactivated sensitive Listeria innocua LMG 13568 cells, even at low bacteriocin activity levels. A small fraction of the listerial population was bacteriocin resistant. However, sausage fermentation conditions inhibited regrowth of resistant cells. PMID:16269805

Physical inactivation and stabilization of sludges

International Nuclear Information System (INIS)

Alexandre, D.

1979-07-01

High temperature conditioning of sludge is a stabilization process that insures sterilization. Both thermal pasteurization and irradiation are inactivation processes. Viruses and parasites are inactivated at 70-80 0 C. Total bacterial destruction requires higher temperatures and/or detention time. Radio sensitivity of pathogens and pertinent treatment parameters are examined. If sludge is to be land disposed, disinfection requires irradiation doses ranging 500 Krad; if cattle feeding is considered, the required dose is 1 Mrad

Thyroid hormone modulates the development of cholinergic terminal fields in the rat forebrain: relation to nerve growth factor receptor.

Science.gov (United States)

Oh, J D; Butcher, L L; Woolf, N J

1991-04-24

terminals in the ventrobasal thalamus, which derive from ChAT-positive neurons in the pedunculopontine and laterodorsal tegmental nucleus, were unaffected by either hyperthyroid or hypothyroid conditions. These cells also do not demonstrate NGF-R. We conclude from these experiments (1) that cholinergic fiber plexuses eventually exhibiting ChAT positivity in the telencephalon demonstrate NGF-R prior to the cholinergic synthetic enzyme, (2) that susceptibility to thyroid hormone manipulations may involve sensitivity to NGF, at least in some forebrain cholinergic systems and (3) that the effects of thyroid hormone imbalances on brain cholinergic neurons are regionally selective.

Serotonin 5-HT4 receptors and forebrain cholinergic system: receptor expression in identified cell populations.

Science.gov (United States)

Peñas-Cazorla, Raúl; Vilaró, M Teresa

2015-11-01

Activation of serotonin 5-HT4 receptors has pro-cognitive effects on memory performance. The proposed underlying neurochemical mechanism is the enhancement of acetylcholine release in frontal cortex and hippocampus elicited by 5-HT4 agonists. Although 5-HT4 receptors are present in brain areas related to cognition, e.g., hippocampus and cortex, the cellular localization of the receptors that might modulate acetylcholine release is unknown at present. We have analyzed, using dual label in situ hybridization, the cellular localization of 5-HT4 receptor mRNA in identified neuronal populations of the rat basal forebrain, which is the source of the cholinergic innervation to cortex and hippocampus. 5-HT4 receptor mRNA was visualized with isotopically labeled oligonucleotide probes, whereas cholinergic, glutamatergic, GABAergic and parvalbumin-synthesizing neurons were identified with digoxigenin-labeled oligonucleotide probes. 5-HT4 receptor mRNA was not detected in the basal forebrain cholinergic cell population. In contrast, basal forebrain GABAergic, parvalbumin synthesizing, and glutamatergic cells contained 5-HT4 receptor mRNA. Hippocampal and cortical glutamatergic neurons also express this receptor. These results indicate that 5-HT4 receptors are not synthesized by cholinergic cells, and thus would be absent from cholinergic terminals. In contrast, several non-cholinergic cell populations within the basal forebrain and its target hippocampal and cortical areas express these receptors and are thus likely to mediate the enhancement of acetylcholine release elicited by 5-HT4 agonists.

Ontogenetic distribution of the transcription factor Nkx2.2 in the developing forebrain of Xenopus laevis

Directory of Open Access Journals (Sweden)

Laura eDominguez

2011-03-01

Full Text Available The expression of the Nkx2.2 gene is involved in the organization of the alar-basal boundary in the forebrain of vertebrates. Its expression in different diencephalic and telencephalic regions, helped to define distinct progenitor domains in mouse and chick. Here we investigated the pattern of Nkx2.2 protein distribution throughout the development of the forebrain of the anuran amphibian, Xenopus laevis. We used immunohistochemical and in situ hybridization techniques for its detection in combination with other essential territorial markers in the forebrain. No expression was observed in the telencephalon. In the alar hypothalamus, Nkx2.2 positive cells were scattered in the suprachiasmatic territory, but also in the supraoptoparaventricular area, as defined by the expression of the transcription factor Otp and the lack of xDll4. In the basal hypothalamus Nkx2.2 expressing cells were localized in the tuberal region, with the exception of the arcuate nucleus, rich in Otp expressing cells. In the diencephalon it was expressed in all three prosomeres (P1-P3 and not in the zona limitans intrathalamica. The presence of Nkx2.2 expressing cells in P3 was restricted to the alar portion, as well as in prosomere P2, whereas in P1 the Nkx2.2 expressing cells were located in the basal plate and identified the alar/basal boundary. These results showed that Nkx2.2 and Sonic hedgehog are expressed in parallel adjacent stripes along the anterior-posterior axis. The results of this study showed a conserved distribution pattern of Nkx2.2 among vertebrates, crucial to recognize subdivisions that are otherwise indistinct, and supported the relevance of this transcription factor in the organization of the forebrain, particularly in the delineation of the alar/basal boundary of the forebrain.

Effects of storage conditions before or after high-hydrostatic pressure on inactivation of Vibrio parahaemolyticus and Vibrio vulnificus in oysters

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The effect of storage conditions on subsequent high-hydrostatic pressure (HHP) inactivation of V. parahaemolyticus and V. vulnificus in oyster meat was investigated. Live oysters were inoculated with V. parahaemolyticus or V. vulnificus to ca. 7-8 log MPN/g by feeding and stored at different conditi...

Inactivation of Caliciviruses

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Raymond Nims

2013-03-01

Full Text Available The Caliciviridae family of viruses contains clinically important human and animal pathogens, as well as vesivirus 2117, a known contaminant of biopharmaceutical manufacturing processes employing Chinese hamster cells. An extensive literature exists for inactivation of various animal caliciviruses, especially feline calicivirus and murine norovirus. The caliciviruses are susceptible to wet heat inactivation at temperatures in excess of 60 °C with contact times of 30 min or greater, to UV-C inactivation at fluence ≥30 mJ/cm2, to high pressure processing >200 MPa for >5 min at 4 °C, and to certain photodynamic inactivation approaches. The enteric caliciviruses (e.g.; noroviruses display resistance to inactivation by low pH, while the non-enteric species (e.g.; feline calicivirus are much more susceptible. The caliciviruses are inactivated by a variety of chemicals, including alcohols, oxidizing agents, aldehydes, and β-propiolactone. As with inactivation of viruses in general, inactivation of caliciviruses by the various approaches may be matrix-, temperature-, and/or contact time-dependent. The susceptibilities of the caliciviruses to the various physical and chemical inactivation approaches are generally similar to those displayed by other small, non-enveloped viruses, with the exception that the parvoviruses and circoviruses may require higher temperatures for inactivation, while these families appear to be more susceptible to UV-C inactivation than are the caliciviruses.

Cortical cholinergic hypofunction and behaviorial impairment produced by basal forebrain lesions in the rat

International Nuclear Information System (INIS)

Lerer, B.E.; Friedman, E.; Gamzu, E.

1986-01-01

The authors confirm the cortical ChAT and passive avoidance deficits resulting from bilateral KA lesions of the magnocellular nuclei of the basal forebrain (MNBF). Because of reported passive avoidance deficits, the authors were interested in whether bilateral MNBF lesions would interfere with learning in an active avoidance paradigm. Samples of rat cortex were stored at -80 C until assayed. ChAT was assayed by a modification method under saturating conditions; 20 mM choline and 2 mM C 14-acetylcoenzyme. The behavioral deficits assumed to be indicative of learning and memory problems were accompanied by a 20% decrease in cortical ChAT

Basal Forebrain Cholinergic Deficits Reduce Glucose Metabolism and Function of Cholinergic and GABAergic Systems in the Cingulate Cortex.

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Jeong, Da Un; Oh, Jin Hwan; Lee, Ji Eun; Lee, Jihyeon; Cho, Zang Hee; Chang, Jin Woo; Chang, Won Seok

2016-01-01

Reduced brain glucose metabolism and basal forebrain cholinergic neuron degeneration are common features of Alzheimer's disease and have been correlated with memory function. Although regions representing glucose hypometabolism in patients with Alzheimer's disease are targets of cholinergic basal forebrain neurons, the interaction between cholinergic denervation and glucose hypometabolism is still unclear. The aim of the present study was to evaluate glucose metabolism changes caused by cholinergic deficits. We lesioned basal forebrain cholinergic neurons in rats using 192 immunoglobulin G-saporin. After 3 weeks, lesioned animals underwent water maze testing or were analyzed by ¹⁸F-2-fluoro-2-deoxyglucose positron emission tomography. During water maze probe testing, performance of the lesioned group decreased with respect to time spent in the target quadrant and platform zone. Cingulate cortex glucose metabolism in the lesioned group decreased, compared with the normal group. Additionally, acetylcholinesterase activity and glutamate decarboxylase 65/67 expression declined in the cingulate cortex. Our results reveal that spatial memory impairment in animals with selective basal forebrain cholinergic neuron damage is associated with a functional decline in the GABAergic and cholinergic system associated with cingulate cortex glucose hypometabolism.

Inactivation of VHSV by Percolation and Salt Under Experimental Conditions

DEFF Research Database (Denmark)

Skall, Helle Frank; Olesen, Niels Jørgen; Jørgensen, Claus

2012-01-01

At the moment the only legal method in Denmark to sanitize wastewater from fish cutting plants is by percolation. To evaluate the inactivation effect of percolation on VHSV an experimental examination was initiated. A column packed with gravel as top- and bottom layer (total of 22 cm) and a mid l...

Effect of basal forebrain stimulation on extracellular acetylcholine release and blood flow in the olfactory bulb.

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Uchida, Sae; Kagitani, Fusako

2017-05-12

The olfactory bulb receives cholinergic basal forebrain input, as does the neocortex; however, the in vivo physiological functions regarding the release of extracellular acetylcholine and regulation of regional blood flow in the olfactory bulb are unclear. We used in vivo microdialysis to measure the extracellular acetylcholine levels in the olfactory bulb of urethane-anesthetized rats. Focal chemical stimulation by microinjection of L-glutamate into the horizontal limb of the diagonal band of Broca (HDB) in the basal forebrain, which is the main source of cholinergic input to the olfactory bulb, increased extracellular acetylcholine release in the ipsilateral olfactory bulb. When the regional cerebral blood flow was measured using laser speckle contrast imaging, the focal chemical stimulation of the HDB did not significantly alter the blood flow in the olfactory bulb, while increases were observed in the neocortex. Our results suggest a functional difference between the olfactory bulb and neocortex regarding cerebral blood flow regulation through the release of acetylcholine by cholinergic basal forebrain input.

Widespread expression of BDNF but not NT3 by target areas of basal forebrain cholinergic neurons

Energy Technology Data Exchange (ETDEWEB)

Phillips, H.S.; Hains, J.M.; Laramee, G.R.; Rosenthal, A.; Winslow, J.W. (Genentech, San Francisco, CA (USA))

1990-10-12

Brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) are homologs of the well-known neurotrophic factor nerve growth factor. The three members of this family display distinct patterns of target specificity. To examine the distribution in brain of messenger RNA for these molecules, in situ hybridization was performed. Cells hybridizing intensely to antisense BDNF probe were located throughout the major targets of the rat basal forebrain cholinergic system, that is, the hippocampus, amygdala, and neocortex. Strongly hybridizing cells were also observed in structures associated with the olfactory system. The distribution of NT3 mRNA in forebrain was much more limited. Within the hippocampus, labeled cells were restricted to CA2, the most medial portion of CA1, and the dentate gyrus. In human hippocampus, cells expressing BDNF and mRNA are distributed in a fashion similar to that observed in the rat. These findings point to both basal forebrain cholinergic cells and olfactory pathways as potential central targets for BDNF.

Widespread expression of BDNF but not NT3 by target areas of basal forebrain cholinergic neurons

International Nuclear Information System (INIS)

Phillips, H.S.; Hains, J.M.; Laramee, G.R.; Rosenthal, A.; Winslow, J.W.

1990-01-01

Brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) are homologs of the well-known neurotrophic factor nerve growth factor. The three members of this family display distinct patterns of target specificity. To examine the distribution in brain of messenger RNA for these molecules, in situ hybridization was performed. Cells hybridizing intensely to antisense BDNF probe were located throughout the major targets of the rat basal forebrain cholinergic system, that is, the hippocampus, amygdala, and neocortex. Strongly hybridizing cells were also observed in structures associated with the olfactory system. The distribution of NT3 mRNA in forebrain was much more limited. Within the hippocampus, labeled cells were restricted to CA2, the most medial portion of CA1, and the dentate gyrus. In human hippocampus, cells expressing BDNF and mRNA are distributed in a fashion similar to that observed in the rat. These findings point to both basal forebrain cholinergic cells and olfactory pathways as potential central targets for BDNF

Agmatine protection against chlorpromazine-induced forebrain cortex injury in rats.

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Dejanovic, Bratislav; Stevanovic, Ivana; Ninkovic, Milica; Stojanovic, Ivana; Lavrnja, Irena; Radicevic, Tatjana; Pavlovic, Milos

2016-03-01

This study was conducted to investigate whether agmatine (AGM) provides protection against oxidative stress induced by treatment with chlorpromazine (CPZ) in Wistar rats. In addition, the role of reactive oxygen species and efficiency of antioxidant protection in the brain homogenates of forebrain cortexes prepared 48 h after treatment were investigated. Chlorpromazine was applied intraperitoneally (i.p.) in single dose of 38.7 mg/kg body weight (BW) The second group was treated with both CPZ and AGM (75 mg/kg BW). The control group was treated with 0.9% saline solution in the same manner. All tested compounds were administered i.p. in a single dose. Rats were sacrificed by decapitation 48 h after treatment Treatment with AGM significantly attenuated the oxidative stress parameters and restored antioxidant capacity in the forebrain cortex. The data indicated that i.p. administered AGM exerted antioxidant action in CPZ-treated animals. Moreover, reactive astrocytes and microglia may contribute to secondary nerve-cell damage and participate in the balance of destructive vs. protective actions involved in the pathogenesis after poisoning.

Basal Forebrain Cholinergic Deficits Reduce Glucose Metabolism and Function of Cholinergic and GABAergic Systems in the Cingulate Cortex

OpenAIRE

Jeong, Da Un; Oh, Jin Hwan; Lee, Ji Eun; Lee, Jihyeon; Cho, Zang Hee; Chang, Jin Woo; Chang, Won Seok

2015-01-01

Purpose Reduced brain glucose metabolism and basal forebrain cholinergic neuron degeneration are common features of Alzheimer's disease and have been correlated with memory function. Although regions representing glucose hypometabolism in patients with Alzheimer's disease are targets of cholinergic basal forebrain neurons, the interaction between cholinergic denervation and glucose hypometabolism is still unclear. The aim of the present study was to evaluate glucose metabolism changes caused ...

Hierarchical prediction errors in midbrain and basal forebrain during sensory learning.

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Iglesias, Sandra; Mathys, Christoph; Brodersen, Kay H; Kasper, Lars; Piccirelli, Marco; den Ouden, Hanneke E M; Stephan, Klaas E

2013-10-16

In Bayesian brain theories, hierarchically related prediction errors (PEs) play a central role for predicting sensory inputs and inferring their underlying causes, e.g., the probabilistic structure of the environment and its volatility. Notably, PEs at different hierarchical levels may be encoded by different neuromodulatory transmitters. Here, we tested this possibility in computational fMRI studies of audio-visual learning. Using a hierarchical Bayesian model, we found that low-level PEs about visual stimulus outcome were reflected by widespread activity in visual and supramodal areas but also in the midbrain. In contrast, high-level PEs about stimulus probabilities were encoded by the basal forebrain. These findings were replicated in two groups of healthy volunteers. While our fMRI measures do not reveal the exact neuron types activated in midbrain and basal forebrain, they suggest a dichotomy between neuromodulatory systems, linking dopamine to low-level PEs about stimulus outcome and acetylcholine to more abstract PEs about stimulus probabilities. Copyright © 2013 Elsevier Inc. All rights reserved.

Unilateral inactivation of the basolateral amygdala attenuates context-induced renewal of Pavlovian-conditioned alcohol-seeking

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Chaudhri, N.; Woods, C. A.; Sahuque, L.L.; Gill, T. M.; Janak, P.H.

2014-01-01

Environmental contexts associated with drug use promote craving in humans and drug-seeking in animals. We hypothesized that the basolateral amygdala (BLA) itself, as well as serial connectivity between the basolateral amygdala (BLA) and nucleus accumbens core (NAC core), were required for context-induced renewal of Pavlovian-conditioned alcohol-seeking. Male, Long-Evans rats were trained to discriminate between two conditioned stimuli (CS) - a CS+ that was paired with ethanol (EtOH, 20%, v/v) delivery into a fluid port (0.2 ml/CS+, 3.2 ml/session) and a CS− that was not. Entries into the port during each CS were measured. Next, rats received extinction in a different context where both cues were presented without EtOH. At test, responding to the CS+ and CS− without EtOH was evaluated in the prior training context. Control subjects showed a selective increase in CS+ responding relative to extinction, indicative of renewal. This effect was blocked by pre-test, bilateral inactivation of the BLA using a solution of gamma-amino-butyric-acid receptor agonists (0.1 mM muscimol and 1.0 mM baclofen; M/B; 0.3 µl/side). Renewal was also attenuated following unilateral injections of M/B into the BLA, combined with either M/B, the dopamine D1 receptor antagonist SCH 23390 (0.6 µg/side), or saline infusion in the contralateral NAC core. Hence, unilateral BLA inactivation was sufficient to disrupt renewal, highlighting a critical role for functional activity in the BLA in enabling the reinstatement of alcohol-seeking driven by an alcohol context. PMID:23758059

Modelling fungal solid-state fermentation: The role of inactivation kinetics

NARCIS (Netherlands)

Smits, J.P.; Sonsbeek, H.M. van; Knol, W.; Tramper, J.; Geelhoed, W.; Peeters, M.; Rinzema, A.

1999-01-01

The theoretical mathematical models described in this paper are used to evaluate the effects of fungal biomass inactivation kinetics on a non- isothermal tray solid-state fermentation (SSF). The inactivation kinetics, derived from previously reported experiments done under isothermal conditions and

Structure of suicide-inactivated β-hydroxydecanoyl-thioester dehydrase

International Nuclear Information System (INIS)

Schwab, J.M.; Ho, C.K.; Li, W.B.; Townsend, C.A.; Salituro, G.M.

1986-01-01

β-Hydroxydecanoylthioester dehydrase, the key enzyme in biosynthesis of unsaturated fatty acids under anaerobic conditions, equilibrates thioesters of (R)-3-hydroxydecanoic acid, E-2-decenoic acid, and Z-3-decenoic acid. Dehydrase is irreversibly inactivated by the N-acetylcysteamine thioester of 3-decynoic acid (3-decynoyl-NAC), via dehydrase-catalyzed isomerization to 2,3-decadienoyl-NAC. To probe the relationship between normal catalysis and suicide inactivation, the structure of the inactivated enzyme has been studied. 3-[2- 13 C]Decynoyl-NAC was synthesized and incubated with dehydrase. 13 C NMR showed that attack of 2,3-decadienoyl-NAC by the active site histidine gives 3-histidinyl-3-decenoyl-NAC, which slowly rearranges to the more stable Δ 2 isomer. Model histidine-allene adducts have been made and characterized. Analysis of NMR data show that the C=C configuration of the decenoyl moiety of enzyme-bound inactivator is E. The suggestion that the mechanism of dehydrase inactivation parallels its normal mechanism of action is supported these findings

Cholinergic Inputs from Basal Forebrain Add an Excitatory Bias to Odor Coding in the Olfactory Bulb

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Rothermel, Markus; Carey, Ryan M.; Puche, Adam; Shipley, Michael T.

2014-01-01

Cholinergic modulation of central circuits is associated with active sensation, attention, and learning, yet the neural circuits and temporal dynamics underlying cholinergic effects on sensory processing remain unclear. Understanding the effects of cholinergic modulation on particular circuits is complicated by the widespread projections of cholinergic neurons to telencephalic structures that themselves are highly interconnected. Here we examined how cholinergic projections from basal forebrain to the olfactory bulb (OB) modulate output from the first stage of sensory processing in the mouse olfactory system. By optogenetically activating their axons directly in the OB, we found that cholinergic projections from basal forebrain regulate OB output by increasing the spike output of presumptive mitral/tufted cells. Cholinergic stimulation increased mitral/tufted cell spiking in the absence of inhalation-driven sensory input and further increased spiking responses to inhalation of odorless air and to odorants. This modulation was rapid and transient, was dependent on local cholinergic signaling in the OB, and differed from modulation by optogenetic activation of cholinergic neurons in basal forebrain, which led to a mixture of mitral/tufted cell excitation and suppression. Finally, bulbar cholinergic enhancement of mitral/tufted cell odorant responses was robust and occurred independent of the strength or even polarity of the odorant-evoked response, indicating that cholinergic modulation adds an excitatory bias to mitral/tufted cells as opposed to increasing response gain or sharpening response spectra. These results are consistent with a role for the basal forebrain cholinergic system in dynamically regulating the sensitivity to or salience of odors during active sensing of the olfactory environment. PMID:24672011

Cerebrovascular endothelin-1 hyper-reactivity is associated with transient receptor potential canonical channels 1 and 6 activation and delayed cerebral hypoperfusion after forebrain ischaemia in rats

DEFF Research Database (Denmark)

Johansson, S E; Andersen, X E D R; Hansen, R H

2015-01-01

. METHODS: Experimental forebrain ischaemia was induced in Wistar male rats by a two-vessel occlusion model, and the cerebral blood flow was measured by magnetic resonance imaging two days after reperfusion. In vitro vasoreactivity studies, immunofluorescence and quantitative PCR were performed on cerebral...... in the vascular smooth muscle cells was enhanced and correlated with decreased cerebral blood flow two days after forebrain ischaemia. Furthermore, under conditions when voltage-dependent calcium channels were inhibited, endothelin-1-induced cerebrovascular contraction was enhanced and this enhancement...... was presumably mediated by Ca(2+) influx via upregulated transient receptor potential canonical channels 1 and 6. CONCLUSIONS: Our data demonstrates that endothelin-1-mediated influx of extracellular Ca(2+) activates transient receptor potential canonical channels 1 and 6 in cerebral vascular smooth muscle cells...

The hallucinogen d-lysergic acid diethylamide (d-LSD) induces the immediate-early gene c-Fos in rat forebrain.

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Frankel, Paul S; Cunningham, Kathryn A

2002-12-27

The hallucinogen d-lysergic acid diethylamide (d-LSD) evokes dramatic somatic and psychological effects. In order to analyze the neural activation induced by this unique psychoactive drug, we tested the hypothesis that expression of the immediate-early gene product c-Fos is induced in specific regions of the rat forebrain by a relatively low, behaviorally active, dose of d-LSD (0.16 mg/kg, i.p.); c-Fos protein expression was assessed at 30 min, and 1, 2 and 4 h following d-LSD injection. A time- and region-dependent expression of c-Fos was observed with a significant increase (PLSD administration. These data demonstrate a unique pattern of c-Fos expression in the rat forebrain following a relatively low dose of d-LSD and suggest that activation of these forebrain regions contributes to the unique behavioral effects of d-LSD. Copyright 2002 Elsevier Science B.V.

Forebrain-Specific Loss of BMPRII in Mice Reduces Anxiety and Increases Object Exploration.

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McBrayer, Zofeyah L; Dimova, Jiva; Pisansky, Marc T; Sun, Mu; Beppu, Hideyuki; Gewirtz, Jonathan C; O'Connor, Michael B

2015-01-01

To investigate the role of Bone Morphogenic Protein Receptor Type II (BMPRII) in learning, memory, and exploratory behavior in mice, a tissue-specific knockout of BMPRII in the post-natal hippocampus and forebrain was generated. We found that BMPRII mutant mice had normal spatial learning and memory in the Morris water maze, but showed significantly reduced swimming speeds with increased floating behavior. Further analysis using the Porsolt Swim Test to investigate behavioral despair did not reveal any differences in immobility between mutants and controls. In the Elevated Plus Maze, BMPRII mutants and Smad4 mutants showed reduced anxiety, while in exploratory tests, BMPRII mutants showed more interest in object exploration. These results suggest that loss of BMPRII in the mouse hippocampus and forebrain does not disrupt spatial learning and memory encoding, but instead impacts exploratory and anxiety-related behaviors.

Forebrain-Specific Loss of BMPRII in Mice Reduces Anxiety and Increases Object Exploration.

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Zofeyah L McBrayer

Full Text Available To investigate the role of Bone Morphogenic Protein Receptor Type II (BMPRII in learning, memory, and exploratory behavior in mice, a tissue-specific knockout of BMPRII in the post-natal hippocampus and forebrain was generated. We found that BMPRII mutant mice had normal spatial learning and memory in the Morris water maze, but showed significantly reduced swimming speeds with increased floating behavior. Further analysis using the Porsolt Swim Test to investigate behavioral despair did not reveal any differences in immobility between mutants and controls. In the Elevated Plus Maze, BMPRII mutants and Smad4 mutants showed reduced anxiety, while in exploratory tests, BMPRII mutants showed more interest in object exploration. These results suggest that loss of BMPRII in the mouse hippocampus and forebrain does not disrupt spatial learning and memory encoding, but instead impacts exploratory and anxiety-related behaviors.

Effective Thermal Inactivation of the Spores of Bacillus cereus Biofilms Using Microwave.

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Park, Hyong Seok; Yang, Jungwoo; Choi, Hee Jung; Kim, Kyoung Heon

2017-07-28

Microwave sterilization was performed to inactivate the spores of biofilms of Bacillus cereus involved in foodborne illness. The sterilization conditions, such as the amount of water and the operating temperature and treatment time, were optimized using statistical analysis based on 15 runs of experimental results designed by the Box-Behnken method. Statistical analysis showed that the optimal conditions for the inactivation of B. cereus biofilms were 14 ml of water, 108°C of temperature, and 15 min of treatment time. Interestingly, response surface plots showed that the amount of water is the most important factor for microwave sterilization under the present conditions. Complete inactivation by microwaves was achieved in 5 min, and the inactivation efficiency by microwave was obviously higher than that by conventional steam autoclave. Finally, confocal laser scanning microscopy images showed that the principal effect of microwave treatment was cell membrane disruption. Thus, this study can contribute to the development of a process to control food-associated pathogens.

Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation

International Nuclear Information System (INIS)

Elliott, L.H.; McCormick, J.B.; Johnson, K.M.

1982-01-01

Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with 60 CO gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of 60 CO radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. The authors found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents

Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation

International Nuclear Information System (INIS)

Elliott, L.H.; McCormick, J.B.; Johnson, K.M.

1982-01-01

Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with 60 Co gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of 60 Co radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. We found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents

Dcc regulates asymmetric outgrowth of forebrain neurons in zebrafish.

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Jingxia Gao

Full Text Available The guidance receptor DCC (deleted in colorectal cancer ortholog UNC-40 regulates neuronal asymmetry development in Caenorhabditis elegans, but it is not known whether DCC plays a role in the specification of neuronal polarity in vertebrates. To examine the roles of DCC in neuronal asymmetry regulation in vertebrates, we studied zebrafish anterior dorsal telencephalon (ADt neuronal axons. We generated transgenic zebrafish animals expressing the photo-convertible fluorescent protein Kaede in ADt neurons and then photo-converted Kaede to label specifically the ADt neuron axons. We found that ADt axons normally project ventrally. Knock down of Dcc function by injecting antisense morpholino oligonucleotides caused the ADt neurons to project axons dorsally. To examine the axon projection pattern of individual ADt neurons, we labeled single ADt neurons using a forebrain-specific promoter to drive fluorescent protein expression. We found that individual ADt neurons projected axons dorsally or formed multiple processes after morpholino knock down of Dcc function. We further found that knock down of the Dcc ligand, Netrin1, also caused ADt neurons to project axons dorsally. Knockdown of Neogenin1, a guidance receptor closely related to Dcc, enhanced the formation of aberrant dorsal axons in embryos injected with Dcc morpholino. These experiments provide the first evidence that Dcc regulates polarized axon initiation and asymmetric outgrowth of forebrain neurons in vertebrates.

ESC-Derived Basal Forebrain Cholinergic Neurons Ameliorate the Cognitive Symptoms Associated with Alzheimer’s Disease in Mouse Models

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Wei Yue

2015-11-01

Full Text Available Degeneration of basal forebrain cholinergic neurons (BFCNs is associated with cognitive impairments of Alzheimer’s disease (AD, implying that BFCNs hold potentials in exploring stem cell-based replacement therapy for AD. However, studies on derivation of BFCNs from embryonic stem cells (ESCs are limited, and the application of ESC-derived BFCNs remains to be determined. Here, we report on differentiation approaches for directing both mouse and human ESCs into mature BFCNs. These ESC-derived BFCNs exhibit features similar to those of their in vivo counterparts and acquire appropriate functional properties. After transplantation into the basal forebrain of AD model mice, ESC-derived BFCN progenitors predominantly differentiate into mature cholinergic neurons that functionally integrate into the endogenous basal forebrain cholinergic projection system. The AD mice grafted with mouse or human BFCNs exhibit improvements in learning and memory performances. Our findings suggest a promising perspective of ESC-derived BFCNs in the development of stem cell-based therapies for treatment of AD.

Song exposure regulates known and novel microRNAs in the zebra finch auditory forebrain

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Kim Jong H

2011-05-01

Full Text Available Abstract Background In an important model for neuroscience, songbirds learn to discriminate songs they hear during tape-recorded playbacks, as demonstrated by song-specific habituation of both behavioral and neurogenomic responses in the auditory forebrain. We hypothesized that microRNAs (miRNAs or miRs may participate in the changing pattern of gene expression induced by song exposure. To test this, we used massively parallel Illumina sequencing to analyse small RNAs from auditory forebrain of adult zebra finches exposed to tape-recorded birdsong or silence. Results In the auditory forebrain, we identified 121 known miRNAs conserved in other vertebrates. We also identified 34 novel miRNAs that do not align to human or chicken genomes. Five conserved miRNAs showed significant and consistent changes in copy number after song exposure across three biological replications of the song-silence comparison, with two increasing (tgu-miR-25, tgu-miR-192 and three decreasing (tgu-miR-92, tgu-miR-124, tgu-miR-129-5p. We also detected a locus on the Z sex chromosome that produces three different novel miRNAs, with supporting evidence from Northern blot and TaqMan qPCR assays for differential expression in males and females and in response to song playbacks. One of these, tgu-miR-2954-3p, is predicted (by TargetScan to regulate eight song-responsive mRNAs that all have functions in cellular proliferation and neuronal differentiation. Conclusions The experience of hearing another bird singing alters the profile of miRNAs in the auditory forebrain of zebra finches. The response involves both known conserved miRNAs and novel miRNAs described so far only in the zebra finch, including a novel sex-linked, song-responsive miRNA. These results indicate that miRNAs are likely to contribute to the unique behavioural biology of learned song communication in songbirds.

A frontal cortex event-related potential driven by the basal forebrain

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Nguyen, David P; Lin, Shih-Chieh

2014-01-01

Event-related potentials (ERPs) are widely used in both healthy and neuropsychiatric conditions as physiological indices of cognitive functions. Contrary to the common belief that cognitive ERPs are generated by local activity within the cerebral cortex, here we show that an attention-related ERP in the frontal cortex is correlated with, and likely generated by, subcortical inputs from the basal forebrain (BF). In rats performing an auditory oddball task, both the amplitude and timing of the frontal ERP were coupled with BF neuronal activity in single trials. The local field potentials (LFPs) associated with the frontal ERP, concentrated in deep cortical layers corresponding to the zone of BF input, were similarly coupled with BF activity and consistently triggered by BF electrical stimulation within 5–10 msec. These results highlight the important and previously unrecognized role of long-range subcortical inputs from the BF in the generation of cognitive ERPs. DOI: http://dx.doi.org/10.7554/eLife.02148.001 PMID:24714497

Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB1 receptors and apoptotic cell death

International Nuclear Information System (INIS)

Tomiyama, Ken-ichi; Funada, Masahiko

2014-01-01

The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB 1 receptor antagonist AM251, but not with the selective CB 2 receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB 1 receptor, but not by the CB 2 receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: • Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. • Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB 1 receptor, but not by the CB 2 receptor, and involves caspase-dependent apoptosis. • A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB 1 receptors

Effect of post-treatment conditions on the inactivation of helminth eggs (Ascaris suum) after the composting process.

Science.gov (United States)

Darimani, Hamidatu S; Ito, Ryusei; Maiga, Ynoussa; Sou, Mariam; Funamizu, Naoyuki; Maiga, Amadou H

2016-01-01

Safe and appropriate disposal of human waste is a basic requirement for sanitation and protection of public health. For proper sanitation and nutrient recovery, it is necessary to ensure effective treatment methods to complete pathogen destruction in excreta prior to reuse. Composting toilets convert faeces to a reusable resource such as fertilizer or humus for organic agriculture. A composting toilet for rural Burkina Faso was created by modifying a commercial model available in Japan to improve hygiene and increase food production. The toilet has shown to result in a degraded final product, but its effectiveness for pathogen destruction was unclear due to low temperatures generated from the toilet. This study aimed to sanitize compost withdrawn from the composting toilet for food production by setting post-treatment conditions. The inactivation kinetics of Ascaris suum eggs, selected as an indicator for helminth eggs, was determined during post-treatment at different temperatures (30°C, 40°C, 50°C and 60°C) with varying moisture contents (MC) (50%, 60% and 70%). The treatment of compost in a possible additional post-treatment after the composting process was tried in the laboratory test. Inactivation of A. suum eggs was fast with greater than two log reductions achieved within 2 h for temperature 50°C and 50% MC and greater than three log reductions for temperature 60°C and 50% MC within 3 h. Statistical analysis showed the significant impact of temperature and moisture on the inactivation rates of A. suum eggs. The post-treatment can efficiently increase helminth eggs destruction prior to reuse.

Visual training paired with electrical stimulation of the basal forebrain improves orientation-selective visual acuity in the rat.

Science.gov (United States)

Kang, Jun Il; Groleau, Marianne; Dotigny, Florence; Giguère, Hugo; Vaucher, Elvire

2014-07-01

The cholinergic afferents from the basal forebrain to the primary visual cortex play a key role in visual attention and cortical plasticity. These afferent fibers modulate acute and long-term responses of visual neurons to specific stimuli. The present study evaluates whether this cholinergic modulation of visual neurons results in cortical activity and visual perception changes. Awake adult rats were exposed repeatedly for 2 weeks to an orientation-specific grating with or without coupling this visual stimulation to an electrical stimulation of the basal forebrain. The visual acuity, as measured using a visual water maze before and after the exposure to the orientation-specific grating, was increased in the group of trained rats with simultaneous basal forebrain/visual stimulation. The increase in visual acuity was not observed when visual training or basal forebrain stimulation was performed separately or when cholinergic fibers were selectively lesioned prior to the visual stimulation. The visual evoked potentials show a long-lasting increase in cortical reactivity of the primary visual cortex after coupled visual/cholinergic stimulation, as well as c-Fos immunoreactivity of both pyramidal and GABAergic interneuron. These findings demonstrate that when coupled with visual training, the cholinergic system improves visual performance for the trained orientation probably through enhancement of attentional processes and cortical plasticity in V1 related to the ratio of excitatory/inhibitory inputs. This study opens the possibility of establishing efficient rehabilitation strategies for facilitating visual capacity.

Inactivation of infectious bovine rhinotracheitis virus by gamma irradiation

International Nuclear Information System (INIS)

Nonomiya, Takashi; Yamashiro, Tomio; Tsutsumi, Takamasa; Ito, Hitoshi; Ishigaki, Isao.

1990-01-01

Radiation inactivation of Infectious Boivne Rhinotracheitis (IBR) virus was investigated by suspending in a commercial preparation medium (c.p.m.) or IBR antibody free serum and irradiated at room temperature or dry ice frozen condition. Normal pooled serum was also analysed by electrophoresis with cellulose acetate membrane after irradiation at frozen and non-frozen condition. The virus inactivation was determined by MDBK cell line which 50 % tissue culture infectious dose (TCID 50 ) was calculated by Behrens Kaerber method. D 10 value at non-frozen condition in serum was obtained as 1.1-1.2 kGy and that in c.p.m. was 1.3-1.4 kGy. On the other hand, D 10 value was increased to 3.4-3.6 kGy in serum and 3.9 kGy in c.p.m. at frozen condition. On the irradiation effect of bovine serum, four peaks of albumin, α, β and γ-globulin fraction were obtained from non-irradiation and irradiated serum up to 2 kGy at non-frozen condition by electrophoresis. More than 4 kGy irradiation, the peaks of globulin fractions became not clear and at more than 8 kGy, changed to one large peak. On the other hand, these changes of electrophoretic patterns were not observed even at 30 kGy irradiation in frozen condition. From these results, necessary dose was decided as 20-25 kGy at frozen condition for inactivation of IBR virus in serum. (author)

Radiation inactivation of microorganisms on food materials with different dry conditions

International Nuclear Information System (INIS)

Ryomoto, Yasuhisa; Ito, Hitoshi

2001-01-01

The effect of dry condition of food materials such as spices or herbs with grain or powder were investigated for inactivation of microorganisms by gamma-rays or electron-beams. Radiation sensitivities on endospores of Bacillus pumilus and B. cereus at polished rice, whole black pepper and glass fiber filter dried with additives of 2% peptone + 1% glycerin were almost equivalent, and D 10 values of gamma-rays were obtained to be 1.8 - 2.2 kGy for B. pumilus and 1.2 - 1.3 kGy for B. cereus, respectively. However, D 10 value was decreased to 1.6 kGy for B. pumilus and 1.0 kGy for B. cereus in white pepper powder, and increased significantly as 2.6 kGy for B. pumilus and 1.8 kGy for B. cereus in senna herb powder. In the case of B. megaterium, Enterobacter cloacae and Escherichia coli, D 10 values were increased at all of food materials even in white pepper powder compared with glass fiber filter with additives. These results are indicating that glycerin and related radical scavengers in food components protect the bacteria such as B. megaterium, Ent. cloacae and E. coli more significantly from effects of radiation than B. pumilus or B. cereus. The increase of radiation resistance of these bacteria should be responsible also to the amount of oxygen penetration in bacterial cells which dried at different conditions. On the irradiation of electron-beams, radiation resistance of all of bacteria increased more significantly than gamma-rays which depending to dose rate effects on bacteria. However, increase of radiation resistance was not observed at Aspergillus oryzae in all of food materials at different dry conditions. (author)

Radiation inactivation of microorganisms on food materials with different dry conditions

Energy Technology Data Exchange (ETDEWEB)

Ryomoto, Yasuhisa; Ito, Hitoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2001-09-01

The effect of dry condition of food materials such as spices or herbs with grain or powder were investigated for inactivation of microorganisms by gamma-rays or electron-beams. Radiation sensitivities on endospores of Bacillus pumilus and B. cereus at polished rice, whole black pepper and glass fiber filter dried with additives of 2% peptone + 1% glycerin were almost equivalent, and D{sub 10} values of gamma-rays were obtained to be 1.8 - 2.2 kGy for B. pumilus and 1.2 - 1.3 kGy for B. cereus, respectively. However, D{sub 10} value was decreased to 1.6 kGy for B. pumilus and 1.0 kGy for B. cereus in white pepper powder, and increased significantly as 2.6 kGy for B. pumilus and 1.8 kGy for B. cereus in senna herb powder. In the case of B. megaterium, Enterobacter cloacae and Escherichia coli, D{sub 10} values were increased at all of food materials even in white pepper powder compared with glass fiber filter with additives. These results are indicating that glycerin and related radical scavengers in food components protect the bacteria such as B. megaterium, Ent. cloacae and E. coli more significantly from effects of radiation than B. pumilus or B. cereus. The increase of radiation resistance of these bacteria should be responsible also to the amount of oxygen penetration in bacterial cells which dried at different conditions. On the irradiation of electron-beams, radiation resistance of all of bacteria increased more significantly than gamma-rays which depending to dose rate effects on bacteria. However, increase of radiation resistance was not observed at Aspergillus oryzae in all of food materials at different dry conditions. (author)

Inactivation of Mycobacterium avium with free chlorine.

Science.gov (United States)

Luh, Jeanne; Mariñas, Benito J

2007-07-15

The inactivation kinetics of Mycobacterium avium with free chlorine was characterized by two stages: an initial phase at a relatively fast rate followed by a slower second stage of pseudo first-order kinetics. The inactivation rate of each stage was approximately the same for all experiments performed at a certain condition of pH and temperature; however, variability was observed for the disinfectant exposure at which the transition between the two stages occurred. This variability was not a function of the initial disinfectant concentration, the initial bacterial density, or the bacterial stock. However, the transition to the second stage varied more significantly at high temperatures (30 degrees C), while lower variability was observed at lower temperatures (5 and 20 degrees C). Experiments conducted at pH values in the range of 6-9 revealed that the inactivation of M. avium was primarily due to hypochlorous acid, with little contribution from hypochlorite ion within this pH range. The inactivation kinetics was represented with a two-population model. The activation energies for the resulting pseudo first-order rate constants for the populations with fast and slow kinetics were 100.3 and 96.5 kJ/mol, respectively. The magnitude of these values suggested that for waters of relatively high pH and low temperatures, little inactivation of M. avium would be achieved within treatment plants, providing a seeding source for distribution systems.

Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB{sub 1} receptors and apoptotic cell death

Energy Technology Data Exchange (ETDEWEB)

Tomiyama, Ken-ichi; Funada, Masahiko, E-mail: mfunada@ncnp.go.jp

2014-01-01

The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB{sub 1} receptor antagonist AM251, but not with the selective CB{sub 2} receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: • Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. • Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and involves caspase-dependent apoptosis. • A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB{sub 1} receptors.

Forebrain development in fetal MRI: evaluation of anatomical landmarks before gestational week 27

International Nuclear Information System (INIS)

Schmook, Maria T.; Weber, Michael; Kasprian, Gregor; Nemec, Stefan; Prayer, Daniela; Brugger, Peter C.; Krampl-Bettelheim, Elisabeth

2010-01-01

Forebrain malformations include some of the most severe developmental anomalies and require early diagnosis. The proof of normal or abnormal prosencephalic development may have an influence on further management in the event of a suspected fetal malformation. The purpose of this retrospective study was to evaluate the detectability of anatomical landmarks of forebrain development using in vivo fetal magnetic resonance imaging (MRI) before gestational week (gw) 27. MRI studies of 83 singleton fetuses (gw 16-26, average ±sd: gw 22 ± 2) performed at 1.5 Tesla were assessed. T2-weighted (w) fast spin echo, T1w gradient-echo and diffusion-weighted sequences were screened for the detectability of anatomical landmarks as listed below. The interhemispheric fissure, ocular bulbs, corpus callosum, infundibulum, chiasm, septum pellucidum (SP), profile, and palate were detectable in 95%, 95%, 89%, 87%, 82%, 81%, 78%, 78% of cases. Olfactory tracts were more easily delineated than bulbs and sulci (37% versus 18% and 8%), with significantly higher detection rates in the coronal plane. The pituitary gland could be detected on T1w images in 60% with an increasing diameter with gestational age (p=0.041). The delineation of olfactory tracts (coronal plane), chiasm, SP and pituitary gland were significantly increased after week 21 (p<0.05). Pathologies were found in 28% of cases. This study provides detection rates for anatomical landmarks of forebrain development with fetal MRI before gw 27. Several anatomical structures are readily detectable with routine fetal MRI sequences; thus, if these landmarks are not delineable, it should raise the suspicion of a pathology. Recommendations regarding favorable sequences/planes are provided. (orig.)

Forebrain development in fetal MRI: evaluation of anatomical landmarks before gestational week 27

Energy Technology Data Exchange (ETDEWEB)

Schmook, Maria T.; Weber, Michael; Kasprian, Gregor; Nemec, Stefan; Prayer, Daniela [Medical University of Vienna, Department of Radiology/Division of Neuro- and Musculoskeletal Radiology, Vienna (Austria); Brugger, Peter C. [Medical University of Vienna, Integrative Morphology Group, Center for Anatomy and Cell Biology, Vienna (Austria); Krampl-Bettelheim, Elisabeth [Department of Obstetrics and Gynecology / Division of Obstetrics and Feto-maternal Medicine, Vienna (Austria)

2010-06-15

Forebrain malformations include some of the most severe developmental anomalies and require early diagnosis. The proof of normal or abnormal prosencephalic development may have an influence on further management in the event of a suspected fetal malformation. The purpose of this retrospective study was to evaluate the detectability of anatomical landmarks of forebrain development using in vivo fetal magnetic resonance imaging (MRI) before gestational week (gw) 27. MRI studies of 83 singleton fetuses (gw 16-26, average {+-}sd: gw 22 {+-} 2) performed at 1.5 Tesla were assessed. T2-weighted (w) fast spin echo, T1w gradient-echo and diffusion-weighted sequences were screened for the detectability of anatomical landmarks as listed below. The interhemispheric fissure, ocular bulbs, corpus callosum, infundibulum, chiasm, septum pellucidum (SP), profile, and palate were detectable in 95%, 95%, 89%, 87%, 82%, 81%, 78%, 78% of cases. Olfactory tracts were more easily delineated than bulbs and sulci (37% versus 18% and 8%), with significantly higher detection rates in the coronal plane. The pituitary gland could be detected on T1w images in 60% with an increasing diameter with gestational age (p=0.041). The delineation of olfactory tracts (coronal plane), chiasm, SP and pituitary gland were significantly increased after week 21 (p<0.05). Pathologies were found in 28% of cases. This study provides detection rates for anatomical landmarks of forebrain development with fetal MRI before gw 27. Several anatomical structures are readily detectable with routine fetal MRI sequences; thus, if these landmarks are not delineable, it should raise the suspicion of a pathology. Recommendations regarding favorable sequences/planes are provided. (orig.)

High pressure inactivation of Brettanomyces bruxellensis in red wine.

Science.gov (United States)

van Wyk, Sanelle; Silva, Filipa V M

2017-05-01

Brettanomyces bruxellensis ("Brett") is a major spoilage concern for the wine industry worldwide, leading to undesirable sensory properties. Sulphur dioxide, is currently the preferred method for wine preservation. However, due to its negative effects on consumers, the use of new alternative non-thermal technologies are increasingly being investigated. The aim of this study was to determine and model the effect of high pressure processing (HPP) conditions and yeast strain on the inactivation of "Brett" in Cabernet Sauvignon wine. Processing at 200 MPa for 3 min resulted in 5.8 log reductions. However higher pressure is recommended to achieve high throughput in the wine industry, for example >6.0 log reductions were achieved after 400 MPa for 5 s. The inactivation of B. bruxellensis is pressure and time dependent, with increased treatment time and pressure leading to increased yeast inactivation. It was also found that yeast strain had a significant effect on HPP inactivation, with AWRI 1499 being the most resistant strain. The Weibull model successfully described the HPP "Brett" inactivation. HPP is a viable alternative for the inactivation of B. bruxellensis in wine, with the potential to reduce the industry's reliance on sulphur dioxide. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mechanisms of poliovirus inactivation by the direct and indirect effects of ionizing radiation

International Nuclear Information System (INIS)

Ward, R.L.

1980-01-01

This study was designed to measure the effects of ionizing radiation on poliovirus particles when given under conditions where either direct (in broth) or indirect (in water) effects were predominant. Under direct conditions, inactivation of poliovirus was found to be due primarily to RNA damage, although capsid damage could account for about one-third of the viral inactivation. RNA damage did not appear to be due to strand breakage and therefore was probably caused primarily by base damage or crosslink formation. Capsid damage under direct irradiation conditions did not result in significant alterations of either the sedimentation coefficients or the isoelectric points of the poliovirus particles or detectable modification of the sizes of the viral proteins. It did, however, cause loss of availability to bind to host cells. Under indirect conditions no more than 25% of viral inactivation appeared to be due to RNA damage. However, the sedimentation coefficients and isoelectric points of the viral particles were greatly altered, and their abilities to bind to cells were lost at about three-fourths the rate of loss of infectivity. Capsid damage in this case did result in changes in the sizes of capsid proteins. Therefore, the majority of the radiation inactivation under indirect conditions appeared to be due to protein damage

Forebrain deletion of αGDI in adult mice worsens the pre-synaptic deficit at cortico-lateral amygdala synaptic connections.

Directory of Open Access Journals (Sweden)

Veronica Bianchi

Full Text Available The GDI1 gene encodes αGDI, which retrieves inactive GDP-bound RAB from membranes to form a cytosolic pool awaiting vesicular release. Mutations in GDI1 are responsible for X-linked Intellectual Disability. Characterization of the Gdi1-null mice has revealed alterations in the total number and distribution of hippocampal and cortical synaptic vesicles, hippocampal short-term synaptic plasticity and specific short-term memory deficits in adult mice, which are possibly caused by alterations of different synaptic vesicle recycling pathways controlled by several RAB GTPases. However, interpretation of these studies is complicated by the complete ablation of Gdi1 in all cells in the brain throughout development. In this study, we generated conditionally gene-targeted mice in which the knockout of Gdi1 is restricted to the forebrain, hippocampus, cortex and amygdala and occurs only during postnatal development. Adult mutant mice reproduce the short-term memory deficit previously reported in Gdi1-null mice. Surprisingly, the delayed ablation of Gdi1 worsens the pre-synaptic phenotype at cortico-amygdala synaptic connections compared to Gdi1-null mice. These results suggest a pivotal role of αGDI via specific RAB GTPases acting specifically in forebrain regions at the pre-synaptic sites involved in memory formation.

Lipase inactivation in wheat germ by gamma irradiation

International Nuclear Information System (INIS)

Jha, Pankaj Kumar; Kudachikar, V.B.; Kumar, Sourav

2013-01-01

An attempt was made to improve the shelf life of wheat germ by optimizing processing conditions involving γ-irradiation. Studies were carried out to investigate the effect of γ-irradiation (0–30 kGy doses) on the chemical composition of wheat germ with respect to variation in moisture, total ash, crude fat, free fatty acid, protein and lipase activity. The results demonstrate that shelf stability of wheat germ was achieved by inactivation of lipase at doses of γ-irradiation greater than 12 kGy. - Highlights: Ø γ-irradiation was found to inactivate Lipase present in Wheat Germ. Ø The treatment did not result in significant changes in Total Ash, Moisture and Protein Content of Wheat Germ. Ø The irradiation at 30 kGy resulted in 31.2 % inactivation of Lipase in Wheat Germ

Inactivation of infectious bovine rhinotracheitis virus by gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Nonomiya, Takashi; Yamashiro, Tomio; Tsutsumi, Takamasa (Animal Quarantine Service, Yokohama (Japan)); Ito, Hitoshi; Ishigaki, Isao

1990-10-01

Radiation inactivation of Infectious Boivne Rhinotracheitis (IBR) virus was investigated by suspending in a commercial preparation medium (c.p.m.) or IBR antibody free serum and irradiated at room temperature or dry ice frozen condition. Normal pooled serum was also analysed by electrophoresis with cellulose acetate membrane after irradiation at frozen and non-frozen condition. The virus inactivation was determined by MDBK cell line which 50 % tissue culture infectious dose (TCID{sub 50}) was calculated by Behrens Kaerber method. D{sub 10} value at non-frozen condition in serum was obtained as 1.1-1.2 kGy and that in c.p.m. was 1.3-1.4 kGy. On the other hand, D{sub 10} value was increased to 3.4-3.6 kGy in serum and 3.9 kGy in c.p.m. at frozen condition. On the irradiation effect of bovine serum, four peaks of albumin, {alpha}, {beta} and {gamma}-globulin fraction were obtained from non-irradiation and irradiated serum up to 2 kGy at non-frozen condition by electrophoresis. More than 4 kGy irradiation, the peaks of globulin fractions became not clear and at more than 8 kGy, changed to one large peak. On the other hand, these changes of electrophoretic patterns were not observed even at 30 kGy irradiation in frozen condition. From these results, necessary dose was decided as 20-25 kGy at frozen condition for inactivation of IBR virus in serum. (author).

Acute reversible inactivation of the bed nucleus of stria terminalis induces antidepressant-like effect in the rat forced swimming test

Science.gov (United States)

2010-01-01

Background The bed nucleus of stria terminalis (BNST) is a limbic forebrain structure involved in hypothalamo-pituitary-adrenal axis regulation and stress adaptation. Inappropriate adaptation to stress is thought to compromise the organism's coping mechanisms, which have been implicated in the neurobiology of depression. However, the studies aimed at investigating BNST involvement in depression pathophysiology have yielded contradictory results. Therefore, the objective of the present study was to investigate the effects of temporary acute inactivation of synaptic transmission in the BNST by local microinjection of cobalt chloride (CoCl2) in rats subjected to the forced swimming test (FST). Methods Rats implanted with cannulae aimed at the BNST were submitted to 15 min of forced swimming (pretest). Twenty-four hours later immobility time was registered in a new 5 min forced swimming session (test). Independent groups of rats received bilateral microinjections of CoCl2 (1 mM/100 nL) before or immediately after pretest or before the test session. Additional groups received the same treatment and were submitted to the open field test to control for unspecific effects on locomotor behavior. Results CoCl2 injection into the BNST before either the pretest or test sessions reduced immobility in the FST, suggesting an antidepressant-like effect. No significant effect of CoCl2 was observed when it was injected into the BNST immediately after pretest. In addition, no effect of BNST inactivation was observed in the open field test. Conclusion These results suggest that acute reversible inactivation of synaptic transmission in the BNST facilitates adaptation to stress and induces antidepressant-like effects. PMID:20515458

Acute reversible inactivation of the bed nucleus of stria terminalis induces antidepressant-like effect in the rat forced swimming test

Directory of Open Access Journals (Sweden)

Joca Sâmia RL

2010-06-01

Full Text Available Abstract Background The bed nucleus of stria terminalis (BNST is a limbic forebrain structure involved in hypothalamo-pituitary-adrenal axis regulation and stress adaptation. Inappropriate adaptation to stress is thought to compromise the organism's coping mechanisms, which have been implicated in the neurobiology of depression. However, the studies aimed at investigating BNST involvement in depression pathophysiology have yielded contradictory results. Therefore, the objective of the present study was to investigate the effects of temporary acute inactivation of synaptic transmission in the BNST by local microinjection of cobalt chloride (CoCl2 in rats subjected to the forced swimming test (FST. Methods Rats implanted with cannulae aimed at the BNST were submitted to 15 min of forced swimming (pretest. Twenty-four hours later immobility time was registered in a new 5 min forced swimming session (test. Independent groups of rats received bilateral microinjections of CoCl2 (1 mM/100 nL before or immediately after pretest or before the test session. Additional groups received the same treatment and were submitted to the open field test to control for unspecific effects on locomotor behavior. Results CoCl2 injection into the BNST before either the pretest or test sessions reduced immobility in the FST, suggesting an antidepressant-like effect. No significant effect of CoCl2 was observed when it was injected into the BNST immediately after pretest. In addition, no effect of BNST inactivation was observed in the open field test. Conclusion These results suggest that acute reversible inactivation of synaptic transmission in the BNST facilitates adaptation to stress and induces antidepressant-like effects.

Studies on the inactivation of human parvovirus 4.

Science.gov (United States)

Baylis, Sally A; Tuke, Philip W; Miyagawa, Eiji; Blümel, Johannes

2013-10-01

Human parvovirus 4 (PARV4) is a novel parvovirus, which like parvovirus B19 (B19V) can be a contaminant of plasma pools used to prepare plasma-derived medicinal products. Inactivation studies of B19V have shown that it is more sensitive to virus inactivation strategies than animal parvoviruses. However, inactivation of PARV4 has not yet been specifically addressed. Treatment of parvoviruses by heat or low-pH conditions causes externalization of the virus genome. Using nuclease treatment combined with real-time polymerase chain reaction, the extent of virus DNA externalization was used as an indirect measure of the inactivation of PARV4, B19V, and minute virus of mice (MVM) by pasteurization of albumin and by low-pH treatment. Infectivity studies were performed in parallel for B19V and MVM. PARV4 showed greater resistance to pasteurization and low-pH treatment than B19V, although PARV4 was not as resistant as MVM. There was a 2- to 3-log reduction of encapsidated PARV4 DNA after pasteurization and low-pH treatment. In contrast, B19V was effectively inactivated while MVM was stable under these conditions. Divalent cations were found to have a stabilizing effect on PARV4 capsids. In the absence of divalent cations, even at neutral pH, there was a reduction of PARV4 titer, an effect not observed for B19V or MVM. In the case of heat treatment and incubation at low pH, PARV4 shows intermediate resistance when compared to B19V and MVM. Divalent cations seem important for stabilizing PARV4 virus particles. © 2013 American Association of Blood Banks.

Extensive Lesions of Cholinergic Basal Forebrain Neurons Do Not Impair Spatial Working Memory

Science.gov (United States)

Vuckovich, Joseph A.; Semel, Mara E.; Baxter, Mark G.

2004-01-01

A recent study suggests that lesions to all major areas of the cholinergic basal forebrain in the rat (medial septum, horizontal limb of the diagonal band of Broca, and nucleus basalis magnocellularis) impair a spatial working memory task. However, this experiment used a surgical technique that may have damaged cerebellar Purkinje cells. The…

Inactivation Data.xlsx

Data.gov (United States)

U.S. Environmental Protection Agency — The data set is a spreadsheet that contains results of inactivation experiments that were conducted to to determine the effectiveness of chlorine in inactivating B....

Inactivation of human and simian rotaviruses by chlorine dioxide

Energy Technology Data Exchange (ETDEWEB)

Chen, Yu-Shiaw (Brookhaven National Lab., Upton, NY (USA)); Vaughn, J.M. (Univ. of New England College of Medicine, Biddeford, ME (USA))

1990-05-01

The inactivation of single-particle stocks of human (type 2, Wa) and simian (SA-11) rotaviruses by chlorine dioxide was investigated. Experiments were conducted at 4{degree}C in a standard phosphate-carbonate buffer. Both virus types were rapidly inactivated, within 20 s under alkaline conditions, when chlorine dioxide concentrations ranging from 0.05 to 0.2 mg/liter were used. Similar reductions of 10{sup 5}-fold in infectivity required additional exposure time of 120 s at 0.2 mg/liter for Wa and at 0.5 mg/liter for SA-11, respectively, at pH 6.0. The inactivation of both virus types was moderate a neutral pH, and the sensitivities to chlorine dioxide were similar. The observed enhancement of virucidal efficiency with increasing pH was contrary to earlier findings with chlorine- and ozone-treated rotavirus particles, where efficiencies decreased with increasing alkalinity. Comparison of 99.9% virus inactivation times revealed ozone to be the most effective virucidal agent among these three disinfectants.

Mechanism of Cd2+-coordination during Slow Inactivation in Potassium Channels

Science.gov (United States)

Raghuraman, H.; Cordero-Morales, Julio F.; Jogini, Vishwanath; Pan, Albert C.; Kollewe, Astrid; Roux, Benoît; Perozo, Eduardo

2013-01-01

Summary In K+ channels, rearrangements of the pore outer-vestibule have been associated with C-type inactivation gating. Paradoxically, the crystal structure of Open/C-type inactivated KcsA suggest these movements to be modest in magnitude. Here, we show that under physiological conditions, the KcsA outer-vestibule undergoes relatively large dynamic rearrangements upon inactivation. External Cd2+ enhances the rate of C-type inactivation in an outer-vestibule cysteine mutant (Y82C) via metal-bridge formation. This effect is not present in a non-inactivating mutant (E71A/Y82C). Tandem dimer and tandem tetramer constructs of equivalent cysteine mutants in KcsA and Shaker K+ channels demonstrate that these Cd2+ metal bridges are formed only between adjacent subunits. This is well supported by molecular dynamics simulations. Based on the crystal structure of Cd2+-bound Y82C-KcsA in the closed state, together with EPR distance measurements in the KcsA outer-vestibule, we suggest that subunits must dynamically come in close proximity as the channels undergo inactivation. PMID:22771214

Inactivation of pathogenic bacteria in food matrices: high pressure processing, photodynamic inactivation and pressure-assisted photodynamic inactivation

Science.gov (United States)

Cunha, A.; Couceiro, J.; Bonifácio, D.; Martins, C.; Almeida, A.; Neves, M. G. P. M. S.; Faustino, M. A. F.; Saraiva, J. A.

2017-09-01

Traditional food processing methods frequently depend on the application of high temperature. However, heat may cause undesirable changes in food properties and often has a negative impact on nutritional value and organoleptic characteristics. Therefore, reducing the microbial load without compromising the desirable properties of food products is still a technological challenge. High-pressure processing (HPP) can be classified as a cold pasteurization technique, since it is a non-thermal food preservation method that uses hydrostatic pressure to inactivate spoilage microorganisms. At the same time, it increases shelf life and retains the original features of food. Photodynamic inactivation (PDI) is also regarded as promising approach for the decontamination of food matrices. In this case, the inactivation of bacterial cells is achieved by the cytotoxic effects of reactive oxygens species (ROS) produced from the combined interaction of a photosensitizer molecule, light and oxygen. This short review examines some recent developments on the application of HPP and PDI with food-grade photosensitizers for the inactivation of listeriae, taken as a food pathogen model. The results of a proof-of-concept trial of the use of high-pressure as a coadjutant to increase the efficiency of photodynamic inactivation of bacterial endospores is also addressed.

Regulatory interactions of stress and reward on rat forebrain opioidergic and GABAergic circuitry.

Science.gov (United States)

Christiansen, A M; Herman, J P; Ulrich-Lai, Y M

2011-03-01

Palatable food intake reduces stress responses, suggesting that individuals may consume such ?comfort? food as self-medication for stress relief. The mechanism by which palatable foods provide stress relief is not known, but likely lies at the intersection of forebrain reward and stress regulatory circuits. Forebrain opioidergic and gamma-aminobutyric acid ergic signaling is critical for both reward and stress regulation, suggesting that these systems are prime candidates for mediating stress relief by palatable foods. Thus, the present study (1) determines how palatable ?comfort? food alters stress-induced changes in the mRNA expression of inhibitory neurotransmitters in reward and stress neurocircuitry and (2) identifies candidate brain regions that may underlie comfort food-mediated stress reduction. We used a model of palatable ?snacking? in combination with a model of chronic variable stress followed by in situ hybridization to determine forebrain levels of pro-opioid and glutamic acid decarboxylase (GAD) mRNA. The data identify regions within the extended amygdala, striatum, and hypothalamus as potential regions for mediating hypothalamic-pituitary-adrenal axis buffering following palatable snacking. Specifically, palatable snacking alone decreased pro-enkephalin-A (ENK) mRNA expression in the anterior bed nucleus of the stria terminalis (BST) and the nucleus accumbens, and decreased GAD65 mRNA in the posterior BST. Chronic stress alone increased ENK mRNA in the hypothalamus, nucleus accumbens, amygdala, and hippocampus; increased dynorphin mRNA in the nucleus accumbens; increased GAD65 mRNA in the anterior hypothalamus and BST; and decreased GAD65 mRNA in the dorsal hypothalamus. Importantly, palatable food intake prevented stress-induced gene expression changes in subregions of the hypothalamus, BST, and nucleus accumbens. Overall, these data suggest that complex interactions exist between brain reward and stress pathways and that palatable snacking can

Caught in-between: System for in-flow inactivation of enzymes as an intermediary step in “plug-and-play” microfluidic platforms

DEFF Research Database (Denmark)

Fernandes, Ana C.; Petersen, Benjamin; Møller, Lars

2018-01-01

for rapidenzyme inactivation. The thermal inactivation platform developed is compared with a standard benchtop ThermoMixer in terms of inactivation efficiency for glucose oxidase and catalase. A higher activity loss was observed for enzyme inactivation under flow conditions (inactivation achieved at 120 s...

Dynamic gene and protein expression patterns of the autism-associated met receptor tyrosine kinase in the developing mouse forebrain.

Science.gov (United States)

Judson, Matthew C; Bergman, Mica Y; Campbell, Daniel B; Eagleson, Kathie L; Levitt, Pat

2009-04-10

The establishment of appropriate neural circuitry depends on the coordination of multiple developmental events across space and time. These events include proliferation, migration, differentiation, and survival-all of which can be mediated by hepatocyte growth factor (HGF) signaling through the Met receptor tyrosine kinase. We previously found a functional promoter variant of the MET gene to be associated with autism spectrum disorder, suggesting that forebrain circuits governing social and emotional function may be especially vulnerable to developmental disruptions in HGF/Met signaling. However, little is known about the spatiotemporal distribution of Met expression in the forebrain during the development of such circuits. To advance our understanding of the neurodevelopmental influences of Met activation, we employed complementary Western blotting, in situ hybridization, and immunohistochemistry to comprehensively map Met transcript and protein expression throughout perinatal and postnatal development of the mouse forebrain. Our studies reveal complex and dynamic spatiotemporal patterns of expression during this period. Spatially, Met transcript is localized primarily to specific populations of projection neurons within the neocortex and in structures of the limbic system, including the amygdala, hippocampus, and septum. Met protein appears to be principally located in axon tracts. Temporally, peak expression of transcript and protein occurs during the second postnatal week. This period is characterized by extensive neurite outgrowth and synaptogenesis, supporting a role for the receptor in these processes. Collectively, these data suggest that Met signaling may be necessary for the appropriate wiring of forebrain circuits, with particular relevance to the social and emotional dimensions of behavior. (c) 2009 Wiley-Liss, Inc.

Forebrain-specific knockout of B-raf kinase leads to deficits in hippocampal long-term potentiation, learning, and memory.

Science.gov (United States)

Chen, Adele P; Ohno, Masuo; Giese, K Peter; Kühn, Ralf; Chen, Rachel L; Silva, Alcino J

2006-01-01

Raf kinases are downstream effectors of Ras and upstream activators of the MEK-ERK cascade. Ras and MEK-ERK signaling play roles in learning and memory (L&M) and neural plasticity, but the roles of Raf kinases in L&M and plasticity are unclear. Among Raf isoforms, B-raf is preferentially expressed in the brain. To determine whether B-raf has a role in synaptic plasticity and L&M, we used the Cre-LoxP gene targeting system to derive forebrain excitatory neuron B-raf knockout mice. This conditional knockout resulted in deficits in ERK activation and hippocampal long-term potentiation (LTP) and impairments in hippocampus-dependent L&M, including spatial learning and contextual discrimination. Despite the widespread expression of B-raf, this mutation did not disrupt other forms of L&M, such as cued fear conditioning and conditioned taste aversion. Our findings demonstrate that B-raf plays a role in hippocampal ERK activation, synaptic plasticity, and L&M.

Impaired hair follicle morphogenesis and polarized keratinocyte movement upon conditional inactivation of integrin-linked kinase in the epidermis.

Science.gov (United States)

Nakrieko, Kerry-Ann; Welch, Ian; Dupuis, Holly; Bryce, Dawn; Pajak, Agnieszka; St Arnaud, René; Dedhar, Shoukat; D'Souza, Sudhir J A; Dagnino, Lina

2008-04-01

Integrin-linked kinase (ILK) is key for cell survival, migration, and adhesion, but little is known about its role in epidermal development and homeostasis in vivo. We generated mice with conditional inactivation of the Ilk gene in squamous epithelia. These mice die perinatally and exhibit skin blistering and severe defects in hair follicle morphogenesis, including greatly reduced follicle numbers, failure to progress beyond very early developmental stages, and pronounced defects in follicular keratinocyte proliferation. ILK-deficient epidermis shows abnormalities in adhesion to the basement membrane and in differentiation. ILK-deficient cultured keratinocytes fail to attach and spread efficiently and exhibit multiple abnormalities in actin cytoskeletal organization. Ilk gene inactivation in cultured keratinocytes causes impaired ability to form stable lamellipodia, to directionally migrate, and to polarize. These defects are accompanied by abnormal distribution of active Cdc42 to cell protrusions, as well as reduced activation of Rac1 upon induction of cell migration in scraped keratinocyte monolayers. Significantly, alterations in cell spreading and forward movement in single cells can be rescued by expression of constitutively active Rac1 or RhoG. Our studies underscore a central and distinct role for ILK in hair follicle development and in polarized cell movements, two key aspects of epithelial morphogenesis and function.

Topographic Organization of Cholinergic Innervation From the Basal Forebrain to the Visual Cortex in the Rat

Directory of Open Access Journals (Sweden)

Frédéric Huppé-Gourgues

2018-03-01

Full Text Available Acetylcholine is an important neurotransmitter for the regulation of visual attention, plasticity, and perceptual learning. It is released in the visual cortex predominantly by cholinergic projections from the basal forebrain, where stimulation may produce potentiation of visual processes. However, little is known about the fine organization of these corticopetal projections, such as whether basal forebrain neurons projecting to the primary and secondary visual cortical areas (V1 and V2, respectively are organized retinotopically. The aim of this study was to map these basal forebrain-V1/V2 projections. Microinjections of the fluorescent retrograde tracer cholera toxin b fragment in different sites within V1 and V2 in Long–Evans rats were performed. Retrogradely labeled cell bodies in the horizontal and vertical limbs of the diagonal band of Broca (HDB and VDB, respectively, nucleus basalis magnocellularis, and substantia innominata (SI, were mapped ex vivo with a computer-assisted microscope stage controlled by stereological software. Choline acetyltranferase immunohistochemistry was used to identify cholinergic cells. Our results showed a predominance of cholinergic projections coming from the HDB. These projections were not retinotopically organized but projections to V1 arised from neurons located in the anterior HDB/SI whereas projections to V2 arised from neurons located throughout the whole extent of HDB/SI. The absence of a clear topography of these projections suggests that BF activation can stimulate visual cortices broadly.

Neuropeptide Y in the forebrain of the adult male cichlid fish Oreochromis mossambicus: distribution, effects of castration and testosterone replacement.

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Sakharkar, Amul J; Singru, Praful S; Sarkar, Koustav; Subhedar, Nishikant K

2005-08-22

We studied the organization of the neuropeptide Y (NPY)-immunoreactive system in the forebrain of adult male cichlid fish Oreochromis mossambicus and its response to castration and testosterone replacement by using morphometric methods. Immunoreactivity for NPY was widely distributed in the forebrain, and the pattern generally resembled that in other teleosts. Whereas immunoreactivity was conspicuous in the ganglia of nervus terminalis (NT; or nucleus olfactoretinalis), a weak reaction was detected in some granule cells in the olfactory bulb and in the cells of area ventralis telencephali pars lateralis (Vl). Moderately to intensely immunoreactive cells were distinctly seen in the nucleus entopeduncularis (NE), nucleus preopticus (NPO), nucleus lateralis tuberis (NLT), paraventricular organ (PVO), and midbrain tegmentum (MT). NPY fibers were widely distributed in the forebrain. Castration for 10/15 days resulted in a drastic loss of immunoreactivity in the cells of NE (P<0.001) and a significant decrease (P<0.01) in their cell nuclear size. However, cell nuclei of the NT neurons showed a significant increase in size. A highly significant reduction in the NPY-immunoreactive fiber density (P<0.001) was observed in several areas of the forebrain. Although testosterone replacement reversed these changes, fibers in some areas showed supranormal responses. Immunoreactive cells in Vl, NPO, NLT, PVO, and MT and fiber density in some other areas did not respond to castration. We suggest that the NPY-immunoreactive elements that respond to castration and testosterone replacement may serve as the substrate for processing the positive feedback action of the steroid hormone. (c) 2005 Wiley-Liss, Inc.

Radical inactivation of a biological sulphydryl molecule

International Nuclear Information System (INIS)

Lin, W.S.; Lal, M.; Gaucher, G.M.; Armstrong, D.A.

1977-01-01

Reactive species produced from the free radical-induced chain oxidation of low molecular weight sulphydryl-containing molecules in aerated solutions deactivate the sulphydryl-containing enzyme papain, forming both reparable mixed disulphides and non-reparable products. This inactivation is highly efficient for penicillamine and glutathione, but almost negligible with cysteine, which is a protector of papain for [cysteine] / [papain] >= 5 under all conditions used. In the case of glutathione, superoxide dismutase caused only a small reduction in the inactivation and peroxide yields were small, implying that the deactivating species are not .O 2 - but RSOO. radicals or products from them. For penicillamine, however, dimutase was highly effective and the peroxide yields were relatively large, demonstrating that .O 2 - or a radical with similar capabilities for forming H 2 O 2 and being deactivated by dismutase was involved. Although in the presence of dismutase penicillamine is a better protector of non-reparable papain inactivation than glutathione, it suffers from a deficiency in that the papain-penicillamine mixed disulphide, which is always formed, cannot be repaired by spontaneous reaction with RSH molecules. (author)

Increases in extracellular serotonin and dopamine metabolite levels in the basal forebrain during sleep deprivation

NARCIS (Netherlands)

Zant, J.C.; Leenaars, C.H.; Kostin, A.; van Someren, E.J.W.; Porrka-Heiskanen, T.

2011-01-01

The basal forebrain (BF) is an important mediator of cortical arousal, which is innervated by all ascending arousal systems. During sleep deprivation (SD) a site-specific accumulation of sleep factors in the BF results in increased sleep pressure (Kalinchuk et al., 2006; Porkka-Heiskanen et al.,

Selective immunotoxic lesions of basal forebrain cholinergic cells: effects on learning and memory in rats.

Science.gov (United States)

Baxter, Mark G; Bucci, David J; Gorman, Linda K; Wiley, Ronald G; Gallagher, Michela

2013-10-01

Male Long-Evans rats were given injections of either 192 IgG-saporin, an apparently selective toxin for basal forebrain cholinergic neurons (LES), or vehicle (CON) into either the medial septum and vertical limb of the diagonal band (MS/VDB) or bilaterally into the nucleus basalis magnocellularis and substantia innominata (nBM/SI). Place discrimination in the Morris water maze assessed spatial learning, and a trial-unique matching-to-place task in the water maze assessed memory for place information over varying delays. MS/VDB-LES and nBM/SI-LES rats were not impaired relative to CON rats in acquisition of the place discrimination, but were mildly impaired relative to CON rats in performance of the memory task even at the shortest delay, suggesting a nonmnemonic deficit. These results contrast with effects of less selective lesions, which have been taken to support a role for basal forebrain cholinergic neurons in learning and memory. 2013 APA, all rights reserved

Predicting Bacillus coagulans spores inactivation in tomato pulp under nonisothermal heat treatments.

Science.gov (United States)

Zimmermann, Morgana; Longhi, Daniel A; Schaffner, Donald W; Aragão, Gláucia M F

2014-05-01

The knowledge and understanding of Bacillus coagulans inactivation during a thermal treatment in tomato pulp, as well as the influence of temperature variation during thermal processes are essential for design, calculation, and optimization of the process. The aims of this work were to predict B. coagulans spores inactivation in tomato pulp under varying time-temperature profiles with Gompertz-inspired inactivation model and to validate the model's predictions by comparing the predicted values with experimental data. B. coagulans spores in pH 4.3 tomato pulp at 4 °Brix were sealed in capillary glass tubes and heated in thermostatically controlled circulating oil baths. Seven different nonisothermal profiles in the range from 95 to 105 °C were studied. Predicted inactivation kinetics showed similar behavior to experimentally observed inactivation curves when the samples were exposed to temperatures in the upper range of this study (99 to 105 °C). Profiles that resulted in less accurate predictions were those where the range of temperatures analyzed were comparatively lower (inactivation profiles starting at 95 °C). The link between fail prediction and both lower starting temperature and magnitude of the temperature shift suggests some chemical or biological mechanism at work. Statistical analysis showed that overall model predictions were acceptable, with bias factors from 0.781 to 1.012, and accuracy factors from 1.049 to 1.351, and confirm that the models used were adequate to estimate B. coagulans spores inactivation under fluctuating temperature conditions in the range from 95 to 105 °C. How can we estimate Bacillus coagulans inactivation during sudden temperature shifts in heat processing? This article provides a validated model that can be used to predict B. coagulans under changing temperature conditions. B. coagulans is a spore-forming bacillus that spoils acidified food products. The mathematical model developed here can be used to predict the spoilage

Neuroregulatory and neuroendocrine GnRH pathways in the hypothalamus and forebrain of the baboon.

Science.gov (United States)

Marshall, P E; Goldsmith, P C

1980-07-14

The distribution of neurons containing gonadotropin-releasing hormone (GnRH) in the baboon hypothalamus and forebrain was studied immunocytochemically by light and electron microscopy. GnRH was present in the perikarya, axonal and dendritic processes of immunoreactive neurons. Three populations of GnRH neurons could be distinguished. Most of the GnRH neurons which are assumed to directly influence the anterior pituitary were in the medial basal hypothalamus. Other cells that projected to the median eminence were found scattered throughout the hypothalamus. A second, larger population of neurons apparently was not involved with control of the anterior pituitary. These neurons were generally found within afferent and efferent pathways of the hypothalamus and forebrain, and may receive external information affecting reproduction. A few neurons projecting to the median eminence were also observed sending collaterals to other brain areas. Thus, in addition to their neuroendocrine role, these cells possibly have neuroregulatory functions. The inference is made that these bifunctional neurons, together with the widely observed GnRH-GnRH cellular interactions may help to synchronize ovulation and sexual behavior.

Carvacrol suppresses high pressure high temperature inactivation of Bacillus cereus spores.

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Luu-Thi, Hue; Corthouts, Jorinde; Passaris, Ioannis; Grauwet, Tara; Aertsen, Abram; Hendrickx, Marc; Michiels, Chris W

2015-03-16

The inactivation of bacterial spores generally proceeds faster and at lower temperatures when heat treatments are conducted under high pressure, and high pressure high temperature (HPHT) processing is, therefore, receiving an increased interest from food processors. However, the mechanisms of spore inactivation by HPHT treatment are poorly understood, particularly at moderately elevated temperature. In the current work, we studied inactivation of the spores of Bacillus cereus F4430/73 by HPHT treatment for 5 min at 600MPa in the temperature range of 50-100°C, using temperature increments of 5°C. Additionally, we investigated the effect of the natural antimicrobial carvacrol on spore germination and inactivation under these conditions. Spore inactivation by HPHT was less than about 1 log unit at 50 to 70°C, but gradually increased at higher temperatures up to about 5 log units at 100°C. DPA release and loss of spore refractility in the spore population were higher at moderate (≤65°C) than at high (≥70°C) treatment temperatures, and we propose that moderate conditions induced the normal physiological pathway of spore germination resulting in fully hydrated spores, while at higher temperatures this pathway was suppressed and replaced by another mechanism of pressure-induced dipicolinic acid (DPA) release that results only in partial spore rehydration, probably because spore cortex hydrolysis is inhibited. Carvacrol strongly suppressed DPA release and spore rehydration during HPHT treatment at ≤65°C and also partly inhibited DPA release at ≥65°C. Concomitantly, HPHT spore inactivation was reduced by carvacrol at 65-90°C but unaffected at 95-100°C. Copyright © 2014 Elsevier B.V. All rights reserved.

Inactivation of murine norovirus by chemical biocides on stainless steel

Science.gov (United States)

2009-01-01

Background Human norovirus (NoV) causes more than 80% of nonbacterial gastroenteritis in Europe and the United States. NoV transmission via contaminated surfaces may be significant for the spread of viruses. Therefore, measures for prevention and control, such as surface disinfection, are necessary to interrupt the dissemination of human NoV. Murine norovirus (MNV) as a surrogate for human NoV was used to study the efficacy of active ingredients of chemical disinfectants for virus inactivation on inanimate surfaces. Methods The inactivating properties of different chemical biocides were tested in a quantitative carrier test with stainless steel discs without mechanical action. Vacuum-dried MNV was exposed to different concentrations of alcohols, peracetic acid (PAA) or glutaraldehyde (GDA) for 5 minutes exposure time. Detection of residual virus was determined by endpoint-titration on RAW 264.7 cells. Results PAA [1000 ppm], GDA [2500 ppm], ethanol [50% (v/v)] and 1-propanol [30% (v/v)] were able to inactivate MNV under clean conditions (0.03% BSA) on the carriers by ≥ 4 log10 within 5 minutes exposure time, whereas 2-propanol showed a reduced effectiveness even at 60% (v/v). Furthermore, there were no significant differences in virus reduction whatever interfering substances were used. When testing with ethanol, 1- and 2-propanol, results under clean conditions were nearly the same as in the presence of dirty conditions (0.3% BSA plus 0.3% erythrocytes). Conclusion Products based upon PAA, GDA, ethanol and 1-propanol should be used for NoV inactivation on inanimate surfaces. Our data provide valuable information for the development of strategies to control NoV transmission via surfaces. PMID:19583832

Inactivation of murine norovirus by chemical biocides on stainless steel

Directory of Open Access Journals (Sweden)

Steinmann Jörg

2009-07-01

Full Text Available Abstract Background Human norovirus (NoV causes more than 80% of nonbacterial gastroenteritis in Europe and the United States. NoV transmission via contaminated surfaces may be significant for the spread of viruses. Therefore, measures for prevention and control, such as surface disinfection, are necessary to interrupt the dissemination of human NoV. Murine norovirus (MNV as a surrogate for human NoV was used to study the efficacy of active ingredients of chemical disinfectants for virus inactivation on inanimate surfaces. Methods The inactivating properties of different chemical biocides were tested in a quantitative carrier test with stainless steel discs without mechanical action. Vacuum-dried MNV was exposed to different concentrations of alcohols, peracetic acid (PAA or glutaraldehyde (GDA for 5 minutes exposure time. Detection of residual virus was determined by endpoint-titration on RAW 264.7 cells. Results PAA [1000 ppm], GDA [2500 ppm], ethanol [50% (v/v] and 1-propanol [30% (v/v] were able to inactivate MNV under clean conditions (0.03% BSA on the carriers by ≥ 4 log10 within 5 minutes exposure time, whereas 2-propanol showed a reduced effectiveness even at 60% (v/v. Furthermore, there were no significant differences in virus reduction whatever interfering substances were used. When testing with ethanol, 1- and 2-propanol, results under clean conditions were nearly the same as in the presence of dirty conditions (0.3% BSA plus 0.3% erythrocytes. Conclusion Products based upon PAA, GDA, ethanol and 1-propanol should be used for NoV inactivation on inanimate surfaces. Our data provide valuable information for the development of strategies to control NoV transmission via surfaces.

Modeling-independent elucidation of inactivation pathways in recombinant and native A-type Kv channels

Science.gov (United States)

Fineberg, Jeffrey D.; Ritter, David M.

2012-01-01

A-type voltage-gated K+ (Kv) channels self-regulate their activity by inactivating directly from the open state (open-state inactivation [OSI]) or by inactivating before they open (closed-state inactivation [CSI]). To determine the inactivation pathways, it is often necessary to apply several pulse protocols, pore blockers, single-channel recording, and kinetic modeling. However, intrinsic hurdles may preclude the standardized application of these methods. Here, we implemented a simple method inspired by earlier studies of Na+ channels to analyze macroscopic inactivation and conclusively deduce the pathways of inactivation of recombinant and native A-type Kv channels. We investigated two distinct A-type Kv channels expressed heterologously (Kv3.4 and Kv4.2 with accessory subunits) and their native counterparts in dorsal root ganglion and cerebellar granule neurons. This approach applies two conventional pulse protocols to examine inactivation induced by (a) a simple step (single-pulse inactivation) and (b) a conditioning step (double-pulse inactivation). Consistent with OSI, the rate of Kv3.4 inactivation (i.e., the negative first derivative of double-pulse inactivation) precisely superimposes on the profile of the Kv3.4 current evoked by a single pulse because the channels must open to inactivate. In contrast, the rate of Kv4.2 inactivation is asynchronous, already changing at earlier times relative to the profile of the Kv4.2 current evoked by a single pulse. Thus, Kv4.2 inactivation occurs uncoupled from channel opening, indicating CSI. Furthermore, the inactivation time constant versus voltage relation of Kv3.4 decreases monotonically with depolarization and levels off, whereas that of Kv4.2 exhibits a J-shape profile. We also manipulated the inactivation phenotype by changing the subunit composition and show how CSI and CSI combined with OSI might affect spiking properties in a full computational model of the hippocampal CA1 neuron. This work unambiguously

Basal forebrain projections to the lateral habenula modulate aggression reward.

Science.gov (United States)

Golden, Sam A; Heshmati, Mitra; Flanigan, Meghan; Christoffel, Daniel J; Guise, Kevin; Pfau, Madeline L; Aleyasin, Hossein; Menard, Caroline; Zhang, Hongxing; Hodes, Georgia E; Bregman, Dana; Khibnik, Lena; Tai, Jonathan; Rebusi, Nicole; Krawitz, Brian; Chaudhury, Dipesh; Walsh, Jessica J; Han, Ming-Hu; Shapiro, Matt L; Russo, Scott J

2016-06-30

Maladaptive aggressive behaviour is associated with a number of neuropsychiatric disorders and is thought to result partly from the inappropriate activation of brain reward systems in response to aggressive or violent social stimuli. Nuclei within the ventromedial hypothalamus, extended amygdala and limbic circuits are known to encode initiation of aggression; however, little is known about the neural mechanisms that directly modulate the motivational component of aggressive behaviour. Here we established a mouse model to measure the valence of aggressive inter-male social interaction with a smaller subordinate intruder as reinforcement for the development of conditioned place preference (CPP). Aggressors develop a CPP, whereas non-aggressors develop a conditioned place aversion to the intruder-paired context. Furthermore, we identify a functional GABAergic projection from the basal forebrain (BF) to the lateral habenula (lHb) that bi-directionally controls the valence of aggressive interactions. Circuit-specific silencing of GABAergic BF-lHb terminals of aggressors with halorhodopsin (NpHR3.0) increases lHb neuronal firing and abolishes CPP to the intruder-paired context. Activation of GABAergic BF-lHb terminals of non-aggressors with channelrhodopsin (ChR2) decreases lHb neuronal firing and promotes CPP to the intruder-paired context. Finally, we show that altering inhibitory transmission at BF-lHb terminals does not control the initiation of aggressive behaviour. These results demonstrate that the BF-lHb circuit has a critical role in regulating the valence of inter-male aggressive behaviour and provide novel mechanistic insight into the neural circuits modulating aggression reward processing.

Regional glucose utilization and blood flow following graded forebrain ischemia in the rat: correlation with neuropathology

International Nuclear Information System (INIS)

Ginsberg, M.D.; Graham, D.I.; Busto, R.

1985-01-01

Regional patterns of cerebral glucose utilization (rCMRglc) and blood flow (rCBF) were examined in the early recovery period following transient forebrain ischemia in order to correlate early postischemic physiological events with regionally selective patterns of ischemic neuropathology. Wistar rats were subjected to 30 or 60 minutes of graded forebrain ischemia by a method combining unilateral occlusion of the common carotid artery with moderate elevation of intracranial pressure and mild hypotension; this procedure results in a high-grade ischemic deficit affecting chiefly the lateral neocortex, striatum, and hippocampus ipsilateral to the carotid occlusion. Simultaneous measurements of rCMRglc and rCBF made in regional tissue samples after 2 and 4 hours of postischemic recirculation using a double-tracer radioisotopic strategy revealed a disproportionately high level of glucose metabolism relative to blood flow in the early postischemic striatum, owing to the resumption of nearly normal rCMRglc in the face of depressed flow. In contrast, the neocortex, which had been equally ischemic, showed parallel depressions of both metabolism and blood flow during early recovery. Light microscopy at 4 and 8 hours after recovery revealed the striatum to be the predominant locus of ischemic neuronal alterations, whereas neocortical lesions were much less prominent in extent and severity at this time. The resumption of normal levels of metabolism in the setting of a disproportionate depression of rCBF in the early postischemic period may accentuate the process of neuronal injury initiated by ischemia and may contribute to the genesis of neuronal necrosis in selectively vulnerable areas of the forebrain

Inactivation of Bacillus spores inoculated in milk by Ultra High Pressure Homogenization.

Science.gov (United States)

Amador Espejo, Genaro Gustavo; Hernández-Herrero, M M; Juan, B; Trujillo, A J

2014-12-01

Ultra High-Pressure Homogenization treatments at 300 MPa with inlet temperatures (Ti) of 55, 65, 75 and 85 °C were applied to commercial Ultra High Temperature treated whole milk inoculated with Bacillus cereus, Bacillus licheniformis, Bacillus sporothermodurans, Bacillus coagulans, Geobacillus stearothermophilus and Bacillus subtilis spores in order to evaluate the inactivation level achieved. Ultra High-Pressure Homogenization conditions at 300 MPa with Ti = 75 and 85 °C were capable of a spore inactivation of ∼5 log CFU/mL. Furthermore, under these processing conditions, commercial sterility (evaluated as the complete inactivation of the inoculated spores) was obtained in milk, with the exception of G. stearothermophilus and B. subtilis treated at 300 MPa with Ti = 75 °C. The results showed that G. stearothermophilus and B. subtilis have higher resistance to the Ultra High-Pressure Homogenization treatments applied than the other microorganisms inoculated and that a treatment performed at 300 MPa with Ti = 85 °C was necessary to completely inactivate these microorganisms at the spore level inoculated (∼1 × 10(6) CFU/mL). Besides, a change in the resistance of B. licheniformis, B. sporothermodurans, G. stearothermophilus and B. subtilis spores was observed as the inactivation obtained increased remarkably in treatments performed with Ti between 65 and 75 °C. This study provides important evidence of the suitability of UHPH technology for the inactivation of spores in high numbers, leading to the possibility of obtaining commercially sterile milk. Copyright © 2014 Elsevier Ltd. All rights reserved.

Lack of cross-tolerance between haloperidol and clozapine towards Fos-protein induction in rat forebrain regions

NARCIS (Netherlands)

Sebens, JB; Koch, T; Korf, J

1996-01-01

We investigated whether the acute effects of haloperidol and clozapine on Fos expression in the rat forebrain are mediated by the same receptors through evaluation of cross-tolerance, particularly in the commonly affected areas. Acutely administered haloperidol (1 mg/kg, i.p.) and clozapine (20

The effect of high mesencephalic transection (cerveau isolé) and pentobarbital on basal forebrain mechanisms of EEG synchronization.

Science.gov (United States)

Obál, F; Benedek, G; Szikszay, M; Obál, F

1979-01-01

A study was made of the effects of high mesencephalic transection (cerveau isolé) and low doses of pentobarbital on the cortical synchronizations elicited in acute immobilized cats by (a) low frequency stimulation of the lateral hypothalamus (HL) and nucleus ventralis anterior thalami (VA) and (b) by low and high frequency stimulation of the laterobasal preoptic region (RPO) and olfactory tubercle (TbOf). The results obtained were as follows: (1) The synchronizations induced by basal forebrain stimulations were found to survive in acute cerveau isolé cats, moreover, even a facilitation of the synchronizing effect were observed. (2) A gradual facilitation was observed upon TbOf and RPO stimulation, while in the case of VA and HL stimulations, the facilitation appeared immediately after the transection. (3) Low doses of pentobarbital depressed the cortical effects of TbOf stimulation, while an increase of the synchronizing effect of low frequency VA and HL stimulation was found. The observations suggested that (i) the synchronizing mechanism in the ventral part of the basal forebrain (RPO and TbOf) differs from that of the thalamus and HL; (ii) the basal forebrain synchronizing mechanism is effective without the contribution of the brain stem; (iii) the mechanism responsible for the synchronizing effect of low frequency HL stimulation is similar as that described for the thalamus.

Effect of extrusion conditions and lipoxygenase inactivation treatment on the physical and nutritional properties of corn/cowpea (Vigna unguiculata) blends.

Science.gov (United States)

Sosa-Moguel, Odri; Ruiz-Ruiz, Jorge; Martínez-Ayala, Alma; González, Rolando; Drago, Silvina; Betancur-Ancona, David; Chel-Guerrero, Luis

2009-01-01

The influence of lipoxygenase inactivation and extrusion cooking on the physical and nutritional properties of corn/cowpea (Vigna unguiculata) blends was studied. Corn was blended in an 80:15 proportion with cowpea flour treated to inactivate lipoxygenase (CI) or non-inactivated cowpea flour (CNI). Extrusion variables were temperature (150 degrees C, 165 degrees C and 180 degrees C) and moisture (15%, 17% and 19%). Based on their physical properties, the 165 degrees C/15% corn:CNI, and 165 degrees C/15% corn:CI, and 150 degrees C/15% corn:CI blends were chosen for nutritional quality analysis. Extrudate chemical composition indicated high crude protein levels compared with standard corn-based products. With the exception of lysine, essential amino acids content in the three treatments met FAO requirements. Extrusion and lipoxygenase inactivation are promising options for developing corn/cowpea extruded snack products with good physical properties and nutritional quality.

Drying characteristic, enzyme inactivation and browning pigmentation kinetics of controlled humidity-convective drying of banana slices

Science.gov (United States)

Sarpong, Frederick; Yu, Xiaojie; Zhou, Cunshan; Oteng-Darko, Patricia; Amenorfe, Leticia Peace; Wu, Bengang; Bai, Junwen; Ma, Haile

2018-04-01

Investigating the kinetics of enzyme activities and browning indexes in food are very essential in understanding the enzyme inactivation and browning pigmentation reaction during drying processing. In order to understand and predict accurately the enzyme inactivation and browning pigmentation of banana slices using Relative Humidity (RH)-convective hot air dryer aided by ultrasound (US) pretreatment, this study was conducted. Drying was carried out with 20 kHz frequency of US-pretreatment using three durations (10 20 and 30 min) and RH (10 20 and 30%) conditions at 70 °C and 2.0 m/s air velocity. The kinetic study of both enzyme inactivation and browning pigmentation results were compared to their relevance of fit in terms of coefficient of correlation (R2), the root mean square error (RMSE) and the reduced chi-square (χ 2). First order and second-order polynomial kinetic model fitted well for enzyme inactivation and browning indexes respectively. Both enzymes inactivation kinetics and enzymatic browning index (EBI) declined significantly (p drying time in all drying conditions and rate of decrease intensified in longer US-pretreatment duration and lower RH conditions. However, shorter US-pretreatment duration and higher RH conditions reduced the non- enzymatic browning index (NBI) significantly. Again, longer US-pretreatment duration and lower RH shortened the drying time but adversely created more microspores from the micrograph study. Longer US pretreatment and lower RH decrease significantly (p < 0.05) the L* and b* values whereas the a* values was increased.

Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

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Takashi Furukawa

2017-07-01

Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.

Reversible Heat-Induced Inactivation of Chimeric β-Glucuronidase in Transgenic Plants1

Science.gov (United States)

Almoguera, Concepción; Rojas, Anabel; Jordano, Juan

2002-01-01

We compared the expression patterns in transgenic tobacco (Nicotiana tabacum) of two chimeric genes: a translational fusion to β-glucuronidase (GUS) and a transcriptional fusion, both with the same promoter and 5′-flanking sequences of Ha hsp17.7 G4, a small heat shock protein (sHSP) gene from sunflower (Helianthus annuus). We found that immediately after heat shock, the induced expression from the two fusions in seedlings was similar, considering chimeric mRNA or GUS protein accumulation. Surprisingly, we discovered that the chimeric GUS protein encoded by the translational fusion was mostly inactive in such conditions. We also found that this inactivation was fully reversible. Thus, after returning to control temperature, the GUS activity was fully recovered without substantial changes in GUS protein accumulation. In contrast, we did not find differences in the in vitro heat inactivation of the respective GUS proteins. Insolubilization of the chimeric GUS protein correlated with its inactivation, as indicated by immunoprecipitation analyses. The inclusion in another chimeric gene of the 21 amino-terminal amino acids from a different sHSP lead to a comparable reversible inactivation. That effect not only illustrates unexpected post-translational problems, but may also point to sequences involved in interactions specific to sHSPs and in vivo heat stress conditions. PMID:12011363

Role of dopant concentration, crystal phase and particle size on microbial inactivation of Cu-doped TiO{sub 2} nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Sahu, Manoranjan; Wu Bing; Zhu Liying; Jacobson, Craig; Wang Weining; Jones, Kristen; Goyal, Yogesh; Tang, Yinjie J; Biswas, Pratim, E-mail: pbiswas@wustl.edu [Department of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, MO 63130 (United States)

2011-10-14

The properties of Cu-doped TiO{sub 2} nanoparticles (NPs) were independently controlled in a flame aerosol reactor by varying the molar feed ratios of the precursors, and by optimizing temperature and time history in the flame. The effect of the physico-chemical properties (dopant concentration, crystal phase and particle size) of Cu-doped TiO{sub 2} nanoparticles on inactivation of Mycobacterium smegmatis (a model pathogenic bacterium) was investigated under three light conditions (complete dark, fluorescent light and UV light). The survival rate of M. smegmatis (in a minimal salt medium for 2 h) exposed to the NPs varied depending on the light irradiation conditions as well as the dopant concentrations. In dark conditions, pristine TiO{sub 2} showed insignificant microbial inactivation, but inactivation increased with increasing dopant concentration. Under fluorescent light illumination, no significant effect was observed for TiO{sub 2}. However, when TiO{sub 2} was doped with copper, inactivation increased with dopant concentration, reaching more than 90% (>3 wt% dopant). Enhanced microbial inactivation by TiO{sub 2} NPs was observed only under UV light. When TiO{sub 2} NPs were doped with copper, their inactivation potential was promoted and the UV-resistant cells were reduced by over 99%. In addition, the microbial inactivation potential of NPs was also crystal-phase-and size-dependent under all three light conditions. A lower ratio of anatase phase and smaller sizes of Cu-doped TiO{sub 2} NPs resulted in decreased bacterial survival. The increased inactivation potential of doped TiO{sub 2} NPs is possibly due to both enhanced photocatalytic reactions and leached copper ions.

Skewed X-inactivation in cloned mice

International Nuclear Information System (INIS)

Senda, Sho; Wakayama, Teruhiko; Yamazaki, Yukiko; Ohgane, Jun; Hattori, Naka; Tanaka, Satoshi; Yanagimachi, Ryuzo; Shiota, Kunio

2004-01-01

In female mammals, dosage compensation for X-linked genes is accomplished by inactivation of one of two X chromosomes. The X-inactivation ratio (a percentage of the cells with inactivated maternal X chromosomes in the whole cells) is skewed as a consequence of various genetic mutations, and has been observed in a number of X-linked disorders. We previously reported that phenotypically normal full-term cloned mouse fetuses had loci with inappropriate DNA methylation. Thus, cloned mice are excellent models to study abnormal epigenetic events in mammalian development. In the present study, we analyzed X-inactivation ratios in adult female cloned mice (B6C3F1). Kidneys of eight naturally produced controls and 11 cloned mice were analyzed. Although variations in X-inactivation ratio among the mice were observed in both groups, the distributions were significantly different (Ansary-Bradley test, P < 0.01). In particular, 2 of 11 cloned mice showed skewed X-inactivation ratios (19.2% and 86.8%). Similarly, in intestine, 1 of 10 cloned mice had a skewed ratio (75.7%). Skewed X-inactivation was observed to various degrees in different tissues of different individuals, suggesting that skewed X-inactivation in cloned mice is the result of secondary cell selection in combination with stochastic distortion of primary choice. The present study is the first demonstration that skewed X-inactivation occurs in cloned animals. This finding is important for understanding both nuclear transfer technology and etiology of X-linked disorders

Free radical inactivation of trypsin

International Nuclear Information System (INIS)

Cudina, Ivana; Jovanovic, S.V.

1988-01-01

Reactivities of free radical oxidants, radical OH, Br2-anion radical and Cl 3 COO radical and a reductant, CO2-anion radical, with trypsin and reactive protein components were determined by pulse radiolysis of aqueous solutions at pH 7, 20 0 C. Highly reactive free radicals, radical OH, Br2-anion radical and CO2-anion radical, react with trypsin at diffusion controlled rates. Moderately reactive trichloroperoxy radical, k(Cl 3 COO radical + trypsin) preferentially oxidizes histidine residues. The efficiency of inactivation of trypsin by free radicals is inversely proportional to their reactivity. The yields of inactivation of trypsin by radical OH, Br2-anion radical and CO2-anion radical are low, G(inactivation) = 0.6-0.8, which corresponds to ∼ 10% of the initially produced radicals. In contrast, Cl 3 COO radical inactivates trypsin with ∼ 50% efficiency, i.e. G(inactivation) = 3.2. (author)

Forebrain-Specific Loss of BMPRII in Mice Reduces Anxiety and Increases Object Exploration

OpenAIRE

McBrayer, Zofeyah L.; Dimova, Jiva; Pisansky, Marc T.; Sun, Mu; Beppu, Hideyuki; Gewirtz, Jonathan C.; O’Connor, Michael B.

2015-01-01

To investigate the role of Bone Morphogenic Protein Receptor Type II (BMPRII) in learning, memory, and exploratory behavior in mice, a tissue-specific knockout of BMPRII in the post-natal hippocampus and forebrain was generated. We found that BMPRII mutant mice had normal spatial learning and memory in the Morris water maze, but showed significantly reduced swimming speeds with increased floating behavior. Further analysis using the Porsolt Swim Test to investigate behavioral despair did not ...

Visceral hyperalgesia induced by forebrain-specific suppression of native Kv7/KCNQ/M-current in mice

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Bian Xiling

2011-10-01

Full Text Available Abstract Background Dysfunction of brain-gut interaction is thought to underlie visceral hypersensitivity which causes unexplained abdominal pain syndromes. However, the mechanism by which alteration of brain function in the brain-gut axis influences the perception of visceral pain remains largely elusive. In this study we investigated whether altered brain activity can generate visceral hyperalgesia. Results Using a forebrain specific αCaMKII promoter, we established a line of transgenic (Tg mice expressing a dominant-negative pore mutant of the Kv7.2/KCNQ2 channel which suppresses native KCNQ/M-current and enhances forebrain neuronal excitability. Brain slice recording of hippocampal pyramidal neurons from these Tg mice confirmed the presence of hyperexcitable properties with increased firing. Behavioral evaluation of Tg mice exhibited increased sensitivity to visceral pain induced by intraperitoneal (i.p. injection of either acetic acid or magnesium sulfate, and intracolon capsaicin stimulation, but not cutaneous sensation for thermal or inflammatory pain. Immunohistological staining showed increased c-Fos expression in the somatosensory SII cortex and insular cortex of Tg mice that were injected intraperitoneally with acetic acid. To mimic the effect of cortical hyperexcitability on visceral hyperalgesia, we injected KCNQ/M channel blocker XE991 into the lateral ventricle of wild type (WT mice. Intracerebroventricular injection of XE991 resulted in increased writhes of WT mice induced by acetic acid, and this effect was reversed by co-injection of the channel opener retigabine. Conclusions Our findings provide evidence that forebrain hyperexcitability confers visceral hyperalgesia, and suppression of central hyperexcitability by activation of KCNQ/M-channel function may provide a therapeutic potential for treatment of abdominal pain syndromes.

ABA and ABC renewal of conditioned magazine approach are not impaired by dorsal hippocampus inactivation or lesions

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Campese, Vincent; Delamater, Andrew R.

2013-01-01

Three experiments investigated the role of the dorsal hippocampus (DH) in renewal of conditioned and then extinguished magazine approach responding in rats. Experiments 1 and 2 found no effect of muscimol inactivation of the DH during testing on ABA and ABC renewal, respectively. However, subjects from these studies were subsequently found to be impaired on a delayed non-matching-to-place task following muscimol but not saline infusions. Experiment 3 found no effects of post-training excitotoxic lesions of the DH on ABA and ABC renewal. Lesioned subjects were, however, impaired on the delayed non-matching-to-place task compared to control subjects. These findings suggest that the DH may not play a similar role in Pavlovian extinction in appetitive learning tasks as has previously been reported in aversive learning. PMID:23583520

Effects of short-term hormonal replacement on learning and on basal forebrain ChAT and TrkA content in ovariectomized rats.

Science.gov (United States)

Espinosa-Raya, Judith; Plata-Cruz, Noemí; Neri-Gómez, Teresa; Camacho-Arroyo, Ignacio; Picazo, Ofir

2011-02-23

It has been proposed that sex steroid hormones improve performance in some cognitive tasks by regulating the basal forebrain cholinergic function. However, the molecular basis of such influence still remains unknown. Current study analyzed the performance of ovariectomized rats in an autoshaping learning task after a short-term treatment with 17β-estradiol (E2: 4 and 40μg/kg) and/or progesterone (P4: 4mg/kg). These results were correlated with basal forebrain choline acetyltransferase (ChAT) and TrkA protein content. The high dose of E2 enhanced both acquisition in the autoshaping task and the content of ChAT and TrkA. P4 treatment increased ChAT and TrkA content without affecting performance of rats in the autoshaping learning task. Interestingly, the continuous and simultaneous administration of E2 plus P4 did not significantly modify behavioral and biochemical evaluated parameters. These results address the influence of both E2 and P4 on cholinergic and TrkA activity and suggest that the effects of ovarian hormones on cognitive performance involve basal forebrain cholinergic neurons. Copyright © 2010 Elsevier B.V. All rights reserved.

Long-lasting novelty-induced neuronal reverberation during slow-wave sleep in multiple forebrain areas.

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Sidarta Ribeiro

2004-01-01

Full Text Available The discovery of experience-dependent brain reactivation during both slow-wave (SW and rapid eye-movement (REM sleep led to the notion that the consolidation of recently acquired memory traces requires neural replay during sleep. To date, however, several observations continue to undermine this hypothesis. To address some of these objections, we investigated the effects of a transient novel experience on the long-term evolution of ongoing neuronal activity in the rat forebrain. We observed that spatiotemporal patterns of neuronal ensemble activity originally produced by the tactile exploration of novel objects recurred for up to 48 h in the cerebral cortex, hippocampus, putamen, and thalamus. This novelty-induced recurrence was characterized by low but significant correlations values. Nearly identical results were found for neuronal activity sampled when animals were moving between objects without touching them. In contrast, negligible recurrence was observed for neuronal patterns obtained when animals explored a familiar environment. While the reverberation of past patterns of neuronal activity was strongest during SW sleep, waking was correlated with a decrease of neuronal reverberation. REM sleep showed more variable results across animals. In contrast with data from hippocampal place cells, we found no evidence of time compression or expansion of neuronal reverberation in any of the sampled forebrain areas. Our results indicate that persistent experience-dependent neuronal reverberation is a general property of multiple forebrain structures. It does not consist of an exact replay of previous activity, but instead it defines a mild and consistent bias towards salient neural ensemble firing patterns. These results are compatible with a slow and progressive process of memory consolidation, reflecting novelty-related neuronal ensemble relationships that seem to be context- rather than stimulus-specific. Based on our current and previous results

Targeted electroporation of defined lateral ventricular walls: a novel and rapid method to study fate specification during postnatal forebrain neurogenesis

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Cremer Harold

2011-04-01

Full Text Available Abstract Background Postnatal olfactory bulb (OB neurogenesis involves the generation of granule and periglomerular cells by neural stem cells (NSCs located in the walls of the lateral ventricle (LV. Recent studies show that NSCs located in different regions of the LV give rise to different types of OB neurons. However, the molecular mechanisms governing neuronal specification remain largely unknown and new methods to approach these questions are needed. Results In this study, we refine electroporation of the postnatal forebrain as a technique to perform precise and accurate delivery of transgenes to NSCs located in distinct walls of the LV in the mouse. Using this method, we confirm and expand previous studies showing that NSCs in distinct walls of the LV produce neurons that invade different layers of the OB. Fate mapping of the progeny of radial glial cells located in these distinct LV walls reveals their specification into defined subtypes of granule and periglomerular neurons. Conclusions Our results provide a baseline with which future studies aiming at investigating the role of factors in postnatal forebrain neuronal specification can be compared. Targeted electroporation of defined LV NSC populations will prove valuable to study the genetic factors involved in forebrain neuronal specification.

A specific inactivator of mammalian C'4 isolated from nurse shark (Ginglymostoma cirratum) serum.

Science.gov (United States)

Jensen, J A

1969-08-01

A material which specifically inactivates mammalian C'4 was isolated from low ionic strength precipitates of nurse shark serum. The C'4 inactivator was not detected in whole serum. The conditions of its generation and its immunoelectrophoretic behavior seem to indicate that it is an enzymatically formed cleavage product of a precursor contained in whole shark serum. The inactivator was partially purified and characterized. It had an S-value of 3.3 (sucrose gradient) which was in agreement with its retardation on gel filtration, was stable between pH 5.0 and 10.0, had a half-life of 5 min at 56 degrees C, pH 7.5, was inactivated by trypsin and was nontoxic. Its powerful anticomplementary activity in vitro and in vivo was solely due to the rapid inactivation of C'4; no other complement components were affected. No cofactor requirement was observed for the equally rapid inactivation of highly purified human and guinea pig C'4. The kinetics of C'4 inactivation and TAME hydrolysis, the greater anodic mobility of inactivated human C'4, and the influence of temperature on the rate of inactivation suggest that the inactivator is an enzyme and C'4 its substrate. This conclusion was supported by the more recent detection of a split product of C'4. Intravenous administration of the C'4 inactivator could prevent lethal Forssman shock and suppress the Arthus reaction in guinea pigs; it prolonged significantly the rejection time of renal xenografts but had no detectable effect on passive cutaneous anaphylaxis. Anaphylatoxin could be generated in C'4 depleted guinea pig serum with the cobra venom factor, but not with immune precipitates. The possible relationship between C'1 esterase and the C'4 inactivator is discussed on the basis of similarities and dissimilarities.

Numerical evaluation of lactoperoxidase inactivation during continuous pulsed electric field processing.

Science.gov (United States)

Buckow, Roman; Semrau, Julius; Sui, Qian; Wan, Jason; Knoerzer, Kai

2012-01-01

A computational fluid dynamics (CFD) model describing the flow, electric field and temperature distribution of a laboratory-scale pulsed electric field (PEF) treatment chamber with co-field electrode configuration was developed. The predicted temperature increase was validated by means of integral temperature studies using thermocouples at the outlet of each flow cell for grape juice and salt solutions. Simulations of PEF treatments revealed intensity peaks of the electric field and laminar flow conditions in the treatment chamber causing local temperature hot spots near the chamber walls. Furthermore, thermal inactivation kinetics of lactoperoxidase (LPO) dissolved in simulated milk ultrafiltrate were determined with a glass capillary method at temperatures ranging from 65 to 80 °C. Temperature dependence of first order inactivation rate constants was accurately described by the Arrhenius equation yielding an activation energy of 597.1 kJ mol(-1). The thermal impact of different PEF processes on LPO activity was estimated by coupling the derived Arrhenius model with the CFD model and the predicted enzyme inactivation was compared to experimental measurements. Results indicated that LPO inactivation during combined PEF/thermal treatments was largely due to thermal effects, but 5-12% enzyme inactivation may be related to other electro-chemical effects occurring during PEF treatments. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

Distinct roles of basal forebrain cholinergic neurons in spatial and object recognition memory

OpenAIRE

Kana Okada; Kayo Nishizawa; Tomoko Kobayashi; Shogo Sakata; Kazuto Kobayashi

2015-01-01

Recognition memory requires processing of various types of information such as objects and locations. Impairment in recognition memory is a prominent feature of amnesia and a symptom of Alzheimer?s disease (AD). Basal forebrain cholinergic neurons contain two major groups, one localized in the medial septum (MS)/vertical diagonal band of Broca (vDB), and the other in the nucleus basalis magnocellularis (NBM). The roles of these cell groups in recognition memory have been debated, and it remai...

Pasteurization of milk: the heat inactivation kinetics of milk-borne dairy pathogens under commercial-type conditions of turbulent flow.

Science.gov (United States)

Pearce, L E; Smythe, B W; Crawford, R A; Oakley, E; Hathaway, S C; Shepherd, J M

2012-01-01

This is the first study to report kinetic data on the survival of a range of significant milk-borne pathogens under commercial-type pasteurization conditions. The most heat-resistant strain of each of the milk-borne pathogens Staphylococcus aureus, Yersinia enterocolitica, pathogenic Escherichia coli, Cronobacter sakazakii (formerly known as Enterobacter sakazakii), Listeria monocytogenes, and Salmonella was selected to obtain the worst-case scenario in heat inactivation trials using a pilot-plant-scale pasteurizer. Initially, approximately 30 of each species were screened using a submerged coil unit. Then, UHT milk was inoculated with the most heat-resistant pathogens at ~10(7)/mL and heat treated in a pilot-plant-scale pasteurizer under commercial-type conditions of turbulent flow for 15s over a temperature range from 56 to 66°C and at 72°C. Survivors were enumerated on nonselective media chosen for the highest efficiency of plating of heat-damaged bacteria of each of the chosen strains. The mean log(10) reductions and temperatures of inactivation of the 6 pathogens during a 15-s treatment were Staph. aureus >6.7 at 66.5°C, Y. enterocolitica >6.8 at 62.5°C, pathogenic E. coli >6.8 at 65°C, C. sakazakii >6.7 at 67.5°C, L. monocytogenes >6.9 at 65.5°C, and Salmonella ser. Typhimurium >6.9 at 61.5°C. The kinetic data from these experiments will be used by the New Zealand Ministry of Agriculture and Forestry to populate the quantitative risk assessment model being developed to investigate the risks to New Zealand consumers from pasteurized, compared with nonpasteurized, milk and milk products. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Long-term effects of cholinergic basal forebrain lesions on neuropeptide Y and somatostatin immunoreactivity in rat neocortex

NARCIS (Netherlands)

Gaykema, R.P.A.; Compaan, J.C.; Nyakas, C.; Horvath, E.; Luiten, P.G.M.

1989-01-01

The effect of cholinergic basal forebrain lesions on immunoreactivity to somatostatin (SOM-i) and neuropeptide-Y (NPY-i) was investigated in the rat parietal cortex, 16-18 months after multiple bilateral ibotenic acid injections in the nucleus basalis complex. As a result of the lesion, the

Radiobiological inactivation of Epstein-Barr virus

International Nuclear Information System (INIS)

Henderson, E.; Heston, L.; Grogan, E.; Miller, G.

1978-01-01

Lymphocyte transforming properties of B95-8 strain Epstein-Barr virus (EBV) are very sensitive to inactivation by either uv or x irradiation. No dose of irradiation increases the transforming capacity of EBV. The x-ray dose needed for inactivation of EBV transformation (dose that results in 37% survival, 60,000 rads) is similar to the dose required for inactivation of plaque formation by herpes simplex virus type 1 (Fischer strain). Although herpes simplex virus is more sensitive than EBV to uv irradiation, this difference is most likely due to differences in the kinetics or mechanisms of repair of uv damage to the two viruses. The results lead to the hypothesis that a large part, or perhaps all, of the EBV genome is in some way needed to initiate transformation. The abilities of EBV to stimulate host cell DNA synthesis, to induce nuclear antigen, and to immortalize are inactivated in parallel. All clones of marmoset cells transformed by irradiated virus produce extracellular transforming virus. These findings suggest that the abilities of the virus to transform and to replicate complete progeny are inactivated together. The amounts of uv and x irradiation that inactivate transformation by B95-8 virus are less than the dose needed to inactivate early antigen induction by the nontransforming P 3 HR-1 strain of EBV. Based on radiobiological inactivation, 10 to 50% of the genome is needed for early antigen induction

Inducible forebrain-specific ablation of the transcription factor Creb during adulthood induces anxiety but no spatial/contextual learning deficits

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Miriam Annika Vogt

2014-11-01

Full Text Available The cyclic AMP (cAMP-response element binding protein (CREB is an activity-dependent transcription factor playing a role in synaptic plasticity, learning and memory, and emotional behavior. However, the impact of Creb ablation on rodent behavior is vague as e.g. memory performance of different Creb mutant mice depends on the specific type of mutation per se but additionally on the background and learning protocol differences. Here we present the first targeted ablation of CREB induced during adulthood selectively in principal forebrain neurons in a pure background strain of C57BL/6 mice. All hippocampal principal neurons exhibited lack of CREB expression. Mutant mice showed a severe anxiety phenotype in the openfield and novel object exploration test as well as in the Dark-Light Box Test, but unaltered hippocampus-dependent long-term memory in the Morris water maze and in context dependent fear conditioning. On the molecular level, CREB ablation led to CREM up regulation in the hippocampus and frontal cortex which may at least in part compensate for the loss of CREB. BDNF, a postulated CREB target gene, was down regulated in the frontal lobe but not in the hippocampus; neurogenesis remained unaltered. Our data indicate that in the adult mouse forebrain the late onset of CREB ablation can, in case of memory functionality, be compensated for and is not essential for memory consolidation and retrieval during adulthood. In contrast, the presence of CREB protein during adulthood seems to be pivotal for the regulation of emotional behavior.

Defects in GPI biosynthesis perturb Cripto signaling during forebrain development in two new mouse models of holoprosencephaly

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David M. McKean

2012-07-01

Holoprosencephaly is the most common forebrain defect in humans. We describe two novel mouse mutants that display a holoprosencephaly-like phenotype. Both mutations disrupt genes in the glycerophosphatidyl inositol (GPI biosynthesis pathway: gonzo disrupts Pign and beaker disrupts Pgap1. GPI anchors normally target and anchor a diverse group of proteins to lipid raft domains. Mechanistically we show that GPI anchored proteins are mislocalized in GPI biosynthesis mutants. Disruption of the GPI-anchored protein Cripto (mouse and TDGF1 (human ortholog have been shown to result in holoprosencephaly, leading to our hypothesis that Cripto is the key GPI anchored protein whose altered function results in an HPE-like phenotype. Cripto is an obligate Nodal co-factor involved in TGFβ signaling, and we show that TGFβ signaling is reduced both in vitro and in vivo. This work demonstrates the importance of the GPI anchor in normal forebrain development and suggests that GPI biosynthesis genes should be screened for association with human holoprosencephaly.

Effects of inactivating individual cerebellar nuclei on the performance and retention of an operantly conditioned forelimb movement.

Science.gov (United States)

Milak, M S; Shimansky, Y; Bracha, V; Bloedel, J R

1997-08-01

These experiments were designed to examine the effects of inactivating separately each of the major cerebellar nuclear regions in cats on the execution and retention of a previously learned, operantly conditioned volitional forelimb movement. The experiments test the postulates that the cerebellar nuclei, and particularly the interposed nuclei, contribute substantially to the spatial and temporal features of the interjoint coordination required to execute the task and that the engram necessary for the retention of this task is not located in any one of the cerebellar nuclei. All cats were trained to perform a task in which they were required to reach for and grasp a vertical bar at the sound of a tone and move the bar to a reward zone through a template consisting of two straight grooves in the shape of an inverted "L." After the task was learned, the effects of inactivating separately each nuclear region (the fastigial, interposed, and dentate nuclei) using muscimol microinjections were determined. Data were analyzed by quantifying several features of the movement's kinematics and by determining changes in the organization of the reaching component of the movement using an application of dimensionality analysis, an analysis that examines the correlation among the changes in joint angles and limb segment positions during the task. The retention of the previously learned task also was assessed after each injection. Injections of each nuclear region affected temporal and spatial features of the learned movement. However, the largest effects resulted from inactivating the interposed nuclei. These effects included an increased length of the reach trajectory, an accentuated deviation of the wrist trajectory from a straight line, cyclic movement of the distal extremity as the target was approached, a difficulty in grasping the bar, altered temporal features of the movement, and a highly characteristic change in the dimensionality measurements. The changes in

Neuroprotective effects of ebselen following forebrain ischemia: involvement of glutamate and nitric oxide.

Science.gov (United States)

Koizumi, Hiroyasu; Fujisawa, Hirosuke; Suehiro, Eiichi; Shirao, Satoshi; Suzuki, Michiyasu

2011-01-01

Ebselen is a mimic of glutathione peroxidase that reacts with peroxynitrite and inhibits nitric oxide (NO) synthase. Ebselen has beneficial effects on the neurological outcome of patients with stroke. In this study, the mechanisms by which ebselen can elicit neuroprotective effects against ischemic brain injury were investigated in male Wistar rats. Experimental forebrain ischemia was induced by bilateral common carotid artery occlusion with hemorrhagic hypotension. Ebselen was administered to animals in the treatment group 2 hours prior to the induction of forebrain ischemia, and placebo was administered in the control group. Cerebral blood flow (CBF) was measured by the hydrogen clearance method. Cortical extracellular levels of excitatory amino acids (EAAs) and NO were evaluated using in vivo microdialysis. Neuronal damage in the CA1 subfield of the hippocampus was assessed in brains harvested after a 24-hour period of survival. CBF did not recover to normal physiological levels after ischemic insults in either the control or treatment groups. The differences in the sequential changes in extracellular EAA and NO levels between groups were not statistically significant. There was a significantly larger mean density of intact, undamaged neurons in the CA1 subfield in the treatment group than in the control group. The neuroprotective effects of ebselen were reflected in the histological findings, without significant inhibition of glutamate release or NO synthesis during the acute phase of experimentally induced cerebral ischemia.

Nanoscale Structural and Mechanical Analysis of Bacillus anthracis Spores Inactivated with Rapid Dry Heating

Science.gov (United States)

Felker, Daniel L.; Burggraf, Larry W.

2014-01-01

Effective killing of Bacillus anthracis spores is of paramount importance to antibioterrorism, food safety, environmental protection, and the medical device industry. Thus, a deeper understanding of the mechanisms of spore resistance and inactivation is highly desired for developing new strategies or improving the known methods for spore destruction. Previous studies have shown that spore inactivation mechanisms differ considerably depending upon the killing agents, such as heat (wet heat, dry heat), UV, ionizing radiation, and chemicals. It is believed that wet heat kills spores by inactivating critical enzymes, while dry heat kills spores by damaging their DNA. Many studies have focused on the biochemical aspects of spore inactivation by dry heat; few have investigated structural damages and changes in spore mechanical properties. In this study, we have inactivated Bacillus anthracis spores with rapid dry heating and performed nanoscale topographical and mechanical analysis of inactivated spores using atomic force microscopy (AFM). Our results revealed significant changes in spore morphology and nanomechanical properties after heat inactivation. In addition, we also found that these changes were different under different heating conditions that produced similar inactivation probabilities (high temperature for short exposure time versus low temperature for long exposure time). We attributed the differences to the differential thermal and mechanical stresses in the spore. The buildup of internal thermal and mechanical stresses may become prominent only in ultrafast, high-temperature heat inactivation when the experimental timescale is too short for heat-generated vapor to efficiently escape from the spore. Our results thus provide direct, visual evidences of the importance of thermal stresses and heat and mass transfer to spore inactivation by very rapid dry heating. PMID:24375142

Review: Efficiency of physical and chemical treatments on the inactivation of dairy bacteriophages

Directory of Open Access Journals (Sweden)

Daniela Marta Guglielmotti

2012-01-01

Full Text Available Bacteriophages can cause great economic losses due to fermentation failure in dairy plants. Hence, physical and chemical treatments of raw material and/or equipment are mandatory to maintain phage levels as low as possible. Regarding thermal treatments used to kill pathogenic bacteria or achieve longer shelf-life of dairy products, neither low temperature long time (LTLT nor high temperature short time (HTST pasteurization were able to inactivate most lactic acid bacteria (LAB phages. Even though most phages did not survive 90ºC for 2 min, there were some that resisted 90ºC for more than 15 min (conditions suggested by the International Dairy Federation, IDF, for complete phage destruction. Among biocides tested, ethanol showed variable effectiveness in phage inactivation, since only phages infecting dairy cocci and Lactobacillus helveticus were reasonably inactivated by this alcohol, whereas isopropanol was in all cases highly ineffective. In turn, peracetic acid has consistently proved to be very fast and efficient to inactivate dairy phages, whereas efficiency of sodium hypochlorite was variable, even among different phages infecting the same LAB species. Both alkaline chloride foam and ethoxylated nonylphenol with phosphoric acid were remarkably efficient, trait probably related to their highly alkaline or acidic pH values in solution, respectively. Photocatalysis using UV light and TiO2 has been recently reported as a feasible option to industrially inactivate phages infecting diverse LAB species. Processes involving high pressure were barely used for phage inactivation, but until now most studied phages revealed high resistance to these treatments. To conclude, and given the great phage diversity found on dairies, it is always advisable to combine different anti-phage treatments (biocides, heat, high pressure, photocatalysis, rather than using them separately at extreme conditions.

Chlorine inactivation of Tubifex tubifex in drinking water and the synergistic effect of sequential inactivation with UV irradiation and chlorine.

Science.gov (United States)

Nie, Xiao-Bao; Li, Zhi-Hong; Long, Yuan-Nan; He, Pan-Pan; Xu, Chao

2017-06-01

The inactivation of Tubifex tubifex is important to prevent contamination of drinking water. Chlorine is a widely-used disinfectant and the key factor in the inactivation of T. tubifex. This study investigated the inactivation kinetics of chlorine on T. tubifex and the synergistic effect of the sequential use of chlorine and UV irradiation. The experimental results indicated that the Ct (concentration × time reaction ) concept could be used to evaluate the inactivation kinetics of T. tubifex with chlorine, thus allowing for the use of a simpler Ct approach for the assessment of T. tubifex chlorine inactivation requirements. The inactivation kinetics of T. tubifex by chlorine was found to be well-fitted to a delayed pseudo first-order Chick-Watson expression. Sequential experiments revealed that UV irradiation and chlorine worked synergistically to effectively inactivate T. tubifex as a result of the decreased activation energy, E a , induced by primary UV irradiation. Furthermore, the inactivation effectiveness of T. tubifex by chlorine was found to be affected by several drinking water quality parameters including pH, turbidity, and chemical oxygen demand with potassium permanganate (COD Mn ) concentration. High pH exhibited pronounced inactivation effectiveness and the decrease in turbidity and COD Mn concentrations contributed to the inactivation of T. tubifex. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Coat Layers in Bacillus Subtilis Spores Resistance to Photo-Catalytic Inactivation

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Luz del Carmen Huesca-Espitia

2017-10-01

Full Text Available Different water treatment processes (physical and chemical exist to obtain safe water for human or food industry supply. The advanced oxidation technologies are rising as a new alternative to eliminate undesirable chemicals and waterborne diseases. In this work, we analyze the power of the photo-assisted Fenton process using Fe(II/H2O2 and UV radiation (365 nm to inactivate Bacillus subtilis spores, considered among the most resistant biological structures known. Different concentrations of Fe(II, H2O2 and UV radiation (365 nm were used to inactivate wt and some coat spore mutants of B. subtilis. Wt spores of B. subtilis were inactivated after 60 min using this process. In general, all defective coat mutants were more sensitive than the wt spores and, particularly, the double mutant was 10 folds more sensitive than others being inactivated during the first 10 minutes using soft reaction conditions. Presence of Fe(II ions was found essential for spore inactivating process and, for those spores inactivated using the Fe(II/H2O2 under UV radiation process, it is suggested that coat structures are important to their resistance to the treatment process. The photo-assisted Fenton process using Fe(II, H2O2 and UV radiation (365 nm can be used to inactivate any water microorganisms with the same or less resistance that B. subtilis spores to produce safe drinking water in relatively short treatment time.

Thin-film fixed-bed reactor (TFFBR for solar photocatalytic inactivation of aquaculture pathogen Aeromonas hydrophila

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Khan Sadia J

2012-01-01

Full Text Available Abstract Background Outbreaks of infectious diseases by microbial pathogens can cause substantial losses of stock in aquaculture systems. There are several ways to eliminate these pathogens including the use of antibiotics, biocides and conventional disinfectants, but these leave undesirable chemical residues. Conversely, using sunlight for disinfection has the advantage of leaving no chemical residue and is particularly suited to countries with sunny climates. Titanium dioxide (TiO2 is a photocatalyst that increases the effectiveness of solar disinfection. In recent years, several different types of solar photocatalytic reactors coated with TiO2 have been developed for waste water and drinking water treatment. In this study a thin-film fixed-bed reactor (TFFBR, designed as a sloping flat plate reactor coated with P25 DEGUSSA TiO2, was used. Results The level of inactivation of the aquaculture pathogen Aeromonas hydrophila ATCC 35654 was determined after travelling across the TFFBR under various natural sunlight conditions (300-1200 W m-2, at 3 different flow rates (4.8, 8.4 and 16.8 L h-1. Bacterial numbers were determined by conventional plate counting using selective agar media, cultured (i under conventional aerobic conditions to detect healthy cells and (ii under conditions designed to neutralise reactive oxygen species (agar medium supplemented with the peroxide scavenger sodium pyruvate at 0.05% w/v, incubated under anaerobic conditions, to detect both healthy and sub-lethally injured (oxygen-sensitive cells. The results clearly demonstrate that high sunlight intensities (≥ 600 W m-2 and low flow rates (4.8 L h-1 provided optimum conditions for inactivation of A. hydrophila ATCC 3564, with greater overall inactivation and fewer sub-lethally injured cells than at low sunlight intensities or high flow rates. Low sunlight intensities resulted in reduced overall inactivation and greater sub-lethal injury at all flow rates. Conclusions This

Study on the inactivation of intracellular enzyme molecules by X-ray irradiation

International Nuclear Information System (INIS)

Lee, S.B.

1977-01-01

Inactivation of the glutamic acid dehydrogenase and glucose-6-phosphate dehydrogenase enzyme molecules in the Ehrlich ascites tumor cells of the mouse were studied. The above mentioned intracellular enzyme molecules were irradiated by the X-ray radiation under the condition of 65 kV, 1 Amp under the atmosphere of nitrogen gases and by 4 0 C. Thereby, irradiation doses were 580 KR/min(error: +-3%). After irradiation, the cell homogentes were prepared through liquid air techniques. There after, the activities of the enzymes were measured with photometric method given by O. Warburg and W. Christian. The dose effect curves of the activities of the two enzymes by the X-ray irradiation showed both exponential and the inactivation doses were 6.5x10 6 and 5.0x10 6 R respectively. These results showed one side that the inactivation process of the intracellular enzyme molecules was one hit reaction after target theory, and the other side that this inactivation process could not be the primary causes of the death through X-ray irradiation of the vertebrate animals, because of the high resistance of the intracellular protein molecules against X-ray irradiation. The one hit reaction by the inactivation process of the irradiated intracellular enzyme molecules was discussed. (author)

Plasma temperature during methylene blue/light treatment influences virus inactivation capacity and product quality.

Science.gov (United States)

Gravemann, U; Handke, W; Sumian, C; Alvarez, I; Reichenberg, S; Müller, T H; Seltsam, A

2018-02-27

Photodynamic treatment using methylene blue (MB) and visible light is in routine use for pathogen inactivation of human plasma in different countries. Ambient and product temperature conditions for human plasma during production may vary between production sites. The influence of different temperature conditions on virus inactivation capacity and plasma quality of the THERAFLEX MB-Plasma procedure was investigated in this study. Plasma units equilibrated to 5 ± 2°C, room temperature (22 ± 2°C) or 30 ± 2°C were treated with MB/light and comparatively assessed for the inactivation capacity for three different viruses, concentrations of MB and its photoproducts, activity of various plasma coagulation factors and clotting time. Reduced solubility of the MB pill was observed at 5 ± 2°C. Photocatalytic degradation of MB increased with increasing temperature, and the greatest formation of photoproducts (mainly azure B) occurred at 30 ± 2°C. Inactivation of suid herpesvirus, bovine viral diarrhoea virus and vesicular stomatitis virus was significantly lower at 5 ± 2°C than at higher temperatures. MB/light treatment affected clotting times and the activity of almost all investigated plasma proteins. Factor VIII (-17·7 ± 8·3%, 22 ± 2°C) and fibrinogen (-14·4 ± 16·4%, 22 ± 2°C) showed the highest decreases in activity. Increasing plasma temperatures resulted in greater changes in clotting time and higher losses of plasma coagulation factor activity. Temperature conditions for THERAFLEX MB-Plasma treatment must be carefully controlled to assure uniform quality of pathogen-reduced plasma in routine production. Inactivation of cooled plasma is not recommended. © 2018 International Society of Blood Transfusion.

High-pressure processing of apple juice: kinetics of pectin methyl esterase inactivation.

Science.gov (United States)

Riahi, Esmaeil; Ramaswamy, Hosahalli S

2003-01-01

High-pressure (HP) inactivation kinetics of pectin methyl esterase (PME) in apple juice were evaluated. Commercial PME was dispensed in clarified apple juice, sealed in dual peel sterilizable plastic bags, and subjected to different high-pressure processing conditions (200-400 MPa, 0-180 min). Residual enzyme activity was determined by a titration method estimating the rate of free carboxyl group released by the enzyme acting on pectin substrate at pH 7.5 (30 degrees C). The effects of pressure level and pressure holding time on enzyme inactivation were significant (p < 0.05). PME from the microbial source was found to be more resistant (p < 0.05) to pressure inactivation than PME from the orange peel. Almost a full decimal reduction in the activity of commercial PME was achieved by HP treatment at 400 MPa for 25 min. Inactivation kinetics were evaluated on the basis of a dual effect model involving a pressure pulse effect and a first-order rate model, and the pressure sensitivity of rate constants was modeled by using the z-value concept.

Efficient in vivo electroporation of the postnatal rodent forebrain.

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Camille Boutin

Full Text Available Functional gene analysis in vivo represents still a major challenge in biomedical research. Here we present a new method for the efficient introduction of nucleic acids into the postnatal mouse forebrain. We show that intraventricular injection of DNA followed by electroporation induces strong expression of transgenes in radial glia, neuronal precursors and neurons of the olfactory system. We present two proof-of-principle experiments to validate our approach. First, we show that expression of a human isoform of the neural cell adhesion molecule (hNCAM-140 in radial glia cells induces their differentiation into cells showing a neural precursor phenotype. Second, we demonstrate that p21 acts as a cell cycle inhibitor for postnatal neural stem cells. This approach will represent an important tool for future studies of postnatal neurogenesis and of neural development in general.

Effect of High Hydrostatic Pressure Combined with Moderate Heat to Inactivate Pressure-Resistant Bacteria in Water-Boiled Salted Duck.

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Ye, Keping; Feng, Yulin; Wang, Kai; Bai, Yun; Xu, Xinglian; Zhou, Guanghong

2015-06-01

The objective of this work was to study the effect of high hydrostatic pressure combined with moderate heat to inactivate pressure-resistant bacteria in water-boiled salted duck meat (WBSDM), and to establish suitable procedures to improve the quality of WBSDM. The conditions (300 MPa/60 °C, 400 MPa/60 °C, and 500 MPa/50 °C) effectively inactivated the pressure-resistant bacteria (Bacillus cereus and Staphylococcus warneri) in WBSDM. Although more pressure-resistant than S. warneri, the above treatment conditions inactivated B. cereus more than 10(7) CFU/mL in buffer, and more than 10(6) CFU/g in WBSDM, and did not cause any changes in color, texture, or moisture content of products. The interaction between pressure and temperature is a more significant factor than only pressure in inactivating both B. cereus and S. warneri, the treatment of WBSDM at 400 MPa/ 60 °C/ 10 min is the most practical condition for postprocess of WBSDM after cooking. © 2015 Institute of Food Technologists®

Inactivation of 1-aminocyclopropane-1-carboxylate oxidase involves oxidative modifications.

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Barlow, J N; Zhang, Z; John, P; Baldwin, J E; Schofield, C J

1997-03-25

1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the final step in the biosynthesis of the plant signaling molecule ethylene. It is a member of the ferrous iron dependent family of oxidases and dioxygenases and is unusual in that it displays a very short half-life under catalytic conditions, typically less than 20 min, and a requirement for CO2 as an activator. The rates of inactivation of purified, recombinant ACC oxidase from tomato under various combinations of substrates and cofactors were measured. Inactivation was relatively slow in the presence of buffer alone (t1/2 > 1 h), but fast in the presence of ferrous iron and ascorbate (t1/2 approximately 10 min). The rate of iron/ascorbate-mediated inactivation was increased by the addition of ACC, unaffected by the addition of CO2 at saturation (supplied as bicarbonate) but decreased by the addition of catalase or ACC + CO2 at saturation (supplied as bicarbonate). Iron/ascorbate-mediated inactivation was accompanied by partial proteolysis as observed by SDS-PAGE analysis. The fragmentation pattern was altered when ACC was also included, suggesting that ACC can bind to ACC oxidase in the absence of bicarbonate. N-terminal sequencing of fragments resulted in identification of an internal cleavage site which we propose is proximate to active-site bound iron. Thus, ACC oxidase inactivates via relatively slow partial unfolding of the catalytically active conformation, oxidative damage mediated via hydrogen peroxide which is catalase protectable and oxidative damage to the active site which results in partial proteolysis and is not catalase protectable.

Transgenic up-regulation of alpha-CaMKII in forebrain leads to increased anxiety-like behaviors and aggression

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Hasegawa Shunsuke

2009-03-01

Full Text Available Abstract Background Previous studies have demonstrated essential roles for alpha-calcium/calmodulin-dependent protein kinase II (alpha-CaMKII in learning, memory and long-term potentiation (LTP. However, previous studies have also shown that alpha-CaMKII (+/- heterozygous knockout mice display a dramatic decrease in anxiety-like and fearful behaviors, and an increase in defensive aggression. These findings indicated that alpha-CaMKII is important not only for learning and memory but also for emotional behaviors. In this study, to understand the roles of alpha-CaMKII in emotional behavior, we generated transgenic mice overexpressing alpha-CaMKII in the forebrain and analyzed their behavioral phenotypes. Results We generated transgenic mice overexpressing alpha-CaMKII in the forebrain under the control of the alpha-CaMKII promoter. In contrast to alpha-CaMKII (+/- heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in anxiety-like behaviors in open field, elevated zero maze, light-dark transition and social interaction tests, and a decrease in locomotor activity in their home cages and novel environments; these phenotypes were the opposite to those observed in alpha-CaMKII (+/- heterozygous knockout mice. In addition, similarly with alpha-CaMKII (+/- heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in aggression. However, in contrast to the increase in defensive aggression observed in alpha-CaMKII (+/- heterozygous knockout mice, alpha-CaMKII overexpressing mice display an increase in offensive aggression. Conclusion Up-regulation of alpha-CaMKII expression in the forebrain leads to an increase in anxiety-like behaviors and offensive aggression. From the comparisons with previous findings, we suggest that the expression levels of alpha-CaMKII are associated with the state of emotion; the expression level of alpha-CaMKII positively correlates with the anxiety state and strongly affects

The basal forebrain cholinergic system in aging and dementia : Rescuing cholinergic neurons from neurotoxic amyloid-beta 42 with memantine

NARCIS (Netherlands)

Nyakas, Csaba; Granic, Ivica; Halmy, Laszlo G.; Banerjee, Pradeep; Luiten, Paul G. M.

2011-01-01

The dysfunction and loss of basal forebrain cholinergic neurons and their cortical projections are among the earliest pathological events in the pathogenesis of Alzheimer's disease (AD). The evidence pointing to cholinergic impairments come from studies that report a decline in the activity of

Loss of MeCP2 From Forebrain Excitatory Neurons Leads to Cortical Hyperexcitation and Seizures

Science.gov (United States)

Zhang, Wen; Peterson, Matthew; Beyer, Barbara; Frankel, Wayne N.

2014-01-01

Mutations of MECP2 cause Rett syndrome (RTT), a neurodevelopmental disorder leading to loss of motor and cognitive functions, impaired social interactions, and seizure at young ages. Defects of neuronal circuit development and function are thought to be responsible for the symptoms of RTT. The majority of RTT patients show recurrent seizures, indicating that neuronal hyperexcitation is a common feature of RTT. However, mechanisms underlying hyperexcitation in RTT are poorly understood. Here we show that deletion of Mecp2 from cortical excitatory neurons but not forebrain inhibitory neurons in the mouse leads to spontaneous seizures. Selective deletion of Mecp2 from excitatory but not inhibitory neurons in the forebrain reduces GABAergic transmission in layer 5 pyramidal neurons in the prefrontal and somatosensory cortices. Loss of MeCP2 from cortical excitatory neurons reduces the number of GABAergic synapses in the cortex, and enhances the excitability of layer 5 pyramidal neurons. Using single-cell deletion of Mecp2 in layer 2/3 pyramidal neurons, we show that GABAergic transmission is reduced in neurons without MeCP2, but is normal in neighboring neurons with MeCP2. Together, these results suggest that MeCP2 in cortical excitatory neurons plays a critical role in the regulation of GABAergic transmission and cortical excitability. PMID:24523563

Inactivation of viable Ascaris eggs by reagents during enumeration.

Science.gov (United States)

Nelson, K L; Darby, J L

2001-12-01

Various reagents commonly used to enumerate viable helminth eggs from wastewater and sludge were evaluated for their potential to inactivate Ascaris eggs under typical laboratory conditions. Two methods were used to enumerate indigenous Ascaris eggs from sludge samples. All steps in the methods were the same except that in method I a phase extraction step with acid-alcohol (35% ethanol in 0.1 N H(2)SO(4)) and diethyl ether was used whereas in method II the extraction step was avoided by pouring the sample through a 38-microm-mesh stainless steel sieve that retained the eggs. The concentration of eggs and their viability were lower in the samples processed by method I than in the samples processed by method II by an average of 48 and 70%, respectively. A second set of experiments was performed using pure solutions of Ascaris suum eggs to elucidate the effect of the individual reagents and relevant combination of reagents on the eggs. The percentages of viable eggs in samples treated with acid-alcohol alone and in combination with diethyl ether or ethyl acetate were 52, 27, and 4%, respectively, whereas in the rest of the samples the viability was about 80%. Neither the acid nor the diethyl ether alone caused any decrease in egg viability. Thus, the observed inactivation was attributed primarily to the 35% ethanol content of the acid-alcohol solution. Inactivation of the eggs was prevented by limiting the direct exposure to the extraction reagents to 30 min and diluting the residual concentration of acid-alcohol in the sample by a factor of 100 before incubation. Also, the viability of the eggs was maintained if the acid-alcohol solution was replaced with an acetoacetic buffer. None of the reagents used for the flotation step of the sample cleaning procedure (ZnSO(4), MgSO(4), and NaCl) or during incubation (0.1 N H(2)SO(4) and 0.5% formalin) inactivated the Ascaris eggs under the conditions studied.

Weed seed inactivation in soil mesocosms via biosolarization with mature compost and tomato processing waste amendments.

Science.gov (United States)

Achmon, Yigal; Fernández-Bayo, Jesús D; Hernandez, Katie; McCurry, Dlinka G; Harrold, Duff R; Su, Joey; Dahlquist-Willard, Ruth M; Stapleton, James J; VanderGheynst, Jean S; Simmons, Christopher W

2017-05-01

Biosolarization is a fumigation alternative that combines passive solar heating with amendment-driven soil microbial activity to temporarily create antagonistic soil conditions, such as elevated temperature and acidity, that can inactivate weed seeds and other pest propagules. The aim of this study was to use a mesocosm-based field trial to assess soil heating, pH, volatile fatty acid accumulation and weed seed inactivation during biosolarization. Biosolarization for 8 days using 2% mature green waste compost and 2 or 5% tomato processing residues in the soil resulted in accumulation of volatile fatty acids in the soil, particularly acetic acid, and >95% inactivation of Brassica nigra and Solanum nigrum seeds. Inactivation kinetics data showed that near complete weed seed inactivation in soil was achieved within the first 5 days of biosolarization. This was significantly greater than the inactivation achieved in control soils that were solar heated without amendment or were amended but not solar heated. The composition and concentration of organic matter amendments in soil significantly affected volatile fatty acid accumulation at various soil depths during biosolarization. Combining solar heating with organic matter amendment resulted in accelerated weed seed inactivation compared with either approach alone. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

THERMODYNAMICS AND KINETICS OF THERMAL INACTIVATION OF PEROXIDASE FROM MANGOSTEEN (GARCINIA MANGOSTANA L. PERICARP

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MAHSA ZIABAKHSH DEYLAMI

2014-06-01

Full Text Available Mangosteen (Garcinia mangostana L. pericarp is an abundant source of phytochemicals. Blanching prior to further process stabilizes these valuable compounds. In this research, crude peroxidase (POD was extracted from mangosteen peel using Triton X-100. Kinetics of POD inactivation was studied over temperature range of 60- 100°C. The inactivation kinetics followed a monophasic first-order model with k values between 1.93×10-2- 8.14×10-2 min-1. The decreasing trend of k values with increasing temperature indicates a faster inactivation of peroxidase from mangosteen pericarp at higher temperatures. The activation energy (Ea of 35.06 kJ/mol was calculated from the slope of Arrhenius plot. Thermodynamic parameters (∆H, ∆G, ∆S for inactivation of peroxidase at different temperatures (60-100°C were studied in detail. The results of this research will help to design pre-processing conditions of mangosteen pericarp as a source of antioxidants.

X-ray induced inactivation of the capacity for photosynthetic oxygen evolution and nitrate reduction in blue-green algae

International Nuclear Information System (INIS)

Stevens, S.E. Jr.; Simic, M.G.; Rao, V.S.K.

1975-01-01

The level of inactivation of oxygen evolving photosynthesis in the green alga, Chlorella pyrenoidosa was 12 percent in N 2 at a dose of 100 krad of x irradiation. Under similar conditions, as well as under O 2 , there resulted a 20 percent inactivation of the same function in the blue-green algae, Agmenellum quadruplicatum, strains PR-6 and AQ-6. Nitrate reduction capacity in the mutant AQ-6 was inactivated to 40 percent in N 2 and to 7 percent in O 2 . Catalase and formate provided some protection from irradiation in O 2 , suggesting some inactivation by H 2 O 2 . Most of the damage to the nitrate reduction system resulted from the direct action of x irradiation on a constitutive subunit of the nitrate reductase complex. Moreover, the slight inactivation of the O 2 evolving system, a function which is associated with photosystem II, cannot account for the inactivation of nitrate reduction

Inactivation of bacteria by electric current in the presence of carbon nanotubes embedded within a polymeric membrane.

Science.gov (United States)

Zhu, Anna; Liu, Harris K; Long, Feng; Su, Erzheng; Klibanov, Alexander M

2015-01-01

Uniform conductive composite membranes were prepared using a phase inversion method by blending carboxyl-functionalized multi-walled carbon nanotubes (CNTs) with a polysulfone polymer. At 6 % of the embedded CNTs, the membrane pore size measured by transmission electron microscopy (TEM) was approximately 50 nm. Electric current in the presence of the composite membranes markedly inactivated the model pathogenic bacteria Escherichia coli and Staphylococcus aureus, with the extent of bacterial inactivation rising when the current was increased. Over 99.999 % inactivation of both bacteria was observed in deionized water after 40 min at 5 mA direct current (DC); importantly, no appreciable inactivation occurred in the absence of either the electric field or the CNTs within the membranes under otherwise the same conditions. A much lower, although still pronounced, inactivation was seen with alternating current (AC) in a 25 mM NaCl aqueous solution.

Effective inactivation of a wide range of viruses by pasteurization.

Science.gov (United States)

Gröner, Albrecht; Broumis, Connie; Fang, Randel; Nowak, Thomas; Popp, Birgit; Schäfer, Wolfram; Roth, Nathan J

2018-01-01

Careful selection and testing of plasma reduces the risk of blood-borne viruses in the starting material for plasma-derived products. Furthermore, effective measures such as pasteurization at 60°C for 10 hours have been implemented in the manufacturing process of therapeutic plasma proteins such as human albumin, coagulation factors, immunoglobulins, and enzyme inhibitors to inactivate blood-borne viruses of concern. A comprehensive compilation of the virus reduction capacity of pasteurization is presented including the effect of stabilizers used to protect the therapeutic protein from modifications during heat treatment. The virus inactivation kinetics of pasteurization for a broad range of viruses were evaluated in the relevant intermediates from more than 15 different plasma manufacturing processes. Studies were carried out under the routine manufacturing target variables, such as temperature and product-specific stabilizer composition. Additional studies were also performed under robustness conditions, that is, outside production specifications. The data demonstrate that pasteurization inactivates a wide range of enveloped and nonenveloped viruses of diverse physicochemical characteristics. After a maximum of 6 hours' incubation, no residual infectivity could be detected for the majority of enveloped viruses. Effective inactivation of a range of nonenveloped viruses, with the exception of nonhuman parvoviruses, was documented. Pasteurization is a very robust and reliable virus inactivation method with a broad effectiveness against known blood-borne pathogens and emerging or potentially emerging viruses. Pasteurization has proven itself to be a highly effective step, in combination with other complementary safety measures, toward assuring the virus safety of final product. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

Efficacy of various pasteurization time-temperature conditions in combination with homogenization on inactivation of Mycobacterium avium subsp. paratuberculosis in milk.

Science.gov (United States)

Grant, Irene R; Williams, Alan G; Rowe, Michael T; Muir, D Donald

2005-06-01

The effect of various pasteurization time-temperature conditions with and without homogenization on the viability of Mycobacterium avium subsp. paratuberculosis was investigated using a pilot-scale commercial high-temperature, short-time (HTST) pasteurizer and raw milk spiked with 10(1) to 10(5) M. avium subsp. paratuberculosis cells/ml. Viable M. avium subsp. paratuberculosis was cultured from 27 (3.3%) of 816 pasteurized milk samples overall, 5 on Herrold's egg yolk medium and 22 by BACTEC culture. Therefore, in 96.7% of samples, M. avium subsp. paratuberculosis had been completely inactivated by HTST pasteurization, alone or in combination with homogenization. Heat treatments incorporating homogenization at 2,500 lb/in2, applied upstream (as a separate process) or in hold (at the start of a holding section), resulted in significantly fewer culture-positive samples than pasteurization treatments without homogenization (P HTST pasteurization with or without homogenization was estimated to be 4.0 to 5.2 log10. The impact of homogenization on clump size distribution in M. avium subsp. paratuberculosis broth suspensions was subsequently assessed using a Mastersizer X spectrometer. These experiments demonstrated that large clumps of M. avium subsp. paratuberculosis cells were reduced to single-cell or "miniclump" status by homogenization at 2,500 lb/in2. Consequently, when HTST pasteurization was being applied to homogenized milk, the M. avium subsp. paratuberculosis cells would have been present as predominantly declumped cells, which may possibly explain the greater inactivation achieved by the combination of pasteurization and homogenization.

Efficacy of Various Pasteurization Time-Temperature Conditions in Combination with Homogenization on Inactivation of Mycobacterium avium subsp. paratuberculosis in Milk

Science.gov (United States)

Grant, Irene R.; Williams, Alan G.; Rowe, Michael T.; Muir, D. Donald

2005-01-01

The effect of various pasteurization time-temperature conditions with and without homogenization on the viability of Mycobacterium avium subsp. paratuberculosis was investigated using a pilot-scale commercial high-temperature, short-time (HTST) pasteurizer and raw milk spiked with 101 to 105 M. avium subsp. paratuberculosis cells/ml. Viable M. avium subsp. paratuberculosis was cultured from 27 (3.3%) of 816 pasteurized milk samples overall, 5 on Herrold's egg yolk medium and 22 by BACTEC culture. Therefore, in 96.7% of samples, M. avium subsp. paratuberculosis had been completely inactivated by HTST pasteurization, alone or in combination with homogenization. Heat treatments incorporating homogenization at 2,500 lb/in2, applied upstream (as a separate process) or in hold (at the start of a holding section), resulted in significantly fewer culture-positive samples than pasteurization treatments without homogenization (P pasteurization with or without homogenization was estimated to be 4.0 to 5.2 log10. The impact of homogenization on clump size distribution in M. avium subsp. paratuberculosis broth suspensions was subsequently assessed using a Mastersizer X spectrometer. These experiments demonstrated that large clumps of M. avium subsp. paratuberculosis cells were reduced to single-cell or “miniclump” status by homogenization at 2,500 lb/in2. Consequently, when HTST pasteurization was being applied to homogenized milk, the M. avium subsp. paratuberculosis cells would have been present as predominantly declumped cells, which may possibly explain the greater inactivation achieved by the combination of pasteurization and homogenization. PMID:15932977

Reactive radical-driven bacterial inactivation by hydrogen-peroxide-enhanced plasma-activated-water

Science.gov (United States)

Wu, Songjie; Zhang, Qian; Ma, Ruonan; Yu, Shuang; Wang, Kaile; Zhang, Jue; Fang, Jing

2017-08-01

The combined effects of plasma activated water (PAW) and hydrogen peroxide (H2O2), PAW/HP, in sterilization were investigated in this study. To assess the synergistic effects of PAW/HP, S. aureus was selected as the test microorganism to determine the inactivation efficacy. Also, the DNA/RNA and proteins released by the bacterial suspensions under different conditions were examined to confirm membrane integrity. Additionally, the intracellular pH (pHi) of S. aureus was measured in our study. Electron spin resonance spectroscopy (ESR) was employed to identify the presence of radicals. Finally, the oxidation reduction potential (ORP), conductivity and pH were measured. Our results revealed that the inactivation efficacy of PAW/HP is much greater than that of PAW, while increased H2O2 concentration result in higher inactivation potential. More importantly, as compared with PAW, the much stronger intensity ESR signals and higher ORP in PAW/HP suggests that the inactivation mechanism of the synergistic effects of PAW/HP: more reactive oxygen species (ROS) and reactive nitrogen species (RNS), especially OH and NO radicals, are generated in PAW combined with H2O2 resulting in more deaths of the bacteria.

Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

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Liliana Costa

2012-06-01

Full Text Available Photodynamic inactivation (PDI has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

Inactivation of a bovine enterovirus and a bovine parvovirus in cattle manure by anaerobic digestion, heat treatment, gamma irradiation, ensilage and composting

Energy Technology Data Exchange (ETDEWEB)

Monteith, H.D.; Shannon, E.E.; Derbyshire, J.B.

1986-08-01

A bovine enterovirus and a bovine parvovirus seeded into liquid cattle manure were rapidly inactivated by anaerobic digestion under thermophilic conditions (55/sup 0/C), but the same viruses survived for up to 13 and 8 days respectively under mesophilic conditions (35/sup 0/C). The enterovirus was inactivated in digested liquid manure heated to 70/sup 0/C for 30 min, but the parvovirus was not inactivated by this treatment. The enterovirus, seeded into single cell protein (the solids recovered by centrifugation of digested liquid manure), was inactivated by a gamma irradiation dose of 1.0 Mrad, but the parvovirus survived this dose. When single cell protein seeded with bovine enterovirus or bovine parvovirus was ensiled with cracked corn, the enterovirus was inactivated after a period of 30 days, while the parvovirus survived for 30 days in one of two experiments. Neither the enterovirus nor the parvovirus survived composting for 28 days in a thermophilic aerobic environment when seeded into the solid fraction of cattle manure. It was concluded that, of the procedures tested, only anaerobic digestion under thermophilic conditions appeared to be reliable method of viral inactivation to ensure the safety of single cell protein for refeeding to livestock. Composting appeared to be a suitable method for the disinfection of manure for use as a soil conditioner.

Photosensitized inactivation of DNA by monochromatic 334-nm radiation in the presence of 2-thiouracil: genetic activity and backbone breaks

International Nuclear Information System (INIS)

Peak, M.J.; Ito, A.; Peak, J.G.; Foote, C.S.

1988-01-01

Monochromatic 334-nm radiation delivered under aerobic conditions inactivates the genetic activity (ability to transform auxotrophic recipient cells to nutritional prototrophy) of isolated transforming Bacillus subtilis DNA. The presence of superoxide dismutase (SOD), catalase, and mannitol reduces the 334-nm inactivation. The rate of inactivation of the genetic activity by 334-nm radiation is enhanced fivefold by the sensitizer 2-thiouracil (s 2 Ura). This enhancement is substantially reversed when the irradiations are performed in the presence of mannitol, and, to a lesser extent, SOD. Catalase slightly reduces the s 2 Ura enhancement of 334-nm inactivation of transforming activity. Backbone breaks induced in the same DNA by aerobic 334-nm radiation were also enhanced markedly by the presence of s 2 Ura; this enhancement was reversed by the presence of mannitol and, to a lesser extent, SOD during irradiation. Catalase had no effect upon s 2 Ura-enhanced, 334-nm-induced SSBs. Whereas DNA breakage may be responsible for a portion of the inactivation of the DNA by the photosensitized reaction between s 2 Ura and 334-nm radiation, it is not the only inactivating lesion, because the yield of SSBs per lethal hit per unit length of DNA is not constant for all the irradiation conditions studied. (author)

Evaluation of eco-friendly zwitterionic detergents for enveloped virus inactivation.

Science.gov (United States)

Conley, Lynn; Tao, Yinying; Henry, Alexis; Koepf, Edward; Cecchini, Douglas; Pieracci, John; Ghose, Sanchayita

2017-04-01

Inclusion of a detergent in protein biotherapeutic purification processes is a simple and very robust method for inactivating enveloped viruses. The detergent Triton X-100 has been used for many years and is part of the production process of several commercial therapeutic proteins. However, recent ecological studies have suggested that Triton X-100 and its break-down products can potentially behave as endocrine disrupters in aquatic organisms, raising concerns from an environmental impact perspective. As such, discharge of Triton X-100 into the waste water treatment plants is regulated in some jurisdictions, and alternative detergents for viral inactivation are required. In this work, we report on the identification and evaluation of more eco-friendly detergents as viable replacements for Triton X-100. Five detergent candidates with low to moderate environmental impact were initially identified and evaluated with respect to protein stability, followed by proof-of-concept virus inactivation studies using a model enveloped virus. From the set of candidates lauryldimethylamine N-oxide (LDAO) was identified as the most promising detergent due to its low ecotoxicity, robust anti-viral activity (LRV >4 at validation set-point conditions with X-MuLX), and absence of any negative impact on protein function. This detergent exhibited effective and robust virus inactivation in a broad range of protein concentrations, solution conductivities, pHs, and in several different cell culture fluid matrices. The only process parameter which correlated with reduced virus inactivation potency was LDAO concentration, and then only when the concentration was reduced to below the detergent's critical micelle concentration (CMC). Additionally, this work also demonstrated that LDAO was cleared to below detectable levels after Protein A affinity chromatography, making it suitable for use in a platform process that utilizes this chromatographic mode for protein capture. All these findings

Cell inactivation by heavy charged particles

Energy Technology Data Exchange (ETDEWEB)

Blakely, E A [Lawrence Berkeley Lab., CA (United States). Cell and Molecular Biology Div.

1992-06-01

The inactivation of cells resulting in lethal or aberrant effects by charged particles is of growing interest. Charged particles at extremely high LET are capable of completely eliminating cell-type and cell-line differences in repair capacity. It is still not clear however whether the repair systems are inactivated, or merely that heavy-ion lesions are less repairable. Studies correlating the particle inactivation dose of radioresistant cells with intact DNA analyzed with pulse field gel electrophoresis and other techniques may be useful, but more experiments are also needed to assess the fidelity of repair. For particle irradiations between 40-100 keV/{mu}m there is however evidence for particle-induced activation of specific genes in mammalian cells, and certain repair processes in bacteria. New data are available on the inactivation of developmental processes in several systems including seeds, and cells of the nematode C. elegans. Future experimental and theoretical modeling research emphasis should focus on exploring particle-induced inactivation of endpoints assessing functionality and not just lethality, and on analyzing molecular damage and genetic effects arising in damage but non-inactivated survivors. The discrete nature of selective types of particle damage as a function of radiation quality indicates the value of accelerated ions as probes of normal and aberrant biological processes. Information obtained from molecular analyses of damage and repair must however be integrated into the context of cellular and tissue functions of the organism. (orig.).

Ablation of cdk4 and cdk6 affects proliferation of basal progenitor cells in the developing dorsal and ventral forebrain.

Science.gov (United States)

Grison, Alice; Gaiser, Carine; Bieder, Andrea; Baranek, Constanze; Atanasoski, Suzana

2018-03-23

Little is known about the molecular players driving proliferation of neural progenitor cells (NPCs) during embryonic mouse development. Here, we demonstrate that proliferation of NPCs in the developing forebrain depends on a particular combination of cell cycle regulators. We have analyzed the requirements for members of the cyclin-dependent kinase (cdk) family using cdk-deficient mice. In the absence of either cdk4 or cdk6, which are both regulators of the G1 phase of the cell cycle, we found no significant effects on the proliferation rate of cortical progenitor cells. However, concomitant loss of cdk4 and cdk6 led to a drastic decrease in the proliferation rate of NPCs, specifically the basal progenitor cells of both the dorsal and ventral forebrain at embryonic day 13.5 (E13.5). Moreover, basal progenitors in the forebrain of Cdk4;Cdk6 double mutant mice exhibited altered cell cycle characteristics. Cdk4;cdk6 deficiency led to an increase in cell cycle length and cell cycle exit of mutant basal progenitor cells in comparison to controls. In contrast, concomitant ablation of cdk2 and cdk6 had no effect on the proliferation of NCPs. Together, our data demonstrate that the expansion of the basal progenitor pool in the developing telencephalon is dependent on the presence of distinct combinations of cdk molecules. Our results provide further evidence for differences in the regulation of proliferation between apical and basal progenitors during cortical development. © 2018 Wiley Periodicals, Inc. Develop Neurobiol, 2018. © 2018 Wiley Periodicals, Inc.

The Input-Output Relationship of the Cholinergic Basal Forebrain

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Matthew R. Gielow

2017-02-01

Full Text Available Basal forebrain cholinergic neurons influence cortical state, plasticity, learning, and attention. They collectively innervate the entire cerebral cortex, differentially controlling acetylcholine efflux across different cortical areas and timescales. Such control might be achieved by differential inputs driving separable cholinergic outputs, although no input-output relationship on a brain-wide level has ever been demonstrated. Here, we identify input neurons to cholinergic cells projecting to specific cortical regions by infecting cholinergic axon terminals with a monosynaptically restricted viral tracer. This approach revealed several circuit motifs, such as central amygdala neurons synapsing onto basolateral amygdala-projecting cholinergic neurons or strong somatosensory cortical input to motor cortex-projecting cholinergic neurons. The presence of input cells in the parasympathetic midbrain nuclei contacting frontally projecting cholinergic neurons suggest that the network regulating the inner eye muscles are additionally regulating cortical state via acetylcholine efflux. This dataset enables future circuit-level experiments to identify drivers of known cortical cholinergic functions.

Ultraviolet inactivation of papain

International Nuclear Information System (INIS)

Baugher, J.F.; Grossweiner, L.I.

1975-01-01

Flash photolysis transient spectra (lambda > 250 nm) of aqueous papain showed that the initial products are the neutral tryptophan radical Trp (lambdasub(max) 510 nm), the tryptophan triplet state 3 Trp (lambdasub(max) 460 nm), the disulfide bridge electron adduct -SS - - (lambdasub(max) 420 nm) and the hydrated electron esub(aq) - . The -SS - - yield was not altered by nitrous oxide or air, indicating that the formation of this product does not involve electrons in the external medium. The original papain preparation was activated by irradiating under nitrogen. The action spectrum supports previous work attributing the low initial activity to blocking of cysteinyl site 25 with a mixed disulfide. Flask lamp irradiation in nitrogen led to activation at low starting activities and inactivation at higher starting activities, while only inactivation at the same quantum yield was observed with air saturation. The results are consistent with photoionization of an essential tryptophyl residue as the key inactivating step. (author)

Thin-film fixed-bed reactor for solar photocatalytic inactivation of Aeromonas hydrophila: influence of water quality

Directory of Open Access Journals (Sweden)

Khan Sadia J

2012-11-01

Full Text Available Abstract Background Controlling fish disease is one of the major concerns in contemporary aquaculture. The use of antibiotics or chemical disinfection cannot provide a healthy aquaculture system without residual effects. Water quality is also important in determining the success or failure of fish production. Several solar photocatalytic reactors have been used to treat drinking water or waste water without leaving chemical residues. This study has investigated the impact of several key aspects of water quality on the inactivation of the pathogenic bacterium Aeromonas hydrophila using a pilot-scale thin-film fixed-bed reactor (TFFBR system. Results The level of inactivation of Aeromonas hydrophila ATCC 35654 was determined using a TFFBR with a photocatalytic area of 0.47 m2 under the influence of various water quality variables (pH, conductivity, turbidity and colour under high solar irradiance conditions (980–1100 W m-2, at a flow rate of 4.8 L h-1 through the reactor. Bacterial enumeration were obtained through conventional plate count using trypticase soy agar media, cultured in conventional aerobic conditions to detect healthy cells and under ROS-neutralised conditions to detect both healthy and sub-lethally injured (oxygen-sensitive cells. The results showed that turbidity has a major influence on solar photocatalytic inactivation of A. hydrophila. Humic acids appear to decrease TiO2 effectiveness under full sunlight and reduce microbial inactivation. pH in the range 7–9 and salinity both have no major effect on the extent of photoinactivation or sub-lethal injury. Conclusions This study demonstrates the effectiveness of the TFFBR in the inactivation of Aeromonas hydrophila under the influence of several water quality variables at high solar irradiance, providing an opportunity for the application of solar photocatalysis in aquaculture systems, as long as turbidity remains low.

Novel AAV-based rat model of forebrain synucleinopathy shows extensive pathologies and progressive loss of cholinergic interneurons.

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Patrick Aldrin-Kirk

Full Text Available Synucleinopathies, characterized by intracellular aggregation of α-synuclein protein, share a number of features in pathology and disease progression. However, the vulnerable cell population differs significantly between the disorders, despite being caused by the same protein. While the vulnerability of dopamine cells in the substantia nigra to α-synuclein over-expression, and its link to Parkinson's disease, is well studied, animal models recapitulating the cortical degeneration in dementia with Lewy-bodies (DLB are much less mature. The aim of this study was to develop a first rat model of widespread progressive synucleinopathy throughout the forebrain using adeno-associated viral (AAV vector mediated gene delivery. Through bilateral injection of an AAV6 vector expressing human wild-type α-synuclein into the forebrain of neonatal rats, we were able to achieve widespread, robust α-synuclein expression with preferential expression in the frontal cortex. These animals displayed a progressive emergence of hyper-locomotion and dysregulated response to the dopaminergic agonist apomorphine. The animals receiving the α-synuclein vector displayed significant α-synuclein pathology including intra-cellular inclusion bodies, axonal pathology and elevated levels of phosphorylated α-synuclein, accompanied by significant loss of cortical neurons and a progressive reduction in both cortical and striatal ChAT positive interneurons. Furthermore, we found evidence of α-synuclein sequestered by IBA-1 positive microglia, which was coupled with a distinct change in morphology. In areas of most prominent pathology, the total α-synuclein levels were increased to, on average, two-fold, which is similar to the levels observed in patients with SNCA gene triplication, associated with cortical Lewy body pathology. This study provides a novel rat model of progressive cortical synucleinopathy, showing for the first time that cholinergic interneurons are vulnerable

Influvac, a trivalent inactivated subunit influenza vaccine.

Science.gov (United States)

Zuccotti, Gian Vincenzo; Fabiano, Valentina

2011-01-01

Influenza represents a major sanitary and socio-economic burden and vaccination is universally considered the most effective strategy for preventing the disease and its complications. Traditional influenza vaccines have been on the market since the late 1940s, with million of doses administered annually worldwide, and demonstrated a substantial efficacy and safety. The trivalent inactivated subunit vaccine has been available for more than 25 years and has been studied in healthy children, adults and the elderly and in people affected by underlying chronic medical conditions. We describe vaccine technology focusing on subunit vaccine production procedures and mode of action and provide updated information on efficacy and safety available data. A review of efficacy and safety data in healthy subjects and in high risk populations from major sponsor- and investigator-driven studies. The vaccine showed a good immunogenicity and a favorable safety profile in all target groups. In the panorama of actually available influenza vaccines, trivalent inactivated subunit vaccine represents a well-established tool for preventing flu and the associated complications.

Inactivation of lipoxygenase in whole soy flour suspension by ultrasonic cavitation

International Nuclear Information System (INIS)

Thakur, B.R.; Nelson, P.E.

1997-01-01

Use of ultrasound for lipoxygenase inactivation in whole soy flour suspension was studied. Inactivation of the enzyme was influenced by the time of exposure, pH, and the amplitude of ultrasound. Exposure to cavitating 20 kHz ultrasound for 3 h at pH5.0 had no effect on the activity of the enzyme. However, under similar conditions, the activity decreased by 70-85% when pH was lowered to 5.0 and 4.0, respectively. Lipoxygenase activity also decreased with increase in frequency of the ultrasound waves when pH was 5.0; above pH 5.0, increase in frequency did not affect the enzyme activity after an exposure of 1 h

Evaluation of Different Dose-Response Models for High Hydrostatic Pressure Inactivation of Microorganisms

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Sencer Buzrul

2017-09-01

Full Text Available Modeling of microbial inactivation by high hydrostatic pressure (HHP requires a plot of the log microbial count or survival ratio versus time data under a constant pressure and temperature. However, at low pressure and temperature values, very long holding times are needed to obtain measurable inactivation. Since the time has a significant effect on the cost of HHP processing it may be reasonable to fix the time at an appropriate value and quantify the inactivation with respect to pressure. Such a plot is called dose-response curve and it may be more beneficial than the traditional inactivation modeling since short holding times with different pressure values can be selected and used for the modeling of HHP inactivation. For this purpose, 49 dose-response curves (with at least 4 log10 reduction and ≥5 data points including the atmospheric pressure value (P = 0.1 MPa, and with holding time ≤10 min for HHP inactivation of microorganisms obtained from published studies were fitted with four different models, namely the Discrete model, Shoulder model, Fermi equation, and Weibull model, and the pressure value needed for 5 log10 (P5 inactivation was calculated for all the models above. The Shoulder model and Fermi equation produced exactly the same parameter and P5 values, while the Discrete model produced similar or sometimes the exact same parameter values as the Fermi equation. The Weibull model produced the worst fit (had the lowest adjusted determination coefficient (R2adj and highest mean square error (MSE values, while the Fermi equation had the best fit (the highest R2adj and lowest MSE values. Parameters of the models and also P5 values of each model can be useful for the further experimental design of HHP processing and also for the comparison of the pressure resistance of different microorganisms. Further experiments can be done to verify the P5 values at given conditions. The procedure given in this study can also be extended for

Target size analysis of bioactive substances by radiation inactivation. Comparison with electron beam and. gamma. -ray

Energy Technology Data Exchange (ETDEWEB)

Kume, Tamikazu; Watanabe, Yuhei; Ishigaki, Isao; Hirose, Shigehisa

1988-11-01

The molecular sizes of various bioactive substances can be measured by the radiation inactivation method. The high energy electron beam (10 MeV) and /sup 60/Co-..gamma.. ray are mainly used for radiation inactivation method. When the practical electron accelerator (/similar to/ 3 MeV) is used for the method, the problems such as penetration and increase of temperature will arise. In this paper the radiation inactivation using 3MeV electron beam is investigated by comparison with ..gamma..-ray. When the plate type glass ampules (glass thickness 1 +- 0.1 mm) were used as the irradiation vessels, relatively uniform dose distribution was obtained. The temperature increased only from 21 degC to 35 degC by irradiation (0.77 mA, 100 passes, 100 kGy). Under the irradiation condition mentioned above, the molecular size of three enzymes were calculated from D/sub 37/ doses. The molecular sizes obtained by electron beam and ..gamma..-ray were 14,000 and 17,000 respectively for lysozyme, 33,000 for pepsin, and 191,000 and 164,000 for yeast alcohol dehydrogenase. These values agreed closely with the reported molecular weight, suggesting that the 3 MeV electron beam can also be used for the radiation inactivation under limited conditions.

Use of isotope effects to characterize intermediates in mechanism-based inactivation of dopamine beta-monooxygenase by beta-chlorophenethylamine

International Nuclear Information System (INIS)

Bossard, M.J.; Klinman, J.P.

1990-01-01

A mechanism for beta-chlorophenethylamine inhibition of dopamine beta-monooxygenase has been postulated in which bound alpha-aminoacetophenone is generated followed by an intramolecular redox reaction to yield a ketone-derived radical cation as the inhibitory species. Based on the assumption that the ketone radical is the inhibitory intermediate, an analogous system was predicted and verified. In the present study, the role of alpha-aminoacetophenone as the proposed intermediate in the inactivation by beta-chlorophenethylamine was examined in greater detail. From the interdependence of tyramine and alpha-aminoacetophenone concentrations, ketone inactivation is concluded to occur at the substrate site as opposed to potential binding at the reductant-binding site. Using beta-[2-1H]- and beta-[2-2H]chlorophenethylamine, the magnitude of the deuterium isotope effect on inactivation under second-order conditions has been found to be identical to that observed under catalytic turnover, D(kappa inact/Ki) = D(kappa cat/Km) = 6-7. By contrast, the isotope effect on inactivation under conditions of substrate and oxygen saturation, D kappa inact = 2, is 3-fold smaller than that seen on catalytic turnover, D kappa cat = 6. This reduced isotope effect for inactivation is attributed to a normal isotope effect on substrate hydroxylation followed by an inverse isotope effect on the partitioning of the enol of alpha-aminoacetophenone between oxidation to a radical cation versus protonation to regenerate ketone. These findings are unusual in that two isotopically sensitive steps are present in the inactivation pathway whereas only one is observable in turnover

Photodynamic inactivation of four Candida species induced by photogem®

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Lívia Nordi Dovigo

2010-03-01

Full Text Available This study evaluated the in vitro susceptibility of C. albicans, C. dubliniensis, C. tropicalis and C. krusei to photodynamic therapy (PDT induced by Photogem® and light emitting diode (LED. Suspensions of each Candida strain were treated with three photosensitizer (PS concentrations (10, 25 and 50 mg/L and exposed to 18.0, 25.5 and 37.5 J/cm² LED light fluences (λ ~ 455 nm. Control suspensions were treated only with PS concentrations, only exposed to the LED light fluences or not exposed to LED light or PS. Sixteen experimental conditions were obtained and each condition was repeated three times. From each sample, serial dilutions were obtained and aliquots were plated on Sabouraud Dextrose Agar. After incubation of plates (37 ºC for 48 hours, colonies were counted (cfu/mL and the data were statistically analyzed by ANOVA and the Tukey test (α=0.05. Complete killing of C. albicans was observed after 18.0 J/cm² in association with 50 mg/L of PS. C. dubliniensis were inactivated after 18.0 J/cm² using 25 mg/L of PS. The inactivation of C. tropicalis was observed after photosensitization with 25 mg/L and subsequent illumination at 25.5 J/cm². For C. krusei, none of the associations between PS and light resulted in complete killing of this species. PDT proved to be effective for the inactivation of C. albicans, C. dubliniensis and C. tropicalis. In addition, reduction in the viability of C. krusei was achieved with some of the PS and light associations.

Inactivation of Salmonella and Listeria in ground chicken breast meat during thermal processing.

Science.gov (United States)

Murphy, R Y; Marks, B P; Johnson, E R; Johnson, M G

1999-09-01

Thermal inactivation of six Salmonella spp. and Listeria innocua was evaluated in ground chicken breast and liquid medium. Survival of Salmonella and Listeria was affected by the medium composition. Under the same thermal process condition, significantly more Salmonella and Listeria survived in chicken breast meat than in 0.1% peptone-agar solution. The thermal lethality of six tested Salmonella spp. was additive in chicken meat. Survival of Listeria in chicken meat during thermal processing was not affected by the presence of the six Salmonella spp. Sample size and shape affected the inactivation of Salmonella and Listeria in chicken meat during thermal processing.

Inactivation of enteroviruses in sewage with ozone

Energy Technology Data Exchange (ETDEWEB)

Ivanova, O.E.; Bogdanov, M.V.; Kazantseva, V.A.; Gabrilevskaia, L.N.; Kodkind, G.K.H.

The study of ozone inactivation of enteroviruses in sewage showed the presence in sewage of suspensions of organic origin and bacterial flora to influence the rate of inactivation. The inactivation rate of poliomyelitis virus in sewage free from organic suspension and bacterial flora was significantly higher than that in sewage containing such suspension and bacterial flora. The inactivation rate of enteroviruses was found not to depend upon the protein and salt composition and pH of sewage or strain appurtenance of viruses. The inactivation rate of enteroviruses directly depended upon the dose of ozone and time of contact with it. Differences in the resistance of different types of poliomyelitis virus, ECHO and Coxsackie viruses to the effect of ozone are likely exist. These differences are manifested within the range of relatively small doses of ozone. E. coli is more resistant to ozone than entero-viruses. The results of laboratory studies were used to choose the regimen of sanitation of urban sewage to be used in technological cycles of industrial enterprises.

An Evolutionarily Conserved Network Mediates Development of the zona limitans intrathalamica, a Sonic Hedgehog-Secreting Caudal Forebrain Signaling Center

Directory of Open Access Journals (Sweden)

Elena Sena

2016-10-01

Full Text Available Recent studies revealed new insights into the development of a unique caudal forebrain-signaling center: the zona limitans intrathalamica (zli. The zli is the last brain signaling center to form and the first forebrain compartment to be established. It is the only part of the dorsal neural tube expressing the morphogen Sonic Hedgehog (Shh whose activity participates in the survival, growth and patterning of neuronal progenitor subpopulations within the thalamic complex. Here, we review the gene regulatory network of transcription factors and cis-regulatory elements that underlies formation of a shh-expressing delimitated domain in the anterior brain. We discuss evidence that this network predates the origin of chordates. We highlight the contribution of Shh, Wnt and Notch signaling to zli development and discuss implications for the fact that the morphogen Shh relies on primary cilia for signal transduction. The network that underlies zli development also contributes to thalamus induction, and to its patterning once the zli has been set up. We present an overview of the brain malformations possibly associated with developmental defects in this gene regulatory network (GRN.

Mycobacteria inactivation using Engineered Water Nanostructures (EWNS).

Science.gov (United States)

Pyrgiotakis, Georgios; McDevitt, James; Gao, Ya; Branco, Alan; Eleftheriadou, Mary; Lemos, Bernardo; Nardell, Edward; Demokritou, Philip

2014-08-01

Airborne transmitted pathogens such as Mycobacterium tuberculosis (Mtb) cause serious, often fatal infectious disease with enormous global health implications. Due to their unique cell wall and slow growth, mycobacteria are among the most resilient microbial forms. Herein we evaluate the ability of an emerging, chemical-free, nanotechnology-based method to inactivate M. parafortuitum (Mtb surrogate). This method is based on the transformation of atmospheric water vapor into engineered water nano-structures (EWNS) via electrospray. We demonstrate that the EWNS can interact with and inactivate airborne mycobacteria, reducing their concentration levels significantly. Additionally, EWNS can inactivate M. parafortuitum on surfaces eight times faster than the control. The mechanism of mycobacteria inactivation was also investigated in this study. It was demonstrated that the EWNS effectively deliver the reactive oxygen species, encapsulated during the electrospray process, to the bacteria oxidizing their cell membrane resulting into inactivation. Overall, this is a method with the potential to become an effective intervention technology in the battle against airborne infections. This study demonstrates the feasibility of mycobacterium inactivation in airborne form or on contact surfaces using electrospray activated water nano-structures. Given that the method is free of toxic chemicals, this might become an important tool in the prevention of mycobacterial infections, which are notoriously hard to treat. Copyright © 2014 Elsevier Inc. All rights reserved.

Genetic ablation of Dicer in adult forebrain neurons results in abnormal tau hyperphosphorylation and neurodegeneration

DEFF Research Database (Denmark)

Hébert, Sébastien S; Papadopoulou, Aikaterini S; Smith, Pascal

2010-01-01

, particularly in the adult brain, remain poorly defined. Here we show that the absence of Dicer in the adult forebrain is accompanied by a mixed neurodegenerative phenotype. Although neuronal loss is observed in the hippocampus, cellular shrinkage is predominant in the cortex. Interestingly, neuronal...... degeneration coincides with the hyperphosphorylation of endogenous tau at several epitopes previously associated with neurofibrillary pathology. Transcriptome analysis of enzymes involved in tau phosphorylation identified ERK1 as one of the candidate kinases responsible for this event in vivo. We further...

Effect of water content and temperature on inactivation kinetics of myrosinase in broccoli (Brassica oleracea var. italica).

Science.gov (United States)

Oliviero, T; Verkerk, R; Van Boekel, M A J S; Dekker, M

2014-11-15

Broccoli belongs to the Brassicaceae plant family consisting of widely eaten vegetables containing high concentrations of glucosinolates. Enzymatic hydrolysis of glucosinolates by endogenous myrosinase (MYR) can form isothiocyanates with health-promoting activities. The effect of water content (WC) and temperature on MYR inactivation in broccoli was investigated. Broccoli was freeze dried obtaining batches with WC between 10% and 90% (aw from 0.10 to 0.96). These samples were incubated for various times at different temperatures (40-70°C) and MYR activity was measured. The initial MYR inactivation rates were estimated by the first-order reaction kinetic model. MYR inactivation rate constants were lower in the driest samples (10% WC) at all studied temperatures. Samples with 67% and 90% WC showed initial inactivation rate constants all in the same order of magnitude. Samples with 31% WC showed intermediate initial inactivation rate constants. These results are useful to optimise the conditions of drying processes to produce dried broccoli with optimal MYR retention for human health. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Estradiol on Neurotrophin Receptors in Basal Forebrain Cholinergic Neurons: Relevance for Alzheimer's Disease.

Science.gov (United States)

Kwakowsky, Andrea; Milne, Michael R; Waldvogel, Henry J; Faull, Richard L

2016-12-17

The basal forebrain is home to the largest population of cholinergic neurons in the brain. These neurons are involved in a number of cognitive functions including attention, learning and memory. Basal forebrain cholinergic neurons (BFCNs) are particularly vulnerable in a number of neurological diseases with the most notable being Alzheimer's disease, with evidence for a link between decreasing cholinergic markers and the degree of cognitive impairment. The neurotrophin growth factor system is present on these BFCNs and has been shown to promote survival and differentiation on these neurons. Clinical and animal model studies have demonstrated the neuroprotective effects of 17β-estradiol (E2) on neurodegeneration in BFCNs. It is believed that E2 interacts with neurotrophin signaling on cholinergic neurons to mediate these beneficial effects. Evidence presented in our recent study confirms that altering the levels of circulating E2 levels via ovariectomy and E2 replacement significantly affects the expression of the neurotrophin receptors on BFCN. However, we also showed that E2 differentially regulates neurotrophin receptor expression on BFCNs with effects depending on neurotrophin receptor type and neuroanatomical location. In this review, we aim to survey the current literature to understand the influence of E2 on the neurotrophin system, and the receptors and signaling pathways it mediates on BFCN. In addition, we summarize the physiological and pathophysiological significance of E2 actions on the neurotrophin system in BFCN, especially focusing on changes related to Alzheimer's disease.

In vitro studies of chlorin e6-assisted photodynamic inactivation of Helicobacter pylori

Science.gov (United States)

Simon, C.; Mohrbacher, C.; Hüttenberger, D.; Bauer-Marschall, Ina; Krickhahn, C.; Stachon, A.; Foth, H.-J.

2014-03-01

Helicobacter pylori (HP), a gram-negative microaerophilic bacterium located in gastric mucosa, plays an im- portant role in gastro carcinogenesis. Due to the increasing emergence of antibiotic resistance, photodynamic inactivation of bacteria presents a new approach to treat bacterial infections, like HP. In vitro experiments were performed to determine the irradiation conditions for a complete inactivation of HP with the photosensitizer Chlorin e6 (Ce6). The HP strain CCUG 38770 (Culture Collection, University of Gothenburg, Sweden) was routinely cultured under microaerophilic conditions, suspended in sodium chloride, incubated with Ce6 and irradiated briefly with red light of the appropriate wavelength of λ = 660 nm. Series of measurements of different Ce6-concentrations (0.1 μM - 100 μM) were carried out, whereby the incubation time was kept constant at 1 min. The absorbed energy dose has been selected in varying the irradiation time (1 s - 300 s) and the power density (4.5 mW/cm2 - 31 mW/cm2 ). Quantification of inactivation was performed by enumeration of the grown colonies. In addition, the accumulation of Ce6 in HP cells was studied more precisely by uorescence spectroscopy. With a Ce6 concentration of 100 μM and a power density of 9 mW cm2 , a 6-log10 reduction in the survival rate of HP was achieved within 30 seconds of irradiation. In conclusion the most relevant factor for the inactivation of HP is the exposure time of irradiation, followed by the concentration of Ce6 and the light intensity. Further studies with HP strains obtained from patient specimens are under current investigation.

Thrombin-specific inactivation of endothelial cell derived plasminogen activator

International Nuclear Information System (INIS)

Highsmith, R.F.; Gallaher, M.J.

1986-01-01

Although thrombin (T) has diverse functions in the overall hemostatic mechanism, relatively little is known about its direct effect on components of the fibrinolytic enzyme system. The authors have investigated the interaction of T with plasminogen activators (PA) derived from bovine aortic endothelial cells (EC) in culture (2-5th passage, preconfluent monolayers). Varying concentrations of purified bovine or human thrombin were added to EC-conditioned media (CM). CM + T mixtures were assayed at various times for PA activity using purified plasminogen and a sensitive 125 I-fibrinogenolytic or caseinolytic assay. T (5 nM), but not plasmin or trypsin at equivalent concentrations, resulted in a time-dependent inhibition of the PA activity in CM. T had no effect on the PA activity of urokinase, streptokinase or preformed plasmin. The ability of T to inactivate the EC-derived PA was abolished by prior treatment of T with active site-directed reagents. SDS-PAGE and zymography with copolymerized fibrinogen and plasminogen revealed further specificity in that only one of the multiple-molecular weight forms of PA present in EC-CM was inactivated by T. The authors conclude that in a highly specific fashion, T inactivates the predominant PA present in EC-CM by limited proteolysis. Thus, another potentially important function of T is suggested which may have particular significance in the temporal regulation of coagulation and fibrinolysis at the blood-endothelium interface

Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology

International Nuclear Information System (INIS)

Hossain, Md. Sohrab; Nik Ab Rahman, Nik Norulaini; Balakrishnan, Venugopal; Alkarkhi, Abbas F.M.; Ahmad Rajion, Zainul; Ab Kadir, Mohd Omar

2015-01-01

Highlights: • Supercritical carbon dioxide sterilization of clinical solid waste. • Inactivation of bacteria in clinical solid waste using supercritical carbon dioxide. • Reduction of the hazardous exposure of clinical solid waste. • Optimization of the supercritical carbon dioxide experimental conditions. - Abstract: Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO 2 ) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO 2 sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO 2 -treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO 2 exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials

Optimizing supercritical carbon dioxide in the inactivation of bacteria in clinical solid waste by using response surface methodology

Energy Technology Data Exchange (ETDEWEB)

Hossain, Md. Sohrab [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Nik Ab Rahman, Nik Norulaini [School of Distance Education, Universiti Sains Malaysia, 11800 Penang (Malaysia); Balakrishnan, Venugopal [Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 Penang (Malaysia); Alkarkhi, Abbas F.M. [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Ahmad Rajion, Zainul [School of Dental Science, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia); Ab Kadir, Mohd Omar, E-mail: akmomar@usm.my [Department of Environmental Technology, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia)

2015-04-15

Highlights: • Supercritical carbon dioxide sterilization of clinical solid waste. • Inactivation of bacteria in clinical solid waste using supercritical carbon dioxide. • Reduction of the hazardous exposure of clinical solid waste. • Optimization of the supercritical carbon dioxide experimental conditions. - Abstract: Clinical solid waste (CSW) poses a challenge to health care facilities because of the presence of pathogenic microorganisms, leading to concerns in the effective sterilization of the CSW for safe handling and elimination of infectious disease transmission. In the present study, supercritical carbon dioxide (SC-CO{sub 2}) was applied to inactivate gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, and gram-negative Escherichia coli in CSW. The effects of SC-CO{sub 2} sterilization parameters such as pressure, temperature, and time were investigated and optimized by response surface methodology (RSM). Results showed that the data were adequately fitted into the second-order polynomial model. The linear quadratic terms and interaction between pressure and temperature had significant effects on the inactivation of S. aureus, E. coli, E. faecalis, and B. subtilis in CSW. Optimum conditions for the complete inactivation of bacteria within the experimental range of the studied variables were 20 MPa, 60 °C, and 60 min. The SC-CO{sub 2}-treated bacterial cells, observed under a scanning electron microscope, showed morphological changes, including cell breakage and dislodged cell walls, which could have caused the inactivation. This espouses the inference that SC-CO{sub 2} exerts strong inactivating effects on the bacteria present in CSW, and has the potential to be used in CSW management for the safe handling and recycling-reuse of CSW materials.

[Kinetics of catalase inactivation induced by ultrasonic cavitation].

Science.gov (United States)

Potapovich, M V; Eremin, A N; Metelitsa, D I

2003-01-01

Kinetic patterns of sonication-induced inactivation of bovine liver catalase (CAT) were studied in buffer solutions (pH 4-11) within the temperature range from 36 to 55 degrees C. Solutions of CAT were exposed to low-frequency (20.8 kHz) ultrasound (specific power, 48-62 W/cm2). The kinetics of CAT inactivation was characterized by effective first-order rate constants (s-1) of total inactivation (kin), thermal inactivation (*kin), and ultrasonic inactivation (kin(us)). In all cases, the following inequality was valid: kin > *kin. The value of kin(us) increased with the ultrasound power (range, 48-62 W/cm2) and exhibited a strong dependence on pH of the medium. On increasing the initial concentration of CAT (0.4-4.0 nM), kin(us) decreased. The three rate constants were minimum within the range of pH 6.5-8; their values increased considerably at pH 9. At 36-55 degrees C, temperature dependence of kin(us) was characterized by an activation energy (Eact) of 19.7 kcal/mol, whereas the value of Eact for CAT thermoinactivation was equal to 44.2 kcal/mol. Bovine serum and human serum albumins (BSA and HSA, respectively) inhibited sonication-induced CAT inactivation; complete prevention was observed at concentrations above 2.5 micrograms/ml. Dimethyl formamide (DMFA), a scavenger of hydroxyl radicals (HO.), prevented sonication-induced CAT inactivation at 10% (kin and *kin increased with the content of DMFA at concentrations in excess of 3%). The results obtained indicate that free radicals generated in the field of ultrasonic cavitation play a decisive role in the inactivation of CAT, which takes place when its solutions are exposed to low-frequency ultrasound. However, the efficiency of CAT inactivation by the radicals is determined by (1) the degree of association between the enzyme molecules in the reaction medium and (2) the composition thereof.

Cationic antimicrobial peptides inactivate Shiga toxin-encoding bacteriophages

Science.gov (United States)

Del Cogliano, Manuel E.; Hollmann, Axel; Martinez, Melina; Semorile, Liliana; Ghiringhelli, Pablo D.; Maffía, Paulo C.; Bentancor, Leticia V.

2017-12-01

Shiga toxin (Stx) is the principal virulence factor during Shiga toxin-producing Escherichia coli (STEC) infections. We have previously reported the inactivation of bacteriophage encoding Stx after treatment with chitosan, a linear polysaccharide polymer with cationic properties. Cationic antimicrobial peptides (cAMPs) are short linear aminoacidic sequences, with a positive net charge, which display bactericidal or bacteriostatic activity against a wide range of bacterial species. They are promising novel antibiotics since they have shown bactericidal effects against multiresistant bacteria. To evaluate whether cationic properties are responsible for bacteriophage inactivation, we tested seven cationic peptides with proven antimicrobial activity as anti-bacteriophage agents, and one random sequence cationic peptide with no antimicrobial activity as a control. We observed bacteriophage inactivation after incubation with five cAMPs, but no inactivating activity was observed with the random sequence cationic peptide or with the non alpha helical cAMP Omiganan. Finally, to confirm peptide-bacteriophage interaction, zeta potential was analyzed by following changes on bacteriophage surface charges after peptide incubation. According to our results we could propose that: 1) direct interaction of peptides with phage is a necessary step for bacteriophage inactivation, 2) cationic properties are necessary but not sufficient for bacteriophage inactivation, and 3) inactivation by cationic peptides could be sequence (or structure) specific. Overall our data suggest that these peptides could be considered a new family of molecules potentially useful to decrease bacteriophage replication and Stx expression.

Cationic Antimicrobial Peptides Inactivate Shiga Toxin-Encoding Bacteriophages

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Manuel E. Del Cogliano

2017-12-01

Full Text Available Shiga toxin (Stx is the principal virulence factor during Shiga toxin-producing Escherichia coli (STEC infections. We have previously reported the inactivation of bacteriophage encoding Stx after treatment with chitosan, a linear polysaccharide polymer with cationic properties. Cationic antimicrobial peptides (cAMPs are short linear aminoacidic sequences, with a positive net charge, which display bactericidal or bacteriostatic activity against a wide range of bacterial species. They are promising novel antibiotics since they have shown bactericidal effects against multiresistant bacteria. To evaluate whether cationic properties are responsible for bacteriophage inactivation, we tested seven cationic peptides with proven antimicrobial activity as anti-bacteriophage agents, and one random sequence cationic peptide with no antimicrobial activity as a control. We observed bacteriophage inactivation after incubation with five cAMPs, but no inactivating activity was observed with the random sequence cationic peptide or with the non-alpha helical cAMP Omiganan. Finally, to confirm peptide-bacteriophage interaction, zeta potential was analyzed by following changes on bacteriophage surface charges after peptide incubation. According to our results we could propose that: (1 direct interaction of peptides with phage is a necessary step for bacteriophage inactivation, (2 cationic properties are necessary but not sufficient for bacteriophage inactivation, and (3 inactivation by cationic peptides could be sequence (or structure specific. Overall our data suggest that these peptides could be considered a new family of molecules potentially useful to decrease bacteriophage replication and Stx expression.

“Redundancy” of Endocannabinoid Inactivation: New Challenges and Opportunities for Pain Control

Science.gov (United States)

2012-01-01

Redundancy of metabolic pathways and molecular targets is a typical feature of all lipid mediators, and endocannabinoids, which were originally defined as endogenous agonists at cannabinoid CB1 and CB2 receptors, are no exception. In particular, the two most studied endocannabinoids, anandamide and 2-arachidonoylglycerol, are inactivated through alternative biochemical routes, including hydrolysis and oxidation, and more than one enzyme might be used even for the same type of inactivating reaction. These enzymes also recognize as substrates other concurrent lipid mediators, whereas, in turn, endocannabinoids might interact with noncannabinoid receptors with subcellular distribution and ultimate biological actions either similar to or completely different from those of cannabinoid receptors. Even splicing variants of endocannabinoid hydrolyzing enzymes, such as FAAH-1, might play distinct roles in endocannabinoid inactivation. Finally, the products of endocannabinoid catabolism may have their own targets, with biological roles different from those of cannabinoid receptors. These peculiarities of endocannabinoid signaling have complicated the use of inhibitors of its inactivation mechanisms as a safer and more efficacious alternative to the direct targeting of cannabinoid receptors for the treatment of several pathological conditions, including pain. However, new strategies, including the rediscovery of “dirty drugs”, and the use of certain natural products (including non-THC cannabis constituents), are emerging that might allow us to make a virtue of necessity and exploit endocannabinoid redundancy to develop new analgesics. PMID:22860203

Modelling and application of the inactivation of microorganism

International Nuclear Information System (INIS)

Oğuzhan, P.; Yangılar, F.

2013-01-01

Prevention of consuming contaminated food with toxic microorganisms causing infections and consideration of food protection and new microbial inactivation methods are obligatory situations. Food microbiology is mainly related with unwanted microorganisms spoiling foods during processing and transporting stages and causing diseases. Determination of pathogen microorganisms is important for human health to define and prevent dangers and elongate shelf life. Inactivation of pathogen microorganisms can provide food security and reduce nutrient losses. Microbial inactivation which is using methods of food protection such as food safety and fresh. With this aim, various methods are used such as classical thermal processes (pasteurisation, sterilisation), pressured electrical field (PEF), ionised radiation, high pressure, ultrasonic waves and plasma sterilisation. Microbial inactivation modelling is a secure and effective method in food production. A new microbiological application can give useful results for risk assessment in food, inactivation of microorganisms and improvement of shelf life. Application and control methods should be developed and supported by scientific research and industrial applications

Whole-Brain Monosynaptic Afferent Inputs to Basal Forebrain Cholinergic System

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Rongfeng Hu

2016-10-01

Full Text Available The basal forebrain cholinergic system (BFCS robustly modulates many important behaviors, such as arousal, attention, learning and memory, through heavy projections to cortex and hippocampus. However, the presynaptic partners governing BFCS activity still remain poorly understood. Here, we utilized a recently developed rabies virus-based cell-type-specific retrograde tracing system to map the whole-brain afferent inputs of the BFCS. We found that the BFCS receives inputs from multiple cortical areas, such as orbital frontal cortex, motor cortex, and insular cortex, and that the BFCS also receives dense inputs from several subcortical nuclei related to motivation and stress, including lateral septum (LS, central amygdala (CeA, paraventricular nucleus of hypothalamus (PVH, dorsal raphe (DRN and parabrachial nucleus (PBN. Interestingly, we found that the BFCS receives inputs from the olfactory areas and the entorhinal-hippocampal system. These results greatly expand our knowledge about the connectivity of the mouse BFCS and provided important preliminary indications for future exploration of circuit function.

Adolescent Intermittent Alcohol Exposure: Deficits in Object Recognition Memory and Forebrain Cholinergic Markers.

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H Scott Swartzwelder

Full Text Available The long-term effects of intermittent ethanol exposure during adolescence (AIE are of intensive interest and investigation. The effects of AIE on learning and memory and the neural functions that drive them are of particular interest as clinical findings suggest enduring deficits in those cognitive domains in humans after ethanol abuse during adolescence. Although studies of such deficits after AIE hold much promise for identifying mechanisms and therapeutic interventions, the findings are sparse and inconclusive. The present results identify a specific deficit in memory function after AIE and establish a possible neural mechanism of that deficit that may be of translational significance. Male rats (starting at PND-30 received exposure to AIE (5g/kg, i.g. or vehicle and were allowed to mature into adulthood. At PND-71, one group of animals was assessed using the spatial-temporal object recognition (stOR test to evaluate memory function. A separate group of animals was used to assess the density of cholinergic neurons in forebrain areas Ch1-4 using immunohistochemistry. AIE exposed animals manifested deficits in the temporal component of the stOR task relative to controls, and a significant decrease in the number of ChAT labeled neurons in forebrain areas Ch1-4. These findings add to the growing literature indicating long-lasting neural and behavioral effects of AIE that persist into adulthood and indicate that memory-related deficits after AIE depend upon the tasks employed, and possibly their degree of complexity. Finally, the parallel finding of diminished cholinergic neuron density suggests a possible mechanism underlying the effects of AIE on memory and hippocampal function as well as possible therapeutic or preventive strategies for AIE.

Pulsed electric field processing of different fruit juices: impact of pH and temperature on inactivation of spoilage and pathogenic micro-organisms.

Science.gov (United States)

Timmermans, R A H; Nierop Groot, M N; Nederhoff, A L; van Boekel, M A J S; Matser, A M; Mastwijk, H C

2014-03-03

Pulsed electrical field (PEF) technology can be used for the inactivation of micro-organisms and therefore for preservation of food products. It is a mild technology compared to thermal pasteurization because a lower temperature is used during processing, leading to a better retention of the quality. In this study, pathogenic and spoilage micro-organisms relevant in refrigerated fruit juices were studied to determine the impact of process parameters and juice composition on the effectiveness of the PEF process to inactivate the micro-organisms. Experiments were performed using a continuous-flow PEF system at an electrical field strength of 20 kV/cm with variable frequencies to evaluate the inactivation of Salmonella Panama, Escherichia coli, Listeria monocytogenes and Saccharomyces cerevisiae in apple, orange and watermelon juices. Kinetic data showed that under the same conditions, S. cerevisiae was the most sensitive micro-organism, followed by S. Panama and E. coli, which displayed comparable inactivation kinetics. L. monocytogenes was the most resistant micro-organism towards the treatment conditions tested. A synergistic effect between temperature and electric pulses was observed at inlet temperatures above 35 °C, hence less energy for inactivation was required at higher temperatures. Different juice matrices resulted in a different degree of inactivation, predominantly determined by pH. The survival curves were nonlinear and could satisfactorily be modeled with the Weibull model. Copyright © 2013 Elsevier B.V. All rights reserved.

Inactivation of RNA viruses by gamma irradiation

International Nuclear Information System (INIS)

Nonomiya, Takashi; Morimoto, Akinori; Iwatsuki, Kazuo; Tsutsumi, Takamasa; Ito, Hitoshi; Yamashiro, Tomio; Ishigaki, Isao.

1992-01-01

Four kinds of RNA viruses, Bluetongue virus (BT), Bovine Virus Diarrhea-Mucosal Disease virus (BVD·MD), Bovine Respiratory Syncytial virus (RS), Vesicular Stmatitis virus (VS), were subjected to various doses of gamma irradiation to determine the lethal doses. The D 10 values, which are the dose necessary to decimally reduce infectivity, ranged from 1.5 to 3.4 kGy under frozen condition at dry-ice temperature, and they increased to 2.6 to 5.0 kGy under frozen condition at dry-ice temperature. Serum neutralzing antibody titer of Infectious Bovine Rhinotracheitis (IBR) was not adversely changed by the exposure to 36 kGy of gamma-rays under frozen condition. Analysis of electrophoresis patterns of the bovine serum also reveales that the serum proteins were not remarkably affected, even when exposed to 36 kGy of gamma radiation under frozen condition. The results suggested that gamma irradiation under frozen condition is an effective means for inactivating both DNA and RNA viruses without adversely affecting serum proteins and neutralizing antibody titer. (author)

Inactivation of RNA viruses by gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Nonomiya, Takashi; Morimoto, Akinori; Iwatsuki, Kazuo; Tsutsumi, Takamasa (Ministry of Agriculture, Forestry and fisheries, Yokohama, Kanagawa (Japan). Animal Quarantine Service); Ito, Hitoshi; Yamashiro, Tomio; Ishigaki, Isao

1992-09-01

Four kinds of RNA viruses, Bluetongue virus (BT), Bovine Virus Diarrhea-Mucosal Disease virus (BVD[center dot]MD), Bovine Respiratory Syncytial virus (RS), Vesicular Stmatitis virus (VS), were subjected to various doses of gamma irradiation to determine the lethal doses. The D[sub 10] values, which are the dose necessary to decimally reduce infectivity, ranged from 1.5 to 3.4 kGy under frozen condition at dry-ice temperature, and they increased to 2.6 to 5.0 kGy under frozen condition at dry-ice temperature. Serum neutralzing antibody titer of Infectious Bovine Rhinotracheitis (IBR) was not adversely changed by the exposure to 36 kGy of gamma-rays under frozen condition. Analysis of electrophoresis patterns of the bovine serum also reveales that the serum proteins were not remarkably affected, even when exposed to 36 kGy of gamma radiation under frozen condition. The results suggested that gamma irradiation under frozen condition is an effective means for inactivating both DNA and RNA viruses without adversely affecting serum proteins and neutralizing antibody titer. (author).

Gaultherin Production From Gandapura Gaultheria Fragantissima By Enzymatic Inactivation Of Gaultherase

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Ari Yuniastuti

2017-03-01

Full Text Available Gaultherin is the active form of salicylate from plants Gandapura. Gaultherin has some characterictics which make it potential to become a natural aspirin anti-cancer antiinflamatory dan cardiopulmonary. Currently aspirin acetylsalicylic acid is a medicine which is used by most of the people in this world because of its function as antipiretic antiinflamatory and analgesic. Approximately the need of pharmacy industry towards gaultherin will be increased in the following year. However at the time being there is still no any effective methods to produce gaultherin from gandapura. This difficulty in the process of taking gaultherin is based on the process of its extraction where the tissue is broken so gaultherin will be hydrolyzed change to be its individual components like methyl salicylate and disaccharides. The hydrolysis process is believed to be catalyzed by the enzyme gaultherase inside. This research is aimed to analyze the production of gaultherin form gandapura using the gaultherase enzyme inactivation process through extraction with alcoholic solvent and determine the correct condition to get the highest production of gaultherin. The result of the calculation shows that the bioextraction process variables of gaultherase enzyme inactivation which is mostly influential are pH and alcohol concentration. The more pH extraction will increase the outcome of gaultherin active compounds The optimum condition of bioextraction enzyme inactivation is in pH 8 with 1446 gaultherin active compounds and regression equation in . The bigger solvent concentration the more gaultherin be extracted. The production of gaultherin will optimally reached in the 90 concentration of ethanol with the result of 1310 active compounds

Differentiation of Forebrain and Hippocampal Dopamine 1-Class Receptors, D1R and D5R, in Spatial Learning and Memory

Science.gov (United States)

Sariñana, Joshua; Tonegawa, Susumu

2017-01-01

Activation of prefrontal cortical (PFC), striatal, and hippocampal dopamine 1-class receptors (D1R and D5R) is necessary for normal spatial information processing. Yet the precise role of the D1R versus the D5R in the aforementioned structures, and their specific contribution to the water-maze spatial learning task remains unknown. D1R- and D5R- specific in situ hybridization probes showed that forebrain restricted D1R and D5R KO mice (F-D1R/D5R KO) displayed D1R mRNA deletion in the medial (m)PFC, dorsal and ventral striatum, and the dentate gyrus (DG) of the hippocampus. D5R mRNA deletion was limited to the mPFC, the CA1 and DG hippocampal subregions. F-D1R/D5R KO mice were given water-maze training and displayed subtle spatial latency differences between genotypes and spatial memory deficits during both regular and reversal training. To differentiate forebrain D1R from D5R activation, forebrain restricted D1R KO (F-D1R KO) and D5R KO (F-D5R KO) mice were trained on the water-maze task. F-D1R KO animals exhibited escape latency deficits throughout regular and reversal training as well as spatial memory deficits during reversal training. F-D1R KO mice also showed perseverative behavior during the reversal spatial memory probe test. In contrast, F-D5R KO animals did not present observable deficits on the water-maze task. Because F-D1R KO mice showed water-maze deficits we tested the necessity of hippocampal D1R activation for spatial learning and memory. We trained DG restricted D1R KO (DG-D1R KO) mice on the water-maze task. DG-D1R KO mice did not present detectable spatial memory deficit, but did show subtle deficits during specific days of training. Our data provides evidence that forebrain D5R activation plays a unique role in spatial learning and memory in conjunction with D1R activation. Moreover, these data suggest that mPFC and striatal, but not DG D1R activation are essential for spatial learning and memory. PMID:26174222

Removal of detergents from SDS-inactivated dextransucrase

International Nuclear Information System (INIS)

Husman, D.W.; Mayer, R.M.

1986-01-01

Dextransucrase, which is rapidly inactivated by SDS, can be reactivated upon the addition of Triton X-100. Purification of the enzyme, in good yield and homogeneity, has been achieved by chromatography in the presence of SDS. The purified enzyme can be reactivated with Triton, but has large amounts of detergents. It was important to develop procedures for their removal. Density gradient centrifugation of SDS-inactivated or Triton-reactivated enzyme, treatment with Extracti-Gel D (Pierce) or chromatography on hydroxyl apatite (HA), have been examined for their effectiveness in providing detergent-free enzyme in good yield. Ultracentrifugation of SDS-inactivated protein provided limited recovery of active enzyme, but suggested that reactivation could be achieved by the simple removal of the detergent. While similar behavior was observed when the enzyme was eluted from Extracti-Gel, it was also shown that the limited recovery was a result of irreversible inactivation of the enzyme. Recovery could be improved if the enzyme was collected in solutions containing Triton, which has been reported to be a stabilizer. Chromatography of SDS-inactivated enzyme on HA also yielded active enzyme. Good recovery was obtained when Triton-reactivated enzyme was employed in these studies. The degree of detergent removal was determined by utilizing radiolabelled SDS and Triton X-100

Neuropeptide Y in the olfactory system, forebrain and pituitary of the teleost, Clarias batrachus.

Science.gov (United States)

Gaikwad, Archana; Biju, K C; Saha, Subhash G; Subhedar, Nishikant

2004-03-01

Distribution of neuropeptide Y (NPY)-like immunoreactivity in the forebrain of catfish Clarias batrachus was examined with immunocytochemistry. Conspicuous immunoreactivity was seen in the olfactory receptor neurons (ORNs), their projections in the olfactory nerve, fascicles of the olfactory nerve layer in the periphery of bulb and in the medial olfactory tracts as they extend to the telencephalic lobes. Ablation of the olfactory organ resulted in loss of immunoreactivity in the olfactory nerve layer of the bulb and also in the fascicles of the medial olfactory tracts. This evidence suggests that NPY may serve as a neurotransmitter in the ORNs and convey chemosensory information to the olfactory bulb, and also to the telencephalon over the extrabulbar projections. In addition, network of beaded immunoreactive fibers was noticed throughout the olfactory bulb, which did not respond to ablation experiment. These fibers may represent centrifugal innervation of the bulb. Strong immunoreactivity was encountered in some ganglion cells of nervus terminalis. Immunoreactive fibers and terminal fields were widely distributed in the telencephalon. Several neurons of nucleus entopeduncularis were moderately immunoreactive; and a small population of neurons in nucleus preopticus periventricularis was also labeled. Immunoreactive terminal fields were particularly conspicuous in the preoptic, the tuberal areas, and the periventricular zone around the third ventricle and inferior lobes. NPY immunoreactive cells and fibers were detected in all the lobes of the pituitary gland. Present results describing the localization of NPY in the forebrain of C. batrachus are in concurrence with the pattern of the immunoreactivity encountered in other teleosts. However, NPY in olfactory system of C. batrachus is a novel feature that suggests a role for the peptide in processing of chemosensory information.

Luciferase inactivation in the luminous marine bacterium Vibrio harveyi.

Science.gov (United States)

Reeve, C A; Baldwin, T O

1981-06-01

Luciferase was rapidly inactivated in stationary-phase cultures of the wild type of the luminous marine bacterium Vibrio harveyi, but was stable in stationary-phase cultures of mutants of V. harveyi that are nonluminous without exogenous aldehyde, termed the aldehyde-deficient mutants. The inactivation in the wild type was halted by cell lysis and was slowed or stopped by O2 deprivation or by addition of KCN and NaF or of chloramphenicol. If KCN and NaF or chloramphenicol were added to a culture before the onset of luciferase inactivation, then luciferase inactivation did not occur. However, if these inhibitors were added after the onset of luciferase inactivation, then luciferase inactivation continued for about 2 to 3 h before the inactivation process stopped. The onset of luciferase inactivation in early stationary-phase cultures of wild-type cell coincided with a slight drop in the intracellular adenosine 5'-triphosphate (ATP) level from a relatively constant log-phase value of 20 pmol of ATP per microgram of soluble cell protein. Addition of KCN and NaF to a culture shortly after this drop in ATP caused a rapid decrease in the ATP level to about 4 pmol of ATP per microgram whereas chloramphenicol added at this same time caused a transient increase in ATP level to about 25 pmol/microgram. The aldehyde-deficient mutant (M17) showed a relatively constant log-phase ATP level identical with that of the wild-type cells, but rather than decreasing in early stationary phase, the ATP level increased to a value twice that in log-phase cells. We suggest that the inactivation of luciferase is dependent on the synthesis of some factor which is produced during stationary phase and is itself unstable, and whose synthesis is blocked by chloramphenicol or cyanide plus fluoride.

Comparison of two different methods for inactivation of viruses in serum

DEFF Research Database (Denmark)

Preuss, T.; Kamstrup, Søren; Kyvsgaard, N.C.

1997-01-01

enterovirus (PEV) was inactivated within 3 h, The inactivation with electron-beam irradiation resulted in almost linear curves in a semilogarithmic plot of virus titer versus irradiation dose, reflecting a first-order inactivation, The rate of inactivation was almost twice as fast in the liquid samples...

Turnover-dependent inactivation of the nitrogenase MoFe-protein at high pH.

Science.gov (United States)

Yang, Kun-Yun; Haynes, Chad A; Spatzal, Thomas; Rees, Douglas C; Howard, James B

2014-01-21

Proton uptake accompanies the reduction of all known substrates by nitrogenase. As a consequence, a higher pH should limit the availability of protons as a substrate essential for turnover, thereby increasing the proportion of more highly reduced forms of the enzyme for further study. The utility of the high-pH approach would appear to be problematic in view of the observation reported by Pham and Burgess [(1993) Biochemistry 32, 13725-13731] that the MoFe-protein undergoes irreversible protein denaturation above pH 8.65. In contrast, we found by both enzyme activity and crystallographic analyses that the MoFe-protein is stable when incubated at pH 9.5. We did observe, however, that at higher pHs and under turnover conditions, the MoFe-protein is slowly inactivated. While a normal, albeit low, level of substrate reduction occurs under these conditions, the MoFe-protein undergoes a complex transformation; initially, the enzyme is reversibly inhibited for substrate reduction at pH 9.5, yet in a second, slower process, the MoFe-protein becomes irreversibly inactivated as measured by substrate reduction activity at the optimal pH of 7.8. The final inactivated MoFe-protein has an increased hydrodynamic radius compared to that of the native MoFe-protein, yet it has a full complement of iron and molybdenum. Significantly, the modified MoFe-protein retains the ability to specifically interact with its nitrogenase partner, the Fe-protein, as judged by the support of ATP hydrolysis and by formation of a tight complex with the Fe-protein in the presence of ATP and aluminum fluoride. The turnover-dependent inactivation coupled to conformational change suggests a mechanism-based transformation that may provide a new probe of nitrogenase catalysis.

Mechanism of Bacillus subtilis spore inactivation by and resistance to supercritical CO2 plus peracetic acid.

Science.gov (United States)

Setlow, B; Korza, G; Blatt, K M S; Fey, J P; Setlow, P

2016-01-01

Determine how supercritical CO2 (scCO2 ) plus peracetic acid (PAA) inactivates Bacillus subtilis spores, factors important in spore resistance to scCO2 -PAA, and if spores inactivated by scCO2 -PAA are truly dead. Spores of wild-type B. subtilis and isogenic mutants lacking spore protective proteins were treated with scCO2 -PAA in liquid or dry at 35°C. Wild-type wet spores (aqueous suspension) were more susceptible than dry spores. Treated spores were examined for viability (and were truly dead), dipicolinic acid (DPA), mutations, permeability to nucleic acid stains, germination under different conditions, energy metabolism and outgrowth. ScCO2 -PAA-inactivated spores retained DPA, and survivors had no notable DNA damage. However, DPA was released from inactivated spores at a normally innocuous temperature (85°C), and colony formation from treated spores was salt sensitive. The inactivated spores germinated but did not outgrow, and these germinated spores had altered plasma membrane permeability and defective energy metabolism. Wet or dry coat-defective spores had increased scCO2 -PAA sensitivity, and dry spores but not wet spores lacking DNA protective proteins were more scCO2 -PAA sensitive. These findings suggest that scCO2 -PAA inactivates spores by damaging spores' inner membrane. The spore coat provided scCO2 -PAA resistance for both wet and dry spores. DNA protective proteins provided scCO2 -PAA resistance only for dry spores. These results provide information on mechanisms of spore inactivation of and resistance to scCO2 -PAA, an agent with increasing use in sterilization applications. © 2015 The Society for Applied Microbiology.

Effective heat inactivation of Mycobacterium avium subsp. paratuberculosis in raw milk contaminated with naturally infected feces.

Science.gov (United States)

Rademaker, Jan L W; Vissers, Marc M M; Te Giffel, Meike C

2007-07-01

The effectiveness of high-temperature, short holding time (HTST) pasteurization and homogenization with respect to inactivation of Mycobacterium avium subsp. paratuberculosis was evaluated quantitatively. This allowed a detailed determination of inactivation kinetics. High concentrations of feces from cows with clinical symptoms of Johne's disease were used to contaminate raw milk in order to realistically mimic possible incidents most closely. Final M. avium subsp. paratuberculosis concentrations varying from 10(2) to 3.5 x 10(5) cells per ml raw milk were used. Heat treatments including industrial HTST were simulated on a pilot scale with 22 different time-temperature combinations, including 60 to 90 degrees C at holding (mean residence) times of 6 to 15 s. Following 72 degrees C and a holding time of 6 s, 70 degrees C for 10 and 15 s, or under more stringent conditions, no viable M. avium subsp. paratuberculosis cells were recovered, resulting in >4.2- to >7.1-fold reductions, depending on the original inoculum concentrations. Inactivation kinetic modeling of 69 quantitative data points yielded an E(a) of 305,635 J/mol and an lnk(0) of 107.2, corresponding to a D value of 1.2 s at 72 degrees C and a Z value of 7.7 degrees C. Homogenization did not significantly affect the inactivation. The conclusion can be drawn that HTST pasteurization conditions equal to 15 s at > or =72 degrees C result in a more-than-sevenfold reduction of M. avium subsp. paratuberculosis.

Effective Heat Inactivation of Mycobacterium avium subsp. paratuberculosis in Raw Milk Contaminated with Naturally Infected Feces▿

Science.gov (United States)

Rademaker, Jan L. W.; Vissers, Marc M. M.; te Giffel, Meike C.

2007-01-01

The effectiveness of high-temperature, short holding time (HTST) pasteurization and homogenization with respect to inactivation of Mycobacterium avium subsp. paratuberculosis was evaluated quantitatively. This allowed a detailed determination of inactivation kinetics. High concentrations of feces from cows with clinical symptoms of Johne's disease were used to contaminate raw milk in order to realistically mimic possible incidents most closely. Final M. avium subsp. paratuberculosis concentrations varying from 102 to 3.5 × 105 cells per ml raw milk were used. Heat treatments including industrial HTST were simulated on a pilot scale with 22 different time-temperature combinations, including 60 to 90°C at holding (mean residence) times of 6 to 15 s. Following 72°C and a holding time of 6 s, 70°C for 10 and 15 s, or under more stringent conditions, no viable M. avium subsp. paratuberculosis cells were recovered, resulting in >4.2- to >7.1-fold reductions, depending on the original inoculum concentrations. Inactivation kinetic modeling of 69 quantitative data points yielded an Ea of 305,635 J/mol and an lnk0 of 107.2, corresponding to a D value of 1.2 s at 72°C and a Z value of 7.7°C. Homogenization did not significantly affect the inactivation. The conclusion can be drawn that HTST pasteurization conditions equal to 15 s at ≥72°C result in a more-than-sevenfold reduction of M. avium subsp. paratuberculosis. PMID:17496131

Photodynamic inactivation of foodborne bacteria by eosin Y.

Science.gov (United States)

Bonin, E; Dos Santos, A R; Fiori da Silva, A; Ribeiro, L H; Favero, M E; Campanerut-Sá, P A Z; de Freitas, C F; Caetano, W; Hioka, N; Mikcha, J M G

2018-03-25

The aim of this study was evaluate the effect of photodynamic inactivation mediated by eosin Y in Salmonella enterica serotype Typhimurium ATCC 14028, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Bacillus cereus ATCC 11778. Bacteria (10 7 CFU per ml) were incubated with eosin Y at concentrations ranging from 0·1 to 10 μmol l -1 , irradiated by green LED (λ max 490-570 nm) for 5, 10 and 15 min and the cellular viability was determined. Pseudomonas aeruginosa was completely inactivated when treated with 10 μmol l -1 eosin Y for 10 min. Treatments reduced B. cereus and Salm. Typhimurium counts to 2·7 log CFU per ml and 1·7 log CFU per ml, respectively. Escherichia coli counts were slightly reduced. Staphylococcus aureus presented the highest sensitivity, being completely inactivated by eosin Y at 5 μmol l -1 and 5 min of illumination. The reduction of cellular viability of photoinactivated Staph. aureus was also demonstrated by flow cytometry and morphological changes were observed by scanning electron microscopy. Eosin Y in combination with LED produced bacterial inactivation, being a potential candidate for photodynamic inactivation. This study evidenced the efficacy of photodynamic inactivation as a novel and promising alternative to bacterial control. © 2018 The Society for Applied Microbiology.

Dose-related gene expression changes in forebrain following acute, low-level chlorpyrifos exposure in neonatal rats

International Nuclear Information System (INIS)

Ray, Anamika; Liu Jing; Ayoubi, Patricia; Pope, Carey

2010-01-01

Chlorpyrifos (CPF) is a widely used organophosphorus insecticide (OP) and putative developmental neurotoxicant in humans. The acute toxicity of CPF is elicited by acetylcholinesterase (AChE) inhibition. We characterized dose-related (0.1, 0.5, 1 and 2 mg/kg) gene expression profiles and changes in cell signaling pathways 24 h following acute CPF exposure in 7-day-old rats. Microarray experiments indicated that approximately 9% of the 44,000 genes were differentially expressed following either one of the four CPF dosages studied (546, 505, 522, and 3,066 genes with 0.1, 0.5, 1.0 and 2.0 mg/kg CPF). Genes were grouped according to dose-related expression patterns using K-means clustering while gene networks and canonical pathways were evaluated using Ingenuity Pathway Analysis (registered) . Twenty clusters were identified and differential expression of selected genes was verified by RT-PCR. The four largest clusters (each containing from 276 to 905 genes) constituted over 50% of all differentially expressed genes and exhibited up-regulation following exposure to the highest dosage (2 mg/kg CPF). The total number of gene networks affected by CPF also rose sharply with the highest dosage of CPF (18, 16, 18 and 50 with 0.1, 0.5, 1 and 2 mg/kg CPF). Forebrain cholinesterase (ChE) activity was significantly reduced (26%) only in the highest dosage group. Based on magnitude of dose-related changes in differentially expressed genes, relative numbers of gene clusters and signaling networks affected, and forebrain ChE inhibition only at 2 mg/kg CPF, we focused subsequent analyses on this treatment group. Six canonical pathways were identified that were significantly affected by 2 mg/kg CPF (MAPK, oxidative stress, NFΚB, mitochondrial dysfunction, arylhydrocarbon receptor and adrenergic receptor signaling). Evaluation of different cellular functions of the differentially expressed genes suggested changes related to olfactory receptors, cell adhesion/migration, synapse

Thrombin-specific inactivation of endothelial cell derived plasminogen activator

Energy Technology Data Exchange (ETDEWEB)

Highsmith, R.F.; Gallaher, M.J.

1986-03-05

Although thrombin (T) has diverse functions in the overall hemostatic mechanism, relatively little is known about its direct effect on components of the fibrinolytic enzyme system. The authors have investigated the interaction of T with plasminogen activators (PA) derived from bovine aortic endothelial cells (EC) in culture (2-5th passage, preconfluent monolayers). Varying concentrations of purified bovine or human thrombin were added to EC-conditioned media (CM). CM + T mixtures were assayed at various times for PA activity using purified plasminogen and a sensitive /sup 125/I-fibrinogenolytic or caseinolytic assay. T (5 nM), but not plasmin or trypsin at equivalent concentrations, resulted in a time-dependent inhibition of the PA activity in CM. T had no effect on the PA activity of urokinase, streptokinase or preformed plasmin. The ability of T to inactivate the EC-derived PA was abolished by prior treatment of T with active site-directed reagents. SDS-PAGE and zymography with copolymerized fibrinogen and plasminogen revealed further specificity in that only one of the multiple-molecular weight forms of PA present in EC-CM was inactivated by T. The authors conclude that in a highly specific fashion, T inactivates the predominant PA present in EC-CM by limited proteolysis. Thus, another potentially important function of T is suggested which may have particular significance in the temporal regulation of coagulation and fibrinolysis at the blood-endothelium interface.

Effect of Estradiol on Neurotrophin Receptors in Basal Forebrain Cholinergic Neurons: Relevance for Alzheimer’s Disease

Science.gov (United States)

Kwakowsky, Andrea; Milne, Michael R.; Waldvogel, Henry J.; Faull, Richard L.

2016-01-01

The basal forebrain is home to the largest population of cholinergic neurons in the brain. These neurons are involved in a number of cognitive functions including attention, learning and memory. Basal forebrain cholinergic neurons (BFCNs) are particularly vulnerable in a number of neurological diseases with the most notable being Alzheimer’s disease, with evidence for a link between decreasing cholinergic markers and the degree of cognitive impairment. The neurotrophin growth factor system is present on these BFCNs and has been shown to promote survival and differentiation on these neurons. Clinical and animal model studies have demonstrated the neuroprotective effects of 17β-estradiol (E2) on neurodegeneration in BFCNs. It is believed that E2 interacts with neurotrophin signaling on cholinergic neurons to mediate these beneficial effects. Evidence presented in our recent study confirms that altering the levels of circulating E2 levels via ovariectomy and E2 replacement significantly affects the expression of the neurotrophin receptors on BFCN. However, we also showed that E2 differentially regulates neurotrophin receptor expression on BFCNs with effects depending on neurotrophin receptor type and neuroanatomical location. In this review, we aim to survey the current literature to understand the influence of E2 on the neurotrophin system, and the receptors and signaling pathways it mediates on BFCN. In addition, we summarize the physiological and pathophysiological significance of E2 actions on the neurotrophin system in BFCN, especially focusing on changes related to Alzheimer’s disease. PMID:27999310

Effect of Estradiol on Neurotrophin Receptors in Basal Forebrain Cholinergic Neurons: Relevance for Alzheimer’s Disease

Directory of Open Access Journals (Sweden)

Andrea Kwakowsky

2016-12-01

Full Text Available The basal forebrain is home to the largest population of cholinergic neurons in the brain. These neurons are involved in a number of cognitive functions including attention, learning and memory. Basal forebrain cholinergic neurons (BFCNs are particularly vulnerable in a number of neurological diseases with the most notable being Alzheimer’s disease, with evidence for a link between decreasing cholinergic markers and the degree of cognitive impairment. The neurotrophin growth factor system is present on these BFCNs and has been shown to promote survival and differentiation on these neurons. Clinical and animal model studies have demonstrated the neuroprotective effects of 17β-estradiol (E2 on neurodegeneration in BFCNs. It is believed that E2 interacts with neurotrophin signaling on cholinergic neurons to mediate these beneficial effects. Evidence presented in our recent study confirms that altering the levels of circulating E2 levels via ovariectomy and E2 replacement significantly affects the expression of the neurotrophin receptors on BFCN. However, we also showed that E2 differentially regulates neurotrophin receptor expression on BFCNs with effects depending on neurotrophin receptor type and neuroanatomical location. In this review, we aim to survey the current literature to understand the influence of E2 on the neurotrophin system, and the receptors and signaling pathways it mediates on BFCN. In addition, we summarize the physiological and pathophysiological significance of E2 actions on the neurotrophin system in BFCN, especially focusing on changes related to Alzheimer’s disease.

Multi-Layered TiO2 Films towards Enhancement of Escherichia coli Inactivation

Directory of Open Access Journals (Sweden)

Sorachon Yoriya

2016-09-01

Full Text Available Crystalline TiO2 has shown its great photocatalytic properties in bacterial inactivation. This work presents a design fabrication of low-cost, layered TiO2 films assembled reactors and a study of their performance for a better understanding to elucidate the photocatalytic effect on inactivation of E. coli in water. The ability to reduce the number of bacteria in water samples for the layered TiO2 composing reactors has been investigated as a function of time, while varying the parameters of light sources, initial concentration of bacteria, and ratios of TiO2 film area and volume of water. Herein, the layered TiO2 films have been fabricated on the glass plates by thermal spray coating prior to screen printing, allowing a good adhesion of the films. Surface topology and crystallographic phase of TiO2 for the screen-printed active layer have been characterized, resulting in the ratio of anatase:rutile being 80:20. Under exposure to sunlight and a given condition employed in this study, the optimized film area:water volume of 1:2.62 has shown a significant ability to reduce the E. coli cells in water samples. The ratio of surface area of photocatalytic active base to volume of water medium is believed to play a predominant role facilitating the cells inactivation. The kinetic rate of inactivation and its behavior are also described in terms of adsorption of reaction species at different contact times.

Experience in applying 60Co γ-rays for careful production of inactivated influenza virus vaccines

International Nuclear Information System (INIS)

Nordheim, W.; Braeuniger, S.; Schulze, P.; Dittmann, S.; Petzold, G.; Teupel, D.; Luther, P.; Tischner, H.; Baer, M.; Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung)

1987-01-01

Radiation doses between 12 and 13 kGy at 15-20 0 C were sufficient for mild inactivation of influenza viruses. Under these conditions the decisive surface antigens hemagglutinin and neuraminidase were treated with care, and the preparations of influenza viruses revealed good immunogenicity in the animal experiment. Morphologic alterations after application of 20 kGy could not be demonstrated in electron microscopic investigations. Doses of 9.5-9.9 kGy in combination with a very low quantity of HCHO (1:15000) is sufficient for inactivation. Reactivation of influenza viruses after treatment could not be demonstrated. (author)

Deficits in Docosahexaenoic Acid Accrual during Adolescence Reduce Rat Forebrain White Matter Microstructural Integrity: An in vivo Diffusion Tensor Imaging Study.

Science.gov (United States)

McNamara, Robert K; Schurdak, Jennifer D; Asch, Ruth H; Peters, Bart D; Lindquist, Diana M

2018-01-01

Neuropsychiatric disorders that frequently initially emerge during adolescence are associated with deficits in the omega-3 (n-3) fatty acid docosahexaenoic acid (DHA), elevated proinflammatory signaling, and regional reductions in white matter integrity (WMI). This study determined the effects of altering brain DHA accrual during adolescence on WMI in the rat brain by diffusion tensor imaging (DTI), and investigated the potential mediating role of proinflammatory signaling. During periadolescent development, male rats were fed a diet deficient in n-3 fatty acids (DEF, n = 20), a fish oil-fortified diet containing preformed DHA (FO, n = 20), or a control diet (CON, n = 20). In adulthood, DTI scans were performed and brain WMI was determined using voxelwise tract-based spatial statistics (TBSS). Postmortem fatty acid composition, peripheral (plasma IL-1β, IL-6, and C-reactive protein [CRP]) and central (IL-1β and CD11b mRNA) proinflammatory markers, and myelin basic protein (MBP) mRNA expression were determined. Compared with CON rats, forebrain DHA levels were lower in DEF rats and higher in FO rats. Compared with CON rats, DEF rats exhibited greater radial diffusivity (RD) and mean diffusivity in the right external capsule, and greater axial diffusivity in the corpus callosum genu and left external capsule. DEF rats also exhibited greater RD than FO rats in the right external capsule. Forebrain MBP expression did not differ between groups. Compared with CON rats, central (IL-1β and CD11b) and peripheral (IL-1β and IL-6) proinflammatory markers were not different in DEF rats, and DEF rats exhibited lower CRP levels. These findings demonstrate that deficits in adolescent DHA accrual negatively impact forebrain WMI, independently of elevated proinflammatory signaling. © 2017 S. Karger AG, Basel.

Inactivation of catalase monolayers by irradiation with 100 keV electrons

International Nuclear Information System (INIS)

Hahn, M.; Seredynski, J.; Baumeister, W.

1976-01-01

A catalase monolayer adsorbed on a layer of arachidic acid deposited on a solid support was irradiated with 100 keV electrons simulating the conditions of electron microscopic imaging. Effective doses were calculated taking into account the angular and energy distribution of backscattered electrons. Enzymatic inactivation was chosen as the criterion for damage and was monitored by a rapid and quantifiable but nevertheless sensitive assay. Dose-response curves revealed that inactivation is a one-hit--multiple-target phenomenon, which is consistent with biochemical evidence for a cooperative function of subunits. The experimentally determined target size coincides fairly well with both calculated cross sections for inelastic interactions based on the atomic composition of catalase and with calculated cross sections for ionizing events based on the chemical bonds involved. This legitimates both types of calculations even for complex biomolecules

Effect of iron salt counter ion in dose-response curves for inactivation of Fusarium solani in water through solar driven Fenton-like processes

Science.gov (United States)

Aurioles-López, Verónica; Polo-López, M. Inmaculada; Fernández-Ibáñez, Pilar; López-Malo, Aurelio; Bandala, Erick R.

2016-02-01

The inactivation of Fusarium solani in water was assessed by solar driven Fenton-like processes using three different iron salts: ferric acetylacetonate (Fe(acac)3), ferric chloride (FeCl3) and ferrous sulfate (FeSO4). The experimental conditions tested were [Fe] ≈ 5 mg L-1, [H2O2] ≈ 10 mg L-1 and [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1 mild and high, respectively, and pH 3.0 and 5.0, under solar radiation. The highest inactivation rates were observed at high reaction conditions for the three iron salts tested at pH 5.0 with less than 3.0 kJ L-1 of accumulate energy (QUV) to achieve over 99.9% of F. solani inactivation. Fe(acac)3 was the best iron salt to accomplishing F. solani inactivation. The modified Fermi equation was used to fix the experimental inactivation, data showed it was helpful for modeling the process, adequately describing dose-response curves. Inactivation process using FeSO4 at pH 3.0 was modeled fairly with r2 = 0.98 and 0.99 (mild and high concentration, respectively). Fe(acac)3, FeCl3 and FeSO4 at high concentration (i.e. [Fe] ≈ 10 mg L-1; [H2O2] ≈ 20 mg L-1) and pH 5.0 showed the highest fitting values (r2 = 0.99). Iron salt type showed a remarkable influence on the Fenton-like inactivation process.

Physiological and Morphological Characterization of Organotypic Cocultures of the Chick Forebrain Area MNH and its Main Input Area DMA/DMP

OpenAIRE

Endepols, Heike; Jungnickel, Julia; Braun, Katharina

2001-01-01

Cocultures of the learning-relevant forebrain region mediorostrai neostriatum and hyperstriatum ventrale (MNH) and its main glutamatergic input area nucleus dorsomedialis anterior thalami/posterior thalami were morphologically and physiologically characterized. Synaptic contacts of thalamic fibers were lightand electron-microscopically detected on MNH neurons by applying the fluorescence tracer DiI-C18(3) into the thalamus part of the coculture. Most thalamic syn...

Inactivation of viruses in municipal effluent by chlorine.

OpenAIRE

Hajenian, H. G.; Butler, M.

1980-01-01

The influence of pH and temperature on the efficiency of chlorine inactivation of two unrelated picornaviruses in a typical urban wastewater effluent was examined. Temperature, unlike pH, had relatively little effect on the rate of inactivation. The pH effect was complex and the two viruses differed. The f2 coliphage was more sensitive to chlorine at low pH, but at all values there was a threshold above which additional chlorine resulted in very rapid inactivation. The amount of chlorine requ...

Effect of chelators and nisin produced in situ on inhibition and inactivation of gram negatives.

Science.gov (United States)

Boziaris, I S; Adams, M R

1999-12-15

The ability of chelators and nisin generated in situ to inhibit and inactivate E. coli and other gram negatives in a model substrate was investigated. The effect of various chelators and different concentrations of exogenous nisin on inhibition of E. coli in broth medium showed that only EDTA and pyrophosphates were able to cause appreciable inhibition of E. coli by nisin. In a broth where L. lactis NCFB 497 produced nisin in a concentration of 250-300 IU/ml, pyrophosphates were unable to inactivate E. coli. Under the same conditions, addition of EDTA led to inactivation of E. coli at neutral and slightly acidic pH only. A cocktail of strains of E. coli was less sensitive than E. coli ATCC 25922 alone. Pseudomonas aeruginosa was more sensitive and salmonellae more resistant. EDTA also caused a slight reduction in the L. lactis population and its biochemical activity as regards pH drop and acid production. Some of the inhibition of E. coli could be ascribed to the physical presence of Lactococcus cells rather than their metabolites excreted into the medium. Failure to observe any inhibition in fermented broths at their natural pH (4.0) was ascribed to the poor chelating power of EDTA under acid conditions.

Inactivation of complement by Loxosceles reclusa spider venom.

Science.gov (United States)

Gebel, H M; Finke, J H; Elgert, K D; Cambell, B J; Barrett, J T

1979-07-01

Zymosan depletion of serum complement in guinea pigs rendered them highly resistant to lesion by Loxosceles reclusa spider venom. Guinea pigs deficient in C4 of the complement system are as sensitive to the venom as normal guinea pigs. The injection of 35 micrograms of whole recluse venom intradermally into guinea pigs lowered their complement level by 35.7%. Brown recluse spider venom in concentrations as slight as 0.02 micrograms protein/ml can totally inactivate one CH50 of guinea pig complement in vitro. Bee, scorpion, and other spider venoms had no influence on the hemolytic titer of complement. Fractionation of recluse spider venom by Sephadex G-200 filtration separated the complement-inactivating property of the venom into three major regions which could be distinguished on the basis of heat stability as well as size. None was neutralized by antivenom. Polyacrylamide gel electrophoresis of venom resolved the complement inactivators into five fractions. Complement inactivated by whole venom or the Sephadex fractions could be restored to hemolytic activity by supplements of fresh serum but not by heat-inactivated serum, pure C3, pure C5, or C3 and C5 in combination.

Randomized Trials Comparing Inactivated Vaccine after Medium- or High-titer Measles Vaccine with Standard Titer Measles Vaccine after Inactivated Vaccine

DEFF Research Database (Denmark)

Aaby, Peter; Ravn, Henrik; Benn, Christine S.

2016-01-01

Background: Observational studies have suggested that girls have higher mortality if their most recent immunization is an inactivated vaccine rather than a live vaccine. We therefore reanalyzed 5 randomized trials of early measles vaccine (MV) in which it was possible to compare an inactivated va...

Chromosomal gene inactivation in the green sulfur bacterium Chlorobium tepidum by natural transformation

DEFF Research Database (Denmark)

Frigaard, N-U; Bryant, D A

2001-01-01

Conditions for inactivating chromosomal genes of Chlorobium tepidum by natural transformation and homologous recombination were established. As a model, mutants unable to perform nitrogen fixation were constructed by interrupting nifD with various antibiotic resistance markers. Growth of wild...

Germination and Inactivation of Alicyclobacillus acidoterrestris Spores Induced by Moderate Hydrostatic Pressure.

Science.gov (United States)

Sokołowska, Barbara; Skapska, Sylwia; Fonberg-Broczek, Monika; Niezgoda, Jolanta; Porebska, Izabela; Dekowska, Agnieszka; Rzoska, Sylwester J

2015-01-01

Given the importance of spoilage caused by Alicyclobacillus acidoterrestris for the fruit juice industry, the objective of this work was to study the germination and inactivation of A. acidoterrestris spores induced by moderate hydrostatic pressure. Hydrostatic pressure treatment can induce the germination and inactivation of A. acidoterrestris spores. At low pH, spore germination of up to 3.59-3.75 log and inactivation of 1.85-2.04 log was observed in a low pressure window (200-300 MPa) applied at 50 degrees C for 20 min. Neutral pH suppressed inactivation, the number of spores inactivated at pH 7.0 was only 0.24-1.06 log. The pressurization temperature significantly affected spore germination and inactivation. The degree of germination in apple juice after pressurization for 30 min with 200 MPa at 20 degrees C was 2.04 log, with only 0.61 log of spores being inactivated, while at 70 degrees C spore germination was 5.94 log and inactivation 4.72 log. This temperature strongly stimulated germination and inactivation under higher (500 MPa) than lower (200 MPa) pressure. When the oscillatory mode was used, the degree of germination and inactivation was slightly higher than at continuous mode. The degree of germination and inactivation was inversely proportional to the soluble solids content and was lowest in concentrated apple juice.

Inactivation of human and simian rotaviruses by ozone

Energy Technology Data Exchange (ETDEWEB)

Vaughn, J.M.; Chen, Y.S.; Lindburg, K.; Morales, D.

1987-09-01

The inactivation of simian rotavirus Sa-11 and human rotavirus type 2 (Wa) by ozone was compared at 4/sup 0/C by using single-particle virus stocks. Although the human strain was clearly more sensitive, both virus types were rapidly inactivated by ozone concentrations of 0.25 mg/liter or greater at all pH levels tested. Comparison of the virucidal activity of ozone with that of chlorine in identical experiments indicated little significant difference in rotavirus-inactivating efficiencies when the disinfectants were used at concentrations of 0.25 mg/liter or greater.

Esterase resistant to inactivation by heavy metals

KAUST Repository

El, Dorry Hamza

2014-09-25

EstATII is an esterase that a halotolerant, thermophilic and resistant to a spectrum of heavy metals including toxic concentration of metals. It was isolated from the lowest convective layer of the Atlantis II Red Sea brine pool. The Atlantis II brine pool is an extreme environment that possesses multiple harsh conditions such as; high temperature, salinity, pH and high concentration of metals, including toxic heavy metals. A fosmid metagenomic library using DNA isolated from the lowest convective layer this pool was used to identify EstATII. Polynucleotides encoding EstATII and similar esterases are disclosed and can be used to make EstATII. EstATII or compositions or apparatuses that contain it may be used in various processes employing lipases/esterases especially when these processes are performed under harsh conditions that inactivate other kinds of lipases or esterases.

Mutual inactivation of Notch receptors and ligands facilitates developmental patterning.

Directory of Open Access Journals (Sweden)

David Sprinzak

2011-06-01

Full Text Available Developmental patterning requires juxtacrine signaling in order to tightly coordinate the fates of neighboring cells. Recent work has shown that Notch and Delta, the canonical metazoan juxtacrine signaling receptor and ligand, mutually inactivate each other in the same cell. This cis-interaction generates mutually exclusive sending and receiving states in individual cells. It generally remains unclear, however, how this mutual inactivation and the resulting switching behavior can impact developmental patterning circuits. Here we address this question using mathematical modeling in the context of two canonical pattern formation processes: boundary formation and lateral inhibition. For boundary formation, in a model motivated by Drosophila wing vein patterning, we find that mutual inactivation allows sharp boundary formation across a broader range of parameters than models lacking mutual inactivation. This model with mutual inactivation also exhibits robustness to correlated gene expression perturbations. For lateral inhibition, we find that mutual inactivation speeds up patterning dynamics, relieves the need for cooperative regulatory interactions, and expands the range of parameter values that permit pattern formation, compared to canonical models. Furthermore, mutual inactivation enables a simple lateral inhibition circuit architecture which requires only a single downstream regulatory step. Both model systems show how mutual inactivation can facilitate robust fine-grained patterning processes that would be difficult to implement without it, by encoding a difference-promoting feedback within the signaling system itself. Together, these results provide a framework for analysis of more complex Notch-dependent developmental systems.

Ofd1 controls dorso-ventral patterning and axoneme elongation during embryonic brain development.

Directory of Open Access Journals (Sweden)

Anna D'Angelo

Full Text Available Oral-facial-digital type I syndrome (OFDI is a human X-linked dominant-male-lethal developmental disorder caused by mutations in the OFD1 gene. Similar to other inherited disorders associated to ciliary dysfunction OFD type I patients display neurological abnormalities. We characterized the neuronal phenotype that results from Ofd1 inactivation in early phases of mouse embryonic development and at post-natal stages. We determined that Ofd1 plays a crucial role in forebrain development, and in particular, in the control of dorso-ventral patterning and early corticogenesis. We observed abnormal activation of Sonic hedgehog (Shh, a major pathway modulating brain development. Ultrastructural studies demonstrated that early Ofd1 inactivation results in the absence of ciliary axonemes despite the presence of mature basal bodies that are correctly orientated and docked. Ofd1 inducible-mediated inactivation at birth does not affect ciliogenesis in the cortex, suggesting a developmental stage-dependent role for a basal body protein in ciliogenesis. Moreover, we showed defects in cytoskeletal organization and apical-basal polarity in Ofd1 mutant embryos, most likely due to lack of ciliary axonemes. Thus, the present study identifies Ofd1 as a developmental disease gene that is critical for forebrain development and ciliogenesis in embryonic life, and indicates that Ofd1 functions after docking and before elaboration of the axoneme in vivo.

Calcium imaging of basal forebrain activity during innate and learned behaviors

Directory of Open Access Journals (Sweden)

Thomas Clarke Harrison

2016-05-01

Full Text Available The basal forebrain (BF plays crucial roles in arousal, attention, and memory, and its impairment is associated with a variety of cognitive deficits. The BF consists of cholinergic, GABAergic, and glutamatergic neurons. Electrical or optogenetic stimulation of BF cholinergic neurons enhances cortical processing and behavioral performance, but the natural activity of these cells during behavior is only beginning to be characterized. Even less is known about GABAergic and glutamatergic neurons. Here, we performed microendoscopic calcium imaging of BF neurons as mice engaged in spontaneous behaviors in their home cages (innate or performed a go/no-go auditory discrimination task (learned. Cholinergic neurons were consistently excited during movement, including running and licking, but GABAergic and glutamatergic neurons exhibited diverse responses. All cell types were activated by overt punishment, either inside or outside of the discrimination task. These findings reveal functional similarities and distinctions between BF cell types during both spontaneous and task-related behaviors.

Desorption of Lipases Immobilized on Octyl-Agarose Beads and Coated with Ionic Polymers after Thermal Inactivation. Stronger Adsorption of Polymers/Unfolded Protein Composites

Directory of Open Access Journals (Sweden)

Jose J. Virgen-Ortíz

2017-01-01

Full Text Available Lipases from Candida antarctica (isoform B and Rhizomucor miehei (CALB and RML have been immobilized on octyl-agarose (OC and further coated with polyethylenimine (PEI and dextran sulfate (DS. The enzymes just immobilized on OC supports could be easily released from the support using 2% SDS at pH 7, both intact or after thermal inactivation (in fact, after inactivation most enzyme molecules were already desorbed. The coating with PEI and DS greatly reduced the enzyme release during thermal inactivation and improved enzyme stability. However, using OC-CALB/RML-PEI-DS, the full release of the immobilized enzyme to reuse the support required more drastic conditions: a pH value of 3, a buffer concentration over 2 M, and temperatures above 45 °C. However, even these conditions were not able to fully release the thermally inactivated enzyme molecules from the support, being necessary to increase the buffer concentration to 4 M sodium phosphate and decrease the pH to 2.5. The formation of unfolded protein/polymers composites seems to be responsible for this strong interaction between the octyl and some anionic groups of OC supports. The support could be reused five cycles using these conditions with similar loading capacity of the support and stability of the immobilized enzyme.

Chlorophyll mediated photodynamic inactivation of blue laser on Streptococcus mutans

Science.gov (United States)

Astuti, Suryani Dyah; Zaidan, A.; Setiawati, Ernie Maduratna; Suhariningsih

2016-03-01

Photodynamic inactivation is an inactivation method in microbial pathogens that utilize light and photosensitizer. This study was conducted to investigate photodynamic inactivation effects of low intensity laser exposure with various dose energy on Streptococcus mutans bacteria. The photodynamic inactivation was achieved with the addition of chlorophyll as photosensitizers. To determine the survival percentage of Streptococcus mutans bacteria after laser exposure, the total plate count method was used. For this study, the wavelength of the laser is 405 nm and variables of energy doses are 1.44, 2.87, 4.31, 5.74, 7.18, and 8.61 in J/cm2. The results show that exposure to laser with energy dose of 7.18 J/cm2 has the best photodynamic inactivation with a decrease of 78% in Streptococcus

Comparison of Giardia lamblia and Giardia muris cyst inactivation by ozone.

Science.gov (United States)

Finch, G R; Black, E K; Labatiuk, C W; Gyürék, L; Belosevic, M

1993-11-01

Inactivation of Giardia lamblia and Giardia muris cysts was compared by using an ozone demand-free 0.05 M phosphate buffer in bench-scale batch reactors at 22 degrees C. Ozone was added to each trial from a concentrated stock solution for contact times of 2 and 5 min. The viability of the control and treated cysts was evaluated by using the C3H/HeN mouse and Mongolian gerbil models for G. muris and G. lamblia, respectively. The resistance of G. lamblia to ozone was not significantly different from that of G. muris under the study conditions, contrary to previously reported data that suggested G. lamblia was significantly more sensitive to ozone than G. muris was. The simple Ct value for 2 log unit inactivation of G. lamblia was 2.4 times higher than the Ct value recommended by the Surface Water Treatment Rule.

Reduced brain perfusion in basal forebrain associated with cognitive decline in Alzheimer's diseases: a Tc-99m HMPAO SPECT study

International Nuclear Information System (INIS)

Lee, M.C.; Kang, H.; Kang, E.; Lee, J.S.; Lee, D.S.; Lee, D.W.; Cho, M.J.

2002-01-01

Aim: Reduction of regional cerebral blood flow (rCBF) in various cerebral regions and decline of cognitive function have been reported in Alzheimer's disease (AD) patients. The aim of this study was to identify the brain areas showing correlation between longitudinal changes of rCBFs and decline of general mental function, measured by Mini-Mental State Examination (MMSE) in probable Alzheimer's disease patients. Materials and Methods: Nine probable AD patients according to NINCDS-ADRDA criteria and DSM-IV were studied with Tc-99m HMPAO SPECT at an initial point and at the follow-up after a period of average 1.8 year. MMSE score was obtained in both occasions (average MMSE 16.4 at initial study; average MMSE = 8.1 at follow-up). Single SPECT was performed in 30 age-matched normal controls. Each SPECT image was normalized to the cerebellar activity. Using statistical parametric mapping (SPM99), correlation was analyzed between individual changes in rCBF of two SPECT scans and the MMSE scores at the time of each study in AD patients. In addition, the SPECT images of the initial study and the follow-up study were compared with SPECT images of the age-matched normal group respectively. Results: Significant correlation between longitudinal changes of rCBFs and MMSE scores was found in left basal forebrain region including substantia innominata (x, y, z = -24, 16, -23; P < .05, corrected). Within a short follow-up period of 1.8 years, cerebral hypoperfusion extended to various cortical regions from bilateral temporo-parietal to bilateral frontal regions and cingulate cortex, compared to normal controls. Conclusion: The decline of cognitive function in individual AD patients was correlated with rCBF reduction in left basal forebrain. This finding supports the cholinergic hypothesis of AD since hypoperfusion in basal forebrain region might indicate deterioration of cholinergic neurons in nucleus basalis of Meynert or substantia innominata

Inactivation of RNA Viruses by Gamma Irradiation: A Study on Mitigating Factors

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Adam J. Hume

2016-07-01

Full Text Available Effective inactivation of biosafety level 4 (BSL-4 pathogens is vital in order to study these agents safely. Gamma irradiation is a commonly used method for the inactivation of BSL-4 viruses, which among other advantages, facilitates the study of inactivated yet morphologically intact virions. The reported values for susceptibility of viruses to inactivation by gamma irradiation are sometimes inconsistent, likely due to differences in experimental protocols. We analyzed the effects of common sample attributes on the inactivation of a recombinant vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein and green fluorescent protein. Using this surrogate virus, we found that sample volume and protein content of the sample modulated viral inactivation by gamma irradiation but that air volume within the sample container and the addition of external disinfectant surrounding the sample did not. These data identify several factors which alter viral susceptibility to inactivation and highlight the usefulness of lower biosafety level surrogate viruses for such studies. Our results underscore the need to validate inactivation protocols of BSL-4 pathogens using “worst-case scenario” procedures to ensure complete sample inactivation.

X inactivation in females with X-linked Charcot-Marie-Tooth disease.

LENUS (Irish Health Repository)

Murphy, Sinéad M

2012-07-01

X-linked Charcot-Marie-Tooth disease (CMT1X) is the second most common inherited neuropathy, caused by mutations in gap junction beta-1 (GJB1). Males have a uniformly moderately severe phenotype while females have a variable phenotype, suggested to be due to X inactivation. We aimed to assess X inactivation pattern in females with CMT1X and correlate this with phenotype using the CMT examination score to determine whether the X inactivation pattern accounted for the variable phenotype in females with CMT1X. We determined X inactivation pattern in 67 females with CMT1X and 24 controls using the androgen receptor assay. We were able to determine which X chromosome carried the GJB1 mutation in 30 females. There was no difference in X inactivation pattern between patients and controls. In addition, there was no correlation between X inactivation pattern in blood and phenotype. A possible explanation for these findings is that the X inactivation pattern in Schwann cells rather than in blood may explain the variable phenotype in females with CMT1X.

Effect of ohmic heating of soymilk on urease inactivation and kinetic analysis in holding time.

Science.gov (United States)

Li, Fa-De; Chen, Chen; Ren, Jie; Wang, Ranran; Wu, Peng

2015-02-01

To verify the effect of the ohmic heating on the urease activity in the soymilk, the ohmic heating methods with the different electrical field conditions (the frequency and the voltage ranging from 50 to 10 kHz and from 160 to 220 V, respectively) were employed. The results showed that if the value of the urease activity measured with the quantitative spectrophotometry method was lower than 16.8 IU, the urease activity measured with the qualitative method was negative. The urease activity of the sample ohmically heated was significantly lower than that of the sample conventionally heated (P urease inactivation. In addition, the inactivation kinetics of the urease in the soymilk could be described with a biphasic model during holding time at a target temperature. Thus, it was concluded that the urease in the soymilk would contain 2 isoenzymes, one is the thermolabile fraction, the other the thermostable fraction, and that the thermostable isoenzyme could not be completely inactivated when the holding time increased, whether the soymilk was cooked with the conventional method or with the ohmic heating method. Therefore, the electric field had no effect on the inactivation of the thermostable isoenzyme of the urease. © 2015 Institute of Food Technologists®

The cerebroprotective effect of dextromethorphan assessed by 1H and 31P NMR spectroscopy during global forebrain ischemia in the rat

International Nuclear Information System (INIS)

Tulleken, C.A.F.; Rijen, P.C. van; Berkelbach van der Sprenkel, J.W.; Verheul, H.B.; Echteld, C.J.A. van; Balasz, R.; Lewis, P.

1991-01-01

Global forebrain ischemia was induced in the rat model by occlusion of both carotid arteries and subsequent lowering of the blood pressure. After 30 minutes of ischemia reperfusion was established. Using 1H and 31P NMR spectroscopy tissue pH values, lactate production, cellular energy index and N-acetyl-aspartate content were determined. The survival rates and histological damage were counted. (author)

Inactivation of prion infectivity by ionizing rays

Energy Technology Data Exchange (ETDEWEB)

Gominet, M. [Ionisos, ZI les Chatinieres, F01120 Dagneux (France); Vadrot, C.; Austruy, G. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France); Darbord, J.C. [Paris V University, Central Pharmacy of Hospitals, 4 avenue de l' Observatoire, F-75006, Paris (France)], E-mail: darbord@pharmacie.univ-paris5.fr

2007-11-15

Inactivation of prion deposits on medical devices or prion contamination in pharmaceutical raw materials is considered as impossible by using gamma irradiation. Early, the guideline WHO/CDS/CSR/APH/2000 has described irradiation as an ineffective process. But, in 2003, S. Miekka et al. noted radiation inactivation of prions in a particular application to purify human albumin, shown by the physical denaturation of the infectious protein (PrP). The aim of our study was to determine the inactivation of prions with a scrapie model (strain C506M3) by irradiating standardised preparations. Results: Gamma irradiation was partially effective, showing a 4-5 log reduction on exposure to 50 kGy. A characteristic effect-dose curve was not observed (25, 50 and 100 kGy), only an increase in the incubation period of the murine disease (229 days with 25 kGy to 290 days with 100 kGy) compared with 170 days without irradiation. Since the inactivation was not a total one, the observed effect is significant. It is proposed that further work be undertaken with the model to investigate the application of gamma radiation known levels of prion contamination.

Inactivation of prion infectivity by ionizing rays

International Nuclear Information System (INIS)

Gominet, M.; Vadrot, C.; Austruy, G.; Darbord, J.C.

2007-01-01

Inactivation of prion deposits on medical devices or prion contamination in pharmaceutical raw materials is considered as impossible by using gamma irradiation. Early, the guideline WHO/CDS/CSR/APH/2000 has described irradiation as an ineffective process. But, in 2003, S. Miekka et al. noted radiation inactivation of prions in a particular application to purify human albumin, shown by the physical denaturation of the infectious protein (PrP). The aim of our study was to determine the inactivation of prions with a scrapie model (strain C506M3) by irradiating standardised preparations. Results: Gamma irradiation was partially effective, showing a 4-5 log reduction on exposure to 50 kGy. A characteristic effect-dose curve was not observed (25, 50 and 100 kGy), only an increase in the incubation period of the murine disease (229 days with 25 kGy to 290 days with 100 kGy) compared with 170 days without irradiation. Since the inactivation was not a total one, the observed effect is significant. It is proposed that further work be undertaken with the model to investigate the application of gamma radiation known levels of prion contamination

Thermal and high pressure inactivation kinetics of blueberry peroxidase.

Science.gov (United States)

Terefe, Netsanet Shiferaw; Delon, Antoine; Versteeg, Cornelis

2017-10-01

This study for the first time investigated the stability and inactivation kinetics of blueberry peroxidase in model systems (McIlvaine buffer, pH=3.6, the typical pH of blueberry juice) during thermal (40-80°C) and combined high pressure-thermal processing (0.1-690MPa, 30-90°C). At 70-80°C, the thermal inactivation kinetics was best described by a biphasic model with ∼61% labile and ∼39% stable fractions at temperature between 70 and 75°C. High pressure inhibited the inactivation of the enzyme with no inactivation at pressures as high as 690MPa and temperatures less than 50°C. The inactivation kinetics of the enzyme at 60-70°C, and pressures higher than 500MPa was best described by a first order biphasic model with ∼25% labile fraction and 75% stable fraction. The activation energy values at atmospheric pressure were 548.6kJ/mol and 324.5kJ/mol respectively for the stable and the labile fractions. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Evaluation of the treatment of both sides of raw chicken breasts with an atmospheric pressure plasma jet for the inactivation of Escherichia coli.

Science.gov (United States)

Yong, Hae In; Kim, Hyun-Joo; Park, Sanghoo; Choe, Wonho; Oh, Mi Wha; Jo, Cheorun

2014-08-01

Atmospheric pressure plasma (APP) is an emerging nonthermal microbial inactivation technique. In this study, agar and raw chicken breast were inoculated with Escherichia coli and treated with an APP jet based on cold arc plasma. The aim of this study was to investigate the optimum conditions for the plasma treatment of an APP jet in order to maximize the efficiency of E. coli inactivation. The combination of N2+O2 (10 standard cubic centimeters per minute) and a longer treatment time (10 min) resulted in the highest inactivation of E. coli on agar plates with an optimum treatment distance of 20 mm. The samples in dry and wet conditions showed similar reductions in E. coli count when one side of the samples was treated at a given treatment time. Treating both sides-2.5 min on each side-resulted in a higher growth inhibition of E. coli than treatment of a single side only for 5 min. However, there was no significant difference between one-side treated samples (10 min) and both-sides treated samples (5+5 min). When the concentration of E. coli in the chicken breast sample was 10(4) colony-forming units (CFU)/g, the reduction rate of the E. coli was the highest, followed by 10(5), 10(6), and 10(7) CFU/g; however, no difference was found between 10(3) and 10(4) CFU/g. In conclusion, various treatment conditions may affect the inactivation efficiency of E. coli. In the present study, the optimum condition was determined as the treatment distance of 20 mm and longer treatment time (10 min) with the addition of oxygen to the nitrogen gas flow. Furthermore, the cell concentration of sample was an important parameter for the efficacy of the inactivation process.

Thermal inactivation kinetics of β-galactosidase during bread baking.

Science.gov (United States)

Zhang, Lu; Chen, Xiao Dong; Boom, Remko M; Schutyser, Maarten A I

2017-06-15

In this study, β-galactosidase was utilized as a model enzyme to investigate the mechanism of enzyme inactivation during bread baking. Thermal inactivation of β-galactosidase was investigated in a wheat flour/water system at varying temperature-moisture content combinations, and in bread during baking at 175 or 205°C. In the wheat flour/water system, the thermostability of β-galactosidase increased with decreased moisture content, and a kinetic model was accurately fitted to the corresponding inactivation data (R 2 =0.99). Interestingly, the residual enzyme activity in the bread crust (about 30%) was hundredfold higher than that in the crumb (about 0.3%) after baking, despite the higher temperature in the crust throughout baking. This result suggested that the reduced moisture content in the crust increased the thermostability of the enzyme. Subsequently, the kinetic model reasonably predicted the enzyme inactivation in the crumb using the same parameters derived from the wheat flour/water system. However, the model predicted a lower residual enzyme activity in the crust compared with the experimental result, which indicated that the structure of the crust may influence the enzyme inactivation mechanism during baking. The results reported can provide a quantitative understanding of the thermal inactivation kinetics of enzyme during baking, which is essential to better retain enzymatic activity in bakery products supplemented with heat-sensitive enzymes. Copyright © 2017 Elsevier Ltd. All rights reserved.

How microelectrode array-based chick forebrain neuron biosensors respond to glutamate NMDA receptor antagonist AP5 and GABAA receptor antagonist musimol

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Serena Y. Kuang

2016-09-01

Full Text Available We have established a long-term, stable primary chick forebrain neuron (FBN culture on a microelectrode array platform as a biosensor system for neurotoxicant screening and for neuroelectrophysiological studies for multiple purposes. This paper reports some of our results, which characterize the biosensor pharmacologically. Dose-response experiments were conducted using NMDA receptor antagonist AP5 and GABAA receptor agonist musimol (MUS. The chick FBN biosensor (C-FBN-biosensor responds to the two agents in a pattern similar to that of rodent counterparts; the estimated EC50s (the effective concentration that causes 50% inhibition of the maximal effect are 2.3 μM and 0.25 μM, respectively. Intercultural and intracultural reproducibility and long-term reusability of the C-FBN-biosensor are addressed and discussed. A phenomenon of sensitization of the biosensor that accompanies intracultural reproducibility in paired dose-response experiments for the same agent (AP5 or MUS is reported. The potential application of the C-FBN-biosensor as an alternative to rodent biosensors in shared sensing domains (NMDA receptor and GABAA receptor is suggested. Keywords: Biosensor, Microelectrode array, Neurotoxicity, Chick forebrain neuron, AP5, Musimol

Production of DNA strand breaks by ionizing radiation of different quality and their consequences for cell inactivation

International Nuclear Information System (INIS)

Kampf, G.

1983-07-01

The production of single- and double-strand breaks (DSB) in the DNA of Chinese hamster cells (V 79) was studied by use of 11 radiation qualities, with some also under hypoxic conditions. The aim was to find relations between the induction of lesions on the molecular level and the expression of this damage on the cellular level. The results suggest that release of DNA from the nuclear-membrane complex, induction of chromosome breaks, and cell inactivation are triggered by DSB. However, not simply a certain number of DSB in the DNA of the nucleus, but their cooperation within a small structural section of DNA is required for cell inactivation. Such sections may be the membrane-associated superstructure units. DSB produced under hypoxic conditions show a greater effectiveness than those produced under oxic conditions. The investigations with eukaryotic cells and bacteria suggest that not the entire DNA of all organisms but a structural unit common to them represents the critical target for radiation action. (author)

Direct generation of titanium dioxide nanoparticles dispersion under supercritical conditions for photocatalytic active thermoplastic surfaces for microbiological inactivation

International Nuclear Information System (INIS)

Zydziak, Nicolas; Zanin, Maria-Helena Ambrosio; Trick, Iris; Hübner, Christof

2015-01-01

Thermoplastic poly(propylene) (PP) and acrylonitrile-butadiene-styrene (ABS) surfaces were coated with silica based films via the sol–gel process, containing titanium dioxide (TiO 2 ) as photocatalyst. TiO 2 was previously synthesized via sol–gel and treated under supercritical conditions in water dispersions. The characterization of the TiO 2 dispersions was performed via disc centrifuge to determine the particle size and via Raman spectroscopy and X-Ray Diffraction (XRD) to characterize the crystallinity of TiO 2 . The synthesized TiO 2 dispersions and commercially available TiO 2 particles were incorporated in silica based films which were synthesized under acidic or basic conditions, leading to dense or porous films respectively. The morphology of the films was characterized via Scanning Electron Microscopy (SEM). The incorporation of synthesized TiO 2 in the coating led to photocatalytically more active thermoplastic surfaces than films formulated with commercially available TiO 2 as determined via dye discoloration test. A microbiological test performed with Sarcina lutea confirmed this result and showed an inactivation factor of 6 (99.9999%) after 24 h UV irradiation, for synthesized TiO 2 incorporated in acidic formulated silica layer on ABS surfaces. - Highlights: • We report about photocatalytic layers formulated on thermoplastic surfaces. • We synthesized silica layer and TiO 2 via sol–gel and supercritical treatment. • Amorphous, crystalline and commercial dispersions were generated and characterized. • The morphology of dense and porous photocatalytic layers is observed via SEM. • Discoloration and microbiological tests correlate activity and surface morphology

Thermal inactivation of enzymes and pathogens in biosamples for MS analysis.

Science.gov (United States)

Ahnoff, Martin; Cazares, Lisa H; Sköld, Karl

2015-01-01

Protein denaturation is the common basis for enzyme inactivation and inactivation of pathogens, necessary for preservation and safe handling of biosamples for downstream analysis. While heat-stabilization technology has been used in proteomic and peptidomic research since its introduction in 2009, the advantages of using the technique for simultaneous pathogen inactivation have only recently been addressed. The time required for enzyme inactivation by heat (≈1 min) is short compared with chemical treatments, and inactivation is irreversible in contrast to freezing. Heat stabilization thus facilitates mass spectrometric studies of biomolecules with a fast conversion rate, and expands the chemical space of potential biomarkers to include more short-lived entities, such as phosphorylated proteins, in tissue samples as well as whole-blood (dried blood sample) samples.

Trehalose and sorbitol alter the kinetic pattern of inactivation of glutamate dehydrogenase during drying in levitated microdroplets.

Science.gov (United States)

Lorenzen, Elke; Lee, Geoffrey

2013-12-01

A single-droplet acoustic levitator was used to determine the drying rate and the kinetics of inactivation of glutamate dehydrogenase in the presence of added trehalose or sorbitol. The solution was also spray dried under the same process condition of drying gas temperature on a bench-top machine. Both trehalose and sorbitol delay the point of onset of enzyme inactivation which lies after the critical point of drying. Both carbohydrates also reduce the apparent rate constant of inactivation calculated during the subsequent inactivation phase. The carbohydrates stabilise, therefore, the enzyme during droplet drying and particle formation mainly during the falling rate drying period. There is no difference between the stabilising effects of the two carbohydrates when examined as levitated single droplets. This suggests the importance of water replacement as a stabilising mechanism in the levitated droplets/particles. On spray drying, the trehalose stabilises the enzyme better than does the sorbitol at a drying gas (outlet) temperature of 60°C. This suggests glass formation with the trehalose but not the sorbitol during the very rapid drying process of small-atomised droplets in the spray dryer. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

Cortical inactivation by cooling in small animals

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Ben eCoomber

2011-06-01

Full Text Available Reversible inactivation of the cortex by surface cooling is a powerful method for studying the function of a particular area. Implanted cooling cryoloops have been used to study the role of individual cortical areas in auditory processing of awake-behaving cats. Cryoloops have also been used in rodents for reversible inactivation of the cortex, but recently there has been a concern that the cryoloop may also cool non-cortical structures either directly or via the perfusion of blood, cooled as it passed close to the cooling loop. In this study we have confirmed that the loop can inactivate most of the auditory cortex without causing a significant reduction in temperature of the auditory thalamus or other sub-cortical structures. We placed a cryoloop on the surface of the guinea pig cortex, cooled it to 2°C and measured thermal gradients across the neocortical surface. We found that the temperature dropped to 20-24°C among cells within a radius of about 2.5mm away from the loop. This temperature drop was sufficient to reduce activity of most cortical cells and led to the inactivation of almost the entire auditory region. When the temperature of thalamus, midbrain, and middle ear were measured directly during cortical cooling, there was a small drop in temperature (about 4°C but this was not sufficient to directly reduce neural activity. In an effort to visualise the extent of neural inactivation we measured the uptake of thallium ions following an intravenous injection. This confirmed that there was a large reduction of activity across much of the ipsilateral cortex and only a small reduction in subcortical structures.

Eslicarbazepine and the enhancement of slow inactivation of voltage-gated sodium channels: a comparison with carbamazepine, oxcarbazepine and lacosamide.

Science.gov (United States)

Hebeisen, Simon; Pires, Nuno; Loureiro, Ana I; Bonifácio, Maria João; Palma, Nuno; Whyment, Andrew; Spanswick, David; Soares-da-Silva, Patrício

2015-02-01

This study aimed at evaluating the effects of eslicarbazepine, carbamazepine (CBZ), oxcarbazepine (OXC) and lacosamide (LCM) on the fast and slow inactivated states of voltage-gated sodium channels (VGSC). The anti-epileptiform activity was evaluated in mouse isolated hippocampal slices. The anticonvulsant effects were evaluated in MES and the 6-Hz psychomotor tests. The whole-cell patch-clamp technique was used to investigate the effects of eslicarbazepine, CBZ, OXC and LCM on sodium channels endogenously expressed in N1E-115 mouse neuroblastoma cells. CBZ and eslicarbazepine exhibit similar concentration dependent suppression of epileptiform activity in hippocampal slices. In N1E-115 mouse neuroblastoma cells, at a concentration of 250 μM, the voltage dependence of the fast inactivation was not influenced by eslicarbazepine, whereas LCM, CBZ and OXC shifted the V0.5 value (mV) by -4.8, -12.0 and -16.6, respectively. Eslicarbazepine- and LCM-treated fast-inactivated channels recovered similarly to control conditions, whereas CBZ- and OXC-treated channels required longer pulses to recover. CBZ, eslicarbazepine and LCM shifted the voltage dependence of the slow inactivation (V0.5, mV) by -4.6, -31.2 and -53.3, respectively. For eslicarbazepine, LCM, CBZ and OXC, the affinity to the slow inactivated state was 5.9, 10.4, 1.7 and 1.8 times higher than to the channels in the resting state, respectively. In conclusion, eslicarbazepine did not share with CBZ and OXC the ability to alter fast inactivation of VGSC. Both eslicarbazepine and LCM reduce VGSC availability through enhancement of slow inactivation, but LCM demonstrated higher interaction with VGSC in the resting state and with fast inactivation gating. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inactivation as a new regulatory mechanism for neuronal Kv7 channels

DEFF Research Database (Denmark)

Jensen, Henrik Sindal; Grunnet, Morten; Olesen, Søren-Peter

2007-01-01

neuronal channels and are important for controlling excitability. Kv7.1 channels have been considered the only Kv7 channels to undergo inactivation upon depolarization. However, here we demonstrate that inactivation is also an intrinsic property of Kv7.4 and Kv7.5 channels, which inactivate to a larger...

Quantum chromodynamics as the sequential fragmenting with inactivation

International Nuclear Information System (INIS)

Botet, R.

1996-01-01

We investigate the relation between the modified leading log approximation of the perturbative QCD and the sequential binary fragmentation process. We will show that in the absence of inactivation, this process is equivalent to the QCD gluodynamics. The inactivation term yields a precise prescription of how to include the hadronization in the QCD equations. (authors)

Scale down of the inactivated polio vaccine production process

NARCIS (Netherlands)

Thomassen, Y.E.; Oever, van 't R.; Vinke, C.M.; Spiekstra, A.; Wijffels, R.H.; Pol, van der L.A.; Bakker, W.A.M.

2013-01-01

The anticipated increase in the demand for inactivated polio vaccines resulting from the success in the polio eradication program requires an increase in production capacity and cost price reduction of the current inactivated polio vaccine production processes. Improvement of existing production

Saturation of SERCA's lipid annulus may protect against its thermal inactivation

International Nuclear Information System (INIS)

Fajardo, Val Andrew; Trojanowski, Natalie; Castelli, Laura M.; Miotto, Paula M.; Amoye, Foyinsola; Ward, Wendy E.; Tupling, A. Russell; LeBlanc, Paul J.

2017-01-01

The sarco(endo)plasmic reticulum Ca 2+ -ATPase (SERCA) pumps are integral membrane proteins that catalyze the active transport of Ca 2+ into the sarcoplasmic reticulum, thereby eliciting muscle relaxation. SERCA pumps are highly susceptible to oxidative damage, and cytoprotection of SERCA dampens thermal inactivation and is a viable therapeutic strategy in combating diseases where SERCA activity is impaired, such as muscular dystrophy. Here, we sought to determine whether increasing the percent of saturated fatty acids (SFA) within SERCA's lipid annulus through diet could protect SERCA pumps from thermal inactivation. Female Wistar rats were fed either a semi-purified control diet (AIN93G, 7% soybean oil by weight) or a modified AIN93G diet containing high SFA (20% lard by weight) for 17 weeks. Soleus muscles were extracted and SERCA lipid annulus and activity under thermal stress were analyzed. Our results show that SERCA's lipid annulus is abundant with short-chain (12–14 carbon) fatty acids, which corresponds well with SERCA's predicted bilayer thickness of 21 Å. Under control-fed conditions, SERCA's lipid annulus was already highly saturated (79%), and high-fat feeding did not increase this any further. High-fat feeding did not mitigate the reductions in SERCA activity seen with thermal stress; however, correlational analyses revealed significant and strong associations between % SFA and thermal stability of SERCA activity with greater %SFA being associated with lower thermal inactivation and greater % polyunsaturation and unsaturation index being associated with increased thermal inactivation. Altogether, these findings show that SERCA's lipid annulus may influence its susceptibility to oxidative damage, which could have implications in muscular dystrophy and age-related muscle wasting. - Highlights: • SERCA's lipid annulus in rat soleus was measured after immunoconcentration. • Short fatty acid chains surround SERCA and

Cytolytic T lymphocyte responses to metabolically inactivated stimulator cells. I. Metabolic inactivation impairs both CD and LD antigen signals

International Nuclear Information System (INIS)

Kelso, A.; Boyle, W.

1982-01-01

The effects of metabolic inactivation of spleen cells on antigen presentation to precursors of alloreactive cytolytic T lymphocytes (T/sub c/) were examined. By serological methods, populations inactivated by ultraviolet irradiation, glutaraldehyde fixation or plasma membrane isolation were found to retain normal levels of H-2K/D and Ia antigens. However, comparison of the antigen doses required to stimulate secondary T/sub c/ responses in mixed leukocyte culture showed that the inactivated preparations were approximately 10-fold less immunogenic than X-irradiated spleen cells. Their total inability to stimulate primary cytolytic responses pointed to at least a 100-fold impairment of immunogenicity for unprimed T/sub c/ precursors in the case of uv-irradiated and glutaraldehyde-treated stimulator cells, and at least a 10-fold impairment for membrane fragments. Experiments showing that the capacity of cell monolayers to absorb precursor T/sub c/ from unprimed spleen populations was reduced following uv-irradiation or glutaraldehyde treatment provided direct evidence that this loss of immunogenicity was due in part to suboptimal antigen presentation to precursor T/sub c/. It is concluded that, in addition to the traditional view that these treatments damage the ''LD'' signal to helper T lymphocytes, metabolic inactivation also impairs recognition of ''CD'' determinants by precursor T/sub c/

Quantum chromodynamics as the sequential fragmenting with inactivation

Energy Technology Data Exchange (ETDEWEB)

Botet, R. [Paris-11 Univ., 91 - Orsay (France). Lab. de Physique des Solides; Ploszajczak, M. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France)

1996-12-31

We investigate the relation between the modified leading log approximation of the perturbative QCD and the sequential binary fragmentation process. We will show that in the absence of inactivation, this process is equivalent to the QCD gluodynamics. The inactivation term yields a precise prescription of how to include the hadronization in the QCD equations. (authors). 15 refs.

Characterization of the functional domains of the natriuretic peptide receptor/guanylate cyclase by radiation inactivation

International Nuclear Information System (INIS)

Tremblay, J.; Huot, C.; Koch, C.; Potier, M.

1991-01-01

Radiation inactivation has been used to evaluate the molecular size of domains responsible for atrial natriuretic peptide (ANP)-binding and cyclase functions of the ANP receptor/guanylate cyclase. Two types of inactivation curves were observed for cyclase function in both adrenal cortex and aortic smooth muscle cells: (1) biphasic with enhanced guanylate cyclase activity after exposure to low radiation doses and (2) linear after preincubation of membrane proteins with 0.5 microM ANP or solubilization with Triton X-100. The existence of an inhibitory component was the simplest model that best explained the types of radiation curves obtained. Activation of guanylate cyclase by ANP or Triton X-100 could occur via the dissociation of this inhibitory component from the catalytic domain. On the other hand, the loss of ANP-binding activity was linear with increasing radiation exposures under basal, ANP treatment, and Triton X-100 solubilization conditions. Radiation inactivation sizes of about 30 kDa for cyclase function, 20 kDa for ANP-binding function, and 90 kDa for inhibitory function were calculated. These studies suggest that the ANP receptor/guanylate cyclase behaves as a multidomain protein. The results obtained by radiation inactivation of the various biological functions of this receptor are compatible with the hypothesis of an intramolecular inhibitory domain repressing the guanylate cyclase catalytic domain within its membrane environment

The assessment of efficacy of porcine reproductive respiratory syndrome virus inactivated vaccine based on the viral quantity and inactivation methods

Directory of Open Access Journals (Sweden)

Lee Byeongchun

2011-06-01

Full Text Available Abstract Background There have been many efforts to develop efficient vaccines for the control of porcine reproductive and respiratory syndrome virus (PRRSV. Although inactivated PRRSV vaccines are preferred for their safety, they are weak at inducing humoral immune responses and controlling field PRRSV infection, especially when heterologous viruses are involved. Results In all groups, the sample to positive (S/P ratio of IDEXX ELISA and the virus neutralization (VN titer remained negative until challenge. While viremia did not reduce in the vaccinated groups, the IDEXX-ELISA-specific immunoglobulin G increased more rapidly and to significantly greater levels 7 days after the challenge in all the vaccinated groups compared to the non-vaccinated groups (p 6 PFU/mL PRRSV vaccine-inoculated and binary ethylenimine (BEI-inactivated groups 22 days after challenge (p Conclusions The inactivated vaccine failed to show the humoral immunity, but it showed different immune response after the challenge compared to mock group. Although the 106 PFU/mL-vaccinated and BEI-inactivated groups showed significantly greater VN titers 22 days after challenge, all the groups were already negative for viremia.

Spontaneous sleep-wake cycle and sleep deprivation differently induce Bdnf1, Bdnf4 and Bdnf9a DNA methylation and transcripts levels in the basal forebrain and frontal cortex in rats.

Science.gov (United States)

Ventskovska, Olena; Porkka-Heiskanen, Tarja; Karpova, Nina N

2015-04-01

Brain-derived neurotrophic factor (Bdnf) regulates neuronal plasticity, slow wave activity and sleep homeostasis. Environmental stimuli control Bdnf expression through epigenetic mechanisms, but there are no data on epigenetic regulation of Bdnf by sleep or sleep deprivation. Here we investigated whether 5-methylcytosine (5mC) DNA modification at Bdnf promoters p1, p4 and p9 influences Bdnf1, Bdnf4 and Bdnf9a expression during the normal inactive phase or after sleep deprivation (SD) (3, 6 and 12 h, end-times being ZT3, ZT6 and ZT12) in rats in two brain areas involved in sleep regulation, the basal forebrain and cortex. We found a daytime variation in cortical Bdnf expression: Bdnf1 expression was highest at ZT6 and Bdnf4 lowest at ZT12. Such variation was not observed in the basal forebrain. Also Bdnf p1 and p9 methylation levels differed only in the cortex, while Bdnf p4 methylation did not vary in either area. Factorial analysis revealed that sleep deprivation significantly induced Bdnf1 and Bdnf4 with the similar pattern for Bdnf9a in both basal forebrain and cortex; 12 h of sleep deprivation decreased 5mC levels at the cortical Bdnf p4 and p9. Regression analysis between the 5mC promoter levels and the corresponding Bdnf transcript expression revealed significant negative correlations for the basal forebrain Bdnf1 and cortical Bdnf9a transcripts in only non-deprived rats, while these correlations were lost after sleep deprivation. Our results suggest that Bdnf transcription during the light phase of undisturbed sleep-wake cycle but not after SD is regulated at least partially by brain site-specific DNA methylation. © 2014 European Sleep Research Society.

The roles of the various plasma agents in the inactivation of bacteria

International Nuclear Information System (INIS)

Lu Xinpei; Xiong Qing; Tang Zhiyuan; Xiong Zhilan; Hu Jing; Jiang Zhonghe; Pan Yuan; Ye Tao; Cao Yingguang; Sun Ziyong

2008-01-01

The roles of various plasma agents in the inactivation of bacteria have recently been investigated. However, up to now, the effect of the charged particles on the inactivation of bacteria is not well understood. In this paper, an atmospheric pressure plasma jet device, which generates a cold plasma plume carrying a peak current of 300 mA, is used to investigate the role of the charged particles in the inactivation process. It is found that the charged particles play a minor role in the inactivation process when He/N 2 (3%) is used as working gas. On the other hand, when He/O 2 (3%) is used, the charged particles are expected to play an important role in the inactivation of bacteria. Further analysis shows that the negative ions O 2 - might be the charged particles that are playing the role. Besides, it is found that the active species, including O, O 3 , and metastable state O 2 *, can play a crucial role in the inactivation of the bacteria. However, the excited He*, N 2 C 3 Π u , and N 2 + B 2 Σ u + have no significant direct effect on the inactivation of bacteria. It is also concluded that heat and UV play no or minor role in the inactivation process

Properties of an intermediate-duration inactivation process of the voltage-gated sodium conductance in rat hippocampal CA1 neurons.

Science.gov (United States)

French, Christopher R; Zeng, Zhen; Williams, David A; Hill-Yardin, Elisa L; O'Brien, Terence J

2016-02-01

Rapid transmembrane flow of sodium ions produces the depolarizing phase of action potentials (APs) in most excitable tissue through voltage-gated sodium channels (NaV). Macroscopic currents display rapid activation followed by fast inactivation (IF) within milliseconds. Slow inactivation (IS) has been subsequently observed in several preparations including neuronal tissues. IS serves important physiological functions, but the kinetic properties are incompletely characterized, especially the operative timescales. Here we present evidence for an "intermediate inactivation" (II) process in rat hippocampal CA1 neurons with time constants of the order of 100 ms. The half-inactivation potentials (V0.5) of steady-state inactivation curves were hyperpolarized by increasing conditioning pulse duration from 50 to 500 ms and could be described by a sum of Boltzmann relations. II state transitions were observed after opening as well as subthreshold potentials. Entry into II after opening was relatively insensitive to membrane potential, and recovery of II became more rapid at hyperpolarized potentials. Removal of fast inactivation with cytoplasmic papaine revealed time constants of INa decay corresponding to II and IS with long depolarizations. Dynamic clamp revealed attenuation of trains of APs over the 10(2)-ms timescale, suggesting a functional role of II in repetitive firing accommodation. These experimental findings could be reproduced with a five-state Markov model. It is likely that II affects important aspects of hippocampal neuron response and may provide a drug target for sodium channel modulation. Copyright © 2016 the American Physiological Society.

Quantitative analysis of wet-heat inactivation in bovine spongiform encephalopathy

International Nuclear Information System (INIS)

Matsuura, Yuichi; Ishikawa, Yukiko; Bo, Xiao; Murayama, Yuichi; Yokoyama, Takashi; Somerville, Robert A.; Kitamoto, Tetsuyuki; Mohri, Shirou

2013-01-01

Highlights: ► We quantitatively analyzed wet-heat inactivation of the BSE agent. ► Infectivity of the BSE macerate did not survive 155 °C wet-heat treatment. ► Once the sample was dehydrated, infectivity was observed even at 170 °C. ► A quantitative PMCA assay was used to evaluate the degree of BSE inactivation. - Abstract: The bovine spongiform encephalopathy (BSE) agent is resistant to conventional microbial inactivation procedures and thus threatens the safety of cattle products and by-products. To obtain information necessary to assess BSE inactivation, we performed quantitative analysis of wet-heat inactivation of infectivity in BSE-infected cattle spinal cords. Using a highly sensitive bioassay, we found that infectivity in BSE cattle macerates fell with increase in temperatures from 133 °C to 150 °C and was not detected in the samples subjected to temperatures above 155 °C. In dry cattle tissues, infectivity was detected even at 170 °C. Thus, BSE infectivity reduces with increase in wet-heat temperatures but is less affected when tissues are dehydrated prior to the wet-heat treatment. The results of the quantitative protein misfolding cyclic amplification assay also demonstrated that the level of the protease-resistant prion protein fell below the bioassay detection limit by wet-heat at 155 °C and higher and could help assess BSE inactivation. Our results show that BSE infectivity is strongly resistant to wet-heat inactivation and that it is necessary to pay attention to BSE decontamination in recycled cattle by-products

Quantitative analysis of wet-heat inactivation in bovine spongiform encephalopathy

Energy Technology Data Exchange (ETDEWEB)

Matsuura, Yuichi; Ishikawa, Yukiko; Bo, Xiao; Murayama, Yuichi; Yokoyama, Takashi [Prion Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 (Japan); Somerville, Robert A. [The Roslin Institute and Royal (Dick) School of Veterinary Studies, Roslin, Midlothian, EH25 9PS (United Kingdom); Kitamoto, Tetsuyuki [Division of CJD Science and Technology, Department of Prion Research, Center for Translational and Advanced Animal Research on Human Diseases, Tohoku University Graduate School of Medicine, 2-1 Seiryo, Aoba, Sendai 980-8575 (Japan); Mohri, Shirou, E-mail: shirou@affrc.go.jp [Prion Disease Research Center, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 (Japan)

2013-03-01

Highlights: ► We quantitatively analyzed wet-heat inactivation of the BSE agent. ► Infectivity of the BSE macerate did not survive 155 °C wet-heat treatment. ► Once the sample was dehydrated, infectivity was observed even at 170 °C. ► A quantitative PMCA assay was used to evaluate the degree of BSE inactivation. - Abstract: The bovine spongiform encephalopathy (BSE) agent is resistant to conventional microbial inactivation procedures and thus threatens the safety of cattle products and by-products. To obtain information necessary to assess BSE inactivation, we performed quantitative analysis of wet-heat inactivation of infectivity in BSE-infected cattle spinal cords. Using a highly sensitive bioassay, we found that infectivity in BSE cattle macerates fell with increase in temperatures from 133 °C to 150 °C and was not detected in the samples subjected to temperatures above 155 °C. In dry cattle tissues, infectivity was detected even at 170 °C. Thus, BSE infectivity reduces with increase in wet-heat temperatures but is less affected when tissues are dehydrated prior to the wet-heat treatment. The results of the quantitative protein misfolding cyclic amplification assay also demonstrated that the level of the protease-resistant prion protein fell below the bioassay detection limit by wet-heat at 155 °C and higher and could help assess BSE inactivation. Our results show that BSE infectivity is strongly resistant to wet-heat inactivation and that it is necessary to pay attention to BSE decontamination in recycled cattle by-products.

THE ANTIGENIC POTENCY OF EPIDEMIC INFLUENZA VIRUS FOLLOWING INACTIVATION BY ULTRAVIOLET RADIATION

Science.gov (United States)

Salk, Jonas E.; Lavin, G. I.; Francis, Thomas

1940-01-01

A study of the antigenic potency of influenza virus inactivated by ultraviolet radiation has been made. Virus so inactivated is still capable of functioning as an immunizing agent when given to mice by the intraperitoneal route. In high concentrations inactivated virus appears to be nearly as effective as active virus but when quantitative comparisons of the immunity induced by different dilutions are made, it is seen that a hundredfold loss in immunizing capacity occurs during inactivation. Virus in suspensions prepared from the lungs of infected mice is inactivated more rapidly than virus in tissue culture medium. A standard for the comparison of vaccines of epidemic influenza virus is proposed. PMID:19871057

FMRP acts as a key messenger for dopamine modulation in the forebrain.

Science.gov (United States)

Wang, Hansen; Wu, Long-Jun; Kim, Susan S; Lee, Frank J S; Gong, Bo; Toyoda, Hiroki; Ren, Ming; Shang, Yu-Ze; Xu, Hui; Liu, Fang; Zhao, Ming-Gao; Zhuo, Min

2008-08-28

The fragile X mental retardation protein (FMRP) is an RNA-binding protein that controls translational efficiency and regulates synaptic plasticity. Here, we report that FMRP is involved in dopamine (DA) modulation of synaptic potentiation. AMPA glutamate receptor subtype 1 (GluR1) surface expression and phosphorylation in response to D1 receptor stimulation were reduced in cultured Fmr1(-/-) prefrontal cortex (PFC) neurons. Furthermore, D1 receptor signaling was impaired, accompanied by D1 receptor hyperphosphorylation at serine sites and subcellular redistribution of G protein-coupled receptor kinase 2 (GRK2) in both PFC and striatum of Fmr1(-/-) mice. FMRP interacted with GRK2, and pharmacological inhibition of GRK2 rescued D1 receptor signaling in Fmr1(-/-) neurons. Finally, D1 receptor agonist partially rescued hyperactivity and enhanced the motor function of Fmr1(-/-) mice. Our study has identified FMRP as a key messenger for DA modulation in the forebrain and may provide insights into the cellular and molecular mechanisms underlying fragile X syndrome.

Bacterial contamination of platelet concentrates: pathogen detection and inactivation methods

Directory of Open Access Journals (Sweden)

Dana Védy

2009-04-01

Full Text Available Whereas the reduction of transfusion related viral transmission has been a priority during the last decade, bacterial infection transmitted by transfusion still remains associated to a high morbidity and mortality, and constitutes the most frequent infectious risk of transfusion. This problem especially concerns platelet concentrates because of their favorable bacterial growth conditions. This review gives an overview of platelet transfusion-related bacterial contamination as well as on the different strategies to reduce this problem by using either bacterial detection or inactivation methods.

Fullerene C60 and graphene photosensibiles for photodynamic virus inactivation

Science.gov (United States)

Belousova, I.; Hvorostovsky, A.; Kiselev, V.; Zarubaev, V.; Kiselev, O.; Piotrovsky, L.; Anfimov, P.; Krisko, T.; Muraviova, T.; Rylkov, V.; Starodubzev, A.; Sirotkin, A.; Grishkanich, A.; Kudashev, I.; Kancer, A.; Kustikova, M.; Bykovskaya, E.; Mayurova, A.; Stupnikov, A.; Ruzankina, J.; Afanasyev, M.; Lukyanov, N.; Redka, D.; Paklinov, N.

2018-02-01

A solid-phase photosensitizer based on aggregated C60 fullerene and graphene oxide for photodynamic inactivation of pathogens in biological fluids was studied. The most promising technologies of inactivation include the photodynamic effect, which consists in the inactivation of infectious agents by active oxygen forms (including singlet oxygen), formed when light is activated by the photosensitizer introduced into the plasma. Research shows features of solid-phase systems based on graphene and fullerene C60 oxide, which is a combination of an effective inactivating pathogens (for example, influenza viruses) reactive oxygen species formed upon irradiation of the photosensitizer in aqueous and biological fluids, a high photostability fullerene coatings and the possibility of full recovery photosensitizer from the biological environment after the photodynamic action.

Thermal inactivation kinetics of β-galactosidase during bread baking

NARCIS (Netherlands)

Zhang, L.; Chen, Xiao Dong; Boom, R.M.; Schutyser, M.A.I.

2017-01-01

In this study, β-galactosidase was utilized as a model enzyme to investigate the mechanism of enzyme inactivation during bread baking. Thermal inactivation of β-galactosidase was investigated in a wheat flour/water system at varying temperature-moisture content combinations, and in bread during

Ebola Virus Inactivation by Detergents Is Annulled in Serum

NARCIS (Netherlands)

van Kampen, Jeroen J. A.; Tintu, Andrei; Russcher, Henk; Fraaij, Pieter L. A.; Reusken, Chantal B. E. M.; Rijken, Mikel; van Hellemond, Jaap J.; van Genderen, Perry J. J.; Koelewijn, Rob; de Jong, Menno D.; Haddock, Elaine; Fischer, Robert J.; Munster, Vincent J.; Koopmans, Marion P. G.

2017-01-01

Treatment of blood samples from hemorrhagic fever virus (HFV)-infected patients with 0.1% detergents has been recommended for virus inactivation and subsequent safe laboratory testing. However, data on virus inactivation by this procedure are lacking. Here we show the effect of this procedure on

Rapid Bedside Inactivation of Ebola Virus for Safe Nucleic Acid Tests

DEFF Research Database (Denmark)

Rosenstierne, Maiken Worsøe; Karlberg, Helen; Bragstad, Karoline

2016-01-01

Rapid bedside inactivation of Ebola virus would be a solution for the safety of medical and technical staff, risk containment, sample transport, and high-throughput or rapid diagnostic testing during an outbreak. We show that the commercially available Magna Pure lysis/binding buffer used...... for nucleic acid extraction inactivates Ebola virus. A rapid bedside inactivation method for nucleic acid tests is obtained by simply adding Magna Pure lysis/binding buffer directly into vacuum blood collection EDTA tubes using a thin needle and syringe prior to sampling. The ready-to-use inactivation vacuum...... tubes are stable for more than 4 months, and Ebola virus RNA is preserved in the Magna Pure lysis/binding buffer for at least 5 weeks independent of the storage temperature. We also show that Ebola virus RNA can be manually extracted from Magna Pure lysis/binding buffer-inactivated samples using...

Direct generation of titanium dioxide nanoparticles dispersion under supercritical conditions for photocatalytic active thermoplastic surfaces for microbiological inactivation

Energy Technology Data Exchange (ETDEWEB)

Zydziak, Nicolas, E-mail: nicolas.zydziak@kit.edu [Polymer Engineering Department, Fraunhofer Institute of Chemical Technology, Joseph-von-Fraunhofer-Str. 7, 76327 Pfinztal (Germany); Zanin, Maria-Helena Ambrosio [Laboratory of Chemical Processes and Particle Technology Bionanomanufacturing, Institute for Technological Research of the State of São Paulo – IPT, Av. Prof. Almeida Prado 532, Cidade Universitária, CEP 05508-901 São Paulo, SP (Brazil); Trick, Iris [Environmental Biotechnology and Bioprocess Engineering Department, Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstrasse 12, 70569 Stuttgart (Germany); Hübner, Christof [Polymer Engineering Department, Fraunhofer Institute of Chemical Technology, Joseph-von-Fraunhofer-Str. 7, 76327 Pfinztal (Germany)

2015-03-01

Thermoplastic poly(propylene) (PP) and acrylonitrile-butadiene-styrene (ABS) surfaces were coated with silica based films via the sol–gel process, containing titanium dioxide (TiO{sub 2}) as photocatalyst. TiO{sub 2} was previously synthesized via sol–gel and treated under supercritical conditions in water dispersions. The characterization of the TiO{sub 2} dispersions was performed via disc centrifuge to determine the particle size and via Raman spectroscopy and X-Ray Diffraction (XRD) to characterize the crystallinity of TiO{sub 2}. The synthesized TiO{sub 2} dispersions and commercially available TiO{sub 2} particles were incorporated in silica based films which were synthesized under acidic or basic conditions, leading to dense or porous films respectively. The morphology of the films was characterized via Scanning Electron Microscopy (SEM). The incorporation of synthesized TiO{sub 2} in the coating led to photocatalytically more active thermoplastic surfaces than films formulated with commercially available TiO{sub 2} as determined via dye discoloration test. A microbiological test performed with Sarcina lutea confirmed this result and showed an inactivation factor of 6 (99.9999%) after 24 h UV irradiation, for synthesized TiO{sub 2} incorporated in acidic formulated silica layer on ABS surfaces. - Highlights: • We report about photocatalytic layers formulated on thermoplastic surfaces. • We synthesized silica layer and TiO{sub 2} via sol–gel and supercritical treatment. • Amorphous, crystalline and commercial dispersions were generated and characterized. • The morphology of dense and porous photocatalytic layers is observed via SEM. • Discoloration and microbiological tests correlate activity and surface morphology.

Dorsal hippocampus inactivation impairs spontaneous recovery of Pavlovian magazine approach responding in rats

Science.gov (United States)

Campese, Vincent D.; Delamater, Andrew R.

2014-01-01

Destruction or inactivation of the dorsal hippocampus (DH) has been shown to eliminate the renewal of extinguished fear [1–4]. However, it has recently been reported that the contextual control of responding to extinguished appetitive stimuli is not disrupted when the DH is destroyed or inactivated prior to tests for renewal of Pavlovian conditioned magazine approach [5]. In the present study we extend the analysis of DH control of appetitive extinction learning to the spontaneous recovery of Pavlovian conditioned magazine approach responding. Subjects were trained to associate two separate stimuli with the delivery of food and had muscimol or vehicle infused into the DH prior to a single test-session for spontaneous recovery occurring immediately following extinction of one of these stimuli, but one week following extinction of the other. While vehicle treated subjects showed more recovery to the distally extinguished stimulus than the proximal one, muscimol treated subjects failed to show spontaneous recovery to either stimulus. This result suggests that, while the DH is not involved in the control of extinction by physical contexts [5], it may be involved when time is the gating factor controlling recovery of extinguished responding. PMID:24742862

High pressure inactivation of HAV within oysters: comparison of shucked oysters with whole in shell meats

Science.gov (United States)

High pressure inactivation of hepatitis A virus (HAV) within oysters bioaccumulated under simulated natural conditions to levels >106 PFU/oyster has been evaluated. Five min treatments at 20C were administered at 350, 375, and 400 MegaPascals (MPa). Shucked and whole-in-shell oysters were directly...

Strategy to inactivate Clostridium perfringens spores in meat products.

Science.gov (United States)

Akhtar, Saeed; Paredes-Sabja, Daniel; Torres, J Antonio; Sarker, Mahfuzur R

2009-05-01

The current study aimed to develop an inactivation strategy for Clostridium perfringens spores in meat through a combination of spore activation at low pressure (100-200 MPa, 7 min) and elevated temperature (80 degrees C, 10 min); spore germination at high temperatures (55, 60 or 65 degrees C); and inactivation of germinated spores with elevated temperatures (80 and 90 degrees C, 10 and 20 min) and high pressure (586 MPa, at 23 and 73 degrees C, 10 min). Low pressures (100-200 MPa) were insufficient to efficiently activate C. perfringens spores for germination. However, C. perfringens spores were efficiently activated with elevated temperature (80 degrees C, 10 min), and germinated at temperatures lethal for vegetative cells (>or= 55 degrees C) when incubated for 60 min with a mixture of L-asparagine and KCl (AK) in phosphate buffer (pH 7) and in poultry meat. Inactivation of spores (approximately 4 decimal reduction) in meat by elevated temperatures (80-90 degrees C for 20 min) required a long germination period (55 degrees C for 60 min). However, similar inactivation level was reached with shorter germination period (55 degrees C for 15 min) when spore contaminated-meat was treated with pressure-assisted thermal processing (568 MPa, 73 degrees C, 10 min). Therefore, the most efficient strategy to inactivate C. perfringens spores in poultry meat containing 50 mM AK consisted: (i) a primary heat treatment (80 degrees C, 10 min) to pasteurize and denature the meat proteins and to activate C. perfringens spores for germination; (ii) cooling of the product to 55 degrees C in about 20 min and further incubation at 55 degrees C for about 15 min for spore germination; and (iii) inactivation of germinated spores by pressure-assisted thermal processing (586 MPa at 73 degrees C for 10 min). Collectively, this study demonstrates the feasibility of an alternative and novel strategy to inactivate C. perfringens spores in meat products formulated with germinants specific for C

The radiation inactivation of glutamate and isocitrate dehydrogenases

International Nuclear Information System (INIS)

El Failat, R.R.A.

1980-12-01

The reaction of free radicals produced by ionizing radiation with the enzymes glutamate dehydrogenase (GDH) and NADP + -specific isocitrate dehydrogenase (ICDH) have been studied by steady-state and pulse radiolysis techniques. In de-aerated GDH solutions, hydroxyl radicals have been found to be the most efficient of the primary radicals generated from water in causing inactivation. The effect of reaction with the enzyme of selective free radicals (SCN) 2 - , (Br) 2 - and (I) 2 - on its activity has also been studied. In neutral solutions, the order of inactivating effectiveness is (I) 2 - > (Br) 2 - > (SCN) 2 - . In the case of the thiocyanate radical anion (SCN) 2 - , the inactivation efficiency is found to depend on KSCN concentration. The radiation inactivation of GDH at both neutral and alkaline pH is accompanied by the loss of sulphydryl groups. Pulse radiolysis was also used to determine the rate constants and the transient absorption spectra following the reaction of the free radicals with GDH. 60 Co-γ-radiolysis and pulse radiolysis were also used to study the effect of ionizing radiation on the activity of ICDH. The results obtained were similar to those of GDH. (author)

The inactivation of papain by high LET radiations

International Nuclear Information System (INIS)

Bisby, R.H.; Cundall, R.B.; Sims, H.E.; Burns, W.G.

1984-01-01

The effect of varying LET over a wide range (0.2-1570 eV/nm) on the radiation-induced inactivation of the enzyme papain in dilute aqueous solution has been investigated. Measurements of total, reparable and non-reparable inactivation G values in oxygen, nitrous oxide and argon saturated solutions have allowed the contributions to inactivation from radicals and hydrogen peroxide to be evaluated. At high LET the results demonstrate an increasing component due to reaction of the superoxide radical, formed from oxygen produced in the track as a primary radiolysis product. This effect was not observed in our previous study with ribonuclease due to the insensitivity of ribonuclease to inactivation by superoxide and hydrogen peroxide. The results obtained with papain clearly demonstrate a maximum in G(H 2 O 2 ) at an LET of equivalent to 140 eV/nm. Generation of O 2 within the track as a primary radiolysis product at high LET now appears to be confirmed as an important mechanism leading to reduction in the oxygen enhancement ratio for cellular systems exposed to high LET radiations (Baverstock and Burns 1981). (author)

Photodynamic inactivation of Candida albicans sensitized by tri- and tetra-cationic porphyrin derivatives.

Science.gov (United States)

Cormick, M Paula; Alvarez, M Gabriela; Rovera, Marisa; Durantini, Edgardo N

2009-04-01

The photodynamic action of 5-(4-trifluorophenyl)-10,15,20-tris(4-trimethylammoniumphenyl)porphyrin iodide (TFAP(3+)) and 5,10,15,20-tetra(4-N,N,N-trimethylammonium phenyl)porphyrin p-tosylate (TMAP(4+)) has been studied in vitro on Candida albicans. The results of these cationic porphyrins were compared with those of 5,10,15,20-tetra(4-sulphonatophenyl)porphyrin (TPPS(4-)), which characterizes an anionic sensitizer. In vitro investigations show that these cationic porphyrins are rapidly bound to C. albicans cells, reaching a value of approximately 1.4 nmol/10(6) cells, when the cellular suspensions were incubated with 5 microM sensitizer for 30 min. In contrast, TPPS(4-) is poorly uptaken by yeast cells. The fluorescence spectra of these sensitizers into the cells confirm this behaviour. The amount of porphyrin binds to cells is dependent on both sensitizer concentrations (1-5 microM) and cells densities (10(6)-10(8) cells/mL). Photosensitized inactivation of C. albicans cellular suspensions increases with sensitizer concentration, causing a approximately 5 log decrease of cell survival, when the cultures are treated with 5 microM of cationic porphyrin and irradiated for 30 min. However, the photocytotoxicity decreases with an increase in the cell density, according to its low binding to cells. Under these conditions, the photodynamic activity of TFAP(3+) is quite similar to that produced by TMAP(4+), whereas no important inactivation effect was found for TPPS(4)(-). The high photodynamic activity of cationic porphyrins was confirmed by growth delay experiments. Thus, C. albicans cell growth was not detected in the presence of 5 microM TFAP(3+). Photodynamic inactivation capacities of these sensitizers were also evaluated on C. albicans cells growing in colonies on agar surfaces. Cationic porphyrins produce a growth delay of C. albicans colonies and viability of cells was not observed after 3 h irradiation, indicating a complete inactivation of yeast cells

Pulsed electric fields for pasteurization: defining processing conditions

Science.gov (United States)

Application of pulsed electric fields (PEF) technology in food pasteurization has been extensively studied. Optimal PEF treatment conditions for maximum microbial inactivation depend on multiple factors including PEF processing conditions, production parameters and product properties. In order for...

Design and mechanism of tetrahydrothiophene-based γ-aminobutyric acid aminotransferase inactivators.

Science.gov (United States)

Le, Hoang V; Hawker, Dustin D; Wu, Rui; Doud, Emma; Widom, Julia; Sanishvili, Ruslan; Liu, Dali; Kelleher, Neil L; Silverman, Richard B

2015-04-08

Low levels of γ-aminobutyric acid (GABA), one of two major neurotransmitters that regulate brain neuronal activity, are associated with many neurological disorders, such as epilepsy, Parkinson's disease, Alzheimer's disease, Huntington's disease, and cocaine addiction. One of the main methods to raise the GABA level in human brain is to use small molecules that cross the blood-brain barrier and inhibit the activity of γ-aminobutyric acid aminotransferase (GABA-AT), the enzyme that degrades GABA. We have designed a series of conformationally restricted tetrahydrothiophene-based GABA analogues with a properly positioned leaving group that could facilitate a ring-opening mechanism, leading to inactivation of GABA-AT. One compound in the series is 8 times more efficient an inactivator of GABA-AT than vigabatrin, the only FDA-approved inactivator of GABA-AT. Our mechanistic studies show that the compound inactivates GABA-AT by a new mechanism. The metabolite resulting from inactivation does not covalently bind to amino acid residues of GABA-AT but stays in the active site via H-bonding interactions with Arg-192, a π-π interaction with Phe-189, and a weak nonbonded S···O═C interaction with Glu-270, thereby inactivating the enzyme.

Design and Mechanism of Tetrahydrothiophene-Based γ-Aminobutyric Acid Aminotransferase Inactivators

Energy Technology Data Exchange (ETDEWEB)

Le, Hoang V. [Departments; Hawker, Dustin D. [Departments; Wu, Rui [Department; Doud, Emma [Departments; Widom, Julia [Departments; Sanishvili, Ruslan [X-ray; Liu, Dali [Department; Kelleher, Neil L. [Departments; Silverman, Richard B. [Departments

2015-03-25

Low levels of gamma-aminobutyric acid (GABA), one of two major neurotransmitters that regulate brain neuronal activity, are associated with many neurological disorders, such as epilepsy, Parkinsons disease, Alzheimers disease, Huntingtons disease, and cocaine addiction. One of the main methods to raise the GABA level in human brain is to use small molecules that cross the bloodbrain barrier and inhibit the activity of gamma-aminobutyric acid aminotransferase (GABA-AT), the enzyme that degrades GABA. We have designed a series of conformationally restricted tetrahydrothiophene-based GABA analogues with a properly positioned leaving group that could facilitate a ring-opening mechanism, leading to inactivation of GABA-AT. One compound in the series is 8 times more efficient an inactivator of GABA-AT than vigabatrin, the only FDA-approved inactivator of GABA-AT. Our mechanistic studies show that the compound inactivates GABA-AT by a new mechanism. The metabolite resulting from inactivation does not covalently bind to amino acid residues of GABA-AT but stays in the active site via H-bonding interactions with Arg-192, a pi-pi interaction with Phe-189, and a weak nonbonded (SO)-O-...=C interaction with Glu-270, thereby inactivating the enzyme.

Gamma-irradiation to inactivate thioglucosidase of crucifers

International Nuclear Information System (INIS)

Lessman, K.J.; McCaslin, B.D.

1987-01-01

The crucifers contain glucosinolates which through enzymatic hydrolysis give rise to toxicants that limit the use of oil-free meal obtainable from this plant family. Seeds from three crucifers were used to test gamma irradiation to inactivate enzyme systems as a step toward detoxification. Seeds of Crambe abyssinica Hochst (crambe), ground seeds of Sinapis alba L. (mustard), and seeds of Brassica napus L. (rape) were subjected to gamma-irradiation (6.25, 12.5, 25.0 and 50.4 Mrad) to inactivate thioglucosidase and/or destroy glucosinolates. Samples of ground seeds, their oil-free meals, previously irradiated ground seeds and their oil-free meals were assayed for glucose, a product of enzymatic hydrolysis of glucosinolates present in the crucifer seeds. The 50.4 Mrad exposure inactivated thioglucosidase but did not destroy glucosinolates. The fatty acid contents of extracted oils were affected. The amino acid profile of defatted crambe protein meal was affected, while that of white mustard was not

Dynamic changes in GABAA receptors on basal forebrain cholinergic neurons following sleep deprivation and recovery

Directory of Open Access Journals (Sweden)

Jones Barbara E

2007-02-01

Full Text Available Abstract Background The basal forebrain (BF cholinergic neurons play an important role in cortical activation and arousal and are active in association with cortical activation of waking and inactive in association with cortical slow wave activity of sleep. In view of findings that GABAA receptors (Rs and inhibitory transmission undergo dynamic changes as a function of prior activity, we investigated whether the GABAARs on cholinergic cells might undergo such changes as a function of their prior activity during waking vs. sleep. Results In the brains of rats under sleep control (SC, sleep deprivation (SD or sleep recovery (SR conditions in the 3 hours prior to sacrifice, we examined immunofluorescent staining for β2–3 subunit GABAARs on choline acetyltransferase (ChAT immunopositive (+ cells in the magnocellular BF. In sections also stained for c-Fos, β2–3 GABAARs were present on ChAT+ neurons which expressed c-Fos in the SD group alone and were variable or undetectable on other ChAT+ cells across groups. In dual-immunostained sections, the luminance of β2–3 GABAARs over the membrane of ChAT+ cells was found to vary significantly across conditions and to be significantly higher in SD than SC or SR groups. Conclusion We conclude that membrane GABAARs increase on cholinergic cells as a result of activity during sustained waking and reciprocally decrease as a result of inactivity during sleep. These changes in membrane GABAARs would be associated with increased GABA-mediated inhibition of cholinergic cells following prolonged waking and diminished inhibition following sleep and could thus reflect a homeostatic process regulating cholinergic cell activity and thereby indirectly cortical activity across the sleep-waking cycle.

The pulsed light inactivation of veterinary relevant microbial biofilms ...

African Journals Online (AJOL)

Results show that both Cryptosporidium and Giardia attach to biofilms in large numbers (100-1000 oo/cysts) in as little as 72 hours. Pulsed light successfully inactivated all test species (Listeria, Salmonella, Bacillus, Escherichia) in planktonic and biofilm form with an increase in inactivation for every increase in UV dose.

Algal bloom sedimentation induces variable control of lake eutrophication by phosphorus inactivating agents

Energy Technology Data Exchange (ETDEWEB)

Wang, Changhui [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Bai, Leilei [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate University of Chinese Academy of Sciences (China); Jiang, He-Long, E-mail: hljiang@niglas.ac.cn [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Xu, Huacheng [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China)

2016-07-01

Lake eutrophication typically occurs with a syndrome of algae breeding and biomass accumulation (e.g., algal blooms). Therefore, the effect of algal bloom sedimentation on eutrophication control by phosphorus (P) inactivating agents was assessed herein. Three commercial products, including aluminum (Al) sulfate, iron (Fe) sulfate, and a lanthanum-modified clay (Phoslock®), as well as one easily available by-product, drinking water treatment residue (DWTR), were selected. The most important finding was that during algae sedimentation, P immobilization from the overlying water by Al, Phoslock®, and DWTR was dominated by a long-term slow phase (> 150 d), while Fe has limited effectiveness on the immobilization. Further analysis indicated that the algae sedimentation effect was mainly due to the slow release of P from algae, leading to relatively limited P available for the inactivating agents. Then, a more unfavorable effect on the P immobilization capability of inactivating agents was caused by the induced anaerobic conditions, the released organic matter from algae, and the increased sulfide in the overlying water and sediments during sedimentation. Overall, algae sedimentation induced variable control of eutrophication by P inactivating agents. Accordingly, recommendations for future works about algal lake restoration were also proposed. - Highlights: • A long-term P immobilization by Phoslock®, DWTR, and Al was observed. • Fe had limited effectiveness on P pollution control for overlying water. • Al and Fe enhanced sulfur reduction, while DWTR and Phoslock® had minor effect. • The sedimentation reduced Al and La release from agents, but enhanced Fe release. • The agents changed organic matter compositions and structures in water columns.

Experiments with a homologous, inactivated canine parvovirus vaccine in vaccination programmers for dogs.

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Wilson, J H; Hermann-Dekkers, W M

1982-01-01

The significance of canine parvovirus (CPV) infections as a permanent threat susceptible dogs, in particular pups, made the authors develop three liquid homologous inactivated adjuvant CPV vaccines that were compatible with existing canine vaccines and could be incorporated in current vaccination programmes. On vaccine (Kavak Parvo) contained only the CPV component, the second product (Kavak i-LP) also contained two inactivated leptospiral antigens, and the third vaccine (Kavak i-HLP) contained in addition an inactivated canine hepatitis virus. This paper reports on the studies conducted to test the safety and efficacy of the three products. They were used as such and as diluents for freeze dried vaccines containing live attenuated measles, distemper, and hepatitis viruses. The study was performed in a breeding kennel where all dogs were free from CPV antibodies and the nonvaccinated sentinels remained so for the course of the study. All vaccines proved to be safe in dogs of all ages, including pregnant bitches. The efficacy of the CPV component was studied both by monitoring antibody titres for more than a year and by challenge exposure of some dogs to virulent CPV. The results obtained from these studies prove that the CPV component used in the three vaccines can be incorporated as indicated in the recommended canine vaccination programmes. The observations that the inactivated CPV and hepatitis components do induce an active immunity in pups that are still protected by low levels of maternally derived antibodies against these viruses, make those vaccines very suitable in breeding kennels. Additional studies on a comparative basis are being continued in edemically CPV infected breeding kennels to quantify the significance of these observations in these special conditions.

Algal bloom sedimentation induces variable control of lake eutrophication by phosphorus inactivating agents

International Nuclear Information System (INIS)

Wang, Changhui; Bai, Leilei; Jiang, He-Long; Xu, Huacheng

2016-01-01

Lake eutrophication typically occurs with a syndrome of algae breeding and biomass accumulation (e.g., algal blooms). Therefore, the effect of algal bloom sedimentation on eutrophication control by phosphorus (P) inactivating agents was assessed herein. Three commercial products, including aluminum (Al) sulfate, iron (Fe) sulfate, and a lanthanum-modified clay (Phoslock®), as well as one easily available by-product, drinking water treatment residue (DWTR), were selected. The most important finding was that during algae sedimentation, P immobilization from the overlying water by Al, Phoslock®, and DWTR was dominated by a long-term slow phase (> 150 d), while Fe has limited effectiveness on the immobilization. Further analysis indicated that the algae sedimentation effect was mainly due to the slow release of P from algae, leading to relatively limited P available for the inactivating agents. Then, a more unfavorable effect on the P immobilization capability of inactivating agents was caused by the induced anaerobic conditions, the released organic matter from algae, and the increased sulfide in the overlying water and sediments during sedimentation. Overall, algae sedimentation induced variable control of eutrophication by P inactivating agents. Accordingly, recommendations for future works about algal lake restoration were also proposed. - Highlights: • A long-term P immobilization by Phoslock®, DWTR, and Al was observed. • Fe had limited effectiveness on P pollution control for overlying water. • Al and Fe enhanced sulfur reduction, while DWTR and Phoslock® had minor effect. • The sedimentation reduced Al and La release from agents, but enhanced Fe release. • The agents changed organic matter compositions and structures in water columns.

Capsid protein oxidation in feline calicivirus using an electrochemical inactivation treatment

Energy Technology Data Exchange (ETDEWEB)

Shionoiri, Nozomi; Nogariya, Osamu; Tanaka, Masayoshi; Matsunaga, Tadashi; Tanaka, Tsuyoshi, E-mail: tsuyo@cc.tuat.ac.jp

2015-02-11

Highlights: • Feline calicivirus was inactivated electrochemically by a factor of >5 log. • The electrochemical treatment was performed at 0.9 V (vs. Ag/AgCl) for 15 min. • Electrochemical treatment caused oxidation of viral proteins. • Oxidation of viral proteins can lead to loss of viral structural integrity. - Abstract: Pathogenic viral infections are an international public health concern, and viral disinfection has received increasing attention. Electrochemical treatment has been used for treatment of water contaminated by bacteria for several decades, and although in recent years several reports have investigated viral inactivation kinetics, the mode of action of viral inactivation by electrochemical treatment remains unclear. Here, we demonstrated the inactivation of feline calicivirus (FCV), a surrogate for human noroviruses, by electrochemical treatment in a developed flow-cell equipped with a screen-printed electrode. The viral infectivity titer was reduced by over 5 orders of magnitude after 15 min of treatment at 0.9 V vs. Ag/AgCl. Proteomic study of electrochemically inactivated virus revealed oxidation of peptides located in the viral particles; oxidation was not observed in the non-treated sample. Furthermore, transmission electron microscopy revealed that viral particles in the treated sample had irregular structures. These results suggest that electrochemical treatment inactivates FCV via oxidation of peptides in the structural region, causing structural deformation of virus particles. This first report of viral protein damage through electrochemical treatment will contribute to broadening the understanding of viral inactivation mechanisms.

Cytoskeletal Regulation Dominates Temperature-Sensitive Proteomic Changes of Hibernation in Forebrain of 13-Lined Ground Squirrels

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Hindle, Allyson G.; Martin, Sandra L.

2013-01-01

13-lined ground squirrels, Ictidomys tridecemlineatus, are obligate hibernators that transition annually between summer homeothermy and winter heterothermy – wherein they exploit episodic torpor bouts. Despite cerebral ischemia during torpor and rapid reperfusion during arousal, hibernator brains resist damage and the animals emerge neurologically intact each spring. We hypothesized that protein changes in the brain underlie winter neuroprotection. To identify candidate proteins, we applied a sensitive 2D gel electrophoresis method to quantify protein differences among forebrain extracts prepared from ground squirrels in two summer, four winter and fall transition states. Proteins that differed among groups were identified using LC-MS/MS. Only 84 protein spots varied significantly among the defined states of hibernation. Protein changes in the forebrain proteome fell largely into two reciprocal patterns with a strong body temperature dependence. The importance of body temperature was tested in animals from the fall; these fall animals use torpor sporadically with body temperatures mirroring ambient temperatures between 4 and 21°C as they navigate the transition between summer homeothermy and winter heterothermy. Unlike cold-torpid fall ground squirrels, warm-torpid individuals strongly resembled the homeotherms, indicating that the changes observed in torpid hibernators are defined by body temperature, not torpor per se. Metabolic enzymes were largely unchanged despite varied metabolic activity across annual and torpor-arousal cycles. Instead, the majority of the observed changes were cytoskeletal proteins and their regulators. While cytoskeletal structural proteins tended to differ seasonally, i.e., between summer homeothermy and winter heterothermy, their regulatory proteins were more strongly affected by body temperature. Changes in the abundance of various isoforms of the microtubule assembly and disassembly regulatory proteins dihydropyrimidinase

Cytoskeletal regulation dominates temperature-sensitive proteomic changes of hibernation in forebrain of 13-lined ground squirrels.

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Allyson G Hindle

Full Text Available 13-lined ground squirrels, Ictidomys tridecemlineatus, are obligate hibernators that transition annually between summer homeothermy and winter heterothermy - wherein they exploit episodic torpor bouts. Despite cerebral ischemia during torpor and rapid reperfusion during arousal, hibernator brains resist damage and the animals emerge neurologically intact each spring. We hypothesized that protein changes in the brain underlie winter neuroprotection. To identify candidate proteins, we applied a sensitive 2D gel electrophoresis method to quantify protein differences among forebrain extracts prepared from ground squirrels in two summer, four winter and fall transition states. Proteins that differed among groups were identified using LC-MS/MS. Only 84 protein spots varied significantly among the defined states of hibernation. Protein changes in the forebrain proteome fell largely into two reciprocal patterns with a strong body temperature dependence. The importance of body temperature was tested in animals from the fall; these fall animals use torpor sporadically with body temperatures mirroring ambient temperatures between 4 and 21°C as they navigate the transition between summer homeothermy and winter heterothermy. Unlike cold-torpid fall ground squirrels, warm-torpid individuals strongly resembled the homeotherms, indicating that the changes observed in torpid hibernators are defined by body temperature, not torpor per se. Metabolic enzymes were largely unchanged despite varied metabolic activity across annual and torpor-arousal cycles. Instead, the majority of the observed changes were cytoskeletal proteins and their regulators. While cytoskeletal structural proteins tended to differ seasonally, i.e., between summer homeothermy and winter heterothermy, their regulatory proteins were more strongly affected by body temperature. Changes in the abundance of various isoforms of the microtubule assembly and disassembly regulatory proteins

Inactivation of Heterosigma akashiwo in ballast water by circular orifice plate-generated hydrodynamic cavitation.

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Feng, Daolun; Zhao, Jie; Liu, Tian

2016-01-01

The discharge of alien ballast water is a well-known, major reason for marine species invasion. Here, circular orifice plate-generated hydrodynamic cavitation was used to inactivate Heterosigma akashiwo in ballast water. In comparison with single- and multihole orifice plates, the conical-hole orifice plate yielded the highest inactivation percentage, 51.12%, and consumed only 6.84% energy (based on a 50% inactivation percentage). Repeating treatment, either using double series-connection or circling inactivation, elevated the inactivation percentage, yet consumed much more energy. The results indicate that conical-hole-generated hydrodynamic cavitation shows great potential as a pre-inactivation method for ballast water treatment.

Effect of electron-beams irradiation for inactivation of microorganisms on spices

International Nuclear Information System (INIS)

Ito, Hitoshi; Islam, Md.S.

1993-01-01

Total aerobic bacteria in spices used in this study were determined to be 1x10 6 to 6x10 7 per gram. A study on the inactivation of microorganisms in spices showed that doses of 6 to 9 kGy of EB (electron-beams) or gamma irradiation were required to reduce the total aerobic bacteria tobelow 10 3 per gram. However, a little increase of resistance was observed on the inactivation of total aerobic bacteria in many spices in case of EB irradiation. These difference of radiation sensitivities between EB and gamma-rays was explained by dose rate effect on oxidation damage to microorganisms from the results of radiation sensitivities of Bacillus pumilus and B. megaterium spores at dry conditions. On the other hand, these high dose rate of EB irradiation suppressed the increase of peroxide values in spices at high dose irradiation up to 80 kGy. Components of essential oils in spices were not changed even irradiated up to 50 kGy with EB and gamma-rays. (author)

Factors affecting the In Vitro inactivation of adolase by x-rays

Energy Technology Data Exchange (ETDEWEB)

Quintiliani, M.; Boccacci, M.

1962-08-15

The influence of urea and of various protective compounds on the in vitro inactivation of aldolase by x rays was studied. Low concentrations of urea protect the enzyme from the inactivation, whereas high concentrations, able to induce an unfolding of the protein molecule, increase the degree inactivation by a given dose of radiation. Cysteamine, cystamine, aminoethyl-isothio-uronium, and glutathione, all protect the aldolase in solution from the inactivation by x rays. Cystamine is as protective as cysteamine, in equimolecular concentrations, when high inactivation levels are reached. No protection can be demonstrated when the aldolase, after incubation with the tested compounds, is precipitated and redissolved in a new medium before irradiation. Nevertheless, with S/sup 35/ labeled cystamine, it can be demonstrated that at least seven residues of cysteamine are bound to each aldolase molecule. The protective power of glutathione is reduced by a factor of about 0.2 in the presence of 4 M urea. The possible implications of these findings are discussed. (auth)

Mechanistic and kinetic aspects of microbial inactivation in food irradiation processes

International Nuclear Information System (INIS)

Tukenmez, I.

2004-01-01

Full text: A proper reaction mechanism was searched by analyzing the inactivation processes of microorganisms during food irradiation by ionizing radiation. By employing transition-state theory, it was assumed that the overall inactivation process involves a reversible sub-lethal stress and repair reactions to form reversibly injured cell or sensitized cell, which then undergoes irreversible injury leading to dead cell. A shoulder in low dose range in survival kinetics was associated with the repair process. Depending on the postulated mechanism, kinetic model equations were derived. The kinetics of cell inactivation by irradiation was expressed as depending on irradiation dose. By using experimental data in the developed model the inactivation parameters including threshold dose, radiation yield, decimal reduction dose and minimum sterilization dose were evaluated and microbial inactivation by irradiation was simulated by using the numerical values of the parameters. Developed model and model parameters may be used for the process control and the assessment of product quality in radiation preservation of food

A molecular switch driving inactivation in the cardiac K+ channel HERG.

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David A Köpfer

Full Text Available K(+ channels control transmembrane action potentials by gating open or closed in response to external stimuli. Inactivation gating, involving a conformational change at the K(+ selectivity filter, has recently been recognized as a major K(+ channel regulatory mechanism. In the K(+ channel hERG, inactivation controls the length of the human cardiac action potential. Mutations impairing hERG inactivation cause life-threatening cardiac arrhythmia, which also occur as undesired side effects of drugs. In this paper, we report atomistic molecular dynamics simulations, complemented by mutational and electrophysiological studies, which suggest that the selectivity filter adopts a collapsed conformation in the inactivated state of hERG. The selectivity filter is gated by an intricate hydrogen bond network around residues S620 and N629. Mutations of this hydrogen bond network are shown to cause inactivation deficiency in electrophysiological measurements. In addition, drug-related conformational changes around the central cavity and pore helix provide a functional mechanism for newly discovered hERG activators.

Cholinergic Neurons in the Basal Forebrain Promote Wakefulness by Actions on Neighboring Non-Cholinergic Neurons: An Opto-Dialysis Study.

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Zant, Janneke C; Kim, Tae; Prokai, Laszlo; Szarka, Szabolcs; McNally, James; McKenna, James T; Shukla, Charu; Yang, Chun; Kalinchuk, Anna V; McCarley, Robert W; Brown, Ritchie E; Basheer, Radhika

2016-02-10

Understanding the control of sleep-wake states by the basal forebrain (BF) poses a challenge due to the intermingled presence of cholinergic, GABAergic, and glutamatergic neurons. All three BF neuronal subtypes project to the cortex and are implicated in cortical arousal and sleep-wake control. Thus, nonspecific stimulation or inhibition studies do not reveal the roles of these different neuronal types. Recent studies using optogenetics have shown that "selective" stimulation of BF cholinergic neurons increases transitions between NREM sleep and wakefulness, implicating cholinergic projections to cortex in wake promotion. However, the interpretation of these optogenetic experiments is complicated by interactions that may occur within the BF. For instance, a recent in vitro study from our group found that cholinergic neurons strongly excite neighboring GABAergic neurons, including the subset of cortically projecting neurons, which contain the calcium-binding protein, parvalbumin (PV) (Yang et al., 2014). Thus, the wake-promoting effect of "selective" optogenetic stimulation of BF cholinergic neurons could be mediated by local excitation of GABA/PV or other non-cholinergic BF neurons. In this study, using a newly designed opto-dialysis probe to couple selective optical stimulation with simultaneous in vivo microdialysis, we demonstrated that optical stimulation of cholinergic neurons locally increased acetylcholine levels and increased wakefulness in mice. Surprisingly, the enhanced wakefulness caused by cholinergic stimulation was abolished by simultaneous reverse microdialysis of cholinergic receptor antagonists into BF. Thus, our data suggest that the wake-promoting effect of cholinergic stimulation requires local release of acetylcholine in the basal forebrain and activation of cortically projecting, non-cholinergic neurons, including the GABAergic/PV neurons. Optogenetics is a revolutionary tool to assess the roles of particular groups of neurons in behavioral

Comparison of glycerolisation with cryopreservation methods on HIV-1 inactivation

International Nuclear Information System (INIS)

Van Baare, J.; Pagnon, J.; Cameron, P.; Vardaxis, N.; Middlekoop, E.; Crowe, S.

1999-01-01

Cryopreservation and glycerolisation are two successful long-term preservation methods for human cadaveric donor skin, which is used in the treatment of bum patients. High concentrations of glycerol has been shown to be antibacterial and virucidal. Because fear of possible transmission of HIV-1 following allograft transplantation, this study was undertaken to investigate whether HIV can be effectively eliminated from skin explants. HIV-1 Ba-L, which has been shown to infect monocytes in skin explants and also dendritic cells, was. For the experiments we used cell-free virus, exogenously HIV infected peripheral blood mononuclear cells (PBMCs) and exogenously HIV infected cadaver split skin. Different concentrations of glycerol at various temperatures and the glycerolisation procedure as used by the Euro Skin Bank were used to determine the effects on HIV-1 Ba-L infectivity. For the cryopreservation technique we used 10% DMSO and a controlled rate freezer. HIV-1 Ba-L transfer was determined by adding uninfected PBMCs to the infected material and reverse transcriptase was measured. Cell-free HIV-1 Ba-L was not inactivated by 50% glycerol but was effectively inactivated within 30 minutes by 70% and 85% glycerol at 4 degree C, room temperature and 37 degree C. In contrast, cell-free HIV-1 Ba-L was not inactivated by cryopreservation. Most importantly, we have shown that HIV-1 Ba-L present in split skin is inactivated by incubating skin in 70% glycerol for three hours at 37-C. HIV in exogenously infected skin was not inactivated by cryopreservation. High concentrations of glycerol effectively inactivates free HIV-1 Ba-L and intracellular HIV-1 Ba-L. Also the current glycerolisation procedure carried out by the Euro Skin Bank effectively inactivates infectious virus. However, the cryopreservation technique did not show any reduction in HIV-1 Ba-L infectivity

Optimising the inactivation of grape juice spoilage organisms by pulse electric fields.

Science.gov (United States)

Marsellés-Fontanet, A Robert; Puig, Anna; Olmos, Paola; Mínguez-Sanz, Santiago; Martín-Belloso, Olga

2009-04-15

The effect of some pulsed electric field (PEF) processing parameters (electric field strength, pulse frequency and treatment time), on a mixture of microorganisms (Kloeckera apiculata, Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus hilgardii and Gluconobacter oxydans) typically present in grape juice and wine were evaluated. An experimental design based on response surface methodology (RSM) was used and results were also compared with those of a factorially designed experiment. The relationship between the levels of inactivation of microorganisms and the energy applied to the grape juice was analysed. Yeast and bacteria were inactivated by the PEF treatments, with reductions that ranged from 2.24 to 3.94 log units. All PEF parameters affected microbial inactivation. Optimal inactivation of the mixture of spoilage microorganisms was predicted by the RSM models at 35.0 kV cm(-1) with 303 Hz pulse width for 1 ms. Inactivation was greater for yeasts than for bacteria, as was predicted by the RSM. The maximum efficacy of the PEF treatment for inactivation of microorganisms in grape juice was observed around 1500 MJ L(-1) for all the microorganisms investigated. The RSM could be used in the fruit juice industry to optimise the inactivation of spoilage microorganisms by PEF.

Hypocretin/orexin antagonism enhances sleep-related adenosine and GABA neurotransmission in rat basal forebrain.

Science.gov (United States)

Vazquez-DeRose, Jacqueline; Schwartz, Michael D; Nguyen, Alexander T; Warrier, Deepti R; Gulati, Srishti; Mathew, Thomas K; Neylan, Thomas C; Kilduff, Thomas S

2016-03-01

Hypocretin/orexin (HCRT) neurons provide excitatory input to wake-promoting brain regions including the basal forebrain (BF). The dual HCRT receptor antagonist almorexant (ALM) decreases waking and increases sleep. We hypothesized that HCRT antagonists induce sleep, in part, through disfacilitation of BF neurons; consequently, ALM should have reduced efficacy in BF-lesioned (BFx) animals. To test this hypothesis, rats were given bilateral IgG-192-saporin injections, which predominantly targets cholinergic BF neurons. BFx and intact rats were then given oral ALM, the benzodiazepine agonist zolpidem (ZOL) or vehicle (VEH) at lights-out. ALM was less effective than ZOL at inducing sleep in BFx rats compared to controls. BF adenosine (ADO), γ-amino-butyric acid (GABA), and glutamate levels were then determined via microdialysis from intact, freely behaving rats following oral ALM, ZOL or VEH. ALM increased BF ADO and GABA levels during waking and mixed vigilance states, and preserved sleep-associated increases in GABA under low and high sleep pressure conditions. ALM infusion into the BF also enhanced cortical ADO release, demonstrating that HCRT input is critical for ADO signaling in the BF. In contrast, oral ZOL and BF-infused ZOL had no effect on ADO levels in either BF or cortex. ALM increased BF ADO (an endogenous sleep-promoting substance) and GABA (which is increased during normal sleep), and required an intact BF for maximal efficacy, whereas ZOL blocked sleep-associated BF GABA release, and required no functional contribution from the BF to induce sleep. ALM thus induces sleep by facilitating the neural mechanisms underlying the normal transition to sleep.

Epigenetic inactivation of CHFR in human tumors.

Science.gov (United States)

Toyota, Minoru; Sasaki, Yasushi; Satoh, Ayumi; Ogi, Kazuhiro; Kikuchi, Takefumi; Suzuki, Hiromu; Mita, Hiroaki; Tanaka, Nobuyuki; Itoh, Fumio; Issa, Jean-Pierre J; Jair, Kam-Wing; Schuebel, Kornel E; Imai, Kohzoh; Tokino, Takashi

2003-06-24

Cell-cycle checkpoints controlling the orderly progression through mitosis are frequently disrupted in human cancers. One such checkpoint, entry into metaphase, is regulated by the CHFR gene encoding a protein possessing forkhead-associated and RING finger domains as well as ubiquitin-ligase activity. Although defects in this checkpoint have been described, the molecular basis and prevalence of CHFR inactivation in human tumors are still not fully understood. To address this question, we analyzed the pattern of CHFR expression in a number of human cancer cell lines and primary tumors. We found CpG methylation-dependent silencing of CHFR expression in 45% of cancer cell lines, 40% of primary colorectal cancers, 53% of colorectal adenomas, and 30% of primary head and neck cancers. Expression of CHFR was precisely correlated with both CpG methylation and deacetylation of histones H3 and H4 in the CpG-rich regulatory region. Moreover, CpG methylation and thus silencing of CHFR depended on the activities of two DNA methyltransferases, DNMT1 and DNMT3b, as their genetic inactivation restored CHFR expression. Finally, cells with CHFR methylation had an intrinsically high mitotic index when treated with microtubule inhibitor. This means that cells in which CHFR was epigenetically inactivated constitute loss-of-function alleles for mitotic checkpoint control. Taken together, these findings shed light on a pathway by which mitotic checkpoint is bypassed in cancer cells and suggest that inactivation of checkpoint genes is much more widespread than previously suspected.

Sleep-wake sensitive mechanisms of adenosine release in the basal forebrain of rodents: an in vitro study.

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Robert Edward Sims

Full Text Available Adenosine acting in the basal forebrain is a key mediator of sleep homeostasis. Extracellular adenosine concentrations increase during wakefulness, especially during prolonged wakefulness and lead to increased sleep pressure and subsequent rebound sleep. The release of endogenous adenosine during the sleep-wake cycle has mainly been studied in vivo with microdialysis techniques. The biochemical changes that accompany sleep-wake status may be preserved in vitro. We have therefore used adenosine-sensitive biosensors in slices of the basal forebrain (BFB to study both depolarization-evoked adenosine release and the steady state adenosine tone in rats, mice and hamsters. Adenosine release was evoked by high K(+, AMPA, NMDA and mGlu receptor agonists, but not by other transmitters associated with wakefulness such as orexin, histamine or neurotensin. Evoked and basal adenosine release in the BFB in vitro exhibited three key features: the magnitude of each varied systematically with the diurnal time at which the animal was sacrificed; sleep deprivation prior to sacrifice greatly increased both evoked adenosine release and the basal tone; and the enhancement of evoked adenosine release and basal tone resulting from sleep deprivation was reversed by the inducible nitric oxide synthase (iNOS inhibitor, 1400 W. These data indicate that characteristics of adenosine release recorded in the BFB in vitro reflect those that have been linked in vivo to the homeostatic control of sleep. Our results provide methodologically independent support for a key role for induction of iNOS as a trigger for enhanced adenosine release following sleep deprivation and suggest that this induction may constitute a biochemical memory of this state.

Ionic mechanisms of action of prion protein fragment PrP(106-126) in rat basal forebrain neurons.

Science.gov (United States)

Alier, Kwai; Li, Zongming; Mactavish, David; Westaway, David; Jhamandas, Jack H

2010-08-01

Prion diseases are neurodegenerative disorders that are characterized by the presence of the misfolded prion protein (PrP). Neurotoxicity in these diseases may result from prion-induced modulation of ion channel function, changes in neuronal excitability, and consequent disruption of cellular homeostasis. We therefore examined PrP effects on a suite of potassium (K(+)) conductances that govern excitability of basal forebrain neurons. Our study examined the effects of a PrP fragment [PrP(106-126), 50 nM] on rat neurons using the patch clamp technique. In this paradigm, PrP(106-126) peptide, but not the "scrambled" sequence of PrP(106-126), evoked a reduction of whole-cell outward currents in a voltage range between -30 and +30 mV. Reduction of whole-cell outward currents was significantly attenuated in Ca(2+)-free external media and also in the presence of iberiotoxin, a blocker of calcium-activated potassium conductance. PrP(106-126) application also evoked a depression of the delayed rectifier (I(K)) and transient outward (I(A)) potassium currents. By using single cell RT-PCR, we identified the presence of two neuronal chemical phenotypes, GABAergic and cholinergic, in cells from which we recorded. Furthermore, cholinergic and GABAergic neurons were shown to express K(v)4.2 channels. Our data establish that the central region of PrP, defined by the PrP(106-126) peptide used at nanomolar concentrations, induces a reduction of specific K(+) channel conductances in basal forebrain neurons. These findings suggest novel links between PrP signalling partners inferred from genetic experiments, K(+) channels, and PrP-mediated neurotoxicity.

UK-18,892: resistance to modification by aminoglycoside-inactivating enzymes.

Science.gov (United States)

Andrews, R J; Brammer, K W; Cheeseman, H E; Jevons, S

1978-12-01

UK-18,892, a new semisynthetic aminoglycoside, was active against bacteria possessing aminoglycoside-inactivating enzymes, with the exception of some known to possess AAC(6') or AAD(4') enzymes. This activity has been rationalized by using cell-free extracts of bacteria containing known inactivating enzymes, where it was shown that UK-18,892 was not a substrate for the APH(3'), AAD(2''), AAC(3), and AAC(2') enzymes. It was also demonstrated that UK-18,892 protected mice against lethal infections caused by organisms possessing aminoglycoside-inactivating enzymes.

Nonthermal inactivation of norovirus surrogates on blueberries using atmospheric cold plasma.

Science.gov (United States)

Lacombe, Alison; Niemira, Brendan A; Gurtler, Joshua B; Sites, Joseph; Boyd, Glenn; Kingsley, David H; Li, Xinhui; Chen, Haiqiang

2017-05-01

Viruses are currently the leading cause of foodborne outbreaks, most of which are associated with foods consumed raw. Cold plasma (CP) is an emerging novel nonthermal technology that can be used to surface decontaminate foods. This study investigated CP technology for the nonthermal inactivation of human norovirus surrogates, Tulane virus (TV) and murine norovirus (MNV), on the surface of blueberries. Blueberries (5 g) were weighed into sterile 4 oz. glass jars and inoculated with TV, 5 log PFU/g. Samples were treated with atmospheric CP for 0, 15, 30, 45, and 60 s at a working distance of 7.5 cm with 4 cubic feet/minute (cfm) of CP jet. Temperature readings were taken with an infrared camera prior to, and immediately following, CP treatments. In order to establish the impact of air flow during CP treatment (4 cfm), an additional 7 cfm jet of room temperature air was introduced from a separate nozzle. The experiment was repeated with 90 and 120 s as additional treatment time points. Viral titers were measured immediately after each treatment with a plaque assay using LLC-MK2 cells (TV) or RAW 264.7 cells (MNV). TV was significantly reduced 1.5 PFU/g compared to the control after treatment time of 45s, which was achieved regardless of temperature conditions. With the addition of 7 cfm of ambient air, the maximum log reduction for TV was 3.5 log PFU/g after 120s of treatment. MNV was significantly reduced by 0.5 log PFU/g compare to the control at 15s, and further treatment of MNV with ambient air brought the log reduction to greater than 5 log PFU/g at 90 s of treatment (Fig. 3). These results demonstrate that CP viral inactivation does not rely on thermal inactivation, and is therefore nonthermal in nature. With further optimization, CP may be used by food processors as a means of nonthermal inactivation of foodborne viruses. Published by Elsevier Ltd.

Inactivation and stability of viral diagnostic reagents treated by gamma radiation

International Nuclear Information System (INIS)

White, L.A.; Freeman, C.Y.; Hall, H.E.; Forrester, B.D.

1990-01-01

The objective of this study was to apply the pertinent findings from gamma inactivation of virus infectivity to the production of high quality diagnostic reagents. A Gammacell 220 was used to subject 38 viruses grown in either susceptible tissue cultures or embryonated chicken eggs to various doses of gamma radiation from a cobalt-60 source. The radiation required to reduce viral infectivity was 0.42 to 3.7 megarads (Mrad). The effect of gamma treatment on the antigenic reactivity of reagents for the complement fixation (CF), hemagglutination (HA) and neuraminadase assays was determined. Influenza antigens inactivated with 1.7 Mrad displayed comparable potency, sensitivity, specificity and stability to those inactivated by standard procedures with beta-propiolactone (BPL). Significant inactivation of influenza N1 and B neuraminidase occurred with >2.4 Mrad radiation at temperatures above 4 0 C. All 38 viruses were inactivated, and CF or HA antigens were prepared successfully. Antigenic potency remained stable with all antigens for 3 years and with 83% after 5 years storage. Influenza HA antigens evaluated after 9 years of storage demonstrated 86% stability. Gamma radiation is safer than chemical inactivation procedures and is a reliable and effective replacement for BPL in preparing diagnostic reagents. (author)

Inactivation and stability of viral diagnostic reagents treated by gamma radiation

Energy Technology Data Exchange (ETDEWEB)

White, L A; Freeman, C Y; Hall, H E; Forrester, B D [Department of Health and Human Services, Atlanta, GA (USA)

1990-10-01

The objective of this study was to apply the pertinent findings from gamma inactivation of virus infectivity to the production of high quality diagnostic reagents. A Gammacell 220 was used to subject 38 viruses grown in either susceptible tissue cultures or embryonated chicken eggs to various doses of gamma radiation from a cobalt-60 source. The radiation required to reduce viral infectivity was 0.42 to 3.7 megarads (Mrad). The effect of gamma treatment on the antigenic reactivity of reagents for the complement fixation (CF), hemagglutination (HA) and neuraminadase assays was determined. Influenza antigens inactivated with 1.7 Mrad displayed comparable potency, sensitivity, specificity and stability to those inactivated by standard procedures with beta-propiolactone (BPL). Significant inactivation of influenza N1 and B neuraminidase occurred with >2.4 Mrad radiation at temperatures above 4{sup 0}C. All 38 viruses were inactivated, and CF or HA antigens were prepared successfully. Antigenic potency remained stable with all antigens for 3 years and with 83% after 5 years storage. Influenza HA antigens evaluated after 9 years of storage demonstrated 86% stability. Gamma radiation is safer than chemical inactivation procedures and is a reliable and effective replacement for BPL in preparing diagnostic reagents. (author).

Development of inactivated-local isolate vaccine for infectious bronchitis

Directory of Open Access Journals (Sweden)

Darminto

1999-06-01

Full Text Available Infectious bronchitis (IB is an acute highly contagious viral respiratory disease of poultry caused by coronavirus. The disease causes high mortality in young chicks, reduce body weight gain in broilers and remarkable drop in egg production. IB can only be controlled by vaccination, but due to the antigenic variation among serotypes of IB viruses, the effective IB vaccine should be prepared from local isolates. The aim of this research is to develop inactivated IB vaccine derived from local IB isolates. Local isolates of IB viruses designated as I-37, I-269 and PTS-III were propagated respectively in specific pathogen free (SPF chicken eggs, the viruses then were inactivated by formaline at final concentration of 1:1,000. Subsequently, the inactivated viruses were mixed and emulsified in oil emulsion adjuvant with sorbitant mono-oleic as an emulsifier. The vaccine then was tested for its safety, potency and efficacy in broiler chickens. Birds inoculated twice with a two-week interval by inactivated vaccine did not show any adverse reaction, either systemic or local reaction. The inoculated birds developed antibody responses with high titre, while antibody of the control birds remain negative. In addition, efficacy test which was conducted in broilers demonstrated that birds vaccinated by live-commercial vaccine and boosted three weeks later by Balitvet inactivated vaccine showed high level of antibody production which provided high level of protection against challenged virus (76% against I-37, 92% against I-269 and 68% against PTS-III challenge viruses. From this study, it can be concluded that inactivated local IB vaccine is considered to be safe, potent and efficacious. The vaccine stimulates high titre of antibody responses, which provide high level of protection against challenged viruses.

Two-Dimensional Microdischarge Jet Array in Air: Characterization and Inactivation of Virus

Science.gov (United States)

Nayak, Gaurav

OES to measure the O2(a 1Deltag) density and spectrophotometry to estimate the NOx species density in aqueous medium. The results show that the discharge activity is strongly dependent on the gas flow rate particularly for gas residence times comparable to the applied high voltage cycle. The maximum difference in gas temperature at extreme plasma conditions do not exceed 50 K. The NO density is found to be reducing with smaller gas residence time. It is found that the reduced field E/N is dependent on the flow rate. The observed variation in the electric field is attributed to the change in the neutral gas densities. Both gas residence time and humidity have an impact on the space-charge distribution. The O 3 density is found to increase with increasing power density and saturates at higher power above 12 W, and the maximum density of 1022 m-3 is achieved at an intermediate flow rate of 20 slm. An optimal condition for O2(a 1Deltag) generation is found that is a balance between power and gas residence. Higher specific energy leads to higher increase of O2(a 1Deltag) density as compared to the O3 density. It is also observed that the O2(a 1Deltag) to O3 density ratio could be controlled by the flow rate from 0.7 to almost 0. The discharge source is used for FCV inactivation on surfaces (in the gas phase) and suspended in solution. Discharge power and treatment time have strong effect on the reduction in virus titer, while exposure distance or flow rate have negligible effect. Humidity plays a major effect on FCV inactivation on surfaces, leading to complete inactivation (>4 log10) within 3 minutes of treatment. FCV inactivation can be explained by O3 in gas phase and RNS in liquid phase. Nonetheless synergistic effects of ROS and RNS cannot be excluded, as similar production rates of O3 and NOx in discharge are determined. The O2(a 1Deltag) density at conditions used for FCV treatment is at least 2 orders of magnitude lower than the ozone density and is not a dominant

Inactivation of carbenicillin by some radioresistant mutant strains

International Nuclear Information System (INIS)

Zahiera, T.S.; Mahmoud, M.I.; Bashandy, A.A.

1990-01-01

Sensitivity test of five bacterial species to carbenicillin was performed microbiologically. The bacterial species were previously isolated from high level radiation environment. All the studied species could either highly decrease the antibiotic activity or even inactivate it completely. Detailed study of the inactivation of carbenicillin by the radioresistant mutant strains B. Laterosporus, B. firmus and M. roseus was performed, in the present study. Using high performace liquid chromatography technique. The gram-positive m. roseus mutant strain seemed to be the most active mutant in degrading the antibiotic. The left over of the antibiotic attained a value of 9% of the original amount after 14 day incubation of the antibiotic with this mutant strain, while the value of the left over reached 36% and 32% after the same period of incubation with the mutants B. laterosporus and B. firmus respectively. In the case of bacillus species, the degradation of the antibiotic started at the same moment when it was added to the bacterial cultures. This fact may indicate that the inactivation of the studied antibiotic by these bacillus species was due to extracellular enzymes extracted rapidly in the surrounding medium. In the case of M. roseus the inactivation process started later. after the addition of the antibiotic to the mutant culture

Dopamine receptor gene expression by enkephalin neurons in rat forebrain

International Nuclear Information System (INIS)

Le Moine, C.; Normand, E.; Guitteny, A.F.; Fouque, B.; Teoule, R.; Bloch, B.

1990-01-01

In situ hybridization experiments were performed with brain sections from normal, control and haloperidol-treated rats to identify and map the cells expressing the D2 dopamine receptor gene. D2 receptor mRNA was detected with radioactive or biotinylated oligonucleotide probes. D2 receptor mRNA was present in glandular cells of the pituitary intermediate lobe and in neurons of the substantia nigra, ventral tegmental area, and forebrain, especially in caudate putamen, nucleus accumbens, olfactory tubercle, and piriform cortex. Hybridization with D2 and preproenkephalin A probes in adjacent sections, as well as combined hybridization with the two probes in the same sections, demonstrated that all detectable enkephalin neurons in the striatum contained the D2 receptor mRNA. Large neurons in caudate putamen, which were unlabeled with the preproenkephalin A probe and which may have been cholinergic, also expressed the D2 receptor gene. Haloperidol treatment (14 or 21 days) provoked an increase in mRNA content for D2 receptor and preproenkephalin A in the striatum. This suggests that the increase in D2 receptor number observed after haloperidol treatment is due to increased activity of the D2 gene. These results indicate that in the striatum, the enkephalin neurons are direct targets for dopamine liberated from mesostriatal neurons

Dopamine receptor gene expression by enkephalin neurons in rat forebrain

Energy Technology Data Exchange (ETDEWEB)

Le Moine, C.; Normand, E.; Guitteny, A.F.; Fouque, B.; Teoule, R.; Bloch, B. (Universite de Bordeaux II (France))

1990-01-01

In situ hybridization experiments were performed with brain sections from normal, control and haloperidol-treated rats to identify and map the cells expressing the D2 dopamine receptor gene. D2 receptor mRNA was detected with radioactive or biotinylated oligonucleotide probes. D2 receptor mRNA was present in glandular cells of the pituitary intermediate lobe and in neurons of the substantia nigra, ventral tegmental area, and forebrain, especially in caudate putamen, nucleus accumbens, olfactory tubercle, and piriform cortex. Hybridization with D2 and preproenkephalin A probes in adjacent sections, as well as combined hybridization with the two probes in the same sections, demonstrated that all detectable enkephalin neurons in the striatum contained the D2 receptor mRNA. Large neurons in caudate putamen, which were unlabeled with the preproenkephalin A probe and which may have been cholinergic, also expressed the D2 receptor gene. Haloperidol treatment (14 or 21 days) provoked an increase in mRNA content for D2 receptor and preproenkephalin A in the striatum. This suggests that the increase in D2 receptor number observed after haloperidol treatment is due to increased activity of the D2 gene. These results indicate that in the striatum, the enkephalin neurons are direct targets for dopamine liberated from mesostriatal neurons.

Role of DNA damage in ultraviolet (313 nm) inactivation of yeasts Saccharomyces cerevisial

International Nuclear Information System (INIS)

Pospelov, M.E.; Ivanova, Eh.V.; Frajkin, G.Ya.

1984-01-01

Relative contribution of photoinhibition of cell respiration and DNA damage to lethal effect, caused by ultraviolet (UV) radiation of 313 m in certain yeast strains Saccharomyces cerevisiae, has been studied. It is shown that cell inactivation is mainly conditioned by DNA photodamage. When studying photoreactivation it has been established, that dimers of pyrimidine bases are the main lethal photoproducts, formed in DNA Under the effect of UV-radiation of 313 nm

Lactobacilli inactivate Chlamydia trachomatis through lactic acid but not H2O2.

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Zheng Gong

Full Text Available Lactobacillus species dominate the microbiome in the lower genital tract of most reproductive-age women. Producing lactic acid and H2O2, lactobacilli are believed to play an important role in prevention of colonization by and growth of pathogens. However, to date, there have been no reported studies characterizing how lactobacilli interact with Chlamydia trachomatis, a leading sexually transmitted bacterium. In this report, we demonstrate inactivation of C. trachomatis infectivity by culture media conditioned by Lactobacillus crispatus, L. gasseri and L. jensenii, known to be dominating organisms in the human vaginal microbiome. Lactobacillus still cultures produced lactic acid, leading to time- and concentration-dependent killing of C. trachomatis. Neutralization of the acidic media completely reversed chlamydia killing. Addition of lactic acid into Lactobacillus-unconditioned growth medium recapitulated the chlamydiacidal activity of conditioned media. The H2O2 concentrations in the still cultures were found to be comparable to those reported for the cervicovaginal fluid, but insufficient to inactivate chlamydiae. Aeration of Lactobacillus cultures by shaking markedly induced H2O2 production, but strongly inhibited Lactobacillus growth and lactic acid production, and thus severely affected acidification, leading to significantly reduced chlamydiacidal efficiency. These observations indicate lactobacilli inactivate chlamydiae primarily through maintaining acidity in a relatively hypoxic environment in the vaginal lumen with limited H2O2, which is consistent with the notion that women with higher vaginal pH are more prone to sexually transmitted C. trachomatis infection. In addition to lactic acid, formic acid and acetic acid also exhibited potent chlamydiacidal activities. Taken together, our findings imply that lowering the vaginal pH through engineering of the vaginal microbiome and other means will make women less susceptible to C

37 CFR 11.11 - Administrative suspension, inactivation, resignation, and readmission.

Science.gov (United States)

2010-07-01

... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Administrative suspension, inactivation, resignation, and readmission. 11.11 Section 11.11 Patents, Trademarks, and Copyrights UNITED... Other Non-Patent Law § 11.11 Administrative suspension, inactivation, resignation, and readmission. (a...

Immunogenicity of UV-inactivated measles virus

International Nuclear Information System (INIS)

Zahorska, R.; Mazur, N.; Korbecki, M.

1978-01-01

By means of the antigen extinction limit test it was shown that a triple dose vaccination of guinea pigs with UV-inactivated measles virus gave better results, than a single dose vaccination which was proved by the very low immunogenicity index. For both vaccination schemes (single and triple) the immune response was only sligthly influenced by a change of dose from 10 5 to 10 6 HadU 50 /ml or by the addition of aluminum adjuvant. In the antigen extinction limit test the antibody levels were determined by two methods (HIT and NT) the results of which were statistically equivalent. The UV-inactivated measles virus was also found to induce hemolysis-inhibiting antibodies. (orig.) [de

The mRNA expression and histological integrity in rat forebrain motor and sensory regions are minimally affected by acrylamide exposure through drinking water

International Nuclear Information System (INIS)

Bowyer, John F.; Latendresse, John R.; Delongchamp, Robert R.; Warbritton, Alan R.; Thomas, Monzy; Divine, Becky; Doerge, Daniel R.

2009-01-01

A study was undertaken to determine whether alterations in the gene expression or overt histological signs of neurotoxicity in selected regions of the forebrain might occur from acrylamide exposure via drinking water. Gene expression at the mRNA level was evaluated by cDNA array and/or RT-PCR analysis in the striatum, substantia nigra and parietal cortex of rat after a 2-week acrylamide exposure. The highest dose tested (maximally tolerated) of approximately 44 mg/kg/day resulted in a significant decreased body weight, sluggishness, and locomotor activity reduction. These physiological effects were not accompanied by prominent changes in gene expression in the forebrain. All the expression changes seen in the 1200 genes that were evaluated in the three brain regions were ≤ 1.5-fold, and most not significant. Very few, if any, statistically significant changes were seen in mRNA levels of the more than 50 genes directly related to the cholinergic, noradrenergic, GABAergic or glutamatergic neurotransmitter systems in the striatum, substantia nigra or parietal cortex. All the expression changes observed in genes related to dopaminergic function were less than 1.5-fold and not statistically significant and the 5HT1b receptor was the only serotonin-related gene affected. Therefore, gene expression changes were few and modest in basal ganglia and sensory cortex at a time when the behavioral manifestations of acrylamide toxicity had become prominent. No histological evidence of axonal, dendritic or neuronal cell body damage was found in the forebrain due to the acrylamide exposure. As well, microglial activation was not present. These findings are consistent with the absence of expression changes in genes related to changes in neuroinflammation or neurotoxicity. Over all, these data suggest that oral ingestion of acrylamide in drinking water or food, even at maximally tolerable levels, induced neither marked changes in gene expression nor neurotoxicity in the motor and

Influenza (flu) vaccine (Inactivated or Recombinant): What you need to know

Science.gov (United States)

... taken in its entirety from the CDC Inactivated Influenza Vaccine Information Statement (VIS) www.cdc.gov/vaccines/hcp/vis/vis-statements/flu.html CDC review information for Inactivated Influenza VIS: ...

Inactivation disinfection property of Moringa Oleifera seed extract: optimization and kinetic studies

Science.gov (United States)

Idris, M. A.; Jami, M. S.; Hammed, A. M.

2017-05-01

This paper presents the statistical optimization study of disinfection inactivation parameters of defatted Moringa oleifera seed extract on Pseudomonas aeruginosa bacterial cells. Three level factorial design was used to estimate the optimum range and the kinetics of the inactivation process was also carried. The inactivation process involved comparing different disinfection models of Chicks-Watson, Collins-Selleck and Homs models. The results from analysis of variance (ANOVA) of the statistical optimization process revealed that only contact time was significant. The optimum disinfection range of the seed extract was 125 mg/L, 30 minutes and 120rpm agitation. At the optimum dose, the inactivation kinetics followed the Collin-Selleck model with coefficient of determination (R2) of 0.6320. This study is the first of its kind in determining the inactivation kinetics of pseudomonas aeruginosa using the defatted seed extract.

Imprinted X chromosome inactivation: evolution of mechanisms in distantly related mammals

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Shafagh A. Waters

2015-03-01

Full Text Available In females, X chromosome inactivation (XCI ensures transcriptional silencing of one of the two Xs (either in a random or imprinted fashion in somatic cells. Comparing this silencing between species has offered insight into different mechanisms of X inactivation, providing clues into the evolution of this epigenetic process in mammals. Long-noncoding RNAs have emerged as a common theme in XCI of therian mammals (eutherian and marsupial. Eutherian X inactivation is regulated by the noncoding RNA product of XIST, within a cis-acting master control region called the X inactivation center (XIC. Marsupials XCI is XIST independent. Instead, XCI is controlled by the long-noncoding RNA Rsx, which appears to be a functional analog of the eutherian XIST gene, insofar that its transcript coats the inactive X and represses activity of genes in cis. In this review we discuss XCI in eutherians, and contrast imprinted X inactivation in mouse and marsupials. We provide particular focus on the evolution of genomic elements that confer the unique epigenetic features that characterize the inactive X chromosome.

Transient inactivation of the paraventricular nucleus of the thalamus enhances cue-induced reinstatement in goal-trackers, but not sign-trackers.

Science.gov (United States)

Kuhn, Brittany N; Klumpner, Marin S; Covelo, Ignacio R; Campus, Paolo; Flagel, Shelly B

2018-04-01

The paraventricular nucleus of the thalamus (PVT) has been shown to mediate cue-motivated behaviors, such as sign- and goal-tracking, as well as reinstatement of drug-seeking behavior. However, the role of the PVT in mediating individual variation in cue-induced drug-seeking behavior remains unknown. This study aimed to determine if inactivation of the PVT differentially mediates cue-induced drug-seeking behavior in sign-trackers and goal-trackers. Rats were characterized as sign-trackers (STs) or goal-trackers (GTs) based on their Pavlovian conditioned approach behavior. Rats were then exposed to 15 days of cocaine self-administration, followed by a 2-week forced abstinence period and then extinction training. Rats then underwent tests for cue-induced reinstatement and general locomotor activity, prior to which they received an infusion of either saline (control) or baclofen/muscimol (B/M) to inactivate the PVT. Relative to control animals of the same phenotype, GTs show a robust increase in cue-induced drug-seeking behavior following PVT inactivation, whereas the behavior of STs was not affected. PVT inactivation did not affect locomotor activity in either phenotype. In GTs, the PVT appears to inhibit the expression of drug-seeking, presumably by attenuating the incentive value of the drug cue. Thus, inactivation of the PVT releases this inhibition in GTs, resulting in an increase in cue-induced drug-seeking behavior. PVT inactivation did not affect cue-induced drug-seeking behavior in STs, suggesting that the role of the PVT in encoding the incentive motivational value of drug cues differs between STs and GTs.

Pulsed dielectric barrier discharge for Bacillus subtilis inactivation in water

Science.gov (United States)

Hernández-Arias, A. N.; Rodríguez-Méndez, B. G.; López-Callejas, R.; Valencia-Alvarado, R.; Mercado-Cabrera, A.; Peña-Eguiluz, R.; Barocio, S. R.; Muñoz-Castro, A. E.; de la Piedad Beneitez, A.

2012-06-01

The inactivation of Bacillus subtilis bacteria in water has been experimentally studied by means of a pulsed dielectric barrier discharge (PDBD) in a coaxial reactor endowed with an alumina dielectric. The plasma source is capable of operating at atmospheric pressure with gas, water or hybrid gas-liquid media at adjustable 25 kV pulses, 30 μs long and at a 500 Hz frequency. In order to evaluate the inactivation efficiency of the system, a set of experiments were designed on the basis of oxygen flow control. The initial data have showed a significant bacterial rate reduction of 103-107 CFU/mL. Additional results proved that applying an oxygen flow for a few seconds during the PDBD treatment inactivates the Bacillus subtilis population with 99.99% effectiveness. As a reference, without gas flow but with the same exposure times, this percentage is reduced to ~90%. The analysis of the relationship between inactivation rate and chemical species in the discharge has been carried out using optical emission spectroscopy as to identifying the main reactive species. Reactive oxygen species such as atomic oxygen and ozone tuned out to be the dominant germicidal species. Some proposed inactivation mechanisms of this technique are discussed.

Pulsed dielectric barrier discharge for Bacillus subtilis inactivation in water

International Nuclear Information System (INIS)

Hernández-Arias, A N; López-Callejas, R; De la Piedad Beneitez, A; Rodríguez-Méndez, B G; Valencia-Alvarado, R; Mercado-Cabrera, A; Peña-Eguiluz, R; Barocio, S R; Muñoz-Castro, A E

2012-01-01

The inactivation of Bacillus subtilis bacteria in water has been experimentally studied by means of a pulsed dielectric barrier discharge (PDBD) in a coaxial reactor endowed with an alumina dielectric. The plasma source is capable of operating at atmospheric pressure with gas, water or hybrid gas-liquid media at adjustable 25 kV pulses, 30 μs long and at a 500 Hz frequency. In order to evaluate the inactivation efficiency of the system, a set of experiments were designed on the basis of oxygen flow control. The initial data have showed a significant bacterial rate reduction of 10 3 -10 7 CFU/mL. Additional results proved that applying an oxygen flow for a few seconds during the PDBD treatment inactivates the Bacillus subtilis population with 99.99% effectiveness. As a reference, without gas flow but with the same exposure times, this percentage is reduced to ∼90%. The analysis of the relationship between inactivation rate and chemical species in the discharge has been carried out using optical emission spectroscopy as to identifying the main reactive species. Reactive oxygen species such as atomic oxygen and ozone tuned out to be the dominant germicidal species. Some proposed inactivation mechanisms of this technique are discussed.

Physiological and morphological characterization of organotypic cocultures of the chick forebrain area MNH and its main input area DMA/DMP.

Science.gov (United States)

Endepols, H; Jungnickel, J; Braun, K

2001-01-01

Cocultures of the learning-relevant forebrain region mediorostral neostriatum and hyperstriatum ventrale (MNH) and its main glutamatergic input area nucleus dorsomedialis anterior thalami/posterior thalami were morphologically and physiologically characterized. Synaptic contacts of thalamic fibers were light- and electron-microscopically detected on MNH neurons by applying the fluorescence tracer DiI-C18(3) into the thalamus part of the coculture. Most thalamic synapses on MNH neurons were symmetric and located on dendritic shafts, but no correlation between Gray-type ultrastructure and dendritic localization was found. Using intracellular current clamp recordings, we found that the electrophysiological properties, such as input resistance, time constant, action potential threshold, amplitude, and duration of MNH neurons, remain stable for over 30 days in vitro. Pharmacological blockade experiments revealed glutamate as the main neurotransmitter of thalamic synapses on MNH neurons, which were also found on inhibitory neurons. High frequency stimulation of thalamic inputs evoked synaptic potentiation in 22% of MNH neurons. The results indicate that DMA/DMP-MNH cocultures, which can be maintained under stable conditions for at least 4 weeks, provide an attractive in vitro model for investigating synaptic plasticity in the avian brain.

Role of Temperature and Suwannee River Natural Organic Matter on Inactivation Kinetics of Rotavirus and Bacteriophage MS2 by Solar Irradiation

KAUST Repository

Romero, Ofelia C.

2011-12-15

Although the sunlight-mediated inactivation of viruses has been recognized as an important process that controls surface water quality, the mechanisms of virus inactivation by sunlight are not yet clearly understood. We investigated the synergistic role of temperature and Suwannee River natural organic matter (SRNOM), an exogenous sensitizer, for sunlight-mediated inactivation of porcine rotavirus and MS2 bacteriophage. Upon irradiation by a full spectrum of simulated sunlight in the absence of SRNOM and in the temperature range of 14-42 °C, high inactivation rate constants, kobs, of MS2 (k obs ≤ 3.8 h-1 or 1-log10 over 0.6 h) and rotavirus (kobs ≤ 11.8 h-1 or ∼1-log10 over 0.2 h) were measured. A weak temperature (14-42 °C) dependence of kobs values was observed for both viruses irradiated by the full sunlight spectrum. Under the same irradiation condition, the presence of SRNOM reduced the inactivation of both viruses due to attenuation of lower wavelengths of the simulated sunlight. For rotavirus and MS2 solutions irradiated by only UVA and visible light in the absence of SRNOM, inactivation kinetics were slow (kobs < 0.3 h-1 or <1-log10 unit reduction over 7 h) and temperature-independent for the range considered. Conversely, under UVA and visible light irradiation and in the presence of SRNOM, temperature-dependent inactivation of MS2 was observed. For rotavirus, the SRNOM-mediated exogenous inactivation was only important at temperatures >33 °C, with low rotavirus kobs values (kobs ≈ 0.2 h-1; 1-log10 unit reduction over 12 h) for the temperature range of 14-33 °C. These kobs values increased to 0.5 h-1 at 43 °C and 1.5 h-1 (1-log10 reduction over 1.6 h) at 50 °C. While SRNOM-mediated exogenous inactivation of MS2 was triggered by singlet oxygen, the presence of hydrogen peroxide was important for rotavirus inactivation in the 40-50 °C range. © 2011 American Chemical Society.

Inactivation of E. Coli in Water Using Photocatalytic, Nanostructured Films Synthesized by Aerosol Routes

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Pratim Biswas

2013-03-01

Full Text Available TiO2 nanostructured films were synthesized by an aerosol chemical vapor deposition (ACVD method with different controlled morphologies: columnar, granular, and branched structures for the photocatalytic inactivation of Escherichia coli (E. coli in water. Effects of film morphology and external applied voltage on inactivation rate were investigated. As-prepared films were characterized using scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffractometry (XRD, and UV-VIS. Photocatalytic and photoelectrochemical inactivation of E. coli using as-prepared TiO2 films were performed under irradiation of UVA light (note: UVA has a low efficiency to inactivate E. coli. Inactivation rate constants for each case were obtained from their respective inactivation curve through a 2 h incubation period. Photocatalytic inactivation rate constants of E. coli are 0.02/min (using columnar films, and 0.08/min (using branched films. The inactivation rate constant for the columnar film was enhanced by 330% by applied voltage on the film while that for the branched film was increased only by 30%. Photocatalytic microbial inactivation rate of the columnar and the branched films were also compared taking into account their different surface areas. Since the majority of the UV radiation that reaches the Earth’s surface is UVA, this study provides an opportunity to use sunlight to efficiently decontaminate drinking water.

Stem-Cell Inactivation on Transplantation of Haemopoietic Cell Suspensions from Genetically Different Donors

Energy Technology Data Exchange (ETDEWEB)

Petrov, R. V. [Institute of Biophysics, Ministry of Public Health of the USSR, Moscow, USSR (Russian Federation)

1969-07-15

The transplantation of a mixture of haemopoietic or lymphoid cells from two genetically different mice into lethally irradiated F{sub 1} recipients results in marked or total inactivation of the colony-forming units of the graft. This phenomenon is observed following transplantation of mixtures of spleen cells or bone-marrow cells from animals of different genotypes: CBA + C57BL, A + CBA, A + C57BL, C3H + C57BL, CBA + (CBA x C57BL) F{sub 1}. Maximum inactivation is observed when lymph-node cells of one genotype are transplanted with spleen or bone-marrow cells of another genotype. Use of non-syngenic kidney cells or lymphoid cells inactivated by irradiation as one component of the mixture shows that inactivation of genetically heterogeneous stem cells requires the participation of viable lymphoid cells. The inactivation phenomenon is also observed with Jerne's method. This shows that inactivation affects not only colony-forming cells but also the immunologically competent precursors of antibody-producing cells. (author)

Inactivation of influenza A virus H1N1 by disinfection process.

Science.gov (United States)

Jeong, Eun Kyo; Bae, Jung Eun; Kim, In Seop

2010-06-01

Because any patient, health care worker, or visitor is capable of transmitting influenza to susceptible persons within hospitals, hospital-acquired influenza has been a clinical concern. Disinfection and cleaning of medical equipment, surgical instruments, and hospital environment are important measures to prevent transmission of influenza virus from hospitals to individuals. This study was conducted to evaluate the efficacy of disinfection processes, which can be easily operated at hospitals, in inactivating influenza A virus H1N1 (H1N1). The effects of 0.1 mol/L NaOH, 70% ethanol, 70% 1-propanol, solvent/detergent (S/D) using 0.3% tri (n-butyl)-phosphate and 1.0% Triton X-100, heat, and ethylene oxide (EO) treatments in inactivating H1N1 were determined. Inactivation of H1N1 was kinetically determined by the treatment of disinfectants to virus solution. Also, a surface test method, which involved drying an amount of virus on a surface and then applying the inactivation methods for 1 minute of contact time, was used to determine the virucidal activity. H1N1 was completely inactivated to undetectable levels in 1 minute of 70% ethanol, 70% 1-propanol, and solvent/detergent treatments in the surface tests as well as in the suspension tests. H1N1 was completely inactivated in 1 minute of 0.1 mol/L NaOH treatment in the suspension tests and also effectively inactivated in the surface tests with the log reduction factor of 3.7. H1N1 was inactivated to undetectable levels within 5 minutes, 2.5 minutes, and 1 minute of heat treatment at 70, 80, and 90 degrees C, respectively in the suspension tests. Also, H1N1 was completely inactivated by EO treatment in the surface tests. Common disinfectants, heat, and EO tested in this study were effective at inactivating H1N1. These results would be helpful in implementing effective disinfecting measures to prevent hospital-acquired infections. Copyright 2010 Association for Professionals in Infection Control and Epidemiology, Inc

Effect of rutin on virus inactivation by AMT in combination with ultraviolet-A irradiation in platelet concentrates

Energy Technology Data Exchange (ETDEWEB)

Yamada, Yoshiko; Abe, Hideki; Ikebuchi, Kenji; Sekiguchi, Sadayoshi [Hokkaido Red Cross Blood Center, Sapporo (Japan)

1999-10-01

Treatment with psoralens and ultraviolet-A (UVA) irradiation have been found to be effective for virus sterilization of platelet concentrates (PCs). We report here a virus inactivation method using a combination of psoralen derivative 4'-aminomethyl-4,5', 8-trimethylpsoralen (AMT) and UVA irradiation (AMT/UVA). Further, we also investigated the effect of rutin, a radical scavenger, on the inactivation of vesicular stomatitis virus (VSV) as a model virus administered in PCs and platelet functions were investigated. Spiked VSV (about 5log{sub 10}) in PCs was inactivated by a combination of AMT (50 {mu}g/ml) and 5.2 J/cm{sup 2} UVA irradiation in the absence of rutin. To obtain equivalent levels of VSV kill in the presence of 0.35 mM rutin, treatment with 13.0 J/cm{sup 2} of UVA irradiation with AMT was performed. When PCs were treated under each condition in which 5log{sub 10} VSV was inactivated by AMT/UVA with or without rutin, platelet aggregation function was maintained for more than 80% of untreated platelets. These findings indicate that the presence of rutin during AMT/UVA treatment conferred no beneficial effect. In addition, overnight storage of PCs with AMT induced 40% loss of platelet aggregation in response to 10{mu}M ADP. The findings suggest that UVA irradiation is required immediately after the addition of AMT. (author)

Inactivation of bacteria via photosensitization of vitamin K3 by UV-A light.

Science.gov (United States)

Xu, Fei; Vostal, Jaroslav G

2014-09-01

This study investigated inactivation of bacteria with ultraviolet light A irradiation in combination with vitamin K3 as a photosensitizer. Six bacteria including Bacillus cereus, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, and Escherichia coli suspended in vitamin K3 aqueous solution were exposed to ultraviolet light A. Five of six bacteria, with the exception of Pseudomonas aeruginosa, were reduced by eight logs with 1600 μM of vitamin K3 and 5.8 J cm(-2) UV-A irradiation. Pseudomonas aeruginosa was reduced by four logs under these conditions. Reactive oxygen species including singlet oxygen, hydroxyl radical and superoxide anion radical were generated in vitamin K3 aqueous solution under UV-A irradiation. These results suggest that vitamin K3 and UV-A irradiation may be effective for bacterial inactivation in environmental and medical applications. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

The Eag domain regulates the voltage-dependent inactivation of rat Eag1 K+ channels.

Directory of Open Access Journals (Sweden)

Ting-Feng Lin

Full Text Available Eag (Kv10 and Erg (Kv11 belong to two distinct subfamilies of the ether-à-go-go K+ channel family (KCNH. While Erg channels are characterized by an inward-rectifying current-voltage relationship that results from a C-type inactivation, mammalian Eag channels display little or no voltage-dependent inactivation. Although the amino (N-terminal region such as the eag domain is not required for the C-type inactivation of Erg channels, an N-terminal deletion in mouse Eag1 has been shown to produce a voltage-dependent inactivation. To further discern the role of the eag domain in the inactivation of Eag1 channels, we generated N-terminal chimeras between rat Eag (rEag1 and human Erg (hERG1 channels that involved swapping the eag domain alone or the complete cytoplasmic N-terminal region. Functional analyses indicated that introduction of the homologous hERG1 eag domain led to both a fast phase and a slow phase of channel inactivation in the rEag1 chimeras. By contrast, the inactivation features were retained in the reverse hERG1 chimeras. Furthermore, an eag domain-lacking rEag1 deletion mutant also showed the fast phase of inactivation that was notably attenuated upon co-expression with the rEag1 eag domain fragment, but not with the hERG1 eag domain fragment. Additionally, we have identified a point mutation in the S4-S5 linker region of rEag1 that resulted in a similar inactivation phenotype. Biophysical analyses of these mutant constructs suggested that the inactivation gating of rEag1 was distinctly different from that of hERG1. Overall, our findings are consistent with the notion that the eag domain plays a critical role in regulating the inactivation gating of rEag1. We propose that the eag domain may destabilize or mask an inherent voltage-dependent inactivation of rEag1 K+ channels.

Studies on disappearance and inactivation of viruses in sewage, 2

International Nuclear Information System (INIS)

Yano, Kazuyoshi; Yabuuchi, Kiyoshi; Taguchi, Fumiaki.

1985-01-01

Methods of inactivating viruses in wastewater were studied. Polio visuses were added to the distilled water until the number of viruses reached 10sup(6.8) TCID 50 /ml, and liquid layer was 2 mm. The inactivation rate of viruses was determined at each time of ultraviolet (U.V.) irradiation (from 0.425 x 10 4 μw/cm 2 to 10.0 x 10 4 μw/cm 2 ). A linear correlation was seen between the inactivation rate of viruses and the time of U.V. irradiation obtained from logarithmic transformation. The irradiation time required for inactivation of 99.9% viruses was 15 sec when U.V. intensity was 10.0 x 10 4 μw/cm 2 and 9.6 min when it was 0.423 x 10 4 μw/cm 2 . When the U.V. intensity was 0.425 x 10 4 μw/cm 2 , the time required for inactivation was dependent on the number of viruses (120 sec in cases of 10sup(3.8) TCID 50 /ml of viruses and 720 sec in cases of 10sup(7.8) TCID 50 /ml of viruses). When viruses were added to the distilled water until the number reached 10sup(5.8) TCID 50 /ml, and the depth of water was designated as 2 mm, 10 cm, and 15 cm, the U.V. permeability was more than 89% at any depth of water, and a sixteen-min U.V. irradiation inactivated more than 99.99% of viruses. When polio viruses were added to triple step-treated water until the number reached 10sup(5.3) TCID 50 /ml, the irradiation time required for inactivation of more than 99.99% was one min when the U.V. intensity was 10.0 x 10 4 μw/cm 2 and 20 min when it was 0.425 x 10 4 μw/cm 2 . (Namekawa, K.)

Efficient Bacteria Inactivation by Ultrasound in Municipal Wastewater

Directory of Open Access Journals (Sweden)

Leonel Ernesto Amabilis-Sosa

2018-04-01

Full Text Available The reuse of treated wastewaters could contribute to reducing water stress. In this research, ultrasound application on bacterial inactivation in municipal wastewater (MWW was evaluated. Total and fecal coliforms were used as standard fecal indicators; volatile suspended solids (VSS were analyzed too. Samples were taken from the effluent of secondary clarifiers. In addition, inactivation tests were carried out on pure cultures of E. coli (EC and B. subtilis (BS. Sonication was performed at 20 kHz, 35% amplitude and 600 W/L for 15, 30 and 45 min. After 15 min of sonication, bacterial density was reduced by 1.85 Log10 MPN/100 mL for EC and 3.16 Log10 CFU/mL for BS. After 30 min, no CFU/mL of BS were observed in MWW and, after 45 min, the reduction of total and fecal coliforms was practically 6.45 Log10 MPN/100mL. Inactivation mechanism was made by cavitation, which causes irreversible damage to the cell wall. Although high bacterial densities were employed, percentages of inactivation >99% were reached at 45 min. This research contributes to the implementation of ultrasound as a disinfection technique with high potential due to its high efficiency without producing byproducts. In fact, the water meets the guidelines for reuse in direct human contact services.

Inactivation of bacteria in sewage sludge by gamma radiation

International Nuclear Information System (INIS)

Pandya, G.A.; Kapila, Smita; Kelkar, V.B.; Negi, Shobha; Modi, V.V.

1987-01-01

The survival of certain bacterial cultures suspended in sewage sludge and exposed to gamma-radiation was studied. The inactivation patterns of most of the organisms were significantly different when irradiation was performed using sewage samples collected in the summer and monsoon seasons. The summer sample collected from the anaerobic digester afforded significant protection to both Gram negative and Gram positive organisms. This was evident by the increase in dose required to bring about a 6 log cycle reduction in viable count of the bacterial cultures, when suspended in sewage samples instead of phosphate buffer. The observations made using monsoon digester samples were quite different. This sewage sludge greatly enhanced inactivation by gamma-radiation in most cases. The effects of certain chemicals on the inactivation patterns of two organisms - Salmonella typhi and Shigella flexneri - were examined. Arsenate, mercury and lead salts sensitised S. typhi, while barium acetate and sodium sulphide protected this culture against gamma-radiation. In the case of Sh. flexneri, barium acetate and iodacetamide proved to be radioprotectors. The effects of some chemicals on the inactivation pattern of Sh. flexneri cells irradiated in sludge are also discussed. (author)

Evaluation of Chlorine Treatment Levels for Inactivation of Human Norovirus and MS2 Bacteriophage during Sewage Treatment.

Science.gov (United States)

Kingsley, David H; Fay, Johnna P; Calci, Kevin; Pouillot, Régis; Woods, Jacquelina; Chen, Haiqiang; Niemira, Brendan A; Van Doren, Jane M

2017-12-01

This study examined the inactivation of human norovirus (HuNoV) GI.1 and GII.4 by chlorine under conditions mimicking sewage treatment. Using a porcine gastric mucin-magnetic bead (PGM-MB) assay, no statistically significant loss in HuNoV binding (inactivation) was observed for secondary effluent treatments of ≤25 ppm total chlorine; for both strains, 50 and 100 ppm treatments resulted in ≤0.8-log 10 unit and ≥3.9-log 10 unit reductions, respectively. Treatments of 10, 25, 50, and 100 ppm chlorine inactivated 0.31, 1.35, >5, and >5 log 10 units, respectively, of the norovirus indicator MS2 bacteriophage. Evaluation of treatment time indicated that the vast majority of MS2 and HuNoV inactivation occurred in the first 5 min for 0.2-μm-filtered, prechlorinated secondary effluent. Free chlorine measurements of secondary effluent seeded with MS2 and HuNoV demonstrated substantial oxidative burdens. With 25, 50, and 100 ppm treatments, free chlorine levels after 5 min of exposure ranged from 0.21 to 0.58 ppm, from 0.28 to 16.7 ppm, and from 11.6 to 53 ppm, respectively. At chlorine treatment levels of >50 ppm, statistically significant differences were observed between reductions for PGM-MB-bound HuNoV (potentially infectious) particles and those for unbound (noninfectious) HuNoV particles or total norovirus particles. While results suggested that MS2 and HuNoV (measured as PGM-MB binding) behave similarly, although not identically, both have limited susceptibility to chlorine treatments of ≤25 ppm total chlorine. Since sewage treatment is performed at ≤25 ppm total chlorine, targeting free chlorine levels of 0.5 to 1.0 ppm, these results suggest that traditional chlorine-based sewage treatment does not inactivate HuNoV efficiently. IMPORTANCE HuNoV is ubiquitous in sewage. A receptor binding assay was used to assess inactivation of HuNoV by chlorine-based sewage treatment, given that the virus cannot be routinely propagated in vitro Results reported here

Active-site-directed inactivation of Aspergillus oryzae beta-galactosidase with beta-D-galactopyranosylmethyl-p-nitrophenyltriazene.

Science.gov (United States)

Mega, T; Nishijima, T; Ikenaka, T

1990-04-01

beta-D-Galactopyranosylmethyl-p-nitrophenyltriazene (beta-GalMNT), a specific inhibitor of beta-galactosidase, was isolated as crystals by HPLC and its chemical and physicochemical characteristics were examined. Aspergillus oryzae beta-galactosidase was inactivated by the compound. We studied the inhibition mechanism in detail. The inhibitor was hydrolyzed by the enzyme to p-nitroaniline and an active intermediate (beta-galactopyranosylmethyl carbonium or beta-galactopyranosylmethyldiazonium), which inactivated the enzyme. The efficiency of inactivation of the enzyme (the ratio of moles of inactivated enzyme to moles of beta-GalMNT hydrolyzed by the enzyme) was 3%; the efficiency of Escherichia coli beta-galactosidase was 49%. In spite of the low efficiency, the rate of inactivation of A. oryzae enzyme was not very different from that of the E. coli enzyme, because the former hydrolyzed beta-GalMNT faster than the latter did. A. oryzae beta-galactosidase was also inactivated by p-chlorophenyl, p-tolyl, and m-nitrophenyl derivatives of beta-galactopyranosylmethyltriazene. However, E. coli beta-galactosidase was not inactivated by these triazene derivatives. The results showed that the inactivation of A. oryzae and E. coli beta-galactosidases by beta-GalMNT was an enzyme-activated and active-site-directed irreversible inactivation. The possibility of inactivation by intermediates produced nonenzymatically was ruled out for E. coli, but not for the A. oryzae enzyme.

Overexpression of the NR2A subunit in the forebrain impairs long-term social recognition and non-social olfactory memory.

Science.gov (United States)

Jacobs, S A; Tsien, J Z

2014-04-01

Animals must recognize and remember conspecifics and potential mates, and distinguish these animals from potential heterospecific competitors and predators. Despite its necessity, aged animals are known to exhibit impaired social recognition memory. As the brain ages, the ratio of NR2A:NR2B in the brain increases over time and has been postulated to underlie the cognitive decline observed during the aging process. Here, we test the hypothesis that an increased NR2A:NR2B subunit ratio underlies long-term social recognition memory. Using transgenic overexpression of NR2A in the forebrain regions, we investigated the ability of these mice to learn and remember male and female conspecifics, mice of another strain and animals of another rodent species, the rat. Furthermore, due to the importance of olfaction in social recognition, we tested the olfactory memory in the NR2A transgenic mice. Our series of behavioral experiments revealed significant impairments in the NR2A transgenic mice in long-term social memory of both male and female conspecifics. Additionally, the NR2A transgenic mice are unable to recognize mice of another strain or rats. The NR2A transgenic mice also exhibited long-term memory impairments in the olfactory recognition task. Taken together, our results provide evidence that an increased NR2A:NR2B ratio in the forebrain leads to reduced long-term memory function, including the ethologically important memories such as social recognition and olfactory memory.

Use of In Situ-Generated Dimethyldioxirane for Inactivation of Biological Agents

National Research Council Canada - National Science Library

Wallace, William H; Bushway, Karen E; Miller, Susan D; Delcomyn, Carrie A; Renard, Jean J; Henley, Michael V

2005-01-01

...) at neutral pH, was investigated for inactivation of biological warfare agent simulants. The DMDO solution inactivated bacterial spores, fungal spores, vegetative bacterial cells, viruses, and protein by 7 orders of magnitude in less than 10 min...

High pressure processing's potential to inactivate norovirus and other fooodborne viruses

Science.gov (United States)

High pressure processing (HPP) can inactivate human norovirus. However, all viruses are not equally susceptible to HPP. Pressure treatment parameters such as required pressure levels, initial pressurization temperatures, and pressurization times substantially affect inactivation. How food matrix ...

Method of inactivating reproducible forms of mycoplasma in biological preparations

International Nuclear Information System (INIS)

Veber, P.; Jurmanova, K.; Lesko, J.; Hana, L.; Veber, V.

1978-01-01

Inactivation of mycoplasms in biological materials was achieved using gamma radiation with a dose rate of 1x10 4 to 5x10 6 rads/h for 1 to 250 hours. The technique is advantageous for allowing the inactivation of the final form of products (tablets, vaccines, etc.). (J.P.)

Antigenic characterization of a formalin-inactivated poliovirus vaccine derived from live-attenuated Sabin strains.

Science.gov (United States)

Tano, Yoshio; Shimizu, Hiroyuki; Martin, Javier; Nishimura, Yorihiro; Simizu, Bunsiti; Miyamura, Tatsuo

2007-10-10

A candidate inactivated poliovirus vaccine derived from live-attenuated Sabin strains (sIPV), which are used in the oral poliovirus vaccine (OPV), was prepared in a large-production scale. The modification of viral antigenic epitopes during the formalin inactivation process was investigated by capture ELISA assays using type-specific and antigenic site-specific monoclonal antibodies (MoAbs). The major antigenic site 1 was modified during the formalin inactivation of Sabin 1. Antigenic sites 1-3 were slightly modified during the formalin inactivation of Sabin 2 strain. Sites 1 and 3 were altered on inactivated Sabin 3 virus. These alterations were different to those shown by wild-type Saukett strain, used in conventional IPV (cIPV). It has been previously reported that type 1 sIPV showed higher immunogenicity to type 1 cIPV whereas types 2 and 3 sIPV induced lower level of immunogenicity than their cIPV counterparts. Our results suggest that the differences in epitope structure after formalin inactivation may account, at least in part, for the observed differences in immunogenicity between Sabin and wild-type inactivated poliovaccines.

Chlorine inactivation of fungal spores on cereal grains.

Science.gov (United States)

Andrews, S; Pardoel, D; Harun, A; Treloar, T

1997-04-01

Although 0.4% chlorine for 2 min has been recommended for surface disinfection of food samples before direct plating for fungal enumeration, this procedure may not be adequate for highly contaminated products. The effectiveness of a range of chlorine solutions was investigated using barley samples artificially contaminated with four different concentrations of Aspergillus flavus. A. niger, A. ochraceus, Eurotium repens, Penicillium brevicompactum P. chrysogenum and Cladosporium cladosporioides. At initial contamination levels greater than 10(4)/g, 0.4% chlorine did not inactivate sufficient spores to produce less than 20% contamination. Of the test fungi, ascospores of E. repens were the most resistant to chlorine inactivation, whereas the conidia of C. cladosporioides were the most sensitive. Rinsing the samples with 70% ethanol improved the effectiveness of the recommended surface disinfection procedure. However, some ethanol appears to permeate into the grains and may inactivate sensitive internal fungi, although a minimal effect only was observed on wheat infected with Alternaria.

Distinct Temporal Coordination of Spontaneous Population Activity between Basal Forebrain and Auditory Cortex

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Josue G. Yague

2017-09-01

Full Text Available The basal forebrain (BF has long been implicated in attention, learning and memory, and recent studies have established a causal relationship between artificial BF activation and arousal. However, neural ensemble dynamics in the BF still remains unclear. Here, recording neural population activity in the BF and comparing it with simultaneously recorded cortical population under both anesthetized and unanesthetized conditions, we investigate the difference in the structure of spontaneous population activity between the BF and the auditory cortex (AC in mice. The AC neuronal population show a skewed spike rate distribution, a higher proportion of short (≤80 ms inter-spike intervals (ISIs and a rich repertoire of rhythmic firing across frequencies. Although the distribution of spontaneous firing rate in the BF is also skewed, a proportion of short ISIs can be explained by a Poisson model at short time scales (≤20 ms and spike count correlations are lower compared to AC cells, with optogenetically identified cholinergic cell pairs showing exceptionally higher correlations. Furthermore, a smaller fraction of BF neurons shows spike-field entrainment across frequencies: a subset of BF neurons fire rhythmically at slow (≤6 Hz frequencies, with varied phase preferences to ongoing field potentials, in contrast to a consistent phase preference of AC populations. Firing of these slow rhythmic BF cells is correlated to a greater degree than other rhythmic BF cell pairs. Overall, the fundamental difference in the structure of population activity between the AC and BF is their temporal coordination, in particular their operational timescales. These results suggest that BF neurons slowly modulate downstream populations whereas cortical circuits transmit signals on multiple timescales. Thus, the characterization of the neural ensemble dynamics in the BF provides further insight into the neural mechanisms, by which brain states are regulated.

Inactivation of alcohol dehydrogenase (ADH) by ferryl derivatives of human hemoglobin.

Science.gov (United States)

Kowalczyk, Aleksandra; Puchała, Mieczysław; Wesołowska, Katarzyna; Serafin, Eligiusz

2007-01-01

In this paper, inactivation of alcohol dehydrogenase (ADH) by products of reactions of H2O2 with metHb has been studied. Inactivation of the enzyme was studied in two systems corresponding to two kinetic stages of the reaction. In the first system H2O2 was added to the mixture of metHb and ADH [the (metHb+ADH)+H2O2] system (ADH was present in the system since the moment of addition of H2O2 i. e. since the very beginning of the reaction of metHb with H2O2). In the second system ADH was added to the system 5 min after the initiation of the reaction of H2O2 with metHb [the (metHb+H2O2)5 min+ADH] system. In the first case all the products of reaction of H2O2 with metHb (non-peroxyl and peroxyl radicals and non-radical products, viz. hydroperoxides and *HbFe(IV)=O) could react with the enzyme causing its inactivation. In the second system, enzyme reacted almost exclusively with non-radical products (though a small contribution of reactions with peroxyl radicals cannot be excluded). ADH inactivation was observed in both system. Hydrogen peroxide alone did not inactivate ADH at the concentrations employed evidencing that enzyme inactivation was due exclusively to products of reaction of H2O2 with metHb. The rate and extent of ADH inactivation were much higher in the first than in the second system. The dependence of ADH activity on the time of incubation with ferryl derivatives of Hb can be described by a sum of three exponentials in the first system and two exponentials in the second system. Reactions of appropriate forms of the ferryl derivatives of hemoglobin have been tentatively ascribed to these exponentials. The extent of the enzyme inactivation in the second system was dependent on the proton concentration, being at the highest at pH 7.4 and negligible at pH 6.0. The reaction of H2O2 with metHb resulted in the formation of cross-links of Hb subunits (dimers and trimers). The amount of the dimers formed was much lower in the first system i. e. when the radical

Inactivation of viruses in labile blood derivatives. II. Physical methods

International Nuclear Information System (INIS)

Horowitz, B.; Wiebe, M.E.; Lippin, A.; Vandersande, J.; Stryker, M.H.

1985-01-01

The thermal inactivation of viruses in labile blood derivatives was evaluated by addition of marker viruses (VSV, Sindbis, Sendai, EMC) to anti-hemophilic factor (AHF) concentrates. The rate of virus inactivation at 60 degrees C was decreased by at least 100- to 700-fold by inclusion of 2.75 M glycine and 50 percent sucrose, or 3.0 M potassium citrate, additives which contribute to retention of protein biologic activity. Nonetheless, at least 10(4) infectious units of each virus was inactivated within 10 hours. Increasing the temperature from 60 to 70 or 80 degrees C caused a 90 percent or greater loss in AHF activity. An even greater decline in the rate of virus inactivation was observed on heating AHF in the lyophilized state, although no loss in AHF activity was observed after 72 hours of heating at 60 degrees C. Several of the proteins present in lyophilized AHF concentrates displayed an altered electrophoretic mobility as a result of exposure to 60 degrees C for 24 hours. Exposure of lyophilized AHF to irradiation from a cobalt 60 source resulted in an acceptable yield of AHF at 1.0, but not at 2.0, megarads. At 1 megarad, greater than or equal to 6.0 logs of VSV and 3.3 logs of Sindbis virus were inactivated

Efficiency of superoxide anions in the inactivation of selected dehydrogenases

International Nuclear Information System (INIS)

Rodacka, Aleksandra; Serafin, Eligiusz; Puchala, Mieczyslaw

2010-01-01

The most ubiquitous of the primary reactive oxygen species, formed in all aerobes, is the superoxide free radical. It is believed that the superoxide anion radical shows low reactivity and in oxidative stress it is regarded mainly as an initiator of more reactive species such as · OH and ONOO - . In this paper, the effectiveness of inactivation of selected enzymes by radiation-generated superoxide radicals in comparison with the effectiveness of the other products of water radiolysis is examined. We investigate three enzymes: glyceraldehyde-3-phosphate dehydrogenase (GAPDH), alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH). We show that the direct contribution of the superoxide anion radical to GAPDH and ADH inactivation is significant. The effectiveness of the superoxide anion in the inactivation of GAPDH and ADG was only 2.4 and 2.8 times smaller, respectively, in comparison with hydroxyl radical. LDH was practically not inactivated by the superoxide anion. Despite the fact that the studied dehydrogenases belong to the same class of enzymes (oxidoreductases), all have a similar molecular weight and are tetramers, their susceptibility to free-radical damage varies. The differences in the radiosensitivity of the enzymes are not determined by the basic structural parameters analyzed. A significant role in inactivation susceptibility is played by the type of amino acid residues and their localization within enzyme molecules.

Efficiency of superoxide anions in the inactivation of selected dehydrogenases

Energy Technology Data Exchange (ETDEWEB)

Rodacka, Aleksandra, E-mail: olakow@biol.uni.lodz.p [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, 90-237 Lodz (Poland); Serafin, Eligiusz, E-mail: serafin@biol.uni.lodz.p [Laboratory of Computer and Analytical Techniques, University of Lodz, Banacha 12/16, 90-237 Lodz (Poland); Puchala, Mieczyslaw, E-mail: puchala@biol.uni.lodz.p [Department of Molecular Biophysics, University of Lodz, Banacha 12/16, 90-237 Lodz (Poland)

2010-09-15

The most ubiquitous of the primary reactive oxygen species, formed in all aerobes, is the superoxide free radical. It is believed that the superoxide anion radical shows low reactivity and in oxidative stress it is regarded mainly as an initiator of more reactive species such as {sup {center_dot}}OH and ONOO{sup -}. In this paper, the effectiveness of inactivation of selected enzymes by radiation-generated superoxide radicals in comparison with the effectiveness of the other products of water radiolysis is examined. We investigate three enzymes: glyceraldehyde-3-phosphate dehydrogenase (GAPDH), alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH). We show that the direct contribution of the superoxide anion radical to GAPDH and ADH inactivation is significant. The effectiveness of the superoxide anion in the inactivation of GAPDH and ADG was only 2.4 and 2.8 times smaller, respectively, in comparison with hydroxyl radical. LDH was practically not inactivated by the superoxide anion. Despite the fact that the studied dehydrogenases belong to the same class of enzymes (oxidoreductases), all have a similar molecular weight and are tetramers, their susceptibility to free-radical damage varies. The differences in the radiosensitivity of the enzymes are not determined by the basic structural parameters analyzed. A significant role in inactivation susceptibility is played by the type of amino acid residues and their localization within enzyme molecules.

Acute Vhl gene inactivation induces cardiac HIF-dependent erythropoietin gene expression.

Directory of Open Access Journals (Sweden)

Marta Miró-Murillo

Full Text Available Von Hippel Lindau (Vhl gene inactivation results in embryonic lethality. The consequences of its inactivation in adult mice, and of the ensuing activation of the hypoxia-inducible factors (HIFs, have been explored mainly in a tissue-specific manner. This mid-gestation lethality can be also circumvented by using a floxed Vhl allele in combination with an ubiquitous tamoxifen-inducible recombinase Cre-ER(T2. Here, we characterize a widespread reduction in Vhl gene expression in Vhl(floxed-UBC-Cre-ER(T2 adult mice after dietary tamoxifen administration, a convenient route of administration that has yet to be fully characterized for global gene inactivation. Vhl gene inactivation rapidly resulted in a marked splenomegaly and skin erythema, accompanied by renal and hepatic induction of the erythropoietin (Epo gene, indicative of the in vivo activation of the oxygen sensing HIF pathway. We show that acute Vhl gene inactivation also induced Epo gene expression in the heart, revealing cardiac tissue to be an extra-renal source of EPO. Indeed, primary cardiomyocytes and HL-1 cardiac cells both induce Epo gene expression when exposed to low O(2 tension in a HIF-dependent manner. Thus, as well as demonstrating the potential of dietary tamoxifen administration for gene inactivation studies in UBC-Cre-ER(T2 mouse lines, this data provides evidence of a cardiac oxygen-sensing VHL/HIF/EPO pathway in adult mice.

Inactivation of the Infralimbic but Not the Prelimbic Cortex Impairs Consolidation and Retrieval of Fear Extinction

Science.gov (United States)

Laurent, Vincent; Westbrook, R. Frederick

2009-01-01

Rats were subjected to one or two cycles of context fear conditioning and extinction to study the roles of the prelimbic cortex (PL) and infralimbic cortex (IL) in learning and relearning to inhibit fear responses. Inactivation of the PL depressed fear responses across the first or second extinction but did not impair learning or relearning fear…

Investigation of optimum ohmic heating conditions for inactivation of Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes in apple juice.

Science.gov (United States)

Park, Il-Kyu; Ha, Jae-Won; Kang, Dong-Hyun

2017-05-19

Control of foodborne pathogens is an important issue for the fruit juice industry and ohmic heating treatment has been considered as one of the promising antimicrobial interventions. However, to date, evaluation of the relationship between inactivation of foodborne pathogens and system performance efficiency based on differing soluble solids content of apple juice during ohmic heating treatment has not been well studied. This study aims to investigate effective voltage gradients of an ohmic heating system and corresponding sugar concentrations (°Brix) of apple juice for inactivating major foodborne pathogens (E. coli O157:H7, S. Typhimurium, and L. monocytogenes) while maintaining higher system performance efficiency. Voltage gradients of 30, 40, 50, and 60 V/cm were applied to 72, 48, 36, 24, and 18 °Brix apple juices. At all voltage levels, the lowest heating rate was observed in 72 °Brix apple juice and a similar pattern of temperature increase was shown in18-48 °Brix juice samples. System performance coefficients (SPC) under two treatment conditions (30 V/cm in 36 °Brix or 60 V/cm in 48 °Brix juice) were relatively greater than for other combinations. Meanwhile, 5-log reductions of the three foodborne pathogens were achieved after treatment for 60 s in 36 °Brix at 30 V/cm, but this same reduction was observed in 48 °Brix juice at 60 V/cm within 20 s without affecting product quality. With respect to both bactericidal efficiency and SPC values, 60 V/cm in 48 °Brix was the most effective ohmic heating treatment combination for decontaminating apple juice concentrates.

Inactivation of γ-aminobutyric acid aminotransferase by γ-ethynyl- and γ-vinyl GABA

International Nuclear Information System (INIS)

Silverman, R.B.; Burke, J.R.; Nanavati, S.M.

1989-01-01

γ-Ethynyl- and γ-vinyl GABA (vigabatrin) are anticonvulsant agents that have been shown to be mechanism-based inactivators of γ-aminobutyric acid aminotransferase (GABA-T). The inactivation mechanisms of these compounds have been investigated. Inactivation of GABA-T by [ 3 H]γ-ethynyl GABA led to the incorporation of 1.0 equiv of 3 H into the enzyme which is not released by enzyme denaturation. Inactivation by γ-ethynyl GABA of GABA-T reconstituted with [ 3 H]PLP followed by denaturation resulted in release of 3 H as PLP. Eight different possible adducts are consistent with that result. Experiments have been carried out to differentiate these possibilities. Similar studies have been carried out with γ-vinyl GABA. Inactivation by [ 14 C]γ-vinyl GABA resulted in the incorporation of 1.0 equiv of 14 C per active site. Unlike the case with γ-ethynyl GABA, γ-vinyl GABA inactivation of GABA-T reconstituted with [ 3 H]PLP followed by denaturation resulted in release of 3 H as PMP

Inactivation of catalase by free radicals derived from oxygen via gamma radiolysis

International Nuclear Information System (INIS)

Malhaire, J.P.; Gardes-Albert, M.; Ferradini, C.; Sabourault, D.; Ribiere, C.

1991-01-01

The inactivation of catalase (10 -5 mol/l) by OH· or OH·/O 2 - · free radicals, at pH 7.4, has been investigated using γ radiolysis with doses up to 9000 Gy. Maxima initial G-values of catalase inactivation have been determined. These values are inferior to those of the free radicals OH· and O 2 - · produced by water radiolysis. Nevertheless, the presence of O 2 /O 2 - · enhances the inactivation due to OH· radicals. The general shape of the inactivation curves as a function of the radiation dose is biphasic: an initial rapid phase (from 0 to ∼ 500 Gy) followed by a slow phase (from ∼ 500 to 9000 Gy). The addition of H 2 O 2 at the beginning of irradiation decreases the inactivation yield by OH· radicals. This phenomenon could be due to the formation of compound-I (catalase-H 2 O 2 ) which would be less sensitive towards OH· radicals than catalase. In the presence of 0.1 mol/l ethanol, catalase (5 x 10 -6 mol/l) is not inactived by O 2 - · and RO 2 · (from ethanol) radicals for an irradiation dose of 2000 Gy, implying a complete protecting effect by ethanol [fr

Virus inactivation studies using ion beams, electron and gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Smolko, Eduardo E. [Laboratorio de Polimeros, Grupo Aplicaciones Industriales, Unidad de Aplicaciones Tecnologicas y Agropecuarias, Centro Atomico Ezeiza, Comision Nacional de Energia Atomica, Pbro. Juan Gonzalez y Aragon 15, C.P. B1802AYA Ezeiza, Buenos Aires (Argentina)]. E-mail: smolko@cae.cnea.gov.ar; Lombardo, Jorge H. [Biotech S.A., C.P. 1754 Buenos Aires (Argentina)

2005-07-01

Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle ({alpha}, d and ss) and {gamma} irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D{sub 37} dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule.

Virus inactivation studies using ion beams, electron and gamma irradiation

International Nuclear Information System (INIS)

Smolko, Eduardo E.; Lombardo, Jorge H.

2005-01-01

Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle (α, d and ss) and γ irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D 37 dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule

X-ray inactivation and reactivation characteristics of the phage 'kappa'

International Nuclear Information System (INIS)

Bhattacharyya, S.C.; Samad, S.A.; Mandal, J.C.; Chatterjee, S.N.

1991-01-01

Vibrio cholerae temperate phage 'kappa' was inactivated by X-ray (60 kV) in a dose dependent manner, the inactivation dose leading to 37% survival (D 37 ) in PBS, pH 7.4 being 0.36 kGy. The phages were significantly protected against X-ray irradiation when histidine or cysteine or both were present in PBS or when phages were irradiated in nutrient broth. The maximum protection was offered when histidine (10.0 nM) and cysteine (10.0 nM) were both present in PBS (dose enhancement factor being 4.17). The X-irradiated 'kappa' phages also underwent a small but significant Weigle reactivation and also Weigle mutagenesis in the UV-irradiated V. cholerae host H218Sm r . The Weigle factor (WF) or the frequency of clear plaque mutants increased with increasing UV dose, attained a maximum at the UV dose of 2.4 Jm -2 and thereafter decreased gradually with further increase of UV dose. The X-ray dose (D)-survival (S) curves could be empirically described by the equation S=exp-(aD+bD 2 ) where 'a' and 'b' are constants depending on the irradiation conditions and good agreement between the theoretical curves and experimental data was obtained. (author). 1 5 refs., 2 fig., 1 tab

Effects of High Pressure on Bacillus licheniformis Spore Germination and Inactivation.

Science.gov (United States)

Borch-Pedersen, Kristina; Mellegård, Hilde; Reineke, Kai; Boysen, Preben; Sevenich, Robert; Lindbäck, Toril; Aspholm, Marina

2017-07-15

Bacillus and Clostridium species form spores, which pose a challenge to the food industry due to their ubiquitous nature and extreme resistance. Pressurization at 300 MPa likely triggers germination by opening dipicolinic acid (DPA) channels present in the inner membrane of the spores. In this work, we expose spores of Bacillus licheniformis , a species associated with food spoilage and occasionally with food poisoning, to high pressure (HP) for holding times of up to 2 h. By using mutant spores lacking one or several GRs, we dissect the roles of the GerA, Ynd, and GerK GRs in moderately HP (mHP; 150 MPa)-induced spore germination. We show that Ynd alone is sufficient for efficient mHP-induced spore germination. GerK also triggers germination with mHP, although at a reduced germination rate compared to that of Ynd. GerA stimulates mHP-induced germination but only in the presence of either the intact GerK or Ynd GR. These results suggests that the effectiveness of the individual GRs in mHP-induced germination differs from their effectiveness in nutrient-induced germination, where GerA plays an essential role. In contrast to Bacillus subtilis spores, treatment with very HP (vHP) of 550 MPa at 37°C did not promote effective germination of B. licheniformis spores. However, treatment with vHP in combination with elevated temperatures (60°C) gave a synergistic effect on spore germination and inactivation. Together, these results provide novel insights into how HP affects B. licheniformis spore germination and inactivation and the role of individual GRs in this process. IMPORTANCE Bacterial spores are inherently resistant to food-processing regimes, such as high-temperature short-time pasteurization, and may therefore compromise food durability and safety. The induction of spore germination facilitates subsequent inactivation by gentler processing conditions that maintain the sensory and nutritional qualities of the food. High-pressure (HP) processing is a nonthermal

Inactivation of bacteria in sewage sludge by ionizing radiation, heat, and thermoradiation

International Nuclear Information System (INIS)

Brandon, J.R.; Langley, S.L.

1976-01-01

For purposes of animal feeding or fertilizer usage on edible crops, sewage sludge must be free of pathogenic organisms. Bacterial inactivation by a combination of heat and irradiation is shown to be effective. These results must be viewed in conjunction with those from studies of parasite egg inactivation, virus inactivation, and physical-chemical benefits in order to make a fair assessment of the value of the thermoradiation treatment compared to other possible sludge treatment processes

Relationship between sublethal injury and inactivation of yeast cells by the combination of sorbic acid and pulsed electric fields.

Science.gov (United States)

Somolinos, M; García, D; Condón, S; Mañas, P; Pagán, R

2007-06-01

The objective of this study was to investigate the occurrence of sublethal injury after the pulsed-electric-field (PEF) treatment of two yeasts, Dekkera bruxellensis and Saccharomyces cerevisiae, as well as the relation of sublethal injury to the inactivating effect of the combination of PEF and sorbic acid. PEF caused sublethal injury in both yeasts: more than 90% of surviving D. bruxellensis cells and 99% of surviving S. cerevisiae cells were sublethally injured after 50 pulses at 12 kV/cm in buffer at pHs of both 7.0 and 4.0. The proportion of sublethally injured cells reached a maximum after 50 pulses at 12.0 kV/cm (S. cerevisiae) or 16.5 kV/cm (D. bruxellensis), and it kept constant or progressively decreased at greater electric field strengths and with longer PEF treatments. Sublethally PEF-injured cells showed sensitivity to the presence of sorbic acid at a concentration of 2,000 ppm. A synergistic inactivating effect of the combination of PEF and sorbic acid was observed. Survivors of the PEF treatment were progressively inactivated in the presence of 2,000 ppm of sorbic acid at pH 3.8, with the combined treatments achieving more than log10 5 cycles of dead cells under the conditions investigated. This study has demonstrated the occurrence of sublethal injury after exposure to PEF, so yeast inactivation by PEF is not an all-or-nothing event. The combination of PEF and sorbic acid has proven to be an effective method to achieve a higher level of yeast inactivation. This work contributes to the knowledge of the mechanism of microbial inactivation by PEF, and it may be useful for improving food preservation by PEF technology.

Light-driven photosensitizer uptake increases Candida albicans photodynamic inactivation.

Science.gov (United States)

Romano, Renan A; Pratavieira, Sebastião; Silva, Ana P da; Kurachi, Cristina; Guimarães, Francisco E G

2017-11-01

Photodynamic Inactivation (PDI) is based on the use of a photosensitizer (PS) and light that results mainly in the production of reactive oxygen species, aiming to produce microorganism cell death. PS incubation time and light dose are key protocol parameters that influence PDI response; the correct choice of them can increase the efficiency of inactivation. The results of this study show that a minor change in the PDI protocol, namely light-driven incubation leads to a higher photosensitizer and more uniform cell uptake inside the irradiated zone. Furthermore, as the uptake increases, the damage caused by PDI also increases. The proposed light-driven incubation prior to the inactivation illumination dose has advantages when compared to the traditional PDI treatments since it can be more selective and effective. Using a violet light as pre-illumination (light-driven incubation) source and a red-light system as PDI source, it was possible to demonstrate that when compared to the traditional protocol of dark incubation, the pre-illuminated cell culture showed an inactivation increase of 7 log units. These in vitro results performed in Candida albicans cells may result in the introduction of a new protocol for PDI. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inactivation of acetylcholinesterase by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride.

Science.gov (United States)

Zang, Lun-Yi; Misra, Hara P

2003-12-01

The neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been shown to reversibly inhibit the activity of acetylcholinesterase. The inactivation of the enzyme was detected by monitoring the accumulation of yellow color produced from the reaction between thiocholine and dithiobisnitrobenzoate ion. The kinetic parameter, Km for the substrate (acetylthiocholine), was found to be 0.216 mM and Ki for MPTP inactivation of acetylcholinesterase was found to be 2.14 mM. The inactivation of enzyme by MPTP was found to be dose-dependent. It was found that MPTP is neither a substrate of AChE nor the time-dependent inactivator. The studies of reaction kinetics indicate the inactivation of AChE to be a linear mixed-type inhibition. The dilution assays indicate that MPTP is a reversible inhibitor for AChE. These data suggest that once MPTP enters the basal ganglia of the brain, it can inactivate the acetylcholinesterase enzyme and thereby increase the acetylcholine level in the basal ganglia of brain, leading to potential cell dysfunction. It appears that the nigrostriatal toxicity by MPTP leading to Parkinson's disease-like syndrome may, in part, be mediated via the acetylcholinesterase inactivation.

Urease from Helicobacter pylori is inactivated by sulforaphane and other isothiocyanates

Science.gov (United States)

Fahey, Jed W.; Stephenson, Katherine K.; Wade, Kristina L.; Talalay, Paul

2013-01-01

Infections by Helicobacter pylori are very common, causing gastroduodenal inflammation including peptic ulcers, and increasing the risk of gastric neoplasia. The isothiocyanate (ITC) sulforaphane [SF; 1-isothiocyanato-4-(methylsulfinyl)butane] derived from edible crucifers such as broccoli is potently bactericidal against Helicobacter, including antibiotic-resistant strains, suggesting a possible dietary therapy. Gastric H. pylori infections express high urease activity which generates ammonia, neutralizes gastric acidity, and promotes inflammation. The finding that SF inhibits (inactivates) urease (jack bean and Helicobacter) raised the issue of whether these properties might be functionally related. The rates of inactivation of urease activity depend on enzyme and SF concentrations and show first order kinetics. Treatment with SF results in time-dependent increases in the ultraviolet absorption of partially purified Helicobacter urease in the 280–340 nm region. This provides direct spectroscopic evidence for the formation of dithiocarbamates between the ITC group of SF and cysteine thiols of urease. The potencies of inactivation of Helicobacter urease by isothiocyanates structurally related to SF were surprisingly variable. Natural isothiocyanates closely related to SF, previously shown to be bactericidal (berteroin, hirsutin, phenethyl isothiocyanate, alyssin, and erucin), did not inactivate urease activity. Furthermore, SF is bactericidal against both urease positive and negative H. pylori strains. In contrast, some isothiocyanates such as benzoyl-ITC, are very potent urease inactivators, but are not bactericidal. The bactericidal effects of SF and other ITC against Helicobacter are therefore not obligatorily linked to urease inactivation, but may reduce the inflammatory component of Helicobacter infections. PMID:23583386

Luteinizing hormone-releasing hormone inactivation by purified pituitary plasma membranes: effects of receptor-binding studies.

Science.gov (United States)

Clayton, R N; Shakespear, R A; Duncan, J A; Marshall, J C

1979-05-01

Inactivation of LHRH by purified bovine pituitary plasma membranes was studied in vitro. After incubation of [125I]iodo-LHRH with plasma membranes, the amount of tracer bound to the pellet was measured, and the integrity of the unbound tracer in the supernatant was assessed. Reduction in ability to bind to anti-LHRH serum and to rebind to plasma membranes together with altered electrophoretic mobility on polyacrylamide gels showed that the unbound [125I]iodo-LHRH was inactivated. LHRH inactivation occurred rapidly and was dependent upon membrane concentration and incubation temperature. These results indicate that hormone inactivation must be taken into account in the interpretation of LHRH-receptor interactions. During 37 C incubations, the apparent absence of specific LHRH binding can be explained by inactivation of tracer hormone. Significant LHRH inactivation also occurred at 0 C, which in part explains the insensitivity of LHRH receptor assays. Assessment of LHRH inactivation by different particulate subcellular fractions of pituitary tissue showed that the inactivating enzyme was associated with the plasma membranes; other organelles did not alter LHRH. The enzyme appeared to be an integral part of the plasma membrane structure, since enzymic activity could not be removed by washing without reducing specific LHRH binding. Additionally, reduction of LHRH inactivation by the inhibitors Bacitracin and Trasylol and by magnesium was also accompanied by reduced LHRH binding. Previous studies have shown that the majority of LHRH binding to pituitary plasma membranes is to the low affinity site (approximately 10(-6) M), but the significance of this binding has been uncertain. Our findings indicate that low affinity binding probably represents binding of LHRH to the inactivating enzyme. The LHRH analog, D-Ser6(TBu), des Gly10, ethylamide, has greater biological activity than LHRH and is not inactivated to a significant extent by pituitary plasma membranes. The

Comparative study on the mechanisms of rotavirus inactivation by sodium dodecyl sulfate and ethylenediaminetetraacetate

Energy Technology Data Exchange (ETDEWEB)

Ward, R.L. (Sandia Labs., Albuquerque, NM); Ashley, C.S.

1980-06-01

This report describes a comparative study on the effects of the anionic detergent sodium dodecyl sulfate and the chelating agent ethylenediaminetetraacetate on purified rotavirus SA-11 particles. Both chemicals readily inactivated rotavirus at quite low concentrations and under very mild conditions. In addition, both agents modified the viral capsid and prevented the adsorption of inactivated virions to cells. Capsid damage by ethylenediaminetetraacetate caused a shift in the densities of rotavirions from about l.35 to about 1.37 g/ml and a reduction in their sedimentation coefficients. Sodium dodcyl sulfate, on the other hand, did not detectably alter either of these physical properties of rotavirions. Both agents caused some alteration of the isoelectric points of the virions. Finally, analysis of rotavirus proteins showed that ethylenediaminetetraacetate caused the loss of two protein peaks from the electrophoretic pattern of virions but sodium dodecyl sulfate caused the loss of only one of these same protein peaks.

A high-performance doped photocatalysts for inactivation of total coliforms in superficial waters using different sources of radiation.

Science.gov (United States)

Claro, Elis Marina Turini; Bidoia, Ederio Dino; de Moraes, Peterson Bueno

2016-07-15

Photocatalytic water treatment has a currently elevated electricity demand and maintenance costs, but the photocatalytic water treatment may also assist in overcoming the limitations and drawbacks of conventional water treatment processes. Among the Advanced Oxidation Processes, heterogeneous photocatalysis is one of the most widely and efficiently used processes to degrade and/or remove a wide range of polluting compounds. The goal of this work was to find out a highly efficient photocatalytic disinfection process in superficial water with different doped photocatalysts and using three sources of radiation: mercury vapor lamp, solar simulator and UV-A LED. Three doped photocatalysts were prepared, SiZnO, NSiZnO and FNSiZnO. The inactivation efficiency of each synthesized photocatalysts was compared to a TiO2 P25 (Degussa(®)) 0.5 g L(-1) control. Photolysis inactivation efficiency was 85% with UV-A LED, which is considered very high, demanding low electricity consumption in the process, whereas mercury vapor lamp and solar simulator yielded 19% and 13% inactivation efficiency, respectively. The best conditions were found with photocatalysts SiZnO, FNSiZnO and NSiZnO irradiated with UV-A LED, where efficiency exceeded 95% that matched inactivation of coliforms using the same irradiation and photocatalyst TiO2. All photocatalysts showed photocatalytic activity with all three radiation sources able to inactivate total coliforms from river water. The use of UV-A LED as the light source without photocatalyst is very promising, allowing the creation of cost-effective and highly efficient water treatment plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Heat inactivation of Salmonella spp. in fresh poultry compost by simulating early phase of composting process.

Science.gov (United States)

Singh, R; Kim, J; Jiang, X

2012-05-01

The purpose of this study was to determine the effect of moisture on thermal inactivation of Salmonella spp. in poultry litter under optimal composting conditions. Thermal inactivation of Salmonella was studied in fresh poultry compost by simulating early phase of composting process. A mixture of three Salmonella serotypes grown in Tryptic soy broth with rifampin (TSB-R) was inoculated in fresh compost with 40 or 50% moisture at a final concentration of c. 7 log CFU g(-1). The inoculated compost was kept in an environmental chamber which was programmed to rise from room temperature to target composting temperatures in 2 days. In poultry compost with optimal moisture content (50%), Salmonella spp. survived for 96, 72 and 24 h at 50, 55 and 60°C, respectively, as compared with 264, 144 and 72 h at 50, 55 and 60°C, respectively, in compost with suboptimal moisture (40%). Pathogen decline was faster during the come-up time owing to higher ammonia volatilization. Our results demonstrated that Salmonella spp. survived longer in fresh poultry compost with suboptimal moisture of 40% than in compost with optimal moisture of 50% during thermophilic composting. High nitrogen content of the poultry compost is an additional factor contributing to Salmonella inactivation through ammonia volatilization during thermal exposure. This research validated the effectiveness of the current composting guidelines on Salmonella inactivation in fresh poultry compost. Both initial moisture level and ammonia volatilization are important factors affecting microbiological safety and quality of compost product. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Inactivation of Smad4 in gastric carcinomas.

Science.gov (United States)

Powell, S M; Harper, J C; Hamilton, S R; Robinson, C R; Cummings, O W

1997-10-01

Allelic loss of chromosome 18q has been noted in intestinal type gastric adenocarcinomas. Smad4 is a gene located at 18q that was recently cloned in humans and found to be significantly altered in pancreatic cancers. We sought to determine whether Smad4 genetic alterations played a significant role in gastric tumorigenesis by studying 35 gastric adenocarcinomas of all histopathological types and pathological stages. Microdissected specimens were used for mutational analysis of Smad4 at the nucleotide level, including the entire coding region and intron/exon boundaries. Allelic imbalance was also analyzed at the Smad4 locus using two nearby microsatellite markers. One case of apparent biallelic inactivation of Smad4 was found in our study of 35 gastric carcinomas. A nonsense point mutation at codon 334 was demonstrated, which, similar to other Smad4 mutations, is predicted to truncate the conserved COOH-terminal domain of this protein. This Smad4 C to T transition mutation was proven to be somatically acquired. Allelic loss was also noted on chromosome 18q at a marker near Smad4 in this mutated gastric cancer, apparently producing complete inactivation of Smad4 in this tumor. Significant 18q allelic loss (56% of 34 informative cases) was noted in our gastric carcinomas using microsatellite markers near the Smad4 locus, regardless of histological subtype or pathological stage. Additionally, three cases of microsatellite instability were observed. Thus, Smad4 inactivation was noted in our gastric carcinomas; however, this event was rare. The frequent loss of chromosomal arm 18q observed in gastric cancers suggests the presence of other tumor suppressor genes in this region that are involved in gastric tumorigenesis. Further studies are needed to identify these other targets of inactivation during gastric cancer development.

Female meiotic sex chromosome inactivation in chicken.

Directory of Open Access Journals (Sweden)

Sam Schoenmakers

2009-05-01

Full Text Available During meiotic prophase in male mammals, the heterologous X and Y chromosomes remain largely unsynapsed, and meiotic sex chromosome inactivation (MSCI leads to formation of the transcriptionally silenced XY body. In birds, the heterogametic sex is female, carrying Z and W chromosomes (ZW, whereas males have the homogametic ZZ constitution. During chicken oogenesis, the heterologous ZW pair reaches a state of complete heterologous synapsis, and this might enable maintenance of transcription of Z- and W chromosomal genes during meiotic prophase. Herein, we show that the ZW pair is transiently silenced, from early pachytene to early diplotene using immunocytochemistry and gene expression analyses. We propose that ZW inactivation is most likely achieved via spreading of heterochromatin from the W on the Z chromosome. Also, persistent meiotic DNA double-strand breaks (DSBs may contribute to silencing of Z. Surprisingly, gammaH2AX, a marker of DSBs, and also the earliest histone modification that is associated with XY body formation in mammalian and marsupial spermatocytes, does not cover the ZW during the synapsed stage. However, when the ZW pair starts to desynapse, a second wave of gammaH2AX accumulates on the unsynapsed regions of Z, which also show a reappearance of the DSB repair protein RAD51. This indicates that repair of meiotic DSBs on the heterologous part of Z is postponed until late pachytene/diplotene, possibly to avoid recombination with regions on the heterologously synapsed W chromosome. Two days after entering diplotene, the Z looses gammaH2AX and shows reactivation. This is the first report of meiotic sex chromosome inactivation in a species with female heterogamety, providing evidence that this mechanism is not specific to spermatogenesis. It also indicates the presence of an evolutionary force that drives meiotic sex chromosome inactivation independent of the final achievement of synapsis.

Pathogen inactivation techniques.

Science.gov (United States)

Pelletier, J P R; Transue, S; Snyder, E L

2006-01-01

The desire to rid the blood supply of pathogens of all types has led to the development of many technologies aimed at the same goal--eradication of the pathogen(s) without harming the blood cells or generating toxic chemical agents. This is a very ambitious goal, and one that has yet to be achieved. One approach is to shun the 'one size fits all' concept and to target pathogen-reduction agents at the Individual component types. This permits the development of technologies that might be compatible with, for example, plasma products but that would be cytocidal and thus incompatible with platelet concentrates or red blood cell units. The technologies to be discussed include solvent detergent and methylene blue treatments--designed to inactivate plasma components and derivatives; psoralens (S-59--amotosalen) designed to pathogen-reduce units of platelets; and two products aimed at red blood cells, S-303 (a Frale--frangible anchor-linker effector compound) and Inactine (a binary ethyleneimine). A final pathogen-reduction material that might actually allow one material to inactivate all three blood components--riboflavin (vitamin B2)--is also under development. The sites of action of the amotosalen (S-59), the S-303 Frale, Inactine, and riboflavin are all localized in the nucleic acid part of the pathogen. Solvent detergent materials act by dissolving the plasma envelope, thus compromising the integrity of the pathogen membrane and rendering it non-infectious. By disrupting the pathogen's ability to replicate or survive, its infectivity is removed. The degree to which bacteria and viruses are affected by a particular pathogen-reducing technology relates to its Gram-positive or Gram-negative status, to the sporulation characteristics for bacteria, and the presence of lipid or protein envelopes for viruses. Concerns related to photoproducts and other breakdown products of these technologies remain, and the toxicology of pathogen-reduction treatments is a major ongoing area

Orbitofrontal participation in sign- and goal-tracking conditioned responses: Effects of nicotine.

Science.gov (United States)

Stringfield, Sierra J; Palmatier, Matthew I; Boettiger, Charlotte A; Robinson, Donita L

2017-04-01

Pavlovian conditioned stimuli can acquire incentive motivational properties, and this phenomenon can be measured in animals using Pavlovian conditioned approach behavior. Drugs of abuse can influence the expression of this behavior, and nicotine in particular exhibits incentive amplifying effects. Both conditioned approach behavior and drug abuse rely on overlapping corticolimbic circuitry. We hypothesize that the orbitofrontal cortex (OFC) regulates conditioned approach, and that one site of nicotine action is in the OFC where it reduces cortical output. To test this, we repeatedly exposed rats to 0.4 mg/kg nicotine (s.c.) during training and then pharmacologically inactivated the lateral OFC or performed in vivo electrophysiological recordings of lateral OFC neurons in the presence or absence of nicotine. In Experiment 1, animals were trained in a Pavlovian conditioning paradigm and behavior was evaluated after inactivation of the OFC by microinfusion of the GABA agonists baclofen and muscimol. In Experiment 2, we monitored phasic firing of OFC neurons during Pavlovian conditioning sessions. Nicotine reliably enhanced conditioned responding to the conditioned cue, and inactivation of the OFC reduced conditioned responding, especially the sign-tracking response. OFC neurons exhibited phasic excitations to cue presentation and during goal tracking, and nicotine acutely blunted this phasic neuronal firing. When nicotine was withheld, both conditioned responding and phasic firing in the OFC returned to the level of controls. These results suggest that the OFC is recruited for the expression of conditioned responses, and that nicotine acutely influences this behavior by reducing phasic firing in the OFC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inactivation of biological substances by local heating

Energy Technology Data Exchange (ETDEWEB)

Saito, Masahiro [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

1982-09-01

Mechanism of inactivation of biological substances caused by local heating was investigated. The effect of hot-zone formation by local heating on reaction of radicals was previously evaluated. The thermal increase in a hot zone due to low energy LET x-rays had little effect on reactibility of the radicals, but, in a hot zone caused by high energy LET x-rays, formed radicals seemed immediately react to active biological molecules to inactivate them. Direct thermal effect on biological molecules was analysed. Thermal increase in a hot zone may induce degenaration of biological molecules which seems to occur in a short time judged from the extension of a hot zone and the duration of high temperature.

Conformational lock and dissociative thermal inactivation of lentil seedling amine oxidase.

Science.gov (United States)

Moosavi-Nejad, S Zahra; Moosavi-Movahedi, Ali-Akbar; Rezaei-Tavirani, Mostafa; Floris, Giovanni; Medda, Rosaria

2003-03-31

The kinetics of thermal inactivation of copper-containing amine oxidase from lentil seedlings were studied in a 100 mM potassium phosphate buffer, pH 7, using putrescine as the substrate. The temperature range was between 47-60 degrees C. The thermal inactivation curves were not linear at 52 and 57 degrees C; three linear phases were shown. The first phase gave some information about the number of dimeric forms of the enzyme that were induced by the higher temperatures using the "conformational lock" pertaining theory to oligomeric enzyme. The "conformational lock" caused two additional dimeric forms of the enzyme when the temperature increased to 57 degrees C. The second and third phases were interpreted according to a dissociative thermal inactivation model. These phases showed that lentil amine oxidase was reversibly-dissociated before the irreversible thermal inactivation. Although lentil amine oxidase is not a thermostable enzyme, its dimeric structure can form "conformational lock," conferring a structural tolerance to the enzyme against heat stress.

Hydroxylamine technique for in vitro prevention of penicillin inactivation of tobramycin.

Science.gov (United States)

Falkowski, A J; Creger, R J

1984-01-01

Hydroxylamine was evaluated and found to be a highly effective agent for the in vitro prevention of penicillin inactivation of tobramycin. This inactivation reaction resulted in an underestimation of tobramycin concentrations and was dependent on time, temperature, amount and type of penicillin, and amount of tobramycin. Plasma samples containing tobramycin and three clinically relevant concentrations of ticarcillin, carbenicillin, azlocillin, or piperacillin were incubated with and without hydroxylamine, and tobramycin concentrations were monitored at 0, 12, 24, 48, and 72 h. The inactivation reaction was found to be completely inhibited by hydroxylamine (1 mg/ml) compared with a 27 to 50% loss of measured tobramycin concentration in the unprotected tobramycin-penicillin samples. Hydroxylamine did not interfere with the Emit enzyme immunoassay (Syva Co.) at either high or low tobramycin concentrations. Hydroxylamine was effective in inhibiting the tobramycin inactivation at both room and refrigerator temperatures and was 100% effective in protecting tobramycin on a 1:1 molar basis. PMID:6393865

Microbial electrolytic disinfection process for highly efficient Escherichia coli inactivation

DEFF Research Database (Denmark)

Zhou, Shaofeng; Huang, Shaobin; Li, Xiaohu

2018-01-01

extensively studied for recalcitrant organics removal, its application potential towards water disinfection (e.g., inactivation of pathogens) is still unknown. This study investigated the inactivation of Escherichia coli in a microbial electrolysis cell based bio-electro-Fenton system (renamed as microbial......Water quality deterioration caused by a wide variety of recalcitrant organics and pathogenic microorganisms has become a serious concern worldwide. Bio-electro-Fenton systems have been considered as cost-effective and highly efficient water treatment platform technology. While it has been......]OH was identified as one potential mechanism for disinfection. This study successfully demonstrated the feasibility of bio-electro-Fenton process for pathogens inactivation, which offers insight for the future development of sustainable, efficient, and cost-effective biological water treatment technology....

Effects of PEF and heat pasteurization on PME activity in orange juice with regard to a new inactivation kinetic model.

Science.gov (United States)

Agcam, E; Akyıldız, A; Evrendilek, G Akdemir

2014-12-15

The inactivation kinetics of pectin methyl esterase (PME) during the shelf life (4°C-180 days) of freshly squeezed orange juice samples processed by both pulsed electric fields (PEF) and heat pasteurization (HP) was evaluated in the study. The PME inactivation level after the PEF (25.26 kV/cm-1206.2 μs) and HP (90°C-20s) treatments were 93.8% and 95.2%, respectively. The PME activity of PEF-processed samples decreased or did not change, while that of HP samples increased during storage (p<0.01). A kinetic model was developed expressing PME inactivation as a function of the PEF treatment conditions, and this enabled the estimation of the reaction rate constant (587.8-2375.4s(-1)), and the time required for a 90% reduction (De, 3917.7-969.5s). Quantification of the increase in PEF energy to ensure a ten-fold reduction in De (ze, 63.7 J), activation electric fields (-921.2 kV cm(-1)mol(-1)), and electrical activation energy (12.9 kJ mol(-1)) was also carried out. Consequently, PEF processing was very effective for the inactivation of PME and for providing stability of orange juice during storage. Copyright © 2014. Published by Elsevier Ltd.

Transcriptional Profiling of Cholinergic Neurons From Basal Forebrain Identifies Changes in Expression of Genes Between Sleep and Wake.

Science.gov (United States)

Nikonova, Elena V; Gilliland, Jason DA; Tanis, Keith Q; Podtelezhnikov, Alexei A; Rigby, Alison M; Galante, Raymond J; Finney, Eva M; Stone, David J; Renger, John J; Pack, Allan I; Winrow, Christopher J

2017-06-01

To assess differences in gene expression in cholinergic basal forebrain cells between sleeping and sleep-deprived mice sacrificed at the same time of day. Tg(ChAT-eGFP)86Gsat mice expressing enhanced green fluorescent protein (eGFP) under control of the choline acetyltransferase (Chat) promoter were utilized to guide laser capture of cholinergic cells in basal forebrain. Messenger RNA expression levels in these cells were profiled using microarrays. Gene expression in eGFP(+) neurons was compared (1) to that in eGFP(-) neurons and to adjacent white matter, (2) between 7:00 am (lights on) and 7:00 pm (lights off), (3) between sleep-deprived and sleeping animals at 0, 3, 6, and 9 hours from lights on. There was a marked enrichment of ChAT and other markers of cholinergic neurons in eGFP(+) cells. Comparison of gene expression in these eGFP(+) neurons between 7:00 am and 7:00 pm revealed expected differences in the expression of clock genes (Arntl2, Per1, Per2, Dbp, Nr1d1) as well as mGluR3. Comparison of expression between spontaneous sleep and sleep-deprived groups sacrificed at the same time of day revealed a number of transcripts (n = 55) that had higher expression in sleep deprivation compared to sleep. Genes upregulated in sleep deprivation predominantly were from the protein folding pathway (25 transcripts, including chaperones). Among 42 transcripts upregulated in sleep was the cold-inducible RNA-binding protein. Cholinergic cell signatures were characterized. Whether the identified genes are changing as a consequence of differences in behavioral state or as part of the molecular regulatory mechanism remains to be determined. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Buffer AVL Alone Does Not Inactivate Ebola Virus in a Representative Clinical Sample Type.

Science.gov (United States)

Smither, Sophie J; Weller, Simon A; Phelps, Amanda; Eastaugh, Lin; Ngugi, Sarah; O'Brien, Lyn M; Steward, Jackie; Lonsdale, Steve G; Lever, Mark S

2015-10-01

Rapid inactivation of Ebola virus (EBOV) is crucial for high-throughput testing of clinical samples in low-resource, outbreak scenarios. The EBOV inactivation efficacy of Buffer AVL (Qiagen) was tested against marmoset serum (EBOV concentration of 1 × 10(8) 50% tissue culture infective dose per milliliter [TCID50 · ml(-1)]) and murine blood (EBOV concentration of 1 × 10(7) TCID50 · ml(-1)) at 4:1 vol/vol buffer/sample ratios. Posttreatment cell culture and enzyme-linked immunosorbent assay (ELISA) analysis indicated that treatment with Buffer AVL did not inactivate EBOV in 67% of samples, indicating that Buffer AVL, which is designed for RNA extraction and not virus inactivation, cannot be guaranteed to inactivate EBOV in diagnostic samples. Murine blood samples treated with ethanol (4:1 [vol/vol] ethanol/sample) or heat (60°C for 15 min) also showed no viral inactivation in 67% or 100% of samples, respectively. However, combined Buffer AVL and ethanol or Buffer AVL and heat treatments showed total viral inactivation in 100% of samples tested. The Buffer AVL plus ethanol and Buffer AVL plus heat treatments were also shown not to affect the extraction of PCR quality RNA from EBOV-spiked murine blood samples. © Crown copyright 2015.

Estrogen-mediated inactivation of FOXO3a by the G protein-coupled estrogen receptor GPER

International Nuclear Information System (INIS)

Zekas, Erin; Prossnitz, Eric R.

2015-01-01

Estrogen (17β-estradiol) promotes the survival and proliferation of breast cancer cells and its receptors represent important therapeutic targets. The cellular actions of estrogen are mediated by the nuclear estrogen receptors ERα and ERβ as well as the 7-transmembrane spanning G protein-coupled estrogen receptor (GPER). We previously reported that estrogen activates the phosphoinositide 3-kinase (PI3Kinase) pathway via GPER, resulting in phosphatidylinositol (3,4,5)-trisphosphate (PIP3) production within the nucleus of breast cancer cells; however, the mechanisms and consequences of this activity remained unclear. MCF7 breast cancer cells were transfected with GFP-fused Forkhead box O3 (FOXO3) as a reporter to assess localization in response to estrogen stimulation. Inhibitors of PI3Kinases and EGFR were employed to determine the mechanisms of estrogen-mediated FOXO3a inactivation. Receptor knockdown with siRNA and the selective GPER agonist G-1 elucidated the estrogen receptor(s) responsible for estrogen-mediated FOXO3a inactivation. The effects of selective estrogen receptor modulators and downregulators (SERMs and SERDs) on FOXO3a in MCF7 cells were also determined. Cell survival (inhibition of apoptosis) was assessed by caspase activation. In the estrogen-responsive breast cancer cell line MCF7, FOXO3a inactivation occurs on a rapid time scale as a result of GPER, but not ERα, stimulation by estrogen, established by the GPER-selective agonist G-1 and knockdown of GPER and ERα. GPER-mediated inactivation of FOXO3a is effected by the p110α catalytic subunit of PI3Kinase as a result of transactivation of the EGFR. The SERMs tamoxifen and raloxifene, as well as the SERD ICI182,780, were active in mediating FOXO3a inactivation in a GPER-dependent manner. Additionally, estrogen-and G-1-mediated stimulation of MCF7 cells results in a decrease in caspase activation under proapoptotic conditions. Our results suggest that non-genomic signaling by GPER contributes

Salvinorin A preserves cerebral pial artery autoregulation after forebrain ischemia via the PI3K/AKT/cGMP pathway

Directory of Open Access Journals (Sweden)

H.P. Dong

2018-03-01

Full Text Available This study aimed to investigate the protective effect of salvinorin A on the cerebral pial artery after forebrain ischemia and explore related mechanisms. Thirty Sprague-Dawley rats received forebrain ischemia for 10 min. The dilation responses of the cerebral pial artery to hypercapnia and hypotension were assessed in rats before and 1 h after ischemia. The ischemia reperfusion (IR control group received DMSO (1 µL/kg immediately after ischemia. Two different doses of salvinorin A (10 and 20 µg/kg were administered following the onset of reperfusion. The 5th, 6th, and 7th groups received salvinorin A (20 µg/kg and LY294002 (10 µM, L-NAME (10 μM, or norbinaltorphimine (norBIN, 1 μM after ischemia. The levels of cGMP in the cerebrospinal fluid (CSF were also measured. The phosphorylation of AKT (p-AKT was measured in the cerebral cortex by western blot at 24 h post-ischemia. Cell necrosis and apoptosis were examined by hematoxylin-eosin staining (HE and TUNEL staining, respectively. The motor function of the rats was evaluated at 1, 2, and 5 days post-ischemia. The dilation responses of the cerebral pial artery were significantly impaired after ischemia and were preserved by salvinorin A treatment. In addition, salvinorin A significantly increased the levels of cGMP and p-AKT, suppressed cell necrosis and apoptosis of the cerebral cortex and improved the motor function of the rats. These effects were abolished by LY294002, L-NAME, and norBIN. Salvinorin A preserved cerebral pial artery autoregulation in response to hypercapnia and hypotension via the PI3K/AKT/cGMP pathway.

Reaction of uridine diphosphate galactose 4-epimerase with a suicide inactivator

International Nuclear Information System (INIS)

Flentke, G.R.; Frey, P.A.

1990-01-01

UDPgalactose 4-epimerase from Escherichia coli is rapidly inactivated by the compounds uridine 5'-diphosphate chloroacetol (UDC) and uridine 5'-diphosphate bromoacetol (UCB). Both UDC and UDB inactivate the enzyme in neutral solution concomitant with the appearance of chromophores absorbing maximally at 325 and 328 nm, respectively. The reaction of UDC with the enzyme follows saturation kinetics characterized by a K D of 0.110 mM and k inact of 0.84 min -1 at pH 8.5 and ionic strength 0.2 M. The inactivation by UDC is competitively inhibited by competitive inhibitors of UDPgalactose 4-epimerase, and it is accompanied by the tight but noncovalent binding of UDC to the enzyme in a stoichiometry of 1 mol of UDC/mol of enzyme dimer, corresponding to 1 mol of UDC/mol of enzyme-bound NAD + . The inactivation of epimerase by uridine 5'-diphosphate [ 2 H 2 ]chloroacetol proceeds with a primary kinetic isotope effect (k H /k D ) of 1.4. The inactivation mechanism is proposed to involve a minimum of three steps: (a) reversible binding of UDC to the active site of UDPgalactose 4-epimerase; (b) enolization of the chloroacetol moiety of enzyme-bound UDC, catalyzed by an enzymic general base at the active site; (c) alkylation of the nicotinamide ring of NAD + at the active site by the chloroacetol enolate. The resulting adduct between UDC and NAD + is proposed to be the chromophore with λ max at 325 nm. The enzymic general base required to facilitate proton transfer in redox catalysis by this enzyme may be the general base that facilitates enolization of the chloroacetol moiety of UDC in the inactivation reaction

The selective alpha7 nicotinic acetylcholine receptor agonist A-582941 activates immediate early genes in limbic regions of the forebrain

DEFF Research Database (Denmark)

Thomsen, M S; Mikkelsen, J D; Timmermann, D B

2008-01-01

to study whether alpha7 nAChR stimulation activates brain regions involved in cognition in juvenile as well as adult individuals. Here, we compared the effects of the novel and selective alpha7 nAChR agonist 2-methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole (A-582941) in the juvenile...... regions critically involved in working memory and attention. Furthermore, this effect is more pronounced in juvenile than adult rats, indicating that the juvenile forebrain is more responsive to alpha7 nAChR stimulation. This observation may be relevant in the treatment of juvenile-onset schizophrenia....

Post-irradiation inactivation, protection, and repair of the sulfhydryl enzyme malate synthase

International Nuclear Information System (INIS)

Durchschlag, H.; Zipper, P.

1985-01-01

Malate synthase from baker's yeast, a trimeric sulfhydryl enzyme with one essential sulfhydryl group per subunit, was inactivated by 2 kGy X-irradiation in air-saturated aqueous solution (enzyme concentration: 0.5 mg/ml). The radiation induced changes of enzymic activity were registered at about 0,30,60 h after irradiation. To elucidate the role of OH - , O 2 , and H 2 O 2 in the X-ray inactivation of the enzyme, experiments were performed in the absence of presence of different concentrations of specific additives (formate, superoxide dismutase, catalase). These additives were added to malate synthase solutions before or after X-irradiation. Moreover, repairs of inactivated malate synthase were initiated at about 0 or 30 h after irradiation by means of the sulfhydryl agent dithiothreitol. Experiments yielded the following results: 1. Irradiation of malate synthase in the absence of additives inactivated the enzyme immediately to a residual activity Asub(r)=3% (corresponding to a D 37 =0.6 kGy), and led to further slow inactivation in the post-irradiation phase. Repairs, initiated at different times after irradiation, restored enzymic activity considerably. The repair initiated at t=0 led to Asub(r)=21%; repairs started later on resulted in somewhat lower activities. The decay of reparability, however, was found to progress more slowly than post-irradiation inactivation itself. After completion of repair the activities of repaired samples did not decrease significantly. 2. The presence of specific additives during irradiation caused significant protective effects against primary inactivation. The protection by formate was very pronounced (e.g., Asub(r)=72% and D 37 =6 kGy for 100 mM formate). The presence of catalytic amounts of superoxide dismutase and/or catalase exhibited only minor effects, depending on the presence and concentration of formate. (orig.)

An inactivated yellow fever 17DD vaccine cultivated in Vero cell cultures.

Science.gov (United States)

Pereira, Renata C; Silva, Andrea N M R; Souza, Marta Cristina O; Silva, Marlon V; Neves, Patrícia P C C; Silva, Andrea A M V; Matos, Denise D C S; Herrera, Miguel A O; Yamamura, Anna M Y; Freire, Marcos S; Gaspar, Luciane P; Caride, Elena

2015-08-20

Yellow fever is an acute infectious disease caused by prototype virus of the genus Flavivirus. It is endemic in Africa and South America where it represents a serious public health problem causing epidemics of hemorrhagic fever with mortality rates ranging from 20% to 50%. There is no available antiviral therapy and vaccination is the primary method of disease control. Although the attenuated vaccines for yellow fever show safety and efficacy it became necessary to develop a new yellow fever vaccine due to the occurrence of rare serious adverse events, which include visceral and neurotropic diseases. The new inactivated vaccine should be safer and effective as the existing attenuated one. In the present study, the immunogenicity of an inactivated 17DD vaccine in C57BL/6 mice was evaluated. The yellow fever virus was produced by cultivation of Vero cells in bioreactors, inactivated with β-propiolactone, and adsorbed to aluminum hydroxide (alum). Mice were inoculated with inactivated 17DD vaccine containing alum adjuvant and followed by intracerebral challenge with 17DD virus. The results showed that animals receiving 3 doses of the inactivated vaccine (2 μg/dose) with alum adjuvant had neutralizing antibody titers above the cut-off of PRNT50 (Plaque Reduction Neutralization Test). In addition, animals immunized with inactivated vaccine showed survival rate of 100% after the challenge as well as animals immunized with commercial attenuated 17DD vaccine. Copyright © 2015 Elsevier Ltd. All rights reserved.

Regulation of Na+ channel inactivation by the DIII and DIV voltage-sensing domains.

Science.gov (United States)

Hsu, Eric J; Zhu, Wandi; Schubert, Angela R; Voelker, Taylor; Varga, Zoltan; Silva, Jonathan R

2017-03-06

Functional eukaryotic voltage-gated Na + (Na V ) channels comprise four domains (DI-DIV), each containing six membrane-spanning segments (S1-S6). Voltage sensing is accomplished by the first four membrane-spanning segments (S1-S4), which together form a voltage-sensing domain (VSD). A critical Na V channel gating process, inactivation, has previously been linked to activation of the VSDs in DIII and DIV. Here, we probe this interaction by using voltage-clamp fluorometry to observe VSD kinetics in the presence of mutations at locations that have been shown to impair Na V channel inactivation. These locations include the DIII-DIV linker, the DIII S4-S5 linker, and the DIV S4-S5 linker. Our results show that, within the 10-ms timeframe of fast inactivation, the DIV-VSD is the primary regulator of inactivation. However, after longer 100-ms pulses, the DIII-DIV linker slows DIII-VSD deactivation, and the rate of DIII deactivation correlates strongly with the rate of recovery from inactivation. Our results imply that, over the course of an action potential, DIV-VSDs regulate the onset of fast inactivation while DIII-VSDs determine its recovery. © 2017 Hsu et al.

Influenza virus inactivated by artificial ribonucleases as a prospective killed virus vaccine.

Science.gov (United States)

Fedorova, Antonina A; Goncharova, Elena P; Kovpak, Mikhail P; Vlassov, Valentin V; Zenkova, Marina A

2012-04-19

The inactivation of viral particles with agents causing minimal damage to the structure of surface epitopes is a well-established approach for the production of killed virus vaccines. Here, we describe new agents for the inactivation of influenza virus, artificial ribonucleases (aRNases), which are chemical compounds capable of cleaving RNA molecules. Several aRNases were identified, exhibiting significant virucidal activity against the influenza A virus and causing a minimal effect on the affinity of monoclonal antibodies for the inactivated virus. Using a murine model of the influenza virus infection, a high protective activity of the aRNase-inactivated virus as a vaccine was demonstrated. The results of the experiments demonstrate the efficacy of novel chemical agents in the preparation of vaccines against influenza and, perhaps, against other infections caused by RNA viruses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of pH, Salt and Temperature on Pressure Inactivation of Hepatitis A virus

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The effects of pH (3-7), NaCl (0-6%), and temperature on pressure inactivation of hepatitis A virus (HAV) were determined. The HAV samples were treated at 400 MPa for 1 min at 5, 20, and 50C. Decreasing solution pH enhanced pressure inactivation of HAV. This enhanced inactivation effect was most e...

Inactivation of human enteric virus surrogates by high-intensity ultrasound.

Science.gov (United States)

Su, Xiaowei; Zivanovic, Svetlana; D'Souza, Doris H

2010-09-01

Foodborne viruses, especially human noroviruses, are recognized as leading causes of nonbacterial gastroenteritis worldwide. Development of effective inactivation methods is of great importance to control their spread. In this study, the effect of high-intensity ultrasound (HIUS) on the infectivity of three foodborne virus surrogates was investigated. The three surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), and MS2 bacteriophage, were diluted in phosphate-buffered saline (PBS) or orange juice to a titer of approximately 6 log(10) PFU/mL or approximately 4 log(10) PFU/mL. The ultrasound treatment was performed in duplicate by immersing the HIUS probe in virus-containing solution that was cooled in ice-water and sonicated at 20 kHz for 2, 5, 10, 15, 20, and 30 min with 30 sec on and 30 sec off. The infectivity of the recovered viruses after each ultrasound treatment was evaluated in duplicate using standardized plaque assays and compared to untreated controls. The results show that HIUS effectiveness depended on the virus type, the initial titer of the viruses, and the virus suspension solution. At titers of approximately 4 log(10) PFU/mL in PBS, feline calicivirus (FCV)-F9, MS2, and murine norovirus (MNV)-1 required 5-, 10-, and 30-min treatment, respectively, for complete inactivation. At initial titers of approximately 4 log(10) PFU/mL in orange juice, FCV-F9 required a 15-min treatment for complete inactivation and only a 1.55 log(10) PFU/mL reduction was achieved for MNV-1 in orange juice after 30-min treatment. Thus, inactivation by HIUS in orange juice was much lower than in PBS. Experiments using titers of approximately 6 log(10) PFU/mL showed decreased effects compared to those using titers of approximately 4 log(10) PFU/mL. These results indicate that HIUS alone is not sufficient to inactivate virus in food. Hurdle technologies that combine HIUS with antimicrobials, heat, or pressure should be explored for viral inactivation.

X-linked gene expression and X-chromosome inactivation: marsupials, mouse, and man compared.

Science.gov (United States)

VandeBerg, J L; Robinson, E S; Samollow, P B; Johnston, P G

1987-01-01

The existence of paternal X inactivation in Australian and American marsupial species suggests that this feature of X-chromosome dosage compensation is not a recent adaptation, but probably predates the evolutionary separation of the Australian and American marsupial lineages. Although it is theoretically possible that the marsupial system is one of random X inactivation with p greater than 0.99 and q less than 0.01 and dependent on parental source, no instance of random X inactivation (p = q or p not equal to q) has ever been verified in any tissue or cell type of any marsupial species. Therefore, we conclude that the most fundamental difference in X inactivation of marsupials and eutherians is whether the inactive X is the paternal one or is determined at random (with p = q in most but not all cases). The only other unequivocal difference between eutherians and marsupials is that both X chromosomes are active in mice and human oocytes, but not in kangaroo oocytes. Apparently, the inactive X is reactivated at a later meiotic stage or during early embryogenesis in kangaroos. X-chromosome inactivation takes place early in embryogenesis of eutherians and marsupials. Extraembryonic membranes of mice exhibit paternal X inactivation, whereas those of humans seem to exhibit random X inactivation with p greater than q (i.e., preferential paternal X inactivation). In general, extraembryonic membranes of marsupial exhibit paternal X inactivation, but the Gpd locus is active on both X chromosomes in at least some cells of kangaroo yolk sac. It is difficult to draw any general conclusion because of major differences in embryogeny of mice, humans, and marsupials, and uncertainties in interpreting the data from humans. Other differences between marsupials and eutherians in patterns of X-linked gene expression and X-chromosome inactivation seem to be quantitative rather than qualitative. Partial expression of some genes on the inactive X is characteristic of marsupials, with

Effect of rising time of rectangular pulse on inactivation of staphylococcus aureus by pulsed electric field

Science.gov (United States)

Zhang, Ruobing; Liang, Dapeng; Zheng, Nanchen; Xiao, Jianfu; Mo, Mengbin; Li, Jing

2013-03-01

Pulsed electric field (PEF) is a novel non-thermal food processing technology that involves the electric discharge of high voltage short pulses through the food product. In PEF study, rectangular pulses are most commonly used for inactivating microorganisms. However, little information is available on the inactivation effect of rising time of rectangular pulse. In this paper, inactivation effects, electric field strength, treatment time and conductivity on staphylococcus aureus inactivation were investigated when the pulse rising time is reduced from 2.5 μs to 200 ns. Experimental results showed that inactivation effect of PEF increased with electric field strength, solution conductivity and treatment time. Rising time of the rectangular pulse had a significant effect on the inactivation of staphylococcus aureus. Rectangular pulses with a rising time of 200 ns had a better inactivation effect than that with 2 μs. In addition, temperature increase of the solution treated by pulses with 200 ns rising time was lower than that with 2 μs. In order to obtain a given inactivation effect, treatment time required for the rectangular pulse with 200 ns rise time was shorter than that with 2 μs.

Effect of rising time of rectangular pulse on inactivation of staphylococcus aureus by pulsed electric field

International Nuclear Information System (INIS)

Zhang, Ruobing; Liang, Dapeng; Xiao, Jianfu; Mo, Mengbin; Li, Jing; Zheng, Nanchen

2013-01-01

Pulsed electric field (PEF) is a novel non-thermal food processing technology that involves the electric discharge of high voltage short pulses through the food product. In PEF study, rectangular pulses are most commonly used for inactivating microorganisms. However, little information is available on the inactivation effect of rising time of rectangular pulse. In this paper, inactivation effects, electric field strength, treatment time and conductivity on staphylococcus aureus inactivation were investigated when the pulse rising time is reduced from 2.5 μs to 200 ns. Experimental results showed that inactivation effect of PEF increased with electric field strength, solution conductivity and treatment time. Rising time of the rectangular pulse had a significant effect on the inactivation of staphylococcus aureus. Rectangular pulses with a rising time of 200 ns had a better inactivation effect than that with 2 μs. In addition, temperature increase of the solution treated by pulses with 200 ns rising time was lower than that with 2 μs. In order to obtain a given inactivation effect, treatment time required for the rectangular pulse with 200 ns rise time was shorter than that with 2 μs.

ASSESSING THE EFFECTIVENESS OF LOW PRESSURE ULTRAVIOLET LIGHT FOR INACTIVATING HELICOBACTER PYLORI

Science.gov (United States)

Three strains of Helicobacter pylori were exposed to ultraviolet (UV) light from a low-pressure source to determine log inactivation versus applied fluence. Results indicate that H. pylori is readily inactivated at UV fluences typically used in water treatment r...

Some factors affecting urokinase inactivation. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Iwata, Hiroo; Iketa, Yoshito

1985-10-01

The enzymatic activity of urokinase adsorbed on various polymer surfaces was measured to study the interaction between protein and polymers. The polymer films on which urokinase was adsorbed were exposed to either a high temperature or ..gamma..-radiation. The thermal inactivation rates were higher on hydrophobic polymers such as poly(ethylene terephthalate), nylon 6, and poly(vinylidene fluoride) than hydrophilic polymers like cellulose and ethylene-vinyl alcohol copolymer, indicating their substantial dependence on the interfacial free energy between the polymer and water. A similar dependence was also seen for the ..gamma..-radiation inactivation. Urokinase adsorbed on the hydrophobic polymers lost more easily its enzymatic activity by exposure to ..gamma..-radiation. The interfacial free energy seems to be one of the driving forces to denaturate proteins on polymers.

Inactivation of Staphylococcus aureus and Enterococcus faecalis by a direct-current, cold atmospheric-pressure air plasma microjet.

Science.gov (United States)

Tian, Ye; Sun, Peng; Wu, Haiyan; Bai, Na; Wang, Ruixue; Zhu, Weidong; Zhang, Jue; Liu, Fuxiang

2010-07-01

A direct-current, cold atmospheric-pressure air plasma microjet (PMJ) was performed to inactivate Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis) in air. The process of sterilization and morphology of bacteria was observed. We wish to know the possible inactivation mechanisms of PMJ and explore a potential application in dental and other temperature sensitive treatment. In this study, we employed a direct current, atmospheric pressure, cold air PMJ to inactivate bacterias. Scanning electron microscopy was employed to evaluate the morphology of S. aureus and showed rupture of cell walls after the plasma treatment and Optical emission spectrum (OES) were used to understand the possible inactivation mechanisms of PMJ. The inactivation rates could reach 100% in 5 min. When the distance between the exit nozzle of the PMJ device and Petri dish was extended from 1 cm to 3 cm, effective inactivation was also observed with a similar inactivation curve. The inactivation of bacteria is attributed to the abundant reactive oxygen and nitrogen species, as well as ultroviolet radiation in the plasma. Different life spans and defensibilities of these killing agents may hold the key to understanding the different inactivation curves at different treatment distances.

Transient inactivation of the ventral hippocampus in neonatal rats impairs the mesolimbic regulation of prefrontal glutamate release in adulthood

DEFF Research Database (Denmark)

Bortz, D M; Jørgensen, Christinna Vangsgaard; Mikkelsen, J D

2014-01-01

Cognitive deficits in schizophrenia (SZ) reflect maturational disruptions within a neural system that includes the ventral hippocampus (VH), nucleus accumbens (NAc), basal forebrain, and prefrontal cortex (PFC). A better understanding of these changes may reveal drug targets for more efficacious ...

Using ultrasound technology for the inactivation and thermal sensitization of peroxidase in green coconut water.

Science.gov (United States)

Rojas, Meliza Lindsay; Trevilin, Júlia Hellmeister; Funcia, Eduardo Dos Santos; Gut, Jorge Andrey Wilhelms; Augusto, Pedro Esteves Duarte

2017-05-01

Green coconut water has unique nutritional and sensorial qualities. Despite the different technologies already studied, its enzymatic stability is still challenging. This study evaluated the use of ultrasound technology (US) for inactivating/sensitizing coconut water peroxidase (POD). The effect of both US application alone and as a pre-treatment to thermal processing was evaluated. The enzyme activity during US processing was reduced 27% after 30min (286W/L, 20kHz), demonstrating its high resistance. The thermal inactivation was described by the Weibull model under non-isothermal conditions. The enzyme became sensitized to heat after US pre-treatment. Further, the use of US resulted in more uniform heat resistance. The results suggest that US is a good technology for sensitizing enzymes before thermal processing (even for an enzyme with high thermal resistance). Therefore, the use of this technology could decrease the undesirable effects of long times and/or the high temperatures of the conventional thermal processing. Copyright © 2016 Elsevier B.V. All rights reserved.

Inactivation of Ichthyophonus spores using sodium hypochlorite and polyvinyl pyrrolidone iodine.

Science.gov (United States)

Hershberger, P K; Pacheco, C A; Gregg, J L

2008-11-01

Chlorine and iodine solutions were effective at inactivating Ichthyophonus spores in vitro. Inactivation in sea water increased directly with halogen concentration and exposure duration, with significant differences (P < 0.05) from controls occurring at all chlorine concentrations and exposure durations tested (1.5-13.3 ppm for 1-60 min) and at most iodine concentrations and exposure durations tested (1.2 ppm for 60 min and 5.9-10.7 ppm for 1-60 min). However, 10-fold reductions in spore viability occurred only after exposure to halogen solutions at higher concentrations and/or longer durations (13 ppm total chlorine for 1-60 min, 5.9 ppm total iodine for 60 min, and 10.7 ppm total iodine for 1-60 min). Inactivation efficacy was greater when halogen solutions were prepared in fresh water, presumably because of combined effects of halogen-induced inactivation and general spore instability in fresh water. The results have practical implications for disinfection and biocontainment in research laboratories and other facilities that handle live Ichthyophonus cultures and/or infected fish.

Mapping the co-localization of the circadian proteins PER2 and BMAL1 with enkephalin and substance P throughout the rodent forebrain.

Directory of Open Access Journals (Sweden)

Ariana Frederick

Full Text Available Despite rhythmic expression of clock genes being found throughout the central nervous system, very little is known about their function outside of the suprachiasmatic nucleus. Determining the pattern of clock gene expression across neuronal subpopulations is a key step in understanding their regulation and how they may influence the functions of various brain structures. Using immunofluorescence and confocal microscopy, we quantified the co-expression of the clock proteins BMAL1 and PER2 with two neuropeptides, Substance P (SubP and Enkephalin (Enk, expressed in distinct neuronal populations throughout the forebrain. Regions examined included the limbic forebrain (dorsal striatum, nucleus accumbens, amygdala, stria terminalis, thalamus medial habenula of the thalamus, paraventricular nucleus and arcuate nucleus of the hypothalamus and the olfactory bulb. In most regions examined, BMAL1 was homogeneously expressed in nearly all neurons (~90%, and PER2 was expressed in a slightly lower proportion of cells. There was no specific correlation to SubP- or Enk- expressing subpopulations. The olfactory bulb was unique in that PER2 and BMAL1 were expressed in a much smaller percentage of cells, and Enk was rarely found in the same cells that expressed the clock proteins (SubP was undetectable. These results indicate that clock genes are not unique to specific cell types, and further studies will be required to determine the factors that contribute to the regulation of clock gene expression throughout the brain.

Thermal and Carbon Dioxide Inactivation of Alkaline Phosphatase in Buffer and Milk

Directory of Open Access Journals (Sweden)

Osman Erkmen

2004-01-01

Full Text Available The effects of temperature and CO2 treatment on the inactivation of alkaline phosphatase (ALP were studied. The thermal stability of ALP was found to be significantly (P< 0.05 different in glycine/NaOH buffer, pasteurized milk and raw milk. ALP was completely inactivated in the buffer at 60, 70 and 80 °C but approximately 12 % of activity was present at 50 °C after 55 min of treatment. The time required for complete inactivation of the enzyme in the buffer was reduced from 50 to 4 min as temperature increased from 60 to 80 °C. Complete inactivation of the enzyme in pasteurized milk was achieved at 70 and 80 °C but 28 and 15 % of ALP activity was still present at 50 and 60 °C after 120 min of treatment. Inactivation time for raw milk was reduced nearly 18-fold by increasing temperature from 50 to 70 °C. ALP in the buffer exposed to CO2 (under atmospheric pressure treatment at different temperatures showed a decrease in enzyme activity. Inactivation was found to be higher as the temperature increased from 20 to 50 °C. At the end of a 30-min treatment, residual ALP activity was found to be 84 and 19 % at 20 and 50 °C, respectively. Faster drop in pH and enzyme activity occurred within 5 min. The change in pH and enzyme activity dependant on CO2 treatment was not observed in raw milk mainly due to strong buffering capacity of milk.

Nucleus incertus inactivation impairs spatial learning and memory in rats.

Science.gov (United States)

Nategh, Mohsen; Nikseresht, Sara; Khodagholi, Fariba; Motamedi, Fereshteh

2015-02-01

Nucleus incertus (NI) is a pontine nucleus which releases mainly GABA and relaxin-3 in rats. Its suggested functions include response to stress, arousal, and modulation of hippocampal theta rhythm. Since the role of NI in learning and memory has not been well characterized, therefore the involvement of this nucleus in spatial learning and memory and the aftermath hippocampal levels of c-fos and pCREB were evaluated. NI was targeted by implanting cannula in male rats. For reference memory, NI was inactivated by lidocaine (0.4 μl, 4%) at three stages of acquisition, consolidation and retrieval in Morris water maze paradigm. For working memory, NI was inactivated in acquisition and retrieval phases. Injection of lidocaine prior to the first training session of reference memory significantly increased the distance moved, suggesting that inactivation of NI delays acquisition in this spatial task. Inactivation also interfered with the retrieval phase of spatial reference memory, as the time in target quadrant for lidocaine group was less, and the escape latency was higher compared to the control group. However, no difference was observed in the consolidation phase. In the working memory task, with inter-trial intervals of 75 min, the escape latency was higher when NI was inactivated in the retrieval phase. In addition, c-fos and pCREB/CREB levels decreased in NI-inhibited rats. This study suggests that nucleus incertus might participate in acquisition of spatial reference, and retrieval of both spatial reference and working memory. Further studies should investigate possible roles of NI in the hippocampal plasticity. Copyright © 2014 Elsevier Inc. All rights reserved.

Pathogen inactivation of Dengue virus in red blood cells using amustaline and glutathione.

Science.gov (United States)

Aubry, Maite; Laughhunn, Andrew; Santa Maria, Felicia; Lanteri, Marion C; Stassinopoulos, Adonis; Musso, Didier

2017-12-01

Dengue virus (DENV) is an arbovirus primarily transmitted through mosquito bite; however, DENV transfusion-transmitted infections (TTIs) have been reported and asymptomatic DENV RNA-positive blood donors have been identified in endemic countries. DENV is considered a high-risk pathogen for blood safety. One of the mitigation strategies to prevent arbovirus TTIs is pathogen inactivation. In this study we demonstrate that the amustaline and glutathione (S-303/GSH) treatment previously found effective against Zika virus in red blood cells (RBCs) is also effective in inactivating DENV. Red blood cells were spiked with high levels of DENV. Viral RNA loads and infectious titers were measured in the untreated control and before and after pathogen inactivation treatment of RBC samples. DENV infectivity was also assessed over five successive cell culture passages to detect any potential residual replicative virus. The mean ± SD DENV titer in RBCs before inactivation was 6.61 ± 0.19 log 50% tissue culture infectious dose (TCID 50 )/mL and the mean viral RNA load was 8.42 log genome equivalents/mL. No replicative DENV was detected either immediately after completion of treatment using S-303/GSH or after cell culture passages. Treatment using S-303/GSH inactivated high levels of DENV in RBCs to the limit of detection. In combination with previous studies showing the effective inactivation of DENV in plasma and platelets using the licensed amotosalen/UVA system, this study demonstrates that high levels of DENV can be inactivated in all blood components. © 2017 The Authors Transfusion published by Wiley Periodicals, Inc. on behalf of AABB.

Sunlight inactivation of Escherichia coli in waste stabilization microcosms in a sahelian region (Ouagadougou, Burkina Faso).

Science.gov (United States)

Maïga, Ynoussa; Denyigba, Kokou; Wethe, Joseph; Ouattara, Aboubakar Sidiki

2009-02-09

Experiments on sunlight inactivation of Escherichia coli were conducted from November 2006 to June 2007 in eight outdoors microcosms with different depths filled with maturation pond wastewater in order to determine pond depth influence on sunlight inactivation of E. coli. The long-term aim was to maximize sunlight inactivation of waterborne pathogens in waste stabilization ponds (WSPs) in sahelian regions where number of sunny days enable longer exposure of wastewater to sunlight. The inactivation was followed during daylight from 8.00 h to 17.00 h and during the night. Sunlight inactivation rates (K(S)), as a function of cumulative global solar radiation (insolation), were 16 and 24 times higher than the corresponding dark inactivation (K(D)) rates, respectively in cold and warm season. In warm season, E. coli was inactivated far more rapidly. Inactivation of E. coli follows the evolution of radiation during the day. In shallow depth microcosms, E. coli was inactivated far more rapidly than in high depth microcosms. The physical chemical parameters [pH, dissolved oxygen (DO)] of microcosms water were higher in shallow depth microcosms than in high depth microcosms suggesting a synergistic effect of sunlight and these parameters to damage E. coli. To increase the efficiency of the elimination of waterborne bacteria, the use of maturation ponds with intermediate depths (0.4m) would be advisable in view of the high temperatures and thus evaporation recorded in sahelian regions.

Ventral, but not dorsal, hippocampus inactivation impairs reward memory expression and retrieval in contexts defined by proximal cues.

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Riaz, Sadia; Schumacher, Anett; Sivagurunathan, Seyon; Van Der Meer, Matthijs; Ito, Rutsuko

2017-07-01

The hippocampus (HPC) has been widely implicated in the contextual control of appetitive and aversive conditioning. However, whole hippocampal lesions do not invariably impair all forms of contextual processing, as in the case of complex biconditional context discrimination, leading to contention over the exact nature of the contribution of the HPC in contextual processing. Moreover, the increasingly well-established functional dissociation between the dorsal (dHPC) and ventral (vHPC) subregions of the HPC has been largely overlooked in the existing literature on hippocampal-based contextual memory processing in appetitively motivated tasks. Thus, the present study sought to investigate the individual roles of the dHPC and the vHPC in contextual biconditional discrimination (CBD) performance and memory retrieval. To this end, we examined the effects of transient post-acquisition pharmacological inactivation (using a combination of GABA A and GABA B receptor agonists muscimol and baclofen) of functionally distinct subregions of the HPC (CA1/CA3 subfields of the dHPC and vHPC) on CBD memory retrieval. Additional behavioral assays including novelty preference, light-dark box and locomotor activity test were also performed to confirm that the respective sites of inactivation were functionally silent. We observed robust deficits in CBD performance and memory retrieval following inactivation of the vHPC, but not the dHPC. Our data provides novel insight into the differential roles of the ventral and dorsal HPC in reward contextual processing, under conditions in which the context is defined by proximal cues. © 2017 Wiley Periodicals, Inc.

Mirasol PRT system inactivation efficacy evaluated in platelet concentrates by bacteria-contamination model

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Jocić Miodrag

2011-01-01

Full Text Available Background/Aim. Bacterial contamination of blood components, primarily platelet concentrates (PCs, has been identified as one of the most frequent infectious complications in transfusion practice. PC units have a high risk for bacterial growth/multiplication due to their storage at ambient temperature (20 ± 2°C. Consequences of blood contamination could be effectively prevented or reduced by pathogen inactivation systems. The aim of this study was to determine the Mirasol pathogen reduction technology (PRT system efficacy in PCs using an artificial bacteria-contamination model. Methods. According to the ABO blood groups, PC units (n = 216 were pooled into 54 pools (PC-Ps. PC-Ps were divided into three equal groups, with 18 units in each, designed for an artificial bacteria-contamination. Briefly, PC-Ps were contaminated by Staphylococcus epidermidis, Staphylococcus aureus or Escherichia coli in concentrations 102 to 107 colony forming units (CFU per unit. Afterward, PC-Ps were underwent to inactivation by Mirasol PRT system, using UV (l = 265-370 nm activated riboflavin (RB. All PC-Ps were assayed by BacT/Alert Microbial Detection System for CFU quantification before and after the Mirasol treatment. Samples from non-inactivated PC-P units were tested after preparation and immediately following bacterial contamination. Samples from Mirasol treated units were quantified for CFUs one hour, 3 days and 5 days after inactivation. Results. A complete inactivation of all bacteria species was obtained at CFU concentrations of 102 and 103 per PC-P unit through storage/ investigation period. The most effective inactivation (105 CFU per PC-P unit was obtained in Escherichia coli setting. Contrary, inactivation of all the three tested bacteria species was unworkable in concentrations of ≥ 106 CFU per PC-P unit. Conclusion. Efficient inactivation of investigated bacteria types with a significant CFU depletion in PC-P units was obtained - 3 Log for all

Basal forebrain motivational salience signal enhances cortical processing and decision speed

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Sylvina M Raver

2015-10-01

Full Text Available The basal forebrain (BF contains major projections to the cerebral cortex, and plays a well-documented role in arousal, attention, decision-making, and in modulating cortical activity. BF neuronal degeneration is an early event in Alzheimer’s disease and dementias, and occurs in normal cognitive aging. While the BF is best known for its population of cortically projecting cholinergic neurons, the region is anatomically and neurochemically diverse, and also contains prominent populations of non-cholinergic projection neurons. In recent years, increasing attention has been dedicated to these non-cholinergic BF neurons in order to better understand how non-cholinergic BF circuits control cortical processing and behavioral performance. In this review, we focus on a unique population of putative non-cholinergic BF neurons that encodes the motivational salience of stimuli with a robust ensemble bursting response. We review recent studies that describe the specific physiological and functional characteristics of these BF salience-encoding neurons in behaving animals. These studies support the unifying hypothesis whereby BF salience-encoding neurons act as a gain modulation mechanism of the decision-making process to enhance cortical processing of behaviorally relevant stimuli, and thereby facilitate faster and more precise behavioral responses. This function of BF salience-encoding neurons represents a critical component in determining which incoming stimuli warrant an animal’s attention, and is therefore a fundamental and early requirement of behavioral flexibility.

Inactivation of Staphylococcus aureus and Enterococcus faecalis by a direct-current, cold atmospheric-pressure air plasma microjet☆

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Tian, Ye; Sun, Peng; Wu, Haiyan; Bai, Na; Wang, Ruixue; Zhu, Weidong; Zhang, Jue; Liu, Fuxiang

2010-01-01

Objective A direct-current, cold atmospheric-pressure air plasma microjet (PMJ) was performed to inactivate Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis) in air. The process of sterilization and morphology of bacteria was observed. We wish to know the possible inactivation mechanisms of PMJ and explore a potential application in dental and other temperature sensitive treatment. Methods In this study, we employed a direct current, atmospheric pressure, cold air PMJ to inactivate bacterias. Scanning electron microscopy was employed to evaluate the morphology of S. aureus and showed rupture of cell walls after the plasma treatment and Optical emission spectrum (OES) were used to understand the possible inactivation mechanisms of PMJ. Results The inactivation rates could reach 100% in 5 min. When the distance between the exit nozzle of the PMJ device and Petri dish was extended from 1 cm to 3 cm, effective inactivation was also observed with a similar inactivation curve. Conclusion The inactivation of bacteria is attributed to the abundant reactive oxygen and nitrogen species, as well as ultroviolet radiation in the plasma. Different life spans and defensibilities of these killing agents may hold the key to understanding the different inactivation curves at different treatment distances. PMID:23554639

Inactivation of Bmp4 from the Tbx1 Expression Domain Causes Abnormal Pharyngeal Arch Artery and Cardiac Outflow Tract Remodeling

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Nie, Xuguang; Brown, Christopher B.; Wang, Qin; Jiao, Kai

2011-01-01

Maldevelopment of outflow tract and aortic arch arteries is among the most common forms of human congenital heart diseases. Both Bmp4 and Tbx1 are known to play critical roles during cardiovascular development. Expression of these two genes partially overlaps in pharyngeal arch areas in mouse embryos. In this study, we applied a conditional gene inactivation approach to test the hypothesis that Bmp4 expressed from the Tbx1 expression domain plays a critical role for normal development of outflow tract and pharyngeal arch arteries. We showed that inactivation of Bmp4 from Tbx1-expressing cells leads to the spectrum of deformities resembling the cardiovascular defects observed in human DiGeorge syndrome patients. Inactivation of Bmp4 from the Tbx1 expression domain did not cause patterning defects, but affected remodeling of outflow tract and pharyngeal arch arteries. Our further examination revealed that Bmp4 is required for normal recruitment/differentiation of smooth muscle cells surrounding the PAA4 and survival of outflow tract cushion mesenchymal cells. PMID:21123999

Inactivation kinetics and efficiencies of UV-LEDs against Pseudomonas aeruginosa, Legionella pneumophila, and surrogate microorganisms.

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Rattanakul, Surapong; Oguma, Kumiko

2018-03-01

To demonstrate the effectiveness of UV light-emitting diodes (UV-LEDs) to disinfect water, UV-LEDs at peak emission wavelengths of 265, 280, and 300 nm were adopted to inactivate pathogenic species, including Pseudomonas aeruginosa and Legionella pneumophila, and surrogate species, including Escherichia coli, Bacillus subtilis spores, and bacteriophage Qβ in water, compared to conventional low-pressure UV lamp emitting at 254 nm. The inactivation profiles of each species showed either a linear or sigmoidal survival curve, which both fit well with the Geeraerd's model. Based on the inactivation rate constant, the 265-nm UV-LED showed most effective fluence, except for with E. coli which showed similar inactivation rates at 265 and 254 nm. Electrical energy consumption required for 3-log 10 inactivation (E E,3 ) was lowest for the 280-nm UV-LED for all microbial species tested. Taken together, the findings of this study determined the inactivation profiles and kinetics of both pathogenic bacteria and surrogate species under UV-LED exposure at different wavelengths. We also demonstrated that not only inactivation rate constants, but also energy efficiency should be considered when selecting an emission wavelength for UV-LEDs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiation inactivation of T7 phage

International Nuclear Information System (INIS)

Becker, D.; Redpath, J.L.; Grossweiner, L.I.

1978-01-01

The radiation inactivation of T7 phage by 25-MeV electron pulses has been measured in various media containing a wide concentration range of radical scavenging solutes and in the presence of protective and sensitizing agents. The dependence of sensitivity on pulse dose, from 1 mrad to 3.6 krad, is attributed to radical depletion via bimolecular processes. The survival data are analyzed by extending target theory to include diffusive reactions of primary and secondary radicals generated in the medium. It is concluded that OH radicals are the principal primary inactivating species and that secondary radicals from Br - , CNS - , uracil, glucose, ribose, sucrose, tyrosine, and histidine are lethal to some extent. In nutrient broth or 100 mM histidine, psoralen derivatives, Actinomycin D, and Mitomycin C are anoxic sensitizers. It is proposed that the psoralens promote the formation of non-strand break lesions as the sensitization mechanism. The target theory based on diffusional kinetics is applicable to other systems including single cells

X-chromosome inactivation in development and cancer.

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Chaligné, Ronan; Heard, Edith

2014-08-01

X-chromosome inactivation represents an epigenetics paradigm and a powerful model system of facultative heterochromatin formation triggered by a non-coding RNA, Xist, during development. Once established, the inactive state of the Xi is highly stable in somatic cells, thanks to a combination of chromatin associated proteins, DNA methylation and nuclear organization. However, sporadic reactivation of X-linked genes has been reported during ageing and in transformed cells and disappearance of the Barr body is frequently observed in cancer cells. In this review we summarise current knowledge on the epigenetic changes that accompany X inactivation and discuss the extent to which the inactive X chromosome may be epigenetically or genetically perturbed in breast cancer. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

ALTERNATIVE EQUATIONS FOR DYNAMIC BEHAVIOR OF IONIC CHANNEL ACTIVATION AND INACTIVATION GATES

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Mahmut ÖZER

2003-03-01

Full Text Available In this paper, alternative equations for dynamics of ionic channel activation and inactivation gates are proposed based on the path probability method. Dynamic behavior of a voltage-gated ionic channel is modeled by the conventional Hodgkin-Huxley (H-H mathematical formalism. In that model, conductance of the channel is defined in terms of activation and inactivation gates. Dynamics of the activation and inactivation gates is modeled by first-order differential equations dependent on the gate variable and the membrane potential. In the new approach proposed in this study, dynamic behavior of activation and inactivation gates is modeled by a firstorder differential equation dependent on internal energy and membrane potential by using the path probability method which is widely used in statistical physics. The new model doesn't require the time constant and steadystate values which are used explicitly in the H-H model. The numerical results show validity of the proposed method.

Control of cerebral cortical blood flow by stimulation of basal forebrain cholinergic areas in mice.

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Hotta, Harumi; Uchida, Sae; Kagitani, Fusako; Maruyama, Naoki

2011-05-01

We examined whether activity of the nucleus basalis of Meynert (NBM) regulates regional cerebral cortical blood flow (rCBF) in mice, using laser speckle and laser Doppler flowmetry. In anesthetized mice, unilateral focal stimulation, either electrical or chemical, of the NBM increased rCBF of the ipsilateral cerebral cortex in the frontal, parietal and occipital lobes, independent of changes in systemic blood pressure. Most of vasodilative responses to low intensity stimuli (2 times threshold intensity: 2T) were abolished by atropine (a muscarinic cholinergic blocker), whereas responses to higher intensity stimuli (3T) were abolished by atropine and mecamylamine (a nicotinic cholinergic blocker). Blood flow changes were largest when the tip of the electrode was located within the area containing cholinergic neurons shown by choline acetyltransferase-immunocytochemistry. These results suggest that cholinergic projections from basal forebrain neurons in mice cause vasodilation in the ipsilateral cerebral cortex by a combination of muscarinic and nicotinic mechanisms, as previously found in rats and cats.

Statistical learning of recurring sound patterns encodes auditory objects in songbird forebrain.

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Lu, Kai; Vicario, David S

2014-10-07

Auditory neurophysiology has demonstrated how basic acoustic features are mapped in the brain, but it is still not clear how multiple sound components are integrated over time and recognized as an object. We investigated the role of statistical learning in encoding the sequential features of complex sounds by recording neuronal responses bilaterally in the auditory forebrain of awake songbirds that were passively exposed to long sound streams. These streams contained sequential regularities, and were similar to streams used in human infants to demonstrate statistical learning for speech sounds. For stimulus patterns with contiguous transitions and with nonadjacent elements, single and multiunit responses reflected neuronal discrimination of the familiar patterns from novel patterns. In addition, discrimination of nonadjacent patterns was stronger in the right hemisphere than in the left, and may reflect an effect of top-down modulation that is lateralized. Responses to recurring patterns showed stimulus-specific adaptation, a sparsening of neural activity that may contribute to encoding invariants in the sound stream and that appears to increase coding efficiency for the familiar stimuli across the population of neurons recorded. As auditory information about the world must be received serially over time, recognition of complex auditory objects may depend on this type of mnemonic process to create and differentiate representations of recently heard sounds.

Divergent lactate dehydrogenase isoenzyme profile in cellular compartments of primate forebrain structures.

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Duka, Tetyana; Collins, Zachary; Anderson, Sarah M; Raghanti, Mary Ann; Ely, John J; Hof, Patrick R; Wildman, Derek E; Goodman, Morris; Grossman, Lawrence I; Sherwood, Chet C

2017-07-01

The compartmentalization and association of lactate dehydrogenase (LDH) with specific cellular structures (e.g., synaptosomal, sarcoplasmic or mitochondrial) may play an important role in brain energy metabolism. Our previous research revealed that LDH in the synaptosomal fraction shifts toward the aerobic isoforms (LDH-B) among the large-brained haplorhine primates compared to strepsirrhines. Here, we further analyzed the subcellular localization of LDH in primate forebrain structures using quantitative Western blotting and ELISA. We show that, in cytosolic and mitochondrial subfractions, LDH-B expression level was relatively elevated and LDH-A declined in haplorhines compared to strepsirrhines. LDH-B expression in mitochondrial fractions of the neocortex was preferentially increased, showing a particularly significant rise in the ratio of LDH-B to LDH-A in chimpanzees and humans. We also found a significant correlation between the protein levels of LDH-B in mitochondrial fractions from haplorhine neocortex and the synaptosomal LDH-B that suggests LDH isoforms shift from a predominance of A-subunits toward B-subunits as part of a system that spatially buffers dynamic energy requirements of brain cells. Our results indicate that there is differential subcellular compartmentalization of LDH isoenzymes that evolved among different primate lineages to meet the energy requirements in neocortical and striatal cells. Copyright © 2017 Elsevier Inc. All rights reserved.

The amygdala and basal forebrain as a pathway for motivationally guided attention.

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Peck, Christopher J; Salzman, C Daniel

2014-10-08

Visual stimuli associated with rewards attract spatial attention. Neurophysiological mechanisms that mediate this process must register both the motivational significance and location of visual stimuli. Recent neurophysiological evidence indicates that the amygdala encodes information about both of these parameters. Furthermore, the firing rate of amygdala neurons predicts the allocation of spatial attention. One neural pathway through which the amygdala might influence attention involves the intimate and bidirectional connections between the amygdala and basal forebrain (BF), a brain area long implicated in attention. Neurons in the rhesus monkey amygdala and BF were therefore recorded simultaneously while subjects performed a detection task in which the stimulus-reward associations of visual stimuli modulated spatial attention. Neurons in BF were spatially selective for reward-predictive stimuli, much like the amygdala. The onset of reward-predictive signals in each brain area suggested different routes of processing for reward-predictive stimuli appearing in the ipsilateral and contralateral fields. Moreover, neurons in the amygdala, but not BF, tracked trial-to-trial fluctuations in spatial attention. These results suggest that the amygdala and BF could play distinct yet inter-related roles in influencing attention elicited by reward-predictive stimuli. Copyright © 2014 the authors 0270-6474/14/3413757-11$15.00/0.

Modeling of human factor Va inactivation by activated protein C

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Bravo Maria

2012-05-01

Full Text Available Abstract Background Because understanding of the inventory, connectivity and dynamics of the components characterizing the process of coagulation is relatively mature, it has become an attractive target for physiochemical modeling. Such models can potentially improve the design of therapeutics. The prothrombinase complex (composed of the protease factor (FXa and its cofactor FVa plays a central role in this network as the main producer of thrombin, which catalyses both the activation of platelets and the conversion of fibrinogen to fibrin, the main substances of a clot. A key negative feedback loop that prevents clot propagation beyond the site of injury is the thrombin-dependent generation of activated protein C (APC, an enzyme that inactivates FVa, thus neutralizing the prothrombinase complex. APC inactivation of FVa is complex, involving the production of partially active intermediates and “protection” of FVa from APC by both FXa and prothrombin. An empirically validated mathematical model of this process would be useful in advancing the predictive capacity of comprehensive models of coagulation. Results A model of human APC inactivation of prothrombinase was constructed in a stepwise fashion by analyzing time courses of FVa inactivation in empirical reaction systems with increasing number of interacting components and generating corresponding model constructs of each reaction system. Reaction mechanisms, rate constants and equilibrium constants informing these model constructs were initially derived from various research groups reporting on APC inactivation of FVa in isolation, or in the presence of FXa or prothrombin. Model predictions were assessed against empirical data measuring the appearance and disappearance of multiple FVa degradation intermediates as well as prothrombinase activity changes, with plasma proteins derived from multiple preparations. Our work integrates previously published findings and through the cooperative

Inactivation of carotenoid-producing and albino strains of Neurospora crassa by visible light, blacklight, and ultraviolet radiation

International Nuclear Information System (INIS)

Blanc, P.L.; Tuveson, R.W.; Sargent, M.L.

1976-01-01

Suspensions of Neurospora crassa conidia were inactivated by blacklight (BL) radiation (300 to 425 nm) in the absence of exogenous photosensitizing compounds. Carotenoid-containing wild-type conidia were less sensitive to BL radiation than albino conidia, showing a dose enhancement factor (DEF) of 1.2 for dose levels resulting in less than 10 percent survival. The same strains were about equally sensitive to shortwave ultraviolet (uv) inactivation. The kinetics of BL inactivation are similar to those of photodynamic inactivation by visible light in the presence of a photosensitizing dye (methylene blue). Only limited inactivation by visible light in the absence of exogenous photosensitizers was observed. BL and UV inactivations are probably caused by different mechanisms since wild-type conidia are only slightly more resistant to BL radiation (DEF = 1.2 at 1.0 percent survival) than are conidia from a uv-sensitive strain (upr-1, uvs-3). The BL-induced lethal lesions are probably not cyclobutyl pyrimidine dimers since BL-inactivated Haemophilus influenzae transforming deoxyribonucleic acid is not photoreactivated by N. crassa wild-type enzyme extracts, whereas uv-inactivated transforming deoxyribonucleic acid is photoreactivable with this treatment

Inactivation of Listeria monocytogenes in milk by pulsed electric field.

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Reina, L D; Jin, Z T; Zhang, Q H; Yousef, A E

1998-09-01

Pasteurized whole, 2%, and skim milk were inoculated with Listeria monocytogenes Scott A and treated with high-voltage pulsed electric field (PEF). The effects of milk composition (fat content) and PEF parameters (electric field strength, treatment time, and treatment temperature) on the inactivation of the bacterium were studied. No significant differences were observed in the inactivation of L. monocytogenes Scott A in three types of milk by PEF treatment. With treatment at 25 degrees C, 1- to 3-log reductions of L. monocytogenes were observed. PEF lethal effect was a function of field strength and treatment time. Higher field strength or longer treatment time resulted in a greater reduction of viable cells. A 4-log reduction of the bacterium was obtained by increasing the treatment temperature to 50 degrees C. Results indicate that the use of a high-voltage PEF is a promising technology for inactivation of foodborne pathogens.

Synergistic inactivation of anaerobic wastewater biofilm by free nitrous acid and hydrogen peroxide

International Nuclear Information System (INIS)

Jiang, Guangming; Yuan, Zhiguo

2013-01-01

Highlights: ► H 2 O 2 greatly enhances the inactivation of microorganisms in biofilms by FNA. ► About 2-log of inactivation of biofilm microbes was achieved by FNA + H 2 O 2 . ► FNA + H 2 O 2 reduced sulfide production and detached biofilm in reactors. -- Abstract: Free nitrous acid (FNA) was recently revealed to be a strong biocide for microbes in anaerobic biofilm, achieving approximately 1-log (90%) inactivation at a concentration of 0.2–0.3 mgHNO 2 -N/L with an exposure time longer than 6 h. The combined biocidal effects of FNA and hydrogen peroxide (H 2 O 2 ) on anaerobic wastewater biofilm are investigated in this study. H 2 O 2 greatly enhances the inactivation of microorganisms by FNA. About 2-log (99%) of microbial inactivation was achieved when biofilms were exposed to FNA at 0.2 mgN/L or above and H 2 O 2 at 30 mg/L or above for 6 h or longer. It was found, through response surface methodology and ridge analysis, that FNA is the primary inactivation agent and H 2 O 2 enhances its efficiency. The loss and the subsequent slow recovery of biological activity in biofilm reactors subjected to FNA and H 2 O 2 dosing confirmed that the chemical combination could achieve higher microbial inactivation than with FNA alone. Reaction simulation shows that intermediates of reactions between FNA and H 2 O 2 , like peroxynitrite and nitrogen dioxide, would be produced at elevated levels and are likely responsible for the synergism between FNA and H 2 O 2 . The combination of FNA and H 2 O 2 could potentially provide an effective solution to sewer biofilm control

Synergistic inactivation of anaerobic wastewater biofilm by free nitrous acid and hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Jiang, Guangming, E-mail: gjiang@awmc.uq.edu.au [Advanced Water Management Centre, Gehrmann Building, Research Road, The University of Queensland, St. Lucia, Queensland 4072 (Australia); Yuan, Zhiguo, E-mail: zhiguo@awmc.uq.edu.au [Advanced Water Management Centre, Gehrmann Building, Research Road, The University of Queensland, St. Lucia, Queensland 4072 (Australia)

2013-04-15

Highlights: ► H{sub 2}O{sub 2} greatly enhances the inactivation of microorganisms in biofilms by FNA. ► About 2-log of inactivation of biofilm microbes was achieved by FNA + H{sub 2}O{sub 2}. ► FNA + H{sub 2}O{sub 2} reduced sulfide production and detached biofilm in reactors. -- Abstract: Free nitrous acid (FNA) was recently revealed to be a strong biocide for microbes in anaerobic biofilm, achieving approximately 1-log (90%) inactivation at a concentration of 0.2–0.3 mgHNO{sub 2}-N/L with an exposure time longer than 6 h. The combined biocidal effects of FNA and hydrogen peroxide (H{sub 2}O{sub 2}) on anaerobic wastewater biofilm are investigated in this study. H{sub 2}O{sub 2} greatly enhances the inactivation of microorganisms by FNA. About 2-log (99%) of microbial inactivation was achieved when biofilms were exposed to FNA at 0.2 mgN/L or above and H{sub 2}O{sub 2} at 30 mg/L or above for 6 h or longer. It was found, through response surface methodology and ridge analysis, that FNA is the primary inactivation agent and H{sub 2}O{sub 2} enhances its efficiency. The loss and the subsequent slow recovery of biological activity in biofilm reactors subjected to FNA and H{sub 2}O{sub 2} dosing confirmed that the chemical combination could achieve higher microbial inactivation than with FNA alone. Reaction simulation shows that intermediates of reactions between FNA and H{sub 2}O{sub 2}, like peroxynitrite and nitrogen dioxide, would be produced at elevated levels and are likely responsible for the synergism between FNA and H{sub 2}O{sub 2}. The combination of FNA and H{sub 2}O{sub 2} could potentially provide an effective solution to sewer biofilm control.

Immunogenicity of commercial, formaldehyde and binary ethylenimine inactivated Newcastle disease virus vaccines in specific pathogen free chickens

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Razmaraii, N.

2012-06-01

Full Text Available Newcastle disease (ND is one of the most important diseases that affect birds; the epizootic nature of the disease has caused severe economic losses in the poultry industry worldwide. In this experiment ND virus (NDV was inactivated by two different chemicals binary ethylenimine (BEI and formaldehyde. Formaldehyde was used at 0.1%, while BEI was used at concentrations of 1 to 4 mM. NDV inactivation with BEI was done in various incubation temperatures and periods and the best result (30 °C, 4 mM BEI and 21 hrs treatment used as an experimental vaccine. Prepared inactivated NDV vaccines and a commercial vaccine were tested for their efficiency in generating humoral immune response in different groups of specific pathogen free (SPF chicks. Test groups received 0.2 ml formaldehyde inactivated NDV (NDVF, BEI inactivated NDV (NDVEI and Razi institute produced NDV vaccine (NDVR subcutaneously respectively. HI Log 2 total mean titer of NDVEI group (8.42 ± 0.12 were significantly higher than NDVF (7.64 ± 0.16 and NDVR (7.86 ± 0.11 groups (p<0.05. BEI-inactivated vaccine gave higher antibody titers than formaldehyde-inactivated vaccine and preserves both structural integrity and antigenicity of the virus. Thus, it might be possible to use these compounds as an inactivator agent for commercial NDV inactivated vaccines in future.

Domain IV voltage-sensor movement is both sufficient and rate limiting for fast inactivation in sodium channels.

Science.gov (United States)

Capes, Deborah L; Goldschen-Ohm, Marcel P; Arcisio-Miranda, Manoel; Bezanilla, Francisco; Chanda, Baron

2013-08-01

Voltage-gated sodium channels are critical for the generation and propagation of electrical signals in most excitable cells. Activation of Na(+) channels initiates an action potential, and fast inactivation facilitates repolarization of the membrane by the outward K(+) current. Fast inactivation is also the main determinant of the refractory period between successive electrical impulses. Although the voltage sensor of domain IV (DIV) has been implicated in fast inactivation, it remains unclear whether the activation of DIV alone is sufficient for fast inactivation to occur. Here, we functionally neutralize each specific voltage sensor by mutating several critical arginines in the S4 segment to glutamines. We assess the individual role of each voltage-sensing domain in the voltage dependence and kinetics of fast inactivation upon its specific inhibition. We show that movement of the DIV voltage sensor is the rate-limiting step for both development and recovery from fast inactivation. Our data suggest that activation of the DIV voltage sensor alone is sufficient for fast inactivation to occur, and that activation of DIV before channel opening is the molecular mechanism for closed-state inactivation. We propose a kinetic model of sodium channel gating that can account for our major findings over a wide voltage range by postulating that DIV movement is both necessary and sufficient for fast inactivation.

Reactive hydroxyl radical-driven oral bacterial inactivation by radio frequency atmospheric plasma

International Nuclear Information System (INIS)

Kang, Sung Kil; Lee, Jae Koo; Choi, Myeong Yeol; Koo, Il Gyo; Kim, Paul Y.; Kim, Yoonsun; Kim, Gon Jun; Collins, George J.; Mohamed, Abdel-Aleam H.

2011-01-01

We demonstrated bacterial (Streptococcus mutans) inactivation by a radio frequency power driven atmospheric pressure plasma torch with H 2 O 2 entrained in the feedstock gas. Optical emission spectroscopy identified substantial excited state OH generation inside the plasma and relative OH formation was verified by optical absorption. The bacterial inactivation rate increased with increasing OH generation and reached a maximum 5-log 10 reduction with 0.6%H 2 O 2 vapor. Generation of large amounts of toxic ozone is drawback of plasma bacterial inactivation, thus it is significant that the ozone concentration falls within recommended safe allowable levels with addition of H 2 O 2 vapor to the plasma.

The inactivating and mutagenic effect of hydroxylamine on bacteriophage φX174

NARCIS (Netherlands)

Pol, J.H. van de; Arkel, G.A. van

1965-01-01

The inactivation of bacteriophage ΦXI74 by the mutagenic agents nitrous acid and ultraviolet irradiation proceeds according to a single-hit kinetics. However, treatment of purified ΦXI74 by hydroxylamine (HA) at pH 6 and 25° results in an inactivation that is not strictly exponential. The

Radiation-induced inactivation of bovine liver catalase in nitrous oxide-saturated solutions

International Nuclear Information System (INIS)

Gebicka, L.; Metodiewa, D.

1988-01-01

Radiation-induced inactivation of catalase by . OH/H . radicals was studied. It was found that inactivation yield of catalase depended on the dose. Optical spectrum of irradiated catalase showed that no redox processes in active site of enzyme occurred as a result of . OH/H . interaction. (author) 19 refs.; 3 figs

Clostridium botulinum neurotoxin type B is heat-stable in milk and not inactivated by pasteurization.

Science.gov (United States)

Rasooly, Reuven; Do, Paula M

2010-12-08

Foodborne botulism is caused by the ingestion of foods containing botulinum neurotoxins (BoNTs). To study the heat stability of Clostridium botulinum neurotoxins, we needed to measure and compare the activity of botulinum neurotoxins, serotypes A and B, under various pasteurization conditions. Currently, the only accepted assay to detect active C. botulinum neurotoxin is an in vivo mouse bioassay, which raises ethical concerns with regard to the use of experimental animals. In this study, noninvasive methods were used to simultaneously detect and distinguish between active BoNT serotypes A and B in one reaction and sample. We developed an enzymatic activity assay employing internally quenched fluorogenic peptides corresponding to SNAP-25, for BoNT-A, and VAMP2, for BoNT-B, as an alternative method to the mouse bioassay. Because each peptide is labeled with different fluorophores, we were able to distinguish between these two toxins. We used this method to analyze the heat stability of BoNT-A and BoNT-B. This study reports that conventional milk pasteurization (63 °C, 30 min) inactivated BoNT serotype A; however, serotype B is heat-stable in milk and not inactivated by pasteurization. Using this activity assay, we also showed that the commonly used food processes such as acidity and pasteurization, which are known to inhibit C. botulinum growth and toxin production, are more effective in inactivating BoNT serotype A than serotype B when conventional pasteurization (63 °C, 30 min) is used.

Lack of correlation between virus barosensitivity and the presence of a viral envelope during inactivation of human rotavirus, vesicular stomatitis virus, and avian metapneumovirus by high-pressure processing.

Science.gov (United States)

Lou, Fangfei; Neetoo, Hudaa; Li, Junan; Chen, Haiqiang; Li, Jianrong

2011-12-01

High-pressure processing (HPP) is a nonthermal technology that has been shown to effectively inactivate a wide range of microorganisms. However, the effectiveness of HPP on inactivation of viruses is relatively less well understood. We systematically investigated the effects of intrinsic (pH) and processing (pressure, time, and temperature) parameters on the pressure inactivation of a nonenveloped virus (human rotavirus [HRV]) and two enveloped viruses (vesicular stomatitis virus [VSV] and avian metapneumovirus [aMPV]). We demonstrated that HPP can efficiently inactivate all tested viruses under optimal conditions, although the pressure susceptibilities and the roles of temperature and pH substantially varied among these viruses regardless of the presence of a viral envelope. We found that VSV was much more stable than most food-borne viruses, whereas aMPV was highly susceptible to HPP. When viruses were held for 2 min under 350 MPa at 4°C, 1.1-log, 3.9-log, and 5.0-log virus reductions were achieved for VSV, HRV, and aMPV, respectively. Both VSV and aMPV were more susceptible to HPP at higher temperature and lower pH. In contrast, HRV was more easily inactivated at higher pH, although temperature did not have a significant impact on inactivation. Furthermore, we demonstrated that the damage of virion structure by disruption of the viral envelope and/or capsid is the primary mechanism underlying HPP-induced viral inactivation. In addition, VSV glycoprotein remained antigenic although VSV was completely inactivated. Taken together, our findings suggest that HPP is a promising technology to eliminate viral contaminants in high-risk foods, water, and other fomites.

Electron beam inactivation of Tulane virus on fresh produce, and mechanism of inactivation of human norovirus surrogates by electron beam irradiation.

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Predmore, Ashley; Sanglay, Gabriel C; DiCaprio, Erin; Li, Jianrong; Uribe, R M; Lee, Ken

2015-04-02

Ionizing radiation, whether by electron beams or gamma rays, is a non-thermal processing technique used to improve the microbial safety and shelf-life of many different food products. This technology is highly effective against bacterial pathogens, but data on its effect against foodborne viruses is limited. A mechanism of viral inactivation has been proposed with gamma irradiation, but no published study discloses a mechanism for electron beam (e-beam). This study had three distinct goals: 1) evaluate the sensitivity of a human norovirus surrogate, Tulane virus (TV), to e-beam irradiation in foods, 2) compare the difference in sensitivity of TV and murine norovirus (MNV-1) to e-beam irradiation, and 3) determine the mechanism of inactivation of these two viruses by e-beam irradiation. TV was reduced from 7 log10 units to undetectable levels at target doses of 16 kGy or higher in two food matrices (strawberries and lettuce). MNV-1 was more resistant to e-beam treatment than TV. At target doses of 4 kGy, e-beam provided a 1.6 and 1.2 log reduction of MNV-1 in phosphate buffered saline (PBS) and Dulbecco's Modified Eagle Medium (DMEM), compared to a 1.5 and 1.8 log reduction of TV in PBS and Opti-MEM, respectively. Transmission electron microscopy revealed that increased e-beam doses negatively affected the structure of both viruses. Analysis of viral proteins by SDS-PAGE found that irradiation also degraded viral proteins. Using RT-PCR, irradiation was shown to degrade viral genomic RNA. This suggests that the mechanism of inactivation of e-beam was likely the same as gamma irradiation as the damage to viral constituents led to inactivation. Copyright © 2014 Elsevier B.V. All rights reserved.

Inactivation of natural enteric bacteria in real municipal wastewater by solar photo-Fenton at neutral pH.

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Ortega-Gómez, E; Esteban García, B; Ballesteros Martín, M M; Fernández Ibáñez, P; Sánchez Pérez, J A

2014-10-15

This study analyses the use of the solar photo-Fenton treatment in compound parabolic collector photo-reactors at neutral pH for the inactivation of wild enteric Escherichia coli and total coliform present in secondary effluents of a municipal wastewater treatment plant (SEWWTP). Control experiments were carried out to find out the individual effects of mechanical stress, pH, reactants concentration, and UVA radiation as well as the combined effects of UVA-Fe and UVA-H2O2. The synergistic germicidal effect of solar-UVA with 50 mg L(-1) of H2O2 led to complete disinfection (up to the detection limit) of total coliforms within 120 min. The disinfection process was accelerated by photo-Fenton, achieving total inactivation in 60 min reducing natural bicarbonate concentration found in the SEWWTP from 250 to 100 mg L(-1) did not give rise to a significant enhancement in bacterial inactivation. Additionally, the effect of hydrogen peroxide and iron dosage was evaluated. The best conditions were 50 mg L(-1) of H2O2 and 20 mg L(-1) of Fe(2+). Due to the variability of the SEWWTP during autumn and winter seasons, the inactivation kinetic constant varied between 0.07 ± 0.04 and 0.17 ± 0.04 min(-1). Moreover, the water treated by solar photo-Fenton fulfilled the microbiological quality requirement for wastewater reuse in irrigation as per the WHO guidelines and in particular for Spanish legislation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Patulin reduction in apple juice by inactivated Alicyclobacillus spp.

Science.gov (United States)

Yuan, Y; Wang, X; Hatab, S; Wang, Z; Wang, Y; Luo, Y; Yue, T

2014-12-01

This study aimed to investigate the reduction of patulin (PAT) in apple juice by 12 inactivated Alicyclobacillus strains. The reduction rate of PAT by each strain was determined by high-performance liquid chromatography (HPLC). The results indicated that the removal of PAT was strain specific. Alicyclobacillus acidoterrestris 92 and A. acidoterrestris 96 were the most effective ones among the 12 tested strains in the removal of PAT. Therefore, these two strains were selected to study the effects of incubation time, initial PAT concentration and bacteria powder amount on PAT removal abilities of Alicyclobacillus. The highest PAT reduction rates of 88·8 and 81·6% were achieved after 24-h incubation with initial PAT concentration of 100 μg l(-1) and bacteria powder amount of 40 g l(-1) , respectively. Moreover, it was found that the treatment by these 12 inactivated Alicyclobacillus strains had no negative effect on the quality parameters of apple juice. Similar assays were performed in supermarket apple juice, where inactivated Alicyclobacillus cells could efficiently reduce PAT content. Taken together, these data suggest the possible application of this strategy as a means to detoxify PAT-contaminated juices. Inactivated Alicyclobacillus cells can efficiently reduce patulin concentration in apple juice. It provides a theoretical foundation for recycling of Alicyclobacillus cells from spoiled apple juice to reduce the source of pollution and the cost of juice industry. This is the first report on the use of Alicyclobacillus to remove patulin from apple juice. © 2014 The Society for Applied Microbiology.

Susceptibility of glucokinase-MODY mutants to inactivation by oxidative stress in pancreatic β-cells.

Science.gov (United States)

Cullen, Kirsty S; Matschinsky, Franz M; Agius, Loranne; Arden, Catherine

2011-12-01

The posttranslational regulation of glucokinase (GK) differs in hepatocytes and pancreatic β-cells. We tested the hypothesis that GK mutants that cause maturity-onset diabetes of the young (GK-MODY) show compromised activity and posttranslational regulation in β-cells. Activity and protein expression of GK-MODY and persistent hyperinsulinemic hypoglycemia of infancy (PHHI) mutants were studied in β-cell (MIN6) and non-β-cell (H4IIE) models. Binding of GK to phosphofructo-2-kinase, fructose-2,6-bisphosphatase (PFK2/FBPase2) was studied by bimolecular fluorescence complementation in cell-based models. Nine of 11 GK-MODY mutants that have minimal effect on enzyme kinetics in vitro showed decreased specific activity relative to wild type when expressed in β-cells. A subset of these were stable in non-β-cells but showed increased inactivation in conditions of oxidative stress and partial reversal of inactivation by dithiothreitol. Unlike the GK-MODY mutants, four of five GK-PHHI mutants had similar specific activity to wild type and Y214C had higher activity than wild type. The GK-binding protein PFK2/FBPase2 protected wild-type GK from oxidative inactivation and the decreased stability of GK-MODY mutants correlated with decreased interaction with PFK2/FBPase2. Several GK-MODY mutants show posttranslational defects in β-cells characterized by increased susceptibility to oxidative stress and/or protein instability. Regulation of GK activity through modulation of thiol status may be a physiological regulatory mechanism for the control of GK activity in β-cells.

Inhibition of host cell protein synthesis by UV-inactivated poliovirus

International Nuclear Information System (INIS)

Helentjaris, T.; Ehrenfeld, E.

1977-01-01

The ability of poliovirus that was irradiated with UV light at energies up to 2,160 ergs/mm 2 to subsequently inhibit host cell protein synthesis was measured. The inactivation of the host cell shutoff function followed one-hit kinetics. Increasing irradiation did not affect the rate of inhibition until the multiplicity of infection after irradiation was reduced to approximately 1 PFU/cell. At higher functional multiplicities, the rate was unchanged, but an increasing lag before the onset of inhibition was observed with increasing irradiation. The energy levels required to inactivate virus-induced inhibition of host cell protein synthesis suggest that damage to virus RNA rather than to virus capsid proteins is responsible for the loss of function. When the inactivation of host cell shutoff was compared with the inactivation of other viral functions by UV irradiation, it correlated exactly with the loss of infectivity but not with other viral functions measured. Guanidine treatment, which prevents detectable viral RNA and protein synthesis, completely inhibited host cell shutoff by low multiplicities of unirradiated virus infection but not higher multiplicities. When a high multiplicity of virus was first reduced to a low titer by irradiation, host cell shutoff was still evident in the presence of guanidine. The results demonstrate that the complete inhibition of host cell protein synthesis can be accomplished by one infectious viral genome per cell

Inactivation of human norovirus using chemical sanitizers.

Science.gov (United States)

Kingsley, David H; Vincent, Emily M; Meade, Gloria K; Watson, Clytrice L; Fan, Xuetong

2014-02-03

The porcine gastric mucin binding magnetic bead (PGM-MB) assay was used to evaluate the ability of chlorine, chlorine dioxide, peroxyacetic acid, hydrogen peroxide, and trisodium phosphate to inactivate human norovirus within 10% stool filtrate. One-minute free chlorine treatments at concentrations of 33 and 189 ppm reduced virus binding in the PGM-MB assay by 1.48 and 4.14 log₁₀, respectively, suggesting that chlorine is an efficient sanitizer for inactivation of human norovirus (HuNoV). Five minute treatments with 5% trisodium phosphate (pH~12) reduced HuNoV binding by 1.6 log₁₀, suggesting that TSP, or some other high pH buffer, could be used to treat food and food contact surfaces to reduce HuNoV. One minute treatments with 350 ppm chlorine dioxide dissolved in water did not reduce PGM-MB binding, suggesting that the sanitizer may not be suitable for HuNoV inactivation in liquid form. However a 60-min treatment with 350 ppm chlorine dioxide did reduce human norovirus by 2.8 log₁₀, indicating that chlorine dioxide had some, albeit limited, activity against HuNoV. Results also suggest that peroxyacetic acid has limited effectiveness against human norovirus, since 1-min treatments with up to 195 ppm reduced human norovirus binding by chlorine (sodium hypochlorite) as a HuNoV disinfectant wherever possible. Copyright © 2013. Published by Elsevier B.V.

Inactivation of STAT3 Signaling Impairs Hair Cell Differentiation in the Developing Mouse Cochlea.

Science.gov (United States)

Chen, Qianqian; Quan, Yizhou; Wang, Naitao; Xie, Chengying; Ji, Zhongzhong; He, Hao; Chai, Renjie; Li, Huawei; Yin, Shankai; Chin, Y Eugene; Wei, Xunbin; Gao, Wei-Qiang

2017-07-11

Although STAT3 signaling is demonstrated to regulate sensory cell differentiation and regeneration in the zebrafish, its exact role is still unclear in mammalian cochleae. Here, we report that STAT3 and its activated form are specifically expressed in hair cells during mouse cochlear development. Importantly, conditional cochlear deletion of Stat3 leads to an inhibition on hair cell differentiation in mice in vivo and in vitro. By cell fate analysis, inactivation of STAT3 signaling shifts the cell division modes from asymmetric to symmetric divisions from supporting cells. Moreover, inhibition of Notch signaling stimulates STAT3 phosphorylation, and inactivation of STAT3 signaling attenuates production of supernumerary hair cells induced by a Notch pathway inhibitor. Our findings highlight an important role of the STAT3 signaling during mouse cochlear hair cell differentiation and may have clinical implications for the recovery of hair cell loss-induced hearing impairment. Copyright © 2017 International Society for Stem Cell Research. Published by Elsevier Inc. All rights reserved.

Inactivation of STAT3 Signaling Impairs Hair Cell Differentiation in the Developing Mouse Cochlea

Directory of Open Access Journals (Sweden)

Qianqian Chen

2017-07-01

Full Text Available Although STAT3 signaling is demonstrated to regulate sensory cell differentiation and regeneration in the zebrafish, its exact role is still unclear in mammalian cochleae. Here, we report that STAT3 and its activated form are specifically expressed in hair cells during mouse cochlear development. Importantly, conditional cochlear deletion of Stat3 leads to an inhibition on hair cell differentiation in mice in vivo and in vitro. By cell fate analysis, inactivation of STAT3 signaling shifts the cell division modes from asymmetric to symmetric divisions from supporting cells. Moreover, inhibition of Notch signaling stimulates STAT3 phosphorylation, and inactivation of STAT3 signaling attenuates production of supernumerary hair cells induced by a Notch pathway inhibitor. Our findings highlight an important role of the STAT3 signaling during mouse cochlear hair cell differentiation and may have clinical implications for the recovery of hair cell loss-induced hearing impairment.

Pulsed-light inactivation of pathogenic and spoilage bacteria on cheese surface.

Science.gov (United States)

Proulx, J; Hsu, L C; Miller, B M; Sullivan, G; Paradis, K; Moraru, C I

2015-09-01

Cheese products are susceptible to postprocessing cross-contamination by bacterial surface contamination during slicing, handling, or packaging, which can lead to food safety issues and significant losses due to spoilage. This study examined the effectiveness of pulsed-light (PL) treatment on the inactivation of the spoilage microorganism Pseudomonas fluorescens, the nonenterohemorrhagic Escherichia coli ATCC 25922 (nonpathogenic surrogate of Escherichia coli O157:H7), and Listeria innocua (nonpathogenic surrogate of Listeria monocytogenes) on cheese surface. The effects of inoculum level and cheese surface topography and the presence of clear polyethylene packaging were evaluated in a full factorial experimental design. The challenge microorganisms were grown to early stationary phase and subsequently diluted to reach initial inoculum levels of either 5 or 7 log cfu/slice. White Cheddar and process cheeses were cut into 2.5×5 cm slices, which were spot-inoculated with 100 µL of bacterial suspension. Inoculated cheese samples were exposed to PL doses of 1.02 to 12.29 J/cm(2). Recovered survivors were enumerated by standard plate counting or the most probable number technique, as appropriate. The PL treatments were performed in triplicate and data were analyzed using a general linear model. Listeria innocua was the least sensitive to PL treatment, with a maximum inactivation level of 3.37±0.2 log, followed by P. fluorescens, with a maximum inactivation of 3.74±0.8 log. Escherichia coli was the most sensitive to PL, with a maximum reduction of 5.41±0.1 log. All PL inactivation curves were nonlinear, and inactivation reached a plateau after 3 pulses (3.07 J/cm(2)). The PL treatments through UV-transparent packaging and without packaging consistently resulted in similar inactivation levels. This study demonstrates that PL has strong potential for decontamination of the cheese surface. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc

Inactivation by gamma irradiation of animal viruses in simulated laboratory effluent

International Nuclear Information System (INIS)

Thomas, F.C.; Ouwerkerk, T.; McKercher, P.

1982-01-01

Several animal viruses were treated with gamma radiation from a 60 Co source under conditions which might be found in effluent from an animal disease laboratory. Swine vesicular disease virus, vesicular stomatitis virus, and blue-tongue virus were irradiated in tissues from experimentally infected animals. Pseudorabies virus, fowl plague virus, swine vesicular disease virus, and vesicular stomatitis virus were irradiated in liquid animal feces. All were tested in animals and in vitro. The D 10 values, that is, the doses required to reduce infectivity by 1 log 10 , were not apparently different from those expected from predictions based on other data and theoretical considerations. The existence of the viruses in pieces of tissues or in liquid feces made no differences in the efficacy of the gamma radiation for inactivating them. Under the ''worst case'' conditions (most protective for virus) simulated in this study, no infectious agents would survive 4.0 Mrads

Inactivation of pyruvate dehydrogenase kinase 2 by mitochondrial reactive oxygen species.

Science.gov (United States)

Hurd, Thomas R; Collins, Yvonne; Abakumova, Irina; Chouchani, Edward T; Baranowski, Bartlomiej; Fearnley, Ian M; Prime, Tracy A; Murphy, Michael P; James, Andrew M

2012-10-12

Reactive oxygen species are byproducts of mitochondrial respiration and thus potential regulators of mitochondrial function. Pyruvate dehydrogenase kinase 2 (PDHK2) inhibits the pyruvate dehydrogenase complex, thereby regulating entry of carbohydrates into the tricarboxylic acid (TCA) cycle. Here we show that PDHK2 activity is inhibited by low levels of hydrogen peroxide (H(2)O(2)) generated by the respiratory chain. This occurs via reversible oxidation of cysteine residues 45 and 392 on PDHK2 and results in increased pyruvate dehydrogenase complex activity. H(2)O(2) derives from superoxide (O(2)(.)), and we show that conditions that inhibit PDHK2 also inactivate the TCA cycle enzyme, aconitase. These findings suggest that under conditions of high mitochondrial O(2)(.) production, such as may occur under nutrient excess and low ATP demand, the increase in O(2)() and H(2)O(2) may provide feedback signals to modulate mitochondrial metabolism.

Dysfunction of the RAR/RXR signaling pathway in the forebrain impairs hippocampal memory and synaptic plasticity

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Nomoto Masanori

2012-02-01

Full Text Available Abstract Background Retinoid signaling pathways mediated by retinoic acid receptor (RAR/retinoid × receptor (RXR-mediated transcription play critical roles in hippocampal synaptic plasticity. Furthermore, recent studies have shown that treatment with retinoic acid alleviates age-related deficits in hippocampal long-term potentiation (LTP and memory performance and, furthermore, memory deficits in a transgenic mouse model of Alzheimer's disease. However, the roles of the RAR/RXR signaling pathway in learning and memory at the behavioral level have still not been well characterized in the adult brain. We here show essential roles for RAR/RXR in hippocampus-dependent learning and memory. In the current study, we generated transgenic mice in which the expression of dominant-negative RAR (dnRAR could be induced in the mature brain using a tetracycline-dependent transcription factor and examined the effects of RAR/RXR loss. Results The expression of dnRAR in the forebrain down-regulated the expression of RARβ, a target gene of RAR/RXR, indicating that dnRAR mice exhibit dysfunction of the RAR/RXR signaling pathway. Similar with previous findings, dnRAR mice displayed impaired LTP and AMPA-mediated synaptic transmission in the hippocampus. More importantly, these mutant mice displayed impaired hippocampus-dependent social recognition and spatial memory. However, these deficits of LTP and memory performance were rescued by stronger conditioning stimulation and spaced training, respectively. Finally, we found that pharmacological blockade of RARα in the hippocampus impairs social recognition memory. Conclusions From these observations, we concluded that the RAR/RXR signaling pathway greatly contributes to learning and memory, and LTP in the hippocampus in the adult brain.

MPLEx: a method for simultaneous pathogen inactivation and extraction of samples for multi-omics profiling

Energy Technology Data Exchange (ETDEWEB)

Burnum-Johnson, Kristin E.; Kyle, Jennifer E.; Eisfeld, Amie J.; Casey, Cameron P.; Stratton, Kelly G.; Gonzalez, Juan F.; Habyarimana, Fabien; Negretti, Nicholas M.; Sims, Amy C.; Chauhan, Sadhana; Thackray, Larissa B.; Halfmann, Peter J.; Walters, Kevin B.; Kim, Young-Mo; Zink, Erika M.; Nicora, Carrie D.; Weitz, Karl K.; Webb-Robertson, Bobbie-Jo M.; Nakayasu, Ernesto S.; Ahmer, Brian; Konkel, Michael E.; Motin, Vladimir; Baric, Ralph S.; Diamond, Michael S.; Kawaoka, Yoshihiro; Waters, Katrina M.; Smith, Richard D.; Metz, Thomas O.

2017-01-01

The continued emergence and spread of infectious agents is of increasing concern due to increased population growth and the associated increased livestock production to meet food demands, increased urbanization and land-use changes, and greater travel. A systems biology approach to infectious disease research can significantly advance our understanding of host-pathogen relationships and facilitate the development of new therapies and vaccines. Molecular characterization of infectious samples outside of appropriate biosafety containment can only take place subsequent to pathogen inactivation. Herein, we describe a modified Folch extraction using chloroform/methanol that facilitates the molecular characterization of infectious samples by enabling simultaneous pathogen inactivation and extraction of proteins, metabolites, and lipids for subsequent mass spectrometry-based multi-omics measurements. This metabolite, protein and lipid extraction (MPLEx) method resulted in complete inactivation of bacterial and viral pathogens with exposed lipid membranes, including Yersinia pestis, Salmonella Typhimurium, and Campylobacter jejuni in pure culture, and Yersinia pestis, Campylobacter jejuni, West Nile, MERS-CoV, Ebola, and influenza H7N9 viruses in infection studies. Partial inactivation was observed for pathogens without exposed lipid membranes including 99.99% inactivation of community-associated methicillin-resistant Staphylococcus aureus, 99.6% and >99% inactivation of Clostridium difficile spores and vegetative cells, respectively, and 50% inactivation of adenovirus type 5. To demonstrate that MPLEx yields biomaterial of sufficient quality for subsequent multi-omics analyses, we highlight select proteomics, metabolomics and lipidomics data from human epithelial lung cells infected with wild-type and mutant forms of influenza H7N9. We believe that MPLEx will facilitate systems biology studies of infectious samples by enabling simultaneous pathogen inactivation and multi

Inactivation of Listeria innocua in skim milk by pulsed electric fields and nisin.

Science.gov (United States)

Calderón-Miranda, M L; Barbosa-Cánovas, G V; Swanson, B G

1999-10-01

Pulsed electric fields (PEF) is an emerging nonthermal processing technology used to inactivate microorganisms in liquid foods such as milk. PEF results in loss of cell membrane functionality that leads to inactivation of the microorganism. There are many processes that aid in the stability and safety of foods. The combination of different preservation factors, such as nisin and PEF, to control microorganisms should be explored. The objective of this research was to study the inactivation of Listeria innocua suspended in skim milk by PEF as well as the sensitization of PEF treated L. innocua to nisin. The selected electric field intensity was 30, 40 and 50 kV/cm and the number of pulses applied was 10.6, 21.3 and 32. The sensitization exhibited by PEF treated L. innocua to nisin was assessed for 10 or 100 IU nisin/ml. A progressive decrease in the population of L. innocua was observed for the selected field intensities, with the greatest reduction being 2 1/2 log cycles (U). The exposure of L. innocua to nisin after PEF had an additive effect on the inactivation of the microorganism as that exhibited by the PEF alone. As the electric field, number of pulses and nisin concentration increased, synergism was observed in the inactivation of L. innocua as a result of exposure to nisin after PEF. The reduction of L. innocua accomplished by exposure to 10 IU nisin/ml after 32 pulsed electric fields was 2, 2.7, and 3.4 U for an electric field intensity of 30, 40, and 50 kV/cm, respectively. Population of L. innocua subjected to 100 IU nisin/ml after PEF was 2.8-3.8 U for the selected electric field intensities and 32 pulses. The designed model for the inactivation of L. innocua as a result of the PEF followed by exposure to nisin proved to be accurate in the prediction of the inactivation of L. innocua in skim milk containing 1.2 or 37 IU nisin/ml. Inactivation of L. innocua in skim milk containing 37 IU nisin/ml resulted in a decrease in population of 3.7 U.

Effectiveness of solar disinfection using batch reactors with non-imaging aluminium reflectors under real conditions: Natural well-water and solar light.

Science.gov (United States)

Navntoft, C; Ubomba-Jaswa, E; McGuigan, K G; Fernández-Ibáñez, P

2008-12-11

Inactivation kinetics are reported for suspensions of Escherichia coli in well-water using compound parabolic collector (CPC) mirrors to enhance the efficiency of solar disinfection (SODIS) for batch reactors under real, solar radiation (cloudy and cloudless) conditions. On clear days, the system with CPC reflectors achieved complete inactivation (more than 5-log unit reduction in bacterial population to below the detection limit of 4CFU/mL) one hour sooner than the system fitted with no CPC. On cloudy days, only systems fitted with CPCs achieved complete inactivation. Degradation of the mirrors under field conditions was also evaluated. The reflectivity of CPC systems that had been in use outdoors for at least 3 years deteriorated in a non-homogeneous fashion. Reflectivity values for these older systems were found to vary between 27% and 72% compared to uniform values of 87% for new CPC systems. The use of CPC has been proven to be a good technological enhancement to inactivate bacteria under real conditions in clear and cloudy days. A comparison between enhancing optics and thermal effect is also discussed.

Glucocorticoid receptor gene inactivation in dopamine-innervated areas selectively decreases behavioral responses to amphetamine

Science.gov (United States)

Parnaudeau, Sébastien; Dongelmans, Marie-louise; Turiault, Marc; Ambroggi, Frédéric; Delbes, Anne-Sophie; Cansell, Céline; Luquet, Serge; Piazza, Pier-Vincenzo; Tronche, François; Barik, Jacques

2014-01-01

The meso-cortico-limbic system, via dopamine release, encodes the rewarding and reinforcing properties of natural rewards. It is also activated in response to abused substances and is believed to support drug-related behaviors. Dysfunctions of this system lead to several psychiatric conditions including feeding disorders and drug addiction. These disorders are also largely influenced by environmental factors and in particular stress exposure. Stressors activate the corticotrope axis ultimately leading to glucocorticoid hormone (GCs) release. GCs bind the glucocorticoid receptor (GR) a transcription factor ubiquitously expressed including within the meso-cortico-limbic tract. While GR within dopamine-innervated areas drives cocaine's behavioral responses, its implication in responses to other psychostimulants such as amphetamine has never been clearly established. Moreover, while extensive work has been made to uncover the role of this receptor in addicted behaviors, its contribution to the rewarding and reinforcing properties of food has yet to be investigated. Using mouse models carrying GR gene inactivation in either dopamine neurons or in dopamine-innervated areas, we found that GR in dopamine responsive neurons is essential to properly build amphetamine-induced conditioned place preference and locomotor sensitization. c-Fos quantification in the nucleus accumbens further confirmed defective neuronal activation following amphetamine injection. These diminished neuronal and behavioral responses to amphetamine may involve alterations in glutamate transmission as suggested by the decreased MK801-elicited hyperlocomotion and by the hyporeactivity to glutamate of a subpopulation of medium spiny neurons. In contrast, GR inactivation did not affect rewarding and reinforcing properties of food suggesting that responding for natural reward under basal conditions is preserved in these mice. PMID:24574986

Glucocorticoid receptor gene inactivation in dopamine-innervated areas selectively decreases behavioral responses to amphetamine

Directory of Open Access Journals (Sweden)

Sebastien eParnaudeau

2014-02-01

Full Text Available The meso-cortico-limbic system, via dopamine release, encodes the rewarding and reinforcing properties of natural rewards. It is also activated in response to abused substances and is believed to support drug-related behaviors. Dysfunctions of this system lead to several psychiatric conditions including feeding disorders and drug addiction. These disorders are also largely influenced by environmental factors and in particular stress exposure. Stressors activate the corticotrope axis ultimately leading to glucocorticoid hormone (GCs release. GCs bind the glucocorticoid receptor (GR a transcription factor ubiquitously expressed including within the meso-cortico-limbic tract. While the GR within dopamine-innervated areas drives cocaine’s behavioral responses, its implication in responses to other psychostimulants such as amphetamine has never been clearly established. Moreover, while extensive work has been made to uncover the role of this receptor in addicted behaviors, its contribution to the rewarding and reinforcing properties of food has yet to be investigated. Using mouse models carrying GR gene inactivation in either dopamine neurons or in dopamine-innervated areas, we found that GR in dopamine responsive neurones is essential to properly build amphetamine-induced conditioned place preference and locomotor sensitization. c-Fos quantification in the nucleus accumbens further confirmed defective neuronal activation following amphetamine injection. These diminished neuronal and behavioral responses to amphetamine may involve alterations in glutamate transmission as suggested by the decreased MK801-elicited hyperlocomotion and by the hyporeactivity to glutamate of a subpopulation of medium spiny neurons. In contrast, GR inactivation did not affect rewarding and reinforcing properties of food suggesting that responding for natural reward under basal conditions is preserved in these mice.

Heat inactivation kinetics of Hypocrea orientalis β-glucosidase with enhanced thermal stability by glucose.

Science.gov (United States)

Xu, Xin-Qi; Shi, Yan; Wu, Xiao-Bing; Zhan, Xi-Lan; Zhou, Han-Tao; Chen, Qing-Xi

2015-11-01

Thermal inactivation kinetics of Hypocrea orientalis β-glucosidase and effect of glucose on thermostability of the enzyme have been determined in this paper. Kinetic studies showed that the thermal inactivation was irreversible and first-order reaction. The microscopic rate constants for inactivation of free enzyme and substrate-enzyme complex were both determined, which suggested that substrates can protect β-glucosidase against thermal deactivation effectively. On the other hand, glucose was found to protect β-glucosidase from heat inactivation to remain almost whole activity below 70°C at 20mM concentration, whereas the apparent inactivation rate of BG decreased to be 0.3×10(-3)s(-1) in the presence of 5mM glucose, smaller than that of sugar-free enzyme (1.91×10(-3)s(-1)). The intrinsic fluorescence spectra results showed that glucose also had stabilizing effect on the conformation of BG against thermal denaturation. Docking simulation depicted the interaction mode between glucose and active residues of the enzyme to produce stabilizing effect. Copyright © 2015 Elsevier B.V. All rights reserved.

Elective Inactivation of Total Artificial Heart Technology in Non-Futile Situations: Inpatients, Outpatients and Research Participants

Science.gov (United States)

Bramstedt, Katrina A.

2004-01-01

Total artificial heart technology as a potential clinical therapy raises the issue of elective device inactivation in both futile and non-futile situations. This article explores elective device inactivation in non-futile situations. In reply to such requests for inactivation, the medical team should reflect on the individual's decision-making…

Microwave-Irradiation-Assisted HVAC Filtration for Inactivation of Viral Aerosols (Postprint)

Science.gov (United States)

2012-02-01

Baggiani, A. and Senesi, S. (2004). Effect of Microwave Radiation on Bacillus subtilis Spores . J. Appl. Microbiol. 97: 1220–1227. Damit, B., Lee, C.N...AFRL-RX-TY-TP-2012-0020 MICROWAVE-IRRADIATION-ASSISTED HVAC FILTRATION FOR INACTIVATION OF VIRAL AEROSOLS POSTPRINT Myung-Heui Woo and...12-APR-2011 -- 11-DEC-2011 Microwave Irradiation-Assisted HVAC Filtration for Inactivation of Viral Aerosols (POSTPRINT) FA8650-06-C-5913 0602102F

Thermal Inactivation of avian influenza virus in poultry litter as a method to decontaminate poultry houses.

Science.gov (United States)

Stephens, Christopher B; Spackman, Erica

2017-09-15

Removal of contaminated material from a poultry house during recovery from an avian influenza virus (AIV) outbreak is costly and labor intensive. Because AIV is not environmentally stable, heating poultry houses may provide an alternative disinfection method. The objective was to determine the time necessary to inactivate AIV in poultry litter at temperatures achievable in a poultry house. Low pathogenic (LP) AIV inactivation was evaluated between 10.0°-48.9°C, at ∼5.5°C intervals and highly pathogenic (HP) AIV inactivation was evaluated between 10.0°-43.3°C, at ∼11°C intervals. Samples were collected at numerous time points for each temperature. Virus isolation in embryonating chicken eggs was conducted to determine if viable virus was present. Each sample was also tested by real-time RT-PCR. Low pathogenicity AIV was inactivated at 1day at 26.7°C or above. At 10.0, 15.6 and 21.1°C, inactivation times increased to 2-5days. Highly pathogenic AIV followed a similar trend; the virus was inactivated after 1day at 43.3°C and 32.2°C, and required 2 and 5days for inactivation at 21.1°C and 10.0°C respectively. While low pathogenicity AIV appeared to be inactivated at a lower temperature than high pathogenicity AIV, this was not due to any difference in the strains, but due to fewer temperature points being evaluated for high pathogenicity. Endpoints for detection by real-time RT-PCR were not found even weeks after the virus was inactivated. This provides a guideline for the time required, at specific temperatures to inactivate AIV in poultry litter and likely on surfaces within the house. Heat treatment will provide an added level of safety to personnel and against further spread by eliminating infectious virus prior to cleaning a house. Published by Elsevier B.V.

Effect of various conditions on inactivation of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in fresh-cut lettuce using ultraviolet radiation.

Science.gov (United States)

Kim, Yoon-Hee; Jeong, Seul-Gi; Back, Kyeong-Hwan; Park, Ki-Hwan; Chung, Myung-Sub; Kang, Dong-Hyun

2013-09-16

The effect of various conditions on inactivation of foodborne pathogens and quality of fresh-cut lettuce during ultraviolet (254 nm, UVC) radiation was investigated. Lettuce was inoculated with a cocktail of Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes and treated at different temperatures (4 and 25 °C), distances between sample and lamp (10 and 50 cm), type of exposure (illuminated from one or two sides), UV intensities (1.36 to 6.80 mW/cm²), and exposure times (0.5 to 10 min), sequentially. UV treatment at 25 °C for 1 min achieved 1.45-, 1.35-, and 2.12-log reductions in surface-inoculated E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, whereas the reduction of these pathogens at 4 °C was 0.31, 0.57, and 1.16 log, respectively. UV radiation was most effective when distance from UV lamp to the sample was minimal (10 cm) and radiation area was maximal (two-sided exposure). All UV intensities significantly (P0.05) different from those of nontreated samples up to 5 min exposure. However, these qualities significantly (Pradiation under optimized conditions could reduce foodborne pathogens without adversely affecting color quality properties of fresh-cut lettuce. © 2013 Elsevier B.V. All rights reserved.

Pathogens Inactivated by Low-Energy-Electron Irradiation Maintain Antigenic Properties and Induce Protective Immune Responses

Science.gov (United States)

Fertey, Jasmin; Bayer, Lea; Grunwald, Thomas; Pohl, Alexandra; Beckmann, Jana; Gotzmann, Gaby; Casado, Javier Portillo; Schönfelder, Jessy; Rögner, Frank-Holm; Wetzel, Christiane; Thoma, Martin; Bailer, Susanne M.; Hiller, Ekkehard; Rupp, Steffen; Ulbert, Sebastian

2016-01-01

Inactivated vaccines are commonly produced by incubating pathogens with chemicals such as formaldehyde or β-propiolactone. This is a time-consuming process, the inactivation efficiency displays high variability and extensive downstream procedures are often required. Moreover, application of chemicals alters the antigenic components of the viruses or bacteria, resulting in reduced antibody specificity and therefore stimulation of a less effective immune response. An alternative method for inactivation of pathogens is ionizing radiation. It acts very fast and predominantly damages nucleic acids, conserving most of the antigenic structures. However, currently used irradiation technologies (mostly gamma-rays and high energy electrons) require large and complex shielding constructions to protect the environment from radioactivity or X-rays generated during the process. This excludes them from direct integration into biological production facilities. Here, low-energy electron irradiation (LEEI) is presented as an alternative inactivation method for pathogens in liquid solutions. LEEI can be used in normal laboratories, including good manufacturing practice (GMP)- or high biosafety level (BSL)-environments, as only minor shielding is necessary. We show that LEEI efficiently inactivates different viruses (influenza A (H3N8), porcine reproductive and respiratory syndrome virus (PRRSV), equine herpesvirus 1 (EHV-1)) and bacteria (Escherichia coli) and maintains their antigenicity. Moreover, LEEI-inactivated influenza A viruses elicit protective immune responses in animals, as analyzed by virus neutralization assays and viral load determination upon challenge. These results have implications for novel ways of developing and manufacturing inactivated vaccines with improved efficacy. PMID:27886076

Stress-induced changes in the expression of the clock protein PERIOD1 in the rat limbic forebrain and hypothalamus: role of stress type, time of day, and predictability.

Directory of Open Access Journals (Sweden)

Sherin Al-Safadi

Full Text Available Stressful events can disrupt circadian rhythms in mammals but mechanisms underlying this disruption remain largely unknown. One hypothesis is that stress alters circadian protein expression in the forebrain, leading to functional dysregulation of the brain circadian network and consequent disruption of circadian physiological and behavioral rhythms. Here we characterized the effects of several different stressors on the expression of the core clock protein, PER1 and the activity marker, FOS in select forebrain and hypothalamic nuclei in rats. We found that acute exposure to processive stressors, restraint and forced swim, elevated PER1 and FOS expression in the paraventricular and dorsomedial hypothalamic nuclei and piriform cortex but suppressed PER1 and FOS levels exclusively in the central nucleus of the amygdala (CEAl and oval nucleus of the bed nucleus of the stria terminalis (BNSTov. Conversely, systemic stressors, interleukin-1β and 2-Deoxy-D-glucose, increased PER1 and FOS levels in all regions studied, including the CEAl and BNSTov. PER1 levels in the suprachiasmatic nucleus (SCN, the master pacemaker, were unaffected by any of the stress manipulations. The effect of stress on PER1 and FOS was modulated by time of day and, in the case of daily restraint, by predictability. These results demonstrate that the expression of PER1 in the forebrain is modulated by stress, consistent with the hypothesis that PER1 serves as a link between stress and the brain circadian network. Furthermore, the results show that the mechanisms that control PER1 and FOS expression in CEAl and BNSTov are uniquely sensitive to differences in the type of stressor. Finally, the finding that the effect of stress on PER1 parallels its effect on FOS supports the idea that Per1 functions as an immediate-early gene. Our observations point to a novel role for PER1 as a key player in the interface between stress and circadian rhythms.

Pharmacology of the Nav1.1 domain IV voltage sensor reveals coupling between inactivation gating processes.

Science.gov (United States)

Osteen, Jeremiah D; Sampson, Kevin; Iyer, Vivek; Julius, David; Bosmans, Frank

2017-06-27

The Na v 1.1 voltage-gated sodium channel is a critical contributor to excitability in the brain, where pathological loss of function leads to such disorders as epilepsy, Alzheimer's disease, and autism. This voltage-gated sodium (Na v ) channel subtype also plays an important role in mechanical pain signaling by primary afferent somatosensory neurons. Therefore, pharmacologic modulation of Na v 1.1 represents a potential strategy for treating excitability disorders of the brain and periphery. Inactivation is a complex aspect of Na v channel gating and consists of fast and slow components, each of which may involve a contribution from one or more voltage-sensing domains. Here, we exploit the Hm1a spider toxin, a Na v 1.1-selective modulator, to better understand the relationship between these temporally distinct modes of inactivation and ask whether they can be distinguished pharmacologically. We show that Hm1a inhibits the gating movement of the domain IV voltage sensor (VSDIV), hindering both fast and slow inactivation and leading to an increase in Na v 1.1 availability during high-frequency stimulation. In contrast, ICA-121431, a small-molecule Na v 1.1 inhibitor, accelerates a subsequent VSDIV gating transition to accelerate entry into the slow inactivated state, resulting in use-dependent block. Further evidence for functional coupling between fast and slow inactivation is provided by a Na v 1.1 mutant in which fast inactivation removal has complex effects on slow inactivation. Taken together, our data substantiate the key role of VSDIV in Na v channel fast and slow inactivation and demonstrate that these gating processes are sequential and coupled through VSDIV. These findings provide insight into a pharmacophore on VSDIV through which modulation of inactivation gating can inhibit or facilitate Na v 1.1 function.

Pulsed electric field inactivation in a microreactor

NARCIS (Netherlands)

Fox, M.B.

2006-01-01

Pulsed electric fields (PEF) is a novel, non-thermal pasteurization method which uses short, high electric field pulses to inactivate microorganisms. The advantage of a pasteurization method like PEF compared to regular heat pasteurization is that the taste, flavour, texture and nutritional value

Complicated biallelic inactivation of Pten in radiation-induced mouse thymic lymphomas

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, Yu [Department of Biology, Graduate School of Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Takabatake, Takashi; Kakinuma, Shizuko; Amasaki, Yoshiko; Nishimura, Mayumi; Imaoka, Tatsuhiko; Yamauchi, Kazumi; Shang, Yi [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Miyoshi-Imamura, Tomoko [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Genetic Counseling Program, Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1 Otsuka, Bunkyou-ku, Tokyo 112-8610 (Japan); Nogawa, Hiroyuki [Department of Biology, Graduate School of Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Kobayashi, Yoshiro [Department of Biomolecular Science, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510 (Japan); Shimada, Yoshiya, E-mail: y_shimad@nirsgo.jp [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan)

2010-04-01

Inactivation of the phosphatase and tensin homolog gene (Pten) occurs via multiple tissue-dependent mechanisms including epigenetic silencing, point mutations, insertions, and deletions. Although frequent loss of heterozygosity around the Pten locus and plausible involvement of epigenetic silencing have been reported in radiation-induced thymic lymphomas, the proportion of lymphomas with inactivated Pten and the spectrum of causal aberrations have not been extensively characterized. Here, we assessed the mode of Pten inactivation by comprehensive analysis of the expression and alteration of Pten in 23 radiation-induced thymic lymphomas developed in B6C3F1 mice. We found no evidence for methylation-associated silencing of Pten; rather, complex structural abnormalities comprised of missense and nonsense mutations, 1- and 3-bp insertions, and focal deletions were identified in 8 of 23 lymphomas (35%). Sequencing of deletion breakpoints suggested that aberrant V(D)J recombination and microhomology-mediated rearrangement were responsible for the focal deletions. Seven of the 8 lymphomas had biallelic alterations, and 4 of them did not express Pten protein. These Pten aberrations coincided with downstream Akt phosphorylation. In conclusion, we demonstrate that Pten inactivation is frequently biallelic and is caused by a variety of structural abnormalities (rather than by epigenetic silencing) and is involved in radiation-induced lymphomagenesis.

Functional size analysis of bioactive materials by radiation inactivation

International Nuclear Information System (INIS)

Kume, Tamikazu

1994-01-01

When the research on various proteins including enzymes is carried out, first molecular weight is measured. The physical chemical methods used for measuring molecular weight cannot measure it in the state of actually acting in living bodies. Radiation inactivation method is the unique method which can measure the molecular weight of the active substances in living bodies. Paying attention to this point, recently it is attempted to measure the activity unit of enzymes, receptors and others, and to apply to the elucidation of their functions. In this report, the concept of the method of measuring molecular size based on radiation inactivation, the detailed experimental method and the points to which attention must be paid are described. Also its application to the elucidation of living body functions according to the example of the studies by the author is reported. The concept of the measurement of molecular weight by radiation inactivation is based on target theory. The preparation of samples, the effect of oxygen, radiation sources, dosimetry, irradiation temperature, internal standard process and so on are reported. The trend of the research is shown. (K.I.)

Viral inactivation in hemotherapy: systematic review on inactivators with action on nucleic acids

Directory of Open Access Journals (Sweden)

Patricia Marial Sobral

2012-01-01

Full Text Available The aim of this study was to conduct a systematic review on the photoinactivators used in hemotherapy, with action on viral genomes. The SciELO, Science Direct, PubMed and Lilacs databases were searched for articles. The inclusion criterion was that these should be articles on inactivators with action on genetic material that had been published between 2000 and 2010. The key words used in identifying such articles were "hemovigilance", "viral inactivation", "photodynamics", "chemoprevention" and "transfusion safety". Twenty-four articles on viral photoinactivation were found with the main photoinactivators covered being: methylene blue, amotosalen HCl, S-303 frangible anchor linker effector (FRALE, riboflavin and inactin. The results showed that methylene blue has currently been studied least, because it diminishes coagulation factors and fibrinogen. Riboflavin has been studied most because it is a photoinactivator of endogenous origin and has few collateral effects. Amotosalen HCl is effective for platelets and is also used on plasma, but may cause changes both to plasma and to platelets, although these are not significant for hemostasis. S-303 FRALE may lead to neoantigens in erythrocytes and is less indicated for red-cell treatment; in such cases, PEN 110 is recommended. Thus, none of the methods for pathogen reduction is effective for all classes of agents and for all blood components, but despite the high cost, these photoinactivators may diminish the risk of blood-transmitted diseases.

Deletion of an X-inactivation boundary disrupts adjacent gene silencing.

Directory of Open Access Journals (Sweden)

Lindsay M Horvath

2013-11-01

Full Text Available In mammalian females, genes on one X are largely silenced by X-chromosome inactivation (XCI, although some "escape" XCI and are expressed from both Xs. Escapees can closely juxtapose X-inactivated genes and provide a tractable model for assessing boundary function at epigenetically regulated loci. To delimit sequences at an XCI boundary, we examined female mouse embryonic stem cells carrying X-linked BAC transgenes derived from an endogenous escape locus. Previously we determined that large BACs carrying escapee Kdm5c and flanking X-inactivated transcripts are properly regulated. Here we identify two lines with truncated BACs that partially and completely delete the distal Kdm5c XCI boundary. This boundary is not required for escape, since despite integrating into regions that are normally X inactivated, transgenic Kdm5c escapes XCI, as determined by RNA FISH and by structurally adopting an active conformation that facilitates long-range preferential association with other escapees. Yet, XCI regulation is disrupted in the transgene fully lacking the distal boundary; integration site genes up to 350 kb downstream of the transgene now inappropriately escape XCI. Altogether, these results reveal two genetically separable XCI regulatory activities at Kdm5c. XCI escape is driven by a dominant element(s retained in the shortest transgene that therefore lies within or upstream of the Kdm5c locus. Additionally, the distal XCI boundary normally plays an essential role in preventing nearby genes from escaping XCI.

Inactivation of Bacillus atrophaeus and of Aspergillus niger using beams of argon ions, of oxygen molecules and of oxygen atoms

Energy Technology Data Exchange (ETDEWEB)

Raballand, V; Benedikt, J; Keudell, A von [Research Group Reactive Plasmas, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Wunderlich, J [Fraunhofer Institut for Process Engineering and Packaging, Giggenhauser Strasse 35, 85354 Freising (Germany)], E-mail: Achim.vonKeudell@rub.de

2008-06-07

The inactivation of spores of Bacillus atrophaeus and of Aspergillus niger using beams of argon ions, of oxygen molecules and of oxygen atoms is studied. Thereby, the conditions occurring in oxygen containing low pressure plasmas are mimicked and fundamental inactivation mechanisms can be revealed. It is shown that the impact of O atoms has no effect on the viability of the spores and that no etching of the spore coat occurs up to an O atom fluence of 3.5 x 10{sup 19} cm{sup -2}. The impact of argon ions with an energy of 200 eV does not cause significant erosion for fluences up to 1.15 x 10{sup 18} cm{sup -2}. However, the combined impact of argon ions and oxygen molecules or atoms causes significant etching of the spores and significant inactivation. This is explained by the process of chemical sputtering, where an ion-induced defect at the surface of the spore reacts with either the incident bi-radical O{sub 2} or with an incident O atom. This leads to the formation of CO, CO{sub 2} and H{sub 2}O and thus to erosion.

Enteric virus removal inactivation by coal-based media

Energy Technology Data Exchange (ETDEWEB)

Gupta, A.; Chaudhuri, M. [Indian Institute of Technology, Kanpur (India). Dept. of Civil Engineering

1995-02-01

Four coal-based media, viz. alum-pretreated or ferric hydroxide-impregnated Giridih bituminous coal and lignite (alum-GBC, Fe-GBC; alum-lignite and Fe-Lignite) were laboratory tested to assess their potential in removing/inactivating enteric viruses in water. Batch-sorption screening tests, employing a poliovirus-spiked canal water, indicated high poliovirus sorption by Fe-GBC and alum-GBC in a short contact time of 5 min. Based on the results of further batch-sorption tests, using silver incorporated media (alum/Ag-GBC, alum-GBC-Ag and Fe-GBC-Ag), as well as aesthetic water quality consideration and previous findings on removal of coliforms and turbidity, alum/Ag-GBC, alum-GBC and alum-GBC-AG were included in downflow column studies employing poliovirus-spiked canal water. All three media showed potential in removing/inactivating enteric viruses. In a separate column study employing a joint challenge of poliovirus and rotavirus, alum/Ag-GBC removed 59.3-86.5% of the viruses along with more than 99% reduction in indigenous heterotrophic bacteria. Alum/silver-pretreated bituminous coal medium appears promising for use in household water filters in rural areas of the developing world. However, improved medium preparation to further enhance its efficiency is needed; also, its efficacy in removing/inactivating indigenous enteric bacteria, viruses and protozoa has to be ensured and practicalities or economics of application need to be considered.

High Pressure Inactivation of HAV within Mussels

Science.gov (United States)

The potential of hepatitis A virus (HAV) to be inactivated within Mediterranean mussels (Mytilus galloprovincialis) and blue mussels (Mytilus edulis) by high pressure processing was evaluated. HAV was bioaccumulated within mussels to approximately 6-log10 PFU by exposure of mussels to HAV-contamina...

Sexually localized expression of pseudo-self compatibility (PSC) in Petunia X hybrida Hort : 2. Stylar inactivation.

Science.gov (United States)

Dana, M N; Ascher, P D

1986-01-01

A previously identified S-linked stylar-inactivation PSC factor (Flaschenriem and Ascher 1979b) was studied for its location relative to S. Plants exhibiting complete stylar-inactivation PSC were those with higher multigenic PSC background level than plants with only S-linked partial stylar-inactivation PSC. A pollen-mediated pseudo-self compatibility (PMPSC) adjustment factor was offered as a device to focus on stylar-inactivation PSC by removing some male origin, multigenic PSC. The stylar inactivation factor was not tightly linked to S but affected expression of only the allele to which it was linked. A three part interacting association of genetic material governing self incompatibility (SI) is proposed. The parts of S are the SI identity gene, S-specific PSC genes and, finally, PSC genes which are not S-specific in action. The complete association is termed the SI-complex.

Trading direct for indirect defense? Phytochrome B inactivation in tomato attenuates direct anti-herbivore defenses whilst enhancing volatile-mediated attraction of predators

NARCIS (Netherlands)

Cortés, Leandro E.; Weldegergis, Berhane T.; Boccalandro, Hernán E.; Dicke, Marcel; Ballaré, Carlos L.

2016-01-01

Under conditions of competition for light, which lead to the inactivation of the photoreceptor phytochrome B (phyB), the growth of shade-intolerant plants is promoted and the accumulation of direct anti-herbivore defenses is down-regulated. Little is known about the effects of phyB on emissions

Propagated but Topologically Distributed Forebrain Neurons Expressing Alpha-Synuclein in Aged Macaques.