Free space techniky
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The diffusion parameters in rat cortex were studied 3-35 days following a cortical stab wound, using diffusion-weighted MR to determine the apparent diffusion coefficient of water (ADC(W)) in the tissue, and the real-time iontophoretic tetramethylammonium (TMA) method to measure the extracellular space (ECS) diffusion parameters: ECS volume fraction alpha and the ADC of TMA(+) (ADC(TMA)). Severe astrogliosis was found close to the wound, and mild astrogliosis was found in the ipsilateral but not the contralateral cortex. Chondroitin sulfate proteoglycan (CSPG) expression was increased throughout the ipsilateral cortex. In the hemisphere contralateral to the wound, alpha, ADC(TMA), and ADC(W) were not significantly different from control values. ECS volume fraction was increased only in the vicinity of the wound, in the region of cell death and severe astrogliosis, at 3 and 7 days after injury. However, both ADC(TMA) and ADC(W) were significantly decreased after lesion in the vicinity of the wound as well as in the rest of the ipsilateral hemisphere distant from the wound. Thus, both ADC(W) and ADC(TMA) decreased in regions wherein alpha did not change but CSPG increased. An increase in extracellular matrix expression may therefore impose diffusion barriers for water as well as for TMA molecules.
- MeSH
- difuze MeSH
- extracelulární prostor metabolismus MeSH
- gangliová stimulancia farmakologie MeSH
- glióza patologie MeSH
- imunohistochemie MeSH
- krysa rodu Rattus MeSH
- magnetická rezonanční spektroskopie MeSH
- magnetická rezonanční tomografie * MeSH
- mapování mozku MeSH
- modely nemocí na zvířatech MeSH
- mozková kůra patologie patofyziologie MeSH
- poranění mozku diagnóza metabolismus MeSH
- potkani Wistar MeSH
- senzitivita a specificita MeSH
- voda metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- gangliová stimulancia MeSH
- voda MeSH
- MeSH
- bránice účinky léků MeSH
- dimethylformamid metabolismus MeSH
- draslík farmakologie MeSH
- krysa rodu Rattus MeSH
- propylenglykoly metabolismus MeSH
- radionuklidy metabolismus MeSH
- svaly metabolismus MeSH
- techniky in vitro MeSH
- xylosa metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- dimethylformamid MeSH
- draslík MeSH
- propylenglykoly MeSH
- radionuklidy MeSH
- xylosa MeSH
Retinal images are essential clinical resources for the diagnosis of retinopathy and many other ocular diseases. Because of improper acquisition conditions or inherent optical aberrations in the eye, the images are often degraded with blur. In many common cases, the blur varies across the field of view. Most image deblurring algorithms assume a space-invariant blur, which fails in the presence of space-variant (SV) blur. In this work, we propose an innovative strategy for the restoration of retinal images in which we consider the blur to be both unknown and SV. We model the blur by a linear operation interpreted as a convolution with a point-spread function (PSF) that changes with the position in the image. To achieve an artifact-free restoration, we propose a framework for a robust estimation of the SV PSF based on an eye-domain knowledge strategy. The restoration method was tested on artificially and naturally degraded retinal images. The results show an important enhancement, significant enough to leverage the images' clinical use.
- MeSH
- algoritmy MeSH
- angiografie metody MeSH
- artefakty MeSH
- astigmatismus diagnóza MeSH
- diagnostické techniky oftalmologické * MeSH
- fundus oculi MeSH
- lidé MeSH
- normální rozdělení MeSH
- optika a fotonika MeSH
- počítačové zpracování obrazu MeSH
- reprodukovatelnost výsledků MeSH
- retina patologie MeSH
- retinální cévy patologie MeSH
- rozpoznávání automatizované metody MeSH
- statistické modely MeSH
- zrak MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Glutamate release, particularly in pathologic conditions, may result in cellular swelling. The authors studied the effects of glutamate, N-methyl-D-aspartate (NMDA), and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) on extracellular pH (pH(e)), extracellular potassium concentration ([K(+)](e)), and changes in extracellular space (ECS) diffusion parameters (volume fraction alpha, tortuosity lambda) resulting from cellular swelling. In the isolated spinal cord of 4-to 12-day-old rats, the application of glutamate receptor agonists induced an increase in [K(+)](e), alkaline-acid shifts, a substantial decrease in alpha, and an increase in lambda. After washout of the glutamate receptor agonists, alpha either returned to or overshot normal values, whereas lambda remained elevated. Pretreatment with 20 mmol/L Mg(++), MK801, or CNQX blocked the changes in diffusion parameters, [K(+)](e) and pH(e) evoked by NMDA or AMPA. However, the changes in diffusion parameters also were blocked in Ca(2+)-free solution, which had no effect on the [K(+)](e) increase or acid shift. The authors conclude that increased glutamate release may produce a large, sustained and [Ca(2+)](e)-dependent decrease in alpha and increase in lambda. Repetitive stimulation and pathologic states resulting in glutamate release therefore may lead to changes in ECS volume and tortuosity, affecting volume transmission and enhancing glutamate neurotoxicity and neuronal damage.
- MeSH
- 6-kyano-7-nitrochinoxalin-2,3-dion farmakologie MeSH
- agonisté excitačních aminokyselin farmakologie MeSH
- antagonisté excitačních aminokyselin farmakologie MeSH
- buněčná smrt účinky léků MeSH
- chelátory farmakologie MeSH
- difuze MeSH
- dizocilpinmaleát farmakologie MeSH
- draslík metabolismus MeSH
- edém patologie MeSH
- EGTA farmakologie MeSH
- extracelulární prostor účinky léků metabolismus MeSH
- glióza metabolismus patologie MeSH
- hořčík farmakologie MeSH
- koncentrace vodíkových iontů MeSH
- krysa rodu Rattus MeSH
- kyselina alfa-amino-3-hydroxy-5-methyl-4-isoxazolpropionová farmakologie MeSH
- kyselina glutamová farmakologie MeSH
- mícha účinky léků metabolismus patologie MeSH
- N-methylaspartát farmakologie MeSH
- potkani Wistar MeSH
- techniky in vitro MeSH
- vápník farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- 6-kyano-7-nitrochinoxalin-2,3-dion MeSH
- agonisté excitačních aminokyselin MeSH
- antagonisté excitačních aminokyselin MeSH
- chelátory MeSH
- dizocilpinmaleát MeSH
- draslík MeSH
- EGTA MeSH
- hořčík MeSH
- kyselina alfa-amino-3-hydroxy-5-methyl-4-isoxazolpropionová MeSH
- kyselina glutamová MeSH
- N-methylaspartát MeSH
- vápník MeSH
- MeSH
- aminobutyráty metabolismus MeSH
- extracelulární prostor metabolismus MeSH
- glutamáty metabolismus MeSH
- hypothalamus účinky léků MeSH
- katecholaminy farmakologie MeSH
- krysa rodu Rattus MeSH
- noradrenalin farmakologie MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aminobutyráty MeSH
- glutamáty MeSH
- katecholaminy MeSH
- noradrenalin MeSH
- MeSH
- elektrická stimulace MeSH
- extracelulární prostor metabolismus MeSH
- glutamáty metabolismus MeSH
- guanethidin farmakologie MeSH
- hydrokortison farmakologie MeSH
- katecholaminy farmakologie MeSH
- mozková kůra účinky léků fyziologie MeSH
- noradrenalin farmakologie MeSH
- techniky in vitro MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- glutamáty MeSH
- guanethidin MeSH
- hydrokortison MeSH
- katecholaminy MeSH
- noradrenalin MeSH
Changes in extracellular space (ECS) diffusion parameters in astrogliotic tissue around a unilateral cortical stab wound were determined from concentration-time profiles of tetramethylammonium (TMA(+)) using TMA(+)-selective microelectrodes. Three diffusion parameters-ECS volume fraction alpha (alpha = ECS volume/ total tissue volume), tortuosity lambda (lambda(2) = D/ADC; where D is the free and ADC is the apparent diffusion coefficient of TMA(+) in the brain), and nonspecific TMA(+)uptake k'-were determined at 3, 7, 21, and 35 days postwounding (dpw), in the hemispheres ipsilateral and contralateral to the lesion. Following diffusion experiments, tissue sections were immunostained for glial fibrillary acidic protein (GFAP) and chondroitin-sulphate proteoglycans (CSPG). In the area 300-1000 micron around the wound, alpha was increased at 3, 7, and 21 dpw by about 20% but returned to control values at 35 dpw; lambda was increased at all four intervals, reaching a maximum at 7 dpw. k' was lower than in the contralateral hemisphere at 7, 21, and 35 dpw. Measurements 1,500-2,000 micron from the wound revealed only an increase in lambda at 7 dpw. The time course of changes in ECS diffusion parameters closely correlated with increased staining for GFAP and CSPG. Our results show that astrogliosis significantly changes the diffusion properties of nervous tissue, making it less permissive. Both hypertrophied astrocytic processes and an enhanced formation of some extracellular matrix molecules could affect, through changes in the diffusion of molecules in the ECS, neuron-glia communication, "cross-talk" between synapses, extrasynaptic transmission, and regenerative processes.
- MeSH
- algoritmy MeSH
- astrocyty patologie MeSH
- bodné rány patologie MeSH
- buněčná membrána metabolismus MeSH
- časové faktory MeSH
- difuze MeSH
- extracelulární prostor metabolismus MeSH
- gangliová stimulancia farmakologie MeSH
- glióza patologie MeSH
- imunohistochemie MeSH
- kinetika MeSH
- krysa rodu Rattus MeSH
- kvartérní amoniové sloučeniny farmakologie MeSH
- mozková kůra zranění patologie MeSH
- potkani Wistar MeSH
- proteoglykany biosyntéza MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- gangliová stimulancia MeSH
- kvartérní amoniové sloučeniny MeSH
- proteoglykany MeSH
- tetramethylammonium MeSH Prohlížeč
To specify the site of action of the synthetic coumarin derivatives 7-hydroxy-3-(4'-hydroxyphenyl) coumarin (HHC) and 7-hydroxy-3-(4'-hydroxyphenyl) dihydrocoumarin (HHDC), we evaluated their effects on extra- and intracellular reactive oxygen species (ROS) formation in phorbol-myristate-13-acetate (PMA) stimulated human neutrophils. We studied also the effects of HHC and HHDC on possible molecular mechanisms which participate in the activation of NADPH oxidase, that is, on PKC activity, on phosphorylation of some PKC isoforms (α, βII, and δ), and on phosphorylation of the NADPH oxidase subunit p40(phox). Without affecting cytotoxicity, both coumarines tested were effective inhibitors/scavengers of ROS produced by neutrophils on extracellular level. HHC markedly diminished oxidant production and also, intracellularly, decreased PKC activity and partly phosphorylation of PKCα, βII. On the other hand, we did not observe any effect of coumarin derivatives on phosphorylation of PKC δ and on phosphorylation of the NADPH oxidase subunit p40(phox), which were suggested to be involved in the PMA-dependent intracellular activation process. In agreement with our previous findings, we assume that the different molecular structures of HHC and HHDC with their different physicochemical and free radical scavenging characteristics are responsible for their diverse effects on the parameters tested.
- MeSH
- adenosintrifosfát metabolismus MeSH
- aktivace neutrofilů účinky léků MeSH
- bezbuněčný systém MeSH
- buněčná smrt účinky léků MeSH
- dospělí MeSH
- extracelulární prostor účinky léků metabolismus MeSH
- fosfoproteiny metabolismus MeSH
- fosforylace účinky léků MeSH
- inhibiční koncentrace 50 MeSH
- intracelulární prostor účinky léků metabolismus MeSH
- izoenzymy metabolismus MeSH
- kinetika MeSH
- kumariny chemie farmakologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- luminiscenční měření MeSH
- mladý dospělý MeSH
- neutrofily cytologie účinky léků enzymologie MeSH
- reaktivní formy kyslíku metabolismus MeSH
- tetradekanoylforbolacetát farmakologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- adenosintrifosfát MeSH
- coumarin MeSH Prohlížeč
- fosfoproteiny MeSH
- izoenzymy MeSH
- kumariny MeSH
- neutrophil cytosol factor 40K MeSH Prohlížeč
- reaktivní formy kyslíku MeSH
- tetradekanoylforbolacetát MeSH
With the growing numbers of nanomaterials (NMs), there is a great demand for rapid and reliable ways of testing NM safety-preferably using in vitro approaches, to avoid the ethical dilemmas associated with animal research. Data are needed for developing intelligent testing strategies for risk assessment of NMs, based on grouping and read-across approaches. The adoption of high throughput screening (HTS) and high content analysis (HCA) for NM toxicity testing allows the testing of numerous materials at different concentrations and on different types of cells, reduces the effect of inter-experimental variation, and makes substantial savings in time and cost. HTS/HCA approaches facilitate the classification of key biological indicators of NM-cell interactions. Validation of in vitro HTS tests is required, taking account of relevance to in vivo results. HTS/HCA approaches are needed to assess dose- and time-dependent toxicity, allowing prediction of in vivo adverse effects. Several HTS/HCA methods are being validated and applied for NM testing in the FP7 project NANoREG, including Label-free cellular screening of NM uptake, HCA, High throughput flow cytometry, Impedance-based monitoring, Multiplex analysis of secreted products, and genotoxicity methods-namely High throughput comet assay, High throughput in vitro micronucleus assay, and γH2AX assay. There are several technical challenges with HTS/HCA for NM testing, as toxicity screening needs to be coupled with characterization of NMs in exposure medium prior to the test; possible interference of NMs with HTS/HCA techniques is another concern. Advantages and challenges of HTS/HCA approaches in NM safety are discussed. WIREs Nanomed Nanobiotechnol 2017, 9:e1413. doi: 10.1002/wnan.1413 For further resources related to this article, please visit the WIREs website.
- MeSH
- buněčné linie MeSH
- cytologické techniky MeSH
- intracelulární prostor chemie metabolismus MeSH
- lidé MeSH
- myši MeSH
- nanostruktury toxicita MeSH
- rychlé screeningové testy metody MeSH
- testy toxicity metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
The effect of Ca-ionophore A23187 on activation of rat blood platelets was investigated to elucidate the involvement of extracellular and intracellular Ca2+ ions. Platelet aggregation induced by 10 concentrations of the stimulus was studied in Ca-free medium as well as in the presence of EGTA and/or calcium. In Ca-free medium, A23187 induced platelet aggregation in a dose-dependent way; the mean effective concentration was 1.43 +/- 0.08 mumol/l. The stimulatory effect of ionophore was potentiated by addition of 0.01 and 0.1 mM calcium and inhibited when the calcium concentration was increased to 1 mmol/l. In the presence of EGTA, A23187-stimulated aggregation of isolated rat platelets was recorded only at a 10-times higher ionophore concentration and was then reduced to 30% in comparison with aggregation in Ca-free medium. The inhibitory effect of 1 mM EGTA was abolished by addition of 2 mM calcium. We suggest the participation of at least three calcium pools in the stimulation of rat platelets by A23187, i.e. the extracellular pool, the membrane-associated pool and the pool displacing calcium intracellularly.
- MeSH
- agregace trombocytů účinky léků fyziologie MeSH
- buněčná membrána metabolismus MeSH
- calcimycin aplikace a dávkování farmakologie MeSH
- EGTA farmakologie MeSH
- extracelulární prostor metabolismus MeSH
- intracelulární tekutina metabolismus MeSH
- krysa rodu Rattus MeSH
- potkani Wistar MeSH
- techniky in vitro MeSH
- vápník krev farmakologie MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- calcimycin MeSH
- EGTA MeSH
- vápník MeSH