| 1. |
- Covacu, Ruxandra, et al.
(author)
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Nitric oxide exposure diverts neural stem cell fate from neurogenesis towards astrogliogenesis
- 2006
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In: Stem Cells. - : Oxford University Press (OUP). - 1066-5099 .- 1549-4918. ; 178, s. 268-268
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Journal article (other academic/artistic)abstract
- Regeneration of cells in the central nervous system is a process that might be affected during neurological disease and trauma. Because nitric oxide (NO) and its derivatives are powerful mediators in the inflammatory cascade, we have investigated the effects of pathophysiological concentrations of NO on neurogenesis, gliogenesis, and the expression of proneural genes in primary adult neural stem cell cultures. After exposure to NO, neurogenesis was downregulated, and this corresponded to decreased expression of the proneural gene neurogenin-2 and beta-III-tubulin. The decreased ability to generate neurons was also found to be transmitted to the progeny of the cells. NO exposure was instead beneficial for astroglial differentiation, which was confirmed by increased activation of the Janus tyrosine kinase/signal transducer and activator of transcription transduction pathway. Our findings reveal a new role for NO during neuroinflammatory conditions, whereby its proastroglial fate-determining effect on neural stem cells might directly influence the neuroregenerative process.
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| 2. |
- Danilov, Alexandre, et al.
(author)
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Neurogenesis in the adult spinal cord in an experimental model of multiple sclerosis
- 2006
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In: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 23:2, s. 394-400
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Journal article (peer-reviewed)abstract
- Multiple sclerosis is an inflammatory disease of the central nervous system characterized by inflammation, demyelination, axonal degeneration and accumulation of neurological disability. Previously, we demonstrated that stem cells constitute a possible endogenous source for remyelination. We now addressed the question of whether neurogenesis can occur in neuroinflammatory lesions. We demonstrated that, in experimental autoimmune encephalomyelitis, induced in rats 1,1'-dioctadecyl-6,6'-di(4sulphopentyl)-3,3,3',3'tetramethylindocarbocyani n(DiI)-labelled ependymal cells not only proliferated but descendants migrated to the area of neuroinflammation and differentiated into cells expressing the neuronal markers beta-III-tubulin and NeuN. Furthermore, these cells were immunoreactive for bromodeoxyuridine and PCNA, markers for cells undergoing cell proliferation. Using the whole-cell patch-clamp technique on freshly isolated 1, DiI-labelled cells from spinal cord lesions we demonstrated the ability of these cells to fire overshooting action potentials similar to those of immature neurones. We thus provide the first evidence for the initiation of neurogenesis in neuroinflammatory lesions in the adult spinal cord.
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| 3. |
- Kvernebo, Anne Kari, et al.
(author)
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Quantification of ocular surface microcirculation by computer assisted video microscopy and diffuse reflectance spectroscopy
- 2020
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In: Experimental Eye Research. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0014-4835 .- 1096-0007. ; 201
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Journal article (peer-reviewed)abstract
- In piglets we tested the applicability of digital video microscopy and diffuse reflectance spectroscopy for non-invasive assessments of limbal and bulbar conjunctival microcirculation. A priori we postulated that the metabolic rate is higher in limbal as compared to bulbar conjunctiva, and that this difference is reflected in micro vascular structure or function between the two locations. Two study sites, Oslo University Hospital (OUH), Norway and Cleveland Clinic (CC), USA, used the same video microscopy and spectroscopy techniques to record limbal and bulbar microcirculation in sleeping piglets. Recordings were analyzed with custom-made software to quantify functional capillary density, capillary flow velocity and microvascular oxygen saturation in measuring volumes of approximately 0.1 mm(3). The functional capillary density was higher in limbus than in bulbar conjunctiva at both study sites (OUH: 18.1 +/- 2.9 versus 12.2 +/- 2.9 crossings per mm line, p < 0.01; CC: 11.3 +/- 3.0 versus 7.1 +/- 2.8 crossings per mm line, p < 0.01). Median categorial capillary blood flow velocity was higher in bulbar as compared with limbal recordings (CC: 3 (1-3) versus 1 (0-3), p < 0.01). Conjunctival microvascular oxygen saturation was 88 +/- 5.9% in OUH versus 94 +/- 7.5% in CC piglets. Non-invasive digital video microscopy and diffuse reflectance spectroscopy can be used to obtain data from conjunctival microcirculation in piglets. Limbal conjunctival microcirculation has a larger capacity for oxygen delivery as compared with bulbar conjunctiva.
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| 4. |
- Landsend, Erlend C. S., et al.
(author)
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Characteristics and Utility of Fundus Autofluorescence in Congenital Aniridia Using Scanning Laser Ophthalmoscopy
- 2019
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In: Investigative Ophthalmology and Visual Science. - : ASSOC RESEARCH VISION OPHTHALMOLOGY INC. - 0146-0404 .- 1552-5783. ; 60:13, s. 4120-4128
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Journal article (peer-reviewed)abstract
- PURPOSE. To investigate fundus autofluorescence (FAF) and other fundus manifestations in congenital aniridia. METHODS. Fourteen patients with congenital aniridia and 14 age- and sex-matched healthy controls were examined. FAF images were obtained with an ultra-widefield scanning laser ophthalmoscope. FAF intensity was quantified in the macular fovea and in a macular ring surrounding fovea and related to an internal reference within each image. All aniridia patients underwent an ophthalmologic examination, including optical coherence tomography and slitlamp biomicroscopy. RESULTS. Mean age was 28.4 +/- 15.0 years in both the aniridia and control groups. Fovea could be defined by subjective assessment of FAF images in three aniridia patients (21.4%) and in all controls (P = 0.001). Mean ratio between FAF intensity in the macular ring and fovea was 1.01 +/- 0.15 in aniridia versus 1.18 +/- 0.09 in controls (P = 0.034). In aniridia, presence of foveal hypoplasia evaluated by biomicroscopy correlated with lack of foveal appearance by subjective analyses of FAF images (P = 0.031) and observation of nystagmus (P = 0.009). CONCLUSIONS. Aniridia patients present a lower ratio between FAF intensity in the peripheral and central macula than do healthy individuals. Both subjective and objective analyses of FAF images are useful tools in evaluation of foveal hypoplasia in aniridia.
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| 5. |
- Moe, Morten K., et al.
(author)
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The structure of the fire fighting foam surfactant Forafac (R) 1157 and its biological and photolytic transformation products
- 2012
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In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 89:7, s. 869-875
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Journal article (peer-reviewed)abstract
- For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac (R) 1157, developed by the DuPont company. The major component of Forafac (R) 1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time. In the present work, the structure of the 6:2 FTAB was elucidated by H-1, C-13 and F-19 nuclear magnetic resonance Spectroscopy and high-resolution mass spectrometry. Moreover, its major metabolites from blue mussel (Mytilus edulis) and turbot (Scophthalmus maximus) and its photolytic transformation products were identified. Contrary to what has earlier been observed for PFOS, the 6:2 FTAB was extensively metabolized by blue mussel and turbot exposed to Forafac (R) 1157. The major metabolite was a deacetylated betaine species, from which mono- and di-demethylated metabolites also were formed. Another abundant metabolite was the 6:2 fluorotelomer sulfonamide. In another experiment, Forafac (R) 1157 was subjected to UV-light induced photolysis. The experimental conditions aimed to simulate Arctic conditions and the deacetylated species was again the primary transformation product of 6:2 FTAB. A 6:2 fluorotelomer sulfonamide was also formed along with a non-identified transformation product. The environmental presence of most of the metabolites and transformation products was qualitatively demonstrated by analysis of soil samples taken in close proximity to an airport fire training facility.
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| 6. |
- Moe, Randi Opperman, et al.
(author)
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Anticipatory and foraging behaviors in response to palatable food rewardin chickens : Effects of dopamine D2 receptor blockade and domestication
- 2014
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In: Physiology and Behavior. - : Elsevier. - 0031-9384 .- 1873-507X. ; 133, s. 170-177
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Journal article (peer-reviewed)abstract
- Behaviors associatedwith anticipation and search for palatable foodmay provide information about dopaminergicreward processes and positivemotivational affect in animals. The overall aimwas to investigate the involvement ofdopamine signaling in the regulation of cue-induced anticipation and search for palatable food reward in chicken,and whether domestication has affected expression of reward-related behaviors. The specific aimswere to describeeffects of mealworms (palatable food for hens) and haloperidol (a dopamine D2 antagonist) onforaging behaviors and cue-induced anticipatory behaviors in Red Junglefowl (RJF; the wild ancestor of modernlaying hens) and awhite layer hybrid (LSL). RJF (n=26) and LSL (n=20)were initially trained on a conditioningschedule to anticipate mealworms (unconditioned stimulus; US) 25 s after exposure to a red light (conditionedstimulus; CS). For the experiment, hens received haloperidol or saline injections 30 min before exposure to oneCS + US combination. Behavior was registered 10 min before CS and 10 min after US (foraging behaviors), andduring the CS–US interval (anticipatory behaviors). Higher frequencies of CS-induced anticipatory head movements,faster approach to rewards, and higher frequency of foraging behaviors were found in LSL compared toRJF. Haloperidol suppressed CS-induced headmovements in both breeds, and the frequency of foraging behaviorsafter reward delivery. The results support a role of dopamine signaling in the regulation of reward processes inchickens, and suggest that domestication has changed the threshold for perceiving food incentives and/or forexpressing reward-related behaviors that may be indicative of positive motivational affect in hens.
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| 9. |
- Ottesen, Anett Hellebø, et al.
(author)
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Secretoneurin is a novel prognostic cardiovascular biomarker associated with cardiomyocyte calcium handling.
- 2015
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In: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097 .- 1558-3597. ; 65:4, s. 339-51
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Journal article (peer-reviewed)abstract
- BACKGROUND: Secretoneurin (SN) levels are increased in patients with heart failure (HF), but whether SN provides prognostic information and influences cardiomyocyte function is unknown.OBJECTIVES: This study sought to evaluate the merit of SN as a cardiovascular biomarker and assess effects of SN on cardiomyocyte Ca(2+) handling.METHODS: We assessed the association between circulating SN levels and mortality in 2 patient cohorts and the functional properties of SN in experimental models.RESULTS: In 143 patients hospitalized for acute HF, SN levels were closely associated with mortality (n = 66) during follow-up (median 776 days; hazard ratio [lnSN]: 4.63; 95% confidence interval: 1.93 to 11.11; p = 0.001 in multivariate analysis). SN reclassified patients to their correct risk strata on top of other predictors of mortality. In 155 patients with ventricular arrhythmia-induced cardiac arrest, SN levels were also associated with short-term mortality (n = 51; hazard ratio [lnSN]: 3.33; 95% confidence interval: 1.83 to 6.05; p < 0.001 in multivariate analysis). Perfusing hearts with SN yielded markedly increased myocardial levels and SN internalized into cardiomyocytes by endocytosis. Intracellularly, SN reduced Ca(2+)/calmodulin (CaM)-dependent protein kinase II δ (CaMKIIδ) activity via direct SN-CaM and SN-CaMKII binding and attenuated CaMKIIδ-dependent phosphorylation of the ryanodine receptor. SN also reduced sarcoplasmic reticulum Ca(2+) leak, augmented sarcoplasmic reticulum Ca(2+) content, increased the magnitude and kinetics of cardiomyocyte Ca(2+) transients and contractions, and attenuated Ca(2+) sparks and waves in HF cardiomyocytes.CONCLUSIONS: SN provided incremental prognostic information to established risk indices in acute HF and ventricular arrhythmia-induced cardiac arrest.
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