Search results for "Llum"
showing 10 items of 570 documents
Antioxidant Potential of Extracts Obtained from Macro- (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata) and Micro-Algae (Chlorella v…
2018
Background: Natural antioxidants, which can replace synthetic ones due to their potential implications for health problems in children, have gained significant popularity. Therefore, the antioxidant potential of extracts obtained from three brown macroalgae (Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata) and two microalgae (Chlorella vulgaris and Spirulina platensis) using ultrasound-extraction as an innovative and green approach was evaluated. Methods: Algal extracts were obtained by ultrasound-assisted extraction using water/ethanol (50:50, v:v) as the extraction solvent. The different extracts were compared based on their antioxidant potential, measuring the extraction …
Color discrimination under mesopic conditions in cats and humans
1995
The ability to discriminate colors under various levels of mesopic illumination was studied in three cats using colored papers as stimuli and with a computer controlled training schedule. Discrimination based on brightness differences was prevented using a new method in which illuminant color was varied. The luminance threshold for color discrimination in cats was found to be 0.5 cd/m2, close to the cone threshold reported by others from ganglion cell recordings. The same experiment was carried out with human subjects and revealed a luminance threshold of 0.00042 cd/m2 for color discrimination.
Adaptation of neuronal cells to chronic oxidative stress is associated with altered cholesterol and sphingolipid homeostasis and lysosomal function
2009
Chronic oxidative stress has been causally linked to several neurodegenerative disorders. As sensitivity for oxidative stress greatly differs between brain regions and neuronal cell types, specific cellular mechanisms of adaptation to chronic oxidative stress should exist. Our objective was to identify molecular mechanisms of adaptation of neuronal cells after applying chronic sublethal oxidative stress. We demonstrate that cells resistant to oxidative stress exhibit altered cholesterol and sphingomyelin metabolisms. Stress-resistant cells showed reduced levels of molecules involved in cholesterol trafficking and intracellular accumulation of cholesterol, cholesterol precursors, and metabol…
Immunohistochemical analysis of KCNQ3 potassium channels in mouse brain.
2005
KCNQ-type potassium channels generate the so-called M-current regulating excitability in many neurons. Mutations in KCNQ2/KCNQ3 channels can cause benign familial neonatal convulsions (BFNC). We describe the immunohistochemical staining of adult and developing mouse brain using an antibody directed against the N-terminus of KCNQ3 channels (KCNQ3N). A widespread KCNQ3N immunoreactivity predominantly of neuropil but also of somata was detected in different regions of the adult mouse brain, in particular in the hippocampus, cortex, thalamus and cerebellum. This staining pattern appeared gradually and became more intense during development. In the pyramidal cell layer of the hippocampus, the im…
Evaluation of a murine single-blood-injection SAH model.
2014
The molecular pathways underlying the pathogenesis after subarachnoid haemorrhage (SAH) are poorly understood and continue to be a matter of debate. A valid murine SAH injection model is not yet available but would be the prerequisite for further transgenic studies assessing the mechanisms following SAH. Using the murine single injection model, we examined the effects of SAH on regional cerebral blood flow (rCBF) in the somatosensory (S1) and cerebellar cortex, neuro-behavioural and morphological integrity and changes in quantitative electrocorticographic and electrocardiographic parameters. Micro CT imaging verified successful blood delivery into the cisterna magna. An acute impairment of …
Intermittent ethanol exposure induces inflammatory brain damage and causes long-term behavioural alterations in adolescent rats
2007
Adolescent brain development seems to be important for the maturation of brain structures and behaviour. Intermittent binge ethanol drinking is common among adolescents, and this type of drinking can induce brain damage. Because we have demonstrated that chronic ethanol treatment induces inflammatory processes in the brain, we investigate whether intermittent ethanol intoxication enhances cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in adolescent rats, and whether these mediators induce brain damage and cause permanent cognitive dysfunctions. Adolescent rats were exposed to ethanol (3.0 g/kg) for two consecutive days at 48-h intervals over 14 days. Levels of COX-2, iN…
The Dual Role of the GABAA Receptor in Peripheral Inflammation and Neuroinflammation: A Study in Hyperammonemic Rats
2021
Cognitive and motor impairment in minimal hepatic encephalopathy (MHE) are mediated by neuroinflammation, which is induced by hyperammonemia and peripheral inflammation. GABAergic neurotransmission in the cerebellum is altered in rats with chronic hyperammonemia. The mechanisms by which hyperammonemia induces neuroinflammation remain unknown. We hypothesized that GABAA receptors can modulate cerebellar neuroinflammation. The GABAA antagonist bicuculline was administrated daily (i.p.) for four weeks in control and hyperammonemic rats. Its effects on peripheral inflammation and on neuroinflammation as well as glutamate and GABA neurotransmission in the cerebellum were assessed. In hyperammone…
Femoral neck’s fracture in Fahr’s Syndrome: case report
2016
Fahr's syndrome, also known as "Bilateral Striopallidodentate Calcinosis" (BSPDC) primitive, is a rare neurological disease characterized by the presence of idiopathic, bilateral, symmetrical and abnormal deposition of calcium in areas of the brain that control movements including the basal ganglia, dentate nuclei of the cerebellum, nuclei of thalamus and semi-oval center. We describe a case of a 76-year-old male patient underwent reduction and fixation of a subtrochanteric fracture with intramedullary nail. During post-operative rehabilitation therapists's patient management was difficult due to obvious extrapyramidal symptoms characterized by dysarthria, rigidity, bradykinesia, postural i…
Motor problems in children with early-treated congenital hypothyroidism: A matter of failing cerebellar motor control?
1998
This study addresses the question of whether "clumsiness" in children with early treated Congenital Hypothyroidism (CH) might be attributable to cerebellar dysfunction. CH is known to affect rapid perinatal growth of the cerebellum. If this would affect the supposed motor timing function of the cerebellum this should be especially reflected by difficulty in producing fast aiming movements. An experiment was devised in which children made sequences of fast, goal directed movements in order to examine two aspects of fast voluntary movements that are known to be affected by cerebellar injury: dysmetria and dysdiadochokinesis. Three groups of children between the ages of 9 and ii participated: …
The efficacy of photodynamic therapy in rat tongue dysplasia
2017
Background Photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) has previously shown promising results in cancerous cell destruction. The present study was conducted to evaluate the efficacy of this treatment option on oral epithelial dysplasia in Wistar rats. Furthermore, microscopic effects of systemic versus topical administration of ALA before laser illumination was assessed. Material and Methods Thirty male Wistar rats (200- 250 grams) were used in the present study. Tongue dysplasia was induced by a daily delivery of a 20 ppm solution of 4-nitroquinoline -1- oxide (4NQO) for 3 months. Then, rats were divided into 3 groups of 10 including, group 1 that was received systemic ALA…