Search results for "Animal Model"
showing 10 items of 241 documents
Tissue oxygenation in brain, muscle and fat in a rat model of sleep apnea: differential effect of obstructive apneas and intermittent hypoxia.
2011
Study Objectives: To test the hypotheses that the dynamic changes in brain oxygen partial pressure (PtO 2) in response to obstructive apneas or to intermittent hypoxia differ from those in other organs and that the changes in brain PtO 2 in response to obstructive apneas is a source of oxidative stress. Design: Prospective controlled animal study. Setting: University laboratory. Participants: 98 Sprague-Dawley rats. Interventions: Cerebral cortex, skeletal muscle, or visceral fat tissues were exposed in anesthetized animals subjected to either obstructive apneas or intermittent hypoxia (apneic and hypoxic events of 15 s each and 60 events/h) for 1 h. Measurements and Results: Arterial oxyge…
Retinal ganglion cell loss is accompanied by antibody depositions and increased levels of microglia after immunization with retinal antigens.
2012
BackgroundAntibodies against retinal and optic nerve antigens are detectable in glaucoma patients. Recent studies using a model of experimental autoimmune glaucoma demonstrated that immunization with certain ocular antigens causes an immun-mediated retinal ganglion cell loss in rats.Methodology/principal findingsRats immunized with a retinal ganglion cell layer homogenate (RGA) had a reduced retinal ganglion cell density on retinal flatmounts (p = 0.007) and a lower number of Brn3(+) retinal ganglion cells (p = 0.0001) after six weeks. The autoreactive antibody development against retina and optic nerve was examined throughout the study. The levels of autoreactive antibodies continuously in…
Intravitreal Docosahexaenoic Acid in a Rabbit Model: Preclinical Safety Assessment
2014
PurposeThe purpose of the present study was to evaluate the retinal toxicity of a single dose of intravitreal docosahexaenoic acid (DHA) in rabbit eyes over a short-term period.MethodsSixteen New Zealand albino rabbits were selected for this pre-clinical study. Six concentrations of DHA (Brudy Laboratories, Barcelona, Spain) were prepared: 10 mg/50 µl, 5 mg/50 µl, 2'5 mg/50 µl, 50 µg/50 µl, 25 µg/50 µl, and 5 µg/50 µl. Each concentration was injected intravitreally in the right eye of two rabbits. As a control, the vehicle solution was injected in one eye of four animals. Retinal safety was studied by slit-lamp examination, and electroretinography. All the rabbits were euthanized one week a…
Metabolic effects of the obstructive sleep apnea syndrome and cardiovascular risk
2008
The obstructive sleep apnea syndrome (OSAS) is characterized by collapse of the upper airway during sleep, recurring apneas, intermittent hypoxemia and daytime somnolence. OSAS is often associated with obesity, and its prevalence is expected to rise due to the obesity epidemics worldwide. OSAS is associated with increased cardiovascular risk which appears to be normalized by treatment with nasal continuous positive airway pressure (nCPAP) during sleep, suggesting an independent role of OSAS in accelerating atherosclerosis. Insulin resistance (IR) and the metabolic syndrome (MetS) are often found in OSAS patients, but the relative role played by OSAS and obesity is still unclear. Both OSAS a…
THE EFFECTS OF AGING ON DOPAMINERGIC NEUROTRANSMISSION A microPET STUDY OF [11C]-raclopride BINDING IN THE AGED RODENT BRAIN
2010
Rodent models are frequently used in aging re search to investigate biochemical age effects and aid in the development of therapies for pathological and non pathological age related degenerative processes In order to validate the use of animal models in aging research and pave the way for longitudinal intervention based animal studies, the consistency of cerebral aging processes across species needs to be evaluated The dopaminergic system seems particularly susceptible to the aging process, and one of the most consistent findings in human brain aging research is a decline in striatal D2-like receptor (D2R) availability, quantifiable by positron emission tomography (PET) imaging In this stud…
Chronic antidepressant treatment induces contrasting patterns of synaptophysin and PSA-NCAM expression in different regions of the adult rat telencep…
2007
Structural modifications occur in the brain of severely depressed patients and they can be reversed by antidepressant treatment. Some of these changes do not occur in the same direction in different regions, such as the medial prefrontal cortex, the hippocampus or the amygdala. Differential structural plasticity also occurs in animal models of depression and it is also prevented by antidepressants. In order to know whether chronic fluoxetine treatment induces differential neuronal structural plasticity in rats, we have analyzed the expression of synaptophysin, a protein considered a marker of synaptic density, and the expression of the polysialylated form of the neural cell adhesion molecul…
Heme oxygenase-1 regulates the progression of K/BxN serum transfer arthritis.
2012
Background Heme oxygenase-1 (HO-1) is induced in many cell types as a defense mechanism against stress. We have investigated the possible role of endogenous HO-1 in the effector phase of arthritis using the K/BxN serum transfer model of arthritis in HO-1 heterozygous and homozygous knock-out mice. Methodology/Principal Findings Arthritis was induced in C57/Black-6 xFVB (HO-1+/+, HO-1+/− and HO-1−/−) mice by intraperitoneal injection of 150 µl serum from arthritic K/BxN mice at days 0 and 2. Blood was collected and animals were sacrificed at day 10. Histological analysis was performed in ankle sections. The levels of inflammatory mediators were measured in serum and paw homogenates by enzyme…
Short-term effect of zoledronic acid upon fracture resistance of the mandibular condyle and femoral head in an animal model
2013
Objective: The aim of this study was to compare the effects in terms of resistance to fracture of the mandibular condyle and femoral head following different doses of zoledronic acid in an animal model. Study design: A total of 80 adult male Sprague-Dawley rats were included in a prospective randomized study. The animals were randomly divided into four groups of 20 rats each. Group 1 (control) received sterile saline solution, while groups 2, 3 and 4 received a accumulated dose of 0.2 mg, 0.4 mg and 0.6 mg of zoledronic acid, respectively. The animals were sacrificed 28 days after the last dose, and the right hemimandible and the right femur were removed. The fracture strength was measured …
Glucocorticoid receptor knockdown decreases the antioxidant protection of B16 melanoma cells: an endocrine system-related mechanism that compromises …
2014
We previously reported an interorgan system in which stress-related hormones (corticosterone and noradrenaline), interleukin-6, and glutathione (GSH) coordinately regulate metastatic growth of highly aggressive B16-F10 melanoma cells. Corticosterone, at levels measured in tumor-bearing mice, also induces apoptotic cell death in metastatic cells with low GSH content. In the present study we explored the potential role of glucocorticoids in the regulation of metastatic cell death/survival during the early stages of organ invasion. Glucocorticoid receptor (GCR) knockdown decreased the expression and activity of γ-glutamylcysteine synthetase (γ-GCS), the rate-limiting step in GSH synthesis, in …
Local Delivery of Nimodipine by Prolonged-Release Microparticles—Feasibility, Effectiveness and Dose-Finding in Experimental Subarachnoid Hemorrhage
2012
Background and purposeTo investigate the effect of locally applied nimodipine prolonged-release microparticles on angiographic vasospasm and secondary brain injury after experimental subarachnoid hemorrhage (SAH).Methods70 male Wistar rats were categorized into three groups: 1) sham operated animals (control), 2) animals with SAH only (control) and the 3) treatment group. SAH was induced using the double hemorrhage model. The treatment group received different concentrations (20%, 30% or 40%) of nimodipine microparticles. Angiographic vasospasm was assessed 5 days later using digital subtraction angiography (DSA). Histological analysis of frozen sections was performed using H&E-staining as …