Search results for "Ley"
showing 10 items of 1218 documents
Kinetics of tienilic acid bioactivation and functional generation of drug–protein adducts in intact rat hepatocytes
2005
13 pages; Drug-induced autoimmune hepatitis is among the most severe hepatic idiosyncratic adverse drug reactions. Considered multifactorial, the disease combines immunological and metabolic aspects, the latter being to date much better known. As for many other model drugs, studies on tienilic acid (TA)-induced hepatitis have evidenced the existence of bioactivation during the hepatic oxidation of the drug, allowing the identification of the neoantigen of anti-LKM2 autoantibodies and the pathway responsible for its formation. However, most of these results are based on the use of microsomal fractions whose relevance to the liver in vivo still needs to be established. In the more complex int…
A Microassay for Measuring Glycogen in 96-Well-Cultured Cells
1996
Abstract This study describes a rapid, sensitive, and automated spectrophotometric enzymatic microassay that measures the intracellular glycogen of primary cultured hepatocytes and other cultured cells in 96-well plates and can be adapted for other samples that are transferred to these plates. The procedure involves in situ disruption of cells, followed by hydrolysis of glycogen into glucosyl units by fungal glucoamylase (exo-1,4-α- D -glucosidase, EC 3.2.1.3), and glucose determination with the glucose oxidase colorimetric method. The color intensity can be measured in conventional ELISA readers, and the data can be fed to an on-line computer for rapid processing. The advantages of this me…
Neuroprotection by erythropoietin administration after experimental traumatic brain injury.
2007
A large body of evidence indicates that the hormone erythropoietin (EPO) exerts beneficial effects in the central nervous system (CNS). To date, EPO's effect has been assessed in several experimental models of brain and spinal cord injury. This study was conducted to validate whether treatment with recombinant human EPO (rHuEPO) would limit the extent of injury following experimental TBI. Experimental TBI was induced in rats by a cryogenic injury model. rHuEPO or placebo was injected intraperitoneally immediately after the injury and then every 8 h until 2 or 14 days. Forty-eight hours after injury brain water content, an indicator of brain edema, was measured with the wet-dry method and bl…
Neuroprotective potential of erythropoietin and darbepoetin alfa in an experimental model of sciatic nerve injury. Laboratory investigation.
2007
Object The objectives of this study were to examine whether the systemic administration of recombinant human erythropoietin (rHuEPO) and its long-lasting derivative darbepoetin alfa expedited functional recovery in a rat model of sciatic nerve injury, and to compare the effects of these agents in the model. Methods Thirty male Sprague–Dawley rats received a crush injury to the left sciatic nerve and subsequently underwent either placebo treatment, daily injections of rHuEPO, or weekly injections of darbepoetin alfa. Results Both rHuEPO and darbepoetin alfa were effective in reducing neurological impairment and improving compound muscle action potentials following nerve injury. Darbepoetin …
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 …
Sex-dependent changes in the pulmonary vasoconstriction potential of newborn rats following short-term oxygen exposure
2012
Chronic exposure to supplemental oxygen (O(2)) induces lung damage and mortality in a sex-dependent manner. The effect of short-term hyperoxia on the newborn pulmonary vasculature is unknown but is, however, of clinical significance in the neonatal resuscitation context. We hypothesize that short-term hyperoxia has a sex-dependent effect on the pulmonary vasculature.Following 1-h 100% O(2) exposure, the pulmonary arteries and lung tissues of newborn rats were evaluated.Superoxide dismutase 3 (SOD3) expression in female pups' lungs was increased as compared with that in the lungs of male pups. As compared with air-treated pups, the response of male pups to thromboxane was increased by O(2), …
Dentate spikes and learning : disrupting hippocampal function during memory consolidation can improve pattern separation
2018
Hippocampal dentate spikes (DSs) are short-duration, large-amplitude fluctuations in hilar local field potentials and take place while resting and sleeping. During DSs, dentate gyrus granule cells increase firing while CA1 pyramidal cells decrease firing. Recent findings suggest DSs play a significant role in memory consolidation after training on a hippocampus-dependent, nonspatial associative learning task. Here, we aimed to find out whether DSs are important in other types of hippocampus-dependent learning tasks as well. To this end, we trained adult male Sprague-Dawley rats in a spatial reference memory task, a fixed interval task, and a pattern separation task. During a rest period im…
Shunting of the Microcirculation After Mesenteric Ischemia and Reperfusion Is a Function of Ischemia Time and Increases Mortality
2006
Shunting of the microcirculation contributes to the pathology of sepsis and septic shock. The authors address the hypothesis that shunting of the microcirculation occurs after superior mesenteric artery occlusion (SMAO) and reperfusion, and explore functional consequences.Spontaneously breathing animals (rats) (n = 30) underwent SMAO for 0 (controls), 30 (SMAO_30) or 60 min (SMAO_60) followed by reperfusion (4 h) with normal saline. Leukocyte-endothelial interactions in mesenteric venules were quantified in an exteriorized ileal loop using intravital microscopy. Abdominal blood flow was recorded continuously, and arterial blood gases were analyzed at intervals. The above groups were matched…
Replenishment of glutathione levels improves mucosal function in experimental acute colitis.
2000
Because reactive oxygen species (ROS) have been implicated as mediators of inflammatory bowel disease (IBD), the purpose of the present work was to determine the functional role of mucosal GSH in the trinitrobenzenesulfonic acid in 50% ethanol (TNBS+ethanol)-induced colitis in rats. Mucosal samples were taken to evaluate the temporal relationship between the extent of injury, the levels of glutathione (GSH) during acute colitis induced by TNBS+ethanol, and the effect of N-acetylcysteine (NAC) administration. In vitro assays revealed the interaction of TNBS with GSH leading to the almost instantaneous disappearance of GSH, while the reductive metabolism of TNBS by GSSG reductase generated RO…
Nuclear fos domains in transcriptionally activated supraoptic nucleus neurons
1993
This study has analysed by light and electron microscopy immunolocalization the nuclear pattern of distribution of Fos-related proteins in supraotic neurons. Two experimental models of transcriptional activation have been used: sustained, global transcriptional activation, at relatively near physiological conditions, by six days of chronic intermittent salt loading; and superinduction of c-fos gene by this salt loading regime plus cycloheximide treatment for 4 h. In the first condition, the ultrastructural analysis showed a distribution of Fos-like immunoreactivity on the reticular network of dispersed chromatin that extends between the nucleolar surface and the nuclear envelope, whereas th…