Search results for "acetate"
showing 10 items of 756 documents
Staphylococcal α-toxin provokes coronary vasoconstriction and loss in myocardial contractility in perfused rat hearts: Role of thromboxane generation
2000
Background —Cardiac performance is severely depressed in septic shock. Endotoxin has been implicated as the causative agent in Gram-negative sepsis, but similar abnormalities are encountered in Gram-positive sepsis. We investigated the influence of the major exotoxin of Staphylococcus aureus, staphylococcal α-toxin, in isolated perfused rat hearts. Methods and Results —α-Toxin 0.25 to 1 μg/mL caused a dose-dependent increase in coronary perfusion pressure that more than doubled. In parallel, we noted a decrease in left ventricular developed pressure and the maximum rate of left ventricular pressure rise (dP/dt max ), dropping to a minimum of <60% of control. These changes were accompani…
Chronic Moderate Hyperammonemia Impairs Active and Passive Avoidance Behavior and Conditional Discrimination Learning in Rats
2000
Abstract The cerebral dysfunction associated with hepatic encephalopathy is generally considered to have hyperammonemia as one of its main causes. Hyperammonemia impairs the neuronal glutamate–nitric oxide–cyclic GMP pathway and the induction of NMDA receptor-dependent long-term potentiation in the hippocampus. We studied the performance of pre/neonatally and postnatally exposed rats to hyperammonemia on active avoidance, passive avoidance, and conditional discrimination tasks. Pre/neonatal hyperammonemia slowed learning of active avoidance behaviors and impaired memory for the passive avoidance task while postnatal hyperammonemia impaired learning on the conditional discrimination task. Hy…
Thyroid autoimmunity and dysfunction in multiple sclerosis patients during long-term treatment with interferon beta or glatiramer acetate: an Italian…
2014
Few long-term follow-up data are available on thyroid dysfunction (TD) in multiple sclerosis (MS) patients treated with glatiramer acetate (GA) or with interferon-beta (IFNb). In a cohort of 787 relapsing-remitting MS (RRMS) patients whom were followed up for 8 years, we observed an increased prevalence of TD and thyroid autoimmunity (TA) within the first year of IFNb treatment, regardless of the dose or frequency of administration, while no change was observed with GA treatment. The increased prevalence of TD and TA within the first year of IFNb treatment suggested the need for close monitoring of thyroid function and autoimmunity, though only during the first year of IFNb treatment. © Th…
Estradiol reduces F2α-isoprostane production in cultured human endothelial cells
2002
Free radical-generated F2α-isoprostanes are a group of compounds with vasoconstrictor properties. To investigate whether estradiol exerts antioxidant actions modifying F2α-isoprostane production, cultured human umbilical vein endothelial cells were exposed to estradiol and other compounds and F2α-isoprostanes were measured in culture medium. Exposure to 1 and 10 nM estradiol for 24 h reduced F2α-isoprostane production by 36 and 49%, respectively ( P < 0.001 vs. control). Exposure to antiestrogens alone (ICI-182780 or EM-652) slightly reduced F2α-isoprostanes ( P < 0.05 vs. control), but much less than exposure to estradiol ( P < 0.05). ICI-182780 reversed the estradiol-induced redu…
Contact sensitizers modulate mechanisms of receptor-mediated endocytosis but not fluid-phase endocytosis in murine epidermal Langerhans cells.
1995
In order to define the influence of contact allergens on the fluid-phase endocytosis (FPE) of soluble molecules of murine epidermal Langerhans cells (LC), we studied the internalization of FITC-labeled bovine serum albumin (FITC-BSA), TRITC-labeled dextrane (TRITC-DEX) as well as horseradish peroxidase by LC. A 3-parameter flow-cytometric technique was performed for quantification of internalized FITC-BSA in LC using quantum red-labeled reagents for detection of la-antigen expression by LC and propidium iodide for exclusion of dead cells from analysis. A temperature-dependent rapid accumulation of FITC-BSA was noticed in time-course studies reaching a plateau between 1 and 2 h of in vitro c…
Antiulcer activity of Cyperus alternifolius in relation to its UPLC-MS metabolite fingerprint: A mechanistic study
2019
Abstract Background Gastric ulcer is one of the main prevalent gastrointestinal multi-etiological disorders with many associated complications and adverse effects. Our aim was to develop safer antiulcer therapies based on methanol or ethyl acetate extracts of tubers and aerial parts from Cyperus alternifolius. Methods Gastric ulceration was experimentally generated by administration of single oral doses of indomethacin (30 mg/kg) to fasted rats. The animals received methanol or ethyl acetate extracts of C. alternifolius tuber and methanol or ethyl acetate extracts of aerial parts at two dose levels (50 or 100 mg/kg). Ranitidine (50 mg/kg) was used as standard anti-ulcer drug. After 4 h, the…
Studies on the Effects of the Antiandrogen Cyproterone Acetate on Social Encounters Between Pairs of Male Mice
1988
An attempt was made in two experiments to reinvestigate the effects of the antiandrogen cyproterone acetate (CA) on mouse social behavior in a variety of ethologically-assessed paired encounters. The data confirm that CA reduces offense (threat and attack) in animals when both subjects receive the material but that CA has no such action in other pairings. This suggests that CA's major suppressive effect on "hostility" is expressed in mice via a reduction in "attack-promoting" pheromone production. Indeed, there was evidence in the more chronic study that CA, could augment (via a central mechanism?) offense in subjects paired with docile anosmic opponents. Changes in defense were largely res…
Acute ammonia toxicity is mediated by the NMDA type of glutamate receptors
1992
AbstractPrevious experiments in our laboratory suggested that ammonium toxicity could be mediated by the NMDA type of glutamate receptors. To assess this hypothesis we tested if MK-801, a specific antagonist of the NMDA receptor, is able to prevent ammonium toxicity. Mice and rats were injected i.p. with 12 and 7 mmol/kg of ammonium acetate, respectively, 73% of the mice and 70% of the rats died. However, when the animals were injected i.p. with 2 mg/kg of MK-801, 15 min before ammonium injection, only 5% of the mice and 15% of the rats died. The remarkable protection afforded by MK-801 indicates that ammonia toxicity is mediated by the NMDA receptor.
Dynamics of ketone body metabolism in diabetic rats.
1972
Steady state blood levels of ketone bodies during infusions of acetoacetate at various rates have been compared in healthy and diabetic rats. The characteristics of the metabolic elimination of ketone bodies from the blood are completely changed in diabetic rats. Whereas steady state levels of ketone bodies increase linearly with the infusion rate in healthy rats, this increase is exponential in diabetic animals. This difference, which is due to an impaired metabolic elimination, becomes evident only above a dosage of 50 μmoles acetoacetate per kg per min. Chronic treatment with insulin for 4–6 days, but not acute insulin injection, restores the capacity of diabetic rats to metabolize keton…
Granulocyte integrins before and after activation in acute ischaemic stroke.
2001
We examined in 19 subjects with acute ischaemic stroke (AIS) the PMN integrin pattern (CD11a, CD11b, CD11c, CD18), using indirect immunofluorescence and adopting a flow cytometer, at baseline and during activation, prolonged for 5 and 15 min, with 4-phorbol 12-myristate 13-acetate (PMA). At baseline, an increase in the expression of CD11c and CD18 and a decrease in the CD11b were evident in AIS subjects compared to normals. After activation, we found in normals a constant and significant increase of all PMN adhesive molecules, while in AIS subjects, we found an increase in CD11b and CD18, a decrease in CD11a and no variation in CD11c. While the basal upregulation of CD11c and CD18 may depen…