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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Evaluation of Extended Dual Antiplatelet Therapy with Aspirin and Clopidogrel Among Men and Women Patients at El Rio Health Center

Jaeger, Alina, Pham, Kimberly, Kennedy, Amy January 2016 (has links)
Class of 2016 Abstract / Objectives: Analyze trends in prescribing extended dual antiplatelet therapy (DAPT) with aspirin and clopidogrel between men and women patients at El Rio community health center. Methods: Patients at a community health center who were on DAPT for longer than one year were identified through retrospective chart review. Demographic and descriptive data were recorded, including patient age, gender, indication for therapy, and type of prescriber. Based on prescribing guidelines, acute coronary syndrome (ACS) with bare-metal stent or drug-eluting stent, and drug-eluting stent without ACS were considered to be appropriate indications of extended DAPT. All other indications were considered inappropriate. Results: Data was collected for 27 men (mean age = 68; SD = 9.82; 70.4% hispanic or latino) and 31 women (mean age = 70; SD = 10.49; 83.9% hispanic or latino). Dual antiplatelet therapy was appropriately prescribed for 17 men and 20 women (63% and 64.5%, p=0.08). Conclusions: Overall, the difference in adherence to prescribing guidelines for men and women was not significant.
62

An investigation into the neuroprotective properties of acetylsalicylic acid and acetaminophen

Maharaj, Himant January 2005 (has links)
The potent analgesic property of acetylsalicylic acid and acetaminophen makes these the most commonly used analgesics in the world. Easy accessibility and cost effectiveness of these agents are attractive to patients seeking pain relief. However, the abuse of nonnarcotic analgesics such as acetaminophen and acetylsalicylic acid by alcoholics and patients seeking to relieve dysphoric moods is well documented. These agents therefore impact on the brain neurotransmitter levels and therefore all processes involved in the synthesis and metabolism of neurotransmitters may be affected. The use of non-narcotic analgesics has been reported to reduce the incidence of neurodegenerative disorders such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). The mode of action by which acetylsalicylic acid and acetaminophen elicit neuroprotection is however unclear as many mechanisms of action have been inconclusively postulated. The first part of this study aims to elucidate the various mechanisms by which acetylsalicylic acid and acetaminophen affect the enzymes responsible for the catabolism of tryptophan, which is a precursor for the mood elevating neurotransmitter serotonin, as well as to investigate whether these agents alter the interplay between serotonin and pineal indole metabolism. The second part of this study focuses on the neuroprotective properties of acetylsalicylic acid and acetaminophen utilizing the neurotoxic metabolite of the kynurenine pathway, quinolinic acid and the potent Parkinsonian neurotoxin, 1-methyl-4-phenylpyridinium (MPP+). The ability of acetylsalicylic acid and acetaminophen to alter TRP metabolism was determined by investigating the effects of these agents on the primary enzymes of the kynurenine pathway i.e. tryptophan 2, 3-dioxygenase and indoleamine 2,3-dioxygenase as well as to investigate whether these agents would have any effects on 3-hydroxyanthranilic acid oxygenase. 3-Hydroxyanthranilic acid oxygenase is the enzyme responsible for the synthesis of quinolinic acid. Acetylsalicylic acid and acetaminophen alter tryptophan metabolism by inhibiting tryptophan 2, 3-dioxygenase and indoleamine 2,3-dioxygenase thus increasing the availability of tryptophan for the production of serotonin. Acetylsalicylic acid and acetaminophen also inhibit 3-hydroxyanthranilic acid oxygenase thus implying that these agents could reduce quinolinic acid production. Acetaminophen administration in rats induces a rise in serotonin and norepinephrine in the forebrain. Acetylsalicylic acid curtails the acetaminophen-induced rise in brain norepinephrine levels as well as enhances serotonin metabolism, indicating that analgesic preparations containing both agents would be advantageous, as this would prevent acetaminophen-induced mood elevation. The results from the pineal indole metabolism study show that acetylsalicylic acid enhances pineal metabolism of serotonin whereas acetaminophen induces an increase in melatonin levels in the pineal gland. Neuronal damage due to oxidative stress has been implicated in several neurodegenerative disorders such as AD and PD. The second part of the study aims to elucidate and characterize the mechanism by which acetylsalicylic acid and acetaminophen afford neuroprotection. The hippocampus is an important region of the brain responsible for memory. Agents such as quinolinic acid that are known to induce stress in this area have detrimental effects and could lead to various types of dementia. The striatum is also a vulnerable region to oxidative stress and hence (MPP+), which is toxic for this particular region of the brain, was also used as a neurotoxin. The results show that ASA and acetaminophen alone and in combination, are potent superoxide anion scavengers. In addition, the results imply that these agents offer protection against oxidative stress and lipid peroxidation induced by several neurotoxins in rat brain particularly, the hippocampus and striatum. Histological studies, using Nissl staining and Acid fuchsin, show that acetylsalicylic acid and acetaminophen are able to protect hippocampal neurons against quinolinic acidinduced necrotic cell death. Immunohistochemical investigations show that QA induces apoptotic cell death in the hippocampus, which is inhibited by ASA and acetaminophen. In addition, ASA and acetaminophen inhibited MPP+ induced apoptotic cell death in the rat striatum. The study also sought to elucidate possible mechanisms by which ASA and acetaminophen exert neuroprotective effects in the presence of MPP+ as these agents are shown to prevent the MPP+-induced reduction in dopamine levels. The results show that acetylsalicylic acid and acetaminophen inhibit the action of this neurotoxin on the mitochondrial electron transport chain, a common source of free radicals in the cell. In addition, these agents were shown to block the neurotoxic effects of MPP+ on the enzymatic defence system of the brain i.e. superoxide dismutase, glutathione peroxidase and catalase. The reduction in glutathione levels induced by MPP+ is significantly inhibited by acetylsalicylic acid and acetaminophen. The results imply that these agents are capable of not only scavenging free radicals but also enhance the cell defence mechanism against toxicity in the presence of MPP+. These agents also block the MPP+-induced inhibition of dopamine uptake into the cell. This would therefore reduce auto-oxidation of dopamine thus implying another mechanism by which these agents exert a neuroprotective role in MPP+-induced neurotoxicity. The discovery of neuroprotective properties of acetylsalicylic acid and acetaminophen is important considering the high usage of these agents and the increased incidence in neurological disorders. The findings of this thesis point to the need for clinical studies to be conducted as the results show acetylsalicylic acid and acetaminophen to have a definite role to play as antioxidants. This study therefore provides novel information regarding the neuroprotective effects of these agents and favours the use of these agents in the treatment of neurodegenerative disorders, such as AD and PD, in which oxidative stress is implicated.
63

A comparison of the effects of aspirin, sodium salicylate, and acetate on cells in vitro

Barron, Roger Scott 01 January 1973 (has links)
Salicylic acid and its concern have long been used for the management of pain, fever, and inflammation. Of this group, acetyl-salicylic acid, or aspirin (ASA) has proved to be the most potent in each case. Although hydrolysis, the first step in biotransformation of aspirin takes place very rapidly, many workers feel that the greater effectiveness is due to a unique action of the intact molecule; however, others disagree. In this study, the effects of aspirin and in vitro were compared in order to obtain a greater amount of information relating to the problem.
64

L'aspirine récapitule les caractéristiques de la restriction calorique / Aspirin recapitulates features of caloric restriction

Castoldi, Francesca 12 December 2018 (has links)
L'autophagie est un processus d'auto-digestion durant lequel les cellule dégradent leurs propres composants afin de maintenir l’homéostasie en conditions basales. L'autophagie est donc nécessaire à l’échelle de la cellule et de l’organisme car elle joue un rôle dans l’élimination des organites endommagés et des agrégats de protéines potentiellement nocifs et a la capacité de mobiliser les métabolites essentiels des réserves énergétiques en conditions de stressLa détérioration des fonctions cellulaires et au niveau de l’organisme liée à l'âge est associée à une dérégulation des voies de détection des nutriments ainsi qu’à une autophagie déficiente. La réactivation du flux autophagique peut prévenir ou améliorer ces dysfonctionnements métaboliques liés à l'âge. Les composés non toxiques capables de réduire les taux globaux d'acétylation des protéines et d'induire l'autophagie ont été classés dans la catégorie des agents mimétiques de restriction calorique (CRMs, de l’anglais « caloric restriction mimetic »). Nous montrons ici que l'aspirine et son métabolite actif, le salicylate, induisent une autophagie en raison de leur capacité à inhiber l'activité acétyltransférase de EP300. Alors que le salicylate stimule le flux autophagique dans les cellules « Wild Type », il ne permet pas d’augmenter le niveau d'autophagie dans les cellules déficientes en EP300, ni dans les cellules dans lesquelles EP300 endogène a été remplacé par les mutants EP300 résistants au salicylate. En conséquence, l'activité pro-autophagique de l'aspirine et du salicylate sur le nématode Caenorhabditis elegans est perdue lorsque l'expression de l'orthologue EP300 cpb-1 est réduite. Ces résultats permettent de conclure que l'aspirine est un CRM dont le mécanisme est conservé au cours de l’évolution. / Autophagy is a self-digestion process in which cell degrades its own components in order to maintain homeostasis in basal conditions; autophagy is required for the maintenance of cellular and organismal fitness due to its role in eliminating damaged organelles and potentially harmful protein aggregates, as well as its unique capacity to mobilize essential metabolites from complex energy stores in conditions of stress.The age-associated deterioration in cellular and organismal functions associates with dysregulation of nutrient-sensing pathways and disabled autophagy. The reactivation of autophagic flux may prevent or ameliorate age-related metabolic dysfunctions. Non-toxic compounds endowed with the capacity to reduce the overall levels of protein acetylation and to induce autophagy have been categorized as caloric restriction mimetics (CRMs). Here, we show that aspirin or its active metabolite salicylate induce autophagy by virtue of their capacity to inhibit the acetyltransferase activity of EP300. While salicylate readily stimulates autophagic flux in control cells, it fails to further increase autophagy levels in EP300-deficient cells, as well as in cells in which endogenous EP300 has been replaced by salicylate-resistant EP300 mutants. Accordingly, the pro-autophagic activity of aspirin and salicylate on the nematode Caenorhabditis elegans is lost when the expression of the EP300 ortholog cpb-1 is reduced. Altogether, these findings identify aspirin as an evolutionary conserved CRM.
65

Analysis of essential thrombocythemia and its treatment

Cowart, Cade Alan 28 March 2021 (has links)
Essential thrombocythemia (ET) is a rare myeloproliferative neoplasm affecting 43.7 out of every 100,000 people in the United States. The disease is characterized by abnormally high platelet counts, mutational abnormalities in Janus Kinase 2 (JAK2)/Calreticulin (CALR)/myeloproliferative leukemia virus oncogene (MPL), and increased megakaryocyte production and differentiation. The average age of onset for patients with ET is between 65-70 years, but recent studies have demonstrated a downward trend in the age of diagnosis. Mechanistically, ET mutations cause the dimerization of JAK and upregulation of the JAK-STAT pathways. Common treatment approaches seek to use cytoreduction and platelet inhibition to lower the risk of a thrombotic event. Hydroxyurea and low-dose aspirin have been the gold-standard of treatment for ET patients. This thesis sought to compare the current available therapy with second-line treatments and investigational treatments. Anagrelide is a key second-line treatment for ET that is used in the event of intolerance to hydroxyurea. It acts through cytoreductive mechanisms which result in a decreased platelet count. Major bleeding is a severe adverse event associated with anagrelide. Interferons are another second-line defense in the treatment of ET despite a lack of FDA approval for this indication. Interferons act directly to reduce platelet counts and, unlike other drug classes, mount an immunological response against the JAK2 stem cells to reduce the allelic burden. An immunological approach to ET may be key to the sustained treatment of the disorder without a daily dosing regimen. Despite the promise of interferons, severe adverse effects limit the adherence of many patients to this class of drugs. JAK inhibitors are an investigational drug class that acts directly through the JAK-STAT pathway. JAK inhibitors have shown little efficacy in the treatment of ET and may be better suited for treatment in combination therapies. Telomerase inhibitors are one such investigational drug class that may pair well with JAK inhibitors for the treatment of ET. All of these drug classes were compared to hydroxyurea with respect to their pharmacokinetics, pharmacodynamics, and patient evaluation. Hydroxyurea and low-dose aspirin showed superiority in comparison to other drug classes due to their low toxicity profile and minimum adverse side-effects, high oral bioavailability and wide distribution, high adherence, and production of the most uniform response to reducing thrombotic events and platelet counts. The interferon drug class shows unique potential for the treatment of ET and should be placed above the second-line treatment standard of anagrelide due to its benefits in treatment of younger and pregnant patients. Interferons are the only class of drug for the treatment of ET that did not increase the risk of drug-related leukemogenic transformations. Despite non-adherence due to side-effects and lack of an oral administration, interferons are superior to anagrelide due to their longer dosing interval and immunological attack on JAK2 stem cells. Treatment of ET with anagrelide has shown similar efficacy to hydroxyurea and interferons in platelet reduction and rivals hydroxyurea in the prevention of thrombotic risk. Despite this benefit, the risk of bleeding associated with anagrelide is a significant disadvantage. Hydroxyurea and low-dose aspirin remain the current standard of treatment for patients with ET, although new approaches may soon be available.
66

Aspirin v sekundární prevenci ischemické cévní mozkové příhody. / Aspirin in the secondary prevention of ischemic stroke

Adámek, Tomáš January 2015 (has links)
Introduction: The recurrence of the cerebral ischemic stroke after a history of TIA or ischemic stroke is 3-4% per year. One way of reducing the risk of reccurence is using antiplatelet therapy. The aim of our study was to investigate the effect of aspirin. Even though, newer antiplatelet drugs were developed, their risk/benefit profile has not been proved to be better than aspirin. Reasons for using aspirin in secondary prevention are: the longest experience, clearly proven effect in many studies and low price. On the other hand, aspirin prevents only 25% of strokes, thus there is wide space for searching for causes of failed therapy and alternative therapeutic ways. Noncompliance of aspirin use and embolic events are usually indicated as the most common causes of an ineffective therapy. The goal of our study was to find the antiplatelet therapy effectivity in patients with history of stroke treated with aspirin in daily dose of 100mg. We assured 100% compliance among these patients and as much as possible minimalized a likelihood of embolic causes of strokes. What is more, we tried to find out whether an insuffient suppression of 11-dehydrotromboxane B2 correlates with comorbidities, other used medication or laboratory parameters. Furthermore, whether by administrating an increased dose of...
67

What Is the Appropriate Duration of Dual Antiplatelet Therapy?

Mospan, Cortney M. 01 January 2016 (has links)
Healthcare providers often are faced with the challenge of determining an appropriate length of dual antiplatelet therapy (DAPT) for patients who have had percutaneous coronary intervention and stent placement. This is an especially challenging clinical decision for patients with drug-eluting stents, as several studies show different results when assessing risk and benefit.
68

Aspirin Dose Dependently Inhibits the Interleukin-1β-Stimulated Increase in Inducible Nitric Oxide Synthase, Nitric Oxide, and Prostaglandin E<sub>2</sub> Production in Rat Ovarian Dispersates Cultured in Vitro

Carnovale, David E., Fukuda, Aisaku, Underhill, Derek C., Laffan, John J., Breuel, Kevin F. 18 April 2001 (has links)
Objective: Determine if aspirin inhibits the IL-1β-stimulated expression of inducible nitric oxide synthase (iNOS), nitric oxide (NO), and prostaglandin E2 (PGE2) in rat ovarian dispersates cultured in vitro. Design: Prospective, controlled in vitro study. Setting: Academic research laboratory. Animals: Ovaries collected from immature rats. Intervention(s): Ovaries were collected from immature rats and enzymatically dispersed. Ovarian dispersates were placed into plates containing media alone or media supplemented with IL-1β (100 U/mL) and varying concentrations of aspirin (0, 1, 3, 5 and 10 mM). Ovarian dispersates were cultured in a humidified environment of 5% CO2 in air at 37°C for 24 or 48 hours. Main Outcome Measure(s): Twenty-four- and 48-hour iNOS, nitrite (a stable metabolite of NO), and PGE2 levels were determined from ovarian dispersates cultured in vitro. Result(s): Administration of IL-1β increased nitrite and PGE2 levels over that observed in the control group after culture of ovarian dispersates for 24 and 48 hours. Aspirin dose dependently reduced the IL-1β-stimulated increase in nitrite production from ovarian dispersates after culture for 24 and 48 hours. Aspirin completely (24 hours) or dose dependently (48 hours) prevented the IL-β-stimulated increase in PGE2. Coadministration of IL-1β and aspirin (10 mM) attenuates IL-1β-stimulated iNOS expression after culture for 24 and 48 hours. Conclusion(s): Aspirin significantly inhibits the IL-1β-stimulated expression of iNOS, NO, and PGE2 in ovarian dispersates cultured in vitro.
69

Effects of 5’AMP-activated protein kinase agonists in horses with experimentally-induced insulin dysregulation

Timko, Kathryn January 2021 (has links)
No description available.
70

Elevated Troponin in the Absence of Acute Coronary Syndrome

Poe, Stacy A. 27 September 2013 (has links)
No description available.

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