996 resultados para DRUGS ADMINISTRATION
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Superparamagnetic iron oxide nanoparticles (SPIONs) are in clinical use for disease detection by MRI. A major advancement would be to link therapeutic drugs to SPIONs in order to achieve targeted drug delivery combined with detection. In the present work, we studied the possibility of developing a versatile synthesis protocol to hierarchically construct drug-functionalized-SPIONs as potential anti-cancer agents. Our model biocompatible SPIONs consisted of an iron oxide core (9-10 nm diameter) coated with polyvinylalcohols (PVA/aminoPVA), which can be internalized by cancer cells, depending on the positive charges at their surface. To develop drug-functionalized-aminoPVA-SPIONs as vectors for drug delivery, we first designed and synthesized bifunctional linkers of varied length and chemical composition to which the anti-cancer drugs 5-fluorouridine or doxorubicin were attached as biologically labile esters or peptides, respectively. These functionalized linkers were in turn coupled to aminoPVA by amide linkages before preparing the drug-functionalized-SPIONs that were characterized and evaluated as anti-cancer agents using human melanoma cells in culture. The 5-fluorouridine-SPIONs with an optimized ester linker were taken up by cells and proved to be efficient anti-tumor agents. While the doxorubicin-SPIONs linked with a Gly-Phe-Leu-Gly tetrapeptide were cleaved by lysosomal enzymes, they exhibited poor uptake by human melanoma cells in culture.
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FHWA and the Iowa Department of Transportation are proposing geometric and capacity improvements to the Interstate 29 and Interstate 80 mainline in Segment 3 and the I-80/I-29 East System interchange, the South Expressway interchange, the U.S. Highway 275 interchange, and the Madison Avenue interchange to to safely and efficiently of transportation in the City of Council Bluffs, the Iowa DOT is also proposing to eliminate several railroad alignments and to develop new, consolidated tracks in Segment 3.
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Description of the Proposed Action The Iowa Department of Transportation (Iowa DOT) and the Federal Highway Administration (FHWA) propose to improve a 3.9-mile segment of Iowa Highway 86 (IA 86) from Iowa Highway 9 (IA 9) to near the Minnesota border within Dickinson County, Iowa (the Project). The existing IA 86 has narrow travel lanes and shoulders, steep foreslopes, and poor vertical alignment. Environmental Assessment Availability The Environmental Assessment (EA) for the Project was signed on June 30, 2011, and distributed to selected federal, state, and local resource agencies on July 5, 2011, for review and comment. A Notice of Public Hearing and Environmental Assessment Availability was published in the legal section of the Estherville Daily News on July 5, 2011, and the Ocheyedan Press-Melvin News and Dickinson County News on July 6, 2011. Review and Comment Period A review and comment period was established for receipt of comments on the EA, with an expiration date of August 8, 2011. A public hearing for the Project was held at the Dickinson County Courthouse on July 21, 2011. The public hearing used a combined open forum and formal format. A transcript of this meeting has been prepared and is available upon request.
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Delta(9)-Tetrahydrocannabinol (THC) is frequently found in the blood of drivers suspected of driving under the influence of cannabis or involved in traffic crashes. The present study used a double-blind crossover design to compare the effects of medium (16.5 mg THC) and high doses (45.7 mg THC) of hemp milk decoctions or of a medium dose of dronabinol (20 mg synthetic THC, Marinol on several skills required for safe driving. Forensic interpretation of cannabinoids blood concentrations were attempted using the models proposed by Daldrup (cannabis influencing factor or CIF) and Huestis and coworkers. First, the time concentration-profiles of THC, 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) (active metabolite of THC), and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) in whole blood were determined by gas chromatography-mass spectrometry-negative ion chemical ionization. Compared to smoking studies, relatively low concentrations were measured in blood. The highest mean THC concentration (8.4 ng/mL) was achieved 1 h after ingestion of the strongest decoction. Mean maximum 11-OH-THC level (12.3 ng/mL) slightly exceeded that of THC. THCCOOH reached its highest mean concentration (66.2 ng/mL) 2.5-5.5 h after intake. Individual blood levels showed considerable intersubject variability. The willingness to drive was influenced by the importance of the requested task. Under significant cannabinoids influence, the participants refused to drive when they were asked whether they would agree to accomplish several unimportant tasks, (e.g., driving a friend to a party). Most of the participants reported a significant feeling of intoxication and did not appreciate the effects, notably those felt after drinking the strongest decoction. Road sign and tracking testing revealed obvious and statistically significant differences between placebo and treatments. A marked impairment was detected after ingestion of the strongest decoction. A CIF value, which relies on the molar ratio of main active to inactive cannabinoids, greater than 10 was found to correlate with a strong feeling of intoxication. It also matched with a significant decrease in the willingness to drive, and it matched also with a significant impairment in tracking performances. The mathematic model II proposed by Huestis et al. (1992) provided at best a rough estimate of the time of oral administration with 27% of actual values being out of range of the 95% confidence interval. The sum of THC and 11-OH-THC blood concentrations provided a better estimate of impairment than THC alone. This controlled clinical study points out the negative influence on fitness to drive after medium or high dose oral THC or dronabinol.
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A simple and sensitive LC-MS method was developed and validated for the simultaneous quantification of aripiprazole (ARI), atomoxetine (ATO), duloxetine (DUL), clozapine (CLO), olanzapine (OLA), sertindole (STN), venlafaxine (VEN) and their active metabolites dehydroaripiprazole (DARI), norclozapine (NCLO), dehydrosertindole (DSTN) and O-desmethylvenlafaxine (OVEN) in human plasma. The above mentioned compounds and the internal standard (remoxipride) were extracted from 0.5 mL plasma by solid-phase extraction (mix mode support). The analytical separation was carried out on a reverse phase liquid chromatography at basic pH (pH 8.1) in gradient mode. All analytes were monitored by MS detection in the single ion monitoring mode and the method was validated covering the corresponding therapeutic range: 2-200 ng/mL for DUL, OLA, and STN, 4-200 ng/mL for DSTN, 5-1000 ng/mL for ARI, DARI and finally 2-1000 ng/mL for ATO, CLO, NCLO, VEN, OVEN. For all investigated compounds, good performance in terms of recoveries, selectivity, stability, repeatability, intermediate precision, trueness and accuracy, was obtained. Real patient plasma samples were then successfully analysed.
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Cytomegalovirus (CMV) is generally considered the most significant pathogen to infect patients following organ transplantation. Significant improvements have been achieved in the management of CMV disease over recent years, especially since the introduction of oral drugs such as oral ganciclovir followed by valganciclovir (VGC), a prodrug of ganciclovir with enhanced bioavailability. Several randomized controlled trials have shown that VGC is an efficacious and convenient oral drug to prevent or treat CMV disease in solid-organ transplant recipients. In this article, we discuss the clinical and pharmacological experience with the use of VGC for the management of CMV in solid-organ transplant recipients. Finally, novel strategies to further reduce the incidence of CMV disease after transplantation are also reviewed.
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BACKGROUND: The risk of falls is the most commonly cited reason for not providing oral anticoagulation, although the risk of bleeding associated with falls on oral anticoagulants is still debated. We aimed to evaluate whether patients on oral anticoagulation with high falls risk have an increased risk of major bleeding. METHODS: We prospectively studied consecutive adult medical patients who were discharged on oral anticoagulants. The outcome was the time to a first major bleed within a 12-month follow-up period adjusted for age, sex, alcohol abuse, number of drugs, concomitant treatment with antiplatelet agents, and history of stroke or transient ischemic attack. RESULTS: Among the 515 enrolled patients, 35 patients had a first major bleed during follow-up (incidence rate: 7.5 per 100 patient-years). Overall, 308 patients (59.8%) were at high risk of falls, and these patients had a nonsignificantly higher crude incidence rate of major bleeding than patients at low risk of falls (8.0 vs 6.8 per 100 patient-years, P=.64). In multivariate analysis, a high falls risk was not statistically significantly associated with the risk of a major bleed (hazard ratio 1.09; 95% confidence interval, 0.54-2.21). Overall, only 3 major bleeds occurred directly after a fall (incidence rate: 0.6 per 100 patient-years). CONCLUSIONS: In this prospective cohort, patients on oral anticoagulants at high risk of falls did not have a significantly increased risk of major bleeds. These findings suggest that being at risk of falls is not a valid reason to avoid oral anticoagulants in medical patients.
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MEK kinase 1 (MEKK1) is a 196-kDa enzyme that is involved in the regulation of the c-Jun N-terminal kinase (JNK) pathway and apoptosis. In cells exposed to genotoxic agents including etoposide and cytosine arabinoside, MEKK1 is cleaved at Asp874 by caspases. The cleaved kinase domain of MEKK1, itself, stimulates caspase activity leading to apoptosis. Kinase-inactive MEKK1 expressed in HEK293 cells effectively blocks genotoxin-induced apoptosis. Treatment of cells with taxol, a microtubule stabilizing agent, did not induce MEKK1 cleavage in cells, and kinase-inactive MEKK1 expression failed to block taxol-induced apoptosis. MEKK1 became activated in HEK293 cells exposed to taxol, but in contrast to etoposide-treatment, taxol failed to increase JNK activity. Taxol treatment of cells, therefore, dissociates MEKK1 activation from the regulation of the JNK pathway. Overexpression of anti-apoptotic Bcl2 blocked MEKK1 and taxol-induced apoptosis but did not block the caspase-dependent cleavage of MEKK1 in response to etoposide. This indicates Bcl2 inhibition of apoptosis is, therefore, downstream of caspase-dependent MEKK1 cleavage. The results define the involvement of MEKK1 in the induction of apoptosis by genotoxins but not microtubule altering drugs.
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Abstract : Neonatal stroke occurs in 1 out of 4000 live births and usually leads to serious motor and cognitive disabilities. Ischemic brain injury results from a complex of pathophysiological events that evolve over space and time making it difficult to devise successful therapy. To date, there are no effective treatments for perinatal brain damage. Most clinical trials of neuroprotectaot drugs have failed because of their side-effects. For this reason it is important to find ways to target drugs specifically into the stressed cells. In this study we plan to contribute to the development of an efficient neuroprotective strategy against excitotoxic cell death in the neonate. In order to achieve this goal, several strategies were followed. A recently described phenomenon of induced endocytosis associated with excitotoxicity was more deeply investigated. As a simplified model we used dissociated cortical neurons exposed to an excitotoxic dose of NMDA, and we showed that this phenomenon depends on clathrin and dynamin. Using a model of neonatal focal cerebral ischemia, we demonstrated that the excitotoxicity-related endocytosis targets molecules such as TAT peptides into stressed neurons. These appear to be viable, raising the possibility of using this phenomenon as a doorway for neuroprotection. One part of the project was devoted to the study of the TAT-conjugated JNK inhibitory peptide, D-JNKI1. Adose-response study showed strong neuroprotection over a wide dose-range in the case of delayed administration (either intravenous or intraperitoneal). Since D-JNKI1 is aTAT-linked peptide, we investigated the role of its own NMDA-induced endocytosis in its neuroprotective efficacy. Furthermore, we showed that this endocytosis is JNK dependent, and that D-JNKI1 regulates its own uptake. We additionally studied the different types of cell death involved in a model of neonatal focal cerebral ischemia. Necrosis occurred rapidly in the center of the lesion whereas apoptosis and autophagic cell death occurred late at the lesion border. Inhibiting apoptosis was not protective, but use of autophagy inhibitor 3methyladenine provided a strong neuroprotection. Finally, combining two neuroprotectants that target different intracellular pathways was neuroprotective in a severe model of cerebral ischemia where neither of the drugs was efficient when administered individually. Résumé : L'ischémie néonatale connaît une incidence de 1 naissance sur 4000, entraînant généralement de sérieux dysfonctionnements moteurs et cognitifs. L'ischémie cérébrale résulte d'évènements physiopathologiques complexes qui évoluent dans l'espace et le temps rendant difficile la conception de thérapies efficaces. A l'heure actuelle, aucun traitement n'existe pour lutter contre les accidents vasculaires cérébraux qui se produisent autour de la naissance. La plupart des essais cliniques concernant des molécules neuroprotectrices ont échoué du fait de leurs effets secondaires néfastes. Pour cette raison, il est important de trouver des moyens de cibler les drogues dans les cellules stressées spécifiquement. Dans cette étude nous visons à participer au développement d'une stratégie neuroprotectrice efficace contre l'ischémie cérébrale chez le nouveau-né. Dans ce but, plusieurs stratégies ont été poursuivies. Un nouveau phénomène d'endocytose induite par un stimulus excitotoxique a été récemment décrit. Une partie de cette étude va consister à mieux comprendre ce phénomène. Pour céla, nous avons utilisé comme modèle d'étude simplifié des cultures dissociées de neurones corticaux exposées à une dose excitotoxique de NMDA. Nous avons ainsi montré que cette endocytose associée à l'excitotoxicité dépend de la clathrine et de la dynamine. A l'aide d'un modèle d'ischémie cérébrale focale chez le raton de 12 jours, nous avons démontré que cette endocytose induite par l'excitotoxicité permet de cibler des molécules diverses et en particulier les peptides TAT dans les neurones stressés. Ces neurones fortement endocytiques apparaissent comme étant encore viables, ouvrant la possibilité d'utiliser cette endocytose comme moyen d'entrée pour des molécules thérapeutiques. Une partie du projet a été consacrée à l'étude d'un inhibiteur de la voie JNK, couplé au TAT, appelé D-JNKI1. Des études de dose réponse du D-JNKI1 ont été réalisées chez l'animal, testant les effets d'une administration retardée en injection intraveineuse ou intra péritonéale. Ces études démontrent qu'une large gamme de dose permet d'obCenir une réduction de la taille de la lésion. Comme D-JNK11 est couplé au peptide TAT, nous avons étudié la contribution que sa propre endocytose lors de l'excitotoxicité apporte à ses effets protecteurs. Par ailleurs, nous avons montré que cette endocytose induite par l'excitotoxicité dépend de la voie de signalisation JNK et que D-JNK11 est donc capable de réguler sa propre entrée. Nous avons en parallèle étudié les différents types de mort cellulaires impliqués dans le développement de la lésion dans un modèle sévère d'ischémie cérébrale chez le raton nouveau-né. La mort cellulaire par nécrose se développe rapidement dans le centre de la lésion alors que les morts cellulaires par apoptose et autophagique vont apparaître plus tard et au bord de la lésion. Inhiber l'apoptose n'a pas permis de réduire la taille de la lésion alors que l'utilisation d'un inhibiteur d'autophagie, la 3-méthyladénine, procure une forte neuroprotection. Finalement, la combinaison de deux peptides qui ciblent différentes voies de signalisation intracellulaire permet d'obtenir une bonne protection dans le modèle d'ischémie sévère dans lequel aucun des deux peptides administré séparément n'a donné d'effets bénéfiques.
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The in vivo effects of Diaspirin Crosslinked Hemoglobin (DCLHb, Baxter Healthcare Corp.) on hematology and biochemistry are unknown. This study includes 6 calves (71.2+/-1.3 kg). In each animal a total of 2 litres of blood was exchanged for the same amount of hydroxylethyl starch (Haes, Fresenius) (n=3) or DCLHb (n=3), which is equivalent to 28cc/kg of blood substitute, over a period of 5 hours. The animals were allowed to survive 7 days. Blood samples were taken hourly during the perfusion protocol, at postoperative day (POD) 1, 2 and 7. ANOVA test was used for repeated measurements. Blood cell profiles were similar in both groups. Peak methemoglobinemia was 4.2% in the DCLHb group. Osmolarity was significantly higher in the DCLHb group with the greatest difference at POD 1 and 2. Postmortem analysis of the major organs did not show any sign of hemoglobin deposit in the DCLHb group. In the given setup DCLHb can be administered in a large quantity with good hematological tolerance and without any deposits in major organs. A prolonged plasma expander effect was observed.
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Report on a review of selected general and application controls over the Iowa Public Employees’ Retirement System I-Que Pension Administration System for the period June 18, 2012 through July 11, 2012