903 resultados para dopaminergic agents


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Stimulation of erythropoiesis is one of the most efficient ways of doping. This type of doping is advantageous for aerobic physical exercise and of particular interest to endurance athletes. Erythropoiesis, which takes place in bone marrow, is under the control of EPO, a hormone secreted primarily by the kidneys when the arterial oxygen tension decreases. In certain pathological disorders, such as chronic renal failure, the production of EPO is insufficient and results in anemia. The pharmaceutical industry has, thus, been very interested in developing drugs that stimulate erythropoiesis. With this aim, various strategies have been, and continue to be, envisaged, giving rise to an expanding range of drugs that are good candidates for doping. Anti-doping control has had to deal with this situation by developing appropriate methods for their detection. This article presents an overview of both the drugs and the corresponding methods of detection, and thus follows a roughly chronological order.

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El document és el resultat d'una investigació més àmplia sobre la construcció de l'Arc Mediterrani. El seu objectiu és posar en relleu el notable grau de desenvolupament de la cooperació regional en la matèria, a través d'una anàlisi detallada de les diferents figures institucionalitzades de cooperació territorial existents (o haver existit) a la zona. L'anàlisi s'ha dut a terme des d'un punt de vista temàtic, basat en els objectius prioritaris d'aquestes institucions. En concret, les xifres estudiades es limiten a les institucions formals o les associacions de col · laboració de caràcter específic, com ara euroregions o les agrupacions europees d'interès econòmic, entès com les figures de major institucionalització dels espais transnacionals a nivell europeu. En canvi, hem deixat de banda altres figures, com Interreg (finançat pel FEDER), ja que no són entitats correctament. Encara que de vegades els acords de cooperació establerts per als projectes d'Interreg han donat lloc a algunes de les entitats estudiades aquí.

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Oleoylethanolamide (OEA) is an agonist of the peroxisome proliferator-activated receptor α (PPARα) and has been described to exhibit neuroprotective properties when administered locally in animal models of several neurological disorder models, including stroke and Parkinson's disease. However, there is little information regarding the effectiveness of systemic administration of OEA on Parkinson's disease. In the present study, OEA-mediated neuroprotection has been tested on in vivo and in vitro models of 6-hydroxydopamine (6-OH-DA)-induced degeneration. The in vivo model was based on the intrastriatal infusion of the neurotoxin 6-OH-DA, which generates Parkinsonian symptoms. Rats were treated 2 h before and after the 6-OH-DA treatment with systemic OEA (0.5, 1, and 5 mg/kg). The Parkinsonian symptoms were evaluated at 1 and 4 wk after the development of lesions. The functional status of the nigrostriatal system was studied through tyrosine-hydroxylase (TH) and hemeoxygenase-1 (HO-1, oxidation marker) immunostaining as well as by monitoring the synaptophysin content. In vitro cell cultures were also treated with OEA and 6-OH-DA. As expected, our results revealed 6-OH-DA induced neurotoxicity and behavioural deficits; however, these alterations were less severe in the animals treated with the highest dose of OEA (5 mg/kg). 6-OH-DA administration significantly reduced the striatal TH-immunoreactivity (ir) density, synaptophysin expression, and the number of nigral TH-ir neurons. Moreover, 6-OH-DA enhanced striatal HO-1 content, which was blocked by OEA (5 mg/kg). In vitro, 0.5 and 1 μM of OEA exerted significant neuroprotection on cultured nigral neurons. These effects were abolished after blocking PPARα with the selective antagonist GW6471. In conclusion, systemic OEA protects the nigrostriatal circuit from 6-OH-DA-induced neurotoxicity through a PPARα-dependent mechanism.

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The administration of selective serotonin reuptake inhibitors (SSRIs) typically used as antidepressants increases alcohol consumption after an alcohol deprivation period in rats. However, the appearance of this effect after the treatment with selective noradrenaline reuptake inhibitors (SNRIs) has not been studied. In the present work we examined the effects of a 15-d treatment with the SNRI atomoxetine (1, 3 and 10 mg/kg, i.p.) in male rats trained to drink alcohol solutions in a 4-bottle choice test. The treatment with atomoxetine (10 mg/kg, i.p.) during an alcohol deprivation period increased alcohol consumption after relapse. This effect only lasted one week, disappearing thereafter. Treatment with atomoxetine did not cause a behavioral sensitized response to a challenge dose of amphetamine (1.5 mg/kg, i.p.), indicating the absence of a supersensitive dopaminergic transmission. This effect is markedly different from that of SSRI antidepressants that produced both long-lasting increases in alcohol consumption and behavioral sensitization. Clinical implications are discussed.

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Mycobacterium tuberculosis (Mtb) has acquired resistance and consequently the antibiotic therapeutic options available against this microorganism are limited. In this scenario, the use of usnic acid (UA), a natural compound, encapsulated into liposomes is proposed as a new approach in multidrug-resistant tuberculosis (MDR-TB) therapy. Thus the aim of this study was to evaluate the effect of the encapsulation of UA into liposomes, as well as its combination with antituberculous agents such as rifampicin (RIF) and isoniazid (INH) against MDR-TB clinical isolates. The in vitro antimycobacterial activity of UA-loaded liposomes (UA-Lipo) against MDR-TB was assessed by the microdilution method. The in vitro interaction of UA with antituberculous agents was carried out using checkerboard method. Minimal inhibitory concentration values were 31.25 and 0.98 µg/mL for UA and UA-Lipo, respectively. The results exhibited a synergistic interaction between RIF and UA [fractional inhibitory concentration index (FICI) = 0.31] or UA-Lipo (FICI = 0.28). Regarding INH, the combination of UA or UA-Lipo revealed no marked effect (FICI = 1.30-2.50). The UA-Lipo may be used as a dosage form to improve the antimycobacterial activity of RIF, a first-line drug for the treatment of infections caused by Mtb.

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During its life cycle Leishmania spp. face several stress conditions that can cause DNA damages. Base Excision Repair plays an important role in DNA maintenance and it is one of the most conserved mechanisms in all living organisms. DNA repair in trypanosomatids has been reported only for Old World Leishmania species. Here the AP endonuclease from Leishmania (L.) amazonensis was cloned, expressed in Escherichia coli mutants defective on the DNA repair machinery, that were submitted to different stress conditions, showing ability to survive in comparison to the triple null mutant parental strain BW535. Phylogenetic and multiple sequence analyses also confirmed that LAMAP belongs to the AP endonuclease class of proteins.

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Since the beginning of the 1990's, a dozen of new anti-epileptic drugs have been on the market or will be soon. This article reviews the daily clinical utilisation of new anti-epileptic drugs. It considers, without being complete, the current opinions and tendencies. The new anti-epileptic substances are generally as efficient as conventional medications. However, they are better tolerated and are more easily used in combination with conventional anti-epileptic drugs. Polytherapy is certainly the form of treatment, which is used in the most cases of resistant epilepsies. The surgical treatment can be used in only a very limited number of cases. The objective of treatment is the complete control of seizures, with minimum secondary effects. Though this objective is rarely reached, the NAE significantly improves the quality of life of patients suffering from severe epilepsy. The utilisation of NAE is not without risk. Increase in the frequency and severity of seizures may occur; we should remember that severe adverse effects appeared in the post-marketing period of the use of Vigabatrine and Felbamate. Therefore, we must remain vigilant in the clinical use of the anti-epileptic drugs.

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This study evaluated the efficacy of lactic acid bacteria (LAB) isolated from fresh fruits and vegetables as biocontrol agents against the phytopathogenic and spoilage bacteria and fungi, Xanthomonas campestris, Erwinia carotovora, Penicillium expansum, Monilinia laxa, and Botrytis cinerea. The antagonistic activity of 496 LAB strains was tested in vitro and all tested microorganisms except P. expansum were inhibited by at least one isolate. The 496 isolates were also analyzed for the inhibition of P. expansum infection in wounds of Golden Delicious apples. Four strains (TC97, AC318, TM319, and FF441) reduced the fungal rot diameter of the apples by 20%; only Weissella cibaria strain TM128 decreased infection levels by 50%. Cell-free supernatants of selected antagonistic bacteria were studied to determine the nature of the antimicrobial compounds produced. Organic acids were the preferred mediators of inhibition but hydrogen peroxide was also detected when strains BC48, TM128, PM141 and FF441 were tested against E. carotovora. While previous reports of antifungal activity by LAB are scarce, our results support the potential of LAB as biocontrol agents against postharvest rot. [Int Microbiol 2008; 11(4):231-236]

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BACKGROUND: Infective endocarditis (IE) mostly occurs after spontaneous low-grade bacteremia. Thus, IE cannot be prevented by circumstantial antibiotic prophylaxis. Platelet activation following bacterial-fibrinogen interaction or thrombin-mediated fibrinogen-fibrin polymerization is a critical step in vegetation formation. We tested the efficacy of antiplatelet and antithrombin to prevent experimental IE. METHODS: A rat model of experimental IE following prolonged low-grade bacteremia mimicking smoldering bacteremia in humans was used. Prophylaxis with antiplatelets (aspirin, ticlopidine [alone or in combination], eptifibatide, or abciximab) or anticoagulants (antithrombin dabigatran etexilate or anti-vitamin K acenocoumarol) was started 2 days before inoculation with Streptococcus gordonii or Staphylococcus aureus. Valve infection was assessed 24 hours later. RESULTS: Aspirin plus ticlopidine, as well as abciximab, protected 45%-88% of animals against S. gordonii and S. aureus IE (P < .05). Dabigatran etexilate protected 75% of rats against IE due to S. aureus (P < .005) but failed to protect against S. gordonii (<30% protection). Acenocoumarol was ineffective. CONCLUSIONS: Antiplatelet and direct antithrombin agents may be useful in the prophylaxis of IE in humans. In particular, the potential dual benefit of dabigatran etexilate might be reconsidered for patients with prosthetic valves, who require life-long anticoagulation and in whom S. aureus IE is associated with high mortality.

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El present treball estudiarà la comunitat d’espècies Coleoptera d’un camp de cítrics situat a la Selva de Camp, Tarragona, durant el període de temps dels anys 2002 fins al 2011. Els Coleoptera és l’ordre animal conegut comunament com els “escarabats” i és el més abundant i variat de tot el regne animal. Els estudis realitzats són pocs i, normalment, de les espècies més abundants (sobretot la família Coccinellidae). Totes les espècies d’aquest ordre presenten unes característiques típiques (García et al., 1989). (1) Presenten una cutícula dura, rígida i quitinitzada, amb el primer parell d’ales endurides (èlitres). Gran protecció als traumes físics. (2) Tenen una gran capacitat per retenir la humitat degut a que els estigmes s’obren els èlitres i eviten la pèrdua d’aigua per transpiració. (3) Presenten mandíbules mastegadores, adaptables i utilitzables per a una gran varietat de funcions (Chinery, 1988). (4) Algunes espècies poden acumular substàncies tòxiques a l’organisme. Presenten un règim alimentari fitòfag o micòfag, per norma general, tot i que també es poden trobar espècies sapròfagues o depredadores. És per aquest motiu que les espècies de Coleoptera podrien presentar un paper important com a potencial plagues o com a possible control biològic (Zahradnik, 1990). Durant moltes dècades, els plaguicides han constituït una lluita química contra les plagues dels cultius agrícoles, obtenint molt bons resultats en quant a manteniment i qualitat de les collites. No obstant, la seva utilització deliberada ha constituït en molts casos una important font de contaminació del territori. La seva gran mobilitat i persistència ha originat efectes de bioacumulació i biomagnificació a les xarxes tròfiques dels essers vius presents en aquestes zones. Actualment, per evitar tots aquests problemes ocasionats pels productes sintètics, el control biològic de plagues constitueix un dels principals pilars de la protecció moderna de cultius (Jacas et al., 2005). Se sap que les formigues tenen un doble rol molt important a les comunitats vegetals (poden ser mutualistes o depredadors generalistes), fent que la presència o absència d’aquestes pugui tenir efectes potencials sobre l’abundància d’altres artròpodes (James et al., 1999). És per aquest motiu que al present treball es realitzen experiments amb dos tipus d’arbres, els que presenten formigues i els que les formigues s’han exclòs experimentalment. Així doncs, els objectius del present treball són: - Descriure quantitativament la Comunitat de Coleoptera no Coccinellidae. - Descriure els canvis que s’han produït en la comunitat de Coleoptera al llarg de 10 anys. - Valorar la importància de les diferents espècies i/o famílies com a components de la biodiversitat d’un conreu ecològic. - Descriure els efectes sobre la comunitat de Coleoptera no Coccinellidae de la presència o absència de formgiues. - Valorar la importància de les diferents espècies i/o famílies com a possibles plagues o com a agents de control biològic.

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Review of the book: The Tinkerer's Accomplice: How Design Emerges From Life Itself by J. Scott TurnerHarvard University Press: 2007. 304 pp.