1,530 research outputs found
Espaço e economia no Sistema de Cantillon [Space and economics in the Cantillon's system]
The paper outlines the economic geography underlying the Essay on the nature of commerce in general, and discusses the extent to which it relates to the theoretical arguments within Cantillon's system. The main conclusions are: a) Cantillon's social structure scheme presents a first draft of urban networks, ranked according to the economic and non-economic decisions of the property owners; b) transportation costs are a central element of the Essay's monetary theory and of its price making model; and c) transportation costs affect the specie flow mechanism, which governs international trade. In spite of the Essay's advanced approach to the market and money circulation processes, Cantillon's locational analysis is in many aspects limited by an agricultural and naturalist vision of the economic system.Cantillon, location, space, economic geography
Barbon versus Locke sobre o valor da moeda
The paper contrasts Nicholas Barbon's and John Locke's positions, in the 1690's English monetary debates about raising the money. Although Barbon's and Locke's arguments were referred to the English monetary setting of the 1690's, it can be argued that the issues pointed at and the theoretical achievements of the debates were instrumental to the constitution of monetary economics and of economic theory itself, a process unfolded in the late seventeenth century and eighteenth century. Locke's theory, in special, stood as a benchmark to monetary theory for a 150 years long period. The text follows Barbon's review of Locke's position on monetary issues, and tries to make an assessment of both authors contributions to monetary economics.O artigo discute as posições contrastantes de Nicholas Barbon e John Locke no debate monetário inglês sobre a "valorização do dinheiro" dos anos 1690. Embora referidos às condições do sistema monetário inglês da época, os temas e argumentos do debate foram fundamentais na formação da teoria monetária e da teoria econômica, entre o final do século XVII e o século XVIII. O artigo acompanha a crítica de Barbon a Locke, e procura efetuar um sumário da teoria monetária de Locke, cuja importância no debate econômico se estendeu por 150 anos
Antimalarial Activity of Potential Inhibitors of Plasmodium falciparum Lactate Dehydrogenase Enzyme Selected by Docking Studies
The Plasmodium falciparum lactate dehydrogenase enzyme (PfLDH) has been considered as a potential molecular target for antimalarials due to this parasite's dependence on glycolysis for energy production. Because the LDH enzymes found in P. vivax, P. malariae and P. ovale (pLDH) all exhibit ∼90% identity to PfLDH, it would be desirable to have new anti-pLDH drugs, particularly ones that are effective against P. falciparum, the most virulent species of human malaria. Our present work used docking studies to select potential inhibitors of pLDH, which were then tested for antimalarial activity against P. falciparum in vitro and P. berghei malaria in mice. A virtual screening in DrugBank for analogs of NADH (an essential cofactor to pLDH) and computational studies were undertaken, and the potential binding of the selected compounds to the PfLDH active site was analyzed using Molegro Virtual Docker software. Fifty compounds were selected based on their similarity to NADH. The compounds with the best binding energies (itraconazole, atorvastatin and posaconazole) were tested against P. falciparum chloroquine-resistant blood parasites. All three compounds proved to be active in two immunoenzymatic assays performed in parallel using monoclonals specific to PfLDH or a histidine rich protein (HRP2). The IC50 values for each drug in both tests were similar, were lowest for posaconazole (<5 µM) and were 40- and 100-fold less active than chloroquine. The compounds reduced P. berghei parasitemia in treated mice, in comparison to untreated controls; itraconazole was the least active compound. The results of these activity trials confirmed that molecular docking studies are an important strategy for discovering new antimalarial drugs. This approach is more practical and less expensive than discovering novel compounds that require studies on human toxicology, since these compounds are already commercially available and thus approved for human use
Transforming Growth Factor Beta 2 and Heme Oxygenase 1 Genes Are Risk Factors for the Cerebral Malaria Syndrome in Angolan Children
BACKGROUND: Cerebral malaria (CM) represents a severe outcome of the Plasmodium falciparum infection. Recent genetic studies have correlated human genes with severe malaria susceptibility, but there is little data on genetic variants that increase the risk of developing specific malaria clinical complications. Nevertheless, susceptibility to experimental CM in the mouse has been linked to host genes including Transforming Growth Factor Beta 2 (TGFB2) and Heme oxygenase-1 (HMOX1). Here, we tested whether those genes were governing the risk of progressing to CM in patients with severe malaria syndromes. METHODOLOGY/PRINCIPAL FINDINGS: We report that the clinical outcome of P. falciparum infection in a cohort of Angolan children (n = 430) correlated with nine TGFB2 SNPs that modify the risk of progression to CM as compared to other severe forms of malaria. This genetic effect was explained by two haplotypes harboring the CM-associated SNPs (Pcorrec. = 0.035 and 0.036). In addition, one HMOX1 haplotype composed of five CM-associated SNPs increased the risk of developing the CM syndrome (Pcorrec. = 0.002) and was under-transmitted to children with uncomplicated malaria (P = 0.036). Notably, the HMOX1-associated haplotype conferred increased HMOX1 mRNA expression in peripheral blood cells of CM patients (P = 0.012). CONCLUSIONS/SIGNIFICANCE: These results represent the first report on CM genetic risk factors in Angolan children and suggest the novel hypothesis that genetic variants of the TGFB2 and HMOX1 genes may contribute to confer a specific risk of developing the CM syndrome in patients with severe P. falciparum malaria. This work may provide motivation for future studies aiming to replicate our findings in larger populations and to confirm a role for these genes in determining the clinical course of malaria
Overactive bladder – 18 years – part I
ABSTRACT Traditionally, the treatment of overactive bladder syndrome has been based on the use of oral medications with the purpose of reestablishing the detrusor stability. The recent better understanding of the urothelial physiology fostered conceptual changes, and the oral anticholinergics – pillars of the overactive bladder pharmacotherapy – started to be not only recognized for their properties of inhibiting the detrusor contractile activity, but also their action on the bladder afference, and therefore, on the reduction of the symptoms that constitute the syndrome. Beta-adrenergic agonists, which were recently added to the list of drugs for the treatment of overactive bladder, still wait for a definitive positioning – as either a second-line therapy or an adjuvant to oral anticholinergics. Conservative treatment failure, whether due to unsatisfactory results or the presence of adverse side effects, define it as refractory overactive bladder. In this context, the intravesical injection of botulinum toxin type A emerged as an effective option for the existing gap between the primary measures and more complex procedures such as bladder augmentation. Sacral neuromodulation, described three decades ago, had its indication reinforced in this overactive bladder era. Likewise, the electric stimulation of the tibial nerve is now a minimally invasive alternative to treat those with refractory overactive bladder. The results of the systematic literature review on the oral pharmacological treatment and the treatment of refractory overactive bladder gave rise to this second part of the review article Overactive Bladder – 18 years, prepared during the 1st Latin-American Consultation on Overactive Bladder
Overactive bladder – 18 years – Part II
ABSTRACT Traditionally, the treatment of overactive bladder syndrome has been based on the use of oral medications with the purpose of reestablishing the detrusor stability. The recent better understanding of the urothelial physiology fostered conceptual changes, and the oral anticholinergics – pillars of the overactive bladder pharmacotherapy – started to be not only recognized for their properties of inhibiting the detrusor contractile activity, but also their action on the bladder afference, and therefore, on the reduction of the symptoms that constitute the syndrome. Beta-adrenergic agonists, which were recently added to the list of drugs for the treatment of overactive bladder, still wait for a definitive positioning – as either a second-line therapy or an adjuvant to oral anticholinergics. Conservative treatment failure, whether due to unsatisfactory results or the presence of adverse side effects, define it as refractory overactive bladder. In this context, the intravesical injection of botulinum toxin type A emerged as an effective option for the existing gap between the primary measures and more complex procedures such as bladder augmentation. Sacral neuromodulation, described three decades ago, had its indication reinforced in this overactive bladder era. Likewise, the electric stimulation of the tibial nerve is now a minimally invasive alternative to treat those with refractory overactive bladder. The results of the systematic literature review on the oral pharmacological treatment and the treatment of refractory overactive bladder gave rise to this second part of the review article Overactive Bladder – 18 years, prepared during the 1st Latin-American Consultation on Overactive Bladder
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