Innovative therapeutic approaches for the treatment of myocardial ischemia and angina

Cardiac energy metabolism is complex and has three main components: 1. Substrate utilisation, 2 Oxydative phosphorilation and 3. Transfer of high energy phosphates. Substrate utilization involves the cellular uptake of free fatty acids, glucose and amino acids, their breakdown by beta-oxidation and glycolysis, and the entry of Acetyl Coenzyme A into the Krebs cycle. Oxidative phosphorylation involves the production of energy by the mitochondrial respiratory chain and the production of high-energy phosphates. Until recent it was not known that it was possible to delimitate the infarct size through therapeutic interventions. Likely, the improvement to understand the mechanisms of cellular survivor occurs in that year, when Murry et al. discovered an intrinsic mechanism of myocardial protection, which they denominated as ischemic preconditioning. In that experiment, it was observed that four cycles of five minutes of ischemia, with intermittent reperfusion, before 40 min of ischemia period, resulted in reduction of 75% of the infarct size. Also, it was demonstrated by these researches that this protection it was not resulted by collateral overture and that protective effect of the ischemic preconditioning was abolished in the presence of prolonged ischemia, with duration of 3 h. Two phenomenons, the walk-through angina and the warm up phenomenon could represent a clinical manifestation of preconditioning. The phenomenon of walk-through angina was first related in the end of century XVIII in a patient that developed angina during the effort, but experimented the paradox disappearing of the pain with the exercise continuation. The exact molecular mechanisms involved in ischemic preconditioning are not fully elucidated. Therefore, due to the high prevalence of risk factors to cardiovascular diseases and the high morbidity and mortality associated with coronary artery disease, there is a needed to understand even better the cardiac metabolism during ischemia and the strategies to reduce the consequences of the ischemia, to preserve the viability of the ischemic myocardium

Hamilton-Jacobi Approach for First Order Actions and Theories with Higher Derivatives

In this work we analyze systems described by Lagrangians with higher order derivatives in the context of the Hamilton-Jacobi formalism for first order actions. Two different approaches are studied here: the first one is analogous to the description of theories with higher derivatives in the hamiltonian formalism according to [Sov. Phys. Journ. 26 (1983) 730; the second treats the case where degenerate coordinate are present, in an analogy to reference [Nucl. Phys. B 630 (2002) 509]. Several examples are analyzed where a comparison between both approaches is made

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset