Griffith University

About: Griffith University is a education organization based out in Brisbane, Queensland, Australia. It is known for research contribution in the topics: Population & Poison control. The organization has 13830 authors who have published 49318 publications receiving 1420865 citations.

Postconditioning reduces infarct size via adenosine receptor activation by endogenous adenosine.

Abstract: Objective : This study tested the hypothesis that brief cycles of iterative ischemia–reperfusion at onset of reperfusion (termed “postconditioning”, post-con) delays washout of intravascular adenosine and thereby increases endogenous adenosine receptor (AR) activation during the early moments of reperfusion (R). Methods : Isolated mouse hearts were subjected to 20 min global ischemia (I) and 30 min R with or without post-con (3 or 6 cycles of 10 s RI post-con, three cycles of 10 s R followed by 10 s LCA re-occlusion immediately upon R. In the following interventions, drugs (or vehicle) were administered 5 min before R in the absence or presence (±) of post-con. Vehicle (DMSO <300 μl/kg); 8-SPT (non-selective AR antagonist, 10 mg/kg) ± post-con; DPCPX (A1AR antagonist, 0.1 mg/kg) ± post-con; ZM241385 (A2AAR antagonist, 0.2 mg/kg) ± post-con; MRS1523 (A3AR antagonist, 2 mg/kg) ± post-con. Results : In isolated mouse hearts, post-con reduced diastolic pressure during both early (26 ± 3* vs. 37 ± 3 mmHg at 5 min) and late (22 ± 3* vs. 34 ± 3 mmHg at 30 min) R. Post-con also hastened the early recovery of contractile function (developed pressure 39 ± 6* vs. 16 ± 2 mmHg at 5 min R), although differences did not persist at 30 min R. Importantly, post-con was associated with reduced adenosine washout (58 ± 5* vs. 155 ± 16 nM/min/g) at 2 min R suggesting greater retention time of intravascular adenosine. In rats, post-con significantly attenuated infarct size compared to control (40 ± 3% vs. 53 ± 2%* in control), an effect that was unaltered by DPCPX (42 ± 2%) but was abrogated by 8-SPT (50 ± 2%), ZM241385 (49 ± 3%) or MRS1523 (52 ± 1%) ( P <0.02). Conclusion : These data suggest that post-con involves endogenous activation of A2A and A3 but not A1AR subtypes. This activation may be linked to the delay in the washout of intravascular adenosine during the early minutes of R during which post-con is applied.

The Anti-Cancer Effect of Quercetin: Molecular Implications in Cancer Metabolism.

Abstract: Cancer is a problem with worldwide importance and is the second leading cause of death globally. Cancer cells reprogram their metabolism to support their uncontrolled expansion by increasing biomass (anabolic metabolism—glycolysis) at the expense of their energy (bioenergetics-mitochondrial function) requirements. In this aspect, metabolic reprogramming stands out as a key biological process in understanding the conversion of a normal cell into a neoplastic precursor. Quercetin is the major representative of the flavonoid subclass of flavonols. Quercetin is ubiquitously present in fruits and vegetables, being one of the most common dietary flavonols in the western diet. The anti-cancer effects of quercetin include its ability to promote the loss of cell viability, apoptosis and autophagy through the modulation of PI3K/Akt/mTOR, Wnt/β-catenin, and MAPK/ERK1/2 pathways. In this review, we discuss the role of quercetin in cancer metabolism, addressing specifically its ability to target molecular pathways involved in glucose metabolism and mitochondrial function.

New approaches narrow global species estimates for beetles, insects, and terrestrial arthropods

Abstract: It has been suggested that we do not know within an order of magnitude the number of all species on Earth [May RM (1988) Science 241(4872):1441–1449]. Roughly 1.5 million valid species of all organisms have been named and described [Costello MJ, Wilson S, Houlding B (2012) Syst Biol 61(5):871–883]. Given Kingdom Animalia numerically dominates this list and virtually all terrestrial vertebrates have been described, the question of how many terrestrial species exist is all but reduced to one of how many arthropod species there are. With beetles alone accounting for about 40% of all described arthropod species, the truly pertinent question is how many beetle species exist. Here we present four new and independent estimates of beetle species richness, which produce a mean estimate of 1.5 million beetle species. We argue that the surprisingly narrow range (0.9–2.1 million) of these four autonomous estimates—derived from host-specificity relationships, ratios with other taxa, plant:beetle ratios, and a completely novel body-size approach—represents a major advance in honing in on the richness of this most significant taxon, and is thus of considerable importance to the debate on how many species exist. Using analogous approaches, we also produce independent estimates for all insects, mean: 5.5 million species (range 2.6–7.8 million), and for terrestrial arthropods, mean: 6.8 million species (range 5.9–7.8 million), which suggest that estimates for the world’s insects and their relatives are narrowing considerably.