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Adaptive cardioprotective signalling is triggered by reactive oxygen species from NADPH oxidase, and leads to improved glutathione replenishment through redox-dependent modifications in GR.

Quick LinksAddThe recent discovery of the soybean aphid, Aphis glycines Matsamura, in the North Central region of the United States is significant because it is the first time that a soybeancolonizing aphid has been detected in the New World. Although the aphid has the potential to cause physiological loss of up to 52% on soybeans (4), it can also transmit Soybean mosaic virus (SMV). Transmission of Alfalfa mosaic virus (AMV) has not been reported. SMV, and less commonly AMV, are found in soybeans in the North Central states and are transmitted by numerous aphids in a nonpersistent manner (2; Grau, unpublished). For SMV, potential exists for specificity of transmission between virus strain and aphid species (3).For these reasons, it was important to determine if an endemic isolate of these viruses could be transmitted by this introduced species of aphid in the North Central region.Transmission experiments were conducted as described (3), using 3, 5, and 10 aphids per

Consequences of oxidative stress may be beneficial or detrimental in physiological systems. An organ system's position on the “hormetic curve” is governed by the source and temporality of reactive oxygen species (ROS) production, proximity of ROS to moieties most susceptible to damage, and the capacity of the endogenous cellular ROS scavenging mechanisms. Most importantly, the resilience of the tissue (the capacity to recover from damage) is a decisive factor, and this is reflected in the disparate response to ROS in cardiac and skeletal muscle. In myocytes, a high oxidative capacity invariably results in a significant ROS burden which in homeostasis, is rapidly neutralized by the robust antioxidant network. The up-regulation of key pathways in the antioxidant network is a central component of the hormetic response to ROS. Despite such adaptations, persistent oxidative stress over an extended time-frame (e.g., months to years) inevitably leads to cumulative damages, maladaptation and ultimately the pathogenesis of chronic diseases. Indeed, persistent oxidative stress in heart and skeletal muscle has been repeatedly demonstrated to have causal roles in the etiology of heart disease and insulin resistance, respectively. Deciphering the mechanisms that underlie the divergence between adaptive and maladaptive responses to oxidative stress remains an active area of research for basic scientists and clinicians alike, as this would undoubtedly lead to novel therapeutic approaches. Here, we provide an overview of major types of ROS in striated muscle and the divergent adaptations that occur in response to them. Emphasis is placed on highlighting newly uncovered areas of research on this topic, with particular focus on the mitochondria, and the diverging roles that ROS play in muscle health (e.g., exercise or preconditioning) and disease (e.g., cardiomyopathy, ischemia, metabolic syndrome).

Background: Vaccination and importation of dogs and cats are prohibited in the Galapagos, resulting in a uniquely isolated population. The purpose of this study was to determine the prevalence of infectious diseases of dogs and cats that impact their health, could spill over to native wildlife, or sentinel diseases of concern to humans.Hypothesis: The isolation of dogs and cats in the Galapagos protects them from diseases common in mainland populations. Animals: Ninety-five dogs and 52 cats presented during a neutering campaign. Methods: A prospective cross-sectional study was performed. Blood was collected for serological and DNA evaluation of a panel of infectious diseases.Results: Antibodies against parvovirus (100%), parainfluenza virus (100%), adenovirus 1/2 (66-67%), and distemper virus (22%) were present in dogs. Dirofilaria immitis was also common in dogs (34%), with lower prevalences of Wolbachia pipiens (22%), Bartonella sp. (13%), Ehrlichia/Anaplasma spp. (1%), and Mycoplasma haemocanis (1%) observed. Antibodies against panleukopenia virus (67%), Toxoplasma gondii (63%), calicivirus (44%), and herpesvirus 1 (10%) were detected in cats. Feline leukemia virus antigen, feline immunodeficiency virus antibody, or coronavirus antibodies were not detected. Bartonella sp. (44%) infections were common in cats, but only one was infected with M. haemofelis.Conclusions and Clinical Importance: Despite their relative seclusion from the rest of the world, cats and dogs of Isabela were exposed to many pathogens found in mainland South America. Parasite prophylaxis, neutering, and strict enforcement of animal movement restrictions would control a majority of the diseases. In the absence of vaccination, a reservoir of susceptible animals remains vulnerable to new disease introductions.

Arenaviridae are a family of single stranded RNA viruses of mammals and boid snakes. Twenty-nine distinct mammalian arenaviruses have been identified, many of which cause severe hemorrhagic disease in humans, particularly in parts of sub-Saharan Africa, and in Central and South America. Humans typically become infected with an arenavirus through contact with excreta from infected rodents. Tacaribe virus (TCRV) is an arenavirus that was first isolated from bats and mosquitoes during a rabies surveillance survey conducted in Trinidad from 1956 to 1958. Tacaribe virus is unusual because it has never been associated with a rodent host and since that one time isolation, the virus has not been isolated from any vertebrate or invertebrate hosts. We report the re-isolation of the virus from a pool of 100 host-seeking Amblyomma americanum (lone star ticks) collected in a Florida state park in 2012. TCRV was isolated in two cell lines and its complete genome was sequenced. The tick-derived isolate is nearly identical to the only remaining isolate from Trinidad (TRVL-11573), with 99.6% nucleotide identity across the genome. A quantitative RT-PCR assay was developed to test for viral RNA in host-seeking ticks collected from 3 Florida state parks. Virus RNA was detected in 56/500 (11.2%) of surveyed ticks. As this virus was isolated from ticks that parasitize humans, the ability of the tick to transmit the virus to people should be evaluated. Furthermore, reservoir hosts for the virus need to be identified in order to develop risk assessment models of human infection.

Critical limb ischemia is a devastating manifestation of peripheral arterial disease with no effective strategies for improving morbidity and mortality outcomes. We tested the hypothesis that cellular mitochondrial function is a key component of limb pathology and that improving mitochondrial function represents a novel paradigm for therapy. BALB/c mice were treated with a therapeutic mitochondrial-targeting peptide (MTP-131) and subjected to limb ischemia (HLI). Compared to vehicle control, MTP-131 rescued limb muscle capillary density and blood flow (64.7±11% of contralateral vs. 39.9±4%), and improved muscle regeneration. MTP-131 also increased electron transport system flux across all conditions at HLI day-7. In vitro, primary muscle cells exposed to experimental ischemia demonstrated markedly reduced (~75%) cellular respiration, which was rescued by MTP-131 during a recovery period. Compared to muscle cells, endothelial cell (HUVEC) respiration was inherently protected from ischemia (~30% reduction), but was also enhanced by MTP-131. These findings demonstrate an important link between ischemic tissue bioenergetics and limb blood flow and indicate that the mitochondria may be a pharmaceutical target for therapeutic intervention during critical limb ischemia.

Background:We have recently noted an acute increase in circulating free fatty acids and glycerol, as well as resting metabolic rate, when men and women ingested the dietary supplement OxyELITE Pro™ in a single dose. We have also noted a reduction in appetite when subjects were treated with this supplement for 14 consecutive days. It is possible that such findings may favor body weight and fat loss over time. Therefore, the purpose of the present study was to determine the effects of this dietary supplement on weight loss and associated markers using an eight week intervention.Methods:Exercise-trained subjects were randomly assigned in double blind manner to ingest either the dietary supplement (n = 16; aged 22.8 ± 0.7) or a placebo (n = 16; 22.5 ± 0.5) every day for eight weeks. Body weight, body composition, skinfold thickness, serum lipids, and appetite were measured as the primary outcome variables. As measures of supplement safety, a complete blood count and comprehensive metabolic panel were performed, and resting heart rate and blood pressure were measured (pre and post intervention).Results:No interactions or main effects were noted for our primary outcome measures (P > 0.05). However, when comparing pre and post intervention values for the supplement, significant decreases were noted in appetite, body weight, body fat percentage, and skinfold thickness (P < 0.05), while increases were noted for total and HDL-C, as well as for resting heart rate (P < 0.05). No changes were noted for placebo from pre to post intervention (P > 0.05), with the exception of an increase in HDL-C (P < 0.05). Blood pressure and bloodborne safety variables were not differently impacted by supplement or placebo (P > 0.05), with the exception of monocytes, for which an interaction effect was noted (P = 0.04).Conclusion:These data indicate that the dietary supplement OxyELITE Pro™ may assist in weight and body fat loss in a sample of exercise-trained men and women. The supplement does not result in any adverse effects pertaining to resting blood pressure or bloodborne markers of safety; however a small increase in resting heart rate is observed.