Differential Pulmonary Effects of CoO and La2O3 Metal Oxide Nanoparticle Responses During Aerosolized Inhalation in Mice

Background: Although classified as metal oxides, cobalt monoxide (CoO) and lanthanum oxide (La2O3) nanoparticles, as representative transition and rare earth oxides, exhibit distinct material properties that may result in different hazardous potential in the lung. The current study was undertaken to compare the pulmonary effects of aerosolized whole body inhalation of these nanoparticles in mice. Results: Mice were exposed to filtered air (control) and 10 or 30 mg/m3 of each particle type for 4 days and then examined at 1 h, 1, 7 and 56 days post-exposure. The whole lung burden 1 h after the 4 day inhalation of CoO nanoparticles was 25 % of that for La2O3 nanoparticles. At 56 days post exposure, \u3c 1 % of CoO nanoparticles remained in the lungs; however, 22–50 % of the La2O3 nanoparticles lung burden 1 h post exposure was retained at 56 days post exposure for low and high exposures. Significant accumulation of La2O3 nanoparticles in the tracheobronchial lymph nodes was noted at 56 days post exposure. When exposed to phagolysosomal simulated fluid, La nanoparticles formed urchin-shaped LaPO4 structures, suggesting that retention of this rare earth oxide nanoparticle may be due to complexation of cellular phosphates within lysosomes. CoO nanoparticles caused greater lactate dehydrogenase release in the bronchoalveolar fluid (BALF) compared to La2O3 nanoparticles at 1 day post exposure, while BAL cell differentials indicate that La2O3 nanoparticles generated more inflammatory cell infiltration at all doses and exposure points. Histopathological analysis showed acute inflammatory changes at 1 day after inhalation of either CoO or La2O3 nanoparticles. Only the 30 mg/m3 La2O3 nanoparticles exposure caused chronic inflammatory changes and minimal fibrosis at day 56 post exposure. This is in agreement with activation of the NRLP3 inflammasome after in vitro exposure of differentiated THP-1 macrophages to La2O3 but not after CoO nanoparticles exposure. Conclusion: Taken together, the inhalation studies confirmed the trend of our previous sub-acute aspiration study, which reported that CoO nanoparticles induced more acute pulmonary toxicity, while La2O3 nanoparticles caused chronic inflammatory changes and minimal fibrosis

Infographic. Clinical recommendations for return to play during the COVID-19 pandemic

COVID-19 AND RETURN TO PLAY The world of sport has recently returned to training and competition following suspension due to the COVID-19 pandemic. It is concerning that a number of athletes have tested positive for COVID-19 after returning to competition. 1 Numerous authors have attempted to address return to play given the importance and complexity of the issue, with notable attention on possible cardiac implications.2–6 SCOPE OF THE INFOGRAPHIC The specific recommendations shown in the present infographic (figure 1) have been generated by a panel of international experts and represent a compilation of the numerous approaches used to inform resumption of regular sports during the COVID-19 pandemic. Despite the different regulations around the world and the particular characteristics of each sport, it is essential to provide informative, consistent and specific guidance for safe return to training and competition at this most difficult time. ..

Recommendations for return to sport during the SARS-CoV-2 pandemic

In this viewpoint we make specific recommendations that can assist and make the return to sport/exercise as safe as possible for all those impacted - from the recreational athlete to the elite athlete. We acknowledge that there are varying rules and regulations around the world, not to mention the varying philosophies and numerous schools of thought as it relates to return to sport/exercise and we have been cognisant of this in our recommendations. Despite the varying rules and circumstances around the world, we believe it is essential to provide some helpful and consistent guidance for return to training and sport for sport and exercise physicians around the world at this most difficult time. The present viewpoint provides practical and medical recommendations on the resumption to sport process

Recommendations for return to sport during the SARS-CoV-2 pandemic

In this viewpoint we make specific recommendations that can assist and make the return to sport/exercise as safe as possible for all those impacted - from the recreational athlete to the elite athlete. We acknowledge that there are varying rules and regulations around the world, not to mention the varying philosophies and numerous schools of thought as it relates to return to sport/exercise and we have been cognisant of this in our recommendations. Despite the varying rules and circumstances around the world, we believe it is essential to provide some helpful and consistent guidance for return to training and sport for sport and exercise physicians around the world at this most difficult time. The present viewpoint provides practical and medical recommendations on the resumption to sport process.</p

Neptune Odyssey: A Flagship Concept for the Exploration of the Neptune–Triton System

The Neptune Odyssey mission concept is a Flagship-class orbiter and atmospheric probe to the Neptune-Triton system. This bold mission of exploration would orbit an ice-giant planet to study the planet, its rings, small satellites, space environment, and the planet-sized moon Triton. Triton is a captured dwarf planet from the Kuiper Belt, twin of Pluto, and likely ocean world. Odyssey addresses Neptune system-level science, with equal priorities placed on Neptune, its rings, moons, space environment, and Triton. Between Uranus and Neptune, the latter is unique in providing simultaneous access to both an ice giant and a Kuiper Belt dwarf planet. The spacecraft - in a class equivalent to the NASA/ESA/ASI Cassini spacecraft - would launch by 2031 on a Space Launch System or equivalent launch vehicle and utilize a Jupiter gravity assist for a 12 yr cruise to Neptune and a 4 yr prime orbital mission; alternatively a launch after 2031 would have a 16 yr direct-to-Neptune cruise phase. Our solution provides annual launch opportunities and allows for an easy upgrade to the shorter (12 yr) cruise. Odyssey would orbit Neptune retrograde (prograde with respect to Triton), using the moon's gravity to shape the orbital tour and allow coverage of Triton, Neptune, and the space environment. The atmospheric entry probe would descend in ~37 minutes to the 10 bar pressure level in Neptune's atmosphere just before Odyssey's orbit-insertion engine burn. Odyssey's mission would end by conducting a Cassini-like "Grand Finale,"passing inside the rings and ultimately taking a final great plunge into Neptune's atmosphere

The Effects of Group II Metabotropic Glutamate Receptor Antagonism on Delayed Non-match to Odor Performance in Male Long-Evans Rats

In recent years, there has been an increased interest in the role of glutamate, the brain’s major excitatory neurotransmitter, in MDD. There is ample evidence that glutamate dysfunction is present in patients with varying degrees of depression. With this mechanistic shift behind MDD has come a better understanding of the importance of cognitive dysfunction in depressed patients. The general view of MDD was that it was a mood disorder, however recent evidence suggests that cognitive functioning is also critical to relief of depressive symptomology. Attempts have been made to modulate excitatory neural networks using a class of glutamate receptors known as ionotropic glutamate receptors (iGlu receptors). However, drugs which act on iGlu receptors lead to harmful exocitoxic effects and cognitive dysfunctions. Another subtype of glutamate receptor known as metabotropic glutamate receptors (mGlu receptors) may play a more modulatory role in excitatory neurotransmission. In the present study we investigated the role of the mGlu 2/3 receptor subtypes in cognitive function in Long Evans rats using a modified version of the delayed-nonmatch-to-sample task (DNMS). We made two hypotheses, 1) that the DNMS is a working memory task, in which accuracy decreases with increasing inter-trial intervals (ITI), 2) that antagonism of mGlu 2/3 receptors using LY341495 would improve working memory performance on the DNMS task. In congruence with our first hypothesis, performance on the DNMS task is decreased with increasing ITIs. However, LY341495 administration (30 min IP) impaired DNMS accuracy at 3 mg/kg and increased response latencies at 1 and 3 mg/kg. Therefore, it appears that increasing neuronal glutamate is not sufficient to improve cognitive functions such as working memory in normal subjects. Future studies may want to investigate the effects of LY341495 using a biological model of depression like the chronic corticosterone model

Superior Categorical and Coordinate Spatial Task Performance in Inconsistent-Handers Relative to Consistent-Right-Handers

Categorical versus coordinate spatial tasks rely differentially on the left versus right hemisphere. Given the neuroanatomical and neurophysiological differences between inconsistent- versus consistent-right-handers (ICH versus CRH, respectively), such that the former demonstrates increased access to right hemisphere processes relative to the latter, it was hypothesized that ICH would outperform CRH on a test of coordinate spatial knowledge. Previous work demonstrating reliance on the right hemisphere for both categorical and coordinate information in non-right-handers using lateralized stimuli of brief duration suggested ICH might also outperform CRH on a categorical task as well. Participants navigated a virtual environment, landmark-to-landmark, within a 3-dimensional first-person point of view with high ecological validity, and then were tested on either their categorical or coordinate spatial knowledge. ICH were superior relative to the CRH on both types of spatial knowledge. Additionally, ICH navigated the environment during learning more quickly, and reported being more confident in their knowledge of the location of landmarks within the environment, compared with CRH. Results are discussed in terms of potential handedness differences in spatial ability generally

Lactobacilli Modulate Epithelial Cytoprotection through the Nrf2 Pathway

SummaryAn optimal gut microbiota influences many beneficial processes in the metazoan host. However, the molecular mechanisms that mediate and function in symbiont-induced host responses have not yet been fully characterized. Here, we report that cellular ROS enzymatically generated in response to contact with lactobacilli in both mice and Drosophila has salutary effects against exogenous insults to the intestinal epithelium via the activation of Nrf2 responsive cytoprotective genes. These data show that the xenobiotic-inducible Nrf2 pathway participates as a signaling conduit between the prokaryotic symbiont and the eukaryotic host. Indeed, our data imply that the capacity of lactobacilli to induce redox signaling in epithelial cells is a highly conserved hormetic adaptation to impel cellular conditioning to exogenous biotic stimuli. These data also highlight the role the microbiota plays in eukaryotic cytoprotective pathways and may have significant implications in the characterization of a eubiotic microbiota