Adaptation of a mouse Doppler echocardiograph system for assessing cardiac function and thermal performance in a juvenile salmonid

Measures of cardiac performance are pertinent to the study of thermal physiology and exercise in teleosts, particularly as they pertain to migration success. Increased heart rate, stroke volume and cardiac output have previously been linked to improved swimming performance and increased upper thermal tolerance in anadromous salmonids. To assess thermal performance in fishes, it has become commonplace to measure the response of maximum heart rate to warming using electrocardiograms. However, electrocardiograms do not provide insight into the hemodynamic characteristics of heart function that can impact whole-animal performance. Doppler echocardiography is a popular tool used to examine live animal processes, including real-time cardiac function. This method allows for nonsurgical measurements of blood flow velocity through the heart and has been used to detect abnormalities in cardiovascular function, particularly in mammals. Here, we show how a mouse Doppler echocardiograph system can be adapted for use in a juvenile salmonid over a range of temperatures and timeframes. Using this compact, noninvasive system, we measured maximum heart rate, atrioventricular (AV) blood flow velocity, the early flow-atrial flow ratio and stroke distance in juvenile Atlantic salmon (Salmo salar) during acute warming. Using histologically determined measures of AV valve area, we show how stroke distance measurements obtained with this system can be used to calculate ventricular inflow volume and approximate cardiac output. Further, we show how this Doppler system can be used to determine cardiorespiratory thresholds for thermal performance, which are increasingly being used to predict the consequences that warming water temperatures will have on migratory fishes

Temperature-Dependent Developmental Plasticity in the Cardiorespiratory System of Atlantic Salmon

Anthropogenic climate change is expected to have pervasive impacts on the performance and viability of fishes, as increasing temperatures create aerobically constrained environments for many species. Given the rapid rates of projected temperature increases, it is critical to evaluate the capacity for fish to respond to a changing thermal environment through phenotypic plasticity. In this thesis, I examined the capacity for developmental plasticity in the thermal performance of juvenile Atlantic salmon (Salmo salar) reared under two thermal regimes from fertilization, and investigated potential mechanistic underpinnings within the cardiorespiratory system. Cardiac performance was examined using a noninvasive Doppler echocardiograph system originally designed for use in mice. This application represents a novel adaptation of this system and a significant contribution to the fish physiology toolbox. I found that a 4°C increase in developmental temperature significantly altered thermal performance at the level of the heart and enabled fish to maintain cardiac function to higher temperatures during acute warming. Developmental temperature did not mediate maximum cardiovascular capacity nor oxygen-carrying capacity of the blood. However, fish reared in elevated temperatures throughout development expressed morphological traits associated with cardiorespiratory robustness, including an increased proportion of vascularized compact myocardium and an increased respiratory surface area at the gills. Finally, I compared the ventricular proteomes of juvenile salmon reared in the two thermal regimes and found that rearing temperature altered the abundance of proteins associated with angiogenesis, oxidative metabolism, and protein homeostasis. Taken together, these patterns suggest an improved oxygen delivery system and enhanced oxidative capacity within the myocardium of fish exposed to warmer temperatures in early life. In all, I show that developmental temperature mediates acute thermal tolerance through plastic adjustments that preserve aerobic performance under high temperature conditions. This work enhances our understanding of the environmental contribution to thermal tolerance in fish and identifies cardiorespiratory strategies that may improve thermal resilience in juvenile salmonids. These findings have important implications for the conservation and management of this ecologically, economically, and culturally important species

Modulation of RECK levels in Xenopus A6 cells: effects on MT1-MMP, MMP-2 and pERK levels

Background: MT1-MMP is a cell-surface enzyme whose regulation of pro-MMP-2 and ERK activation position it as a key facilitator of ECM remodelling and cell migration. These processes are modulated by endogenous MMP inhibitors, such as RECK, a GPI-anchored protein which has been shown to inhibit both MT1-MMP and MMP-2 activity. Our previous studies have revealed a link between MT1-MMP levels, and pro-MMP-2 and ERK activation in mammalian cells, as well as MT1-MMP and RECK co-localization in Xenopus embryos. We here investigated how modulation of RECK would impact MT1-MMP and MMP-2 levels, as well as ERK signalling in Xenopus A6 cells. Results: We used a Morpholino approach to knockdown RECK, plasmid transfection to overexpress RECK, and PI-PLC treatment to shed RECK from the cell surface of Xenopus A6 cells. RECK reduction did not alter pERK or MT1-MMP levels, nor MMP-2 activity as measured by zymography; thus RECK-knockdown cells maintained the ability to remodel the ECM. RECK overexpression and PI-PLC treatment both increased ECM remodelling potential through increased MT1-MMP protein and relative MMP-2 activation levels. Conclusions: RECK changes that reduce the ability of the cell to remodel the ECM (overexpression and cell surface shedding) are compensated for by increases in MT1-MMP, and MMP-2 levels as seen by zymography

Th-17 cell activation in response to high salt following acute kidney injury is associated with progressive fibrosis and attenuated by AT-1R antagonism

Exposure of rats to elevated dietary salt following recovery from acute kidney injury (AKI) accelerates the transition to chronic kidney disease (CKD), and is dependent on lymphocyte activity. Here we tested whether high salt diet triggers lymphocyte activation in postischemic kidneys to worsen renal inflammation and fibrosis. Male Sprague-Dawley rats on a 0.4% salt diet were subjected to left unilateral ischemia-reperfusion and allowed to recover for 5 weeks. This resulted in a mild elevation of CD4(+) T cells relative to sham animals. Contralateral unilateral nephrectomy and elevated dietary salt (4%) for 4 extra weeks hastened CKD and interstitial fibrosis. Activated T cells were increased in the kidney threefold after 4 weeks of elevated dietary salt exposure relative to post-AKI rats before salt feeding. The T cell subset was largely positive for IL-17, indicative of Th-17 cells. Because angiotensin II activity may influence lymphocyte activation, injured rats were given the AT1R antagonist, losartan, along with high salt diet. This significantly reduced the number of renal Th-17 cells to levels of sham rats, and significantly reduced the salt-induced increase in fibrosis to about half. In vitro studies in AKI-primed CD4(+) T cells indicated that angiotensin II and extracellular sodium enhanced, and losartan inhibited, IL-17 expression. Thus, dietary salt modulates immune cell activity in postischemic recovering kidneys because of the activity of local RAS, suggesting the participation of these cells in CKD progression post-AKI

Demographic Predictors of Adult Behaviors in the Pediatric Postoperative Environment

Over 85% of children experience postoperative pain. If poorly treated, pediatric postoperative pain may lead to various negative health outcomes. Adult behaviors may be associated with child experiences in the postoperative environment. For example, adult behaviors such as distraction, humor, and coping advice divert a child’s attention away from their pain and thus, may significantly reduce child postoperative distress. In contrast, adult behaviors such as empathy, reassurance, and apology direct a child’s attention towards their pain which may increase a child’s overall postoperative distress. Moreover, patient demographic factors, like child ethnicity, may significantly alter the frequency of use of these adult behaviors. Therefore, this study aimed to determine which participant demographic factors are associated with the use of certain adult behaviors in response to child postoperative distress. This study included children ages 2 to 10 years old (N=112) undergoing elective surgery at the Children’s Hospital of Orange County. Participant demographics including ethnicity and race were collected prior to surgery. Nurse, parent, and child postoperative behavioral interactions were video recorded in the Post Anesthesia Care Unit (PACU). From these video recordings, adult behaviors were coded for their frequency of use. Multiple regressions analyses showed that adults were more likely to use humor with Non-Hispanic White children compared to Hispanic children (b = 0.393, p = 0.049). Moreover, fathers were marginally more likely to use empathy, reassurance, and apology with Hispanic children compared to Non-Hispanic White children (b = 0.249, p = 0.05). These results suggest that Hispanic and Non-Hispanic White children may receive different behavioral treatment in response to their postoperative distress. Implications for these findings suggest that child ethnicity may be predictive of different adult PACU behaviors which may illustrate how cultural differences can influence the child postoperative experience

Pharmacy students’ perceptions and attitudes towards experiential training in Jordan and United Kingdom

Purpose: To examine the quality of pharmaceutical experiential training by developing an experiential training survey. Methods: An online survey was placed on E-learning platforms in Jordan and UK to develop a validated instrument that can assess pharmacy students' perceptions of the experiential program implemented in their curricula. Results: A total of 377 students from Jordan (250 students) and the UK (127 students) completed the survey. Principal component analysis was used to conduct exploratory factor analysis and to assess the factor structure for the data. A two-factor model was applied to the data obtained from the students. These factors included students’ feelings toward experiential training (Perceiver Feelings; PF) and their ability to conduct a full Pharmaceutical Care Plan (PCP). Students from both Jordan and the UK showed a higher satisfaction PF score toward the experiential training program compared to PCP. Being female and not having prior practice experience led to significantly lower PCP scores compared to males and having a prior practice experience, respectively. Conclusion: The availability of a validated questionnaire will help in investigating the effectiveness of experiential training courses. Keywords: Experiential training; Factor Analysis; Survey development; Pharmac

High Altitude Venus Operations Concept Trajectory Design, Modeling and Simulation

A trajectory design and analysis that describes aerocapture, entry, descent, and inflation of manned and unmanned High Altitude Venus Operation Concept (HAVOC) lighter-than-air missions is presented. Mission motivation, concept of operations, and notional entry vehicle designs are presented. The initial trajectory design space is analyzed and discussed before investigating specific trajectories that are deemed representative of a feasible Venus mission. Under the project assumptions, while the high-mass crewed mission will require further research into aerodynamic decelerator technology, it was determined that the unmanned robotic mission is feasible using current technology

Scapular Performance in Women with Breast Cancer Compared to Healthy Controls

The Scapular Flip Test is designed to recognize abnormal scapular position defined by winging/tipping of the scapula on resisted external rotation. Originally created to detect scapular dysfunction with spinal accessory nerve damage, the Scapular Flip Test may be a simple screening tool for any scapular dysfunction that results from breast cancer surgery and treatment to the shoulder and axillary region.https://ecommons.udayton.edu/dpt_symposium/1020/thumbnail.jp