Gastrointestinal Cell Injury and Percieved Symptoms after Running the Boston Marathon

Gastrointestinal (GI) disturbances are a prevalent cause of marathon related complaints, and in extreme cases can promote life-threatening conditions such as exertional heat stroke. PURPOSE: Our aim was to study intestinal cell injury (via intestinal fatty acid binding protein [I-FABP]) and perceived GI distress symptoms among marathon runners. Potential risk factors (e.g., inadequate sleep) that could exacerbate GI disturbances in healthy, trained endurance runners were also examined. METHODS: A parallel mixed-methods study design was utilized. 2019 Boston Marathon participants were recruited via email. Before the race subjects completed surveys describing demographics and training history. Immediately pre-race, post-race, and 24-hours post-race participants completed a GI questionnaire to assess presence and severity of symptoms, a survey regarding risk factors (e.g., recent illness, medications) that could promote GI disturbances, and provided a urine sample. Due to weather, blood samples were only collected immediately and 24-hours post-race. RESULTS: A total of 40 runners (males: n = 19, age = 44.9 ± 10.8 years; females: n = 21, age = 44.8 ± 10.6 years) completed this study. I-FABP significantly decreased from post-race (3367.5 ± 2633.5 pg/ml) to 24-hours post-race (1657.3 ± 950.7 pg/ml, t(39) = -4.228, p \u3c .001, d = -.669). A significant difference in overall GI symptom scores across the three time points occurred (F(2, 39) = 41.37, p \u3c .001). Compared to pre-race (.09 ± .12) and 24-hour post-race (.44 ± .28), the highest average score occurred post-race (.84 ± .68). Post-race I-FABP (r = .31, p = .048) and post-race urine specific gravity (r = .33, p = .041) were significantly correlated with post-race GI symptom scores. CONCLUSION: Our study further supports the individualized presentation of GI disturbances, with participants experiencing a wide range of risk factors that can influence the extent of GI damage and perceived symptoms during and after exercise

Cryptococcus: from environmental saprophyte to global pathogen.

Cryptococcosis is a globally distributed invasive fungal infection that is caused by species within the genus Cryptococcus which presents substantial therapeutic challenges. Although natural human-to-human transmission has never been observed, recent work has identified multiple virulence mechanisms that enable cryptococci to infect, disseminate within and ultimately kill their human host. In this Review, we describe these recent discoveries that illustrate the intricacy of host-pathogen interactions and reveal new details about the host immune responses that either help to protect against disease or increase host susceptibility. In addition, we discuss how this improved understanding of both the host and the pathogen informs potential new avenues for therapeutic development

Glucocorticoid receptors in the prefrontal cortex regulate stress-evoked dopamine efflux and aspects of executive function

Enhanced dopamine efflux in the prefrontal cortex is a well-documented response to acute stress. However, the underlying mechanism(s) for this response is unknown. Using in vivo microdialysis, we demonstrate that blocking glucocorticoid receptors locally within the rat prefrontal cortex results in a reduction in stress-evoked dopamine efflux. In contrast, blocking glucocorticoid receptors in the ventral tegmental area did not affect stress-evoked dopamine efflux in the prefrontal cortex. Additionally, local administration of corticosterone into the prefrontal cortex increased prefrontal dopamine efflux. The functional impact of enhanced dopamine efflux evoked by acute stress was demonstrated using a cognitive task dependent on the prefrontal cortex and sensitive to impairment in working memory. Notably, stress-induced impairments in cognition were attenuated by blockade of glucocorticoid receptors in the prefrontal cortex. Taken together, these data demonstrate that glucocorticoids act locally within the prefrontal cortex to modulate mesocortical dopamine efflux leading to the cognitive impairments observed during acute stress

SEX DIFFERENCES IN HYDRATION AND ACUTE KIDNEY INJURY BIOMARKERS AT THE 2019 B.A.A. BOSTON MARATHON

Whitley C. Atkins1, Cory L. Butts2, Melani R. Kelly3, Chris Troyanos4, R. Mark Laursen5, Andrew Duckett5, Dawn M. Emerson3, Brendon P. McDermott1, FACSM 1University of Arkansas, Fayetteville, Arkansas; 2Weber State University, Ogden, Utah; 3University of Kansas, Lawrence, Kansas; 4Boston Athletic Association, Boston, Massachusetts; 5Boston University, Boston, Massachusetts There are several studies demonstrating that acute kidney injury (AKI) is common immediately following marathon running. Many studies further suggest complete biomarker recovery within 24-hr. To date, however, sex differences in distance runners have received little investigation. Purpose: To evaluate sex differences on hydration and AKI biomarker changes surrounding running a marathon. Methods: Sixty-three participants (32 males and 31 females) in the Boston Athletic Association’s Boston Marathon (45.9 ± 9 y, 65.4 ± 10.8 kg, finishing time 3.78 ± 0.55 h) provided urine samples at three time points (pre-marathon, post-marathon and 24-hr postmarathon) for this study. Urine specific gravity (USG) was analyzed via refractometry and AKI biomarkers were evaluated using commercially available enzyme-linked immunosorbent assays. A 2 x 3 (sex x time) RM-ANOVA was used for statistical analysis post-hoc comparisons were completed with Bonferroni adjustments due to multiple time point comparisons. Results: Female USG (1.020 ± .001) was significantly greater post-marathon than male USG (1.016 ± .001; p = .028), yet male USG (1.024 ± .002) was significantly elevated 24-hr post-marathon compared to females (1.017 ± .002; p=.008). Female uCr values (186.91 ± 32.08 mg/dL) were significantly greater 24-hr post-marathon than males (59.24 ± 34.76 mg/dL, p ). Urinary neutrophil gelatinase-associated lipocalin (uNGAL) post-marathon was greater for both males (33.94 ± 10.84 ng/mL) and females (48.02 ± 10.00 ng/mL, p≤.001) compared to baseline (males: 4.27 ± 5.75 ng/mL, females: 22.68 ± 5.19 ng/mL). Twenty-four-hr post-marathon uNGAL was greater for both sexes (males: 65.76 ± 5.61 ng/mL, females: 60.16 ± 5.16 ng/mL, p=.004) compared to pre-marathon and post-marathon values but the effect of sex on uNGAL was not significant (p=.300). Conclusions: We identified persistent elevations in AKI biomarkers beyond 24-hr, regardless of sex. Further, this study highlights apparent sex differences in hydration and AKI outcomes of runners completing marathons. The need to further investigate sex differences and potential interactions between marathon running, hydration outcomes, hormone levels and AKI is warranted

Supplementary methods, figures, and tables from Evolutionary and structural analyses uncover a role for solvent interactions in the diversification of cocoonases in butterflies

This single PDF contains methods, figures, and table

Effects of temperature and subspecies during critical early life history stages of largemouth bass (<i>Micropterus salmoides</i>)

Largemouth bass (LMB), Micropterus salmoides, is the most popular sportfish in the United States, with an expanding global food market. Farmers traditionally raise LMB in earthen ponds that are often plagued with high mortality during the early life history stages. Replacing initial pond stages with intensive indoor culture would streamline production and minimize losses. Our objectives were to (i) identify an optimal thermal regimen for rearing LMB in an indoor recirculation aquaculture system (RAS), (ii) assess the performance of Florida vs. Northern LMB for RAS culture, and (iii) elucidate thermally induced phenotypic changes and inter-linked expression of targeted genes involved in early development. Using RAS, Florida and Northern LMB were raised at 21 °C, 24 °C, and 27 °C. Fish were randomly sampled at 2 to 28 days post-hatch (dph) for total length (TL), body area (BA), myotome height (MH), jaw length (JL), eye diameter (ED), oil droplet area (ODA), and yolk area (YA). Condition index, yolk utilization efficiency (YUE), and yolk utilization rate (YUR) were calculated. Wet weight and survival were taken at 29 dph with expression of targeted genes [growth hormone (gh), insulin-like growth factor 1 (igf1), heat shock protein 70 (hsp70)] determined at 8 and 28 dph. There was a temperature effect on all morphometric traits, where both subspecies increased in size over the temperature gradient, with the largest morphometric traits (TL, BA, MH, JL, ED) detected at 27 °C. Larvae had smaller remaining ODA and YA reserves as temperatures increased. Larvae reared at 27 °C utilized their yolk at faster rates and were most efficient at converting yolk reserves to body size. Northern LMB had higher YUE than Florida LMB and were typically larger and heavier at 29 dph. LMB reared at 21 °C had higher survival than those at 24 or 27 °C, while Northern LMB had higher survival than Florida LMB. For Florida LMB, no differences in gh and igf1 were detected across temperatures at 8 dph. However, at 28 dph, these genes were upregulated at 27 °C, while expression of hsp70 was downregulated at 24 and 27 °C. Northern LMB showed similar expression patterns, with no significant differences detected. In conclusion, the present study results suggest that 1) rearing LMB at 27 °C may improve growth performance during early ontogeny, and 2) Northern LMB may be selected for faster growth when reared in an indoor RAS