bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Intensity Intervals Expand Plasma and Improves Exercise Performance in Acute Hypoxia
Authors: Gillum Trevor , Gorini Felipe 
Published: April 2020

IntroductionHypoxia causes decrements in submaximal and maximal exercise performance. Hypervolemia may improve O2 delivery to the metabolically active tissue, thus lowering physiological and cardiovascular strain during moderate exercise at altitude. Since significant time is needed to acclimate to exercise in hypoxia, we sought to expand plasma volume (PVE) through a single bout of high intensity intervals (HII) in an attempt to expedite improvements in aerobic performance.PurposeTo determine if the hypervolemic response to a single bout of HII was sufficient to mitigate the hypoxia associated declines in exercise capacity.MethodsIn our randomized counterbalanced study, 7 males (24.4 ± 5.8 years, VO2max 46.9 ± 5.8 ml kg−1 min−1, 12.8 ± 4.4% body fat) performed two 15km cycling time‐trials (TTs) in normobaric hypoxia (FiO2 = 15%) before and 48 hours following HII (8x4 minutes at 85% VO2max with 4 minutes rest between rounds) or a control bout (CON) performed at 50% VO2max, in which duration was extended to assure identical kilojoules completed between conditions. Pre‐exercise blood samples were collected to quantify changes in plasma volume, while hemodynamic data were collected utilizing PhysioFlow.ResultsIncreased PVE was observed 24 hours (6.96% ± 4.84%) and 48 hours (9.77% ± 4.26%) (p<0.05) following HII while the CON condition decreased plasma volume 48 hours post (−3.75% ± 2.62%) (p<0.05). Under the HII condition, participants showed an improvement in TT performance (Time: 1880 ± 215s to 1840 ± 203s, Power: 164.8 ± 41.2W to 171 ± 39.5W) (p < 0.05) and lowered HR (164.5 ± 9.5 bpm to 161.9 ± 8.8 bpms) (p < 0.05). Stroke volume (SV) and cardiac output (Q) manifested an upwards trend during TT performance within the HI condition (p = 0.09 and p = 0.08, respectively). There was no difference in performance, Q, or SV in the CON condition. Hydration, RPE, SaO2, and blood lactate were similar in both TTs in hypoxia.ConclusionA single bout of HII resulted in increased cycling performance in acute hypoxia, accompanied by an enhanced PVE both 24 and 48 hours following exercise. This observed enhancement in cardiac efficiency following intense exercise may be desirable in military populations or individual needing to complete physical tasks at moderate altitude without the means or time to fully acclimatize.
Disruption of estrogen regulation of orexin neurons: a novel mechanism in the pathophysiology of respiratory manifestations of panic disorder in females
Authors: Tenorio-Lopes Luana , Fournier Stéphanie , Bretzner Frédéric , Kinkead Richard 
Published: April 2020

Panic disorder (PD) is an anxiety disorder that affects ~5% of the population. A significant group of PD patients are characterised by excessive behavioral and physiological responses to CO2 inhalation. The prevalence of PD is 2 to 3 times more frequent in women yet, the origins of this sexual dimorphism are unknown; the fact that excessive responsiveness to CO2 inhalation peaks during the pre‐menstrual phase suggest a role of ovarian hormones. Early life stress is a significant risk factor for PD and there is growing evidence indicating that stress‐related increase in the function of orexin‐producing neurons (ORX) is key to PD. Based on data suggesting that 17b‐estradiol (E2) inhibits ORX, we tested the hypothesis that insufficient E2‐regulation of ORX neurons contributes to stress‐related respiratory manifestations of PD in females. Experiments were performed on adult female rats previously subjected to neonatal maternal separation (NMS; 3h/day postnatal days 3 to 12) or raised under standard conditions. In this model, NMS females show an excessive hyperventilatory response to CO2 by comparison with controls; this effect is greatest during the proestrus phase. Inactivation of ORX1 receptors by SB 33486 (15 mg/kg; ip) prevents this effect. Whole cell recordings (voltage clamp) were performed on GFP‐labeled ORX neurons by AAV microinjection. Excitatory post‐synaptic currents (EPSCs) converging onto ORX neurons were recorded under basal conditions and following E2 bath application (100nM; 10 min). Monitoring of the estrus cycle showed that in control females, EPSC frequency was inversely proportional to circulating E2 levels associated with each phase. This relationship was not observed in NMS females; EPSC frequency of NMS females was greater than controls during the proestrus phase. E2 application reduced EPSC frequency (but not amplitude); however, this effect was not affected by stress or the estrus cycle phase. We conclude that NMS disrupts E2‐mediated inhibition of ORX neurons. This is a novel mechanism in the pathophysiology of PD.Support or Funding InformationSupported by an operating grant from the Canadian Institutes of Health Research
Physiological Adaptations During the Acclimatization To‐ and Deacclimatization From‐Chronic Hypercapnia
Authors: Buchholz Kirstyn , Burgraff Nicholas , Neumueller Suzanne , Pan Lawrence , Hodges Matthew , Forster Hubert 
Published: April 2020

Respiratory disturbances, such as chronic obstructive pulmonary disease (COPD), are often associated with chronically elevated arterial CO2 (PaCO2 >45mmHg), which has been linked to an increase risk of all‐cause mortality. Additionally, acute exacerbations of respiratory symptoms may lead to greater levels of PaCO2 that require mechanical intervention to restore PaCO2 to control levels.Many physiological effects of chronic hypercapnia have been previously reported, and include robust adaptations in acid/base, and respiratory control mechanisms. However, the effects of restoring PaCO2 to control levels following chronically elevated PaCO2 are largely unknown. Thus, the goal of my project is to gain insight into the physiological and ventilatory control adaptations during the acclimatization to‐ and deacclimatization from‐chronic hypercapnia. Based on studies focusing on the deacclimatization from chronic hypoxia, I hypothesize that deacclimatization from chronic hypercapnia would not be completed within 24 hours of return to normoxia.To assess the effects of deacclimatization from chronic hypercapnia, I measured the temporal pattern of ventilation, ventilatory CO2/[H+] chemoreflex, and acid‐base status during acclimatization to‐ and deacclimatization from‐chronic exposure to elevated inspired CO2 (InCO2) in goats. Goats were chronically housed in environmental chambers that allowed for modification of ambient CO2 levels. Following a room air control period, goats were exposed to an InCO2 of 6% for 30 days, followed by returned to room air for 24 hours (hrs). Within 1 hour of 6% InCO2, VI increased to 322% above control, but decreased slightly to 293% above control after 24 hours. By Day 2 of exposure, PaCO2 increased 15 Torr and changed minimally thereafter. pH decreased by 0.06 units upon initial exposure but was partially compensated by Day 5 due to an 8mEq/L increase in arterial [HCO3−]. Within 4hrs of deacclimatization, VI decreased to 123% above control, and continued to decrease to near control levels by 24hrs. PaCO2 decreased 13mmHg by 24hrs, while pH increased 0.04 units. The CO2/[H+] chemoreflex was assessed by increasing InCO2 to 3, 5, and 7% at 4 and 24 hours of deacclimatization. The chemoreflex was above control at 4 and 24 hours of deacclimatization. The steady‐state ventilation/[H+] relationship was also slightly elevated at 4 and 24hrs.Taken together, these data suggest that deacclimatization from chronic hypercapnia is nearly complete by 24 hours. Further studies will extend the recovery time to 5 days to see if the deacclimatization is complete. Additional studies will aim to use western blotting to investigate neurological adaptations underlying the deacclimatization processSupport or Funding InformationDepartment of Veteran Affairs
Sex Specific Changes in SOD1 Proteomics in Acute Ischemic Stroke
Authors: Frank Jacqueline , Maglinger Benton , Roberts Jill , Trout Amanda , Stowe Ann , Grupke Stephen , Pennypacker Keith , Fraser Justin 
Published: April 2020

IntroductionSuperoxide Dismutase 1 (SOD1) plays an important anti‐oxidant role by destroying free superoxide radicals, and serum levels increase in response to smoking, which is a known risk factor for stroke. The pathology of ischemic stroke includes activation of free radical pathways within the ischemic tissue. Through our previously published Blood and Clot Thrombectomy Registry and Collaboration (BACTRAC) stroke tissue bank (clinicaltrials.gov NCT03153683), we aimed to determine any relationship between intracranial peri‐infarct intraluminal SOD1 proteomics and sex, smoking status, and immediate outcome in stroke patients.MethodsPlasma samples were processed in accordance with the BACTRAC protocol, and underwent Proximity Extension Assay (PEA) via Olink. For each protein, intracranial expression distal to the stroke thrombus was compared to the same subject’s systemic arterial blood as an internal control. Smoking status, and sex difference were analyzed using appropriate two‐way comparisons and regression.Results22 adult subjects (>18yrs) were included in the study, of which 13 (59%) were female. Median age was 64 (24–91). 7 (32%) were active smokers and 5 (23%) had a previous stroke. Mean infarct time was 552 ± 254 minutes and mean infarct volume was 62,361 ± 87,735 mm3. The female population intracranial SOD1 expression was greater in active smokers (p=0.004). No significant change in systemic arterial plasma levels were found in either sex.
Moreover, SOD1 intracranial levels adjusted to systemic controls also heeded a sex specific increase in female smokers (p=0.05).ConclusionsSOD1 protein expression was found to be significantly increased in only the intracranial distal‐to‐thrombus blood of females based on smoking status. There were no significant findings of SOD1 expression in the male population. These data suggest that changes in SOD1 expression are acutely sensitive to smoking status, but that such changes are particular to women, emphasizing a major difference in how men and women process stroke pathophysiology.Support or Funding InformationUniversity of Kentucky Center of Clinical and Translational Science
Changes in Morphology of Primary Muscle Cells Exposed to Di‐(2‐ethylhexyl) Phthalate
Authors: Zenteno-Savín Tania , Hernández-Almaraz Pablo , Lugo-Lugo Orlando , Gaxiola-Robles Ramón , Vázquez-Medina José Pablo , Ramírez-Jirano Luis Javier 
Published: April 2020

Di‐(2‐ethylhexyl) phthalate (DEHP) is used in plastic manufacture mainly to provide flexibility. Asthma, infertility, endocrine disruption and some types of cancer have been associated with environmental DEHP exposure in humans; however, the morphological, biochemical and physiological changes that lead to these pathologies have not been reported. The objective of this study was to analyze morphological changes in muscle cells exposed to DEHP. Abdominal muscle samples were collected from healthy women subjected to programmed cesarean section at Hospital de Especialidades Médicas de La Paz, in La Paz, Baja California Sur, México, and were subjected to cell culture at 35°C with 5% CO2 and constant humidity. Primary smooth muscle cells (4.0 x 105 cells mL−1) from both species were exposed to 1000 μM DEHP for 13 days. Untreated controls reached 100% confluency, underwent constant mitotic divisions and had normal cell morphology throughout. In contrast, cells exposed to DEHP did not reach confluency beyond 85%, had significantly lower cell viability and total protein content at day 13 of exposure. Cells exposed to DEHP were distended and had granules in the cytoplasm, which were evident since day 2 of exposure and covered all the cytoplasm by day 13. In numerous cells, bright yellow refringent, round bodies were observed in the cytoplasm, with variable size and number among cells. These spheres were observed from day 2 of exposure and are presumed to be DEHP accumulated inside the cells. These intracellular DEHP deposits could be associated with the observed cell mortality and morphology changes and could potentially lead to the reported pathologies onset and progression. This research was conducted in accordance with institutional ethical standards and with the 1964 Declaration of Helsinki and later amendments; informed consent was obtained from all participants included in the study. The informed consent form and research protocol were approved by the Ethics Committee of Instituto Mexicano del Seguro Social.Support or Funding InformationConsejo Nacional de Ciencia y Tecnología (CONACYT‐Fronteras 2016‐01‐2305)
Characterizing the microbiota‐gut‐brain axis in a murine model of pediatric inflammatory bowel disease
Authors: Stokes Patricia , Salvo Eloisa , Knotts Trina , Rabasa Gonzalo , Sladek Jessica , Gareau Melanie G. 
Published: April 2020

BackgroundInflammatory bowel diseases (IBD) are chronic intestinal diseases affecting over 1.4 million Americans. Pediatric patients are especially vulnerable to the psychiatric effects seen in IBD as they are still undergoing brain maturation and neuroplasticity during periods of significant GI inflammation. A murine model of pediatric IBD and the mechanism(s) in which the microbiota‐gut‐brain axis is altered during this developmental time have yet to be identified.AimOur goal was to develop a pediatric model of IBD and assess the effect on the microbiota‐gut‐brain axis at adulthood.HypothesisWe hypothesized that induction of ulcerative colitis by dextran sodium sulfate (DSS) at weanling mice (P21) would lead to lasting effects on the microbiota‐gut‐brain axis into adulthood, including behavioral deficits.MethodsC57BL/6 mice (male and female) were weaned (P21) and treated with 2% DSS (or vehicle) for 5 days in the drinking water. In early adulthood (6–8 weeks of age), behavioral tests were performed (novel object recognition task [NOR], light/dark [L/D] box and open field test [OFT]) and tissue samples collected for PCR, immunofluorescence and microbiota analysis.ResultsDSS‐treated mice showed impaired object recognition and increased anxiety‐like behaviors compared to vehicle controls. Hippocampal gene expression showed increased expression of the pattern recognition receptors (Nod1 and Nod2), inflammatory cytokines (IL17ar, IL23 and IL22) along with a decreased expression of the neuronal activation markers (cFOS). Cell proliferation in the hippocampal dentate gyrus as quantified by doublecortin (DCX) staining showed significantly less DCX than vehicle controls. Finally, microbiota assessment identified persistent dysbiosis in DSS‐treated mice on alpha diversity, taxa abundance and phylum abundance compared to vehicle controls.ConclusionsTaken together, these results indicate that acute DSS‐induced colitis in early adolescence can have long‐lasting effects on the microbiota‐gut‐brain axis in adulthood. Future studies will assess whether administration of probiotics can ameliorate these colitis‐induced microbiota‐gut‐brain axis deficits.Support or Funding InformationFunding provided by Crohn’s & Colitis Foundation (CCFA)
The CB1 cannabinoid receptor‐mediated inhibition of cAMP accumulation in neuroblastoma cells: role of different Gi/o protein subtypes
Authors: Eldeeb Khalil , Wittmann Thomas G. , Leone-Kabler Sandra , Howlett Allyn C. 
Published: April 2020

The CB1 cannabinoid receptor (CB1R) is a G protein coupled receptor with robust expression in the nervous system. CB1R signaling is mediated by pertussis toxin (PTX)‐sensitive Gi /o proteins, and leads to inhibition of adenylyl cyclase. Because of the importance of the cyclic AMP pathway in differentiated neuronal functions, the investigation of G protein subtypes involved in the inhibition of adenylyl cyclase activity is of particular interest. The aim of the present study is to investigate the effect of individual Gi/o proteins on CB1R‐promoted inhibition of forskolin‐ stimulated cAMP accumulation in N18TG2 neuroblastoma cells. We utilized [3H]cAMP binding competition assay and cell membranes in ligand‐modulated [35S]GTPγS binding and scintillation proximity assay (SPA) as previously described (
Blume et al 2015 and
Eldeeb et al 2017).The CB1R agonist, CP55940 (100 nM) inhibited forskolin‐stimulated cAMP accumulation to 34±8% of forskolin alone. Pretreatment with 100 ng/ml of PTX for 20 hrs attenuated CP55940 induced inhibition to 85±24% of forskolin control. In N18TG2 cells that were stably expressing either PTX‐resistant Gαo, Gαi1, Gαi2 or Gαi3 proteins, treatment of PTX‐pretreated with CP55940 (100 nM) inhibited cAMP accumulation to 38±3% Gαo, 53±4 Gαi1, 76±24 Gαi2 and 28±15% Gαi3 of forsklin alone. Using SPA, CP55940 (100 nM) stimulated [35S]GTPγS binding mediated by Gi/o protein subtypes, Gαo, Gαi1, Gαi2 and Gαi3 in N18TG2 Gαi3 PTX‐resistant cell membranes. In contrast, in PTX‐pretreated membranes CP55940 was able to stimulate [35S] GTPγS binding mediated by Gαi3 only. In conclusion, these data show that Gi/o proteins contribute differently to CB1R‐promoted inhibition of cAMP in N18TG2 cells, with greater contribution by Gαi3. This is consistent with our earlier findings of the high level of Gαi3 expression and its contribution toward total G protein activation in N18TG2 membranes (
Eldeeb et al 2017). The contribution of different G protein subtypes to CB1R signaling is necessary to consider as we evaluate CB1R functions in the nervous system.Support or Funding InformationNIH grants R01‐DA042157, P50‐DA006634
Electrospun Antimicrobial, Anti‐Inflammatory and Analgesic Bandages for Comprehensive Wound Treatment
Authors: Chirra Bhagath , Shah Kush N. , Chapman Morgan J. , Raina Rohit , Southerland Marie R. , Cannon Carolyn L. 
Published: April 2020

Chronic wounds affect more than 5 million Americans annually with an associated cost of $10 – 20 billion. These wounds provide perfect environments for bacterial growth, and are prone to infections, especially from multi‐drug resistant (MDR) pathogens. The current silver‐based bandages used to treat wounds exhibit a high toxicity toward fibroblasts, and lack anti‐inflammatory and analgesic activity. Our work focuses on the development of bandages to address these unmet clinical needs. We have fabricated electrospun polycaprolactone (PCL) scaffolds, capable of aiding in the wound healing process, and with incorporation of Ag+IBU, a novel therapeutic. These scaffolds deliver the drug locally at a controlled rate to impede bacterial infections. We have further functionalized PCL scaffolds with addition of polyethylene glycol (PEG) to accelerate drug release. Scanning electron microscopy images have revealed that our drug loaded scaffolds have a smooth fiber morphology and fiber diameter that is ~1 μm. Scaffolds loaded with either 5% or 10% Ag+IBU (w/w) release 40% of the drug within the first 24 hours. Microbiological assays have revealed that Ag+IBU‐loaded scaffolds are bactericidal against bacteria in both planktonic and biofilm growth mode. Cytotoxicity assays have revealed that Ag+IBU‐loaded scaffolds exhibit toxicity toward human dermal fibroblasts at high concentrations. However, pre‐incubation with N‐acetyl cysteine (NAC), an antioxidant metabolite, abrogates this toxicity and significantly increases cell viability. We have fabricated two‐layer scaffolds with one layer rapidly delivering NAC and the second layer slowly releasing Ag+IBU. Compared with the commercially available bandages with antimicrobial properties currently used for wounds, our non‐toxic, antimicrobial, anti‐inflammatory, and analgesic scaffolds offer a more comprehensive treatment option.Support or Funding InformationThis research is supported by NIH grant 5R21AI142327‐02
Photoaffinity Approach Reveals Antibiotic Adjuvant Activity toward Pseudomonas aeruginosa
Authors: Miller Conrad Laura C. 
Published: April 2020

Pseudomonas aeruginosa is an emerging public health threat. A common Gram‐negative source of secondary infections, it has few effective treatment options, which are currently being undermined by the rise of resistance. New therapies are urgently needed. We had previously pursued an antivirulence strategy to block the production of pyocyanin, a redox‐active virulence factor. A photoaffinity analog of an antipyocyanin compound was developed to interrogate the inhibitor’s molecular mechanism of action. In the process, antibiotic adjuvant activity was suggested by the proteomics results. Using susceptibility assays, we found that these compounds amplify the bactericidal activity of colistin, a well‐characterized antibiotic, suggesting they may represent a first‐in‐class antibiotic adjuvant therapy. Analogs have the potential to not only widen the therapeutic index of cationic antibiotic peptides like colistin, but to be effective against colistin‐resistant strains. Multidrug‐resistant infections with P. aeruginosa are currently treated with colistin and the related polymyxin b, however, resistance to these drugs is also increasingly encountered. The adjuvants have the potential to preserve the life‐saving therapy of colistin when used in a combination therapy.Support or Funding InformationNational Institutes of Health 5SC3GM118199California State University Program for Education & Research in Biotechnology New Investigator Grant
Using S. cerevisiae to screen cancer mutations in the DNA damage response pathway
Authors: Shanle Erin K. , Harris Caitlin , Savas Jessica , Coddington Ashley , Ray Sreerupa 
Published: April 2020

When DNA is damaged, a DNA damage response (DDR) pathway is initiated to prevent mutations from being passed on to daughter cells. The MRN complex in humans (MRX in yeast) functions to start the DDR pathway by detecting DNA damage and is comprised of Mre11, Rad50, and Nbs1 in humans. Although mutations in members of the MRN complex pre‐dispose individuals to cancer, the functional effects of Mre11 cancer mutations have not been well characterized. The goal of this project was to investigate the effects of Mre11 cancer mutations on the DDR pathway using yeast‐based assays because the complex is highly conserved in eukaryotes. Using a database of human tumor mutations, we identified 233 cancer mutations in human Mre11, 83 of which occurred at residues that are conserved between yeast and human. A subset of these mutations were screened for functional effects in yeast by creating the cancer mutations at the conserved residues in yeast Mre11. Yeast expressing wild‐type or mutant Mre11 were then assessed for DNA damage sensitivity using hydroxyurea (HU) and methyl methanesulfonate (MMS). Results indicate that N‐terminal point mutations in yeast Mre11 do not confer sensitivity to DNA damage in yeast cells suggesting that these regions may have conserved sequence without conserved function. However, one mutation near the capping domain of Mre11 does show the disfunction of the yeast Mre11 protein similar to the deletion strain. Using yeast‐based assays, cancer mutations can rapidly be screened for functional effects on DDR pathways.Support or Funding InformationLongwood University Faculty Research and Development Grant