bluuebunny/crossref_metadata_2025_split huggingface dataset:
Racial Differences in Blood Pressure Variability, Baroreflex Sensitivity and Heart Rate Variability Following Maximal Exercise
Authors: Kappus Rebecca M , Ranadive Sushant M , Yan Huimin , Lane Abbi D , Cook Marc D , Wilund Kenneth R , Woods Jeffrey A , Fernhall Bo 
Published: June 2021

IntroductionHeart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS), measures of autonomic nervous system function, are associated with cardiovascular (CV) outcome. African Americans (AA) have an increased prevalence of CV disorders in comparison to Caucasians (C).PurposeTo determine race specific responses in BPV, BRS and HRV before and after maximal exercise.Methods37 AA and 37 C (24 years) underwent maximal exercise on a cycle ergometer. BPV, BRS and HRV measurements were assessed using finger plethysmography before and after exercise. Data were log transformed and pre‐and post‐max test values were compared by race.ResultsAcute exercise significantly decreased BRS, LF‐HRV and HF‐HRV and significantly increased LF/HF‐HRV in both AA and C. With exercise, C significantly decreased measures of BRS and HRV more compared to AA; BRS‐SAPRRI transfer mean (C: 2.65±.54 to 1.09±.81 versus AA: 2.70±.40 to 1.70±.92), BRS‐down down (C: 3.21±.55 to 1.74±.49 versus AA: 3.28±1.0 to 2.2±.71), HRV‐LF (C: 6.39±.86 to 3.68±1.42 versus AA: 6.37±1.24 to 5.18±2.14) and HRV‐HF (C: 7.38±1.23 to 3.53±1.73 versus AA: 7.51±1.09 to 5.38±2.16).ConclusionC exhibited increased vagal withdrawal and greater reductions in BRS compared to AA in response to acute exercise. The impact of these racial differences in autonomic control on CV risk needs further investigation.
Central sympathoinhibition by moxonidine attenuates brain oxidative stress, prevents cardiac remodeling and improves prognosis associated with reduction of sympathetic hyperactivity in rats with hypertensive heart failure
Authors: Honda Nobuhiro , Hirooka Yoshitaka , Matsukawa Ryuichi , Ito Koji , Sunagawa Kenji 
Published: June 2021

BackgroundHypertension causes hypertensive heart failure (HHF). In HHF, excessive sympathoexcitation leads to poor prognosis. However, the effect of central sympathoinhibition on survival in HHF remains unclear. Therefore, we examined whether moxonidine, a sympathoinhibitory agent acting on nischarin associated with oxidative stress, improves prognosis in a rat model of HHF and has antioxidant effects in the brain.Methods and ResultsWe fed Dahl salt‐sensitive (DS) rats with high salt diet (HS) to create a model of HHF. This model represents a compensated left ventricular (LV) hypertrophic stage, subsequently a HF stage. We used DS rats with HS as HHF and performed intracerebroventricular infusion of moxonidine or vehicle to evaluate the effect of central sympathoinhibition. In comparison with vehicle, moxonidine decreased urine norepinephrine (2.8±0.2 vs. 1.7±0.3 μg/day, p<0.01), improved survival (23 vs. 76 %, p<0.05) as well as LV function (LVDd; 6.9±0.2 vs. 6.4±0.1 mm, p<0.05, %FS; 38±1 vs. 45±1 %, p<0.01, LVEDP; 14.2±2.7 vs. 7.3±1.7 mmHg, p<0.05, LV −dP/dt; −7738±348 vs. −10394±1156 mmHg/s, p<0.05). Moreover, moxonidine decreased LV fibrosis and brain oxidative stress (Signal Decay Rate; 0.12±0.01 vs. 0.10±0.01/min, p<0.05).ConclusionMoxonidine‐induced central sympathoinhibition attenuates brain oxidative stress, prevents cardiac remodeling and improves prognosis in rats with HHF.
Psycho Social Stressors in Elderly Assessed with Heart Rate Variability
Authors: Marck Jan Willem , Kallen Victor L. , Issa Amine N. , Kasak Alex J. , Smethana Michael , Johnson Bruce D. 
Published: June 2021

BACKGROUNDPsycho‐socio stressors may over time result in dominance of the sympathetic nervous system (SNS) over the parasympathetic nervous system (PNS). Reduced PNS control over cardiovascular processes has been associated with decreased health. Heart rate variability (HRV) has been proposed as a technique to quantify SNS and PNS interactions and thus might offer a noninvasive predictive index.OBJECTIVETo investigate the impact of real‐life stressors on HRV fluctuations in independent living elders (EL).METHODSFor three months every two weeks EL (N=22; Age=75±9; M/F ratio=17/5) performed autonomic tests consisting of quiet breathing, paced breathing and hand grip. All did a questionnaire assessing depression, positive/negative live events, and isolation.RESULTSNegative events (r=0.36, p=.01) and isolation (r=0.35, p=0.02) are correlated with HR. Personal changes in HRV, SDNN (r=−0.43, p<0.005) and Poincare Width (r= −0.42, p<0.005), are correlated to negative life events.CONCULSIONNegative life events reduce HRV which suggests either SNS activation and/or PNS withdrawal.Research was made possible by Healthy for Life, TNO, and the Center for Innovation, Mayo Clinic.
Blunted cardiovagal arterial baroreflex gain to acute hypertension in young black men
Authors: Keller David M , Holwerda Seth W , Credeur Daniel P , Fadel Paul J 
Published: June 2021

Blacks are at an elevated risk for developing hypertension. Although carotid baroreflex control of heart rate in blacks has been investigated, little is known regarding integrated arterial baroreflex (ABR) control of the heart in blacks. Thus, we tested the hypothesis that cardiovagal ABR is reduced in blacks compared to whites. The slope of the relationship (i.e., gain) between changes in systolic blood pressure and r‐r interval were determined in 16 non‐hypertensive men (7 black and 9 white, age 18–27 yr) using 100μg iv bolus of sodium nitroprusside (NTP) followed 1 min later by 150μg bolus of phenylephrine (PE) during rest (3 trials). In addition to analysis of the complete mod‐Ox trials (overall ABR gain), separate linear analyses of the NTP (hypotenion) and the PE (hypertension) phases were also performed. Overall ABR gain was not different between racial groups (black: 14±4 vs white: 13±4 ms/mm Hg, p=0.64). Although the gain for the NTP phase was also not different between groups (p=0.17), the gains for the PE phase were significantly reduced in blacks (10±4) compared to whites (18±10 ms/mm Hg; p=0.04). These findings indicate that blacks have diminished ABR responses to acute hypertensive stimuli and support racial differences in cardiovagal ABR function between black and white men.Supported by NIH R15HL096103 (DMK) and RO1 HL093167 (PJF)
ACE2 inhibits Endoplasmic Reticulum stress and autophagy associated to neurogenic hypertension
Authors: Xia Huijing , Johnson Tanya , Mungrue Imran , Lazartigues Eric 
Published: June 2021

Endoplasmic reticulum (ER) stress has recently been suggested to contribute to the development of hypertension. We hypothesized that ACE2, a counter regulator of the Renin‐Angiotensin System, could oppose the Angiotensin‐II‐mediated activation of ER stress in neurons. In vitro, Neuro 2A cells treated with Ang‐II (100 nM, 24 h) show significant increases (qRT‐PCR) in ER stress and autophagy markers (fold change, P<0.05): IRE1 (2.0 ±0.3), EIF2α (2.0 ±0.1), EIF2α kinase (2.0 ±0.3) and CHOP (1.3 ±0.1). To test whether ACE2 can prevent ER stress and autophagy in neurogenic hypertension, DOCA‐salt hypertension was induced in non‐transgenic (NT, n=6) and transgenic mice overexpressing ACE2 in the brain (SA, n=6). Subfornical organ and PVN punches were collected and ER stress assessed in both NT (136 ±2 mmHg) and SA (126 ± 1 mmHg) DOCA mice. DOCA‐salt hypertension significantly increased (P<0.05 vs. no treatment) ATF4 (1.6 ±0.1; 1.3 ±0.1), spliced XBP (6.5 ±0.9; 1.6 ±0.1) and CHOP (1.5 ±0.02; 1.4 ±0.2) in NT mice SFO and PVN, respectively. However, in SA mice with blunted hypertension, ATF4 (1.2±0.1; 1.0±0.03), spliced XBP (4.5±0.1; 0.9±0.2) and CHOP (1.0±0.1; 1.2±0.1) were reduced (P<0.05 vs. NT+DOCA). Our data suggest that ER stress and autophagy are increased in DOCA‐salt hypertension, through PERK‐eIF2α‐ATF4 and IRE1‐SXBP1 pathways, and ACE2 inhibits both cascades in the brain, thus reducing neurogenic hypertension.American Heart Association (12EIA8030004); NIH/NHLBI HL093178.
Ampakines induce a persistent increase in phrenic motor output in rats with cervical spinal cord injury
Authors: Sandhu Milap Singh , Elmallah Mai K , Lane Michael A , Reier Paul J , Greer John J , Fuller David D 
Published: June 2021

Cervical spinal cord injury (SCI) typically interrupts descending synaptic inputs to phrenic motoneurons resulting in diaphragm paralysis and respiratory impairment. The primary bulbospinal excitatory inputs to phrenic motoneurons are glutamatergic with AMPA receptors playing a prominent role. Ampakines are a group of compounds that can enhance the function of AMPA receptors, and prior work demonstrates that these compounds can increase respiratory output during conditions associated with blunted respiratory drive. Accordingly, in ongoing studies we are testing the hypothesis that intravenous delivery of an ampakine, CX717, will trigger increases in inspiratory phrenic motor output in rats with chronic cervical contusive SCI. Bilateral phrenic nerve activity was recorded in rats that received cervical (C3) hemicontusion of the spinal cord 8 wks prior. A single dose of CX717 (30mg/kg) triggered a modest increase in phrenic inspiratory burst amplitude ipsilateral but not contralateral to the contusion injury. However, repeated doses (3 × 10mg/kg at 5min intervals) triggered a substantial and persistent increase (lasting at least 60mins) in the inspiratory burst amplitude recorded in both phrenic nerves. These results demonstrate ampakines can increase phrenic motor output after cervical SCI and may provide a new means of enhancing respiratory function after SCI.Support: Craig H. Neilsen Foundation #220521 (MSS), Parker B. Francis Fellowship (MKE), 1R01NS080180–01A1 (DDF), NIH1R21HL104294–01 (DDF)
Stress‐induced activation of a distinct subpopulation of GABA neurons in the basolateral amygdala of male and female rats
Authors: Bolanos Juan M , Lopez Alejandra E , Middleton Capri B , Del Cid Jiselle J , Hamdan Jameel N , Ruiz Christina C , Gosselink Kristin L 
Published: June 2021

Previous studies have shown that a repeated 6‐hr restraint stress causes hippocampal plasticity and a shift in the profile of activated neurons in the basolateral amygdala (BLA), suggesting an alteration in mechanisms that direct learning and memory in repeatedly stressed individuals. The purpose of this study was to determine whether a less severe stress exposure induces similar adaptations and whether this response is sex‐specific. Adult male and female rats were acutely or repeatedly restrained for 30 min/d; brain sections were stained immunohistochemically for Fos and calbindin (CB), a marker of GABAergic neurons, and quantified in the BLA to determine cellular activation along with phenotypic profile. Significance was determined by t‐test, with p<0.05 considered significant. We hypothesized that repeated stress would decrease the number of BLA neurons expressing both Fos and CB, compared to control or acutely stressed rats, but that these effects would not differ between sexes. In support of our hypothesis, the number of CB‐expressing neurons in the BLA did not differ according to sex or stress treatment. However, we did not find any significant differences in the number of activated (Fos‐expressing) CB neurons in either sex in response to stress. Therefore, this specific type of GABAergic influence from the BLA to the hippocampus may not be affected by this level of stress.Supported by: 8G12MD007592
Tadalafil‐sensitive impairment in muscle blood flow during exercise in Duchenne Muscular Dystrophy
Authors: Nelson Michael , Martin Elizabeth A. , Tang Xiu , Johannes Jimmy , Lewis Joshua , Gurudevan Swaminatha V. , Victor Ronald G. 
Published: June 2021

Out‐of‐frame mutations in the dystrophin gene cause Duchenne muscular dystrophy (DMD)—a devastating X‐linked muscle wasting disease for which there is no treatment other than corticosteroids. In DMD, loss of the cytoskeletal protein dystrophin impairs sarcoelmmal targeting of nNOS, which is the main source of skeletal muscle‐derived nitric oxide (NO). We previously showed that loss of nNOS impairs the normal exercise‐induced attenuation of reflex vasoconstriction in dystrophic skeletal muscle, thus implicating a putative vascular component to the pathogenesis of DMD. Here we present data on a second phenotype, that muscle blood flow (BF, measured by Doppler ultrasound of the brachial artery) fails to increase normally during mild rhythmic handgrip exercise in 6 boys with DMD (7–13 years of age) compared with 8 age‐matched male controls (Ctrls): ΔBF:+13±5% vs. +81±10%, respectively (p<.05). Moreover, we show that the phosphodiesterase 5 inhibitor Tadalafil, restores active hyperemia in boys with DMD in a dose‐dependent manner: 0.5 mg/kg, +56±13%; 1.0 mg/kg, +72+18% These data significantly advance the vascular hypothesis of DMD and implicate PDE5 inhibition as a putative therapeutic treatment option.Support: Parent Project Muscular Dystrophy, Heart and Stroke Foundation of Canada (MN)
Ursodeoxycholic acid inhibits colonic mucosal cytokine release and prevents colitis in a mouse model of disease
Authors: Ward Joseph Bernard Jude , Kelly Orlaith B , Jefferies Caroline , Murray Frank E , Fallon Padraic G , Keely Stephen J 
Published: June 2021

Toll‐like receptors (TLR) promote cytokine release from intestinal epithelia, thereby driving inflammation. Although ursodeoxycholic acid (UDCA) has anti‐inflammatory effects in the liver, its potential for treating intestinal inflammation has not been well‐studied. Here, we investigated UDCA effects on TLR‐driven colonic epithelial cytokine release and induction of inflammation in a mouse model of colitis.Resected human colonic mucosa and T84 colonic epithelial cells were treated with specific TLR agonists, in the presence or absence of UDCA. Released cytokines were measured by ELISA. Dextran sodium sulphate (DSS) colitis was induced in C57BL/6 mice along with daily intraperitoneal injections of UDCA (30 mg/kg) for 5 days. Colitis severity was recorded as disease activity index (DAI). In T84 cells, UDCA reduced TLR2 and 4‐stimulated RANTES release and TLR3‐stimulated TNFα release, compared to controls. TLR4‐driven IL‐8 release was abolished by UDCA in human colonic mucosa. Inhibitors of the transcription factors, NFκB and AP1, mimicked UDCA effects suggesting these pathways may be involved. Furthermore, UDCA treatment significantly reduced DAI in DSS‐treated mice.In conclusion, our data suggest that, by virtue of its effects in preventing TLR‐induced proinflammatory cytokine release, UDCA may be useful for treating intestinal inflammation.This work was funded by Science Foundation Ireland.
Relationship between spatial abilities and cross‐sectional drawings
Authors: Langlois Jean , Dagenais Yvan , Bellemare Christian , Lemieux Renald , Martin Marcel , Lecourtois Marc , Yetisir Elizabeth , Bergeron Germain , Hamstra Stanley , Wells George A. 
Published: June 2021

ObjectiveSpatial abilities have been related to cross‐sections of anatomical structures. The objective was to assess the relationship of spatial abilities to positioning and assessing area of structures in cross‐sectional drawings.MethodsFourth‐year medical students (n = 49) were recruited in a prospective study. Spatial abilities were measured with a redrawn Vandenberg and Kuse Mental Rotations Test in two (MRTA) and three (MRTC) dimensions and the Surface Development Test (SDT). Participants had to draw by observation the four lateral sides of objects made of several structures. After the objects were removed from view, cross‐sections of the objects were drawn. Position and area of structures within drawn objects were compared to standard. Results were expressed as means ± standard deviation and Spearman's correlation coefficient was used to assess the relationship of positional and area errors of drawn structures to MRTA, MRTC and SDT scores.ResultsPositional error (9805 ± 6699 pixels) was inversely related to MRTA (13.5 ± 5.2), MRTC (9.7 ± 4.5) and SDT (43.4 ± 10.0) scores; with a correlation of − 0.3718 (p = 0.0085), − 0.4682 (p = 0.0007) and − 0.3461 (p = 0.0149), respectively. Similarly, area error (440416 ± 131870 pixels) was not related to MRTA, MRTC and SDT scores.ConclusionSpatial abilities were related to the position, but not to the area, of structures in cross‐sectional drawings of objects.This study was supported by an internal grant from the Department of Surgery, University of Sherbrooke, Sherbrooke, QC, Canada.
Medical Student Feedback on Participating in a Combined Anatomy Curriculum, 2010–2012
Authors: Guzman Carlos , Young Stephanie , Wimmers Paul , Byus Craig , Wisco Jonathan 
Published: June 2021

First‐year medical students at the David Geffen School of Medicine at UCLA and the Thomas Haider Program in Biomedical Sciences at UCLA/UCR were asked about their experiences and their perception of the value anatomy has in the medical curriculum. Annual responses were compared to determine whether the qualitative responses changed from year to year. We conducted three annual surveys of 2nd – 4th year medical students. Students were asked how the anatomy curriculum affected their confidence in physical examination skills, preparation for USMLE board exams, and preparation for 3rd and 4th year clerkships. Most students viewed the anatomy curriculum highly in helping them prepare for USMLE board exams (89% positive response), 3rd year clerkships (95%), and developing physical exam skills (65%). When asked about how the anatomy curriculum helped prepare students for 4th year clerkships, there was a downward trend with a 92% positive response rate for 2010, 90% for 2011, and 83% for 2012. These results appear to indicate a perceived diminishing value of either anatomy pedagogy as the medical experience becomes more clinical.Grant Funding Source: AAA
Peer teaching in an online histology classroom
Authors: Barbeau Michele , Rogers Kem A 
Published: June 2021

The impact of a peer teaching exercise for an online histology course has been assessed using a mixed method approach. Students signed up for a time they would be available to meet live in the virtual classroom. Each week, students were given specific virtual slidebox assignments which they uploaded into the classroom with full annotations. At their group meeting time, members would log into the classroom and take turns presenting their slides; presentations were archived for future reference. Other students were free to ask questions and the course instructor was either present live or viewed the presentation archive at a later time to ensure accuracy or provide clarification. Laboratory grades improved significantly compared to the previous year when peer teaching was not included (+9.4% (p<0.05)). Student surveys indicated that students believed that teaching others was “very helpful” (67%) or “helpful” (33%) for enhancing their understanding of course material compared to 100% who found attending presentations “helpful” for enhancing their understanding. In summary, we have shown that peer teaching in the online environment is an effective means to enhance student learning.Grant Funding Source: Social Sciences and Humanities Reseach Council of Canada
Anatomy Academy promotes Systems‐Based Practice among medical and undergraduate students
Authors: Ojukwu Kenechukwu , Padilla Jessica , Diaz Molly , Wisco Jonathan 
Published: June 2021

Systems‐Based Practice (SBP) is difficult to define and successfully incorporate into medical education. Nonetheless, it is one of the six Accreditation Council for Graduate Medical Education (ACGME) core competencies that physicians are to attain. Competency in SBP includes understanding of the health system to allow adequate assessment and improvement of the quality of patient care and patient safety. Anatomy Academy (AA) provides a setting where UCLA medical and undergraduate students enter the community to teach fifth graders complex health concepts. Students are encouraged to compliment their pathophysiology and diagnostic training with active practice in communication, program assessment, conflict resolution, and problem solving as they teach complex medical concepts such as problematic cardiac blood flow, lung disease, and gastrointestinal function. Written reflections, program‐ and self‐evaluations suggest that AA provided opportunities to gain basic SBP skills such as improved conflict management and problem solving. Community programs such as AA can contribute to medical education curriculum by allowing early medical student exposure to SBP.Grant Funding Source: Albert Schweitzer Fellowship, UCLA Monica Salinas Fellowship
Our success in translating Anatomy Academy, an intervention program for 5th and 6th grade students, from Los Angeles, CA to Salt Lake City, UT.
Authors: Steed Kevin S , Diaz Molly , Ojukwu Kene , Padilla Jessica , Jenkins Katherine , Lassetter Jane , Wisco Jonathan J. 
Published: June 2021

Anatomy Academy (AA) is an educational intervention program to fight obesity and promote both healthy lifestyles and interest in science in children, through the teaching of basic anatomy and physiology to 5th and 6th grade students in didactic small group and physical activities. AA's potential to cultivate lifestyle change children at the community, state, and national levels is only as effective as its scalability. We report the successful adaption of AA from Stella Middle Charter Academy (Los Angeles, CA) to Salt Lake Arts Academy (Salt Lake City, UT). Volunteer undergraduate and graduate students from UCLA, BYU, and University of Utah Medical School provide great service to their communities while gaining invaluable mentoring experience. AA provides a uniting curriculum and structure, with the flexibility for adaptation to individual site's needs, allowing for creativity to flourish from both students and mentors. Communication via social media has allowed sharing of ideas and experiences across sites. With 5 additional schools in Salt Lake and Utah Counties adopting AA in 2013, including several Title 1 schools, AA is making significant progress to fight obesity one community at a time.Grant Funding Source: The Albert Schweitzer Fellowship and the UCLA Monica Salinas Fellowship
Identification of nicotinic acetylcholine receptor subunit expression in early avian embryos
Authors: Haroon Zoha , Stathos Joseph , Higgins Daniel , Olley John T. , Brauer Philip R. , Reedy Mark V. 
Published: June 2021

Most previous studies on nicotine used relatively high concentrations of nicotine, administered later in development. Using chick embryos as our model system, we have found a single low dose of nicotine (100 nM) administered during early development significantly retarded embryo growth, reduced heart rate, and increased the incidence of defects four days later. It is often assumed that nicotine's teratogenic effects are mediated by nicotinic acetylcholine receptors (nAChRs), whose expression at very early stages of embryonic development has not been thoroughly investigated. The objective was to identify which nAChR subunits are expressed during early avian embryogenesis. We performed RT‐PCR expression analysis for eleven nAChR subunits, including alpha1‐alpha7, alpha9, alpha10, beta3, and beta4, at 24‐, 48‐, 72‐, and 96‐hrs of development. Surprisingly, we find nAChR expression is widespread during early development, which suggests the teratogenic effects of nicotine were mediated by the early activation of nAChRs.Nebraska NIH‐INBRE Program; Nebraska Health and Human Services (LB595); Ferlic Undergraduate Summer Research Program, Creighton University College of Arts and SciencesGrant Funding Source: none current