bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood Pressure Predicts Endothelial Function and Effect of Ethinyl Estradiol in Young Obese and Lean Women
Authors: Adler Tessa E. , Usselman Charlotte W. , Takamata Akira , Stachenfeld Nina S.
Published: June 2021

Obesity, mild hypertension and endothelial function are all predictors of cardiovascular disease in women, and we propose that these factors are interrelated. We hypothesized that obesity and high blood pressure are associated with endothelial dysfunction in young women. Further, we hypothesized that short‐term low‐dose ethinyl estradiol treatment would mitigate this dysfunction. We examined hyperemic responses before and during 30 μg/day oral ethinyl estradiol (EE) treatment for 7 days in 16 healthy women (mean 26 ± 5, 19–35 yrs) with normal (NBP; n=7, MAP range: 78–91 mmHg) or mildly elevated blood pressure (HBP; n=9, MAP range: 95–113 mmHg). We evaluated brachial vasodilatory responses following two stimuli designed to elicit different levels of shear stress: 5‐min occlusion (RH‐FMD), and 3‐min occlusion with ischemic handgrip exercise (IE‐FMD). Body composition did not impact RH‐FMD or IE‐FMD responses. In contrast, Pre‐EE, HBP had lower IE‐FMD responses relative to NBP (8.0 ± 3.5% vs. 12.3 ± 3.2%, respectively; P=0.05). During EE, IE‐FMD increased in HBP (12.8 ± 6.1%; P=0.02) and decreased in NBP (5.6 ± 2.4%, P<0.01). The increase in shear stress (8659 ± 4964 vs. 14753 ± 8189 AUC, s−1; P=0.04) contributed to the increase in IE‐FMD in HBP subjects during EE, while shear stress did not change with EE in NBP (9740 ± 3222 vs. 10564 ± 2984 AUC, s−1; P=0.76). MAP did not predict RH‐FMD responses or associated shear stress, pre‐or during‐EE. Thus, 1) in young healthy women, moderately elevated blood pressure was a predictor of endothelial function whereas obesity was not; 2) EE mitigated endothelial dysfunction associated with elevated blood pressure; 3) the enhanced shear stress stimulus was able to subtle differences in endothelial function where the standard FMD stimulus did not. Because HBP women had only mildly high blood pressure, these data are of particular significance given the new American Heart Association guidelines for hypertension.

Support or Funding Information

Supported by the APS Undergraduate Research Excellence Fellowship; the Paul Titus Fellowship Fund, Dept. Obstetrics Gynecology and Reproductive Sciences, Yale School of Medicine; and the AHA Postdoctoral Fellowship.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effects of a High‐Volume and High‐Intensity Resistance Training Program on Arterial Stiffness
Authors: Pellinger Thomas , Werner Tim , Boutagy Nabil
Published: June 2021

Arterial stiffness has long been regarded as an indicator of disease and is an independent predictor of cardiovascular events. Controversies exist amongst the impact of resistance training protocols on the stiffening process in the major elastic arteries. This study was designed to address some of the controversies.

PURPOSE

To determine the vascular impact of a high‐volume (HV), moderate resistance training program and a high‐intensity (HI), moderate repetition training program on arterial compliance.

METHODS

21 otherwise healthy, male university students with limited resistance training experience (< 6 months) were randomized into one of three groups: 7 control (CO) group (22±3 yrs), 6 HI resistance exercise group (23±3 yrs), and 8 HV resistance exercise group (21±3 yrs). All were subjected to a series of tests including anthropometry, ultrasonography of the carotid artery, applanation tonometry, blood pressure acquisition, and maximal strength assessment. Subjects were instructed to maintain normal dietary patterns throughout the study period. Food consumption was monitored. All subjects in the training groups performed the same 8–10 exercises on training days. Subjects in the HV group trained at 50–70% of 1‐RM with 10–15 repetitions and 2–4 sets per exercise for 3–5 days a week for 12 weeks. Subjects in the HI group trained at 70–95% of 1‐RM with 3–6 repetitions and 2–3 sets per exercise for 3–5 days a week for 12 weeks. Subjects randomized to the control group were instructed to refrain from both cardiovascular and resistance exercise during the study period. Arterial stiffness comparisons were calculated with two‐way ANOVA with repeated measures.

RESULTS

1‐RM significantly increased for squat (52% vs. 25%, p<0.05), bench press (31% vs. 27%, p<0.05) and seated rows (22% vs. 13%, p<0.05) in the HV and HI groups respectively. Carotid femoral PWV did not change in the HI (7.6±2 vs. 8.1±2 m/s, p>0.05), HV (6.3±1 vs. 6.8±2 m/s, p>0.05), and CO (6.7±1 vs. 6.7±1 m/s, p>0.05) groups. Beta stiffness index did not change in the HI (5.9±3.5 vs. 5.7±2.6 U, p>0.05), HV (6.5±1.9 vs. 6.5±2.1 U, p>0.05), and CO (7.2±4.4 vs. 6.4±3.1 m/s, p>0.05) groups.

CONCLUSION

12 weeks of HI and HV training does not appear to augment indices for arterial stiffness in young, adult males.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Internal Carotid Blood Flow Responses To The Diving Response In Humans
Authors: Alsalahi Sultan E. , Fisher James P.
Published: June 2021

The immersion of the face in cold water evokes a powerful autonomic reflex known as the diving response. It is activated primarily by stimulation of the trigeminal nerve (TGS) that innervates the areas around the forehead and cheeks, but its physiological effects are also modulated by secondary mechanisms such as apnoea. The diving response is believed to act to preserve oxygen delivery to the heart and brain. We sought to determine the relative importance of the TGS and apnoea components of the diving response to the regulation of cerebral blood flow.

In 8 young, healthy volunteers (aged 24 ± 3 yr; 2 women), middle cerebral artery velocity (MCAV; transcranial Doppler), arterial blood pressure (Finometer), heart rate (ECG) and the partial pressure of end‐tidal carbon dioxide (PETCO2) were recorded. In addition, internal carotid artery diameter and velocity were measured (ICAV) using duplex Doppler ultrasound, and internal carotid artery flow (ICAQ) calculated. Cerebral vascular conductance (CVC) was calculated as; MCAV or ICAQ/MAP. TGS was evoked by the placement of ice packs on the forehead and cheeks under two conditions; 1) while performing an end‐expiratory breath‐hold (+BH), and 2) while breathing spontaneously (‐BH). The second condition was always undertaken last and its duration was matched to that of the first condition. Data were averaged at baseline (3 min) and at the end of each manoeuvre (last 10 cardiac cycles) and are presented as mean ± SEM.

The apnoea was held for 26 ± 3 s. During combined TGS+BH, mean blood pressure (88 ± 5 vs. 101 ± 4 mmHg), MCAV (67 ± 9 vs. 82 ± 8 cm s−1) and ICAQ (309 ± 42 vs. 386 ± 56 ml min−1) were increased (p<0.05), while MCACVC (0.77 ± 0.11 vs 0.81± 0.08 cm s−1/mmHg) and ICACVC (3.49 ± 0.47 vs. 3.84 ± 0.60 ml min−1/mmHg) remained unchanged (P<0.05), and heart rate tended to decline (71 ± 2 vs. 65 ± 3 bpm; P=0.072). In contrast, during TGS–BH, mean blood pressure increased (87 ± 2 vs. 91 ± 2 mmHg: P<0.01), while MCAV (65 ± 7 vs. 66 ± 7 cm s−1), MCACVC (0.75 ± 0.08 vs. 0.73 ± 0.08 cm s−1/mmHg), ICAQ (304 ± 40 vs. 296 ± 41 ml min−1), ICACVC (3.38 ± 0.48 vs. 3.17 ± 0.47 ml min−1/mmHg) and heart rate (67 ± 4 vs. 66 ± 4 bpm) remained unchanged (P>0.05).

In summary, cerebral blood flow increased when TGS was coupled with an apnoea, but the independent activation of TGS did not elicit an increase in cerebral blood flow. These findings suggest that physiological factors associated with breath holding (e.g., pressor response, CO2 accumulation) make the predominate contribution to diving response mediated‐increases in cerebral blood flow in humans.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Inflammatory Cytokines and Biomarkers in Aging Type 2 Diabetic Rats
Authors: Huo Henry , Harrison Michelle L. , Grotle Ann‐Katrin , Graham James , Stanhope Kimber L. , Havel Peter J. , Stone Audrey J.
Published: June 2021

Aging, type 2 diabetes mellitus (T2DM), and cardiovascular disease are all associated with systematic low grade inflammation. Accordingly, these conditions alter circulating concentrations of cytokines involved in inflammation and vascular function. Recent studies suggest that these same cytokines may contribute to the sensitization of group III and IV afferents, which are involved in evoking the exercise pressor reflex during skeletal muscle contraction. The purpose of this study was to determine the concentrations of cytokines involved in inflammation and vascular function in aging T2DM rats. To accomplish this we analyzed blood samples drawn from UC Davis T2DM rats at 4 months (BW: 549 ±29 g, glucose: 337±147 mg/dl, HbA1c: 7.4±0.6%, insulin: 5129±3799 pg/ml), 8 months (BW: 546±77 g, glucose: 549±46 mg/dl, insulin: 288±416 pg/ml), and 12 months (BW: 512±144 g, glucose: 551±57 mg/dl, HbA1c: 11.9±2.4%, insulin: 436±167 pg/ml) of age. We used healthy, adult (CTL) Sprague Dawley rats (BW: 465±18 g, glucose: 200±14 mg/dl, HbA1c: 4.7±0.1%, insulin: 1692±1422 pg/ml) as controls. We analyzed serum samples, to determine the concentration of circulating IL‐1β, IL‐10, IL‐4, and insulin, using rat cytokine/chemokine and adipokine multiplex kits (EMD Millipore)and a Bio‐Plex 200 instrument. We found that the concentration of the pro‐inflammatory cytokine IL‐1β gradually, although not significantly, increased in T2DM rats as they aged compared to CTL rats (4 mo: 49±18 pg/ml, n=4; 8 mo: 72±48 pg/ml, n=9; 12 mo: 71±24 pg/ml, n=6; CTL: 38±12 pg/ml, n=6). The concentration of the anti‐inflammatory cytokine IL‐10 decreased in T2DM rats as they aged compared to CTL (4 mo: 542±454 pg/ml, n=4; 8 mo: 112±168 pg/ml, n=8; 12 mo: 467±264 pg/ml, n=6; CTL: 1289±527 pg/ml, n=4; p<0.05). The concentration of the anti‐inflammatory cytokine IL‐4 appears to be more variable over time in T2DM rats as it decreased at 4 mo and 8 mo of age and then increased at 12 mo of age (4 mo: 18±15 pg/ml, n=4; 8 mo: 8±12 pg/ml, n=8; 12 mo: 49±7 pg/ml, n=5; CTL: 25±21 pg/ml, n=6; p<0.05). These results suggest that circulating concentrations of pro‐inflammatory and anti‐inflammatory cytokines are altered in aging T2DM rats and they may be increased or decreased depending on duration of the disease. Additionally, these changes in inflammatory cytokines may play a role in exaggerating the exercise pressor reflex in aging T2DM rats.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A Role for Hypoxia‐inducible Factor 1‐alpha (HIF1a) Signaling in Suppressing Synaptic Plasticity and Spatial Memory During Intermittent Hypoxia
Authors: Nwakudu Chinwendu U. , Barnard Jasmine , Khuu Maggie A. , Garcia Alfredo J.
Published: June 2021

Although HIF1a signaling is commonly identified as a mediator of positive homeostatic responses to hypoxia, during intermittent hypoxia (IH), a primary effect of sleep apnea, HIF1a signaling can cause oxidative stress in the body. IH‐dependent oxidative stress can lead to pathophysiological changes throughout the nervous system associated with sleep apnea. The objective of this study is to determine whether HIF1a signaling during IH opposes or facilitates IH‐dependent suppression in synaptic plasticity and spatial memory. Both adult wildtype mice (WT) and mice heterozygous for HIF1a (HIF1a+/−) were either unexposed (control) or exposed to chronic intermittent hypoxia (CIH) for 10 days. Hippocampal brain slices (350 microns thick) were prepared from mice of each group. Extracellular recordings of the field excitatory postsynaptic potential (fEPSP) were made before and after the induction of long‐term potentiation (LTP) in area CA1. While LTP occurred in brain slices of WT from both groups, the magnitude of LTP was larger in the control group (164±6% of baseline, n=5) as compared to the CIH group (115±10% of baseline, n=5). LTP in the brain slices from the HIF1a+/− exposed to CIH was 152±10% of baseline (n=5), which was greater in magnitude compared to WT LTP in the CIH group. Ongoing experiments suggest spatial memory in the Barnes Maze is unaffected by CIH in HIF1a+/−. These findings show that IH‐dependent HIF1a signaling disrupts hippocampal synaptic plasticity and spatial memory, which may contribute to cognitive impairment associated with sleep apnea.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Exercise training protects against aging‐induced cognitive dysfunction via activation of hippocampal PGC‐1α/FNDC5/BDNF pathway
Authors: Belviranli Muaz , Okudan Nilsel
Published: June 2021

Aging process is associated with decreases in cognitive functions, but this decrease may be reversed by regular exercise. However, the molecular mechanisms responsible from this processes remains unclear. Here, we aimed to investigate the impacts of exercise training on cognitive performances such as locomotion, anxiety‐related behavior, learning and memory and hippocampal PGC‐1α, FNDC5, BDNF and other cognition‐related gene expressions and hippocampal FNDC5 and BDNF protein expressions in both young and aged rats. Animals were separated into four groups as regards to age (young vs. aged) and training status (control vs. exercise training). Voluntary exercise training was performed for 90 d, and several behavioral assessments were applied. Following behavioral assessment, hippocampus tissues were obtained for analysis of gene expression of PGC‐1α, mTOR, ERK, SIRT1, cFOS, NF‐κB, ARC and FOXO and gene and protein expressions of FNDC5 and BDNF. Locomotor activity and spatial memory were lower but anxiety scores were higher in the aged rats (P < 0.05). Exercise training enhanced these variables in both young and aged rats (P < 0.05). Hippocampal BDNF, FNDC5, PGC‐1α, mTOR, ARC, cFOS, ERK, SIRT, and FOXO expressions decreased, but NF‐κB expressions increased in aged rats (P < 0.05). Exercise training ameliorated these variables in both young and aged rats (P < 0.05). Similarly, hippocampal BDNF and FNDC5 protein expressions were lower in the aged rats and exercise training elevated them in both young and aged rats (P < 0.05). According to these results, we concluded that aging‐induced cognitive dysfunction is mainly associated with decreased hippocampal expression of PGC‐1α, FNDC5, and BDNF and exercise training improves cognitive functions via activating these molecules in the hippocampus.

Support or Funding Information

This work was supported by the Selcuk University Scientific Research and Project Coordinatorship (project number: 15401171).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cyclosporin A Induces Hypertension via a Cholesterol‐ and ENaC‐Dependent Mechanism
Authors: Linck Valerie , Zou Li , Zhai Yu‐Jia , Eaton Douglas C. , Ma He‐Ping
Published: June 2021

Hypertension related to the use of immunosuppressive drugs, particularly cyclosporin A (CsA), presents one of the major problems in the management of transplant recipients. Our recent studies suggest a hypothesis that CsA may cause hypertension by stimulating the renal epithelial sodium channel (ENaC) via a pathway associated with elevated intracellular cholesterol (Cho). To further determine the mechanism, we performed confocal microscopy and patch‐clamp experiments using cultured cortical collecting duct (CCD) principal cells and measured the blood pressure in mice. Confocal data show that CsA and Cho increased both the length of microvilli of CCD cells where ENaC is located and the levels of phosphatidylinositol‐4,5‐bisphosphate (PIP2) in microvilli. Conversely, inhibition of Cho synthesis with lovastatin decreased the levels of PIP2, a well‐known ENaC activator. Patch‐clamp data shows that Cho increased ENaC activity in a PIP2‐dependent manner. Interestingly, CsA elevated the blood pressure in mice and the elevation was abolished by either inhibition of Cho synthesis with lovastatin or blockade of ENaC with amiloride. These results suggest that CsA increases the blood pressure of mice by stimulating ENaC via a pathway associated with the elevation of intracellular Cho and PIP2 in the principal cells of CCD. However, it remains to be determined whether statins or amiloride can be used for the treatment of CsA‐induced hypertension.

Support or Funding Information

(Supported by NIH R01DK100582 to H.M.)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Environmental Factors Influence α‐synuclein Transport In The Gut‐brain Axis In A Rodent Model Of Parkinsonism
Authors: Bove Cecilia , Anselmi Laura , Travagli R. Alberto
Published: June 2021

In recent years, idiopathic Parkinson's disease (PD) has been hypothesized to be triggered by the gastrointestinal (GI)‐mediated transport of environmental pathogens; these pathogens then travel retrogradely to the central nervous system in a bottom‐up fashion via the vagus nerve, and induce the typical degeneration of dopaminergic neurons of the substantia nigra pars compacta (SNpc). The presence of misfolded α‐synuclein in SNpc is the characteristic histological hallmark of PD. We have shown previously that oral co‐administration of subthreshold doses of paraquat (1mg/kg) and lectins (0.05%w/v) causes GI dysmotility and may be implicated in PD's etiology.

In the present work we aimed to further characterize the effects of this model of Parkinsonism on the gut‐brain axis. Rat groups were gavaged with i) 1% sucrose (control); or ii) 0.5% lectins + paraquat, 1 mg/kg (200μl for 7 days). Motor behavior, and gastric motility/tone were measured 14 and 30 days post‐gavage, via strain gauges sewn to the anterior gastric surface. At the end of the experiment the GI tract and the brainstem were extracted and processed for immunohistochemistry. Organotypic cultures of stomach and small intestine of naïve rats were incubated up to three days in a culture medium containing 0.5% lectins prior to immunohistochemistry. Motor behavioral tests (vibrissae and stepping tests) revealed initial small, albeit significant, motor dysfunctions in the tested rats at 2 weeks post treatment (N=10), the motor dysfunctions were more pronounced at 4 weeks post treatment (N=10). Levodopa (4 mg/kg b.i.d.) re‐established normal motor behavior (N=12).

Organotypic cultures revealed that lectins were present in NOS‐ and in NeuN‐ immunoreactive myenteric neurons, as well as in nerve fibers, likely of extrinsic vagal origin. As reported previously (DDW 2017), this experimental model is associated with gastric motor impairment. Tissues from the stomach, small and large intestine of these rats revealed the presence of misfolded α‐synuclein in 40–60 % of myenteric neurons. The presence of α‐synuclein was noted in neurons of the dorsal motor nucleus of the vagus and the SNpc at two weeks post treatment. At four weeks post treatment, the expression of α‐synuclein was more pronounced, and was accompanied by a significant loss of tyrosine‐hydroxylase immunoreactive neurons of the SNpc.

The data suggest that prolonged oral exposure to subthreshold doses lectins and paraquat induces a Parkinsonian phenotype that mimics the prodromal GI dysfunctions and α‐synucleopathy progression in the gut‐brain axis observed in patients.

Support or Funding Information

NIH DK 55530

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
RBM20 Deficiency Postpones Skeletal Muscle Regeneration After Injury and Promotes Fibrotic Tissue Formation
Authors: Rexiati Maimaiti , Sun Mingming , Guo Wei
Published: June 2021

Introduction

RNA binding motif 20 (RBM20) is a splicing factor with specific expression in striated muscles. It regulates muscle gene splicing and expression. Previous study indicated that RBM20 is associated with myoblast differentiation in C2C12 cell cultures. With higher expression of RBM20, myoblasts were highly differentiated. In this study, we evaluated whether RBM20 regulates muscle differentiation and regeneration in rat muscle injury model.

Methods

Muscle injury model was made with 9‐week‐old male wild type (WT) and RBM20 knockout (KO) rats by injecting 0.5ml of 1.2% barium chloride into tibialis anterior and normal saline as control. Tibialis anterior muscles are harvested at 18hours, 3days, 5days, 7days, 14days, and 1month post‐injury (n=5 per time point) and used for western blot, histological and immunofluorescence analyses.

Results

Our results indicated that muscle mass and the regenerating fiber numbers were not significantly different between WT and KO injury during the whole process of regeneration. However, mean cross‐sectional area (CSA) of the regenerating myofibers after 7‐day post injury was significantly smaller in KO when compared to WT, indicating delayed muscle regeneration after injury in RBM20 KO. Further, we found that fibrotic area and TGFβ1 signaling were significantly increased in KO as compared to WT after 14‐day post injury. To test whether RBM20 involves muscle differentiation, we evaluated the expression of Pax7, MyoD, and Myogenin at 5 and 7‐day post injury, we found no changes of these transcription factors at 5 days, but MyoD was significantly reduced at 7 days in KO muscle compared to WT. Interestingly, we found that RBM20 expression was increased with post injury muscle regeneration from 18 hours to 1 month.

Conclusion

RBM20 is a novel factor that promotes muscle regeneration after injury and protect from fibrotic tissue formation.

Support or Funding Information

This work was supported by the NIFA‐USDA 1009266, National Institutes of Health NIGMSP20GM103432, AHA BGIA and Faculty‐Grant‐in‐Aid from University of Wyoming.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Dynamic Assessment of Ca2+ Sensitivity of Isometric Force in Intact Airway Smooth Muscle Using Phase Loop Plots
Authors: Osorio Sara , Han Young , Sieck Gary
Published: June 2021

A transient elevation of cytosolic Ca2+ concentration ([Ca2+]cyt) triggers a force response in excitation‐contraction coupling. The Ca2+ sensitivity of muscle reflects the relationship between [Ca2+]cyt and force, and in skeletal and cardiac muscle is often defined as the [Ca2+]cyt at which 50% force is generated (ED50). In smooth muscle, Ca2+ sensitivity has been assessed as the ratio of peak force to peak cytosolic [Ca2+]cyt. However, this conventional measurement overlooks the dynamic nature of Ca2+ regulation of force generation. In the present study, in order to provide a dynamic index of Ca2+ sensitivity in airway smooth muscle (ASM), we simultaneously measured [Ca2+]cyt and force and determined their temporal dependence using a phase loop plot. We examined the phase loop plot assessment of Ca2+ sensitivity in ASM under the condition in which the conditional assessment indicated an increase (Calyculin A treatment) in Ca2+ sensitivity. Intact ASM strips were isolated from porcine tracheas obtained from local abattoir. ASM strips were loaded with Fura‐2 AM (Ca2+ fluorescent indicator) and stimulated using 1 mM ACh. Isometric force and [Ca2+]cyt responses were simultaneously measured using a Guth Muscle Research System. ASM strips were exposed to Calyculin A (phosphatase inhibitor; 100 nM for 10 min), which was previously reported to alter static Ca2+ sensitivity. Phase loop plots were calculated from simultaneous [Ca2+]cyt and force responses. The extent of rMLC phosphorylation was determined at different time periods after ACh stimulation using Phos‐tag SDS‐PAGE (SuperSep Phos‐tag; Wako Pure Chemical Industries, Ltd.) and Western blotting. Calyculin A increased ACh‐induced isometric force in ASM strips, but it had no effect on the amplitude of evoked [Ca2+]cyt transients. These results suggested that Calyculin A increased static Ca2+ sensitivity. However, the phase loop plots showed no significant shift in dynamic Ca2+ sensitivity with Calyculin A. These results indicate that the phase loop plot provides a valuable tool to assess dynamic Ca2+ sensitivity of isometric force generation in ASM, which better reflects the complex process of excitation‐contraction coupling in smooth muscle. These results further indicate that dynamic Ca2+ sensitivity of force generation in ASM is independent of rMLC phosphorylation.

Support or Funding Information

Supported by NIH grant HL126451 (GCS)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Development of a Rubric to Evaluate Student Reflection Essays in a Clinical Physiology Course
Authors: Strosdahl Coleman C. , Anderson Lisa Carney
Published: June 2021

Reflection as a learning technique may be an important strategy for long‐term retention of information. In this study, investigators used a descriptive design to analyze student reflective writings in a two‐course clinical physiology series. In this course series, students completed multiple‐choice exams, first as individuals and second in inter‐disciplinary student groups (biology, physiology, nursing anesthesia and biomedical engineering). Student groups must discuss each question until the group reaches a consensus on the answer. Following the exam students write reflection essays on three exam questions of their choosing. For this assignment, students are encouraged to pick questions that were particularly difficult or that inspired a lot of group discussion. Students were instructed to write about their thought process for choosing their answer and how the group discussion influenced how they thought about the question. The course instructor, also an investigator, collected student writings over a two‐year period, compiled and de‐identified the essays and organized essays according to exam and semester.

The course instructor and a student co‐investigator worked as a team to analyze student writings for levels of reflection. First, the investigators adapted a previously published reflection rubric (Hoffman, Shew, Vu, Brokaw & Frankel, 2016) using student writing from the academic year 2015–2016. The investigators analyzed writings separately using the rubric and then met to discuss the essays, reconcile their individual ratings, and revise the rubric as inconsistencies were discovered. In this way, the original rubric was tested and refined. The adapted rubric is a check list of desired essay components: good writing (spelling, grammar, focus), individual reflection, articulation of group process, use of references and insights about future learning. Once a final version of the rubric was agreed upon, the revised reflection rubric was used to evaluate student writings from the academic year 2016–2017 for inter‐rater reliability. There was no correlation between student exam scores and ratings of reflection; this was an unexpected result.

Currently the rubric is being used in the 2017–2018 course series to guide student reflection writings.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Morphological characteristics of laboratory rat's primary and secondary lymphoid organs beyond water‐soluble silicon consumption in repeated studies.
Authors: Sergeeva Valentina Efremovna , Gordova Valentina Sergeevna
Published: June 2021

Recently we have shown that water‐soluble silicon compounds induced certain morphological changes in different lymphoid organs of laboratory rodents. Here we generalized our results received in timeframe from 2011 until 2014.

The primary (thymus) and secondary (spleen, Peyer's patches) lymph organs of 6 weeks old white outbred male rats were investigated. The control animals (group 1; n=10) received standardized drinking water ad libitum, the experimental rats (group 2; n=10) got ad libitum the same water containing sodium metasilicate (10 mg/liter silicon content) during 2 months. First study from 2011 was repeated in 2012 and in 2014. All procedures with rats were performed in accordance with the prevailing guidelines for animals care. The thymus, spleen, Peyer's patches were isolated immediately after decapitation, fixed in 10% formalin, and embedded in paraffin. 5μm thick sections were stained with hematoxylin‐eosin and toluidine blue. Photomicrographs from lymph organs were captured with help of light microscope MIKMED 5 under ×1000 magnification and collected for further morphometric evaluation with SigmaScan Pro 5.0 software. The mean areas of the secondary lymphoid nodules were measured in five fields of view with fixed area per animal per group. Standard error of the mean (SEM) were calculated for all means.

The comparative morphometric analysis in 2011 revealed that after two month of treatment the germinative center area of splenic and small intestine's secondary lymph follicles in experimental group were 1,2 times larger (p < 0,05), than in control group.

The administration of water‐soluble silicon compounds probably forced the physiological involution of thymus by depletion of lymphocyte amount in thymic cytoreticulum. All these data were confirmed in repeated experiments in 2012 and 2014. Moreover, we received the comparable data from thymic mast cell reaction to the silicon consumption in all serial experiments in 2011, 2012 and 2014: ortochromatic mast cells appeared and metachromatic mast cells underwent to degranulation.

In 2011, 2012 and 2014, we also noticed, that 20% of experimental animals, which received water‐soluble silicon compounds, had thymic lymph follicles. Known, that such structures appear in the thymus during autoimmune diseases.

Our multi‐annual repeated experiments demonstrated that silicon from drinking water probably can influence humoral immunity processes and this fact cannot exclude the role of water‐soluble silicon compounds in the development of autoimmune diseases.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Understanding the development of variable craniofacial phenotypes caused by altered methylation affecting Wnt9b in A‐strain mice
Authors: Green Rebecca M. , Leach Courtney L. , Schmidt Eric , Diewert Virginia , Marcucio Ralph S. , Hallgrimsson Benedikt
Published: June 2021

Variable clinical presentation is common in many structural birth defects, two children with the same genetic mutation often have different clinical presentation. Therefore, understanding the developmental origin of such variability is of fundamental importance to developing patient targeted treatment, or precision medicine. A/WySn mice are genetically identical, inbred mice, but about 20% of them develop cleft lip and palate. This has been linked to loss of methylation at an IAP retrotransposon near Wnt9b (Wnt9bIAP). Using a newly developed protocol for generating RNA and DNA as well as a 3D microCT scan that can be used to quantify shape, we show that loss of methylation at this locus directly correlates with facial shape in precleft embryos. Line1 methylation is unaffected in embryos with abnormal Wnt9bIAP methylation levels. Wnt9bIAP methylation levels are bimodal, but continuous, as are facial shape, Wnt9b and Axin2 levels. We use all of these factors to build a model of how multiple continuous bimodal inputs lead to a discontinuous phenotype (clefting). We also determine how this model relates to underlying changes in the cell biology in the affected tissue.

Support or Funding Information

NIH R01 2R01DE019638 to RSM and BH. NSERC 238992‐17 to BH. Alberta Children's Hospital Research Institute Fellowship to RG.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Tooth Wear Rates for Propithecus diadema in the Fragmented and Pristine Forests of Tsinjoarivo, Madagascar
Authors: Heffernan Katie SusAnn , Samonds Karen , Irwin Mitchell
Published: June 2021

Primate teeth wear through time in response to their environment. This change in topography has the potential to affect nutrient absorption if mastication is less effective at reducing food particle size. Lemurs exhibit a broad range of diets and life history strategies, as well as adaptations for surviving in an unpredictable environment. Previous studies on diademed sifakas (Propithecus diadema) in Tsinjoarivo, Madagascar show that groups in fragmented forests eat a less diverse diet and use fallback foods year‐round, while sifakas living in pristine forests eat less preferred foods only during the lean season. Groups persist in fragments, yet these dietary changes may increase rates of tooth wear and have consequential deleterious effects on their lifetime fitness and population viability.

Previous studies examining tooth wear over time have mainly focused on changes in slope, angularity, and surface relief, but frequently these studies use individuals with estimated age. By examining known‐aged individuals through time, specific patterns of dental wear can be correlated to variation in diet, sex, age, and habitat differences. In this study, dental molds of 75 individuals from 10 groups of Propithecus diadema were taken over a 15‐year period in both the fragmented and pristine forests of Tsinjoarivo. Tooth casts were scanned and analyzed with Geographic Information System (GIS) software to obtain values for relief index, slope, and angularity. All three of these factors decreased with age and show some significance among specific groups of sifakas but results show no effect of overall forest type on rates of tooth wear. Thus, while forest disturbance has demonstrated impact on diet, tooth wear did not accelerate as predicted. Future research should incorporate additional tooth wear data as these known‐aged lemurs advance in years, and examine the functional consequences of tooth wear more directly.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
EMBRYO‐FORM PROJECT : STUDY OF THE HUMAN SPINAL CORD VASCULAR SYSTEM
Authors: Barbier Dominique , Renard Yohann , Fauvel Marc , Perez Manuela , Labrousse Marc , Braun Marc
Published: June 2021

INTRODUCTION

We proposed to review and illustrate the overall venous human spinal cord vascular embryonic organization using the latest current 3D‐reconstruction possibilities “The Embryo‐form project”

MATERIAL & METHOD

High résolution numerised microscopic continuous sections (10 to 20 m) from Carnegie stage XIX to XXIII human embryo were used. Specific image treatment was the following : binarisation‐ thresholding‐labellisation, rigid shifting, median filtration (cubic matrix) (resolution 10mm/pixel) ; DICOM format images are exported for post‐treatment process. Angiographic rendering was obtained thanks to the Eosine/hematoxylin red cell fixation within the vessels.

This gathering brought together 20 human embryos prepared in serial histological sections, collected during the mid 50's. We also get access to the Carnegie's embryos collection thanks to her curator Miss E Lockett. 20 Embryos were digitalized with a flatbed scanner at 2400 DPI resolution

RESULTS

At first step, we confirmed the embryonnic status relatively to the Carnegie classification in assessing the cochlear canal orientation. The evolutive morphology of the brain stem primitive network is presented ; at stage XIX, the initial longitudinal veins are separated from the caudal plexus. During the next stages, we demonstrate how they connected to transverse pial anastomoses.

The next period (i.e the early and late post‐embryonic period) show these intrinsic pial veins lying between the arteries and the brain surface leading to a progressive simplication pattern. During the stages XX to XXIII, we present the changing morphology of the X, XI and XII nerve ganglion venous plexus. These organisations are compared to the Padget and Streeter works.

CONCLUSION

We present the preliminary work of the cervical spinal cord venous embryogenesis using 3D and angiographic rendering at the early post‐embryonic stages

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effect of Hobo Transposon Excision on DNA repair in Drosophila melanogaster
Authors: Miller Anna , Saville Ken
Published: June 2021

As the repository of genetic information, it is critical to organisms that DNA damage is repaired quickly and with high fidelity. When DNA damage is improperly repaired, it may cause diseases such as cancer and severe combined immunodeficiency. DNA can be mutated by numerous agents both external and internal. One internal source of DNA damage is from the transposition of transposable elements, including the P and hobo elements. Transposable elements “jump” out from one section of the DNA and reinsert into another, leaving double strand DNA breaks at the excision site. Hobo excisions are preferentially repaired by nonhomologous end‐joining, NHEJ. DNA repair and transposable elements themselves can be studied in Drosophila melanogaster. This study looked at the hobo on P, or HOP, element. The P element is located inside of the Hobo element; HOP8 is nonautonomous and needs hobo transposase to be supplied in trans. Curly winged, glazed eye female flies that have an inducible source of hobo transposase were crossed with HOP8 male flies and heat shocked to trigger transposition, leaving a double strand DNA break requiring repair behind. The resulting mosaic eyed male flies were then crossed with wild type female flies because mosaic eyes mark meiotic recombination in the P element. Female flies with white eyes indicating that hobo transposition occurred, were collected and stored in a freezer. Experiments are underway to determine the original location and new insertion sites of hobo using inverse PCR to further understand DNA repair.

Support or Funding Information

Albion College Foundation for Undergraduate Research, Scholarship, and Creative Activity (FURSCA)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Association of Oxidative Stress with Polycystic Ovarian Syndrome in Oman: A Case‐Control Study
Authors: Sulaiman Maha AH. , Al‐Farsi Yahya M. , Al‐Khaduri Maha M. , Saleh Jumana M. , Waly Mostafa I.
Published: June 2021

Background

Previous studies in Euro‐American populations have shown that women with polycystic ovarian syndrome (PCOS) have increased levels of serum oxidative stress markers. In the Arab region, there is noticeable lack of research of the association between oxidative stress and PCOS.

Objective

This study aims to compare socio‐demographic, clinical characteristics and oxidative stress indices between women diagnosed with PCOS and non‐PCOS women.

Methods

This hospital based case‐control study was conducted among women aged 16–49 years. The study included 51 women diagnosed with PCOS (as per Rotterdam 2003 criteria) and 45 control women who were known not to have PCOS. Serum blood samples were collected to measure biomarkers of oxidative stress including glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), and total antioxidant capacity (TAC) using commercially available kits.

Results

Reduced GSH levels (P= 0.006) were significantly lower among PCOS women compared to non PCOS women. GR and GPx activity levels showed higher trends in women with PCOS compared to non PCOS women and the difference was significant for the GPx activity (P= 0.04). PCOS women also showed lower TAC levels (P= 0.08) than the control group with no significant difference between the two groups.

Conclusion

The study provides a supportive evidence for the association between oxidative stress and PCOS among Omani women. Oxidative stress might play a role in pathogenesis of PCOS, so these parameters may be suggested as diagnostic markers for early diagnosis and screening of high risk groups.

Support or Funding Information

Sultan Qaboos University

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Different classes of RNA require distinct Mex67 paralogs for processing and nucleocytoplasmic export in trypanosomes.
Authors: Obado Samson , Chait Brian , Field Mark , Rout Michael
Published: June 2021

The nuclear pore complex (NPC) is at the center of nucleocytoplasmic transport as well as many aspects of gene regulation. A series of steps involving the NPC enable the translation of genes to proteins, starting with the initiation of transcription, through quality control and transport through the NPC, to finally the remodeling of ribonucleoprotein (RNA‐protein) complexes on the cytoplasmic face of the NPC. We recently described the architecture of the trypanosome NPC. Notably absent from the cytoplasmic face of the trypanosome NPC are a host of anchored RNA export and remodeling proteins found in the opisthokont (yeast and human) cytoplasmic RNA export platform. This pointed to a significantly different mode of RNA export and processing in trypanosomes. An evolutionarily conserved group of proteins termed nuclear export factors (NXFs) are responsible for the transport of bulk mRNA from the nucleus to the cytoplasm for translation into proteins, as well as aiding ribosomal subunit export. There is a single major nuclear export factor in yeast (Mex67 or NXF1 in metazoa); although metazoans have additional tissue‐specific NXF variants. All variants of NXF form a heterodimer with Nuclear Transport Factor 2 (NTF2)‐Like Export Factor 1 (NXT1 in humans or Mtr2 in yeast), which facilitates NPC localization and translocation. Orthologs of both NXF and NXT have been identified in trypanosomes, termed TbMex67 and TbMtr2 respectively. Our data suggests that there are in fact three Mex67 paralogs in trypanosomes. We provide evidence strongly indicating they have crucial differing functions. As RNA processing and export are highly integrated events, the export pathway is likely an important step in the regulation of gene expression in trypanosomes.

Support or Funding Information

NIAID Exploratory/Developmental Research Grant 1R21AI096069 (to MR)

NIGMS GM103314 (to BC), GM103511 and GM109824 (to MR and BC);

Wellcome Trust grant 082813/Z/07/Z (to MF and MR).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mutagenesis of the Human α‐Galactosidase A Active Site, Dimer Interface, and Glycosylation Region
Authors: Stokes Erin
Published: June 2021

Fabry disease is an X‐linked lysosomal storage disorder caused by the deficiency of the enzyme, α‐galactosidase A, which results in the accumulation of the lipid substrate. This accumulation results in obstruction of blood flow in patients and early demise at approximately 40–60 years of age. Currently approved enzyme replacement therapy using recombinant human α‐galactosidase A improves patient symptoms but storage of the toxic enzyme substrate remains in the brain and other affected organs. The structure of α‐galactosidase A has been previously determined to be a homodimer with six N‐linked glycosylation sites, and the catalytic mechanism determined to be a ping pong bi bi with the second substrate being water. The purpose of this research is to generate a more efficient enzyme replacement therapy alternative. A more efficient therapy was investigated utilizing Pichia pastoris, as well as site directed mutagenesis of the human enzyme. Three locations on the structure of α‐galactosidase A protein were targeted for mutation: the active site; the dimer interface; and the hydrophobic loop between the active site and the third glycosylation site. Viable candidates for further study into a therapeutic were determined based on catalytic efficiency (kcat/Km), thermostability, and possible glycosylation independence. Three mutations were identified, M208E (hydrophobic loop), W277C (dimer interface), and Y207W (active site) to be of potential therapeutic significance.

Support or Funding Information

NIH SBIR Grants and Royalty Income From Patents

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Assessing efficiency of the New England Biolabs Q5® site‐directed mutagenesis kit to produce a library of aminoglycoside N‐acetyltransferase mutants
Authors: Macias Jennifer , Pham Olivia , Vaca Alexis , Pennings Pleuni , Kuhn Misty L.
Published: June 2021

Our aim was to construct a library of 63 rationally designed aminoglycoside N‐acetyltransferase mutants in a high‐throughput manner using the Q5® site‐directed mutagenesis kit from New England BioLabs Inc. Per the manufacturer's recommendation, we used their NEBaseChanger™ tool to design primers for each mutant and followed their Quick Protocol. Since we wanted to use our 96‐well thermocycler with six different gradient optimization blocks, some of the recommended annealing temperatures were adjusted by ± 0.5°C. Qualitatively, we found that this change did not have a significant impact on obtaining amplified products for most of our samples. We observed 49 PCR products at the correct size of ~6 kB in our first reaction and proceeded with the subsequent steps of the manufacturer's protocol. One colony from each mutant was then sent for sequencing to save funds. Of the 49 constructs tested, 32 were correct, which resulted in a 65% success rate from a single reaction. We sent one additional colony from the remaining 17 constructs and obtained 7 additionally correct mutants, for a total of 39/49 correct constructs. The remaining 10 mutants from this first amplification showed products with premature stop codons, wild‐type template DNA, or incomplete amplification products. Therefore, we performed additional troubleshooting reactions to obtain the remaining 24/63 mutants. We found that adjustments of up to 3°C from the recommended annealing temperature and additional sequencing attempts were required to obtain the remaining mutants. While the Q5 kit is user‐friendly and straightforward, we found it was not as cost‐effective as we had hoped and required several rounds of troubleshooting to complete our library.

Support or Funding Information

This work was supported in part by a Ken Fong Fund Grant (to MLK and PP). Additional support was provided by the Genentech Foundation and NIH MBRS‐RISE: R25‐GM059298 (to OP).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.