bluuebunny/crossref_metadata_2025_split huggingface dataset:
SPARC: Fecobionics Simulated Defecations in Pigs
Authors: Wang Mengjun , Gregersen Hans , Sun Daming , Han Ling , Kassab Ghassan 
Published: April 2020

Objective. We have developed an integrated Fecobionics device to assess pressures, orientation and bending simultaneously during defecation. This study assessed the feasibility of the Fecobionics device in pigs.Methods. Ten Yorkshire pigs (male, 50–60kg) were divided into groups that was euthanized immediately after the experiment (acute group, n=5) or lived for 2 weeks before the pigs were euthanized (chronic group, n=5). Fecobionics is a bendable probe that contains pressure sensors, motion processing units (MPUs), and electronic circuits. The probe was 13cm long, 13mm OD and contained a bag for distension. The pigs were lightly restrained in a sling. The device was inserted manually through an anoscope into the rectum within half hour after the pig had a normal defecation. The bag was filled with 20–50 ml of saline to provide an urge to defecate. Behavior and signs of discomfort was evaluated during and after the defecation. Pressures, orientation and bending data were collected during defecation. Both the rectum and the anal canal were excised after euthanization for mucosal gross morphological observation and histological examination. Devices were tested after the expulsions for any damage to the electromechanical system, the core and bag.Results. The pigs paid little attention to device insertion if they were distracted by food. Often the pigs became a bit agitated after eating and defecated the device at this point. The device was defecated from few minutes up to 1h after insertion (average 12min). The pressure sensors at the two ends and inside the bag showed simultaneous pressure increase when the pigs contracted the abdominal muscle. The defecation pressure was usually in the range 80–100cmH2O if the pig was not agitated. Device bending was less than 20 degrees during defecations, indicating that the pig does not exhibit an anorectal angle like humans. Fecobionics was slowly pushed out in 10–40 seconds, often with the front hanging from the anus for some time before being dropped. The recovered devices had intact surfaces without exposed electronics. In two cases the bag had a small leak. One device stopped working after being defecated and had a broken wire, likely due to damage when it dropped to the floor. Mucosal damage, bleeding and inflammation were not found in gross morphological observation and histological examination in the acute or chronic groups.Conclusions. Fecobionics is a safe device providing novel defecatory measurements under physiological conditions.Support or Funding InformationNIH SBIR phase 1 grant R43DK112543 and NIH SPARC OT2OD025308
Analyzing the effects of past, present, and future water consumption through analog mapping
Authors: Arellano Denisse , Wang Zhihua 
Published: April 2020

The average amount of water usage per capita is 70 gallons per day. Individuals do not often consider their daily water consumption. Model simulations are useful in predicting future water consumption scenarios. Simulation models consist of the different relationships of elements and their correspondence to one another. On the other hand, analog mapping is being used more frequently to visually express and examine the differences in data throughout multiple physical geographical locations. In this study we determine the similarities between water usages across various cities. The cities that are compared are along the continental United States of America regardless of their climate variability. Historical water usage from 50 years ago, water usage habits as the current phenomenon, and projected water usage scenarios in a future 50 years from now are carefully analyzed. This study combines water usage predictions along with analog mapping to evaluate water‐availability and water‐usage. Results from this study can be used to assess the impact of unregulated water usage and the risks of water depletion. The interconnection of both water simulation models as well as analog mapping can help prompt distinct water usage perspectives in addition to alternative methods of communication. Further research can help evaluate alternative development scenarios.Support or Funding InformationNSF LEAP Scholars Program
Mechanisms underlining excitatory synaptic plasticity in the Nucleus Tractus Solitarii following Cardiovascular Deconditioning
Authors: Lima-Silveira Ludmila , Hasser Eileen M. , Kline David D. 
Published: April 2020

The nucleus tractus solitarii (nTS) is a critical central region for autonomic control and integration of cardiovascular reflexes. Neuroplasticity in nTS contributes to several cardiovascular dysfunctions. Our previous data showed that Hindlimb‐unloading (HU), a well‐established model of cardiovascular deconditioning in rats, increases glutamatergic neurotransmission yet reduces the excitability of nTS neurons. In this study we aimed to investigate the mechanisms underlining these alterations. For this purpose, stainless wire rings were placed in the tail of male Sprague‐Dawley rats (3 weeks). After one week of recovery the rings was connected to a suspension apparatus and rats were suspended at an angle of 30–35° for two weeks with free access to food and water. Control animals were maintained in normal postural conditions. After the HU protocol, coronal brainstem slices were generated and the whole‐cell patch clamp technique was performed to evaluate the synaptic neurotransmission and electrophysiological properties of nTS neurons. Compared to control rats, HU increased the amplitude of excitatory postsynaptic currents evoked by afferent tractus solitarii stimulus (TS‐EPSC). The addition of a NMDA receptor antagonist (AP5, 10 μM) significantly reduced TS‐EPSC amplitude in HU but not controls. Despite the increase in glutamatergic inputs, the neurons of HU vs control rats are hyperpolarized and have decreased excitability. The block of both NMDA and non‐NMDA (NBQX, 10 μM) glutamatergic receptors did not affect these parameters. However, in the presence of a GABAA receptor antagonist (Gabazine, 25 μM) the resting membrane potential depolarized and excitability of HU neurons were comparable to neurons from control rats. The results indicate that HU increases TS‐EPSC amplitude via a NMDA receptor component. Furthermore, the decreased excitability and hyperpolarized membrane is associated with enhanced GABAergic modulation to these neurons. This functional neuroplasticity in the nTS may contribute to the cardiovascular deconditioning induced by HU.Support or Funding InformationHL132836 AAS lundbeck fellowship
Experience‐based Modified Sheet Plastination Protocol
Authors: Espinosa-Montagut Nathally , Clavijo-Ordoñez Laura Daniela , Rueda-Esteban Roberto Javier 
Published: April 2020

Specimen preservation has been perfected over time through the application of multiple preservation techniques such as sheet plastination. Already described advantages of this technique are: reduction of risks associated with manipulation, longer shelf life and visualization of both internal and external anatomical structures through the sheets.This method represents an alternative to create models that can be used to teach Gross Anatomy especially because the final cuts obtained from this technique are similar to those seen in diagnostic images such as Magnetic Resonance Imaging or Computed Tomography.Our objective is to present a modified standardized sheet plastination protocol based on experience gained through the technique development in our laboratory and other previously released protocols.As a basis, published protocols such as: BIODUR; University of Murcia, Spain; Dalian University, China; National University, Colombia; among others were used.Since dehydration was the step with the greatest variation, three alternatives were tested: isopropyl alcohol, acetone and ethanol. Forced impregnation is done using BIODUR P‐40 resin until −15mmHg are acquired in the impregnation chamber and cayalysis is then pursued through vertical positioning of the sheets in a Near UV spectrum (NUV) light chamber.Using acetone or ethanol in addition to a longer dehydration time, requires augmented costs and reactant usage, algo, tissue sheets do not set in the center of the vertical chamber, which resulted in broken or bent sheets. Due to this, isopropyl alcohol was chosen as the best intermediate medium. Dehydration changes were made every three days with the solvent at −20°C, starting with a concentration of 95% and making the last refill at 99.8%. The, specimens were placed in a vacuum chamber with BIODUR P‐40 resin. Constant bubbling was monitored while the pressure decreased until bubbling stopped and pressure was further reduced to a minimum of 15 mmHg.Specimens were then assembled on double‐glass sheets with the help of hooks and silicone hoses in vertical shape allowing proper catalysis on both sides simultaneously. This method provided more uniform results and reduced time spent at this stage. Finally, these were placed in a NUV chamber for 72 hours. Near UV‐light was used instead of UV‐light because of the health risk of using UV light chamber in a student access‐free laboratory.In our experience, better results were obtained by making thin cuts of specimens (<6mm) since it facilitates the visualization of structures and allows the resin to remain fully translucent after being catalyzed.Likewise, results improved when using isopropyl alcohol as a dehydration method because it is less volatile allowing a gradual dehydration to limit dimensional change and shrinkage of the tissue.Support or Funding InformationAnatomy Laboratory, School of Medicine, Universidad de los Andes.
Potential lung cancer therapy using plant derived cholesterol structural analogs
Authors: Pérez Caraballo Daraishka M. , Torres Anamaris , Milian Melissa , Delgado Yamixa 
Published: April 2020

The acquired multidrug resistance syndrome (MDRS) is one of the leading causes for the failure of chemotherapy in lung cancer. Recently plant‐derived triterpenoids (eg, cholesterol‐structural analogs) have showed a wide spectrum of pharmacological activities. In addition, in different studies, anticancer agents have been combined to cholesterol moieties to improve their cellular uptake and target specificity. Herein, we investigated the cytotoxic activity of various triterpenoids cholesterol analogs: oleanolic acid (OleA), ursolic acid (UrA), betulinic acid (BeA), asiatic acid (AsA), lupeol (Lupe), stigmasterol (Stg) and β‐sitosterol (β‐Sito) on non‐small lung adenocarcinoma cells (A549) and normal lung cells (MRC5). From our studies, the IC 50 for most of these cholesterol‐analogs were in the low μM range after 24h of incubation. β‐Sito and Stg did not show any significant cytotoxic pattern in this μM range. In addition BeA and OleA showed the highest therapeutic indexes comparing the cytotoxic effect in A549 vs MRC5 cells. Metabolic activity assays were performed to determine the mechanism of action of these natural compounds. Caspases activity and cell membrane integrity assays were performed and all the cytotoxic triterpenoids induced no activation of caspase‐3, and high membrane permeabilization. Gene expression assays of MDRS‐related genes (EGF, VEGF, Pgp, Bcl‐2, P 53 , NDRG1, GLIPR1) demonstrated the downregulation of some of these genes after the incubation with these triterpenoids. These results demonstrated that even slight structural changes in these cholesterol analogs can influence the cytotoxic response and cellular mechanistic pathways. Complete results will be presented. This study opens promising perspectives for further research on the role of phytochemical triterpenoids, which ultimately will contribute to a more rational application in cancer therapy.Support or Funding InformationSJB‐Research Center Seed
Hepcidin inhibits ferroportin in the Xenopus oocyte expression system via a calcium‐dependent mechanism that does not involve endocytosis
Authors: Ruwe T. Alex , Qiao Bo , Bonamer John P. , Azucenas Corbin R. , Ganz Tomas , Nemeth Elizabeta , Mackenzie Bryan 
Published: April 2020

The cellular iron‐exporter ferroportin (Fpn), under the control of the hormone hepcidin, serves as a key control point in iron homeostasis. The canonical mechanism by which hepcidin suppresses Fpn activity comprises hepcidin binding by Fpn and the subsequent internalization and ubiquitin‐dependent degradation of the transporter. Here we explored hepcidin inhibition of 55Fe efflux from RNA‐injected Xenopus oocytes expressing human Fpn. Hepcidin pretreatment induced a rapid inhibition (t½ = 8.2 ± [SEM] 0.5 min; r2 > 0.99, P < 0.001) of Fpn‐mediated 55Fe efflux. Hepcidin had no effect on Fpn activity when we removed calcium from the pretreatment medium (0 Ca2+, 0.1 mM EGTA). The action of hepcidin was not dependent on endocytosis, a conclusion based on the following observations: (i) Inhibition of Fpn by hepcidin was only modestly temperature‐dependent (Q10= 2.5 ± SEM 1.4 over the range 17–27 °C) whereas endocytosis is expected to be strongly temperature‐dependent, Q10 in the order of 5–17 [Weigel PH and Oka JA (1981) J Biol Chem256, 2615–17]. (ii) Inhibition of Fpn by hepcidin proceeded even in the presence of blockers of clathrin‐mediated (chlorpromazine, Dynasore) and clathrin‐independent (filipin, genistein) endocytosis. (iii) Hepcidin treatment inhibited 55Fe efflux in oocytes expressing the (K→R)8‐Fpn mutant, in which 8 Lys residues required for ubiquitination and endocytosis of Fpn were mutated to Arg, as much as in wildtype Fpn. (iv) Confocal LSM imaging of wildtype Fpn‐GFP and (K→R)8‐Fpn‐GFP expression in oocytes revealed no detectable endocytosis of either protein after treatment with hepcidin. (v) Hepcidin treatment produced no meaningful change in membrane surface area (as determined by capacitance) of oocytes expressing Fpn, despite reducing Fpn‐mediated iron transport by 65%. Our data reveal that hepcidin can directly block Fpn activity via a Ca2+‐dependent mechanism that does not involve endocytosis. We speculate that the Xenopus oocyte lacks the specific signal by which hepcidin triggers Fpn internalization. The Xenopus oocyte is therefore an ideal model system in which to study the mechanism by which hepcidin directly blocks Fpn activity.Support or Funding InformationNIH grants R01 DK107309, P30 DK078392, and R25 HL115473, and the American Physiological Society
SPARC: Determining the Projections and Expression Profiles of Neurons of the Stomach‐Brain Axis in Rat
Authors: Furness John B. , Hunne Billie B. , Di Natale Madeleine B. , Molero Juan C. , Stebbing Martin C. 
Published: April 2020

Effectors in the stomach receive motor innervation from intrinsic (enteric) neurons, nuclei in the brain stem, the spinal cord and other gut regions. Sensory signals are conducted to the brain, spinal cord and sympathetic ganglia. We are analyzing the circuits by selective pathway lesions, orthograde and retrograde tracing, RNAScope and immunohistochemistry. Regions of stomach were denervated by myectomy (removing a region of myenteric ganglia), bilateral vagotomy or sympathectomy, or combined surgeries. Retrogradely transported fluorescent microbeads were injected selectively into the gastric mucosa or muscle layers. Neuronal markers were localized by multi‐labeling immunohistochemistry. When a region of longitudinal muscle and myenteric ganglia was removed, and 7–10 days allowed for fiber degeneration, nerve fibers in the circular muscle and muscularis mucosae were no longer detected. Two major nerve fiber types innervated the muscle, fibers immunoreactive for neuronal NOS and VIP that are deduced to be inhibitory motor neurons and fibers that were labelled by tachykinins and cholinergic markers that are deduced to be excitatory motor neurons. Some inhibitory fibers were also immunoreactive for gastrin releasing peptide (GRP). The muscle was also innervated by sympathetic (tyrosine hydroxylase positive) nerve fibers. The mucosa received a mixed motor and sensory supply from myenteric ganglia, submucosal ganglia, the vagus, and sympathetic pathways. Denervation studies showed that VIP fibers arose from both myenteric ganglia and the nodose ganglia; thus VIP is in subpopulations of motor and of sensory fibers. Some VIP fibers ended in close relation to ghrelin‐containing enteroendocrine cells. There were few sympathetic endings in the mucosa and CGRP fibers were also rare. Arteries in the gastric wall were triply innervated by sympathetic noradrenaline/ NPY fibers, tachykinin fibers and VIP fibers. The origins of the perivascular VIP fibers have yet to be determined. Injection of retrograde tracer into the gastric mucosa labeled large populations of nodose ganglion neurons. Some nodose ganglion neurons were labeled both from the gastric mucosa and from the external muscle. The chemical phenotypes of myenteric and submucosal ganglia are being investigated. VIP‐immunoreactive cell bodies were numerous in submucosal ganglia. We conclude that there is a complex interplay between nerve endings originating in myenteric, submucosal, nodose, sympathetic and spinal ganglia in gastric effector tissues.Support or Funding InformationNIH/SPARC
Cinaciguat Reduces Prolyl Hydroxylase 2 (PHD2) Protein Expression in Chronically Hypoxic and Pulmonary Hypertensive Newborn Lambs
Authors: Beñaldo Felipe Augusto , Araya-Quijada Claudio , Serón-Ferre María , Herrera Emilio , Ebensperger Germán , Reyes Roberto , Llanos Aníbal 
Published: April 2020

Newborn lambs at high altitudes (3,600 m) develop pulmonary hypertension due to a sustained hypoxic vasoconstriction followed by a pathological remodeling of small pulmonary arteries (SPA). The latter is produced by several agents, including the transcription factor Hypoxia Inducible Factor‐1α (HIF‐1α). HIF‐1α increases the pulmonary vascular remodeling in chronic hypoxia and the enzyme PHD‐2 is a key factor participating in the degradation of HIF‐1α. Cinaciguat an activator of sGC is able to decrease HIF‐1α, in adults, and increase HO‐1 in neonatal lambs. This enzyme reduces reactive oxygen species (ROS) and cytokines, whereas no information in PHD‐2 and cinaciguat is available. Therefore, we use two groups of 6 newborn lambs each, that were catheterized under general anesthesia and a Swan Ganz catheter was placed into the pulmonary artery, to measure pulmonary arterial pressure (mPAP), cardiac output (CO) and calculate pulmonary vascular resistance (PVR). The groups received, either the activator of sGC (cinaciguat 35 μg kg−1) or vehicle (DMSO : NaCl 0,9%, 1:10), for seven days. Additionally, we took lung samples to perform histology (muscle & adventitia layers in small pulmonary arteries, SPA) and western blots (HIF‐1α and PHD‐2). Forty‐eight hour after the end of treatment, euthanasia was accomplished. All procedures were approved by the local Bioethical Committee (CBA#0643 FMUCH). Cinaciguat did not change the mPAP but did vary the PVR. Mean PAP was not modified because CO increased. Concordant with the lower PVR there was a reduction of the muscular and adventitia layers in SPA. Further, cinaciguat did not modify the HIF‐1α protein expression but showed a decrease in PHD‐2 in pulmonary hypertensive newborn lambs. If ROS and cytokines are diminished (unmeasured) by cinaciguat, both factors could generate a reduction in HIF‐1α, that could lessen PHD‐2 (feedforward). The latter should produce a decrease in HIF‐1α hydroxylation and therefore a reduced destruction in the proteasome, which would lead to an increase in HIF‐1α availability, and eventually to its initial state (feedback). HIF‐1α did not decrease because has a short half‐life in contrast with PHD‐2 that has a half‐life over 48h. In conclusion, the decrease in PHD‐2 could be the consequence of an initial HIF‐1α reduction, producing a diminution in muscle and adventitia layers in small pulmonary arteries consistent with a lesser PVR. The reduction of HIF‐1α could be considered a useful tool to treat the pulmonary hypertension of the neonate.Support or Funding InformationConicyt 21191677, Fondecyt 1140647, Chile.
The Effect of Creatine Monohydrate Supplementation on Tissue Creatine Concentrations in Male and Female Rats
Authors: Dunham Tyler , Murphy Jensen , Colonna Kaitlyn , Fajardo Val , MacPherson Rebecca , Ward Wendy , Roy Brian 
Published: April 2020

BackgroundCreatine is an essential compound that can store chemical energy and act as an energy buffer during times of metabolic stress in mammals. Creatine can be synthesized endogenously, however dietary supplementation with creatine monohydrate (CM) is a common medical intervention and is used as a common ergogenic aid in athletes. The aim of this study was to investigate the effect of increasing doses of dietary creatine on creatine uptake in brain, heart, skeletal muscle, and liver tissues in male and female rats in preparation for future dietary interventions.Methods16 male (536g—670g) and 16 female (339g—487g) 12 week old Sprague‐Dawley rats were given access to drinking water with 0 g/L, 2.5 g/L, 5 g/L, or 10 g/L CM and 1% sucrose for 8 weeks. Free creatine and phosphocreatine tissue concentrations were measured using fluorometric assays and combined to report total creatine compound (TCr) concentrations in brain (BR), heart (HRT), liver (LIV), and skeletal muscle [soleus (SOL), extensor digitorum longus (EDL), and gastrocnemius (GAS)] tissues after the 8‐week dietary intervention.ResultsMales were significantly heavier than females (p<0.001) but there were no differences in body weight between groups of either sex. TCr concentrations in BR were higher with 2.5 g/L (p<0.01), 5 g/L (p<0.05), and 10 g/L (p<0.001) CM compared to control, with only the 2.5 g/L CM dose resulting in a higher TCr concentration in females (p<0.05) compared to males. TCr concentrations in SOL were higher with 5 g/L (p< 0.01) and 10 g/L (p<0.001) CM compared to controls. In EDL and GAS TCr concentrations were higher compared to controls with 2.5 g/L (p<0.01, p<0.05), 5 g/L (p<0.001, p<0.05), and 10 g/L (p<0.001, p<0.01) CM. TCr in GAS showed a trend with females (p<0.10) being higher than males. TCr concentrations in HRT of females were higher with 10 g/L (p<0.01) CM compared to controls and trending towards significance with 5 g/L (p<0.10) CM as compared to controls. TCr concentrations in HRT with 10 g/L CM were significantly higher in females (p<0.001) compared to males. No differences in TCr were observed between groups in LIV.ConclusionsCM supplementation provided in water with 1% sucrose for 8 weeks leads to an increase in TCr in brain, heart, and skeletal muscle, but not in liver. Females appeared to be more responsive to CM supplementation in HRT, especially at the highest dose suggesting that dietary interventions involving CM may affect males and females differently.Support or Funding InformationSupported by NSERC, Canada.