bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining the Optimal Soft Tissue Preservation Techniques for Surgical Skills Training
Authors: Le Elaine , Wang Austine , Rockarts Jasmine , Palombella Andrew , Wainman Bruce , de Sa Darren , Nguyen Laura , Downer Naomi 
Published: May 2022

IntroductionCompetency Based Medical Education, overseen and implemented by the Royal College of Physicians and Surgeons of Canada, requires realistic simulation of specific tasks called Entrustable Professional Activities (EPAs). Mastery of these tasks is required to proceed in the surgical specialty. Due to the growing need for high fidelity training in postgraduate surgical education, there has been a shift from the use of hard‐fixed to soft‐fixed material for improved realism. Currently, there exists no standardized way of assessing the suitability of various fixation techniques for different EPAs.ObjectiveThe current study seeks to establish the most appropriate tissue fixation method for each EPA. Additionally, we aim to develop a standardized matrix to rate the effectiveness of soft‐fixation methods for the purposes of surgical training based on a number of factors such as the EPA, storage, longevity, biohazardous risk, cost, biomechanical properties, and realism.HypothesisWe hypothesize that different soft‐fixation methods possess varying suitabilities for each EPA, which could be deduced through the use of a testing matrix.MethodsEPAs will be performed on cadaveric tissues embalmed with various soft‐fixation solutions. In order to establish the solutions that will be used, initial tests will be conducted on porcine material. Each pork hock (the joint between the tibia/fibula and the metatarsals) will be embalmed with one of 8 soft‐fixation solutions. Surgical residents will perform an EPA on each embalmed tissue and record their observations. The residents will respond to statements about each of the embalming solutions using a 5‐point Likert scale. The results from this testing will be used to select the embalming solutions to be used when the study is conducted on human donors.ResultsTesting of porcine material to determine the most useful fixation technique is expected to be completed in February of 2022. Testing on cadaveric tissue is expected to be completed in July of 2022.ConclusionGaining an understanding of the suitability of various soft‐fixation methods allows for high fidelity surgical skills training and the maximization of the use of each donor.
Estradiol Augments Sensory Nerve‐Mediated Vasodilation in Young Women
Authors: Schwab Allyson I. , Del Vecchio Angelica R. , Welti Laura M. , Haigh Katherine , Feinberg Ronald F. , McGinty Shane J. , Wong Brett J. , Wenner Megan M. 
Published: May 2022

Local heating of the skin elicits biphasic vasodilation: a sensory nerve‐mediated initial peak (axon reflex) and an endothelial‐dependent plateau. We have previously shown that sex hormones, particularly estradiol (E2), improves cutaneous endothelial‐dependent vasodilation, but less is known about the effects of E2 on cutaneous sensory nerve‐mediated vasodilation.PURPOSEWe tested the hypothesis that E2 enhances sensory‐nerve mediated vasodilation in response to local heating of the skin in young women.METHODSWe retrospectively analyzed data in 15 healthy young women (age 24 ± 4 yr; MAP 84 ± 6 mmHg; BMI 24 ± 3 kg/m2). Endogenous sex hormone production was suppressed with daily administration of a gonadotropin‐releasing hormone antagonist (GnRHant; Ganirelix) for 10 days. E2 (0.1 mg/day, Vivelle‐Dot) was added back via transdermal patch on days 4–10. Cutaneous vasodilatory responses to local heating were measured on days 4 and 10 using laser Doppler flowmetry during microdialysis perfusions of lactated Ringer’s (control), and in a subset of women (n=6), L‐NAME (non‐selective nitric oxide synthase inhibition). Cutaneous vascular conductance (CVC) was calculated during the initial peak of the axon reflex during local heating (42°C) and normalized to maximal vasodilation achieved by perfusion of sodium nitroprusside (28mM) and heating to 43°C.RESULTSSensory nerve‐mediated vasodilation increased during E2 administration compared to GnRHant (E2: 71 ± 15, GnRHant: 57 ± 18 %CVCmax; p=0.046). Blockade of nitric oxide with L‐NAME did not blunt the axon reflex during GnRHant (control: 57 ± 18 vs. L‐NAME: 50 ± 17 %CVCmax; p=0.401) or E2 administration (control: 71 ± 15 vs. L‐NAME: 52 ± 19 %CVCmax; p=0.152).CONCLUSIONThese preliminary findings suggest that E2 enhances sensory nerve‐mediated vasodilation in young women, and that this may occur through mechanisms independent of nitric oxide. Future mechanistic studies isolating the nitric oxide component and other pathways could help elucidate the role of E2 in sensory nerve‐mediated vasodilation.
Serum from rats subjected to traumatic brain injury and hemorrhagic shock induces profound endothelial barrier dysfunction
Authors: Ke Yunbo , Proctor Julie , Zhang Chenou , Medina Juliana , Miller Catriona , Junhyun Kim , Grisom Thomas , Birukova Anna , Fiskum Gary , Birukov Konstantin 
Published: May 2022

IntroductionTraumatic brain injury (TBI) has been associated with development of indirect acute respiratory distress syndrome (ARDS). However, the causative relationship between TBI and lung injury remains unclear. To explore potential mechanism linking TBI with development of ARDS, we characterized effects of serum factors released during TBI and hemorrhagic shock (HS) in a rat model on the pulmonary endothelial cell (EC) barrier dysfunction, a key feature of ARDS.MethodsThe adult male rat polytrauma model consisted of controlled cortical impact (CCI)–induced TBI followed by 30 minutes of hemorrhage shock (HS) induced by blood withdrawal. The HS phase was followed by a 1‐hour “prehospital” Hextend fluid resuscitation phase and then a 1‐hour “hospital phase” when shed blood was reinfused. 48 hours after the TBI, blood was drawn from right ventricle and serum samples were obtained. Serum was collected from the TBI or sham rats, and its effects on barrier properties of pulmonary endothelial cell culture were assessed by measurements of transendothelial electrical resistance (TER) using the electrical cell impedance sensor and visualization of fluorescent tracer penetration through EC monolayer using XPerT assay.ResultsWe found pronounced barrier‐disruptive effects of serum samples from animals exposed to controlled cortical impact (CCI) and HS, but not from sham operated rats. Rapid and sustained decrease in EC monolayer transendothelial resistance was observed within minutes after serum addition and remained below basal TER levels after incubation with CCI‐HS sera. Thrombin has been implicated in the early‐phase barrier disruptive activity of CCI‐HS serum, as both thrombin inhibitor and thrombin receptor antagonist attenuated the acute phase of serum‐induced TER decline, but did not affect TER decline at later time points. These findings suggest that thrombin elevation may play a role in early‐phase barrier disruptive activity of CCI‐HS serum. However, both the early and late phases of CCI‐HS‐induced EC permeability were inhibited by heparin. The late phase barrier disruptive effect of CCI‐HS was also prevented by serum preincubation with heparin‐sepharose. Pulmonary EC treated with serum from CCI‐HS rats for 3 hours have demonstrated significant decline in expression of EC junctional protein, VE‐Cadherin, and disassembly of peripheral EC adherens junction complexes monitored by immunostaining with VE‐cadherin antibody.ConclusionThese results suggest that exposure to CCI‐HS leads to production of humoral factors causing early and late‐phase barrier disruptive effects in lung vascular endothelium. While thrombin‐PAR1 signaling has been identified as mechanism of acute EC permeability increase by CCI‐HS serum, the factor(s) defining long‐term EC barrier disruption in CCI‐HS model remain to be determined.
Calcium‐Dependent Dual Oxidase 2 is a Novel Source of Reactive Oxygen Species Implicated in Glomerular Mesangial Cell Fibrotic Response to Angiotensin II and Glucose
Authors: Hecker Jacqueline , Ford Bridget M. 
Published: May 2022

The vasoactive peptide angiotensin II (Ang II) and hyperglycemia contribute to the initiation and the progression of glomerular fibrosis via activation of glomerular mesangial cells (MCs) and subsequent extracellular matrix expansion. We have previously shown that oxidative stress is critical for MC fibrotic response to Ang II or high concentrations of glucose (HG). Here, we demonstrate that Dual oxidase 2 (Duox2), a member of the Nox/Duox family of NADPH oxidases, is present in MCs and that its protein expression, along with its associated maturation factor, DuoxA2, are upregulated by Ang II and HG.Small interfering RNA (siRNA)‐mediated downregulation of Duox2 significantly reduces Ang II‐induced increase in reactive oxygen (ROS) generation and prevents the stimulatory effect of Ang II on MC fibrotic injury (as assessed by measuring a‐smooth muscle actin and fibronectin expression).To demonstrate that Duox2 activation is Ca2+‐dependent, we show that the extracellular Ca2+ chelator BAPTA prevented Ang II‐induced ROS generation and the stimulation of MC fibrotic injury by Ang II. Moreover, treatment of MCs with ionomycin resulted in increased ROS production and enhanced MC fibrotic injury. These effects were abrogated by siRNA targeting Duox2. Fura‐2 fluorescence was utilized as well to show calcium mobilization in response to Ang II and this effect was abrogated with siDuox2 transfection. These data indicate that Ang II‐stimulated Duox2 activation and ROS generation subsequently lead to MC fibrotic injury.In summary, we have identified a novel role for Duox2 and its cognate maturation factor, DuoxA2, as a major source of ROS in response to Ang II and HG and established the significance of Duox2 in Ang II‐mediated MC activation and fibrotic injury. Therapeutic targeting of this pathway may prevent or reverse pathophysiologic manifestations of renal fibrotic diseases.
Ex vivo and In vivo Assays for Drug Discovery and Detection of Photoreceptor Survival Factors
Authors: Bernardo‐Colon Alexandra , Rebustini Ivan T. , Becerra S. Patricia 
Published: May 2022

Retinitis pigmentosa (RP) is one of the most common inherited diseases of the retina (retinopathies) that is estimated to affect 1 in 4,000 people in the United States and worldwide. This collection of genetic diseases leads to progressive photoreceptor cell degeneration and ultimately vision loss, with more than 60 genes implicated in molecular pathways towards photoreceptor cell death. Currently, there are no treatments available and, due to its vast diverse genetic background, a putative gene‐based therapy is challenging. Consequently, mutation‐independent strategies to protect photoreceptors against continued damage and progressive vision loss are appealing approaches. One of them is the use of survival, neurotrophic and neuroprotective factors that target common signaling pathways of cell death in the different types of RP. The aim of this study is to optimize methods to evaluate the efficacy of compounds to protect photoreceptor cells against death.We used PSVue® to optimize the cell death read‐out in cultured retinal explants and in retinas of a mouse model for a human inherited autosomal recessive RP, the rd10 mouse. Retinal degeneration in the rd10 mice is caused by a spontaneous mutation in the gene for the β‐subunit of phosphodiesterase. PSVue® is a robust probe for detecting phosphatidyl serine on the surface of cells undergoing death. We used retinal tissue explanted from wild type mouse eyes, and cultured it ex vivo. Induction of photoreceptor cell death was achieved with Zaprinast, an inhibitor of phosphodiesterase, to mimic the rd10 photoreceptor cell death. Low probe concentrations and short incubation times resulted in a reproducible detection of photoreceptor death in the retina by confocal super resolution microscopy. The PSVue® detection method yielded lower fluorescence background than the TUNEL detection method. Pigment epithelium‐derived factor (PEDF), a photoreceptor survival protein, was used as control to prevent photoreceptor cell death induced by Zaprinast. PEDF supplementation prior to Zaprinast treatment decreased cell death detection, as expected. We used the mouse model rd10 to evaluate photoreceptor death in vivo. PSVue® eye‐drops were administered to the left eye of rd10 mice of P17‐P25 postnatal ages, and fluorescence was detected by fundoscopy using MICRON III a day later. HBBS eye‐drops were administered to the right eye as a control reference. The fluorescence of the probe detected in the back of mouse eyes increased between ages P17 and P23 relative to that of HBBS‐treated eyes. The results revealed a peak of photoreceptor cell degeneration that occurred at P25 days of age in living rd10 mouse models.We have optimized methods to determine photoreceptor cell death in the ex vivo and in vivo experimental systems described here using a fluorescent probe. The methodologies are simple, fast, and complementary, and together they will prove to be suitable for screening factors and drugs against RP.
Cardiac Adjustments During a Hot and Humid Heatwave Simulation in Older Adults
Authors: Foster Josh , Belval Luke N. , Watso Joseph C. , Cimino Frank A. , Orth Bonnie D. , Sarma Satyam , MacNamara James P. , Crandall Craig G. 
Published: May 2022

Heatwaves cause disproportionately high morbidity and mortality rates in those aged ≥ 65 years. While the underlying pathologies are typically of cardiovascular origin, the cardiac specific responses to real‐world heatwave conditions are not well‐defined.PurposeWe tested the hypothesis that three hours exposure to a hot and humid heat wave would increase left ventricular systolic contractility (s’) and early propagation velocity of mitral inflow (Vp) and decrease isovolumetric relaxation time (IVRT).MethodsEight healthy older adults (5 female/3 male; 70 ± 4 years; 26 ± 3 kg·m‐2) were exposed to 41°C, 40% humidity (replicating the 1995 Chicago heat wave) for three‐hours, interspersed with seven 5‐minute work bouts at three METS to replicate daily living activities. Core temperature (telemetric pill or rectal thermistor), skin temperature, blood pressure and heart rate were monitored continuously during heating. Water was provided throughout the protocol to minimize dehydration. Echocardiograms were taken at baseline (in a thermoneutral environment) and at three hours into heat stress to assess cardiac function. Pre to post heatwave differences in all variables were compared using paired samples t‐tests.ResultsCore temperature increased (36.7 ± 0.3 to 37.7 ± 0.5°C, p < 0.001), skin temperature increased (34.0 ± 1.1 to 36.2 ± 0.8°C, p = 0.002), heart rate increased (59 ± 9 to 78 ± 18 b·min‐1,p = 0.012), and mean arterial pressure decreased (90 ± 14 to 78 ± 12 mmHg, p= 0.034) from baseline to 3‐hours heat exposure. Left ventricular contractility (s’) increased (8.2 ± 1.0 to 10.4 ± 1.4 cm/s, p = 0.002), while measures of diastolic function were unchanged during heating (p > 0.14 for Vp, IVRT, E, A, E/A, e’, E/e’).ConclusionsOur preliminary findings suggest that humid heatwave exposure increases left ventricular contractility without impacting diastolic function in healthy older adults.
Identification of microRNA Targets in colorectal cancer through Data Sequencing
Authors: Rubio‐Guevara Susana , Olascuaga‐Castillo Karyn , Cáceres‐Andonaire Elena , Altamirano‐Sarmiento Dan , Caballero‐Aquiño Olga , Mantilla‐Rodríguez Elena , Hilario‐Vargas Julio , Berezovski Maxim , Morgado‐Díaz José Andrés 
Published: May 2022

Colorectal cancer (CRC) is the third leading cause of cancer‐related mortality globally. MicroRNAs (miRNAs, miRs), a class of small non‐coding RNA molecules, have demonstrated important roles in carcinogenesis and its progression through the regulation of the epithelialmesenchymal transition (EMT), oncogenic signaling pathways, and metastasis. Despite the increase in miRNA studies and extensive analyzes of their expression, the role and function of many individual miRNAs in CRC remains poorly understood. The aim of this study was to identify miRNA targets in CRC through data sequencing, which could be a solid prognostic prediction tool and help clinical strategy.MethodsCRC gene expression data sets were collected from the public database, The Cancer Genome Atlas (TCGA). In addition, web‐based tools were used to explore TCGA data, specifically the one developed by the Broad Institute TCGA GDAC Firehose, which provides data sets, algorithms, and analysis results standardized for TCGA. This pipeline has the following steps: The CLR (Context Likelihood of Relatedness) approach is applied to infer putative miRNA regulatory connections: gene; miRNA filtering: gene pairs based on Pearson's correlation (<= ‐0.3); and miRNA filtering: gene pairs based on predicted interactions in three sequence prediction databases (Miranda, Pictar, Targetscan). The CLR algorithm was applied on 617 miRs and 18012 mRNAs across 220 samples. After 2 filtering steps, the number of 9 miR:genes pairs were detected.ResultsThe initial search with the term “Colorectal adenocarcinoma”, “COADREAD” yielded 631 cases. After the analysis of these samples, data on the significance miR:gene pairs were obtained and Table 1 shows the results of miR:gene pairs with corr < ‐0.30 and predicted interactions in three sequence prediction databases. About the miRNA connections, Table 2 shows all miRNA hubs with their associated genes in the putative direct target network. Finally, about gene connections, Table 3 shows all gene hubs with their associated miRNAs in the putative direct target network.ConclusionThe use of miRNAs as biomarkers for CRC could provide a new and less invasive technique to detect CRC and help determine prognosis. These miRNAs and their targets require further evaluation for a better understanding of their associations, ultimately, with the potential to develop new therapeutic targets. Therefore, it is proposed to develop a screening panel that should consist of multiple miRNAs that would provide a more accurate and efficient screening tool for CRC.
Effect of a C‐terminal Electrostatic Interaction Domain on KCC3 Function
Authors: Flores‐Carrillo Alejandrina , Mercado‐Rodríguez Diana , Mercado Adriana , de los Heros Paola 
Published: May 2022

BackgroundThe K:Cl cotransporters (KCCs) are key players to maintain cellular volume, mediate epithelial transport and intracellular chloride concentration, and regulate GABA neurotransmission. Under isotonic conditions, KCCs are normally inhibited due to the phosphorylation of residues located within the cytoplasmic domains. On the contrary, dephosphorylation of those residues in response to hypotonic cell swelling stimulates transport activity. Dysfunction of these proteins and the processes involved in their regulation have been associated with various human diseases by alteration of ionic homeostasis mainly in the kidney and the brain. Based on the cryo‐EM structures recently reported of human KCCs, revealing structural determinants for regulation in both N‐ and C‐terminal domains, in the present study we analyzed the effect of a structural domain located at the C‐ terminal involved in electrostatic interactions. It has been stated that the side chains of residues as Gln (Q), Arg (R) and Lys (K) tend to form hydrogen bonds promoting the stabilization of tertiary and quaternary protein structures. However, whether the phosphorylation status is modified after the electrostatic disruption is unknown.MethodsXenopus laevis oocytes and HEK 293 cells were either microinjected or transfected with KCC3a wild type (WT) or C‐terminal mutants, Q905A, Q905/K934A (2M), Q905/K934/R937A (3M) and Q905/K934/R937/K938A (4M), key residues involved in electrostatic interactions and located within the C‐terminal domain of the cotransporter. The phosphorylation status of KCC3a in response to isotonic and hypotonic conditions was evaluated by immunoblot analysis of three key regulatory phosphorylation sites (pSer96, pThr991 and pThr1048). In parallel, phosphorylation status of SPAK/OSR1 activating regulatory site pSer373/pSer325 was analyzed under the same conditions.ResultsCell swelling‐induced dephosphorylation is not observed on C‐terminal electrostatic interaction domain mutants compared to WT KCC3 in X. laevis oocytes and HEK cells. All three regulatory‐phosphorylation sites in KCC3a mutants remained phosphorylated under hypotonic conditions where dephosphorylation is required for the protein to become active. These results suggest that the disruption of the hydrogen bonds could disrupt the proper folding of the protein and thus interfere with the regulatory dephosphorylation/phosphorylation signaling pathway which is known to activate the transporter after cell swelling.ConclusionsOur results show that the four residues in the electrostatic interaction domain of the C‐termini are involved in KCC3a response to hypotonic conditions affecting the phosphorylation status of the cotransporter. The side chains of these residues seem to be important in maintaining tertiary conformation given their ability to form hydrogen bonds and thus, the disruption of their interactions affects the cotransporter ability to respond to osmotic and cell volume changes.
Use Of Weighted Gene Coexpression Network Analysis To Identify Connectivity Between Gut And Brain Gene Expression
Authors: Khan Tasnin , Hatami Asa , Zhu Chunni , Kawaguchi Riki , Joshi Swapna , Chen Han , Hoffman Jill , Law Ivy K. M. , Rankin Carl R. , John Varghese , Geschwind Daniel , Pothoulakis Charalabos , Videlock Elizabeth J. 
Published: May 2022

BackgroundAlterations in the gut brain axis are being recognized as a pathogenic factor for an increasing number of diseases, including neurodegenerative diseases such as Parkinson Disease (PD). The extent to which gene expression profiling in the gut and the brain is co‐regulated is not well understood. Weighted gene coexpression network analysis (WGCNA) uses unbiased hierarchical clustering to reduce gene expression profiling data to modules of highly correlated genes.HypothesisGut‐brain connectivity will be strongest for modules related to physiologic mechanisms with a systemic component, such as immune reactivity.MethodsWGNCA networks were constructed for distal colon and striatum RNA seq data from mice overexpressing human wild type alpha synuclein (ASO, n=18) and wild type (WT, n=16) mice at 1 and 3 months. Mice with matched colon and striatum data (n=10/6 ASO/WT) were included in this analysis. Linear regression identified associations between colon and striatum modules. For this analysis, we controlled for both age and genotype as genotype‐ and age‐associated modules could be correlated due to these covariates alone. Colon‐striatum intermodular connectivity was visualized in Cytoscape. Overrepresented gene ontology (GO) terms in WGCNA modules were determined using the hypergeometric function in the GOstats package in R. Enrichment for gene signatures from single cell sequencing data was determined using the hypergeometric test against cell type signatures from the Panglao and Cellmarker databases.ResultsSelected associations are shown in Figure 1. There are strong correlations between colon and striatum modules that are enriched for terms related to the immune response. Modules most clearly related to the immune response are highlighted in yellow, but several other modules are also closely related to the immune response. For example, there is an association between the striatum module enriched for endothelial cells of the blood brain barrier, and the colon module enriched for goblet cells which produce the mucus layer of the epithelium, a key component of the innate immune system.ConclusionsThrough analysis of matched colon and striatum samples, we can see correlations between gene expression in the colon and striatum. Most modules in this gut‐brain network have some relevance to the immune system which is not unexpected. These results demonstrate the feasibility of “profiling” the gut‐brain axis. A larger sample size would permit evaluation of disease‐related changes in this profile.