bluuebunny/crossref_metadata_2025_split huggingface dataset:
Progressive Collecting Liver Lymphatic Vessels Dysfunction over the Course of Extrahepatic Cholestasis
Authors: Gasheva Olga Yu. , O’Brien April , White Tori K. , Alpini Gianfranco D. , Zawieja David C. , Glaser Shannon , Gashev Anatoliy A. 
Published: April 2020

Liver produces a large fraction of total lymph flow (25–50%). Transport function of lymphatics is altered during inflammation, which impacts the pathogenesis of numerous diseases. Despite their importance in liver function, the functional characteristics of liver lymphatic vessels (LLVs) have been never evaluated in health and disease. We evaluated liver lymphatic vessel (LLV) function in normal and cholestatic rats following extrahepatic bile duct ligation (BDL). LLV contractility/pumping characteristics were determined in LLVs isolated from Sprague‐Dawley rats in control, 1, 3 and 7 days after BDL (BDL1, BDL3, and BDL7) and sham groups. LLV pumping/contractility was analyzed in all groups. Control LLVs had outer diameters of ~500 um, typical lymphatic tone (~7%), moderate contraction amplitude (15–35%), high contraction frequency (12–21 contractions/min) and strong active pumping (5–7.5 vol/min). Over the course of its duration, the BDL significantly altered LLV contractile/pump function, inducing an enlargement of LLVs; their decreased tone; lowering of phasic contractions frequency responses to increases in stretch. Cumulatively, BDL induced progressive decline in minute pumping of LLVs with complete cessation of phasic lymphatic contractions after seven days of BDL. In addition, BDL even after one day completely ablated the light imposed flow‐dependent relaxatory/inhibitory reactions of LLVs observed in control. Progressive dysfunction of LLVs correlates with cholestasis‐induced alterations in liver and bile ducts. We believe that observed BDL‐induced changes in LLVs are likely the result of the liver inflammation and will further promote the inflammatory edema known to occur in the liver during BDL. Thus, LLV dysfunction may play important roles in the ensuing pathogenesis of cholestasis and merit further study.Support or Funding InformationNIH/NIDDK R01 DK110035; NIH/NHLBI 1U01HL123420; funds from TAMU HSC COM and Dept. of Medical Physiology.
Adiponectin rescues the newborn rat lung from lipopolysaccharide (LPS)‐induced inflammation and injury
Authors: Despotovic Nikola , Ivanovski Nikola , Ivanovska Julijana , Belik Jaques , Gauda Estelle B. 
Published: April 2020

IntroductionPreterm infants born during the canalicular and saccular stages of lung development are at high risk for lung injury from oxidative stress and inflammation. Low adipose tissue mass is associated with low serum levels of protective anti‐inflammatory and anti‐oxidative adipokines, such as adiponectin (APN). The modulatory role of APN on inflammatory cytokines and tissue remodeling has unveiled APN as a novel therapeutic target for developmental lung pathologies. We have previously shown that prophylactic administration of exogenous APN protects the newborn rat from LPS‐induced lung injury. In this study, we investigate the ability for systemic APN given 20 hours after LPS aspiration to reverse lung injury in newborn rats.MethodsSprague‐Dawley rats at postnatal day (PND) 4 were treated with 5 mg/kg intrapharyngeal (IPh) LPS or saline; 20 hours later, 2 mg/kg recombinant APN (rAPN) or equal volume saline was administered intraperitoneally (IP). The three treatment groups included: rats exposed to LPS (IPh)/rAPN (IP), LPS (IPh)/saline (IP) and saline (IPh)/saline (IP). Lungs were harvested 6 hours after administration of rAPN and processed for gene (qPCR) and protein (SDS‐PAGE Western blot) expression. In another cohort of PND4 rats, rAPN was administered at 20 and 44 hours, with lungs removed and assayed for histopathology with haemotoxylin and eosin staining 72 hours after LPS. n=4 in each treatment group for gene/protein expression and histopathology.ResultsDifferences were observed in gene and protein expression between treatment groups (ANOVA, p<0.05). In animals treated with IP rAPN 20 hours after IPh LPS, mRNA expression of macrophage inflammatory protein‐1α (MIP‐1α), monocyte chemoattractant protein‐1 (MCP‐1), IL‐1β, IL‐6, and IL‐10 was reduced 7‐, 8‐, 3.6‐, 1.6‐ and 13‐fold, respectively, relative to saline treatment. Protein expression of tumor necrosis factor α (TNF‐α), IL‐1β and IL‐10 was also relatively reduced in rAPN treated rats. No change was detected in the mRNA expression of TNF‐α, or in the protein expression of IL‐6. Lungs treated with rAPN had a marked reduction in histopathological changes relative to saline‐treated controls.ConclusionsOur novel in vivo study demonstrates that beyond the preventative role of systemic APN in neonatal lung injury, APN can also attenuate previously induced acute, inflammatory lung injury. We speculate that increasing serum APN levels in preterm infants might protect from acute and chronic inflammatory lung injury.Support or Funding InformationWomen’s Auxiliary Board at SickKids
Essential Anatomy for Radiology in the Undergraduate Medical Curriculum
Authors: Keim Sarah , Lopez Lisa , McNary Thomas , Zumwalt Ann , Harrell Kelly , Davies David , Cotter Meghan , Martindale Jim , Harmon Derek , Hankin Mark 
Published: April 2020

IntroductionTo prepare medical students for clinical training and practice, it is critical to understand the anatomical knowledge considered most important for different clinical specialties.AimTo address this issue, a consortium of anatomists in the US and Canada is collecting data from clinical educators in Radiology clerkships and electives to identify the anatomy they consider essential.MethodsAn IRB‐approved, online survey (Qualtrics, Seattle, WA) was used to assess the importance of 98 anatomical topics in seven body regions. The study first examined the percentage of Radiology clinical educators (clerkship/elective directors and attending physicians) that considered each anatomical region important to their specialty. Second, the study examined the rank assigned to each anatomical topic using an ordinal scale from 1 (not important) to 4 (essential).ResultsAt the time of abstract submission, data had been collected from 15 Radiology clinical educators at 9 medical schools. The percentage of Radiology clinical educators that considered each anatomical region important to their specialty were (highest‐to‐lowest): Back (100%), Thorax (100%), Abdomen (100%), Pelvis & Perineum (100%), Head & Neck (100%), Upper Limb (93%), and Lower Limb (93%). Further data analysis has identified the highest ranked anatomical topics in each body region for the Radiology clerkship/elective.Discussion and ConclusionThis database provides detailed information regarding the most clinically relevant anatomical topics as identified by Radiology clinical educators. This information can aid in focusing preclinical learning to best prepare medical students for success in their undergraduate and graduate clinical experiences.
Sub‐diaphragmatic vagal nerve stimulation alleviates rodent hypertension associated with gut dysbiosis and reduced serotonergic vagal afferent signaling
Authors: Yang Tao , Ayaz Basak Donertas , Araujo Alan , Dirr Elliott W. , Baekey David M. , Otto Kevin J. , de Lartigue Guillaume , Zubcevic Jasenka 
Published: April 2020

IntroductionThe gut‐brain vagal axis, of which serotonin (5HT) is an important mediator, can be altered by the gut microbiota. Low vagal tone and autonomic imbalance is present in conditions marked by gut dysbiosis including in hypertension (HTN); however, the effect of gut dysbiosis on vagal sensory/afferent function in HTN is unknown. We hypothesized that HTN‐associated gut dysbiosis will decrease serotonergic vagal afferent signaling from the gut and cause autonomic imbalance leading to increased blood pressure (BP). Moreover, we propose that restoring the vagal gut‐brain axis by chronic vagal stimulation will alleviate HTN.MethodsFecal matter transplant (FMT) was performed from either the spontaneously hypertensive (SHR) or Wistar‐Kyoto rats (WKY) to control WKY. BP and autonomic variables were recorded using radiotelemetry. Colonic 5HT, expression of 5HT3a receptors (5HT3aR) along the vagal gut‐brain axis, and cardiovascular responses to systemic 5HT3aR agonist injection were determined in the FMT rats, WKY and SHR. In vivo Ca2+ imaging was performed in gCAMP‐labeled nodose ganglia (NG) neurons in response to 5HT3aR agonist in WKY and SHR. Lastly, SHR were implanted with cuff electrodes on the sub‐diaphragmatic ventral vagal trunk for chronic vagal stimulation (sVNS) while measuring BP and autonomic variables using radiotelemetry. Endpoint bacterial 16s sequencing determined the effects of sVNS on SHR gut dysbiosis.ResultsFMT from SHR but not WKY significantly increased BP (P<0.05 vs baseline) and resulted in autonomic imbalance (P<0.05 vs baseline) in control WKY. This was associated with reduced colonic 5HT levels (P<0.01 vs FMT from WKY), as well as reduced 5HT3aR gene expression in vagal sensory (NG) neurons (p<0.05 vs FMT from WKY) and the brainstem region receiving vagal sensory projections (P<0.01 vs FMT from WKY). Furthermore, NG neuronal firing in response to 5HT3aR agonist corresponded with a time‐locked reduction in the HR in WKY, but both 5HT3aR agonist‐induced NG firing rates and HR responses were significantly blunted in the SHR (P<0.05). In addition, 5HT3aR agonist‐dependent HR responses were also reduced in the WKY following FMT from SHR (P<0.05 vs FMT from WKY). Crucially, chronic sVNS alleviated SHR HTN over eight weeks (P<0.05 vs SHAM SHR), without reversing gut dysbiosis, suggesting that the observed BP effect may primarily be due to restoration of the vagal afferent gut‐brain signaling.ConclusionsHTN‐associated gut dysbiosis reduces serotonergic gut‐brain vagal signaling and increases BP. Restoring vagal afferent tone is effective in alleviating HTN in the SHR.
Is Blue Light the Next Little Blue Pill?: Effects of Light‐Stimulation on Erectile Dynamics
Authors: Favor Justin La , DeYong Matthew , Berkowitz Dan , Bivalacqua Trinity , Burnett Arthur 
Published: April 2020

INTRODUCTIONMany major risk factors for erectile dysfunction (ED) are associated with depressed nitric oxide (NO) availability. Phosphodiesterase type 5 inhibitors are the current first line therapy for ED and are ineffective in 30–50% of patients, largely due to impaired NO production. New therapeutic approaches for ED are needed under such conditions. The phenomenon of light‐stimulated vasodilation has recently been described in aortic tissue, which is enhanced by G‐protein coupled receptor kinase 2 (GRK2) inhibition and particular for blue light. The objective of this project was to determine if this GRK2 sensitive photorelaxation response is active in erectile tissue and the contribution of the NO signaling pathway to the response.METHODSYoung male mice (n = 4–8 / experiment) were sacrificed and erectile tissue was harvested from the shaft of the penis. Ex vivo constriction and relaxation responses were assessed in a muscle strip myograph. The GRK2‐sensitive photorelaxation response was assessed ± 1 μM GRK2 inhibitor using nine different wavelengths (365–700 nm) of light at constant intensity (100 Lux), and then at nine different light intensities (1–1000 Lux) at 455 nm. The contribution of the NO signaling pathway to the GRK2‐sensitive response was tested with stimulations of 20 and 100 Lux at 455 nm with 1 μM GRK2 inhibitor ± the NO synthase inhibitor L‐NAME, the soluble guanylate cyclase (sGC) inhibitor ODQ, the protein kinase G (PKG) inhibitor Rp‐8‐Br‐cGMPS, or the NO scavenger cPTIO, as well as in tissue from mice with a deletion of endothelial + neuronal NO synthase. Differences in responses were determined by two‐way repeated measures ANOVA followed by Sidak’s post hoc test where appropriate.RESULTSMaximal relaxation responses at 455 nm increased with increasing light intensity in the absence (2–10%) and presence (57–103%) of the GRK2 inhibitor, demonstrating a stark increase in photorelaxation under GRK2 inhibition. However, this response waned more rapidly at intensities > 100 Lux. Significant GRK2‐sensitive responses were observed at 365, 395, 430, and 455 nm at 100 Lux intensity, with no significant responses observed in the 490–700 nm range. Both L‐NAME and deletion of endothelial/neuronal NO synthase increased the magnitude of relaxation at all time‐points at 20 Lux, and prolonged maximal relaxation at 100 Lux. CPTIO prolonged the relaxation response at both intensities. ODQ drastically blunted the photorelaxation response at all time points and intensities. Rp‐8‐Br‐cGMPS had no effect on photorelaxation.CONCLUSIONSGRK2‐sensitive photorelaxation was determined to be optimal in the 430–455 nm (violet‐blue) range at ~100 Lux. Depletion of NO by scavenging, enzyme inhibition or genetic deletion enhanced the response, which is sGC‐dependent but PKG‐independent. These findings have implications for treatment of ED due to low NO availability if the GRK2‐sensitive photorelaxation pathway can be harnessed therapeutically.
SPARC: The Structure and Location of Vagal Nociceptive Nerve Fibers in the Mouse Trachea
Authors: Patil Mayur , Kim Seol-Hee , Taylor-Clark Thomas E. , Kollarik Marian 
Published: April 2020

Vagal afferent innervation of the airways and lungs comprises of afferent fibers from vagal nodose neurons (developmentally derived from epibranchial placodes) and vagal jugular neurons (derived from neural crest). Here we evaluated the structure and the location in tracheal wall of afferent nerve fibers innervating the trachea focusing on the nociceptive TRPV1‐positive fibers (putative C‐fibers). We used genetic neuronal tracing in several mutant mice, including two new strains we generated. The wholemount preparations of the trachea were immunostained for fluorescent proteins and imaged by spinning‐disk confocal microscopy. In the TRPV1‐Flp/Tac1‐Cre/RC:FLTG mice (N=3) in which GFP is selectively expressed in cells positive for both TRPV1 and Tac1 (in the vagal system the marker of TRPV1‐positive fibers derived from neural crest) we observed dense innervation of the trachea. In the anterolateral tracheal wall the TRPV1+Tac1+ fibers were located beneath the epithelium in the mucosa above tracheal ligaments (which connect tracheal rings) running transversally (i.e. in parallel with tracheal rings). These fibers ramified richly and repetitively. In the dorsal (membranous) tracheal wall the TRPV1+Tac1+ fibers were also located beneath the epithelium in the mucosa above tracheal smooth muscle, running craniocaudally and often branching. These fibers occasionally penetrated through the tracheal smooth muscle. Some TRPV1+Tac1+ fibers were also observed in the epithelium in the sublaryngeal region of the trachea. In the TRPV1‐Cre mice unilaterally injected with AAV9‐FLEX‐EGFP or AAV9‐FLEX‐tdTomato virus vector into vagal ganglia (N=4), in which only the vagal TRPV1‐positive fibers express GFP or tdTomato, the vagal TRPV1+ fibers had the same pattern as TRPV1+/Tac1+ fibers, but with expected lower density and patchy distribution. Similarly, in the Tac1‐Cre mice unilaterally injected with AAV9‐FLEX‐EGFP vector into vagal ganglia (N=3) in which only the vagal Tac1‐positive fibers express GFP had the same pattern. In contrast, in the TRPV1‐Flp/P2X2‐Cre/RC:FLTG mice (N=3) in which GFP is selectively expressed in cells positive for both TRPV1 and P2X2 (the marker of vagal nociceptors derived from placodes) the TRPV1+/P2X2+ fibers were almost absent in the trachea. However, in the P2X2‐Cre mice unilaterally injected with AAV9‐FLEXEGFP vector into vagal ganglia (N=2) in which GFP is selectively expressed in vagal P2X2− positive fibers, the P2X2+ fibers had distinct distribution from TRPV1+Tac1+ and often located in the tracheal smooth muscle and tracheal epithelium. Our data indicate that vagal afferent nociceptive (TRPV1+) nerve fibers (putative C‐fibers) innervating the mouse trachea originate almost exclusively from jugular ganglion neurons. In contrast, vagal nodose ganglia project only TRPV1‐fibers into the trachea. Our results are in agreement with electrophysiological studies in other species.Support or Funding InformationNIH SPARC
Contribution of Mitochondrial Reactive Oxygen Species to Chronic Hypoxia‐Induced Pulmonary Hypertension
Authors: Yan Simin , Walker Benjimen R. , Jernigan Nikki L. , Resta Thomas C. 
Published: April 2020

Preliminary data from our laboratory support a major role for mitochondria‐derived reactive oxygen species (mitoROS) in mediating elevated basal pulmonary arterial tone following chronic hypoxia (CH) in rats. However, neither the effect of CH on mitoROS production in pulmonary arterial smooth muscle cells (PASMCs), nor the contribution of mitoROS to pulmonary hypertension (pHTN) in this setting are understood. We hypothesized that CH increases PASMC mitoROS production, and that mitoROS contribute to the progression of CH‐induced pHTN. To test these hypotheses, we measured mitoROS production by fluorescence detection of the mitochondrial O2− indicator MitoSOX in primary cultures of PASMCs from control and CH (4 wk, 0.5 atm) rats. Experiments were conducted in the presence of the mitochondria‐targeted antioxidants MitoQ, MitoTEMPO or vehicle. We additionally measured indices of pHTN in rats treated with the mitochondria‐targeted antioxidant MitoQ (500 μM) or vehicle in their drinking water for the entire 4 wk duration of normoxic or hypoxic exposure. Groups were compared statistically by two‐way ANOVA. Values of n indicate numbers of animals. We found that MitoSOX fluorescence was significantly (p < 0.05) greater in PASMCs from CH rats compared to normoxic controls, and this response was prevented by MitoQ and MitoTEMPO (n=6–7). Furthermore, MitoQ attenuated CH‐induced increases in right ventricular (RV) systolic pressure in isoflurane‐anesthetized rats, as well as RV hypertrophy as assessed by Fulton’s index (n=4, p < 0.05). We conclude that CH increases mitoROS production in PASMCs, and that mitoROS provide an important contribution to the development of pHTN following CH.Support or Funding InformationThis work was supported by NIH grant R01 HL132883 (to T.C. Resta).
SREBPs in the control of intestinal homeostasis and tumorigenesis
Authors: Engelking Luke , Xu Yanchao 
Published: April 2020

Lipids are key regulators of the growth and differentiation of intestinal epithelial cells, including intestinal stem cells (ISC). High‐fat diets and obesity are serious risk factors for gastrointestinal cancers in humans. Sterol regulatory element‐binding proteins (SREBPs) are transcription factors that control lipid synthesis and uptake in the intestine. Our recent studies have shown that SREBPs and their major products, sterols (from SREBP‐2) and unsaturated fatty acids (from SREBP‐1) have a critical role in sustaining growth of the intestinal epithelia: (1) The loss of Scap, which controls intracellular cleavage events required for SREBP activation, reduces lipid synthesis and causes a lethal intestinal injury in mice characterized by a loss of intestinal crypts, which house ISCs. (2) When SREBP‐2 is inactivated in intestinal epithelium, hyperplasia of intestinal crypts and hypertrophy of the intestine results. In SREBP‐2 knockouts, sterol synthesis falls while unsaturated fatty acid synthesis does not, owing to an increase in SREBP‐1. (3) Despite this overgrowth phenotype, ablation of SREBP‐2 in intestinal epithelia of mice blocks the formation of adenomas caused by mutant APC. These findings indicate that SREBPs govern intestinal epithelial homeostasis in complex ways. We propose that SREBPs maintain homeostasis of intestinal epithelia by producing specific, yet‐to‐be identified lipid metabolites that sustain the proliferation of ISCs. These pathways control intestinal organ size and malignant potential, which bears on human diseases of under‐ or over‐proliferation of the intestine, such as short gut syndrome and colorectal cancer, the 3rd most common cause of cancer death in the U.S.Support or Funding InformationNIH‐R01DK121842, NIH‐K08DK102652
Characterization of the Tyrosyl‐S and Tyrosyl‐Z tRNA Synthetases from Pseudomonas aeruginosa and Discovery of Inhibitors
Authors: Bullard James M. , Hughes Casey A. , Escamilla Yaritza 
Published: April 2020

IntroductionPseudomonas aeruginosa, a Gram‐negative opportunistic pathogen, is a leading cause of nosocomial infections. The ability of this bacteria to form resilient biofilms on implanted medical devices results in high mortality rates. Patients with cystic fibrosis (CF) are especially at risk as P. aeruginosa colonizes the lungs of these patients forming biofilms which leads to chronic infections and is a leading cause of death. Aminoacyl‐tRNA synthetases (aaRSs) catalyze the covalent attachment of amino acids to their cognate tRNAs. These enzymes are essential for protein synthesis in bacteria and serve as validated targets for the development of new anti‐infectives. Unlike in other bacteria, the P. aeruginosa genome contains two genes (tyrS and tyrZ) which encode two distinct TyrRS enzymes, which are very different at the amino acid level containing only 27% conserved amino acid residues.Methods and ResultsThe kinetic parameters for the interaction of these enzymes with their three substrates (tRNA, ATP, tyrosine) were determined using timed aminoacylation and ATP:PPi exchange assays. The KM for interaction with tRNA, ATP, and tyrosine were 1.5, 204, 172 μM and 2.1, 496, 29 μM for TyrRS‐S and TyrRS‐Z, respectively. The kcat values for interaction with tRNA, ATP, tyrosine were 0.19, 1.0, 3.8 s−1 and 1.9, 3.8, 3.1 s−1 for TyrRS‐S and TyrRS‐Z, respectively. Both forms of TyrRS were developed into screening platforms using scintillation proximity assay (SPA) technology. Using this assay, a synthetic compound library from ChemDiv, Inc. containing over 2000 distinct compounds was screened to detect compounds with the ability to inhibit the function of TyrRS. Four compounds (BCD37H06, BCD38C11, BCD49D09, and BCD54B04) were confirmed as hit compounds. All four compounds inhibited the activity of TyrRS‐S and one of the compounds inhibited TyrRS‐Z. The compounds exhibited IC50 values in the low μM range. These compounds were found to have moderate broad spectrum inhibitory activity (MICs) against a panel of ten pathogenic bacteria. The compounds were all shown to be bacteriostatic in time‐kill kinetic assays. In competition assays, none of the compounds competed with tyrosine for binding, however BCD38C11 and BCE49D09 were competitive with ATP for binding. None of the compounds inhibited growth of human cell cultures.ConclusionTyrRS‐S and TyrRS‐Z from P. aeruginosa were characterized and used for development of screening platforms to identify compounds that have the potential for development as antibacterial agents against drug resistant pathogenic organisms.Support or Funding InformationThe authors are grateful for the financial support provided by the National Institutes of Health (grant number: 1SC3GM098173).