bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sigma‐1 Receptors Promote Lymphatic Endothelial Barrier Function
Authors: Abdelmaboud Salma S. , Motawe Zeinab Y. , Breslin Jerome W. 
Published: April 2020

The lymphatic endothelium plays important roles in lymphatic contractile activity, lymph transport and maintaining a barrier between the lymph and interstitial compartments and its dysfunction is a key factor in the pathogenesis of lymphatic diseases such as lymphedema. Sigma‐1 (σ1) receptors are chaperone proteins located in the endoplasmic reticulum were recently identified to promote collecting lymphatic dilation through endothelial production of nitric oxide. However, the role of σ1 in other functions of lymphatic endothelial cells are not clear. The aim of the current study was to test the hypothesis that σ1 promotes barrier function of lymphatic endothelium. We confirmed expression of σ1 in adult and juvenile human dermal lymphatic endothelial cells (HDLEC) using the ProteinSimple Western (WES) system and immunofluorescence microscopy. To test whether activation of σ1 promotes lymphatic endothelial barrier function, we applied the selective agonist PRE‐084 to cultured monolayers of HDLEC and determined the transendothelial electrical resistance (TER) as an index of barrier function using electrical cell‐substrate impedance sensing. The contribution of basal σ1 activity to HDLEC TER was also assessed either with the σ1 antagonist BD1047 (200 nM) or by silencing σ1 expression with siRNA. Because σ1 has been previously described to be located in the ER‐mitochondrial membrane interface, we also evaluated its role in endothelial bioenergetics using the Agilent Seahorse system glycolytic rate assay. Lastly, we tested the ability of PRE‐084 to counteract IL‐1β‐induced barrier dysfunction in HDLEC monolayers. The results show that the activation of σ1 receptor with PRE‐084 increases HDLEC TER in a concentration‐dependent manner, with 50, 100, 150, and 200 μM PRE‐084 eliciting significant elevations in TER (100 μM was chosen for subsequent experiments). Blockade of σ1 either with the antagonist BD‐1047 or reducing σ1 expression with siRNA resulted in decreased HDLEC TER. PRE‐084 also enhanced basal and compensatory glycolysis as well as proton efflux rate in HDLEC. Moreover, PRE‐084 partially counteracted the IL‐1β‐induced TER drop indicating its potential anti‐inflammatory impact on lymphatic endothelial cells. Collectively our results suggest that σ1 contributes to basal lymphatic endothelial barrier function, potentially through its ability to enhance glycolytic ATP production. Our work also highlights the therapeutic potential of σ1 agonists for preventing lymphatic barrier dysfunction caused by inflammatory mediators.Support or Funding InformationThis work was supported by NIH Grant R01GM120774.
Hypertension Upregulates Cerebral Microarteriolar Expression of p47phox and Contractions to Angiotensin II in Mice
Authors: Wilcox Christopher Stuart , Li Lingli , Lai En Yin , Welch William 
Published: April 2020

BackgroundThe cerebral circulation requires mechanisms to protect it against vasoconstriction since prolonged reductions in cerebral blood flow predispose to stroke or cognitive decline. However, although cerebral microarterioles (CAs) are normally resilient to angiotensin II (Ang II) contractions, prolonged Ang II causes oxidative stress and enhanced contractility in many vascular beds, but direct effects on CAs are not known. In contrast, the renal circulation requires robust responses to adjust renal function to the body’s needs. We reported that contractions of renal afferent arterioles (Affs) are enhanced by superoxide from p47phox/NOX2 or from reduced superoxide dismutase (SOD) expression but diminished by H2O2 from POLDIP2/NOX4. We tested the hypothesis that hypertension itself enhances vasoconstriction of CAs via p47phox/NOX2 or POLDIP2/NOX4 and contrasted Ang II contractions in CAs with Affs.MethodsMice fed high salt were infused with Ang II (1000 ng ·Kg−1 · min−1 sc) or implanted with DOCA (vs sham procedures) for 4 weeks. The MAP of these mice was increased >25 mmHg. Intraparenchymal CAs were isolated from within the frontal cortex and Affs from the outer renal cortex. Vessels were perfused at 40 mmHg and tested with graded Ang II (10−12 to 10−6 M) vs vehicle.ResultsCAs from hypertensive mice had > 50% enhanced expression of p47phox and > 50% reduced expression of SOD1 and 3 but unchanged POLDIP2 and NOX4. CAs from sham mice failed to contract even with the highest concentration of Ang II (10−6 mol · l−1; change in diameter 0 ± 0%) whereas Affs contracted strongly. Ang II contractions were evoked by Ang II in CAs from hypertensive mice infused with Ang II (−7 ± 2%; P < 0.01) or implanted with DOCA (−18 ± 3%; P < 0.01) whereas contractions in Affs were unchanged. However, preventing hypertension with hydralazine, hydrochlorothiazide and reserpine reduced Ang II contractions in Ang II infused mice (−2 ± 0 vs −7 ± 1; P < 0.01) or DOCA mice (−4 ± 1 vs −18 ± 3; P < 0.01). Enhanced Ang II contractions of CAs were prevented in Ang II infused p47phox −/− mice (−1 ± 1 vs −7 ± 3%; P < 0.05) but were maintained in Ang II infused POLDIP2 +/− mice (−7 ± 1 vs −7 ± 3%; NS).ConclusionThe protection of CAs from Ang II contractions breaks down during hypertension per se because of enhanced expression of p47phox/NOX2 and reduced expression of SODs rather than POLDIP2/NOX4 highlighting targets for cerebral protection from hypertensive damage or dementia.
Hypoxia increases endothelin‐1 production via Hif1α in adipocytes
Authors: Rivera-Gonzalez Osvaldo , Stapel Jennifer , Speed Joshua S. 
Published: April 2020

Severe obesity causes a state of adipose tissue hypoxia and low blood flow. Both human and rodent visceral adipose tissue have been shown to have low oxygen tension (~15mmHg PO2) and increased levels of hypoxia inducible factor alpha (Hif1α), a prominent transcription factor in response to hypoxic conditions. Hif1α has been shown to increase endothelin‐1 (ET‐1) levels at the transcriptional level in endothelial cells. Obesity is associated with high circulating levels of ET‐1, which plays an important role in energy metabolism and insulin signaling when acting on the ET‐1 type A and B receptors on adipocytes. Therefore, the goal of this study was to determine whether hypoxia increases ET‐1 expression in adipocytes via Hif1α and inhibits insulin signaling. We utilized 3T3‐L1 murine fibroblast (passage 3–4) differentiated into adipocyte like cells. Exposure of 3T3‐L1 adipocytes to hypoxia (5% O2) for 24 hours led to a significant 3‐fold increase in ET‐1 mRNA compared to normoxic control cells (21% O2). Associated with increased ET‐1, hypoxia reduced insulin mediated glucose uptake and glycerol release compared to normoxic cells (148.8±16.4 vs. 237.6±24.4 glucose, 83.17±0.6 vs. 93.22±2.8 glycerol percent of control). In a separate experiment, 6‐hour exposure of 3T3‐L1 adipocytes caused a significant increase in ET‐1 and Hif1α mRNA (25.5±2.5 vs. 77.5±7.09 ET‐1, 2117±235.5 vs. 5015±370.2 Hif1α copies/50ng of RNA). Inhibition of Hif1a with either IDF‐11774 (1,25, and 50uM) or GN 44028 (1,10,20 uM) resulted in a significant attenuation in ET‐1 mRNA in response to hypoxia (77.5±7.09 vs. 22.35±3.7 ET‐1, 5015±370.2 vs. 3569±223.5 Hif1α Copies/50ng of cDNA) in a dose dependent manner. These data suggest that a hypoxia promotes ET‐1 production in adipocytes via Hif1α and is associated with diminished insulin sensitivity, suggesting a potential mechanism by which adipose tissue hypoxia promotes insulin resistance in obese individuals.Support or Funding InformationR00HL127178, P206M104357
Trypanosoma Cruzi Induces Phospho‐proteome Profile in Primary Colon Epithelial Cells During Early Infection
Authors: Rayford Kayla JaMayha , Suman Shankar , Cooley Ayorinde , Rachakonda Girish , Villalta Fernando , Pratap Siddharth , Lima Maria Fatima 
Published: April 2020

Trypanosoma cruzi, an obligate intracellular protozoan parasite, is the etiological agent of Chagas Disease. Due to globalization, the disease is now present in all economically advanced countries of the world. About 30% of T. cruzi infected individuals will develop cardiac, neurological, and/or gastrointestinal pathology, particularly megacolon. Megacolon, one of Chagas disease major pathologies, is accompanied by gastrointestinal motility disorders that have been attributed to alterations in the number of interstitial cells of Cajal and enteric nervous system defects. The objective of this study is to begin to define early molecular mechanisms that contribute to chagasic megacolon that can be exploited for development of molecular intervention strategies. In order to do this, we challenged primary colon epithelial cells (HCoEpiC) with invasive T. cruzi trypomastigotes at different time points to decipher changes in levels of phosphorylated proteins. Using a proteome profiler Human phospho‐kinase array, we show that T. cruzi induced a unique phospho‐proteome profile. We validated the phospho‐kinase array data via immunoblotting and immunofluorescence. Modulators of host immune response such JAK2, STAT1, and NF‐kB showed increased activation. Increased phosphorylated levels of kinases such, as p‐Src and p‐Fyn and the Heat Shock protein (p‐HSP27) chaperone illustrate dysregulation of intracellular signaling. We found that p‐JNK and p‐AKT exhibited increased phosphorylation and their downstream effectors p‐CREB and p‐c‐Jun showed increased nuclear colocalization. Early infection also induced increase thrompsopondin‐1 expression, a known fibrogenic protein. We generated a biological interaction network using Ingenuity Pathway Analysis (IPA) to further characterize protein‐protein interactions within the phospho‐proteome profile. In conclusion, we demonstrate a unique phospho‐proteome profile induced by T. cruzi during early infection of HCoEpiC and illustrate biological networks and signal transduction pathways that are activated during infection.Support or Funding InformationThis work was supported by NIH grants SC1AI127352, 5U54MD007586 (The RCMI Program in Health Disparities Research), and 5R25GM059994‐19 (RISE).
K48 Linked Ubiquitin Chains Affect Proteasomal Unfolding Ability via Interactions with Rpn10
Authors: Boscia Joseph Anthony , Hughes Danielle J. , Kraut Daniel Adam 
Published: April 2020

The ubiquitin proteasome system plays a crucial role in homeostasis by preferentially degrading proteins that are damaged, misfolded, or no longer necessary in regulatory processes. Substrates are recognized and polyubiquitinated by E1, E2, and E3 enzymes, which leads to recruitment and degradation by the proteasome. However, the proteasome does not always completely degrade its target and will release a protein fragment if unfolding does not occur. We previously showed that the proteasome’s unfolding ability is dependent on the ubiquitin chains’ interactions with proteasomal ubiquitin receptors, and that different chain architectures (linear K63 chains vs branched K48 and K63‐containing chains) had different receptor dependencies. To investigate the interaction of substrates bearing linear K48‐linked chains, we turned to the E3 ligase Ubr1, which recognizes N‐end rule substrates. A model unfolding ability substrate containing an N‐terminal arginine was degraded by wild‐type and ubiquitin‐receptor mutant proteins. The results indicate that although ubiquitin receptors Rpn1, Rpn10, and Rpn13 are all important for degradation of this substrate, Rpn10 has the greatest effect on the proteasome’s unfolding ability.Support or Funding InformationThis material is based upon work supported by the National Science Foundation under Grant No. 1515229 to DAK.
Synaptic circuit restoration and functional recovery in the mouse visual cortex after ischemic injury and direct in vivo reprogramming of astrocytes into neurons
Authors: Chubykin Alexander , Tang Yu , Wu Qiuyu , Ryu Esther , Pei Zifei , Chen Yuchen , Chen Gong 
Published: April 2020

Ischemic injury caused by stroke is one of the leading causes of severe morbidity and mortality. Neuronal loss, proliferation of reactive astrocytes and the formation of a glial scar represent the three critical problems preventing the functional recovery. Direct reprogramming of astrocytes into neurons in vivo using NeuroD1‐containing AAV virus represents a new promising gene therapy capable of replenishing the neuronal population and reducing gliosis. We have used NeuroD1‐containing AAV virus to convert astrocytes into neurons in the mouse primary visual cortex (V1) following focal ischemic injury. We have demonstrated that this in vivo reprogramming can restore visual evoked potentials (VEPs) and individual neuronal responses impaired after ischemic injury in V1. We have used Channelrhodopsin Assisted Circuit Mapping (CRACM) to demonstrate that this functional restoration is accompanied by the integration of the newly reprogrammed neurons into the visual microcircuit and reestablishment of the specific interlaminar long‐range connections. Our work suggests that in vivo NeuroD1‐based viral therapy can convert reactive astrocytes into neurons and restore visual function lost after local ischemiaSupport or Funding InformationPurdue Research Foundation
The Use of Biometrics and Rubric Analysis to Assess How Students View, Cognitively Process, and Respond to 3D Physical Molecular Models in Undergraduate Biochemistry
Authors: Terrell Cassidy R. , Freeman Sienna , Calvert Jenifer , Randolph Adriane , Cortes Kimberly Linenberger 
Published: April 2020

Among the STEM disciplines biochemistry curricula present a particular challenge to students with abstract concepts that can lead to rampant and resistant misconceptions impeding learning and therefore impact retention. Moreover, research has shown two‐dimensional representations not only fail to effectively convey biochemical concepts, but also propagate misconceptions. In particular, research has shown students have significant difficulty understanding enzyme‐substrate relationships. One way instructors have suggested to support students while learning this content is through the use of 3D physical models of the enzyme and substrate. However, little research has been conducted on how the models impact the learning process and how to best design these models and corresponding activities. This presentation will describe an iterative design process based on biometric, observational and rubric data analysis. The biometric data is collected using electroencephalographic (EEG) and eye tracking tools and voice recordings from simulated learning environments where biochemistry students completed a serine protease activity with corresponding physical models. These results offer insights into how students view and cognitively process activities using physical models with respect to how the instructor intends students to learn with and use these tools. In addition, observational and rubric analyses of student responses to activities from the simulated learning environment and real classroom sessions provide further data for the iterative activity design process.Support or Funding InformationThis project is supported by the National Science Foundation under award number IUSE 1711402/1711425 to University of Minnesota, Rochester and Kennesaw State University.
Comparison of effectiveness of case‐based teaching and traditional teaching method in preparing students for board exam USMLE Step 1
Authors: Nayakanti Abraham R.J. , Arja Sireesha Bala , Arja Sateesh Babu 
Published: April 2020

The introduction of an interactive student‐centred and self‐directed approach in medical education has changed the way students learn. Scientific literature demonstrated the effectiveness of group discussion for greater understanding and retention of materials, when compared to traditional teaching. Teaching and learning in an active way, develop problem‐solving, critical thinking, and reasoning skills will help the students to become better doctors in the future. This study aims to find out the effectiveness of learning in terms of students reaching milestones of learning objectives in Histology part of Human structure and function course in an integrated curriculum with both case‐based learning and traditional teaching methods.This is a randomized experimental study. Students are divided into two small groups. Each group had 7 students. One group (Group A) received the case‐based discussion on the topic of esophagus and another group( Group B) received the traditional teaching method on the same topic. For the other topic on kidney of urinary system Group A received the traditional method of teaching and Group B received the case‐based teaching. Students performance in assessments for these topics were measured using knowledge‐based questions of clinical vignettes. The questions used were same as USMLE style.We analyzed the performance of students by using two‐tailed t‐test. The results were better with with case‐based discussions as the students have already gone through simulated situations.Support or Funding InformationAmerican Association for Anatomists
Melanocytes in the Leptomeningeal Region of Fetal Sheep Cerebral Cortex: Response to Exposure to Bacteria
Authors: Fohn Alexis , Wood Charles E. 
Published: April 2020

Over the past several decades, there has been growing evidence in support of the in utero colonization hypothesis, stating that womb is not sterile and that low levels of bacteria may be found in fetal tissues without harming the fetus. Exposure of the fetus to bacteria would likely stimulate an immune response. Melanin, produced in the brain by several cell types, may play a role in the inflammatory response as it does in the epidermis. Melanocytes are phagocytic cells that synthesize melanin and are thought to function in response to inflammation. We hypothesize that we can find melanocytes in fetal brain tissues, and that their numbers are increased in fetuses exposed to bacteria. We assessed tissues from 31 fetal sheep that were catheterized and exposed to experimental manipulation (n=23) or were non‐catheterized (naïve; n=8). Identified histologically using Fontana‐Masson stain and quantified as number of cells in a 40x field (10 fields/animal), we found melanocytes in the leptomeningeal region of all fetuses. There was a higher presence of (leptomeningeal) melanocytes in catheterized animals compared to non‐catheterized animals (25±4 vs 3±1 cells/field) per 32,000 um2. We conclude the leptomeningeal melanocytes in the fetal cerebral cortex are part of the fetal innate immune response to exposure of the fetus to pathogen‐associated molecular patterns.Support or Funding InformationNIH Grant HD033053
Two-Year Delayed Healing of an Endovascular Access Site Related to an Unusual Etiology
Authors: Bohanon Carol Jeorg , Kiemele Lester James 
Published: April 2020

ABSTRACT
In this case report, the authors describe a patient who underwent an endovascular abdominal aortic aneurysm repair complicated by more than a 2-year delay in healing of the left inguinal fold access site. Providers initially suspected a chronic infection or foreign body reaction, but eventually the patient was diagnosed with superficial granulomatous pyoderma. Once the correct etiology was determined and appropriate treatment begun, the access site healed within 3 weeks.
Construction and Validation of an Instrument for Assessing the Feet of Persons with Diabetes
Authors: da Costa Saulo Pereira , Chavaglia Suzel Regina Ribeiro , Ohl Rosali Isabel Barduchi , Costa Bruna Yara , Barbosa Maria Helena , Woo Kevin , Gamba Mônica Antar 
Published: April 2020

ABSTRACT

OBJECTIVE
To construct and validate an assessment instrument to evaluate the feet of people with diabetes mellitus in Brazil.

METHODS
Methodological research developed in three stages: construction of the Assessment Instrument for the Feet of People with Diabetes Mellitus, validation of face and content validity, and field research with 131 participating patients. The Pearson (r) and Spearman correlation coefficients (ρ) were used for criterion validity. To test reliability, the internal consistency of the Cronbach α domains was evaluated and simple κ, weighted κ, and intraclass correlation coefficients for interobserver evaluation were determined.

RESULTS
The instrument demonstrated validity and reliability. The content validity index represented a high internal consistency (α > .70). The interclass correlation coefficient was high (>0.98). The Pearson (r) and Spearman (ρ) correlation tests confirmed a correlation between the two variables.

CONCLUSIONS
The instrument was valid and reliable for assessing the feet of people with diabetes mellitus in Brazil. Future studies should identify the cut off point for the diagnosis of neuropathic and vascular impairment of the feet of diabetic persons through appropriate statistical methods.
Temporary Transvenous Diaphragmatic Neurostimulation in Prolonged Mechanically Ventilated Patients: A Feasibility Trial (RESCUE 1)
Authors: Ataya Ali , Silverman Erin P. , Bagchi Aranya , Sarwal Aarti , Criner Gerard J. , McDonagh David L. 
Published: April 2020

Objectives:
Prolonged mechanical ventilation promotes diaphragmatic atrophy and weaning difficulty. The study uses a novel device containing a transvenous phrenic nerve stimulating catheter (Lungpacer IntraVenous Electrode Catheter) to stimulate the diaphragm in ventilated patients. We set out to determine the feasibility of temporary transvenous diaphragmatic neurostimulation using this device.

Design:
Multicenter, prospective open-label single group feasibility study.

Setting:
ICUs of tertiary care hospitals.

Patients:
Adults on mechanical ventilation for greater than or equal to 7 days that had failed two weaning trials.

Interventions:
Stimulation catheter insertion and transvenous diaphragmatic neurostimulation therapy up to tid, along with standard of care.

Measurements and Main Results:
Primary outcomes were successful insertion and removal of the catheter and safe application of transvenous diaphragmatic neurostimulation. Change in maximal inspiratory pressure and rapid shallow breathing index were also evaluated. Eleven patients met all entry criteria with a mean mechanical ventilation duration of 19.7 days; nine underwent successful catheter insertion. All nine had successful mapping of one or both phrenic nerves, demonstrated diaphragmatic contractions during therapy, and underwent successful catheter removal. Seven of nine met successful weaning criteria. Mean maximal inspiratory pressure increased by 105% in those successfully weaned (mean change 19.7 ± 17.9 cm H2O; p = 0.03), while mean rapid shallow breathing index improved by 44% (mean change –63.5 ± 64.4; p = 0.04).

Conclusions:
The transvenous diaphragmatic neurostimulation system is a feasible and safe therapy to stimulate the phrenic nerves and induce diaphragmatic contractions. Randomized clinical trials are underway to compare it to standard-of-care therapy for mechanical ventilation weaning.