bluuebunny/crossref_metadata_2025 huggingface dataset:
Let Students SOAR: Impact of Early Clinical Interactions on Perceptions of Specialties & Anatomy
Authors: Royer Danielle , Carmichael Heather , Kondo Kimi , Lee Lisa , Gritton Cory Buenting
Published: April 2020

The University of Colorado incorporated Structured Obligatory Application & Review (SOAR) sessions into the medical anatomy block. SOAR sessions, spaced across the block, used small group work with activities focused on anatomical content and clinical integration in 4 interactive rotations. The rotations included Challenge Grid: team‐based learning of board‐style questions; Every Body Has Embryology: relating embryology to gross; Bedside Anatomy: cadaver‐side surgical cases; Anatomy of Imaging & Physical Exam: anatomic correlates of imaging & physical exam. Each rotation included peer‐to‐peer teaching facilitated by clinical (surgical and radiology) and anatomical (gross & embryology) experts. The study objective was to evaluate SOAR session impact on student perceptions of surgery and radiology specialties, along with views of gross anatomy and embryology value.

In an IRB exempt study, 1st year medical students (n=184) in 2019 were invited to complete an online pre‐survey before the first SOAR session and paper post‐survey in the last SOAR session. The pre‐survey questions included Likert perception and prior experience questions on surgery (n=3), radiology (n=3), gross (n=2) and embryology (n=2). The post‐survey contained Likert perception items on surgery (n=1), radiology (n=1), gross (n=1) and embryology (n=1), as well as perceived SOAR effect on views of clinicians (n=2), specialty career interest (n=2), clerkship preparedness (n=2), and gross & embryology importance (n=2).

Online pre‐survey response rate was 13% (n=23) and paper post‐survey response rate was 81% (n=149). Post‐survey analysis showed 45% of students considering a surgical specialty, 53% reporting increased surgical interest after Bedside Anatomy, and 84% agreeing Bedside Anatomy positively influenced views of surgeons. However, only 34% reported Bedside Anatomy increased their preparedness for surgery core clerkship. While only 21% of students report considering radiology as a specialty, the Anatomy of Imaging SOAR increased interest in a radiology career for 71% of students, and 48% believed the session positively influenced their views of radiologists and increased their preparedness for clerkships. Gross and embryology were perceived important in medical education (95% and 67% respectively), with SOAR reported as enhancing student appreciation of gross (79%) and embryology (50%). Matched pre and post‐survey responses (n=23; 13% response rate) were compared measuring SOAR impact on specialty consideration and gross/embryology importance. Although student perceptions were not significantly different after SOAR participation, an increasing positive trend in surgical/radiology career perceptions and gross anatomy importance was seen. Thematic analysis completion may give insights on impacts of early, meaningful clinical integration on specialty choice and views on anatomical sciences.
Resurrection of Ancestral Aspartyl‐tRNA Synthetases
Authors: McDaniels Arianna , Sheppard Kelly
Published: April 2020

Protein synthesis is essential for life and requires the correct pairing of amino acids to their cognate transfer tRNA by aminoacyl‐tRNA synthetases. Many prokaryotes lack an AsnRS to directly attach Asn to tRNAAsn. Instead these organisms use a non‐discriminating AspRS to attach Asp to tRNAAsn and GatCAB to amidate the Asp to Asn. Organisms with an AsnRS often have a discriminating AspRS (D‐AspRS) that only attach Asp to tRNAAsp. How that specificity evolved from a bacterial ND‐AspRS is unknown. To address, we phylogenetically modeled the last common ancestor of D‐AspRS of gamma‐proteobacteria and its most closely related ancestral gamma‐proteobacterial ND‐AspRS. We report on the overproduction and purification of the ancestral enzymes to study how specificity evolved. The work will provide insight into the evolution of tRNA specificity and tools for synthetic biology.

Support or Funding Information

National Science Foundation (MCB‐1615770)
Role of RGS10 in the ovarian cancer microenvironment
Authors: Dean Phillip , Hooks Shelley
Published: April 2020

Ovarian cancer is the deadliest of gynecological cancers and is associated with a high rate of chemoresistance. The discovery of more effective treatments and new therapeutic targets in ovarian cancer requires disease models that better represent the tumor microenvironment and account for dynamic crosstalk between multiple cell types. Macrophages, one of the most abundant immune cells in the tumor microenvironment, are actively recruited into the tumor and can accelerate tumor progression and chemoresistance via the production of inflammatory mediators. Recently, our lab and others have established Regulator of G protein Signaling 10 as a key regulator of inflammatory signaling in both macrophages and ovarian cancer cells. RGS10 robustly regulates macrophage activation and polarization by suppressing the production of inflammatory cytokines TNF‐α and IL‐6. Further, RGS10 suppresses the activation of cyclooxygenase‐2 (COX2) expression in both ovarian cancer cells and macrophages. However, the regulatory role of RGS10 in the tumor microenvironment where macrophages and ovarian cancer cells have direct interaction has not been explored, and it is not known if RGS10 regulatory roles in these distinct cell types will be synergistic or oppositional. Further, RGS10’s role in cancer progression has not been investigated in an in vivo tumor xenograft model with an intact macrophage population. The current study employs both an in vitro co‐culture model of macrophages and ovarian cancer cell lines and an in vivo syngeneic ovarian tumor model using mouse ID8 ovarian cancer cells to define the role of RGS10 in inflammatory signaling between immune and tumor cells in the ovarian cancer microenvironment.

Support or Funding Information

Marsha Rivkin Foundation, University of Georgia
Integrated Group Study with Lecture in Teaching Sensory and Motor Pathways in Cross‐sectional Anatomy
Authors: Zhou Yuxin
Published: April 2020

Introduction

First year dental students are trained to interpret clinical presentations of injuries on brainstem or spinal cord. Therefore, it is necessary for them to understand the three major sensory and motor pathways (dorsal column/medial lemniscal system, anterolateral system, corticospinal tracts) that go through brainstem and spinal cord, including their functions and cross‐sectional anatomy.

Aim

The present lesson was designed for first year students at Boston University School of Dental Medicine to learn the three sensory and motor pathways by using cross‐sectional figures of brainstem and spinal cord, and help students to apply the knowledge in clinical cases.

Methods

Three sessions with the same contents were held on two days. Two sessions were held on the first day containing 30 students in total, and the last session was held on the fifth day containing 20 students. The lesson started with a pre‐quiz, and then students worked in groups of 4 to 5 people to order cross‐sectional figures of brainstem and spinal cord. Then, the instructor gave a lecture to explain the answer, followed by a brief review on sensory and motor pathways. In the second group activity, students were asked to label the three pathways on the cross‐sectional figures. In the third group activity, students were given the location of a lesion on brainstem, and then were asked to discuss the potential clinical presentations. Instructor explained the answers after each activity. At the end, students took a post‐quiz. Both pre‐quiz and post‐quiz had a full score of 5, containing 2 questions on clinical cases, 1 question on pathway, 2 questions on cross‐section anatomy. All questions were multiple choice. The levels of difficulty in two quizzes are similar.

Results

The average scores from pre‐quiz and post‐quiz were compared by conducting a t‐test. Students showed significantly improvement in the post‐quiz as compared to pre‐quiz (pre: 1.50+/−1.07; post: 3.12+/−1.05; p<0.00001). Both pre and post scores of students attending on the fifth day were significantly higher as compared to the pre and post scores of students on the first day (pre: day1=1.20; day5=1.95; p=0.01; post: day1=2.76; day5=3.65; p=0.003). A t‐test was conducted to compare group differences of the improvements (first day vs. fifth day). Improvements of students were defined as the differences between post and pre‐quiz scores, and the improvements were not significantly different based on the day of the session (p=0.69).

Conclusion

Students showed significant improvement in understanding cross‐sectional anatomy of three major sensory and motor pathways after group study integrating with lectures. In addition, the effectiveness of this teaching methods was not affected by the baseline scores of students.
Blood Oxygen Stores of Olive Ridley Sea Turtles, Lepidochelys olivacea are Highly Variable Among Individuals During Arribada Nesting
Authors: Arango B. Gabriela , Melendez Martha Harfush , Crocker Daniel E.
Published: April 2020

A key difference among marine divers is whether or not they make use of their lung O2 stores while diving. Sea turtles are air‐breathing divers that dive with their lungs full of air. Lung oxygen stores in sea turtles are supplemented by O2 stored in the blood. Olive ridley sea turtles exhibit polymorphic nesting behaviors consisting in either a mass nesting behavior called arribada, where up to 25,000 turtles nest at once, or a solitary nesting behavior. We measured blood volume, hemoglobin concentration, hematocrit, plasma volume and mean corpuscular hemoglobin concentration, and estimated total blood O2 stores in samples collected from olive ridley turtles nesting solitarily or in arribada. There were no significant differences in mean values between nesting periods, but most parameters were more variable in arribada nesting individuals than in those performing solitary nesting. Mass‐specific plasma volume did not vary among individuals but mass‐specific blood volume and blood oxygen stores varied widely, 2‐fold and 3‐fold, respectively. Blood O2 stores represented 32% of total body O2 stores. Under typical mean diving conditions of 26°C and high levels of activity, blood stores can confer ~14 minutes of aerobic dive times and are likely critical for the long duration, deep diving exhibited by the species. Individual differences in blood O2 stores strongly impact estimated aerobic dive limits and may constrain the ability of individuals to respond to changing ocean temperatures.

Support or Funding Information

McNair Scholars and Centro Mexicano de la Tortuga
Regulation of Cellular Proliferation and Migration by Palmitoylation of the Na+‐H+ Exchanger Isoform 1 (NHE1)
Authors: Kooiker Amanda J. , Wallert Mark A.
Published: April 2020

The Na+‐H+ Exchanger Isoform 1 (NHE1) is an important factor in cellular proliferation and migration of cells in both healthy and diseased tissues. NHE1 has been extensively studied in cancer biology, as activation of NHE1 contributes to the inversion of the pH gradient that is characteristic of the transformation from healthy function to a tumorigenic state. NHE1 is a 12‐pass transmembrane protein consisting of 815 amino acids. The N‐terminal transport domain resides in the plasma membrane and exchanges a single extracellular sodium ion for one intracellular hydrogen ion. NHE1 also has an extended C‐terminal cytoplasmic tail that function as the transporters regulatory domain. The cytoplasmic regulatory domain includes an extensive series of binding motifs for proteins and lipids as well as numerous phosphorylation sites. Recently, it was recognized that NHE1 also undergoes reversible palmitoylation. We hypothesize that this palmitoylation may be utilized to regulate NHE1 activation, thereby regulating cell proliferation and migration. In order to evaluate the role of palmitoylation, 2‐bromopalmitate (2BP), an inhibitor for palmitoylation, along with ethyl‐isopropyl‐amiloride (EIPA), which acts as an inhibitor for NHE1, will be employed in migration and proliferation assays in Human Embryonic Kidney cells (HEK293). CRISPR‐Cas9 technology will also be used to create a knock‐out version of this cell line (HEK293NHE1KO). Further analysis with then be performed to assess effects of palmitoylation in the absence of NHE1. We hypothesize that inhibition of endogenous NHE1 activity and lack of cellular palmitoylation will decrease the potential for growth and migration.
The importance of mediolateral forces on foot rehabilitation after injury
Authors: Lautzenheiser Steven G. , Sylvester Adam D. , Kramer Patricia Ann
Published: April 2020

Displaced fractures of the foot and ankle take considerable time to heal. Throughout this rehabilitation period, the goal is to provide sufficient stimulus to the bone to prevent bone loss while limiting the chance of re‐injury. Both of these goals require understanding the ground reaction forces (GRFs) applied to the foot while walking. Most understanding of the forces to which bones of the foot are subjected is premised on data developed from force plates in laboratories that evaluate movement. The coordinate system of force plates is typically aligned with the physical surroundings as well as the coordinate system of motion capture equipment to create a world coordinate system (WCS). This WCS also aligns with most skeletal elements and joints. The anatomical directions of the foot, particularly during walking, do not necessarily match up to these primary axes. The degree to which foot placement impacts the internal forces and moments of the foot and ankle remains unclear; however, the variation of foot placement has the potential to substantially change internal forces. Consequently, the purpose of this work is to determine if forces aligned in a foot coordinate system (FCS) differ from those in the WCS in order to inform orthopedic treatment and rehabilitation.

Twenty participants were recruited to walk unshod for this study. Kinematic and kinetic data were collected using an eight‐camera Qualisys system with four Kistler force plates. The FCS, which tracks the orientation of foot as it moves through space, was calculated from the position of the heel and first and fifth metatarsal heads. GRFs were translated and rotated from WCS to FCS using custom‐developed MatLab code. Proximodistal, mediolateral, and superioinferior forces were compared between WCS and FCS. In FCS, mediolateral forces developed during the propulsive phase are 150–200N larger than in WCS (p<0.001), and the maximum mediolateral force is directed toward the centerline of the body in WCS, while in FCS it is directed laterally.

Rotating the GRF into FCS produces a different picture of internal forces than is usually understood from WCS. Typically, mediolateral forces are considered less consequential when considering treatment for foot and ankle injuries. These data show that mediolateral forces (relative to the foot) are larger than previously understood. Injuries that are sensitive to these mediolateral forces include metatarsal fractures, Lisfranc injuries, talar neck fractures, and distal fibular fractures, among others. Implants and interventions used to stabilize these injuries should take into consideration these forces including potential modifications to the rehabilitation protocol.
Use of PeerWise in a Graduate Physician Assistant Pharmacology Course
Authors: Guillory Ashley Nicole
Published: April 2020

There are multiple studies that indicate that generating and answering questions can be very beneficial to students in developing analytical skills as well as providing study resources especially for students in health profession programs. Students enrolled in a first‐year Clinical Pharmacology course in a graduate‐level Physician Assistant course were required to write forty multiple choice questions in the PeerWise platform over the course of the semester. Additionally, they were required to answer a minimum of eighty questions submitted by their peers. The students were given detailed instructions on what were acceptable questions. They were also required to include a rational for the correct answer and list a resource that confirmed the correct answer. Upon taking a question, students are required within the program to rate whether they agree with the author’s answer, the level of difficulty of the question, and the quality of the question. Students’ scores for question authoring, answering, rating, and total answers correct were correlated to exam grades. Students’ with lower performance on exams were shown to either not have accessed the PeerWise platform prior to the exam or had reduced interactions with the platform compared to students with higher performance. According to the end‐of‐course evaluation, most students felt that using the platform was useful and helped them to test their understanding of the material.
Lipid profile and liver lipids of OLETF rats during ARB treatment and after its removal
Authors: Godoy-Lugo Jose Arquimides , Lee Debby , Thorwald Max Andrew , Hui David , Nakano Daisuke , Nishiyama Akira , Ortiz Rudy M.
Published: April 2020

The metabolic syndrome (MetS) affects 20% of the US population. MetS comprises several disorders that raise the risk of atherosclerosis, insulin resistance, and diabetes. Angiotensin receptor blockers (ARBs) are used to ameliorate hypertension associated with metabolic disorders. Nonetheless, the potential benefits of ARBs on the metabolic state are not fully appreciated. ARB treatment reduces overproduction and accumulation of hepatic triacylglycerols (TAG), but whether ARB treatment has favorable effects in fatty livers associated with insulin resistance is still unknown. Furthermore, the compliance on the usage of ARBs should also be addressed, as MetS patients may be under variating treatments, exposing them to secondary effects due to the ARB treatment removal. To evaluate the benefits of ARB treatment and implications of its removal on the lipid profile, four groups (n=4–6) of 25‐week‐old rats were used: (1) lean, strain‐control Long‐Evans Tokoshima Otsuka (LETO), (2) obese, insulin resistant Otsuka Long‐Evans Tokoshima Fatty (OLETF), 3) ARB‐treated OLETF, (10 mg olmesartan/kg/d × 8 wks), and 4) OLETF ± ARB (10 mg olmesartan/kg/d × 4 wks then removed until dissection). An oral glucose challenge (GC) was performed prior to dissection and tissues collected from a subset of animals in each group at defined time points (T0, 3 an 6hr). We measured different components of the lipid profile, during the ARB treatment and after its removal. Plasma NEFA, TAG and cholesterol levels remain unchanged with ARB treatment, as well as with ARB removal. ARB treatment did not change the liver levels of cholesterol, but prevented the increase shown by OLETFs during the GC. ARB removal shown increased cholesterol after 6 hr of the GC. ARB treatment decreased liver TAG and throughout the GC. ARB removal increased TAG liver levels during the GC. Suggesting that lipid profiles may not change during static sampling during or after ARB treatment. ARB treatment reduces liver TAG concentration, and even with ARB removal suggesting that plasma levels do not accurately reflect tissue levels. Following the GC, the ARB removal group demonstrated an increase in levels, suggesting that treatment non‐compliance results in rapid return to basal levels and increased potential for hepatic dysfunction. Further investigation on lipid transport and metabolic regulation during ARB treatment and removal may yield insight for a wider perspective for treatment of traits linked to MetS.

Support or Funding Information

This work was supported by NIH MHIRT.
Anti‐hypertensive Effects of Whey Protein Supplementation in Women with Polycystic Ovarian Syndrome
Authors: LeMieux Monique J. , Zumbro Emily L. , Rao Manisha , Balcom-Luker Shenavia , Kaiser Kayleigh , Low Irene , Broughton K. Shane
Published: April 2020

Polycystic Ovarian Syndrome (PCOS) is the most common female endocrine disorder and a leading cause of female infertility affecting about 5 million women of reproductive age in the US. It is characterized by metabolic dysfunction, abnormal hormonal pattern, hyperandrogenism, insulin resistance (IR), dyslipidemia and an inflammatory state. In addition, PCOS women have an increased risk of developing type 2 diabetes (T2DM), hypertension (HTN) and heart disease. One of the most significant factors associated with HTN is increased circulating angiotensin II (Ang II). Ang II is a pro‐inflammatory factor produced by adipose tissue and has been implicated in linking obesity, inflammation and IR. Metabolites generated as result of whey protein digestion improve insulin sensitivity, inhibit ACE (an enzyme responsible for production of Ang II) thereby playing an important role in the prevention of HTN and associated cardio‐vascular pathologies. These benefits of whey protein ingestion have been demonstrated in normal populations and in individuals with T2DM. The purpose of this study was to examine changes in blood pressure (BP), Ang II and Adiponectin concentrations following 40 days of whey protein supplementation and to examine differences in baseline measurements of between body fat distribution in PCOS women and healthy controls (CON). Women with PCOS and CON were recruited from Texas Woman’s University (TWU) and asked to consume 35g of whey protein for 40 days. Baseline, Day 20 and Day 40 concentrations were measured via plasma and serum collection. Resting BP (Systolic and Diastolic pressures; SBP and DBP respectively) were measured with an electronic monitor were used to calculate mean arterial pressure (MAP) at baseline, Day 20 and Day 40. DXA was used to estimate body composition and fat distribution (total body fat, trunk fat and Android: Gynoid fat ratio [A:G]) at baseline. Protocols used in this study were approved by TWU’s Institutional Review Board (IRB). Preliminary analyses indicates that at baseline SBP was significantly lower in the CON group compared to PCOS. However, DBP and MAP had no significant differences at baseline. The PCOS group also had lower adiponectin levels at baseline when compared to the CON group. Ang II concentrations, as well as Day 20 and Day 40 analysis are currently being evaluated. Overall, our results indicate that vascular health is compromised in young women with PCOS compared to health controls. Results from this research, will not only help provide a better understanding of the link between inflammatory markers such as Ang II and the increased risk of HTN commonly seen in women with PCOS, but it also provide a nutritional intervention to help prevent these disorders.

Support or Funding Information

Glanbia Nutritionals, Inc., TWU Research Enhancement Program, TWU Human Nutrition Research funds.
Regulation of compensatory synaptic plasticity in inactive motor neurons of overwintering bullfrogs, Lithobates catesbeianus
Authors: Zubov Tanya , Santin Joseph M.
Published: April 2020

Circuits must maintain stable electrophysiological function to produce behaviors. If neurons face a disturbance, such as changes in activity or environmental perturbations, they often compensate by altering synaptic and intrinsic properties to oppose the challenge, a type of plasticity termed “homeostatic plasticity.” Although homeostatic forms of plasticity are thought to maintain stability in the healthy nervous system, abnormal challenges using drugs, sensory deprivation, and injury have generated most of our mechanistic understanding of these processes. This has led to questions of how animals regulate these mechanisms physiologically in vivo. American bullfrogs, Lithobates catesbeianus, normally breathe often, but during months of aquatic overwintering the respiratory network is completely silent, representing a large and natural challenge to neuronal function. We recently showed that respiratory motor neurons use a classic type of synaptic homeostasis that compensates for inactivity during overwintering which regulates motor output from the network after months under water (Santin et al. 2017, eLife). Current models of homeostatic plasticity predict that neurons continuously increase synaptic strength during inactivity, but whether synaptic strength increases in a graded fashion or rises quickly and then plateaus during winter inactivity is unknown. To test this, we measured spontaneous postsynaptic AMPA receptor currents in respiratory motor neurons in brainstem slices that innervate the laryngeal dilator from frogs maintained at ~21°C (n=13) or those that had been cold (~1–2°C) and submerged for 2 (n=21) and 4 weeks (n=20). Consistent with our previous work, we found that cold submergence increased the postsynaptic amplitude and charge transfer (amplitude, p=0.004; charge transfer, p=0.0004; Kruskal‐Wallis test); however, increases in postsynaptic function did not differ between frogs cooled for 2 and 4 weeks (p>0.05 for amplitude and charge transfer; Dunn’s multiple comparisons test). Frequency of postsynaptic events did not differ between warm and cold‐submerged frogs, indicating that cold‐acclimation does not influence spontaneous and/or action potential‐driven transmitter release. Thus, postsynaptic strength increases relatively soon after entry into the overwintering environment and is likely maintained at a single, compensated level over long time scales. In contrast to theoretical work that suggests neurons may continue to compensate until they return to a homeostatic set point, our work shows that the amount of compensation may be tuned to meet future demands of the network (i.e., appropriate breathing) or constrained by limitations imposed by the environment.

Support or Funding Information

This work was funded by start‐up funds from UNC‐Greensboro to JS.
The Problem of Estimating Tissue Perfusion from Observations of Microvascular Flow
Authors: Secomb Timothy W. , Celaya-Alcala Jose T. , Boas David A. , Sakadžić Sava
Published: April 2020

The perfusion of a tissue region is defined as the blood flow rate to the region divided by its volume. For a whole organ, this definition is unambiguous, but a problem arises for small tissue regions, with many microvessels crossing the boundaries. The total inflow rate is approximately proportional to the surface area of the region. If this inflow rate is used to estimate the perfusion, the result is approximately proportional to the surface‐area‐to‐volume ratio, and yields unrealistically high estimates for small regions. How, then, should tissue perfusion be estimated from observations or simulations of blood flow in small tissue regions? The discrepancy arises because any flow pathway that passes through a small tissue region also contributes to perfusion of regions upstream and/or downstream. Therefore, the flow on that pathway should be only partially attributed to the given region. Here, a method is proposed for estimating perfusion in a region of tissue. The blood flow on any pathway through the region is attributed to the region in proportion to the decline in blood oxygen content that occurs in the region, divided by the overall decline from arterial to venous oxygen content. If the chosen region is representative of the tissue with regard to oxygen consumption rate, then the local perfusion computed by this method is equal to the overall tissue perfusion. Implementation of this method requires simulation of oxygen transport in the microvascular network supplying the region, which can be done efficiently using a Green’s function method. In these simulations, boundary segments are classified as arterioles, capillaries and venules, and outflow oxygen levels in each category are used to define inflow oxygen boundary conditions. When applied to a network from the mouse cortex containing 4908 segments, this method yields estimates of perfusion consistent with whole‐organ values, resolving the discrepancy between microscale and macroscale estimates. Tissue perfusion is closely related to the oxygen extraction ratio, which is a key determinant of tissue oxygen levels. Therefore, the estimation of tissue perfusion is an important step towards realistic assessment of the effects of microvascular network structure and blood flow on tissue oxygenation.

Support or Funding Information

Supported by NIH grant HL133362.
Glypican‐1 Plays a Cardiac Protective Effect During Heart Failure Induced by Pressure Overload
Authors: Cannon Marisa , Garcia Roxanne , Dull Randal O. , Carvalho-de-Souza Joao L. , Chignalia Andreia Z.
Published: April 2020

About 1 in every 4 deaths is due to heart disease. Specifically, heart failure in its different forms impacts about 5.7 million people in the U.S. Hemodynamic pressure overload is a known cause for heart dysfunction and it may culminate in heart failure. Glypican‐1 (Gpc1) is a heparan sulfate proteoglycan that has mechanosensitive properties. Its role on heart function is not well understood but it may play a role on cardiac response to increased pressure. Herein we sought to investigate if deletion of Gpc1 contributes to cardiac dysfunction in a model of heart failure induced by pressure overload (Transverse Aortic Constriction, TAC). CD1 (wild type, WT) and Gpc1 knockout (Gpc1KO) mice were submitted to either a sham or TAC procedure. Heart function was assessed by echocardiography (ECHO) before (baseline), three and five weeks post‐surgery. The parameters analyzed by the ECHO were: stroke volume, cardiac output, left ventricle mass, left ventricle anterior wall during diastole (LVAWd), left ventricle posterior wall during diastole (LVPWd), left ventricle mean wall thickness (WTd), eccentricity, heart rate and ejection fraction. Baseline ejection fraction and heart rate was similar between WT and Gpc1KO. Baseline stroke volume, cardiac output and WTd were increased whereas eccentricity was decreased in Gpc1KO. Gpc1KO showed increased susceptibility to heart failure as evidenced by a faster and steep decrease in ejection fraction when compared to WT. In addition, Gpc1KO uniquely showed decreased stroke volume and cardiac output after 5 weeks of TAC. Left ventricle size was increased and eccentricity was decreased in the same time‐frame for both lines. Taken together, these results indicate that Gpc1 has a protective effect on cardiac function in a model of heart failure caused by pressure overload.

Support or Funding Information

Department of Anesthesiology, College of Medicine, Tucson
Stimulation of AP evoke release of Ang II in the NTS detected by R‐GECO AT1R sniffer cells
Authors: Shimoura Caroline Gusson , Paundralingga Obed , Farmer George E. , Cunningham J. Thomas
Published: April 2020

The renin angiotensin system (RAS) signaling in the brain plays an important role in cardiovascular control and body fluid homeostasis. Although systemic angiotensin II (Ang II) can access the brain through circumventricular organs such as the subfornical organ (SFO), organum vaculosum of the lamina terminalis (OVLT) and area postrema (AP), the existence of a brain RAS is still controversial. Our previous studies have used angiotensin sensitive sniffer cells to test whether angiotensin peptides are released from brain slices containing the SFO projections to the median preoptic nucleus. Sniffer cells were produced by transfecting Chinese Hamster Ovary cells with commercially available plasmids for the angiotensin type 1a (AT1a) receptor (Origene Tech.) and R‐GECO (Addgene #32462). These sniffer cells are sensitive to angiotensin II and III but not angiotensin 1–7, bradykinin, or neurotransmitters such as glutamate or acetylcholine. In these studies, we examined another pathway involving the AP and nucleus of tractus solitarius (NTS). The AP is angiotensin sensitive and projects to areas in the central nervous system such as the dorsal motor nucleus of the vagus, ventrolateral medulla, and NTS known to be important areas in autonomic regulation of cardiovascular function. The purpose of this study was to test for the release of angiotensin peptides in the NTS after stimulation of AP. Coronal brainstem slices (300 um) containing both the AP and NTS were prepared from adult male Sprague – Dawley rats that were anesthetized with isoflurane (2–3%). The slices were perfused with oxygenated artificial cerebrospinal fluid (containing containing (in mM): 126 NaCl, 3.0 KCl, 2.0 CaCl2, 2.0 MgSO4, 1.25 NaH2PO4, 26 NaHCO3, 10 and D‐Glucose; 300 mOsm, pH 7.4). Sniffer cells were placed on the NTS and imaged on an Olympus B51WI equipped with epifluorescence using CellSens Dimensions software (Olympus). Sniffer cell images were captured once every second. Changes in fluorescent intensity of sniffer cells in the NTS was determined following electric stimulation of the AP (100Hz, 10ms, 1mA). Electrical stimulation increased fluorescence intensity 134 ± 11%, n=13 of sniffer cells on the NTS with a mean response latency of 4 ± 0.7sec, n=13. Some cells demonstrated spontaneous changes in fluorescence intensity 2±0.1, n=28 that were not observed in cells located outside of the NTS. The results indicate that sniffer cells placed on the NTS demonstrated evidence of spontaneous and evoked release of angiotensin peptides.

Support or Funding Information

P01 HL088052
PAWI‐2 Overcomes Tumor Stemness and Drug Resistance in Pancreatic Cancer Stem Cells
Authors: Cheng Jiongjia , Gomez-Galeno Jorge , Cashman John
Published: April 2020

Today, pancreatic cancer (PC) remains a major health problem in the US and soon will be the second most common cause of mortality due to cancer. However, most of the front‐line PC chemotherapies cause serious side effects and a majority of patients with PC are often resistant to clinical therapies. The fact that cancer stem cells (CSCs) become enriched after anti‐cancer therapy implicates CSCs as key contributors to tumor dormancy, metastasis, and relapse in PC. Given the important role of human pancreatic cancer stem cells (hPCSCs) in PC, development of a novel treatment strategy that targets hPCSCs or their extrinsic and intrinsic regulators could be of great clinical utility to treat PC. Herein, we used a highly validated hPCSCs model (FGβ3 cells) to test a novel compound (PAWI‐2) to target CSCs. In this hPCSC model, integrin αvβ3 expression was shown to be a marker/functional contributor to CSC progression and drug resistance attributed to its ability to trigger anchorage‐independent cell survival and tumor metastasis. Specifically, integrin αvβ3 recruits KRAS and RalB to tumor cell plasma membranes to activate NF‐κB signaling that triggers dysregulated KRAS‐RalB‐NF‐κB pathways. This was shown to be a pharmacological target to reverse CSC‐like properties or re‐sensitize drug resistance (e.g., EGFR inhibitors, erlotinib) of established FGβ3 tumors. Compared to parental FG cells, PAWI‐2 showed greater potency to inhibit cell viability and self‐renewal capacity of FGβ3 cells. PAWI‐2 inhibited dysregulated integrin β3‐KRAS‐RalB‐NF‐κB signaling independent of KRAS and Ral. This is clinically relevant because >90% of KRAS is activated by mutations in PC and RAS or Ral inhibitors have not proven effective clinically. PAWI‐2 targeted downstream of KRAS signaling and was negatively regulated by other feedback mechanisms. This was further shown by genetic knockdown of key regulator and co‐treatment of specific inhibitors. PAWI‐2 overcomes erlotinib resistance in FGβ3 cells with greater potency than bortezomib. In the proposed mechanism of PAWI‐2 action, key regulators link the inhibition of KRAS signaling and cell cycle arrest (G2/M). The great utility and pharmacological potency of PAWI‐2 in FGβ3 cells (that possess stem‐like properties) compared to FG cells provide a basis for further development. PAWI‐2 as an efficient therapeutic to reverse tumor stemness and resensitize CSC tumors to drug inhibition.

Support or Funding Information

This work was supported by Inception Award from California Institute for Regenerative Medicine (CIRM) (DISC1‐10583; J.R. Cashman) and by funds from the Human BioMolecular Research Institute.
Visualizing the Unbalanced World of Domestic Dogs: An Interactive Examination of the Canid Vestibular System
Authors: Smith Christopher M. , Tang Cheuk Y. , Laitman Jeffrey T.
Published: April 2020

The bony labyrinth (BL) of the petrous contains the organs responsible for balance (vestibular system) and hearing (cochlea). The vestibular system is comprised of three semicircular canals (which detect angular acceleration of the head) and two otolith organs (for detecting linear acceleration and static tilt). Studies in mammals have shown that semicircular canal morphology reflects sensitivity to angular acceleration, particularly canal orientations at right angles to one another (orthogonality). Due to their significant variation in craniofacial form while exhibiting similar locomotion, canids provide an excellent natural experiment to understand the influence of shape on vestibular morphology. This study expands upon our earlier analyses on relationships among BL size, cranial base length and semicircular canal morphology across dog breeds and creates an interactive three‐dimensional (3D) model of the canid cranium and BL to visualize relationships among variables. A portion of the sample is derived from the comprehensive study by Schweizer et al. on canid inner ear metrics (2017). Results show that orthogonality between the anterior and posterior semicircular canals is significantly correlated with BL size and cranial base length, suggesting their intimate association across dog breeds. Small, highly derived breeds, such as the short‐faced pug, had anterior and posterior semicircular canals that deviated the most from orthogonality. Similarly, due to their compressed cranial form, such highly bred domestic dogs may also be expected to exhibit altered vestibular function. Our interactive 3D model will allow visualization of statistically significant relationships among BL size, cranial base length and semicircular canal morphology among the breeds. The model will show predicted correlated change in the bony labyrinth based on cranial dimensions. In addition, the visualization will allow the prediction of intermediate and extreme semicircular canal morphologies by manipulating the dimensions of the model itself. By constructing such a model, we hope to lay the foundation for future research into visualizing the morphological integration of inner ear tissues and cranial architecture.

Support or Funding Information

This research was supported by The Graduate Center, City University of New York through a Graduate Center Fellowship; the New York Consortium in Evolutionary Primatology; and the Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai.
Sphingosine Kinase 1 Inhibitor, PF543, Blocks Inflammation and Airway Remodeling in a Murine Model of Allergic Asthma.
Authors: Ha Alison W. , Sudhadevi Tara , Ebenezer David L. , Fu Panfeng , Ackerman Steven J. , Natarajan Viswanathan , Harijith Anantha
Published: April 2020

Asthma, a heterogeneous airway inflammatory disease, affects more than 300 million people worldwide, presenting a significant health and economic burden. Structural changes in the lung, known as airway remodeling (AWRM), as well as inflammation and airway hyperresponsiveness characterize the complex pathophysiology of severe asthma. Sphinogosine‐1‐phosphate (S1P), a bioactive sphingolipid metabolite, formed by the phosphorylation of sphingosine by either sphingosine kinase 1 or 2 (SPHK1/SPHK2) was found to be elevated in the BAL of patients with asthma. S1P signaling is involved in the pathogenesis of several lung conditions, including asthma, however, its role in the progression of the disease remains unclear.

In our acute asthma model, sensitization of wild‐type C57BL/6 mice to Alum + a cocktail of allergens consisting of dust mite (D), Aspergillus (A), and ragweed (R), for 1 week, followed by challenge with DRA two weeks later, displayed an increase in inflammatory and eosinophil response, as well as goblet cell hyperplasia (Periodic acid‐Schiff staining) but no airway remodeling. In the chronic asthma model, mice were sensitized to DRA for 8 weeks, but no separate challenge was done. We observed increased pulmonary inflammation, in the absence of eosinophil response, as well as significant AWRM, as evidenced by increased subepithelial fibrosis (Masson’s trichrome staining) and smooth muscle hypertrophy (anti‐smooth muscle myosin heavy chain II staining). Furthermore, allergen challenged mice also showed increased airway hyper reactivity (AHR), as measured by methacholine challenge test. In the acute model, treatment with a specific SPHK1 inhibitor, PF543 (1 mg/kg), at 3 doses during allergen challenge, attenuated the inflammatory response, including eosinophil recruitment. In the chronic model, PF543 (1mg/kg) was administered twice weekly for three weeks after allergen challenge which reduced subepithelial fibrosis, and goblet cell hyperplasia. Decreased AHR was also observed following PF543 treatment. Together, these data suggest the significance of SPHK1/S1P signaling in the pathogenesis of asthma, as well as the therapeutic potential of PF543 in ameliorating inflammation and airway remodeling in allergic asthma.

Support or Funding Information

This work was supported by NIH/NICHD R01 HD090887 and AHA 18TPA34230095 to AH.
Human Carpal Evolution and its Implications for Hominin Locomotor Ancestry
Authors: Wuthrich Craig
Published: April 2020

The ancestral locomotor repertoire from which hominin bipedalism emerged remains a subject of frequent debate, with multiple competing hypotheses maintaining support among active researchers. This study contributes to this ongoing debate by reconstructing the morphological and locomotor evolution of hominoids based on patterns of morphometric variation in the capitate, hamate, lunate, and triquetrum among extant and fossil anthropoids, including humans and fossil hominins. Aspects of carpal morphology found to consistently covary with locomotor behavior are used to reconstruct adaptive transitions within the anthropoid clade associated with locomotor behavior. The prevalence of different locomotor behaviors at the origin of nested clades within Hominoidea, including the one we share with Pan, are also estimated.

While there is some inconsistency of morphological covariation with function and phylogeny among carpal elements, results are consistent in supporting frequent parallelism during hominoid locomotor evolution. This support is strongest as it applies to suspensory behaviors, with the last common ancestors of both apes and great apes predicted to have remained quite generalized relative to the clades’ extant representatives. The last common ancestor of humans and chimpanzees/bonobos is also estimated to have lacked adaptations in association with knuckle‐walking, providing further support for the hominin clade having descended from a relatively generalized ancestral morphotype that is not well modeled by any of the surviving hominoid lineages.
Optogenetic stimulation of Dbx1 neurons promote increase in sympathetic activity in vivo
Authors: Karlen-Amarante Marlusa , Huff Alyssa , Baertsch Nathan A , Colombari Debora S. A. , Ramirez Jan-Marino
Published: April 2020

Under resting conditions, breathing is characterized by inspiration and postinspiration. Located in the ventrolateral medulla, the preBötzinger Complex (pre‐BötC) is critical for generating the inspiratory phase of breathing. This microcircuit contains glutamatergic neurons derived from progenitor cells that are characterized by the transcription factor “developing brain homeobox (Dbx1)”, and that are thought to be important for inspiratory rhythmogenesis. Located rostromedial of the preBötC is the so called postinspiratory complex (PiCo), which seems to be critical for the generation of the postinspiratory phase of breathing. Important for generating the postinspiratory phase are glutamateric‐cholinergic PiCo neurons. At resting conditions, sympathetic and parasympathetic activity is modulated by excitatory and inhibitory synaptic inputs from these respiratory networks. It is thought that changes in the respiratory‐sympathetic coupling contribute to imbalances that lead to hypertension, as demonstrated in various animal models of chronic intermittent hypoxia. Here we combine optogenetic and electrophysiological approaches in vivo and in vitro in order to investigate the respiratory‐sympathetic coupling. Spontaneously breathing Dbx1‐ERT2Cre/Ai32 and ChAT‐Cre/Ai32 (ChR2) adult mice were anaesthetized (Urethane 1.5mg/kg), and the ventral surface of their brainstem exposed in order to place an optical fiber bilaterally over the pre‐BötC and/or PiCo, while recording the hypoglossal (HN), cervical vagus (cVN) and cervical sympathetic nerves (cSN). Our preliminary data indicate that continuous light stimulation (10s) of pre‐BötC Dbx1 neurons (~ 9mV, 447nm) significantly increased the respiratory frequency, the amplitude of HN, cSN and cVN in relation to baseline. During the optogenetic stimulation of Dbx1 neurons the respiratory‐sympathetic coupling was enhanced. Using the in vivo approach as well as in vitro horizontal slices we are currently also characterizing the role of PiCo in regulating this coupling under control conditions and following CIH. Our preliminary data suggest that PiCo activity is enhanced following CIH exposure, which also contributes to the regulation of respiratory‐sympathetic coupling. Unraveling how the respiratory microcircuits regulate autonomic control will be critical to understand how CIH leads to increased sympathetic drive and hypertension.

Support or Funding Information

FAPESP (2016/23513‐1; 2019/11969‐2), and the NIH: P01 HL090554, R01 HL144801 and R01 HL126523
Cannabinoid metabolites as potential inhibitors of major CYP450 enzymes. Implication for cannabis‐drug interactions.
Authors: Nasrin Shamema , Watson Christy J. , Chen Gang , Lazarus Philip
Published: April 2020

The recent legalization of marijuana in many parts of the United States and other countries has led to an increased need for a more comprehensive understanding of the metabolism of marijuana constituents, specifically in regard to potential drug‐drug interactions (DDIs) with cannabinoids and their numerous metabolites. To understand the DDI potential of cannabis, we are evaluating cannabis constituents and cannabinoid metabolites as possible inhibitors of phase I metabolizing enzymes. We hypothesize that inhibition of major drug metabolizing enzymes by cannabinoids metabolites [(−)‐trans‐Δ‐9‐ tetrahydrocannabinol (THC), 11‐hydroxy Δ9‐tetra hydrocannabinol(11‐OH‐THC), 11‐nor‐9‐carboxy‐Δ9‐tetrahydrocannbinol (THC‐COOH), THC‐COO‐glucuronide, cannabidiol (CBD) and cannabinol (CBN] can lead to an increase in hepatic and systemic exposure to certain drugs. In vitro assays demonstrated that THC, its major metabolites 11‐OH‐THC, THC‐COOH and THC‐COO‐glucuronide, CBD and CBN inhibit several major CYP enzymes. THC (IC50= 10 ± 4.7 μM), 11‐OH‐THC (IC50= 2.8 ± 1.4 μM), THC‐COO‐glucuronide (IC50= 7.6 ± 4.8 μM), and CBD (2.8 ± 1.2 μM) all inhibited the dextromethorphan‐O‐demethylase activity of recombinant CYP2D6. THC (IC50= 8.3 ± 3.2 μM), THC‐COO‐glucuronide (IC50= 7.2 ± 4.1 μM), CBD (IC50= 8.1 ± 4.3 μM) and CBN (IC50= 5.5 ± 3.1 μM) all inhibited the omeprazole‐5‐hydroxylase activity of recombinant CYP2C19, while 11‐OH‐THC (IC50= 5.02 ± 2.3 μM), THC‐COO‐glucuronide (IC50= 5.2 μM ± 3.5 μM), CBD (IC50= 0.8 ± 0.5 μM), and CBN (IC50= 1.5 ± 0.9 μM) all inhibited the bupropion hydroxylation activity of recombinant CYP2B6. In addition, CBD and CBN inhibited the chlorzoxazone‐6‐hydroxylase activity of recombinant CYP2E1 (IC50 were 0.9 μM ± 0.5 μM and 0.6 μM ± 0.4 μM, respectively). These data indicate that cannabinoids and their major metabolites are able to inhibit the activities of multiple CYP enzymes, suggesting a strong possibility for DDI with many exogenous compounds including a variety of drugs and carcinogens.

Support or Funding Information

This investigation was supported in part by funds provided by the State of Washington Initiative Measure No. 502