bluuebunny/crossref_metadata_2025_split huggingface dataset:
Four Weeks of Moderate Intensity Exercise on Levels of Cortisol, Antioxidant, and DNA Damage
Authors: Valdez Ruben , Medina Erika , Ponte Luis , Koh Yunsuk , Park Kyung‐Shin 
Published: June 2021

PURPOSEThis study investigated the effects of a 4‐week moderate intensity walking exercise on levels of cortisol, antioxidant status, and 8‐OXO‐guanosine in overweight or obese individuals.METHODS27 physically inactive, overweight or obese individuals were randomly assigned to either exercise (N=15) or control (N=12) group. The exercise group performed moderate intensity walking exercise on a treadmill for 60 minutes at 70% of HRmax for 4 weeks (3 days/week). Overnight fasting blood samples were collected before and after the study period to analyze levels of cortisol, antioxidant status, and 8‐OXO‐guanosine. Two‐way repeated measures ANOVA and Tukey post hoc tests were used for data analysis.RESULTSNo significant changes were found in both body weight and body composition among both groups following 4 week intervention. An increase in total antioxidant status (3.99±.15mM, Mean±SE → 4.33±.15, P=0.013) and decreases in levels of cortisol (2523.8±234.3pg/mL → 1890.7±196.2, P=.0016) and 8‐OXO‐guanosine (2078.7±138.8pg/mL → 1783.9±134.8, P=.0104) were found following 4 weeks of moderate intensity exercise; however, no significant difference were found in control group : total antioxidant status (3.99±.17 → 4.10±.17, P=.17), cortisol (2597.0±263.1 → 2482.6±219.3, P=.203), and 8‐OXO‐guanosine (1990.0±155.2 → 2021.4±150.8, P=.72).CONCLUSIONSThe 4‐week moderate intensity exercise resulted in no change in body mass; however, it reduced the level of stress hormone and DNA damage in blood and elevated total antioxidant protection. Results indicate that 4 weeks of moderate intensity exercise may induce positive changes in endocrine system independent from changes in body weight and body composition.
The Effect of Remote Ischemic Conditioning on Bubble Formation in a Decompression Sick Rat Model
Authors: Schmidt Nikolaj , Hansen Kasper , Pedersen Michael 
Published: June 2021

IntroductionDecompression sickness (DCS) is a disabling and potentially lethal condition where bubbles nucleate from supersaturated tissues during rapid decompression. These bubbles may obstruct end arteries and thereby induce ischemia and subsequent necrosis. Remote ischemic conditioning (rIC) has been proven to attenuate ischemia‐reperfusion injuries in the brain, heart, and after kidney transplantations.ObjectiveTo evaluate if rIC is associated with reduced damage in rats subjected to DCS.Method41 female Wistar rats were randomly assigned to rIC prior to (pre‐rIC; n=10) or after (per‐rIC; n=20) pressurization. A group of sham‐dive rats (n=11) was used as control. All groups were pressurized to 6 ATA (45 min) with subsequent decompression (0.5 ATA/min). rIC was performed with a custom made tourniquet strapped around one hind leg, accomplished by a series repeated 4 times: 5 min of ischemia followed by 5 min of reperfusion. DCS was evaluated with microultrasound imaging of the pulmonary artery for 2 hrs 20 min after decompression. Two days after the experimental procedure the brains were removed and histologically examined with 2,3,5‐triphenyltetrazolium chloride (TTC) to evaluate size of brain infarcted areas.ResultsMicroultrasound imaging showed no significant change in formation of nucleated bubbles in both pre‐ and per‐rIC treated groups compared to the control group. Similarly, TTC‐staining of the brain did not seem to indicate any differences between the groups.ConclusionThe lack of reduced bubble formation and brain damage in pre‐ or per‐rIC groups indicate that the rIC procedure was insufficient to treat DCS. Future studies are required to reveal the systemic response of rIC and its possible use in DCS treatment.
Impact of ATP1B4 Gene Co‐option on Perinatal Development of Placental Mammals
Authors: Modyanov Nikolai , de la Serna Ivana , Ahmad Nisar , Russo Lucia , Pestov Nikolay , Najjar Sonia 
Published: June 2021

Vertebrate X‐chromosome ATP1B4 genes represent a rare instance of orthologous gene co‐option that transformed Na,K‐ATPase BetaM subunit of lower vertebrates into eutherian skeletal and cardiac muscle‐specific BetaM protein of the inner nuclear membrane. BetaM is expressed at the highest level during late fetal and early postnatal development and is implicated in the regulation of gene expression. We show that BetaM is a component of MyoD, MyoG and Smad7 transcriptional complexes in neonatal skeletal muscle and up‐regulates MyoD expression in cultured muscle cells by altering chromatin structure and recruiting SWI/SNF to the MyoD promoter.Notably, Atp1b4 ablation in mice results in significantly lower body weight, growth retardation and high mortality of knockout neonates. Moreover,mRNA sequencing of skeletal muscle from neonatal WT and KO male littermates revealed broad changes in expression of genes important for lipid metabolism and thermoregulation as well as down regulation of fast‐twitch and up‐regulation of slow‐twitch muscle genes. These data indicate that BetaM plays an important role during a critical period of perinatal and neonatal development of placental mammals and that evolutionarily acquired new functions of BetaM proteins are physiologically essential, even might be necessary for survival of placental mammals in natural conditions, and provide an evolutionary advantage.Supported by Dept. of Physiology & Pharmacology and Center for Diabetes and Endocrine Research, UT COM
Transition Journey: Conventional Teaching to Integrated Teaching in Third World Countries
Authors: Potaliya Pushpa , Ghatak Surjit 
Published: June 2021

IntroductionMost of third world countries have started moving on from non‐integrated discipline based system where major focus is on didactic lectures, tutorials and subjective assessment with very less emphasis on interactions. To have better diagnostic abilities among medical students the ideal approach is the integration of basic preclinical subjects along with developing an understanding of correlating them with clinical cases.Objective1. To compare and evaluate integrated teaching with traditional education system.2. To observe its effects on performance of students by an experiment model.3. To evaluate how it can improve quality of medical education in developing countries.Material and MethodTarget learners were divided in two Groups A and B to undergo traditional Conventional and Integrated teaching respectively for a particular topic. Earlier whole lot was undergoing same conventional method for various topics. Pre and post session questionnaires were given to students. Faculty feedback was also considered and noted. Statistical analysis was done for obtained data.ResultBoth short and long term outcome of implementing such module will be discussed at time of conference. Along with that discussion would emphasize on its role in the medical education system of developing countries and difficulties encountered to implement it there.ConclusionBy executing integrated system, a tremendous responsibility of the institutions to provide quality care to people can be achieved with ease and for long term in present scenario. This will definitely be a boon to the healthcare sector of third world countries.
Changing the course: Evaluation of a Novel Pedagogical Approach to Clinical Musculoskeletal Anatomy Education
Authors: Rascoe Alexander , Anderson Daniel , Black, MD Kevin , Lazarus, PhD Michelle 
Published: June 2021

Musculoskeletal (MSK) complaints, including back pain, represent a large percentage of physician office visits. Despite the disease burden, current literature suggests physicians are not adequately trained to care for these conditions. Enabling future providers to address MSK complaints requires revising the current medical school curriculum.Here we report a novel curriculum developed through the application of contextual learning theory and a targeted needs assessment. The course emphasizes clinical reasoning in the primary care setting and intra‐specialist communication through application of a “multi‐disciplinary” teaching approach. Throughout the course, students dissect cadavers, practice clinical reasoning skills and discuss surgical treatment options. Course participants improved by an average of 24% (p<0.05) on a validated MSK clinical anatomy free‐response examination; while a control group showed no change. Pilot data suggests this pedagogical approach results in a significant 6 month retention of the clinically applicable anatomy above that obtained by historical peers. This study demonstrates that vertical integration of basic science into clinical year medicine is an effective method for quantifiable knowledge improvement and retention. Moreover, the course design and implementation may serve as a blueprint for further vertical integration of basic sciences into clinical year medical education.
Impact of Clinical Anatomy League of University of São Paulo Medical School (FMUSP) on motivation and performance of anatomy learning
Authors: Iuamoto Leandro , Nogueira Thiago , Souza Braian , Ribeiro João , Hojaij Flávio , Akamatsu Flávia , Andrade Mauro , Jacomo Alfredo 
Published: June 2021

Undergraduate medical students learn anatomy basically by textbooks, lectures and cadavers dissection. The Clinical Anatomy League of University of São Paulo Medical School (CAL‐FMUSP) is an initiative to strengthen the anatomy learning and to complement the knowledge acquired during graduation.To describe the activities of the CAL‐FMUSP and analyze its impact on student's interest, motivation and learning.Questionnaires were answered by the League's introductory course attending students (n=53). In a second moment (2014), a 20‐question exam was applied to assess students' ability to identify and describe important anatomical structures. 33 students agreed to take the exam. Fourteen (42.4%) were League members – intervention group – and 19 (57.6%) composed the control group. Also we compared student's baseline grades Anatomy Course.Students' motivations in becoming a League member were: improve their anatomical knowledge (34.6%) and be able to understand the anatomy involved on surgical procedures (21.0%). The expectations on League's activities were: improve surgical technique and dissection on fresh cadavers such as fixate their knowledge (26.7%). Students' moderate interests on the League went from 29.4% to 14.0%, intense interest raised from 49.0% to 54% and very intense interest increased from 21.6% to 32.0%. In the exam‐based experiment, League members' performance on the exam was better in comparison to the control group performance (p = 0.044).The CAL‐FMUSP with its course and activities stimulates medicine students' interest in anatomy and improves the anatomical knowledge fixation.
Identifying Mechanisms and Evolutionary Implications of Mechanosensitive Growth in the Embryonic Limb Skeleton
Authors: Pollard Andrea , Charlton Bethany , McGonnell Imelda , Pitsillides Andrew 
Published: June 2021

The developing skeleton experiences loading as a result of embryo movement. This is necessary for normal longitudinal growth of limb skeletal elements. Herein, we address the hypothesis that mechanical input can alter limb proportions by modifying growth.We aimed to identify mechanisms which underpin altered growth in response to mechanical input and demonstrate that environmental factors such as incubation temperature can alter motility in oviparous species, altering limb proportions.Embryonic chicks were immobilised with a neuromuscular blocker between day 10‐18 of development and growth monitored by repeat MRI scans. Control embryos were treated with vehicle only. Crocodile eggs were incubated at 28°C and 32°C and movement monitored throughout development. Embryos were euthanized at near‐hatching age and body size and limb proportions measured. Proliferation, hypertrophy and apoptosis, components of endochondral ossification, were evaluated in limb growth cartilage of all groups.Growth was reduced by immobilisation predominantly in the metatarsals and femur in chicks. The distribution of proliferation was altered, volume of hypertrophic chondrocytes decreased (29% P<0.05) and apoptosis increased in these elements, suggesting that mechanical input is necessary to direct and regulate these processes. Temperature influences motility of embryonic crocodiles and alters limb proportion, with greater temperatures producing longer tibias and shorter digits. This may explain the variation in limb proportionality observed within some reptile species and our data suggest that plasticity in limb form during development may be evolutionarily advantageous.This work is funded by the Anatomical Society.
Protective role of phosphatidic acid in the cellular response to lysophosphatidylcholine analogues
Authors: Ganesan Suriakarthiga , Fernandez Murray Pedro , McMaster Christopher , Zaremberg Vanina 
Published: June 2021

The synthetic lysophosphatidylcholine (LPC) analogue edelfosine and the naturally occurring platelet activating factor (PAF) are structurally related lipids. Edelfosine is a potent antitumor drug, while PAF is a neurotoxic lipid that has been implicated in Alzheimer's disease. These LPC analogues are also toxic to budding yeast, which can be used as an excellent model system to investigate their mode of action.LPC analogues induce alterations in membrane organization, lipid metabolism and signaling in yeast. Phosphatidic acid (PA) produced by the activity of PLD alleviates sensitivity of yeast cells to PAF and edelfosine. PA is a key lipid signalling and precursor of all glycerolipids. Recent lipid analysis indicates that diacylglycerol (DAG) accumulates in cells treated with LPC analogues and this could contribute to their toxicity. In fact, sensitivity assays in yeast genetically manipulated to alter PA and DAG levels clearly support a protective role of PA in the response to these lipid drugs. Altogether, the evidence suggests that cells are able to sense altered PA: DAG ratios induced by these metabolically stable lipids. While DAG binding proteins have not been clearly identified in yeast, several yeast proteins recognize PA with high specificity. One such protein is the transcriptional repressor Opi1, which regulates expression of phospholipid biosynthetic genes through its interaction with PA. We provide evidence supporting a role of Opi1 in sensing the membrane changes induced by edelfosine, including i) altered sensitivity of cells lacking Opi1, ii) prevalent nuclear localization and iii) Opi1‐dependent UASINO gene repression induced by edelfosine.
Targeting the SUMO E1‐E2 Enzyme Interaction in Plasmodium falciparum
Authors: Reiter Katherine , Bosch Jurgen , Matunis Michael 
Published: June 2021

Resistance to first‐line anti‐malarial drugs has accelerated the need for new drugs with novel targets for effective malaria treatment. Many of the current anti‐malarial drugs work in part by overwhelming the parasite stress response. In eukaryotes, the oxidative stress response machinery includes antioxidants as well as SUMOylation, a post‐translational modification that involves the covalent attachment of small ubiquitin‐related modifiers (SUMOs) to proteins. We hypothesize that SUMOylation plays an essential role in parasite cell stress survival, and that parasite‐specific SUMOylation inhibitors could prove effective in combination with current anti‐malarial drugs. We have previously demonstrated that human and Plasmodium falciparum (Pf) SUMO conjugation systems have biochemically distinct E1‐E2 enzyme interactions, suggesting a target for drug development. Here, we use x‐ray crystallographic studies to further define and compare the human and Pf E1‐E2 interaction. We have identified non‐conserved and structurally distinct surface residues that will help guide the identification of parasite‐specific inhibitors of SUMOylation.This research was funded in part by the National Institutes of Health (GM060980), the Johns Hopkins School of Public Health Sommer Scholar's Program, and the Johns Hopkins Malaria Research Institute.
Three‐dimensional Collagen IV and Hormone Prolactin Regulate Breast Cancer Cell Invasion: Role of PAK1 and Matrix Metalloproteinases
Authors: Diakonova Maria , Oladimeji Peter , Rider Leah 
Published: June 2021

Three‐dimensional (3D) matrix is a critical component of mammary tissue development not only under physiological but also in pathophysiological conditions. The hormone/cytokine prolactin (PRL) also contributes to the pathogenesis of breast cancer via activation of JAK2/ STAT‐ and MAPK‐dependent pathways. Serine‐threonine kinase PAK1 is one of the targets of PRL‐activated JAK2. We showed previously that tyrosine kinase JAK2 phosphorylates PAK1 in response to PRL on three tyrosines (Tyr 153, 201 and 285). We show herein that the PAK1 phosphorylation is required for maximal PRL‐dependent invasion of human breast cancer cells through Matrigel and that 3D collagen IV acts synergistically with PRL‐activated PAK1 to induce the expression and secretion of MMP‐1 and MMP‐3. In contrast, PRL‐activated PAK1 decreases the 3D collagen IV induction of MMP‐2. MMP‐9 expression and secretion are stimulated by 3D collagen I, not collagen IV, and are not affected by PRL but are down‐regulated by PAK1. Using shRNA or pharmacological inhibitors, we show that MMP‐1 and ‐3 are required and MMP‐2 contributes to PRL‐ dependent invasion. Erk 1/2 signaling appears to be required for the enhanced expression and secretion of MMP‐1, and ‐3 and enhanced PRL‐dependent invasion. p38 MAPK and JNK 1/2 pathways participate in production of MMP‐1 and ‐3 as well as in PRL/PAK1‐dpendent cell invasion. The NFkB pathway is required for MMP‐3 and ‐9 secretion. Together, these data illustrate complex interaction between cellular substrate and PRL regulation of breast cancer cell progression, implicating a pivotal role for PAK1 tyrosyl phosphorylation in MMP regulation.This work was supported by National Institutes of Health Grant R01 DK88127 (to MD).
The Role of Complement and the Extracellular Matrix in Early Stage Macular Degeneration
Authors: Fernandez‐Godino Rosario , Pierce Eric , Garland Donita 
Published: June 2021

Gene targeted Efemp1R345W/R345W knockin mice are a documented model of the Efemp1‐associated macular degeneration. These mice develop features of macular degenerations including extensive basal deposits when the complement system is active. The aim of this project was to use cultured primary RPE cells to study the mechanisms involved in the pathogenesis of basal deposit formation and the role of the complement system.Mice were used in conformance with the FASEB Statement of Principles for the use of animals in research and education. Primary RPE cells from wild type, Efemp1R345W/R345W, and Efemp1R345W/R345W:C3‐/‐mice were grown on transwells. Cell phenotypes were characterized by electron microscopy. The presence of complement components and factors, extracellular matrix proteins and pro‐inflammatory molecules were quantified by qRT‐PCR, immunofluorescence and ELISA. The activities of specific proteins were modulated with antibodies and recombinant proteins.We conclude that cultured primary RPE cells from Efemp1R345W/R345W knockin but not from wild type or double mutant Efemp1R345W/R345W:C3‐/‐mice form extracellular deposits. The deposits contain extracellular matrix and complement proteins. The formation of deposits can be inhibited by neutralizing C3a, IL‐1B, IL‐6 or EFEMP1 in Efemp1R345W/R345W cultures. Wild type cells make deposits in the presence of C3a or recombinant mutant EFEMP1.We conclude that RPE cells from Efemp1R345W/R345W knockin mice generate the extracellular deposits through a C3a dependent mechanism that is activated by EFEMP1R345W. These cells thus provide a model system to investigate the early mechanisms responsible for RPE dysfunction in macular degeneration.
Exploiting Non‐Canonical Amino Acids to Alter Enzyme Substrate Specificity
Authors: Windle Claire , Nelson Adam , Pearson Arwen , Berry Alan 
Published: June 2021

Enzymes are constructed from the 20 proteogenic amino acids, but Nature has expanded the chemistries available in proteins by recruiting cofactors or inserting non‐canonical amino acids (ncAAs). Until recently, protein engineering was restricted to using the 20 proteogenic amino acids. Using a chemical method, we are able to produce proteins containing ncAAs quickly and in high yields. This method works by first converting a cysteine into a dehydroalanine intermediate, before reacting with a thiol to produce the non‐canonical side chain. Initial studies focussed on replacing the catalytic lysine in the aldolase N‐acetyl‐neuraminic acid lyase (NAL) with a γ‐thialysine, this enzyme has been characterised both kinetically and crystallographically.Using this methodology, we have explored the effect of an increased amino acid repertoire on enzyme substrate specificity by inserting multiple ncAAs (~16) at various positions (~11) throughout the active site of NAL, and screening for altered activity. This has produced an ncAA‐containing aldolase with a 10 fold increased kcat, with a shortened substrate, over that of the wild‐type. Saturation mutagenesis has also revealed that this increase in activity is not achievable with any of the proteogenic amino acids. Crystallographic and computational studies have been used to elucidate the mechanism by which this ncAA increases activity.This work highlights that activities previously thought inaccessible by use of the 20 proteogenic amino acids may now be achievable by use of ncAAs.
Characterization of a Small‐molecule Modulator of IRE1α Activity
Authors: Salami‐Oyenuga Jemilat , Raina Kanak , Crews Craig 
Published: June 2021

Endoplasmic Reticulum (ER) stress due to the accumulation of unfolded/misfolded proteins in the ER lumen is resolved by a series of cellular processes, known collectively as the Unfolded Protein Response (UPR). UPR signaling is responsible for maintaining cell health under ER stress conditions and its misregulation has been implicated in the pathogenesis of several diseases. To remediate misregulated UPR, new ways to probe/modulate UPR signaling have to be developed. Along these lines, our lab has synthesized a novel small molecule (NA14) that interacts with and modulates the downstream activity of Inositol Requiring Enzyme 1 (IRE1α), a central player in one of the three signaling branches responsible for ER stress response. We have characterized the interaction between NA14 and recombinant human IRE1α protein using thermal shift assays and studied its effects on IRE1α kinase and ribonuclease enzymatic activities. We have also tested the toxicity of NA14 to HEK293T human kidney cells and treated these cells with NA14 to study its effects on downstream IRE1α and UPR signaling.We show that NA14 binds to recombinant human IRE1α and also inhibits its kinase and ribonuclease enzymatic activities. We also show that NA14 is not cytotoxic to HEK293T cells. We are currently working on understanding the effects of NA14 on downstream human IRE1α and UPR signaling. Till date, we have used a luciferase reporter assay to show that NA14 downregulates the splicing of X‐Box Binding Protein 1 (XBP1) mRNA, one of the key consequence of IRE1α activation.Our aim is to have a clear understanding of the mechanism of regulation of IRE1α activity by NA14. This would enable its use as a chemical probe for studying ER stress pathways in normal and disease contexts.