bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative efficacy of group versus individual feedback regarding medical student professionalism in gross anatomy
Authors: Camp Christopher Lee , Gregory Jeremy K , Chen Laura P , Alexander Cara J , Jacobs Sarah M , Lachman Nirusha , Pawlina Wojciech 
Published: June 2021

Professionalism is a core competency of gross anatomy and general medical school curricula requiring students to develop the skills of giving and receiving peer feedback. Our study evaluated the effectiveness of delivering feedback in a group setting compared to delivering it individually. The first year class of Mayo medical students (n=50) enrolled in gross anatomy (in dissection teams of 3 or 4) completed weekly anonymous peer‐evaluations of their team regarding multiple aspects of professionalism (integrity, responsibility, compassion, and peer respect). Professionalism scores were calculated using the quantitative values from these surveys. Students were also asked to comment on strengths and areas for improvement for each student. At the mid‐point of the course, peer comments and professionalism scores were shared with students in debriefing sessions, either individually or as a team. Preliminary analysis of pre‐ and post‐intervention professionalism scores indicates that students receiving feedback in a group setting are more likely to demonstrate higher scores on subsequent evaluations. Our findings suggest that providing feedback to first‐year medical students in a group setting is more beneficial for group dynamics and may improve professional attitudes and behaviors. This work was supported by the Mayo Clinic Department of Anatomy.Grant Funding SourceNone
A slow ATP‐induced conformational change limits the rate of DNA binding but not the rate of β clamp binding by the Escherichia coli γ‐complex clamp loader
Authors: Thompson Jennifer Ann , Paschall Christopher O , Bloom Linda B 
Published: June 2021

In the E. coli DNA replication system, the five‐subunit clamp loader, γ‐complex, loads the βsliding clamp onto DNA. The βclamp, a ring shaped dimer of identical subunits, tethers DNA polymerase III to DNA and enhances the efficiency of replication by increasing the processivity of DNA synthesis. In the presence of ATP, γ‐complex binds to βand DNA to form a ternary complex. Binding to primed template DNA triggers the clamp loader to hydrolyze ATP. Upon ATP hydrolysis, βis released onto DNA and γ‐complex dissociates from the complex. We have developed a βbinding fluorescence assay by covalently attaching a fluorophore, pyrene, onto a Cys residue (Q299C) ofβ. The fluorescence increases two‐fold when γ‐ complex binds β‐pyrene. Using this assay, the rates of association, kon of 3.5 x 107 M−1s−1 and dissociation, koff of 0.005 s−1 of γ‐complex binding to βwere determined in real time. In addition, the kinetics of γ‐ complex binding to DNA were measured in real time to compare to those for βbinding. When γ‐complex is pre‐incubated with ATP, the clamp loader can bind βor DNA with no preferred order. When there is no ATP pre‐incubation, γ‐complex must undergo a slow ATP‐induced conformational change before binding to DNA but does not have to undergo this change when binding toβ. Thus, there may be a kinetic preference for γ‐complex to bind βbefore DNA during the clamp loading reaction cycle.This work was supported by NIH grant GM055596.
Antiproliferative Effects of Novel Glycosylated 24‐kDa Human Growth Hormone on MCF‐7 Breast Cancer Cells
Authors: Haro Luis S. , Haro Elizabeth K. , Muñoz Jesus , Martinez Andrew O. 
Published: June 2021

Human growth hormone (hGH) has been correlated with increased incidence of breast cancer, pointing to a need for development of hGH antagonists to block hGH‐dependent breast cancers. The objective of this research was to investigate the new untested concept that glycosylated 24‐kDa‐hGH would impede proliferation of human breast cancer cells. The hypothesis tested was that glycosylated 24‐kDa‐hGH would produce growth‐inhibitory effects in MCF‐7 human breast cancer cells.MethodsTo test this hypothesis, the number of viable breast cancer cells were quantified following a 72 hr incubation in nutrient‐rich media at 37 °C, in a humidified atmosphere of 95% air, 5% CO2, in the absence of GHs (vehicle control) or in the presence of either 22‐kDa hGH or glycosylated 24‐kDa‐hGH. One‐Way ANOVA followed by Student‐Neuman‐Keuls post‐hoc test assessed differences in breast cancer cell proliferation among the treatments. Results demonstrated that glycosylated 24‐kDa‐hGH significantly decreased the growth of human breast cancer cells compared to the 22‐kDa hGH and to the control group whereas 22‐kDa hGH stimulated their proliferation. Glycosylated 24‐kDa‐hGH acted as an antagonist of 22‐kDa hGH. The importance of this work is that it demonstrates that glycosylated 24‐kDa‐hGH possesses therapeutic potential as an anti‐neoplastic agent for combating human breast cancer growth in vivo.
INVESTIGATING THE ROLE OF RORγT IN HUMAN TH17 CELLS
Authors: John Tamika Leola , Manel Nicolas , Littman Dan 
Published: June 2021

CD4+ Helper T‐cells aid in coordinating the immune response by activating and directing other immune cells. For the past two decades, it has been thought that there are only two major subsets of differentiated helper T‐cells: Th1 and Th2 cells. However, a new subset of helper T‐cells was discovered recently. This new subset has been termed Th17 cells because its hallmark secreted cytokine is interleukin‐17. Previous research has shown a positive correlation between high levels of Th17 cells and incidence of auto‐immune diseases. Given Th17 cells' involvement in autoimmunity, the requirements for Th17 differentiation have come under investigation. It has been reported that the protein RORγT, a transcription factor, is required for the differentiation of Th17 cells in mice. The aim of this project was to assess whether RORγT is necessary for the differentiation of Th17 cells in humans. Short‐hairpin RNAs were used to attempt the silencing of RORγT in human T‐cells to determine its role in the production of interleukin‐17. Results suggest that RORγT is involved in human Th17 cell differentiation.This investigation was supported, in part, by UMBC through the NIH NRSA Award GM 08663 to the MARC U*STAR Program at UMBC and by the HHMI Undergraduate Scholars Program at the University of Maryland, Baltimore County (UMBC) and the Howard Hughes Medical Institute.
Spontaneously Hypertensive Rat (SHR) Display Alterations in Carbohydrate Metabolism And Function At An Early Age
Authors: Lauzier Benjamin , Labarthe Francois , Bouchard Bertrand , McDuff Janie , Gélinas Roselle , Foisy Sylvain , Charron Guy , Des Rosiers Christine 
Published: June 2021

The SHR, a genetic model of hypertension with a CD36 gene defect, develops left ventricular hypertrophy (LVH) between 9 and 12 weeks of age. We reported that 15‐wk‐old SHR display a reduced exogenous fatty acid (FA) oxidation, while that of carbohydrate (CHO) was unchanged despite an enhanced glycolysis. This study aimed at clarifying whether these alterations are characteristic of this rat strain or result from metabolic gene remodeling linked to LVH. We assessed the metabolic and functional profile of working hearts perfused with 13C‐labeled substrates at 7 weeks (SHR vs Wistar), and cardiac metabolic gene expression by qPCR at 7 and 15 weeks. As young Wistar hearts were not able to maintain stable cardiac output at 80 mmHg, they were perfused at 70 mmHg afterload to match functions with SHR. At the metabolic level, SHR hearts displayed a 40% lower FA β‐oxidation, while CHO oxidation was increased by 50% (p<0.05). qPCR data revealed that SHR hearts showed marginal differences in mRNA levels for genes involved in FA and CHO metabolism at 7 weeks, but a significant increase in all these gene transcripts at 15 weeks. Compared to their 15‐week‐old counterpart, young SHR hearts displayed a similar lower FA oxidation, but an increase in CHO oxidation. The latter difference appears to be explained by transcriptional changes in PDK4 linked to LVH, and may confer to young SHR hearts the capacity to withstand a higher workload.(Supported by the Fondation Bettencourt Schueller and CIHR).
Characterization of essential fatty acid metabolism using the stable isotope tracer technique and gas chromatography/ mass spectrometric assay
Authors: Lin Yu Hong , Song Byoung‐Joon , Llanos Adolfo R , Lefkowitz William , Uauy Ricardo , Salem Norman 
Published: June 2021

To better understand essential fatty acid metabolism, several in vivo and in vitro studies have been performed. Diet controlled rats were orally administrated a mixture of two or more labeled fatty acids: d5‐linoleate, ‐linolenate, ‐dihomo‐gamma‐linolenate (DGLA), and/or 13C‐U‐ linoleate or eicosapentaenoate. GC/MS NCI assay was employed to measure the isotopic precursors, their respective metabolites in rat organs over a time‐course from 4 h up to 25 d. Results and conclusions. 1. Only 2.6% and 6% of linoleate and linolenate, respectively, were elongated and desaturated in rats with about 78% being utilized for beta‐oxidation, excretion, or other loss and 16~18% was stored in tissues, mainly adipose, as the precursor itself. 2. Eicosapentaenoate was a more efficient substrate for docosahexaenoate (DHA) than linolenate; similarly, DGLA is a better substrate for arachidonate and n‐6 docosapentanoate than was linoleate. 3. Dietary DHA is the primary source of brain DHA. 4. Preformed DHA markedly decreased the accumulation of de novo biosynthesized DHA and n‐6 docosapentaenoate in liver, plasma, heart and brain; but no significant differences in rat hepatocytes delta‐5 or ‐6 desaturase activities have been observed. Decreased accumulation of newly‐synthesized DHA by dietary DHA may relate to increased DHA catabolism.This project was funded by the DICBR, NIAAA, NIH.
Effects of high fat diet on multiple indices of oxidative stress in the brain
Authors: Liu Ying , Zhang Le , Fernandez‐Kim Sun OK , Morrison Christopher , Bruce‐Keller Annadora , Keller Jeffrey N. 
Published: June 2021

Consumption of a high fat diet is known to have deleterious effects on multiple organ systems, although the effects of high fat diet consumption on the brain remains poorly defined. Oxidative stress is believed to contribute to the aging of multiple tissues, including the brain, although currently it remains unclear whether consumption of a high fat diet is capable of altering age‐related changes in oxidative stress within the brain. In the present study we report on the effects of high fat diet consumption on multiple indices of oxidative stress in the brain including the levels of protein carbonyls, HNE‐modified proteins, nitrosylated proteins, and glycated proteins. In addition we report on the effects of a high fat diet on the expression of nuclear factor erythroid 2‐related factor 2 (Nrf2), which is a critical regulator of antioxidant enzymes in the brain. Additionally, we report on the ability of aging to modulate the effects of high fat diet consumption on the brain. Taken together, these data have important implications for understanding how diet may alter the development of oxidative stress and aging within the brain.Supported by grants from the Chinese Ministry of Education, the Chinese Scholarship Council, National Institute of Aging, and the Hibernia National Bank/Edward G. Schlieder Chair
Changed expression profile of complement regulatory proteins (Cregs) on leukocytes after severe injury in humans
Authors: Amara Umme , Kalbitz Miriam , Acker Barbara , Perl Mario , Weiss Manfred , Huber‐Lang Markus 
Published: June 2021

IntroductionComplement as crucial element of the innate immune system becomes uncontrolled and excessively activated after severe injury and sepsis. However, protection against complement‐mediated tissue destruction is provided by a variety of soluble and membrane‐bound complement regulatory proteins (Cregs). So far, the cellular expression profile of the Cregs in patients with the multiple injuries is not clear.Material and MethodsThe expression profiles of the most relevant Cregs on leukocytes (neutrophils, monocytes and lymphocytes) were investigated using flow cytometric analysis obtained from either age‐ and sex‐matched healthy volunteers (n=16) or polytraumatized patients (n=12; injury severity score ISS =18) at admission in the emergency room and 4, 12, 24, 120 and 240 h after trauma.ResultsIn current study the expression profiles of Cregs on leukocytes were found to be significantly altered, reflected by specific changes in CD35 (complement receptor 1, CR1), CD46 (membrane co‐factor protein, MCP), CD55 (decay accelerating factor, DAF) and CD59 (MAC inhibitor). Some of them demonstrated a cell type‐dependent (neutrophils, monocytes and lymphocytes) different expression pattern, whereas some of them exhibited a comparable cellular expression profile during the trauma course, indicating different regulation pathways. Furthermore, CD59 and CD46 neutrophil expression correlated with injury severity.ConclusionThe data suggest that Cregs expression profiles on leukocytes from polytraumatized humans are specifically changed after trauma, indicative of a trauma‐induced "complementopathy".
Inhibition of cellular lipid biosynthesis by sulfated oxysterol is mediated via the LXR pathway
Authors: MA YONGJIE , Xu Leyuan , Pandak William M , Hylemon Phillip , Ren Shunlin 
Published: June 2021

Nuclear oxysterol receptor, Liver X receptor (LXR) is a key transcriptional regulator of liver lipid metabolism. We recently identified the oxysterol 25‐diol 3‐sulfate (25HC3S) as an important regulatory molecule in liver. We now have studied the effects of 25HC3S and its precursor, 25‐hydroxycholesterol (25HC) on the LXR/SREBP‐1 signaling pathway in microphages. Addition of 25HC3S to human macrophages markedly decreased nuclear LXR protein levels. Real time PCR and western blot results showed 25HC3S inhibited SREBP‐1 mRNA and protein mature form.25HC3S decreased the expression of SREBP‐1‐responsive genes including acetyl CoA carboxylase‐1 and fatty acid synthase, as well as HMGR and LDLR, which are key proteins involved in lipids metabolism.Subsequently, Oil‐Red O staining and TLC found 25HC3S inhibited intracellular lipids accumulation.25HC as a LXR ligand had opposite effects, increasing ABCA1, ABCG1, SREBP‐1, and FAS mRNA levels in the macrophages. In the presence of 25HC3S, 25HC and LXR agonist T0901317 failed to increase LXR targeting gene expression. We conclude that 25HC3S acts in macrophage as cholesterol satiety signal, down‐regulating cholesterol and fatty acid biosynthetic pathways via inhibition of LXR/SREBP signaling. These studies suggest that 25HC3S is a potent regulator of lipid metabolism in macrophages.
Transgenic Overexpression of AlphaBeta1 Integrin Stimulates p70S6K Phosphorylation in Mice with a Severe Form of Muscular Dystrophy
Authors: Boppart Marni Della , Kaufman Stephen J 
Published: June 2021

MCK‐driven transgenic expression of the alpha7 integrin can ameliorate pathology in a mouse model of Duchenne muscular dystrophy (mdx/utrn‐/‐) and thus compensate for the loss of dystrophin in diseased mice. In spite of the beneficial effects of the alpha7 integrin in protecting mice from dystrophy, identification of molecular signaling events responsible for these changes remain to be established.PURPOSETo determine a role for signaling in the amelioration of muscular dystrophy by alpha7 integrin.METHODSFive wk wild type, mdx/utrn‐/‐, and alpha7BX2‐mdx/utrn‐/‐ gastrocnemius muscles (n=3‐8/group) were dissected and extracted. Activation of PI3K, ILK, AKT, mTOR, p70S6K, GSK‐3, and p38 was measured using in vitro activity assays or phosphospecific antibodies and western blotting.RESULTSSignificant increases in ILK activity (2.0‐fold), AKT‐(P) (2.3‐fold), mTOR‐(P) (57%), p70S6K‐(P) (11.7‐fold), and ERK‐(P) (66%) were observed in dystrophic mdx/utrn‐/‐ muscle compared to wild type. Significant decreases in GSK‐3‐(P) (57%) and p38‐(P)(2.9‐fold) were also observed. Most of these signaling events were similar in dystrophic mice over‐expressing the alpha7 integrin. However, a further increase in p70S6K‐(P) (18‐fold) and decrease in GSK‐3‐(P)(3.7‐fold) were detected in alpha7BX2‐mdx/utrn‐/‐ compared to wild type mice and these changes were significant compared to mdx/utrn‐/‐ mice.CONCLUSIONThe alpha7beta1 integrin confers a protective effect in dystrophic mice and increased p70S6K activity appears important to this. Supported by the NIH and MDA.
Inflammatory stress and incipient apoptosis in primary venous and aortic endothelial cells (ECs) of type 1 diabetic mice
Authors: Bucciarelli Loredana G. , Pollreisz Andreas , Kebschull Moritz , Ganda Anjali , Kalea Anastasia Z. , Hudson Barry I. , Zou Yu Shan , Lalla Evanthia , Ramasamy Ravichandran , Colombo Paolo C. , Schmidt Ann Marie , Yan Shi Fang 
Published: June 2021

The progression of diabetic vasculopathy is associated with profound endothelial dysfunction. We tested the hypothesis that markers of cellular stress would be detectable in ECs retrieved from both arteries and veins of type 1 diabetic mice.We directly isolated aortic and venous ECs from type 1 diabetic mice (streptozotocin) and age‐matched C57BL/6 controls. EC purity was supported by comparing levels of smooth muscle and leukocyte markers (amplified mRNA) between whole aorta (present) and aortic ECs (negligible).Gene expression profiling was performed using Mouse Endothelial Cell Biology RT² Profiler(tm) PCR Array and confirmed by real‐time PCR. At 18 weeks of age, Interleukin‐1b was 80x higher in aortic ECs and 15x higher in venous ECs of diabetic mice vs. controls (p=0.03, p=0.01, respectively). At 36 weeks of age, Caspase‐1 was 369x higher in aortic ECs and 618x higher in venous ECs of diabetic mice vs. controls (p=0.04, p<0.05, respectively). By western blot, trends towards higher levels of Cleaved Caspase‐3 protein were seen in aortic and venous ECs retrieved from diabetic mice vs. control mice (p=0.05).Given new minimally‐invasive techniques to harvest human venous ECs to track disease activity and gauge response to treatment, these results are clinically relevant to studies of human subjects with diabetes.Funded by United States Public Health Service hl60901 and JDRF.
Neuroprotectin D1 Modulates Bcl‐xL Phosphorylation during Oxidative Stress in Retinal Pigment Epithelial Cells
Authors: Antony Rajee , Bazan Nicolas 
Published: June 2021

Age‐related macular degeneration (AMD) is the leading cause of "central vision" loss in people 60 years of age or older. In AMD there is progressive degeneration of retinal pigment epithelium (RPE) and the photoreceptors in the macular area of the retina. Docosahexaenoic acid, the precursor of neuroprotectin D1 (NPD1), is concentrated in photoreceptor outer segments. Our laboratory has reported that NPD1 inhibits oxidative‐stress‐mediated proinflammatory gene induction and apoptosis, and consequently promotes RPE cell survival. Recent studies have shown that oxidative stress, leading to apoptosis, neovascularization and lipid peroxidation, participates in AMD pathogenesis.Apoptosis is mediated by a well‐orchestrated interaction between the anti‐apoptotic and pro‐apoptotic members of the Bcl‐2 family. Bcl‐xL is one such anti‐apoptotic protein involved in this intracellular signal trans‐duction. Bcl‐xL ‐/‐ mice are prone to early death, succumbing to a massive loss of neurons in the brain. In vitro studies have shown that the neuronal yield was increased in cultures of mouse embryonic stem cells when Bcl‐xL was over‐expressed. In this study, we describe the regulation of Bcl‐xL through mitogen activated protein kinase pathway. We also show that NPD1 significantly downregulated the activation of phos‐phorylated Bcl‐xL when induced with oxidative stress. The long term goal of this project is to better understand mechanisms of neuroprotection mediated by NPD1.NIH/NEI Grant RO1 EY05121.
Oxidative stress response and trafficking of platelet‐activating factor acetylhydrolase type II (PAFAH‐II)
Authors: Fuzaylova Anastasia G. , Sedlack Elizabeth M. , Winget Jason M. , Bahnson Brian J. 
Published: June 2021

Platelet activating factor acetylhydrolase type II (PAFAH‐II) is a member of the phospholipase A2 subfamily that can hydrolyze and inactivate platelet activating factor and oxidatively fragmented phospholipids at the sn‐2 position. This enzyme is a 44kDa, intracellular, myristoylated protein that becomes associated with the inner membranes under oxidative stress, thus maintaining cell membrane integrity. In order to elucidate the precise mechanism of the stress response and trafficking of this protein, the role of the myristoyl tail was investigated. Trafficking of myristoylated, wild type PAFAH‐II, and of a mutant (Gly‐2‐Ala) that cannot be myristoylated, was monitored in live cells using fluorescent protein fusion tags. Confocal microscopy indicates that unmyristoylated PAFAH‐II remains cytoplasmic under both stressed and unstressed conditions. In contrast, myristoylated PAFAH‐II, which is only partially localized to the inner membranes prior to stress, becomes more concentrated in the inner membranes upon stress. Therefore, this study shows that the myristoyl tail plays a key role in this oxidative stress response. The possible roles of additional regulatory mechanisms, such as residue modifications, which may be facilitating the exposure of the myristoyl tail for membrane anchoring, are also the focus of our current investigations.Support: COBRE 2P20RR015588 and 1R01HL084366
Metabolism and Biological Activity of Sulindac and its Epimers
Authors: Brunell David , Marchetti Maria , Gamliel Edna , Sagher Daphna , Brot Nathan , Weissbach Herbert , Binninger David 
Published: June 2021

Sulindac can be oxidized to sulindac sulfone and reduced to sulindac sulfide, an active cyclooxygenase (COX) inhibitor. However, the metabolism and biological activities of the individual R and S epimers are not known. In vivo, the R epimer yielded higher plasma levels of the sulfone, whereas the S epimer was more readily reduced to the sulfide. In a hepatoma cell line, both epimers activated the aryl hydrocarbon receptor and significantly induced cytochrome P450 enzymes. The R epimer was oxidized to sulindac sulfone more readily than the S epimer. A rat liver cell extract reduced both the R and S epimers of sulindac with either DTT or thioredoxin. The S epimer is primarily reduced by methionine sulfoxide reductase A (MsrA). The enzyme(s) responsible for reduction of the R epimer has been partially purified.Sulindac enhances killing of human colon, skin, and lung cancer cells by oxidative stress. The effect does not involve COX inhibition or the Msr system. An increase in reactive oxygen species (ROS) and loss of mitochondrial membrane potential suggest that cell death is due to apoptosis. Both epimers were effective under the conditions used. In contrast, no enhanced killing was observed using either epimer with normal cells under the same conditions. In summary it appears that the R and S epimers of sulindac are metabolized by different pathways and that these epimers may have different pharmacological properties.