bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generation of a Gelatin‐Based, Vancomycin‐Eluting Hemostatic Agent for the Prevention of Surgical Site Infections
Authors: Fralish Zachary , Shelby Shameka J 
Published: April 2020

Surgical site infections (SSIs) following major surgeries are a growing concern in the healthcare industry. These infections lead to lengthened hospital stays, additional surgical procedures, prolonged antibiotic use, and increased patient morbidity. Vancomycin is often the last line of defense against strains of staphylococcal and streptococcal bacteria that are resistant to beta‐lactam antibiotics including Methicillin‐Resistant Staphylococcus Aureus (MRSA). Upon the event of SSIs, typical treatment includes the intravenous delivery of vancomycin which leads to lengthened hospital stays and increased patient expenditures. Current prevention methods include oral administration of antibiotics before surgery, coating of antiseptic agents on incision sites and operating utensils, and systemic administration of antibiotics during surgery. With widespread delivery of antibiotics, there is an increased likelihood of further expansion of antimicrobial resistance. The development of a localized antibiotic‐eluting hemostatic agent as a preventative measure will likely improve the efficiency and efficacy of antimicrobial prophylaxis and subsequently reduce the occurrence of SSIs. Therefore, the current investigation identified a methodology to produce a vancomycin‐linked hemostatic agent through liquid‐phase peptide bond formation. Type B gelatin was incubated with vancomycin and the cross‐linking agent 1‐ethyl‐3‐(‐3‐dimethylaminopropyl) carbodiimide (EDC) to allow for internal cross‐linking of gelatin and conjugation of gelatin with vancomycin. Concentrations of gelatin, EDC, and vancomycin were optimized through release profile analysis. Analysis of eluted fractions by UV‐Vis spectrometry indicated that approximately 30% of loaded vancomycin was released over a two week period. Further analysis by infrared spectroscopy and UV‐Vis spectrometry confirmed that vancomycin released from the loaded hemostatic agent maintained its structural integrity following the cross‐linking procedure. The method described here allows for the production of a vancomycin‐eluting hemostatic agent for the prevention of SSIs. Incorporation of this technology into post‐operative procedures may expedite surgical protocols and limit cost burdens and mortality rates associated with SSIs. On‐going work will analyze the efficacy and toxicity of these agents within biological systems.Support or Funding InformationFlorida Southern College Department of Chemistry, Biochemistry, & PhysicsBerend Research Funds
An Invitation to Modeling
Authors: Dahlquist Kam D. 
Published: April 2020

As part of an working group at the National Institute for Mathematical and Biological Synthesis (NIMBioS), I joined an an interdisciplinary group of biologists, mathematicians, mathematical biologists, and education researchers who came together to address the challenges of teaching modeling. This working group provided the opportunity over two years to explore the education research on modeling, share how modeling is applied and taught in our various disciplines, and examine our individual teaching experiences for best practices. In the process, members of the group became more thoughtful in our practice and have developed more granular, nuanced, and inclusive definitions of models and modeling in a broad sense, and mathematical modeling in particular (Eaton et al., 2019; doi: 10.1080/10511970.2018.1489318). This has led to insight about how we might improve our approach to teaching with models in biology courses (Dahlquist et al., 2017; doi: 10.7287/peerj.preprints.3215v1). Models and the process of modeling are fundamental to the discipline of biology, and therefore should be incorporated into undergraduate biology courses. Models are ubiquitous in biology, including representations of the process of science itself. We advocate for a model of the process of science that highlights parallel tracks of mathematical and experimental modeling investigations. With this recognition, we suggest ways in which instructors can call students’ attention to biological models more explicitly by using modeling language, facilitating metacognition about the use of models, and employing model‐based reasoning. We then provide guidance on how to begin to engage students in the process of modeling, encouraging instructors to scaffold a progression to mathematical modeling. I will discuss how I use this framework in a lower division sophomore‐level Cell Function course and upper division courses in Molecular Biology, Bioinformatics, and Biomathematical modeling. We suggest that by making even a small shift in the way models and modeling are discussed in the classroom, students gain understanding of key biological concepts, practice realistic scientific inquiry, and build quantitative and communication skills.Support or Funding InformationThis work was conducted as part of the “Unpacking the Black Box: Teaching Quantitative Biology” Working Group at the National Institute for Mathematical and Biological Synthesis (NIMBioS), sponsored by the National Science Foundation through NSF Award #DBI‐1300426, with additional support from The University of Tennessee, Knoxville. Working group members included: Melissa L. Aikens, Joseph T. Dauer, Samuel S. Donovan, Carrie Diaz Eaton, Hannah Callender Highlander, Kristin P. Jenkins, John R. Jungck, M. Drew LaMar, Glenn Ledder, Robert L. Mayes, and Richard C. Schugart.
Genetic ablation of bone marrow beta‐adrenergic receptors alters miRNA‐transcriptome networks for microglia activation and inflammation in the paraventricular nucleus of the hypothalamus
Authors: Martyniuk Chris J. , Martinez Ruben , Kostyniuk Dan , Mennigan Jan , Zubcevic Jasenka 
Published: April 2020

Hypertension (HTN) is a preventable condition with complex etiology. Neurogenic origins of HTN such as aberrant signaling in the paraventricular nucleus (PVN) of the hypothalamus remain a high priority for therapeutic interventions, as most anti‐HTN treatments remain ineffective in a significant portion of patients. Discerning the molecular mechanisms underlying neurogenic HTN is critical for understanding how an overactive sympathetic drive contributes to high blood pressure. We generated a novel bone marrow‐specific adrenergic beta 1 and beta 2 knockout mouse chimera (AdrB1.B2 KO mouse) to study how sympathetic drive to the bone, or lack thereof, affects the molecular responses in the PVN. These mice have previously been characterized by dampened systemic immune responses and decreased blood pressure during the active period. Here, loss of sympathetic drive in the AdrB1.B2 KO chimera lead to an overwhelming suppression of transcriptional networks in the PVN that included leukocyte cell adhesion and migration as well as lymphocyte activation and adhesion, and T cell‐ activation and recruitment. Furthermore, transcriptome networks associated with astroglia, microglial, and neuronal function were suppressed in the PVN of AdrB1.B2 KO chimera. Transcriptional networks related to IL‐17a signaling and the renin‐angiotensin system related genes were also suppressed in the PVN of the AdrB1.B2 KO chimera. Using computational predictive tools, we identified a number of miRNAs expected to regulate global transcriptome responses in the PVN. These included miR‐27b3p, miR‐150, miR‐223, and miR‐326, some of which have been implicated in HTN. In addition, using qPCR, we observed a downregulation in the relative expression of miR‐150, miR‐205, miR‐223, miR‐375, miR‐499a, and miR‐27b3p in the PVN of AdrB1.B2 KO chimera, thus in part confirming the results of computational predictive tools. This study identifies novel molecular mechanisms involved in neural‐immune interactions that underlie neurogenic HTN and elucidate new pathways for therapeutic intervention.Support or Funding InformationSupported by AHA grant 14SDG18300010 to JZ and NIH R21AT010192 Award AWD05242 P0104932 to CJM and JZ.
Evaluation of Common Crosslinking Agents, Glutaraldehyde and EDC, for the Magnetic Isolation of Phagosomes from Cultured Retinal Pigment Epithelial Cells
Authors: Norberg Ashley , Shelby Shameka J. 
Published: April 2020

Daily exposure of photoreceptors to light leads to damage and subsequent shedding of the photoreceptor outer segments (OS). The retinal pigment epithelium (RPE) is responsible for internalization, processing, and recycling of the shed photoreceptor OS. This phenomena, termed RPE phagocytosis, proceeds through a relatively unknown mechanism. To study RPE phagocytosis, previous studies labeled OS with magnetic nanoparticles through a glutaraldehyde cross‐linker to allow for magnetic isolation of phagosomes from the RPE. While isolation of phagosomes from the glutaraldehyde cross‐linking method was successful, the addition of this linker may impact the phagocytic ingestion pathway. Comparatively, 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide (EDC), a zero‐length cross‐linker, may be used to create a direct cross‐link between the carboxylic acids of the OS protein and the amines of prepared magnetite particles. As such, the purpose of this study was to compare the outcomes of linking OS to nanomagnetites via glutaraldehyde and EDC. To prepare the nanomagnetites, Fe3O4 particles coated with primary amine groups were centrifuged to separate nanoparticles from larger particles. The nanomagnetites were then linked to purified bovine OS with either glutaraldehyde or EDC for 3 hours or 15 minutes, respectively. Linked OS were then fed to cultured RPE cells for 4 hours. Cells were washed and then gently lysed using dounce homogenization to obtain intact phagosomes. Lysed cells were subjected to a magnetic field to separate phagosomes containing magnetite‐labeled OS from the remainder of the lysate. Immunoblot analysis of the purified phagosomes confirmed the presence of rhodopsin, a major component of OS, in both methods. In addition, isolated phagosomes from both methods were shown to contain proteins typically known to be associated with phagosomes including Rab 5, EEA1, and Annexin V. These results suggest that linkage of nanomagnetites to OS with either glutaraldehyde or EDC can serve as efficient methods to accomplish purification of phagosomes from the RPE. Due to the readily tunable linkage conditions, ease of use, and the formation of a direct peptide bond between the magnetite and OS, linkage of nanomagnetites to OS with EDC can serve as a more effective method for purification of phagosomes from RPE cells. Analysis of RPE phagosomes isolated by magnetic selection will contribute to the further elucidation of the RPE phagocytic process.Support or Funding InformationFlorida Southern College Department of Chemistry, Biochemistry, & Physics
Endothelial Permeability Following Skeletal Muscle Injury in Males Versus Females Ages 4 weeks to 1 Year.
Authors: Tusavitz Sabrina , Lee Hannah , Carpenter Apeil 
Published: April 2020

Capillary permeability following skeletal muscle injury is necessary for the entry of blood cells and plasma factors necessary for healing. However, it is unclear how aging and sex differences affect capillary permeability after muscle injury.PURPOSETo compare endothelial permeability 48 hours post skeletal muscle injury between male and female mice at 1, 3, 6 and 12s month of ag between male and female mice.METHODSBarium chloride (BaCl2) was injected into the left tibialis anterior(TA) to create a chemical injury and sodium chloride (NaCl) was injected into the right leg as a control. Evans Blue (EB) dye was injected through the lateral tail vein at 48 hours post‐injury. The mouse was sacrificed 30 min following EB injection and both TA’s were removed, weighed and soaked in formamide to remove extravasated EB from the muscles. Absorbance of extravasated EB was measured. To determine the effect of testosterone and estradiol on permeability, castrated and ovariectomized mice at 12 weeks of age were tested for permeability using Evan’s Blue dye injection 48 hours after injury.RESULTSPermeability 48 hours post‐injection was significantly elevated in the BaCl2 injected muscles of mice aged 4 weeks compared to NaCl Male: 6.53±0.1.25 vs. 16.68±8.712 ngEB/mgTA, p<0.001; Female: 2.435±1.56 vs. 9.411±2.799, p<0.01). Permeability 48 hours post‐injection was significantly elevated in the BaCl2 injected muscles of mice aged 12 weeks compared to NaCl Female: 3.02 + 2.43 vs. 16.425 ± 6.63, p<0.0001). Permeability 48 hours post‐injection was significantly elevated in the BaCl2 injected muscles of mice aged 6 months compared to NaCl Male: 2.2743 + .0.932 vs. 8.37 ± 81.66 ngEB/mgTA, p<0.01; Female: 1.593 ±.0.991 vs. 6.3 ± 4.846, p<0.001). Permeability 48 hours post‐injection was significantly elevated in the BaCl2 injected muscles of mice aged 12 months compared to NaCl Male: 1.55 ± 0.32 vs. 4.371 ± 0.299 ngEB/mgTA, p<0.01; Female: 2.78 + 0.79 vs.. 12.02 ± 2.84, p<0.0001). Following castration, permeability in male mice at 12 weeks was not significantly different than non‐castrated mice (5.64 ± 1.033; 7.505 ± 2.131vs 4.927 ± 0.549 vs. 7.505 ± 2.131, respectively). Following ovariectomy, permeability in female mice at 12 weeks was not significantly different than non‐ovariectomized mice (3.02 + 2.43 vs. 16.53 ± 6.63; 4.927 ± 0.549 vs. 9.152 ± 2.96, respectively)CONCLUSIONBoth age and gender contribute to permeability 48 hrs post‐skeletal muscle injury. This affect does not appear to be dependent on testosterone or estradiol.
Activation of nicotinic acetylcholine receptors induces potentiation and synchronization within in vitro hippocampal networks
Authors: Djemil Sarra , Chen Xin , Lee Jisoo , Rauf Mikael , Pak Daniel T.S. , Dzakpasu Rhonda 
Published: April 2020

Nicotinic acetylcholine receptors (nAChRs) are known to play a role in cognitive functions of the hippocampus, such as memory consolidation. Given that they conduct Ca2+ and are capable of regulating the release of glutamate and γ‐aminobutyric acid (GABA) within the hippocampus, thereby shifting the excitatory‐inhibitory ratio, we hypothesized that the activation of nAChRs will result in the potentiation of hippocampal networks and alter synchronization. We used nicotine as a tool to investigate the impact of activation of nAChRs on neuronal network dynamics in primary embryonic rat hippocampal cultures prepared from timed‐pregnant Sprague‐Dawley rats. We perturbed cultured hippocampal networks with increasing concentrations of bath‐applied nicotine and performed network extracellular recordings of action potentials using a microelectrode array (MEA). We found that nicotine modulated network dynamics in a concentration‐dependent manner; it enhanced firing of action potentials as well as facilitated bursting activity. In addition, we used pharmacological agents to determine the contributions of discrete nAChR subtypes to the observed network dynamics. We found that β4‐containing nAChRs are necessary for the observed increases in spiking, bursting and synchrony, while the activation of α7 nAChRs augments nicotine‐mediated network potentiation but is not necessary for its manifestation. We also observed that antagonists of N‐methyl‐D‐aspartate receptors (NMDARs) and group I metabotropic glutamate receptors (mGluRs) partially blocked the effects of nicotine. Furthermore, nicotine exposure promoted autophosphorylation of Ca2+/calmodulin‐dependent kinase II (CaMKII) and serine 831 phosphorylation of the α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor (AMPAR) subunit GluA1. These results suggest that nicotinic receptors induce potentiation and synchronization of hippocampal networks and glutamatergic synaptic transmission. Findings from this work highlight the impact of cholinergic signaling in generating network‐wide potentiation in the form of enhanced spiking and bursting dynamics that coincide with molecular correlates of memory such as increased phosphorylation of CaMKII and GluA1.Support or Funding InformationNational Science Foundation (PHY‐1205919 and IOS‐ 1755033), National Institutes of Health (RF1 AG056603‐01) and the Georgetown‐MedStar CERSI Scholars program.
Development of Hypertension and Cardiac Hypertrophy is associated with Endothelial Cell Dysfunction in Npr1 Gene‐disrupted Mice
Authors: Das Subhankar , Noland Whitney , Periasamy Ramu , Krazit Stephen T. , Pandey Kailash N. 
Published: April 2020

Atrial and brain natriuretic peptides (ANP and BNP) are cardiac hormones that elicit natriuretic, diuretic, vasorelaxant, and antiproliferative responses, all of which contribute to lowering blood pressure and blood volume. ANP and BNP bind to guanylyl cyclase ‐A/natriuretic peptide receptor ‐A (GC‐A/NPRA), which is considered to be the major natriuretic peptide receptor that synthesizes the intracellular second messenger cGMP. The objective of the present study was to examine the effect of Npr1 (coding for NPRA) gene‐disruption on the process of endothelial cell dysfunction in the development of hypertension and cardiac hypertrophy. We used six‐month old mice having different copies of Npr1 gene (0‐copy, 1‐copy, and 2‐copy). The blood pressure and echocardiographic measurements were performed in each group. Blood was collected by direct cardiac puncture and cardiac tissues were harvested and snap frozen in liquid nitrogen. The 0‐copy (Npr1−/−) mice showed 35–45 mmHg higher systolic blood pressure (SBP) as compared to 2‐copy (Npr1+/+) mice. Echocardiographic measurements of Npr1 gene‐disrupted 1‐copy (Npr1+/−) and 0‐copy mice showed significant increased LVEDD (27% in 0‐copy and 10% in 1‐copy mice), intraventricular septal wall thickness (IVSTDD, 30% in 0‐copy and 15% in 1‐copy mice), and reduced fractional shortening by 24% in 0‐copy and 12% in 1‐copy mice as compared with control mice. There was also a significant increase in plasma levels of plasminogen activator inhibitor‐1 (PAI‐1; 2.2‐fold), soluble intracellular adhesion molecule (sICAM; 1.8‐fold), soluble vascular cell adhesion molecule (sVCAM; 30%). In the present study, increased plasma levels of sICAM, sVCAM, and PAI‐1 suggested the involvement of endothelial cell dysfunction in producing cardiac hypertrophy in Npr1 null mutant mice. Our results implicate that ANP/NPRA signaling promotes inhibitory effect on the agents, which cause endothelial dysfunction in the heart leading to cardiac hypertrophy and cardiac remodeling.Support or Funding InformationThis work was supported by NIH grant (HL062147).
Histone 3 Lysine 9 Methylating Enzyme G9a Regulates Transcriptional Expression of Nuclear Receptors and Cytochrome P450 Genes in HepaRG Cells
Authors: Pande Parimal , Zhong Xiao-bo , Ku Warren 
Published: April 2020

Histone modification transcriptionally regulate gene expression. Cytochrome P450 genes are studied extensively in terms of regulation of expression through histone modification. Histone 3 lysine 4 (H3K4) and Histone 3 lysine 27 (H3K27) methylation are studied extensively in regulation of P450 gene expression. Another histone modification Histone 3 lysine 9 methylation, is well known for transcriptional repression of genes but not studies well in regulation of nuclear receptors and cytochrome P450 gene expression. In this study, the role of histone methyl transferase G9a, which is responsible for mono and di‐methylation of histone 3 lysine 9 residue, was studied in regulation of drug metabolizing enzymes and nuclear receptors. We treated HepaRG cell with small interfering RNA to selectively knockdown EHMT2 mRNA and using adenovirus, G9a was overexpressed to study the effect on nuclear receptors CAR (NR1I3), PXR (NR1I2), AHR and heterodimer partner RXRα along with the selected drug metabolizing cytochrome P450 genes. In pathological conditions such as steatosis, the expression of nuclear receptors and cytochrome P450 genes is affected along with G9a in a mice model treated with high fat diet. In this study, we treated HepaRG cells with fatty acids to induce steatosis. In conclusion we observed that loss of G9a shown to decrease mRNA expression of nuclear receptors and cytochrome P450 genes whereas overexpression of G9a increased expression of nuclear receptors CAR (NR1I3), PXR (NR1I2)and selected drug metabolizing enzymes CYP1A2, CYP2B6, CYP2C9, CYP3A4 etc. In fatty acid treated cells overexpression of G9a was observed to prevent fatty acid mediated down regulation of nuclear receptor CAR (NR1I3) and drug metabolizing enzyme genes CYP2C19, CYP2C8 and CYP3A4.Support or Funding InformationThis project work was funded by Boehringer Ingelheim Pharmaceuticals
The Effects of Diet‐Induced Obesity in Male Sprague Dawley Rats on Blood Glucose, Ketones and Markers of Mental and Physical fatigue
Authors: Kaviani Sepideh , Niepoetter Paige , Viernow Coral , Ruholl Hannah , Gopalan Chaya 
Published: April 2020

ObjectivePrevious studies on the pathology of obesity and obesity‐induced metabolic disorders utilized genetically modified obese rat models. To better mimic the onset and the physiology of obesity in humans, the use of diet‐induced obese rat models is lacking. Therefore, the purpose of this study is to induce obesity in Sprague Dawley rats by administering a high fat (HF) diet and to further investigate the effects of obesity on blood glucose and ketone concentrations as well as locomotor and mental activities as indicators of fatigue.MethodsFifty‐four 7‐week‐old male Sprague Dawley rats were randomized into either a high‐fat diet (HFD) group (n=28) or a standard diet (SD) group (n=26). All rats were housed in individual cages under controlled laboratory conditions and had access to food and water ad libitum. The HFD group received a HF diet (60% fat, 20% CHO, and 20% Pr) for six weeks, while the SD group received a standard diet (17% fat, 56% CHO, 27% Pr). Body weight (BW) was measured weekly and blood glucose and ketones were measured twice a week for 6 weeks. The open field test (OF) was conducted daily for 8 days in week 5, followed by Novel object recognition (NOR) testing at 4 separate days during week 6.ResultsBoth groups gained weight from week 1 to week 6 (HFD: 223.0±16.2g vs. 387.7±23.6g, p<0.001; at week 1 vs. week 6, respectively, SD: 215.0±15.9g vs. 361.5±23.6g, p<0.001; at week 1 vs. week 6, respectively). However, the average within‐subject BW gain was greater in the HFD compared to the SD (168.1±21.6g vs 130.1±16.9g, p<0.001; HFD vs. SD, respectively). Although the average glucose levels were not different between the two groups throughout the study, the HFD showed higher fluctuations of blood glucose levels and at week 4 they had higher glucose levels than the SD (104.1±11.2mg/dL vs. 96.6±6.9mg/dL, p=0.005; for HFD vs. SD, respectively). Ketone levels were not different between the two groups. Although there were no overall differences in OF and NOR test results in HFD vs. SD, the difference between the recognition time of the familiar vs. the novel object in the HFD tended to be smaller than that of the SD at all 4 days of NOR testing (p=ns).ConclusionsThe HF diet results in significant weight gain consistent with obesity in the majority of rats within a 6‐week period of receiving the diet. Overall, diet‐induced obesity was not found to have adverse effects on glucose and ketone levels. However, it might negatively affect memory and lead to mental fatigue in rats.