bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving Biofuel Production with Metagenomics and Synthetic Biology
Authors: Witt Evan , Forsberg Kevin , Ellison Tyler , Dantas Gautam
Published: June 2021

The Department of Energy has expressed considerable interest in the production of biofuels from lignocellulose. Lignocellulose represents the largest terrestrial carbon source on Earth, but cannot be broken down without a combination of acids, industrial chemicals and heat. Only after treatment with these harsh conditions can the sugars within lignocellulose be made available for conversion into fuels (i.e. ethanol or isobutanol) by engineered strains of Escherichia coli.

Unfortunately, this treatment process also creates compounds that inhibit bacterial growth and limit the potential output of biofuels.

We have shown that genes isolated from soil metagenomes can confer tolerance to the products of biofuel production, which include fuels like ethanol and isobutanol, and the toxic products from lignocellulose treatment (e.g. furfural, ferulic acid, and others). Increasing tolerance to these byproducts can theoretically increase the yield of biofuel producing strains of E. coli, which is our ultimate goal.

We aim to demonstrate the viability of a workflow combining synthetic biology and metagenomics to address innumerable challenges in industry and bioremediation. This workflow is not only versatile and adaptable, but also scalable, and could have tremendous economic and environmental potential.
Study of Methyletransferase RumB in E. coli
Authors: Pritts Jordan , Zilinskas Egidijus
Published: June 2021

In this experiment methyltransferases RumA and RumB were studied. These proteins are part of a group of enzymes that conduct post transcriptional modifications on RNA. RumB specifically methylates uracil 747 on the 23S subunit of ribosomal RNA. RumA methylates uracil 1939 on the 23S subunit of ribosomal RNA. Both RumA and RumB transfer a methyl group from a donor molecule (S‐Adenosylmethionine) to a receptor molecule (uracil on RNA). These two proteins share significant similarity in sequence as well as the incorporation of an Fe‐S cluster. Due to the similarity it is proposed that RumB should follow RumA characteristics. The RumA and RumB genes were successfully amplified using PCR, ligated into a plasmid, transformed, sequenced, and induced. The proteins were expressed using the pET‐45b expression vector. Cell lysis was not successful as the protein of interest remained in the cell pellet as opposed to the supernatant. Future research will include protein purification and analysis.
Genetic deletion of an instability motif in the Tristetraprolin (TTP) transcript increases TTP mRNA stability and protein expression and provides protection against inflammatory diseases
Authors: Patial Sonika , Blackshear Perry
Published: June 2021

Objective

Tristetraprolin (TTP) is an mRNA binding protein that binds to AU‐rich elements (AREs) in the 3′‐untranslated regions (3′UTR) of specific mRNAs, such as tumor necrosis factor (TNF) mRNA, and increases their rates of deadenylation and turnover. TTP mRNA also contains AREs within its own 3′UTR that are partly responsible for its own instability. The objective of this study was to test the hypothesis that increased TTP mRNA stability, and the resulting increased TTP protein expression, may provide protection against inflammatory diseases.

Results

Using knock‐in technology, a novel TTP mouse line (TTPΔARE) was generated in which 136 bases in the 3′UTR AU‐rich region of TTP mRNA were deleted. TTPΔARE mice developed and reproduced normally, and exhibited no phenotypic or histopathological abnormalities. TTP mRNA stability was found to be significantly enhanced in bone marrow‐derived macrophages (BMDMs) and mouse embryonic fibroblasts (MEFs) isolated from TTPΔARE mice. Moreover, TTP protein expression was increased in unstimulated and LPS‐stimulated BMDMs, and in various mouse tissues. In addition, LPS‐induced expression of TTP target mRNAs, particularly TNF and Il‐1β mRNAs, was significantly reduced in TTPΔARE BMDMs. TTPΔARE mice exhibited reduced skin inflammation in an experimental model of psoriasis, and were completely protected from collagen antibody‐induced arthritis.

Conclusions

Our data demonstrate that modestly increased levels of TTP in mouse cells and tissues are protective against certain inflammatory disease models. These data may have implications for the development of therapeutic strategies to target chronic inflammatory diseases via enhancing TTP expression.
Structural Bioinformatics and Molecular Dynamics of p53 Tumor Suppressor Protein
Authors: Thayer Kelly , Slaw Benjamin , Han In , Quinn Taylor
Published: June 2021

In carrying out its tumor suppressor function, p53 binds to cognate DNA regulatory sites throughout the genome. While many of the binding sites contain a recognizable consensus, other binding sites exist which lack this, making this an interesting system for understanding the potential role of indirect readout in the binding event. In order to study this, we are constructing additive energy models based on hydrogen bond contacts and the presence of the TG DNA base pair step. The simplest model simply counts how many of the crystallographic bonds are available for a particular DNA sequence based on H‐bond donor and acceptor groups, and the model is made increasingly complex through refinements including distance dependence and angle of the H‐bonds. Based on the score from the additive model, clustering of experimentally determined DNA binding sites led to the identification of five distinct classes of binding sites, which we hypothesize represent distinct modes of binding. To further investigate this hypothesis, we have carried out molecular dynamics simulations of the p53 protein complexed with DNA representative of the different clusters, as well as engineered sequences expected to have interesting mechanical properties. Furthermore, we have examined molecular dynamics involving lys120, a key residue interacting with the DNA. Our results shed light on the dynamic interaction of p53 and its binding sites and suggest novel means by which the recognition process may occur. This mechanistic understanding lays groundwork that informs the development of more robust cancer therapeutics.

Funding: Vassar College Spring 2014 Research Committee Award from the Emily Abbey Fund, the Christian A. Johnson Endeavor Foundation, and the Elise Nichols and Margaret Sawyer Biochemistry Research Fellowship
Binding Determinates of Sodium Hydrogen Exchanger 1 for Calcineurin Homologous Protein Isoforms 1 and 2
Authors: Jevaughn Davis , Marshall Chelsea , Wallert Mark , Provost Joseph
Published: June 2021

The Sodium Hydrogen Exchanger, (NHE1) is an ubiquitously expressed protein that exchanges an intracellular proton (H+) for an extracellular sodium (Na+) and regulates cell volume, intracellular pH homeostasis and cell motility. The Calceurin Homologous Protein isoforms 1 (CHP1) and isoform 2 (CHP2) each regulate NHE1. CHP1 and CHP2 share a 66% amino residue homology, yet CHP1 and CHP2 have different binding affinities for NHE1. No work has determined the differential binding site for each CHP isoform. Here we will show the binding determinates of NHE and the CHP Isoforms by mutagenesis of key amino residues in the CHP binding domain from AA 803‐845. Sequence and structural analysis demonstrated that eight amino residues may play an important role in the binding of NHE1 and the CHP isoforms. These key amino residues are Asn519Ala, Asn519Asp, Ile518Gln/Ile522Gln, Il534Lys, Il537Lys, His523Gly, His523Ile, and Asp536Gly. We have expressed and purified the c‐terminus of wild‐type NHE1 and mutations for each putative CHP interaction site. The protein interactions of recombinant CHP1 and CHP2 is determined using thermal denaturation and other biophysical methods. This work will identify potential interaction sites in common and unique for each CHP isoform and NHE1.
Profiling of Lipids Expression Along the Rostral and Caudal Axis After Spinal Cord Injury: Matrix Assisted Laser Desorption/Ionization Approach
Authors: Adam Amna , Salzet Michel , Devaux Stephanie
Published: June 2021

Spinal cord injury (SCI) causes alteration in lipid composition and migration of lipids between the gray and white matter regions of spinal cord. Studying the prominent and region‐specific lipids in injured spinal cords can possibly lead to clinical understanding of the specific role each class of lipid plays in the inflammation process after SCI. Utilization of Matrix Assisted Laser Desorption/Ionization (MALDI)‐TOF/TOF coupled with FlexImaging and ClinProTools software for statistical analysis was imployed as a method to identify lipids that demonstrate interesting behavior post SCI. Furthermore, shotgun analysis using Q Exactive performed to possibly characterize interesting lipids.

Using MALDI‐Mass Spectrometry, the region‐specificity of lipid expression and alteration in injured spinal cord were identified with progression of time. Rat tissues from 3, 7, 10 days post SCI were imaged in both negative and positive mode and revealed that visualization of region‐specific lipid is best carried in the positive reflector mode. Shotgun analysis using Orbitrap allowed for approximate characterization of the lipids with m/z ratio identified using MALDI imaging. Taking all together the data suggests that in the positive reflector mode, there is a difference in the expression in rostral and caudal region, and glycerophospholipids is possibly the most prominent class of lipid in both gray and white matter region of spinal cord post SCI.
Cellular mechanisms by which alcohol promotes HIV protease inhibitor‐induced liver lipotoxicity
Authors: Hinton Michael , Pandak William , Hylemon Phillip , Zhou Huiping
Published: June 2021

The development of highly‐active‐antiretroviral therapy(HAART) has allowed management of HIV and extended the lives of those infected. Alcohol abuse, which is very common in HIV‐1 infected patients, is one of the most important co‐morbid risk factors for liver injury and has been associated with the occurrence of serious metabolic syndrome and subsequent discontinuation of HAART in HIV patients. We have identified endoplasmic reticulum (ER) stress‐induced proapoptotic factor CHOP as an important factor underlying HIV PI‐induced inflammation and hepatic lipotoxicity. However, little is known about the mechanistic pathways by which alcohol promotes HIV PI‐induced hepatic lipotoxicity. The aim of this study was to determine if inhibition of CHOP expression prevents alcohol‐ and HIV PI‐induced apoptosis and dysregulation of lipid metabolism.

Methods

Primary hepatocytes from wild type or CHOP‐/‐ mice were treated with individual HIV PIs with or without alcohol. Activation of the key genes responsible for lipid metabolism was determined by real time RT‐PCR and Western Blot.

Results

CHOP‐/‐ mice prevent ethanol and HIV PI‐induced dysregulation of key genes involved in lipid metabolism in hepatocytes. CHOP‐/‐ hepatocytes treated with alcohol showed decreased biosynthesis of cholesterol, fatty acid, and bile acid.

Conclusions

Activation of the ER stress‐induced proapoptotic factor CHOP is a key cellular mechanism underlying alcohol and HIV PI‐induced hepatotoxicity. CHOP expression is key for alcohol and HIV PI‐induced dysregulation of key genes involved in lipid metabolism in hepatocytes.
Phospholipase D2 Regulation of MT1‐MMP Membrane Trafficking Promotes Breast Cancer Metastasis
Authors: Du Guangwei , Wang Ziqing , Zhang Feng , Rog Colin , Lu Maryia , Peng Junmin , Di Paolo Gilbert
Published: June 2021

Metastasis is the major cause of breast cancer death. However, despite considerable progress, the signaling events specifically driving cancer cell invasion and metastasis remain largely unknown. In this study, we show that removal of the gene encoding phospholipase D2 (PLD2), which generates the signaling lipid phosphatidic acid (PA), strongly reduced circulating tumor cells and lung metastases in the MMTV‐Neu breast cancer mouse model, whereas it had no effect on tumor initiation and growth. Consistently, migration, invasion and invadopodia, were greatly reduced in primary mouse tumor cells and human breast cancer cell lines lacking PLD2, suggesting that PLD2 promotes tumor metastasis by regulating the local invasion of tumor cells. A PA‐binding protein screening and biochemical analyses revealed that PA specifically binds to a motor protein, Kinesin‐1, and regulates its association with intracellular vesicles. Inhibition of the PLD2‐PA‐Kinesin‐1 pathway by inhibitors or PLD2 knockout blocked the plasma membrane targeting of MT1‐MMP, a matrix metalloproteinase that is required for cancer cell invasion and invadopodia formation. Taken together, these results indicate that PLD2‐generated PA promotes breast cancer metastasis by regulating membrane trafficking of proteins that are critical for cancer cell invasion, and identify that PLD2 is a potential target for treating metastatic breast cancer.
Characterization of Two Inositol Hexakisphosphate Kinases, AtVIP1 and AtVIP2, in Arabidopsis
Authors: Williams Sarah Phoebe , Land Eric , Donahue Janet , Rangarajan Padma , Mandal Mihir , Perera Imara , Gillaspy Glenda
Published: June 2021

Myo‐inositol phosphates (InsPs) are critical signaling molecules used by eukaryotes, with roles in nutrient and abiotic stress sensing/signaling. The newest members of this family are the inositol pyrophosphates which contain diphospho‐ or triphospho‐ (PPx) moieties at one or more positions on the inositol ring. These molecules have recently been identified across the plant kingdom and their synthesis in Arabidopsis is the result of two highly similar genes, AtVIP1 and AtVIP2. We report the spatial/temporal expression of these genes using real‐time PCR and promoter:GUS analysis and the subcellular localization of the VIP proteins, using transient expression of GFP fusion proteins in Nicotiana benthamiana. Both VIPs are localized in the endoplasmic reticulum, with AtVIP1 additionally localizing to the nucleus. These studies further our understanding of the distinct role each VIP may play in the plant. Mutants lacking expression of both AtVIP1 and AtVIP2 genes have been identified and are viable. Work is on‐going to determine the impact of inositol pyrophosphate synthesis in these double mutants.
Evaluating 2‐0, 3‐1 Desulfated Heparin (ODSH) Dosing for Radiation Combined Burn Injury
Authors: Islam A , Bolduc D , Zhai M , Hobbs S , Swift J
Published: June 2021

Victims of radiation events succumb to serious infections as a consequence of bacterial translocation and sepsis. Exacerbation of the risk of infection by radiation combined burn injury (RCBI) further heightens vulnerability. No suitable countermeasures for RCBI exist. We evaluated ODSH, an anticoagulant and anti‐inflammatory agent as a potential countermeasure to RCBI. Female mice (12‐week, B6D2F1/J) were subjected to 9.5 Gy (LD70/30 for RCBI) whole‐body bilateral 60Co gamma‐photon radiation (0.4 Gy/min), followed by dorsal skin burn injury under anesthesia (∼15% total‐body‐surface area burn). Mice were injected (S.C.) with ODSH (25 mg/kg every 12 h; days 1‐2 and 17.5 mg/kg every 12 h; days 3‐7) or vehicle for 7 days post‐injury and further administered topical gentamicin (0.1% cream; days 1‐10) and oral levofloxacin (100 mg/kg; days 3‐16). Mice were euthanized on day 30 following water consumption, body weight and survival analysis. Our data showed ODSH had no effect on radiation injury (RI)‐induced mortality (45% ODSH vs. 45% VEH; n = 20). Interestingly ODSH treatment significantly reduced survival after RCBI (12% ODSH vs. 41% VEH; n = 22). Furthermore, ODSH did not affect water consumption or body mass after RI or RCBI. ODSH also did not counteract the negative alterations in hematology, splenocytes, or bone marrow cell counts after RI or RCBI. These data illustrate that ODSH in combination with antibiotic treatments, may not be a mitigating countermeasure for RCBI. This work was supported by NIAID Grant G1B2265014.
Fluorescent Labeling of the Carbohydrate Backbone of Peptidoglycan to Track Degradation In Vivo
Authors: Wang Yiben , Leimkuhler‐Grimes Catherine
Published: June 2021

Microbe associated molecular patterns (MAMPs) are detected via Toll‐ and Nod‐like receptors. Upon their activation, inflammatory molecules are produced in cells. One specific example of a MAMP is muramyl dipeptide (MDP), a small fragment of the bacterial cell wall peptidoglycan. Synthetic MDP has been shown to elicit an immune response by activating nucleotide‐binding oligomerization domain‐containing protein 2 (Nod2). However it is still unclear how MDP, with its unusual stereochemistry, is released from the peptidoglycan. Furthermore, it is unknown if there are other peptidoglycan fragments that can activate the innate immune system. The main objective of this study is to investigate the possibility of using peptidoglycan O‐acetyltransferase B (PatB) to fluorescently label the peptidoglycan to track the generation of these immunostimulatory fragments. PatB acetylates the sixth hydroxyl position of N‐acetylmuramic acid (MurNAc), one of the two alternating sugar units of the peptidoglycan backbone, to block the cleavage of the peptidoglycan by lysozyme and other lytic transglycosylases. We aim to hijack this modification pathway to fluorescently label the peptidoglycan. To this end, we optimized the expression and purification of PatB. Initial in vitro studies using PatB and tri‐N‐acetylglucosamine (GlcNAc)3, the other sugar unit, as the acceptor shows that we are able to install a variety of functional groups, including an alkyl derivative, at the sixth hydroxyl group. The alkyl handle will allow for fluorescent labeling of the peptidoglycan through Click chemistry. We are currently working towards observing the degradation of fluorescently labeled peptidoglycan in vivo.

Funding for this project has been provided by NIH COBRE grants and the NIH‐CBI T32 Training Grant.
Molecular Screening for Antagonists of HIV‐1 Viral Infectivity Factor Enables Drug Discovery
Authors: Salter Jason , Bennett Ryan , Morales Guillermo , Smith Harold
Published: June 2021

HIV‐1 Viral infectivity factor (Vif) is a viral accessory protein that is absolutely required for HIV‐1 infection in CD4+ T cells, macrophages and dendritic cells due largely to its role in recruiting antiretroviral factors of the APOBEC3 family to an E3 ligase complex for polyubiquitination and proteasomal degradation. Oligomerization of Vif is essential for APOBEC3G degradation and for the HIV‐1 life‐cycle but the mechanism of action and molecular oligomeric interface are unknown.

Vif oligomerization is mediated by a conserved 161PPLP164 motif, but the crystal structure of Vif (PDB 4N9F) revealed the burial of the PPLP motif between N and C‐terminal domains. The sole Vif‐Vif crystal contact involves the conserved 40YRHHY44 motif, potentially implicating its involvement in a biological Vif oligomeric interface. The YRHHY motif is also essential for A3G degradation. Thus, inhibition of Vif‐dependent A3G degradation and HIV infectivity by PPLP peptidomimetics may be allosteric. OyaGen has identified a small molecule Vif dimerization antagonist through a novel in‐cell HTS quenched‐FRET assay. Here we show that this hit, BRD25, disrupts Vif oligomerization, reduces APOBEC3G degradation, and decreases HIV infectivity. Fluorescence anisotropy was used to show that BRD25 reduces the size of purified Vif in a dose‐dependent manner, consistent with oligomer disruption. In silico docking of BRD25 with the crystal structure of Vif reveals a potential binding site consistent with its role in disruption of Vif oligomerization and A3G degradation. These data demonstrate the availability of protein‐protein interactions as novel drug targets in HIV infected cells.
Role of the U2AF Homology Motif in Human Tat‐SF1 as a Cofactor for HIV‐1 Splicing
Authors: Loerch Sarah , Kielkopf Clara
Published: June 2021

The HIV‐1 life cycle relies on controlled ratios of unspliced and alternatively spliced mRNAs. Human Tat‐SF1 is a requisite host factor for the regulation of HIV‐1 RNA splicing. It is known that Tat‐SF1 associates with the U2 small nuclear ribonucloprotein particle (snRNP) of the spliceosome. However, the underlying mechanisms by which Tat‐SF1 affects HIV‐1 RNA splicing remain elusive.

The core U2 snRNP protein subunit SF3b155 comprises five tryptophan‐containing motifs, termed U2AF ligand motifs (ULM) interspersed with regulated phosphorylation sites. Our lab has shown previously that the SF3b155 ULMs are recognized by splicing factors containing a small globular domain named U2AF homology motif (UHM). Based on sequence homology, we identified a putative UHM in Tat‐SF1. We hypothesize that this UHM provides a phosphorylation‐sensitive link between this alternative splicing factor and the splicing machinery via SF3b155.

To investigate the Tat‐SF1 UHM interactions with SF3b155 and the role of phosphorylation, we determined the crystal structures of the Tat‐SF1 UHM in complex with a minimal phosphorylated SF3b155 ULM and for comparison the unphosphorylated and apo‐forms at 1.7 Å, 1.9 Å, and 1.1 Å, respectively. The apo‐Tat‐SF1 UHM displays a canonical UHM‐fold. The complex with the phosphorylated ULM reveals that the phosphorylation site is located closely above the plane of an aromatic residue. This suggests a reduced affinity of phosphorylated SF3b155 for the UHM due to electrostatic repulsion between the phosphate‐anion and the π‐cloud of the aromatic side chain. We are currently testing the phosphorylation‐sensitivity and significance of these Tat‐SF1 UHM/SF3b155 ULM‐interactions for HIV‐1 infectivity in vivo.
Effect of Curcumin and Silymarin in Combination Exerts Synergistic Inhibition of Colon Cancer Cell Proliferation
Authors: Montgomery Amanda , Daniel Nalini , Ezekiel Uthayashanker
Published: June 2021

Consumption of a diet rich in phytochemicals is efficacious in inhibiting colon cancer. Curcumin is the major component of the spice turmeric, and silymarin, the bioactive component of milk thistle, is used as a supplement for liver disease. We studied the antiproliferative effect of curcumin alone and silymarin alone or the combination of curcumin and silymarin using the colon cancer cell lines DLD‐1, HCT116 and LoVo. Curcumin inhibited colon cancer cell proliferation in a concentration dependent manner, whereas silymarin showed significant inhibition only at the highest concentration assessed. We found synergistic effects when curcumin was held at a constant concentration (12.5 µM) and the silymarin concentration was varied. Pre‐exposure studies were conducted using DLD‐1 cells with curcumin alone followed by different concentrations of silymarin or silymarin alone followed by different concentrations of curcumin. Results indicated that curcumin sensitized silymarin effect whereas silymarin did not sensitize curcumin effect. The outcome of this research study shows that combinations of phytochemicals could prevent or eliminate colon cancer initiation and/or progression.

AM is supported by DeNardo Foundation Fellowship.
Characterization of the role of noradrenaline in brain vs adrenaline in blood reveals a metabolic psychosomatic axis
Authors: Bennun Alfred
Published: June 2021

Sensorial neurons activate the neurons of locus coeruleus with long axons that presynaptically release noradrenaline (NA) at almost all brain areas, stimulating postsynaptically adenylyl cyclase (AC). The enzyme at the cortex, striatum, hypothalamus, and other regions could be synchronized into simultaneous perception scenery, in which Mg2+ is required for activatory and Ca2+ for inhibitory AC‐coupling with the NA‐receptor. Alternation of Mg2+ activation with Ca2+ inhibition of the a2‐adrenergic receptor could code pulsatile generation of cAMP. Fear, danger or decreased level of glucose signals for a stress turn‐on of the hypothalamic‐pituitary‐adrenal (HTPA) axis to drive the psychosomatic fight‐or‐flight response. The adrenal gland releases adrenaline to stimulate AC‐dependent lipolysis and cortisol‐dependent release amino acids. The effect activates an out of circadian control gluconeogenesis. The blood‐brain barrier (BBB) does not allow a negative feedback of adrenaline to turn‐off the overstimulation on HTPA. This empowers a brain for the fight‐or‐flight signaling to overcome tendency of physiological return optimizing survival by restricting anxiety, fear, anger, etc., into the unconscious psyches. Evolution appears to have connected perception with emotional response into a survival efficient emotional memory and intelligence. This role of the adrenergic system has a disadvantage the high vulnerability of humans to stress and related diseases. Increased social pressures are raising environmental anxiety, which requires that in addition to psychological treatment of individuals there is a need for protective policies directed to decrease stress.
All‐atom Folding Simulations of Insulin B‐chain and its Mimetic Peptide
Authors: Mohammadiarani Hossein , Vashisth Harish
Published: June 2021

Insulin is a small peptide hormone that regulates blood glucose levels in higher organisms and thereby plays a central role in diabetes. Novel therapeutic efforts are currently underway to treat diabetes such as design of small synthetic peptides that can mimic effects of insulin binding to the insulin receptor, a cell‐surface glycoprotein of the the receptor tyrosine kinase superfamily. Although many mimetic peptide sequences have been discovered, and found to selectively function as agonists or antagonists, underlying mechanistic details as well as the structures of peptides remain elusive. In this work, we have studied the folding properties and structure of a peptide that mimics the B‐chain of insulin. Using atomistic simulation approaches involving enhanced sampling of peptide conformations, we characterize the folding thermodynamics of mimetic peptide and compare it against folding of the native peptide sequence, the structure for which is known. We observe that the native and mimetic peptides largely show similar folding behavior including underlying thermodynamic details, but various metastable states in each peptide differ. We predict a helical fold for mimetic sequence, similar to insulin B‐chain, and speculate that the stable conformation of mimetic peptide potentially engages receptor via a mechanism similar to the native hormone.
Loss of agr Quorum Sensing and Virulence Function Leads to Early Growth Advantage in Staphylococcus aureus Infection
Authors: Winnett Alex , Femling Jon
Published: June 2021

Staphylococcus aureus antibiotics‐resistant infections present frequently to the Emergency Department, regularly causing significant tissue damage and fatal systemic bacteremia. Previous studies show that agr quorum sensing is an important virulence regulation pathway that mediates hundreds of genes enhancing infectivity and exacerbating disease. However, natural agr‐deletion mutants (Δagr) have been isolated from hospitalized patients, suggesting that the loss of agr may have a selection advantage in some situations. We hypothesize that agr mutants will have a competitive growth advantage in immunocompromised patients compared to agr‐competent strains. We have isolated bacteria from patient abscess fluid and measured competitive growth of each strain after joint exposure to freshly isolated normal or antimicrobial‐defense inhibited neutrophils. In addition, the effect of pharmacological inhibition (via a small molecule inhibitor of the agr receptor, Savirin) of the agr system on strain viability has been analyzed. We have confirmed that natural genetic Δagr strain infection as well as Wild Type Savirin‐induced agr knockout bacteria cause less neutrophil lysis, and show that there is a decrease in bacterial killing in both agr‐inhibited conditions during the first 30 minutes. This suggests that the regulation of bacterial virulence by agr quorum sensing has a complex effect on the survival of Staphylococcus aureus bacteria during the initial interaction with host immune system defenses.
The Mediating Effect of Zinc on the Association between Vitamin D and Hemoglobin Status in Kenyan Preschool Children
Authors: Houghton Lisa , Bailey Karl , Harper Michelle , Beaumont Sarah , Brown Rachel , Erhardt Jürgen , Kung'u Martin , Bautista Maria , Gibson Rosalind
Published: June 2021

In some cases, zinc deficiency has been associated with increased risk for anemia while a growing body of evidence suggests that vitamin D also plays a role in anemia, although the mechanism is unknown. This study investigated the association of serum 25‐hydroxyvitamin D (25OHD) with hemoglobin (Hb) levels and anemia, and tested whether zinc status was a mediating factor in the association between 25OHD and Hb. We used data on 485 children aged 2‐5 y collected in a cross‐sectional survey in southeastern Kenya. Nearly 20% of the children were anemic, 39% were zinc deficient and 25OHD ranged from 47 to 171 nmol/L. After controlling for other factors that may contribute to anemia including age, sex, inflammation and iron deficiency, higher 25OHD levels were associated with decreased risk for anemia (OR 0.977, 95% CI 0.956, 0.997, P=0.02). To examine the extent to which zinc mediates the association between 25OHD and Hb, univariate regression models controlling for all relevant covariates showed there were positive associations between 25OHD and Hb (P=0.03), 25OHD and zinc (P<0.001), and zinc and Hb (P<0.01). With Hb as the dependent variable, including both 25OHD and zinc in a multivariate model rendered 25OHD nonsignificant (P=0.09), whereas the relation between zinc and Hb remained (P=0.01). Sobel‐Goodman test indicated zinc mediated 21% of the total effect of 25OHD on Hb suggesting that vitamin D and the mechanism by which it affects Hb are contingent upon zinc status. Funded by NZ Ministry of Foreign Affairs & Trade.
Breast Milk Iodine Concentration Correlated with Urinary Iodine Concentration of Infants from Southern Ethiopia
Authors: Gebreegziabher Tafere , Stoecker Barbara
Published: June 2021

Breast milk from iodine‐sufficient mothers is considered an adequate source of iodine for the exclusively breastfed infant until the age of 6 months. A national policy requiring salt iodization was initiated in Ethiopia in 2011, but reports indicate high variability in salt iodine concentration (SIC) at the community level. Although the recommended household SIC should be 15‐40 ppm, salt from 102 rural households of lactating women in southern Ethiopia ranged from 0 to 39 ppm. Only about 20% of households had SIC >15 ppm. Mean ± SD age of mothers was 23 ± 3.9 y. Maternal BMI was 21.3 ± 2.5 and MUAC was 23.1 ± 1.9 cm. Goiter was observed in 75 of the mothers. Breast milk and urine samples were collected from these mothers and urine samples were collected from their 6 day old infants. Breast milk iodine (BMIC) and urinary iodine (UIC) were analyzed by inductively coupled plasma mass spectrometry (ICP‐MS). Median (Interquartile range) BMIC was 1551 (495, 2487) µg/L. Median maternal UIC was 106 (71, 160), but 47 had UIC below 100 µg/L. Median infant UIC was 212 (109, 348) µg/L. UIC of the mother correlated with BMIC (r=0.26, p< 0.007). BMIC and infant UIC were correlated (r=.34, p<0.0001) as were UIC of mother and infant (r=.63, p <0.0001). UIC of the mother and iodine of the household salt predicted 15% of the variation in BMIC while UIC of the mother and BMIC predicted 41% of the variability in UIC of the infant. Despite the fact that the study population was getting variable amounts of iodine from the recently implemented salt iodization program, BMIC at 6 days after delivery was high. (Supported by Néstle Foundation and Oklahoma Agricultural Experiment Station).
Online Social Media to Deliver Nutrition and Physical Activity to Adolescents in Maine
Authors: Camire Mary , Lemire Deniele , White Adrienne , L'Italien Matthew
Published: June 2021

Maine adolescents may face barriers to eating well and exercising outside of school due the long winters and lack of public transportation. Internet access is readily available however. The objective of this study was to identify messages on social media that would appeal to Maine youth aged 14‐18 years. Nine 90‐minute focus groups (average n=5) were held. Teens also completed a 10‐item questionnaire. The focus group script was pilot‐tested, and the focus group were videotaped, then transcribed. Questions1‐5 and 11‐14 were tallied; questions 6‐10 were analyzed by the grounded theory approach to qualitative analysis. Teens preferred informal, Internet‐based messages, particularly on Facebook. The top three motivators for change were self‐esteem, attractiveness to the opposite gender, and athletic performance. Study participants identified several ways in which they would like to take more control of their health, such as packing their own lunches. The teens indicated that messages delivered by well‐known athletes, or other celebrities, would be better received among teens. The study is limited in that participants self‐selected to join, that Maine is a largely Caucasian state, and that not all Maine communities were interviewed. However, the findings indicate that strides forward in adolescent health could be made, particularly in Maine's Franco‐American population.
Eating Habits and Patterns of Female College Athletes
Authors: Markovic Srdan , Phelps Josh , Crook Tina , Hakkak Reza
Published: June 2021

The benefit of adequate nutrition contributing to successful athletic performance is well known, but not completely understood and applied among athletes. The purpose of this study was to assess nutrient intakes, and dietary habits and patterns of female college athletes by comparing participant data to sports nutrition recommendations for athletes. Participants (n = 49) completed a Nutritional Questionnaire followed by a detailed 3‐day food record. Overall energy consumption and macronutrient distributions were measured; data were also collected on participants' eating habits. Mean carbohydrate intake (3.8g/kg/day + 1.54) was significantly lower than the minimum recommendation for athletes (5g/kg/day of body weight) [t (29) = ‐ 4.237, p < 0.05]; mean protein intake (1.23g/kg/day + 0.49) did not differ from the minimum recommendation for athletes (1.2g/kg/day) [t (29) = .390, p = 0.70]. Frequency analysis showed 73.3% of participants consumed an appropriate amount of fat in line with the Acceptable Macronutrient Distribution Range (AMDR) of 20‐35% of total energy intake. The majority of participants (77%; 37/48), thought of themselves as being at a healthy weight range; however, 54% (20/37) of these participants expressed the desire to lose weight or to decrease body fat. A paired sample t‐test showed mean total energy intake (1860 kcal + 748.7) was significantly lower than mean total energy expenditure (3130 kcal + 340.3) [t (29) = 9.293, p < .05], with 90% of participants reporting lower than required energy intake. Lack of adequate energy intake presents problems among athletes, not only pertaining to performance, but regarding general health as well. There is a great need for nutritional education among this particular population.
The Majority of Athletes Participating in Winter Multisport Events and Ironman Fail to Meet Recommended Intakes for Endurance Sports
Authors: Masson Genevieve , Lamarche Benoit
Published: June 2021

Participating in endurance sports requires optimal nutrition, with particular focus on dietary carbohydrates (CHO). Yet, little is known regarding dietary intakes of athletes involved in multisport endurance events. The objective of this observational study was to evaluate the nutritional habits of non‐elite athletes participating in winter triathlon (snowshoeing, skating and cross‐country skiing), winter pentathlon (winter triathlon sports + cycling and running), Ironman (IM‐ swimming, cycling, running) and half‐distance Ironman (IM70.3). A total of 151 athletes (44 women and 107 men) competing in a winter triathlon, winter pentathlon or in one of the IM and IM70.3 events were included in the analysis. Participants completed an online validated food frequency questionnaire. Other questionnaires assessing training habits, socio‐demographic information and sport food and supplements use were also completed. Athletes (21‐66 years) trained on average (±SD) 11.8±1.7 hours per week. Average energy intake was 3257±1091 kcal with higher energy intakes (p<0.001) reported by IM athletes compared to other groups. A significantly higher proportion of men achieved the recommended intakes of proteins (1.6 g/kg of body weight) compared with women (72.0 vs. 54.6%, p=0.04). On the other hand, small proportions of both men (37.4%) and women (27.3%, p=0.24 for difference between gender) meet the recommended CHO intakes for endurance athletes (7g/kg of body weight). Our data suggest that a majority of athletes involved in endurance multisport events fail to reach the minimal recommended intakes for CHO, highlighting the need for targeted education in this area.

Funding:

Natural Sciences and Engineering Research Council of Canada
Post‐Prandial Changes in Bone Turnover after High Saturated Fat Challenge Meals
Authors: Rogers Tara , Demmer Elieke , Rivera Nancy , Gertz Erik , Zivkovic Angela , Smilowitz Jennifer , German J , Van Loan Marta
Published: June 2021

Biomarkers of bone turnover fluctuate over the course of a day; these fluctuations are exaggerated with food intake. The effect of foods with differing fatty acid profiles on this phenomenon is unknown. We compared bovine milk saturated fatty acids (SFA) to plant‐based SFA on post‐prandial bone metabolism in overweight/obese subjects. Adult subjects (n=20) participated in a randomized controlled trial, consuming 2 isocaloric high fat meals (dairy cheese sandwich vs. vegan sandwich plus palm oil) separated by a 1‐2 week washout period. Blood samples were collected at baseline, 1, 3, and 6 hrs post‐prandial. Bone resorption marker C‐terminal telopeptide of type 1 collagen (CTx) and bone formation marker cross‐linked C‐telopeptide of type 1 collagen (C1CP) were measured by ELISA. Spearman's Correlation analyses showed that C1CP and CTx were significantly correlated at baseline for both treatments (dairy: rs=0.585, p=0.007; palm oil: rs=0.630, p=0.003). These correlations remained significant at all time points for palm oil, but not dairy, suggesting a potentially more potent effect of dairy SFA. However, ANOVA revealed no significant effects of time or treatment on C1CP. CTx significantly decreased from baseline to 3 hrs after both dairy (p<0.0001) and palm oil (p<0.01), but there was no significant treatment effect. Differences in SFA composition between dairy and palm oil did not affect the postprandial response of CTx and C1CP in this study.

Funding:

National Dairy Council
THE EFFECT OF CONSUMPTION OF FAT‐FREE DAIRY PRODUCTS OVER EIGHT WEEKS ON BODY WEIGHT, WAIST CIRCUMFERENCE AND SATIETY HORMONES IN OVERWEIGHT AND OBESE INDIVIDUALS
Authors: El Khoury Dalia , Huot Pedro , Barkhordari Nazanin , Smith Chris , Wad Mukta , Goff H Douglas , Anderson G Harvey
Published: June 2021

Increasing dairy consumption may be an alternative to weight loss diets. Therefore, we compared the effects of adding 4 servings per day of fat‐free and low‐fat dairy products to an energy restricted (ER, 500 kcal) diet over 8 weeks on body weight, waist circumference and satiety hormones in overweight/obese individuals. 36 overweight/obese men and women (age: 46±1.19 years; BMI: 30.4±0.46 kg/m2) completed the study. By week 8, all participants reduced weight (‐1.13±0.38 kg; P<0.01) and waist circumference (‐0.70±0.19 cm; P=0.001). Consumption of dairy reduced fasting levels of HbA1c compared with the ER group at week 4 (P=0.006) and week 8 (P=0.065). Furthermore, in women, dairy (32.1±2.8 ng/ml; n=10) led to higher fasting leptin levels than ER diet (23.1±2.0 ng/ml; n=11) at week 8 (P=0.016). By week 8, mean fasting PYY increased in the dairy group (4.06±5.76 pg/ml; n=12), whereas it decreased in the ER group (‐9.19±3.06 pg/ml; n=10) from baseline (P=0.07). There were no differences in glucose area under the curve (AUC) (P=0.33) between the dairy (226±24 mmol/l; n=16) and the ER group (266±33 mmol/l; n=14), and no differences in insulin AUC (dairy: 3735±693 μIU/ml; n=17; ER: 2212±487 μIU/ml; n=15; P=0.09), at week 8. Ghrelin levels were not affected by diet over the 8 weeks. Adding fat‐free and low‐fat dairy products reduced body weight and waist circumference similar to the ER diet but had mixed effects on metabolic measures.

Supported by Natural Sciences and Engineering Research Council of Canada‐Collaborative Research and Development Grant, Dairy Farmers of Ontario and Kraft Canada Inc.
Double Sampling with Multiple Imputation to Answer Large Sample Meta‐Research Questions: Introduction and Illustration by Evaluating Adherence to Two Simple CONSORT Guidelines
Authors: Capers Patrice , Brown Andrew , Dawson John , Allison David
Published: June 2021

BACKGROUND

High throughput meta‐research methods have made large meta‐research questions feasible, possibly at the cost of accuracy. We predict that double sampling with multiple imputation (DS+MI) will result in a precise and accurate estimate of adherence to CONSORT title and abstract guidelines.

METHODS:

We retrieved all PubMed entries with filters: RCT; human; abstract available; and English (n=322,107). We evaluated these with a lower rigor, higher throughput (RLOTHI) search heuristics method. We evaluated a subsample of 500 entries and evaluated them using a higher rigor, lower throughput (RHITLO) human rating method. RHITLO evaluations for the large sample were estimated with multiple imputation.

RESULTS:

The RHITLO and RLOTHI methods in the subsample agreed (phi coefficients: title=1.00, abstract=0.92). Compliance has increased over time, with non‐US countries improving more rapidly. DS+MI logistic regression estimates were more precise than subsample estimates (e.g., 95% CI for change in title and abstract compliance by Year: subsample RHITLO 1.050‐1.174 vs. DS+MI 1.082‐1.151). As evidence of improved accuracy, DS+MI coefficient estimates were closer to RHITLO than the large sample RLOTHI.

CONCLUSIONS

Our results support our hypothesis that DS+MI improves precision and accuracy. This method is flexible and may provide a practical way to examine large corpora of literature.

Support:

NIH grants K12GM088010, P30DK056336, T32HL072757, and R25HL124208.
Validity of Food Frequency Questionnaire may be improved by Factoring Gender in Development Stage
Authors: Lee Hanna , Shim Jae eun , Paik Hee young
Published: June 2021

Although men and women differ in their preferences of food items and amount of consumption, these differences have rarely been reflected in developing food frequency questionnaires (FFQs). This study was conducted to investigate whether the results of FFQ validation studies are influenced by factoring gender in development stage. Searching in PubMed with combinations of keywords “FFQ,” “Food frequency questionnaire,” “Validation,” and “Validity” yielded a total of 1,124 articles. Excluded were studies conducted in one sex or with subjects other than healthy adults, review articles, articles published in languages other than English, and articles that could not be found through web searches. The remaining 246 validation studies were divided into two groups: (1) gender‐factored (GF) group which used FFQs developed with consideration of gender differences, and (2) not gender‐factored (NGF) group which used FFQs with no gender consideration. Differences between FFQ and reference methods in estimated intake levels of eight nutrients ‐ energy, carbohydrate, protein, fat, cholesterol, fiber, vitamin C, and calcium – were compared between the two groups. Intake levels estimated by FFQ were more close to those of reference methods in GF group than NGF group in six of the eight nutrients in total subjects. The influence tended to be greater in women (five nutrients) than in men (two nutrients). These results indicate the validity of the FFQ can be improved, especially in women, by incorporating gender differences in the development stage of FFQs. More studies are needed to confirm whether GF FFQs are more sensitive in detecting diet‐disease relationship compared to NGF FFQs.
Changes in Dietary Intake Among Participants in a University Worksite Wellness Program (WWP) Using the Dietary Screening Questionnaire (DSQ)
Authors: Radler Diane , Marcus Andrea , Patel Jay , Griehs Rachel , Touger‐Decker Riva
Published: June 2021

The DSQ is a self‐administered on‐line 26‐item assessment of dietary intake over the past month. Participants who enrolled in the WWP between October 2013 and August 2014 completed the DSQ at baseline and after one‐on‐one counseling and a 12‐week education intervention. Comparison analyses were completed among those participants who provided sufficient responses to estimate intake for both time points for each food/nutrient. Paired t‐tests were used to evaluate significant changes (p<0.05). Results: The mean age of participants who completed the baseline and 12‐week DSQ (n=48) was 44.93 years; 89.58 % (n=43) were female. Fiber and whole grain intake improved significantly; sugar and sugar sweetened beverages intake decreased significantly (p<0.05) after 12 weeks.

Baseline
Follow‐up (12 week)
Comparison

Food/Nutrient
n
Mean
SE
Mean
SE
Change
p‐value

Fiber (g)
35
14.14
0.51
15.47
0.73
1.33
0.040

Calcium (mg)
35
702.90
36.98
717.86
44.16
14.96
0.616

Sugar (tsp)
38
12.67
0.94
10.27
0.69
‐2.39
0.008

Whole Grain (oz)
41
0.78
0.16
1.19
0.22
0.42
0.013

Dairy (cup)
43
1.20
0.08
1.29
0.13
0.09
0.499

Fruit&Vegetable (cup)
39
2.70
0.14
2.88
0.17
0.18
0.202

Fruit&Vegetable no FF (cup)
39
2.65
0.14
2.84
0.16
0.20
0.168

SSB (tsp)
44
4.31
0.76
2.81
0.45
‐1.50
0.011

Key: g=grams, mg=milligrams, tsp=teaspoon, oz=ounce, FF=French Fries, SSB=sugar sweetened beverage; bold=statistically significant change (paired samples t‐test)

Conclusions

Among participants in a WWP who completed the DSQ at baseline and after 12 weeks, significant improvements were seen in dietary intake that reflect changes in reported food consumption. Funding source: Internal Grant and Healthcare Foundation of New Jersey
Dietary Fiber Intake and Cardiometabolic Conditions among Adult Survivors of Childhood Cancer: A Report from the St. Jude Lifetime Cohort Study
Authors: Jia Yinan , Zhang Fang Fang , Ojha Rohit , Lanctot Jennifer , Chemaitilly Wassim , Krull Kevin , Hudson Melissa
Published: June 2021

Background

Childhood cancer survivors experience high risk of dyslipidemia, insulin resistance, hypertension, and obesity in young adulthood. A high‐fiber diet is associated with reduced risk of cardiometabolic conditions but it remains unclear whether such a diet can decrease cardiometabolic morbidity in childhood cancer survivors.

Methods:

For 2,571 young adult survivors of childhood cancer (mean ± SD for age = 32.6 ±8.3 years) in the St. Jude Lifetime Cohort Study, self‐reported dietary intake was assessed using the Block food frequency questionnaire. Systematic medical assessments included measurements of blood pressure, weight, height, waist circumference, serum fasting lipids, glucose, and insulin. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) after adjusting for age, sex, race/ethnicity, family income, total energy intake, physical activity, smoking, alcohol consumption, and dietary patterns.

Results:

The mean dietary intake of fiber was 8.5 g/day per 1,000 kcal calories, substantially lower than the recommended intake(14 g/day per 1,000 calories). Compared to survivors in the lowest quartile of fiber intake, those in the highest quartile had 30‐40% lower odds of prevalent dyslipidemia (OR=0.69, 95%CI: 0.51‐0.95, Ptrend=0.02), hypertension (OR=0.65, 95%CI: 0.47‐0.90, Ptrend=0.007), insulin resistance (OR=0.62, 95%CI: 0.45‐0.85, Ptrend=0.006), and metabolic syndrome (OR=0.61, 95%CI: 0.42‐0.87, Ptrend=0.03).

Conclusions

High dietary intake of fiber was inversely associated with the prevalence of cardiometabolic conditions among young adult survivors of childhood cancer.