bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examining causes and contributors to falls in Parkinson disease (728.9)
Authors: Smith Lorinda , Hunt MaryEllen , Dibble Lee , Merryweather Andrew , Foreman K 
Published: June 2021

The high incidence of falls in people with Parkinson disease (PPD) (>70% fall each year, 13% fall > once/week) is attributed to central nervous system damage that disturbs movement amplitude regulation and sensory processing. Despite this, PPD are capable of learning motor tasks with practice. Virtual environments are being developed to provide safe repetitive practice in an effort to decrease falls. To inform the development of these environments, we examined causes and contributors to falls from the perspective of PPD. Eleven men with mild to moderate PD completed a semi‐structured, mixed methods interview. Subjects rated environments on a scale from 1 (never difficult to walk or maintain balance) to 5 (always difficult), and descriptive statistics were calculated. They answered open‐ended questions about mobility and falls, and coding was used to categorize this data. The most difficult surface type was “Unreliable/Unstable” (e.g. loose gravel, mean=3.64), followed by “Irregular/Inconsistent” (e.g. cobblestones, mean=3.09) and “Angled” (mean=3.09). “Visual Factors” (e.g. glare, mean=3.09) were rated similarly. Multitasking and feeling rushed or worried were identified in open‐ended responses as common contributors to falls in the “Distracting” category (mean=2.91). “Obstacles” were rated as moderately difficult (mean =2.22), but were identified as a frequent concern and contributor to falls when fall history was examined. The most challenging scenarios combined several of these factors. With this knowledge, virtual environments that allow for motor learning through safe practice of challenging scenarios are being created. Future research is necessary to determine to what extent this virtual‐based learning will transfer to real‐world scenarios, and the dosage of practice necessary to achieve a functional decrease in falls in PPD.Grant Funding Source: Supported by NSF 1162131
Gene control using tRNA‐shRNA chimeras: knockdown by shRNA and degradation of tRNA (749.3)
Authors: Zazueta Christopher , Stork Devon , Haushalter Karl 
Published: June 2021

Gene therapy using RNA interference (RNAi) mediated by short hairpin RNAs (shRNAs) targeted against HIV‐1 is a promising alternative to antiretroviral therapy. Fusing shRNA to carrier tRNA to produce a tRNA‐shRNA chimera can provide a tunable level of shRNA delivery that is dependent on the action of the enzyme tRNaseZ to separate the shRNA and tRNA components of the chimera. We have introduced changes in the sequence of the acceptor stem of the tRNA portion of the tRNA‐shRNA chimera to produce the next‐generation of tRNA‐shRNA chimeras. Our targeted mutations are designed to result in an isomerization that triggers rapid tRNA decay after release of the shRNA by tRNaseZ. The knockdown efficiency of the resulting constructs can be assayed by a dual luciferase assay.Grant Funding Source: Supported by NSF CHE‐1005253
Aminotransferase activity of a novel aminoacyl‐tRNA synthetase appended domain (751.3)
Authors: Sharma Sandhya , Alexander Rebecca 
Published: June 2021

Aminoacyl‐tRNA synthetases (AARSs) are key enzymes in protein biosynthesis, responsible for attaching amino acids to the 3ʹ‐end of cognate tRNAs. The AARSs are modular proteins, with separate polypeptide domains responsible for tRNA binding and catalysis; additional domains on some AARSs contribute oligomerization, localization, and editing functions. The opportunistic pathogen Mycoplasms penetrans expresses an unusually long version of methionyl‐tRNA synthetase (MetRS) that contains an extra N‐terminal domain with sequence homology to class V aminotransferases. We anticipated that this domain carries out pyridoxal phosphate (PLP)‐dependent aminotransferase activity, possibly to modify Met‐tRNA(Met) for enhanced pathogenicity.We overexpressed and purified M. penetrans MetRS (MpMetRS) and used the amino‐reactive aromatic dialdehyde naphthalene‐2,3‐dicarboxaldehyde followed by HPLC to analyze enzyme activity in vitro. Initial characterization confirms the proposed aminotransferase activity, with several amino acids and α‐keto acids serving as amino group donors and acceptors, respectively. Substitution of amino acids in the transferase and synthetase catalytic sites indicate that these activities are independent. Ultimately we seek to identify the cellular substrates and implications of the MpMetRS aminotransferase activity.Grant Funding Source: Supported by the National Science Foundation
The role of oxyanion holes in the structure and function of type III polyketide synthases (768.18)
Authors: Stewart Charles , Noel Joseph 
Published: June 2021

The objective of this study was to combine the tools of protein crystallography and enzyme kinetics to explore the structural mechanisms of type III polyketide synthases (PKSs). Type III PKSs are proteins involved in diverse metabolic processes including cell signaling, pathogen defense and the development of reproductive cells. Mechanistically, these enzymes generate metabolites through the repetitive addition of acetate units onto a starter molecule; a process that produces reactive intermediates that are ultimately cyclized into the final product. How these enzymes control their reactive intermediates and terminal cyclizations is not fully understood and is a major hindrance to protein engineering efforts. We present here our results describing the role of oxyanion holes in the mechanism of type III PKSs. Crystallographic studies of reaction analogs trapped in the active site revealed that remnants of an ancient oxyanion hole are involved in stabilizing reactive intermediates. Unexpectedly, we observed that a small molecule, metazachlor, has different conformations in the active site of functionally distinct PKSs. Enzyme kinetic studies supported our structural findings by establishing that metazachlor differentially inhibits type III PKSs based on their terminal cyclization steps. These structure‐function studies are being used as a guide for altering the terminal cyclization preferences of type III PKSs to build novel compounds.Grant Funding Source: Supported by Howard Hughes Medical Institute and National Science Foundation
Probing the role of S28 in Thermodesulfovibrio yellowstonii adenonsine diphosphate glucose pyrophosphorylase: insight in to allosteric regulation and sensitivity (769.14)
Authors: Susoeff Michael , Yik Eric , Badal Matthew , Kaur Sandeep , Almendarez Jessica , Almendarez Jessica , Meyer Christopher 
Published: June 2021

Renewable and biodegradable glucans are in demand for use in a variety of industries. Adenosine Diphosphate Glucose Pyrophosphorylase (ADPG PPase), an allosterically regulated enzyme, serves as the rate limiting step in glucan biosynthesis and is an attractive target for protein engineering to increase yield. The enzyme from Thermodesulfovibrio yellowstonii (Td.y) has been successfully expressed in E. coli and a purification scheme that includes hydroxyapatite and anion exchange chromatography optimized. The inclusion of 250 mM NaCl in the running and storage buffers increased the yield and solubility (over 20 mg/mL) of the enzyme. The Td.y ADPG PPase contains a primary sequence that deviates from consensus in the conserved KRAKPAV region (amino acids 23‐29), shown to be important for activity and regulation. To explore its role, the S28A enzyme was generated and characterized with respect to temperature, pH, and kinetic parameters for substrates and effectors. The S28A altered enzyme was found to have the same optimal temperature (70°C) and pH (8.5) as the wild type (WT) enzyme. While the specific activity in the absence of activators was found to be 2‐fold lower than WT, the fold activation response to the allosteric activators, phosphoenolpyruvate, fructose‐1,6‐bisphosphate, glucose‐6‐phosphate, and 3‐phosphoglycerate, was 2‐3 fold higher than WT. Thus position 28 plays a role in sensitivity to allosteric activation. Complete kinetic analyses of the S28A enzyme and other altered proteins are underway, as well as crystallization trials as a first step in solving the three‐dimensional structure.Grant Funding Source: NSF Grant 0448676
Structure‐function studies of the ADPglucose pyrophosphorylase from Thermotoga maritima: probing the role of a conserved aspartate residue in the glgD and glgC subunits (769.20)
Authors: Vu Crystal , Arteaga Adrianna , Jacobs‐Edmonson Raymond , Meyer Christopher 
Published: June 2021

ADPGlucose pyrophosphorylase (ADPG PPase, glgC gene) catalyzes the rate‐limiting step of glucan biosynthesis in plants and bacteria. Structure‐function studies of the diverse forms of the enzyme will allow for the engineering of a more active enzyme to produce more renewable carbon. In Thermotoga maritima (T.ma) there are two genes, glgC and glgD, which code for two subunits of this ADPG PPase. The recombinant His‐tagged subunits were successfully purified using a heat step and nickel chromatography; the wild type (WT) glgD alone had little to no activity, while the glgC protein displayed a specific activity of ~3 Units/mg with S0.5 values for ATP and magnesium (Mg) of 5.4 mM and 18.7 mM, respectively. However, the WT glgC/D complex was stimulated ~5‐fold compared to glgC alone and also activated ~2‐fold by FBP. Previous alignment studies and molecular modeling indicated that glgC D126 plays a role in catalysis so the D126A enzyme was generated to test this hypothesis. The glgC D126A protein displayed a modest increase in apparent affinity for substrates compared to WT but a 25‐fold decrease in Vmax indicating a role in optimal catalysis. Interestingly, the inactive glgD protein also harbors an aspartate (D125) at this position and the D125A glgD enzyme was generated for characterization. Surprisingly, the altered protein was found to have activity with S0.5 values for ATP, Mg, and G1P of 4.90 mM, 14.8 mM, and 39.2 µM, respectively, with a Vmax of 0.26 U/mg. In preliminary assays, we found that the glgD D125A/glgC complex displayed only a small stimulation compared to glgC alone while the glgD/glgC D126A complex displayed stimulation comparable to WT; a very large stimulation of activity was found when the glgD D125A/glgC D126A was combined, rising to the level of the glgD D125A/glgC2 complex. These aspartate residues may affect activity and stimulation of the subunits in a complex in a synergistic manner. Complete kinetic and physical characterization of the altered enzyme complexes is underway.Grant Funding Source: Supported by NSF award 0448676.
Maternal anemia, iron deficiency, and pregnancy outcomes in India (804.10)
Authors: Finkelstein Julia , Duggan Christopher , Thomas Tinku , Bose Beena , Samuel Tinu , Srinivasan Krishnamachari , Kurpad Anura 
Published: June 2021

Objective: To examine the burden of anemia and iron deficiency and its association with pregnancy outcomes in women in India.Methods: A total of 366 pregnant women who were participating in a vitamin B12 supplementation trial in India were monitored to assess the associations of maternal hematological status during pregnancy (hemoglobin, ferritin, CRP, AGP) and birth outcomes. Binomial and linear regression models were used to evaluate the associations between maternal iron status and pregnancy outcomes.Results: Anemia and iron deficiency were common in pregnancy: 30% of women were anemic (Hb<11.0 g/dL), 40% were iron deficient (ferritin<12 µg/L), and 22% had iron deficiency anemia. Maternal anemia predicted 2.4 times greater risk of preterm delivery (p<0.01) and increased risk of low birth weight (p=0.05). Maternal iron deficiency predicted a 2.5‐fold higher risk of preterm delivery (p<0.01), and iron deficiency anemia predicted a three‐fold greater risk of preterm delivery (p<0.001).Conclusions: Anemia, iron deficiency, and iron deficiency anemia are common in pregnant Indian women and are associated with increased risk of adverse pregnancy outcomes.Grant Funding Source: Supported by: NICHD, ICMR, NIHK24; HIGH, SAI, Rose, SJRI, and DNS.
The effect of prenatal multiple micronutrient supplementation on biomarkers of placental angiogenesis in rural Bangladesh (804.2)
Authors: Gernand Alison , Schulze Kerry , Shaikh Saijuddin , Shamim Abu , Ali Hasmot , Wu Lee , West Keith , Christian Parul 
Published: June 2021

Prenatal multiple micronutrient (MM) supplementation improves birth weight through increased gestational age, yet it is unknown if improved placental function contributes to this effect. We assessed the effects of prenatal MM vs. iron and folic acid (IFA) on placental angiogenesis (the formation of blood vessels from existing ones) in a subset of women (n=395) participating in a double blinded, cluster‐randomized trial in rural Bangladesh. Angiogenic factors assessed in maternal plasma at 10 and 32 weeks gestation were placental growth factor (PlGF), angiopoietin 2 (Ang‐2), vascular endothelial growth factor (VEGF), and VEGF receptor 1 (VEGFR‐1). Concentrations were similar at baseline (10 weeks); PlGF, VEGF and VEGFR‐1 increased from the first to third trimester, whereas Ang‐2 decreased in both groups (p<0.01). At 32 weeks, PlGF and Ang‐2 were positively associated with gestational age and placental weight at birth and VEGFR‐1 was positively associated with placental weight (all p<0.05). Ang‐2 was 3.1 (95% CI: 0.20, 6.0) ng/mL higher at 32 weeks in mothers taking MM vs. IFA. There was no difference between MM and IFA groups in other angiogenic factors at 32 weeks, or their change from 10 to 32 weeks. MM supplementation improved angiogenic Ang‐2, reflective of enhanced placental vascular remodeling that may explain part of the MM impact on birth size through increased gestational age.Grant Funding Source: Supported by The Thrasher Research Fund, NIH (T32HD046405), The Gates Foundation, and USAID
National WIC infants and toddlers feeding study (805.15)
Authors: Harrison Gail , McNutt Suzanne , Weinfield Nancy , MacAllum Crystal , Owens Tameka 
Published: June 2021

This is a nationally representative longitudinal study of contemporary feeding practices for the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) (infants and toddlers in low‐income households and deemed at nutritional risk) population. The study is currently in the field (80 sites, 26 states and one territory); all local and state IRB requirements have been met. Over 4000 women and infants are expected to participate fully; recruitment has been very successful (97% of those invited). Eligible women (English‐ and Spanish‐speaking) are invited/ consented at a WIC enrollment visit. Interviews are conducted prenatally (or at enrollment for those enrolling postnatally within three months of delivery), and up to 10 times during the infant’s first two years of postnatal life. The USDA‐developed Automated Multiple Pass Method 24‐hr recall is utilized to collect 24‐hr dietary data for the child at every interview, and the six‐item USDA food security questionnaire is asked at five interviews. The projected database will be the only current large‐sample longitudinal feeding data representative of children of this age living in low‐income households available for informing the 2020 Dietary Guidelines for Americans.Grant Funding Source: USDA #AG‐3198‐B‐1‐0020
Baseline characteristics of a pregnant, primarily African American cohort residing in the Mississippi Delta: Delta Healthy Sprouts (806.7)
Authors: Goodman Melissa , Thomson Jessica , Tussing‐Humphreys Lisa 
Published: June 2021

Inappropriate gestational weight gain (GWG) is associated with adverse maternal and infant outcomes and increased risk for childhood obesity. Interventions designed to optimize maternal GWG may be effective at improving the health of women and their infants. Delta Healthy Sprouts (DHS) is a randomized, controlled, comparative trial testing the efficacy of two Maternal, Infant, and Early Childhood Home Visiting programs on weight status and health behaviors of mothers and their infants residing in the rural Mississippi Delta. We describe baseline demographic, psychosocial, diet, and physical activity (PA) characteristics of this cohort of women early in their 2nd trimester of pregnancy. The majority of participants are single (88%), African American (94%), and obese (56%), with no more than a high school education (53%), and a mean age of 23 (SD=5.3) years. Over one third (38%) screened for mild to major depression and 91% reported low PA. Mean baseline diet and PA related expectations, social support, and self‐efficacy scores were moderately high, while attitude was low. Half (50%) of the participants were primarily responsible for the household food shopping, 35% for meal preparation; although 31% prepared meals at home less than 4 days/week. Results from DHS will determine if a novel, scalable lifestyle intervention can improve the health of women and their infants in this health disparate region.Grant Funding Source: Supported by the USDA Agricultural Research Service.
Effects of KidQuest on body mass index, lean body mass and body fat percentage among children ages 11 to 14 years in Nebraska (808.14)
Authors: Chai Weiwen , Fischer Jean Ann , Takahashi Shinya , Wallinga Melissa , Anderson‐Knott Mindy , Wolf Tovah , Koszewski Wanda 
Published: June 2021

Objective: Promoting healthy eating and physical activity are key to the prevention of childhood obesity which continues to increase in the U.S. Our study examined the changes in body mass index (BMI), total lean body mass (LBM) and total body fat mass (FM)) in children ages 11 to 14 years after receiving a 6‐week nutrition and physical activity curriculum (KidQuest).Methods: KidQuest was implemented in after school programs in Nebraska. BMI, LBM, and FM were measured before and after the program in 42 children who had both parental and youth consents. Paired t‐test was used to assess the baseline and post intervention differences in the above measurements.Results: No significant differences in BMI were observed before and after the intervention. Based on BMI for age percentile, 10% of the children were overweight and 20% were obese at baseline. There were significant increases in LBM after the intervention (pre, 33.1kg, post, 42.0kg, P<0.0001). Decreases in FM were also observed after the program (pre, 15.1kg, post, 13.8kg, P=0.13).Conclusions: Our observations for changes in LBM and possible FM need to be confirmed with a larger sample size.Grant Funding Source: USDA (AFRI) Grant No. 2011‐67002‐30202
Accuracy of food guide and nutrition label use by caretakers in the STRONG Kids cohort (808.17)
Authors: Paige Katie , Wallace Victoria , Teran‐Garcia Margarita , Donovan Sharon 
Published: June 2021

Childhood obesity rates have risen dramatically in recent decades, compelling researchers to analyze the changing environment surrounding this weight gain. Our goal was to assess parent’s knowledge of food guides and nutrition labels. Parents (n=407) of preschoolers (age 3‐5) reported that moms and grandparents were primarily responsible for selecting meals. Overweight parents had 1.86‐times higher odds of having overweight children (95% CI 1.15‐2.99, p=0.01). Parents of children who were overweight (>85th BMI percentile) had a higher average BMI than parents of children who were normal weight (29.6 vs. 26.6 kg/m2; p=0.0001). Parents’ ability to choose healthy foods may be limited by the way nutrition information is presented. On a nutrition fact label, 35% of parents were unable to correctly complete calculations necessary to interpret nutrition facts. Although 56% of parents attained a Bachelor’s degree or higher, only 32.2% could identify the current USDA food guide. Older and less‐educated parents were more likely to choose an incorrect or outdated food guide (p蠄0.05). The release of multiple food guides in recent decades may have led to consumer confusion. Parent inability to identify current guidelines and interpret nutrition labels suggests poor dissemination of these tools. Clinical settings and grocery stores may serve as opportunities for continued education.Grant Funding Source: Funded by the USDA (Hatch 793‐328), I‐CAR, and NIFA (2011‐67001‐30101)
The unseen power of parents: the influence of parent physical activity behaviors and values on preschool children’s PA, sleep, and screentime (808.2)
Authors: Martin‐Biggers Jennifer , Cheng Carolyn , Byrd‐Bredbenner Carol 
Published: June 2021

This study examined parents’ (n=47) role modeling of PA, importance placed on PA, encouragement of child PA, screentime and sleep hours/day, and PA level and their preschool children’s screentime and sleep hours/day and PA level. Parents were 70% white and 66% had college degrees. Parents had neutral role modeling and positive PA importance and encouragement scores (i.e., 2.99+0.73SD, 3.94+0.65SD, 4.25+0.56SD, respectively, on a 5‐point scale). They had 2.86+2.36SD and 6.98+0.89SD screentime and sleep hours/day, and low to moderate PA level. Children got 3.08+2.92SD and 9.67+1.33SD screentime and sleep hours/day, and had moderate to high PA levels. Child PA level was significantly (p<.05) positively correlated with child sleep hours but was not correlated with any parental measure. Parent sleep was inversely correlated with child screentime hours, suggesting that parents who get less sleep permit screentime more. Child screentime hours and parent BMI were positively correlated with parent screentime. Parent encouragement of and importance placed on PA was associated with their own PA level. Parent sleep, screentime, and PA importance/encouragement are related to child obesity risk factors.Grant Funding Source: Supported by USDA, National Institute of Food and Agriculture, Grant Number 2011‐68001‐30170
Major American dietary patterns are related to risk of age‐related macular degeneration (810.2)
Authors: Chiu Chung‐Jung , Chang Min‐Lee , Zhang Fang Fang , Li Tricia , Gensler Gary , Schleicher Molly , Taylor Allen 
Published: June 2021

Objective: We hypothesized that major American dietary patterns and differences in specific nutrient intakes within the context of the patterns are associated with age‐related macular degeneration (AMD) risk.Methods: 8,103 eyes from 4,088 eligible participants were classified into control, early AMD, and advanced AMD. Using 37 food group data collected by a 90‐item food frequency questionnaire, two major dietary patterns, prudent and Western patterns, were identified by factor analysis.Results: For early AMD, the multivariate‐adjusted odds ratio (OR) comparing the highest to lowest quintile of the prudent pattern score was ORE5P=0.74 (95% confidence interval (CI): 0.59‐0.91; Ptrend=0.01), and the OR comparing the highest to lowest quintile of the Western pattern score was ORE5W=1.56 (1.18‐2.06; Ptrend=0.01). For advanced AMD, the ORA5P was 0.38 (0.27‐0.54; Ptrend<0.0001), and the ORA5W was 3.70 (2.31‐5.92; Ptrend<0.0001). Our data also suggested benefit from higher dietary intakes of vitamin C, lutein/zeaxanthin, and beta‐carotene, especially in the context of the Western pattern. In the context of the two major patterns, we did not observe a relationship between intake of vitamin E, zinc, DHA or EPA and AMD risk.Conclusions: This cross‐sectional study indicates that diet plays an important role in the development of AMD and that the risk for AMD can be diminished by eating a prudent diet.Grant Funding Source: Supported by the NIH and the USDA