bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence of impaired vasodilation during exercise in heart failure with preserved ejection fraction (1156.3)
Authors: Lee Joshua , Barrett‐O’Keefe Zachary , Nelson Ashley , Ryan John , Nativi Jose , Richardson Russell , Wray D 
Published: June 2021

Exercise intolerance is a hallmark characteristic of heart failure (HF), which may be related to impaired exercise‐induced vasodilation in the exercising muscle vasculature. While reductions in exercising limb blood flow have been observed in patients with systolic HF no studies, to date, have evaluated vasodilation in HF patients with preserved ejection fraction (HFpEF) during exercise. Thus, in six HFpEF patients (68±8 yrs) and six age‐ and sex‐matched controls (69±9 yrs), arterial pressure (Finapres) and leg blood flow (LBF; ultrasound Doppler) were assessed during knee‐extension exercise at 0, 5, 10, and 15 W. Resting arterial pressure (HFpEF: 98±2 mmHg; controls: 105±16 mmHg) and LBF (HFpEF: 276±57 mL/min; controls: 299±59 mL/min) were similar between groups. Across work rates, arterial pressure was similar between groups, yet LBF was 30‐40% lower in HFpEF compared to controls (1,256±219 vs. 1,791±151, 1,420±206 vs. 2,102±179, 1,666±91 vs. 2,459±417, and 1,745±206 vs. 2,874±206 mL/min, HFpEF vs. controls at 0, 5, 10, and 15 W, respectively). These data indicate that exercise‐induced vasodilation is markedly impaired in HFpEF patients, which likely contributes to exercise intolerance in this patient population.Grant Funding Source: Supported by NIH PO1 HL‐091830 (R.S.R.) VA RR&D E6910R (R.S.R.) AHA 0835209N (D.W.W)
Acute slow‐paced breathing increases periods of sympathetic nervous system quiescence (1170.12)
Authors: Mozer Michael , Fadel Paul , Johnson Christopher , Wallin B , Charkoudian N , Drobish Justin , Joyner Michael , Wehrwein Erica 
Published: June 2021

Slow‐paced breathing is a simple strategy to reduce psychological stress. We tested the hypothesis that slow paced breathing would decrease muscle sympathetic nerve activity (MSNA). Ten young, healthy males were studied. The subjects were instructed to rest supine and breathe normally (baseline) or at six breaths per minute, each for 20 minutes. MSNA was measured (peroneal microneurography) and analyzed 5 minutes into each stage for a steady state measurement. Statistical analysis was completed using one way RM ANOVA and Tukey’s posthoc analysis (reported mean±SEM). Average respiratory rate was 11.9 ± 1.1 breaths/min during baseline and 5.8 ± 0.7 breaths/min during slow‐paced breathing. There was no significant difference from baseline compared to slow paced breathing in MSNA burst frequency (18±2.0 vs 18±2.40 bursts/min), burst incidence (31.2±4.01 vs. 30.4±3.80 bursts/100 heartbeats) or burst area (12.70±2.18 vs 13.02±1.98%). However, there was a change in the pattern of burst firing with a significant increase in quiescent periods between burst clusters during slow paced breathing compared to baseline (6.50±0.61 vs. 3.59±0.41 seconds), which was accompanied by a significant decrease in the number of bursts/cluster (2.9±0.38 vs. 5.6±0.8 bursts). This has physiological relevance since there was a significant decrease in plasma norepinephrine, increase in blood flow, and a reduction in mean arterial pressure during these same periods. These findings indicate that despite no change in burst incidence, slow paced breathing alters the pattern of MSNA firing, which may contribute to favorable cardiovascular changes.Grant Funding Source: Supported by NIH HL‐083947
Hyperglycemia increases prorenin receptor localization at the cell plasma membrane (1173.7)
Authors: Prieto Minolfa , Arita Danielle , Bourgeois Camille , Satou Ryosuke 
Published: June 2021

The prorenin receptor (PRR) elicits intracellular signals linked to tissue fibrosis based upon its capability to bind prorenin at the plasma membrane (PM) which may contribute to nephropathy and microvascular changes in diabetes mellitus (DM). To test the hypothesis that hyperglycemia increases the capability of PRR to bind prorenin by increasing membrane bound PRR to PM in collecting duct cells, we used type 1 DM rats (N=10) induced with a single STZ injection (ip; 200ng/kg) as well as in M‐1 cells to assess PRR trafficking alteration induced by hyperglycemia. After 7‐days induction, STZ‐rats had levels of plasma glucose of 428±13 vs. 138±9 gr/dL and plasma insulin 0.07±0.02 vs. 2.42 ng/mL compared to control rats. By immunoflurescence (IF) studies of the rat kidney section, PRR was mainly localized predominantely on the pical aspect of collecting duct cells in STZ‐rats while in control rats most of PRR immunoreactivity was observed intracellularly. In methanol‐fixed M‐1 cells, PRR was localized mainly to the perinuclear areas in normal glucose (NG; 1g/L glucose + 1 g/L mannitol)‐treated cells. However, in high glucose (HG; 4g/L)‐treated cells, PRR was predominantly localized toward the surface, as it was appreciated in the de‐convoluted images. Although PRR mRNA levels were not different in the collecting ducts of renal medulla between groups; PRR protein levels (37 kDa) were significantly higher in PM extracts from M‐1 cells treated with HG for 5 minutes, 1, and 6 hours (with a maximum peak observed at 1 hour) than in those treated with NG. These data suggest that hyperglycemia induces PRR trafficking alterations of PRR. The effect of hyperglycemia to increase PRR abundance in PM in the collecting duct may be a novel mechanism underlying the increased hypertension seen in the diabetic patients.Grant Funding Source: Supported by NIH‐DSNTR grant
Risk factors for prelacteal feedings in seven Latin America and Caribbean countries: a multilevel analysis (131.7)
Authors: Boccolini Cristiano , Pérez‐Escamilla Rafael 
Published: June 2021

Objectives: Identify risk factors for prelacteal feedings (i.e., offering liquids before milk begins to flow) in the first three days of life in Latin America and the Caribbean (LAC).Methods: The study used secondary data from Demographic and Health Surveys conducted in seven countries (Colombia/2010, Bolivia/2008, Guiana/2009, Haiti/2005, Honduras/2005, Peru/2007 and Dominican Republic/2007). Binomial regression, with random effects at region and country level, tested the influence of potential risk factors on the likelihood of prelacteal feeding. Countries’ data sets were pooled (N=58,056 children).Results: In the first three days of life, mothers gave infant formula (17.9%), tea/infusions (6.4%), milk other than breast milk (5%), and/or other liquids (4.5%) before breast milk began to flow. Prelacteal feeding’s prevalence varied from 17.6% in Guiana to 55% in Dominican Republic. Independent risk factors for prelacteal feeding were: wealth (1.33, 1.24‐1.46), higher maternal educational level (1.46, 1.32‐1.60), cesarean delivery (2.34, 2.28‐2.41). Hospital delivery (vs. home) was associated with a lower likelihood of prelacteal feeding (0.72, 0.64‐0.80).Conclusion: Findings suggest that the prevalence of prelacteal feeding across countries in LAC varies substantially and that socio‐economic and biocultural factors explain some of the variance in prelacteal feeding within LAC countries.Grant Funding Source: Supported by Brazil's National Council for Scientific and Technological Development (CNPq)
Delaying and reducing medication use as a coping mechanism for food insecurity (268.6)
Authors: Herman Dena , Afulani Patience , Harrison Gail , Coleman‐Jensen Alisha 
Published: June 2021

Objective: To determine if food insecure households are more likely to skip, delay or reduce medications to compensate for lack of household resources to purchase food. Methods: We used data from a combined sample of the 2011 and 2012 National Health Interview Survey (n=52,699). We conducted bivariate and logistic regression analyses to examine the association between food security (FS) and medication use; controlling for demographics, lifestyle, BMI, chronic disease, disability, health care coverage and self‐rated health. Sample weights were applied to account for the complex sample design. Results: Seventy eight percent of respondents reported high FS, 8% marginal FS, 6.9% low FS and 6.0% very low FS. Seven percent reported skipping medications; 7.6% used fewer medications; 9.4% delayed filling a prescription; and 20% lowered the dose of medication. Net of other factors the odds of skipping medications increased with increasing severity of food insecurity (OR of 1.67 for marginal FS, 2.86 for low FS and 4.14 for very low FS). The results were similar for delaying or reducing medications. Also women, low income, working part‐time, current smokers, severely obese, no health care coverage, having a chronic disease, functional limitation and poor self‐rated health had higher odds of skipping, delaying or reducing medications. Conclusion: Delayed or reduced medication use may be used as a coping mechanism among the food insecure and could lead to further negative health consequences for those who may already be suffering from chronic disease conditions.Grant Funding Source: Supported by a cooperative agreement with the ERS, Contract#: 58‐4000‐3‐0009
Biofortified orange maize is as efficacious as a vitamin A supplement in Zambian children even on the background of high liver reserves of vitamin A (39.5)
Authors: Gannon Bryan , Kaliwile Chisela , Arscott Sara , Schmaelzle Samantha , Masi Cassim , Chileshe Justin , Tanumihardjo Sherry 
Published: June 2021

Biofortification is an emerging strategy to relieve vitamin A (VA) deficiency. Biofortified (orange) maize contains β‐carotene (βC) and has shown efficacy for VA status in animal models, but has yet to be confirmed in humans. A randomized, placebo‐controlled orange maize efficacy trial was conducted in rural Zambia. The paired 13C‐retinol isotope dilution test, the most accurate and sensitive indirect marker of vitamin A status, was used to measure total body reserves (TBR) of vitamin A before and after a 90‐d intervention period. Treatment arms were white maize with placebo oil (VA‐), white maize with VA oil (VA+), and orange maize with placebo oil (orange). Change in TBR showed a treatment effect (P = 0.011) with VA+ being significantly greater than VA‐, while orange was statistically similar to both (203 ± 386, ‐4.50 ± 208, 109 ± 341 µmol, respectively). However, data were not normally distributed (P < 0.0001), medians were VA‐ 12.6, VA+ 97.8, orange 83.7 µmol, and non‐parametric analysis showed VA+ and orange were statistically similar and different from VA‐. Baseline estimates of liver concentration were 1.13 ± 0.41 µmol/g, with 59% > 1 µmol/g, the current sub‐toxicity cutoff. None were < 0.1 µmol/g. The bioconversion factor was calculated to be 10.4 µg βC:µg retinol using the middle three quintiles of change in TBR from each treatment group. Change in serum retinol showed no treatment effect (P = 0.16). The βC in maize is a very effective vitamin A source when consumed as a staple food and could avoid potential toxicity issues with preformed VA from supplementation or fortification as seen in this population. Further use of stable isotopes should be used to elucidate the VA status of various populations, and serum retinol should be used with caution in setting global health policy.Grant Funding Source: Supported by HarvestPlus and NIH grant T32‐DK007665 (BG)
A small diameter bioactive prosthetic vascular graft with activated protein C (546.9)
Authors: Linderman Shannon , Araya Joel , Pathan Saif , Nelson David , Phaneuf Matthew , Contreras Mauricio 
Published: June 2021

To date, there are no small (less than 5 mm) internal diameter vascular grafts that are FDA approved for clinical use due to high failure rates from thrombosis and increased cell proliferation, conditions that may be improved with use of enhanced bioengineered graft materials. Here we show that long term graft viability and patency can be improved by covalently binding activated protein C (APC) to prosthetic vascular graft surfaces due to APC’s inherent physical properties. Electrospun polyester (Dacron) grafts covalently bound with APC and woven plain Dacron prosthetic graft controls were evaluated in‐vivo in a common carotid artery bypass canine model with and without Plavix treatment. Blood work samples were taken from each canine (n=12) at 14, 30, 44 or 60 days after graft implantation. Explanted grafts were examined macroscopically and histologically. Upon comparison of all time points, APC grafts offered 25‐50% improvement in patency compared to control grafts. Plavix treatment increased patency of APC grafts from 50% to 100% over 60 days, while the control grafts showed no significant improvement in patency with Plavix treatment. Furthermore, histological evaluation showed that APC grafts had partial endothelial cell (EC) coverage of the luminal surface (CD31 positive) in the midd‐portion while the Dacron control grafts did not. At the anastomosis, there were no distinct differences in overall graft healing (SMC‐a, Ki67). Our results suggest that Dacron‐APC grafts not only offer a significant improvement in patency over woven control grafts, but also promote EC healing throughout the luminal surface of the graft. Perhaps longer term studies are needed to asses if partial EC coverage could become complete over time.Grant Funding Source: NIH‐803IR Phase II Grant.
Synthesis of fatty acid phytyl esters in chloroplasts of Arabidopsis thaliana (617.7)
Authors: Wehler Regina , vom Dorp Katharina , Doermann Peter 
Published: June 2021

During senescence or stress, chloroplast membranes undergo severe changes. Galactolipids are broken down, releasing free fatty acids. At the same time, the plastoglobule size increases. Plastoglobules serve as lipid‐storage particles in chloropalsts, containing mostly neutral lipids such as triacylglycerol, tocopherol and fatty acid phytyl esters. Two genes (Phytyl Ester Sythase 1, PES1; Phytyl Ester Synthase 2, PES2) were identified that are primarily responsible for the synthesis of fatty acid phytyl esters in chloroplasts. In addition to phytyl ester synthesis, PES1 and PES2 harbor diacylglycerol acyltransferase activity and are presumably involved in the synthesis of triacylglycerol. An Arabidopsis double mutant (pes1 pes2) deficient in the two PES genes shows a reduction in the amounts of fatty acid phytyl esters and of triacylglycerol by more than 90 and by 30%, respectively. It is known that the bulk of triacylglycerol is produced by cytosolic acyltransferases at the ER. To investigate the role of PES1/PES2 in plastidial triacylglycerol production, we isolated chloroplasts from wild type and pes1 pes2 plants and analyzed the lipid composition of the individual chloroplast fractions. In addition to PES1 and PES2, the Arabidopsis genome contains 4 other genes encoding Esterase‐Lipase‐Thioesterase (ELT) proteins: ELT3, 4, 5 and 6, all of which are predicted to be chloroplast‐localized. We obtained insertion lines for ELT3, 4, 5 and 6 and analyzed the homozygous plants for triacylglycerol and fatty acid phytyl ester content.Grant Funding Source: Deutsche Forschungsgemeinschaft
Naringenin, a major bioactive lead of Thymus vulgaris, inhibits growth, induces apoptosis and modulates cell cycle and apoptosis‐regulatory gene expression in human cancer cells (657.18)
Authors: Abaza Mohamed Salah , Orabi Khaled , Al‐Attiyah Raja'a , Al‐Qattan Ebtehal 
Published: June 2021

In the present study Thymus vulgaris was extracted in 96% ethanol then subjected to solvent/solvent partitioning processes and purification techniques. The identities of the isolated compounds, naringenin (Nar) and aromadendrin (Aro) were identified using different spectral techniques. Nar inhibited the growth of human colorectal, breast, and melanoma cancer cell lines in a dose‐ and time‐dependent manner, arrested their growth in S‐phase and G2/M‐phase or S‐phase and potently induced their apoptosis. Nar differentially down‐regulated the expression of Cdk4, Cdk6, Cdk7, Bcl2, x‐IAP and c‐IAP‐2, differentially up‐regulated the expression of p18, p19, p21, caspases 3, 7, 8 and 9, Bak, AIF and Bax in both human colorectal and breast cancer cell lines. Nar could be a potential agent for prevention and/or treatment of human cancers.Grant Funding Source: this work was supported by Kuwait University, Research Grant No.[YS06/10]
Glutathione levels and susceptibility to chemically induced injury in human prostate cancer cell lines (663.11)
Authors: Lash Lawrence , Putt David , Jankovich Adam 
Published: June 2021

More aggressive or invasive prostate cancer cells (PCCs) are often resistant to chemotherapy and have poor prognosis. Two immortalized human PCC lines, PC‐3 (more aggressive) and LNCaP (less aggressive) cells, were compared with regard to cellular redox state and susceptibility to either oxidants or glutathione (GSH) depletors. We tested the hypothesis that compared to less aggressive PCCs, more aggressive PCCs exhibit higher GSH concentrations and are relatively resistant to cytotoxicity from oxidants. PC‐3 cells exhibited 4.2‐fold higher GSH concentration than LNCaP cells but only exhibited lower lactate dehydrogenase (LDH) release after toxicant exposures at some time points. Only LNCaP cells underwent diamide‐induced apoptosis. Expression of several proteins involved in stress response and regulation of cell growth and proliferation were measured to determine their possible role in redox state and susceptibility to toxicants. PC‐3 cells exhibited higher levels of pro‐apoptotic and lower levels of anti‐apoptotic proteins than LNCaP cells. Consistent with a compensatory response to oxidative stress, LNCaP cells exhibited higher levels of certain antioxidant and stress response proteins than PC‐3 cells. Thus, significant differences in redox status and expression of proteins involved in apoptosis and stress response may contribute to PCC aggressiveness.Grant Funding Source: None.
Leptin acutely inhibits respiratory function in neonatal rats (712.18)
Authors: Wollman Lila , Powell Gregory , Levine Richard , Fregosi Ralph 
Published: June 2021

Leptin resistance is associated with impaired respiratory function, obesity related respiratory disorders, and a higher incidence of respiratory illness in children of obese mothers. There have been few attempts to identify its site of action in respiratory centers of the brain and no studies on its respiratory effects in neonates. We hypothesize that the direct effect of leptin on the respiratory system is inhibitory, as it is in other brain regions, but that effects on metabolism may override this inhibition in the whole animal. We performed experiments on neonatal rat pups, postnatal day 0 to 6. Bath application of 300nM leptin to four brainstem spinal cord (BSSC) preparations had varied effects on burst amplitude and frequency of Cervical 4 ventral roots (C4VR). In three split bath BSSC preparations, 100uL of 0.5mg/ml leptin applied to the medullary compartment slowed or abolished C4VR rhythm, which recovered with washout. Whole bath application of 300nM leptin to five rhythmic medullary slices abolished hypoglossal rootlet rhythm, which recovered with washout. Microinjections of 0.5 mg/ml leptin, but not vehicle injection, into the pre‐Botzinger complex of two BSSC preps slowed or abolished C4VR rhythm. These preliminary results suggest that leptin receptors are located on pre‐Botzinger complex cells, and that leptin’s action is inhibitory.Grant Funding Source: Supported by ROIHD071302
Vitamin A and iron status of women and children in urban Cameroon before and after introduction of vitamin A‐fortified vegetable oil and iron‐fortified wheat flour (804.18)
Authors: Engle‐Stone Reina , Ndjebayi Alex , Nankap Martin , Gimou Marie‐Madeleine , Friedman Avital , Brown Kenneth 
Published: June 2021

Few data are available on the effectiveness of mass food fortification programs. We conducted representative surveys 2 y before and 1 y after introduction of vitamin A (VA)‐fortified cooking oil and iron‐fortified wheat flour to assess program impact on VA and iron status in urban Cameroon. In each survey, 10 different households were selected within each of the same 30 clusters (n=~300/survey). Malaria and plasma indicators of inflammation (CRP, AGP) and VA (retinol‐binding protein, pRBP) and iron (ferritin, pF; soluble transferrin receptor, sTfR) status were assessed among women 15‐49 y and children 12‐59 mo. Staple food intake was measured by FFQ, and post‐fortification oil and flour samples were collected. Pre‐fortification, low inflammation‐adjusted pRBP was common among children (33% < 0.83 µmol/L), but not women (2% < 0.78 µmol/L); > 20% of women and children had low adjusted pF. Oil and flour were each consumed by >80% of participants in the past week. Post‐fortification, 44% of oil and 76% of flour samples were fortified. Controlling for inflammation and malaria, there was no change in pRBP among women (1.41 to 1.40 µmol/L) or children (0.87 to 0.88 µmol/L), but pF increased (women: 37 to 47 µg/L; children: 39 to 51 µg/L, both P < 0.05) and sTfR decreased (7.7 to 6.2 and 10.6 to 8.2 mg/L, P < 0.01). Plausibility analyses will determine whether the observed changes are attributable to the fortification program.Grant Funding Source: Supported by the Michael and Susan Dell Foundation, Sight and Life, and UNICEF
Bioavailability of enteric‐coated microencapsulated calcium during pregnancy: a randomized crossover trial in Bangladesh (804.4)
Authors: Pezzack Brendon , Zlotkin Stanley , Abrams Steven , Hawthorne Keli , Al Mahmud Abdullah , Baxter Jo‐Anna , Aimone Phillips Ashley , Islam Munirul , Dimitris Michelle , Ahmed Tahmeed , Roth Daniel 
Published: June 2021

Prenatal calcium (Ca) and iron (Fe) supplements are recommended in settings of low dietary Ca intake and high prevalence of anemia. However, concurrent Ca and Fe administration may inhibit Fe absorption. Therefore, we developed a multi‐micronutrient powder containing Fe (60 mg), folic acid (400 µg), and Ca (0.5, 1.0 or 1.5 g) in which calcium carbonate granules were microencapsulated with a pH‐sensitive enteric coating to delay intestinal release and limit Ca‐Fe interactions. To compare the fractional intestinal absorption (fAb) of Ca from enteric‐coated (EC) Ca granules versus uncoated (non‐EC) granules, we conducted a randomized crossover trial among pregnant women (n=49) in Dhaka. fAb was estimated by a dual stable isotope method (44Ca‐labeled granules and intravenous 42Ca), based on the relative recovery of 44Ca vs 42Ca in urine over 48 hours. Mean (±SD) fAb from EC Ca was significantly less than from non‐EC Ca (2.7±2.2 % vs. 16.5±10.0 %; p<0.0001) at all 3 Ca doses. In conclusion, the pH‐sensitive enteric coating substantially reduced Ca absorption. Therefore, in its current formulation this novel enteric‐coated Ca‐Fe supplement is not suitable for clinical use.Grant Funding Source: Supported by Saving Lives at Birth