bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the Details of the Catalytic Mechanism of Alkanesulfonate Monooxygenase
Authors: Robbins John M , Ellis Holly R 
Published: June 2021

Elemental sulfur is essential for the synthesis and functionality of certain biological cofactors and proteins. When excess sulfate is not readily available, Escherichia coli expresses a series of proteins implicated in the uptake of sulfur from alternative environmental sources. Notably among these sulfate‐starvation induced proteins is the two‐component alkanesulfonate monooxygenase system composed of an NAD(P)H‐dependent FMN reductase (SsuE) and a FMNH2‐dependent monooxygenase (SsuD). The details of the catalytic mechanism governing the desulfonation reaction of SsuD are under active investigation.Previous structural and kinetic studies have implicated an active site base serving a role in catalysis. Several possibilities for this active‐site base were identified, and mutagenesis was performed in order to assess the importance of each residue in catalysis. Kinetic Studies were performed to determine how these substitutions altered the kinetic parameters compared to wild type SsuD, and deuterium‐isotope studies were performed to evaluate further the mechanism of desulfonation. These results provided valuable insight into the overall catalytic mechanism of SsuD.
Sphingosine kinase inhibition to sensitize hormone‐resistant prostate cancer cells to docetaxel
Authors: Pshezhetskiy Dmitry 
Published: June 2021

It has recently been shown that docetaxel chemotherapy is effective in prolonging life in patients with prostate cancer. We have investigated potential ways of increasing the effectiveness of chemotherapy in this disease. We have previously reported that sphingosine kinase‐1 (SK1) inhibition is a key step in docetaxel‐induced apoptosis in the PC‐3 prostate cancer cell line (Pchejetski et al, Cancer Res 2005) and that pharmacological SK1 inhibition is chemosensitizing in the docetaxel‐resistant prostate cancer LNCaP cell line (Pchejetski et al, Mol Cancer Ther, 2008). In this current study we have addressed the mechanism of docetaxel‐induced apoptosis of PC‐3 cells and identified SK1‐dependent and ‐independent components. We have shown that SK1 inhibition by docetaxel is a two‐step process involving an initial loss of enzyme activity followed by a decrease in SK1 gene expression. We have demonstrated that both pharmacological and siRNA‐mediated SK1 inhibition leads to a four‐fold decrease in the docetaxel dose required to cause prostate cancer cell apoptosis.Overall we have identified a mechanism of docetaxel‐induced SK1‐mediated prostate cancer cell apoptosis. This work points to potential ways of increasing the effectiveness of chemotherapy for prostate cancer by SK1 inhibition.
Fetal lipid metabolism is regulated by the Liver X Receptor (LXR) in mice
Authors: Plosch Torsten , van Straten Esther M.E. , Huijkman Nicolette C.A. , Baller Julius F.W. , Kuipers Folkert 
Published: June 2021

The Liver X Receptors LXRa/ß are vitally important in regulating cholesterol and fatty acid metabolism in the adult. Aim of this study was to elucidate the role of LXR in the fetal mouse liver. Pregnant C57BL/6 mice or Lxra+/− mice crossed heterozygously were fed a diet containing the synthetic LXR agonist T0901317 from E10.5 until delivery. In fetuses and dams, gene expression and lipid levels were monitored. In the mouse fetus, hepatic expression of LXR target genes (e.g., Srebp1c, Fas and Abcg5) is low during gestation and increases after birth. Lxra itself is expressed at ~40 % of adult levels, whereas the expression of Lxrb is 2.5‐3 times higher than in adult control liver. Upon administration of T0901317, LXR target genes are activated in the fetal liver: expression of the cholesterol transporter Abcg5 is 45 times induced. Expression of Srebp1c and Fas is increased 2.0‐ to 5.3‐fold and 1.7‐ to 2.0‐fold, respectively. Consequently, triglyceride concentrations in fetal liver and plasma are raised up to 2.7‐ and 1.5‐fold. Cholesterol levels in plasma are doubled upon treatment, whereas hepatic cholesterol concentrations are unchanged. In Lxra−/− fetuses, these changes are reduced but not absent.ConclusionLxra and Lxrß are functionally active in fetal mouse liver when stimulated with the synthetic agonist T0901317. Similar to adult mice, cholesterol homeostasis and de novo lipogenesis can be influenced experimentally by administration of this agonist.Supported by the Dutch Heart Foundation (2004T048).
EXPLORING DOUBLE‐STRANDED RNA AS A POSSIBLE CHEMOTHERAPEUTIC AGENT
Authors: Schramm Danielle N. , Lepine Sandrine , Bell Jessica K. 
Published: June 2021

Pattern recognition receptors (PRRs) function in the innate immune system to alert the host to pathogenic components. Double‐stranded RNA (dsRNA), viral genomic material or a viral replication intermediate, trigger the PRRs toll‐like receptor 3 (TLR3), retinoic acid‐inducible gene I (RIG‐I), melanoma differentiation‐associated gene 5 (MDA5), and dsRNA‐dependent protein kinase receptor (PKR). Previous studies have reported that dsRNA stimulation induced TLR3‐dependent apoptosis.ObjectivesExamine 786‐O, OVCAR‐3, OVCA‐420, SKOV‐3, DOV‐13, CAOV‐3 cells for dsRNA receptor expression and determine dsRNA‐induced response.MethodsPRR expression was confirmed by RT‐PCR. Expression levels were determined via qPCR. Apoptotic response to dsRNA stimulation was measured by Hoechst staining 48h post‐stimulation.Results786‐O, SKOV‐3 and DOV‐13 show no response to dsRNA. RT‐PCR analysis showed that cell lines contained mRNA for all dsRNA receptors. qPCR showed a significant increase in PRR expression in those cell lines that underwent dsRNA‐induced apoptosis.ConclusionsFour dsRNA receptors are present in our cell lines. dsRNA receptor expression does not correlate with dsRNA induced apoptosis, but increased dsRNA receptor expression suggests receptor levels or altered signaling pathways may reduce sensitivity to dsRNA. Funding provided by National Cancer Institute & Jimmy V Foundation.
Rapamycin enhances G protein signaling in the budding yeast Saccharomyces Cerevisiae
Authors: Zhu Ming , Wang Yuqi 
Published: June 2021

Heterotrimeric G proteins are common signal transducers that are important for many cellular processes. Mechanisms that ensure accurate magnitude and specificity of G protein signaling are under intensive investigation. Here we demonstrate that in Saccharomyces cerevisiae, the activity of heterotrimeric G protein (Gpa1/Ste4/Ste18) that is required for mediating mating responses is augumented by the treatment of rapamycin, a drug that specifically inhibits TOR, i.e., the target of rapamycin. Both basal and mating pheromone‐induced activation of a mitogen‐activate protein kinase Kss1 are enhanced by rapamycin treatment. Genetic analysis indicates that the rapamycin effects are dependent on the existence of Ste4, Ste5, Ste11, Ste7 but not Ste2. Furthermore, the effect is abolished by overexpression of Gpa1, the alpha subunit of the G protein. Together, these data indicate that rapamycin directly or indirectly impact the interaction between Gpa1 and Ste4, and suggest that TOR might play an important role in regulating the magnitude of G protein signaling. Studies that are designed to investigate how Gpa1 and Ste4 interaction is impacted by rapamycin and TOR are underway.This work is supported by American Heart Association grants 302970.
Mismatches between the conceptual level of tests and faculty beliefs
Authors: Costa Manuel Joao , Gonçalves Leonor , Ludovico Paula , Oliveira Mário , Rodrigues Fernando , Sousa João Carlos 
Published: June 2021

Student learning of biochemical concepts can be promoted by the conceptual quality of items in written assessments. We present a "faculty centered" development prototype aimed at the improvement of written assessments.Summary of workA pool was created with all the written items presented in 2007‐2008 to freshmen and sophomores of a 6 year medical degree ‐ included were disciplines such as Biochemistry, Molecular Biology, Cell Biology, etc. Items were ranked by faculty (n=6) of different disciplines (including biochemistry faculty), according to a simple scale (1 to 5), based on: i. the presence of a context; ii. the type of cognitive process required to solve the item; iii. presence/absence of irrelevant difficulties.Summary of resultsThere was considerable inter‐rater variability on the classifications which were, in general, below initial expectations. Faculty regarded very highly the learning potential of the experience and converged on changes to improve item quality for 2008‐2009.ConclusionsThe conceptual level of items in written knowledge tests may be lower than faculty believe.Take‐home messagesThe prototype can be generalized to other institutions. Analysis of future new items and further empirical evidence are needed to corroborate the prototype's power for the improvement of the conceptual level of Biochemistry and Molecular Biology tests.
Snack selection influences satiety responses in adult women
Authors: Furchner‐Evanson Allison , Petrisko Yumi , Howarth Leslie S. , Nemoseck Tricia , Kern Mark 
Published: June 2021

Some research suggests that snacking can promote a healthy body weight while other studies suggest the opposite; therefore, identification of satiating snack foods may prove to be valuable for weight control. The effect of different snack foods on satiety and plasma glucose and hormone responses was assessed. Nineteen fasted adult women consumed two 238 kcal snacks (dried plums or low‐fat cookies), 238 kcal white bread, or water on separate days. Subjects completed satiety index (SI) scales prior to snack consumption and again every 15 minutes for 2 hours following initiation of intake. Blood samples were collected at baseline and 15, 30, 45, 60, 90, and 120 minutes following intake. At the end of the 120‐minute test period, subjects were presented with a meal to be consumed until satisfied. Satiety index was higher (p=0.05) for dried plums versus low‐fat cookies. There was no difference in post‐snack consumption between the dried plums and low‐fat cookie trials. Dried plums elicited lower (p=0.05) plasma glucose and insulin area under the curve than low‐fat cookies and tended (p=0.056) to promote a greater plasma ghrelin area over the curve. These results suggest that consuming dried plums as a snack suppresses appetite relative to a commercially available low‐fat cookie perhaps by producing lower glucose and/or appetite‐regulating hormone concentrations.Supported by the CA Dried Plum Board.
Measurement of de novo lipogenesis in humans during lactation
Authors: Mohammad Mahmoud A , Sunehag Agneta L , Haymond Morey W 
Published: June 2021

BackgroundMilk fat is composed of 98% triglycerides (TG) and provides infants with ~50 % of their calories. Mammary gland de novo lipogenesis contributes significantly to milk fat in animals. However, there are no data regarding this process in humans.HypothesesIncorporation of 13C carbons from [U‐13C]glucose into fatty acids (FAs) and glycerol in TG will be, higher in milk TG than in plasma, and higher during H‐CHO than H‐F diet.Subjects7 healthy lactating women were studied in a crossover, randomized design during isocaloric, isonitrogenous, H‐F (30%CHO, 55%fat) and H‐CHO (60%CHO, 25%fat) diets. Following feeding for 7 days on each diet, women were continuously infused with [U‐13C]glucose for 5h following a 12h fast and during 7h of feeding. Incorporation of 13C from [U‐13C]glucose into FAs and glycerol was measured in both plasma and milk using GC‐MS.ResultsIncorporation of 13C from [U‐13C]glucose into milk FAs increased (p<0.05) with the increased chain length of the FAs from C2 to C12 then, declined in C14 and was not detected in FAs longer than C16. During meal absorption, enrichment of 13C was ~3 fold higher in milk FA and ~7 fold higher in milk glycerol compared to plasma FAs and glycerol. During fasting, 25% and 6% of medium chain FAs (MCFAs) (C6‐C12) were derived from glucose following H‐CHO and H‐F diets, respectively. However, during feeding, de novo lipogenesis from glucose was 60% and 20% of MCFAs during both H‐CHO and H‐F diet, respectively.ConclusionsThe human mammary gland is capable of de novo lipogenesis, mainly MCFAs, which is increased during a H‐CHO diet. RO1DK 55478, HD 37857, MO1‐RR‐00188‐34.
Contribution of complementary feeding (CF) to nutrient intake of low‐income rural infants, aged 6 to 12 mo, in Guatemala City: Principal sources of macro‐ and micronutrients
Authors: Hernandez Liza Mariana , Campos Raquel , Enneman Anke , Solomons Noel W. 
Published: June 2021

ObjectiveTo rank the food and beverage elements of the infants' diets in terms of the principal contributors to each macro‐ and micronutrient of interest.Methods3 non‐consecutive 24‐h recalls were collected from mothers of 64 infants, aged 6‐12 mo, in the rural village Santo Domingo Xenacoj. We modeled Maternal Milk (MM) intake based on total energy recommendations. The macro‐ and micronutrient contribution from each of the food and beverage items reported were ranked in relation to the total reported intakes among the infants.ResultsThe top five sources of protein were: Incaparina; MM; white rolls; pasta; and tortilla, accounting for 52.5% of the total. MM was the leading sources of fat, vit C, ribo, and nia, and figured among the top 10 sources of all macro‐ and micronutrients with the exception of CHO, Fe and Zn. Table sugar is fortified with Vit A in Guatemala and that item was the first source of the vitamin, accounting for 24.1% of its total consumption; MM was second, providing 21.6%. Overall, 21%of CF items were fortified. 5% of CF could be classified as special "baby foods," with the remainder being family food.ConclusionsThe contribution of MM is indispensable in contributing toward an adequate macro‐ and micronutrient intake of infants in the second semester of life.Funded in part by Sight & Life and Wyeth Nutrition
Optimized use of nutrient dense foods in a thrifty diet
Authors: Luick Bret Roger , Bersamin Andrea 
Published: June 2021

BackgroundIt is unclear whether national dietary guidelines which are promoted by federal nutrition education programs such as EFNEP are economically feasible for low income families‐particularly in a climate of increasing costs of food and other household costs.ObjectivesThe objective of this work was to develop a food plan for low‐income Alaskans which reflect current local prices and dietary habits while remaining within the constraints of federal dietary recommendations and SNAP benefits.MethodsFollowing the paradigm set forth by the USDA Center for Nutrition Policy Promotion, nonlinear optimization was used to construct a balanced diet starting from current baseline dietary practices, represented by recent 24 hour recalls of the Alaska Expanded Food and Nutrition Education Program database. Model constraints included MyPryamid servings, macro‐ and micronutrient recommendations and food stamp benefits.OutcomesBaseline diet was low in fruit and vegetable servings and high in added sugars and fat, but was affordable. A feasible optimized solution for a revised food plan required introduction of nutrient dense foods.
Protein, carbohydrate and vitamin K related to physical performance in older women
Authors: Mojtahedi Mina C , Chapman‐Novakofski Karen M , Rosengren Karl S , McAuley Edward , Evans Ellen M 
Published: June 2021

Dietary factors may contribute to functional limitations potentially through body composition in older adults. To explore this, dietary intake via 24h recall and physical performance changes in timed up‐and‐go (UPGO) and 7m walk w/ obstacle (7OB) were assessed over 2 years in women (Black=50, White=137; M±SD age: 68±6 yrs, BMI: 27.7±5.1 kg/m2). Lean (LM) and fat mass (FM) were assessed with DXA. Significant reduction in LM 0.4±1.7 kg (0.8%) occurred. After 2 years, 109 and 106 women (FAST) improved UPGO (9.5±8.1%) and 7OB (12.3±9.3%); 78 and 81 women (SLOW) reduced UPGO (8.6±6.9%) and 7OB (8.8±6.5%) performance. Energy intake was 1666±488 kcal; protein 76±25 g (19±5 % of energy); carbohydrate 205±66 g (50±9 %); fat 63±27 g (33±8 %); vitamin D 3.1±2.5 μg; vitamin A 1378±1334 RE; vitamin K 128±153 μg; calcium 824±410 mg. No absolute nutrient intakes differed between groups. Controlling for race, relative protein (19±5, 17±4 %, FAST and SLOW respectively; p=0.02) and relative vitamin K (92±117, 61±58 μg/1000kcal; p=0.03) differed in UPGO; relative carbohydrate (50±9, 48±9 %; p=0.03) differed in 7OB. Vitamin D intake did not differ between groups in UPGO (p=0.79) or 7OB (p=0.37). Results were not changed when controlling for race and BMI, LM or FM change. Protein, carbohydrate, and vitamin K intake may be related to changes in physical performance in older women, independent of energy intake or changes in body composition.Grant Funding SourceNIH RO1‐AG020118
The Prevalence of Use of Personal Digital Assistants (PDA) by Clinical Dietitians in Delaware Valley
Authors: Fang Chengshun , Fireovid Kate 
Published: June 2021

ObjectiveThe first purpose of this study was to examine the prevalence of PDA use among clinical dietitians and identify the most commonly reported applications. Secondly, we aimed to establish the most commonly cited reasons for choosing not to use PDAs at work. Finally, we analyzed the influence of dietitian age and years of experience on their tendency to use a PDA at work.MethodsEmail invitations were sent to randomly selected 77 Clinical dietitians in the Delaware Valley. 40 of them responded by completed an online survey.ResultsForty percent of respondents reported use of a PDA compared with 60% of respondents who did not. Among the clinical dietitians using PDAs, 62.5% used nutrition assessment tools, such as diet assessment, 25% used nutrition reference tools, and 12.5% used medical dictionaries. Of the 60% of the dietitians who do not use PDAs for work, 33% reported they felt the PDA was not valuable for their work, 25% stated PDAs were too expensive, and 21% reported lack of knowledge in PDA operation. The proportion of PDA users to non users for this study was independent of age (p = 0.17) and years of experience (p = 0.90).ConclusionPDAs are valuable tools. However, the results of this study suggest that use of PDAs is not common among clinical dietitians. Age and years of clinical experience do not appear to influence the tendency to use PDAs, suggesting that employer attempts to integrate PDAs to the work place would be well received across the workforce.
Effect of oolong tea, oolong tea polyphenols and oolong tea catechins on glucoregulatory control in overweight and obese men
Authors: Stote Kim S , Courville Amber , Harris G. Keith , Paul David R , Rumpler William V , Clevidence Beverly A , Baer David J 
Published: June 2021

Oolong tea, as well as the polyphenols it contains, has been shown to alter physiological processes related to glucose regulation. As part of a double blinded randomized crossover design study, 19 overweight and obese men (BMI 25‐34, ages 25‐64 years) consumed a controlled diet at weight maintenance along with 5 treatment beverages: 1) oolong tea, 2) oolong tea with added catechins, 3) oolong tea with added oolong tea polyphenols, 4) water with caffeine (matched for caffeine content of oolong tea) and 5) water. Each subject consumed four 350 ml servings (1400 ml/day) of the treatment beverages per day with breakfast, lunch, mid‐afternoon and dinner for four days. On the fifth day, after a 12 hour fast, subjects consumed a mixed meal tolerance test breakfast (450 kcals, 85 g carbohydrate, 10 g fat, 8 g protein) along with the treatment beverage. Biomarkers, glucose, insulin, triglycerides and the homeostasis model assessment of insulin resistance (HOMA‐IR), were measured every 30 minutes during a four hour period. Results showed no significant postprandial changes in glucose, insulin, triglycerides and HOMA‐IR after consumption of the treatment beverages. Consumption of the oolong tea treatments had no adverse effects on glucoregulatory biomarkers in overweight and obese men.Supported by US Department of Agriculture and Suntory Corporation, Osaka, Japan
Bioaccessibility and angiotensin I converting enzyme (ACE) inhibitory activity of asiatic and medecassic acids from Centella asiatica.
Authors: Muangnoi Changnarong , Chareonkiatkul S. , Kriengsinyos W. , Chitchumroonchokchai C. 
Published: June 2021

Centella asiatica (C.asiatica), locally known as Bua‐bok, is a local Thai herb consumed in both fresh squeezed juice and fresh form. Although triterpenoids from C. asiatica are claimed to provide health benefits, the bioavailability of triterpenoids in this plant is unknown. The first aims of the present study was to determine bioaccessibilty of asiatic acid and medecassic acid using the coupled in vitro digestion and Caco‐2 model. ACE inhibitory activity, the primary property of widely used hypertensive drugs, also was investigated. Both triterpenoids were stable during simulated digestion and 60‐70% partitioned in the aqueous fraction of digesta. Differentiated cultures of Caco‐2 cells accumulated 30‐40% of asiatic acid and medecassic acid from diluted aqueous fraction generated during digestion of C. asiatica in a time dependent manner and the compounds were stable once accumulated. Ethanolic extract of freeze dried C. asiatica and C. asiatica juice (0.2% pennywort) also inhibited ACE cleavage of HHL to hippuric acid with IC50 of 1 mg and 1.6 mg, respectively, suggesting potential use as natural anti‐hypertensive products.Supported by Faculty of Graduate Studies, Mahidol University.
Effect of Pistachios on Postprandial Glucose and Insulin Levels and Gut Satiety Hormone Responses.
Authors: Kendall Cyril , Esfahani Amin , Josse Andrea , Jenkins David 
Published: June 2021

BackgroundNut consumption is associated with reduced risk of CHD and type 2 diabetes and healthy body weights. Previous studies demonstrated that pistachios decrease the postprandial glycemic response of carbohydrate foods.ObjectiveTo assess the effect of pistachios on postprandial serum insulin/glucose levels and gut satiety hormone responses.MethodsFasted subjects (9M, 6F) consumed 3 different meals in random order. Test meals, with similar macronutrient profiles, consisted of white bread (WB) plus 2oz of pistachios, and; WB plus butter and cheese. The control meal was WB. Capillary finger‐prick and venous blood samples were taken and subjective satiety measures via a visual analogue scale were assessed over 3 hours.ResultsCompared to the control, peak postprandial glucose concentration was reduced in both test meals while plasma insulin was not different. However, GIP iAUC for WB was significantly lower than for the test meals. GLP‐1 levels were consistently higher after WB+Pistachio meal compared to other meals and GLP‐1 iAUC of both WB+Pistachio and WB+Cheese meals were significantly higher than WB control meal. Despite absence of changes in VAS satiety scores, several hunger markers were increased over the first hour in the control meal.ConclusionReducing postprandial glycemia and altering gut hormones may be further mechanisms by which pistachios contribute to health.