bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nutritional influences on maternal autonomic function during pregnancy
Authors: Caulfield Laura E. , Zavaleta Nelly , Chen Ping , Merialdi Mario , DiPietro Janet A. 
Published: April 2009

The objective of this study was to identify influences on longitudinal changes in autonomic function during pregnancy. We studied 195 low-income Peruvian women who were subjects in a randomized controlled trial of zinc supplementation and fetal neurobehavioral development. Maternal cardiorespiratory status and electrodermal activity were assessed at 20, 24, 28, 32, 36, and 38 weeks’ gestation over a 50-min session. At baseline (10–16 weeks), and at 28 and 36 weeks’ gestation, mass and height, arm and calf circumferences, and skinfold thicknesses were assessed, and blood was taken to measure hemoglobin, hematocrit, and plasma zinc concentration. Measures of heart period (HP), respiratory period (RP), respiratory sinus arrhythmia (RSA), skin conductance level (SCL), and mean arterial pressure (MAP) were analyzed using longitudinal models. Having a hemoglobin concentration <10.5 g·dL–1 at 28 weeks was associated with shorter HP and RP and lower RSA, and change in hemoglobin from baseline to 36 weeks was associated with decreased SCL. Further, 3 measures were associated with variation in fat or fat-free mass in the calf; RSA was negatively associated with changes in calf muscle area over pregnancy, while changes in calf fat area were positively associated with MAP and SCL. Variability in autonomic function during the second half of pregnancy is associated with hematologic status and changes in lower limb body composition across pregnancy.
Non-high-density-lipoprotein cholesterol and cardiovascular risk factors among adolescents with and without impaired fasting glucose
Authors: Liu Jian , Joshi Divya , Sempos Christopher T. 
Published: April 2009

To evaluate how non-high-density-lipoprotein (non-HDL) is associated with impaired fasting glucose (IFG) and clustered metabolic risk (MR) factors among adolescents, we pooled 2764 adolescents, aged 12–19 years, from the National Health and Nutrition Examination Survey from 3 time periods (1999–2000, 2001–2002, and 2003–2004) who were free of diabetes and had fasted overnight for this analysis. IFG was defined as 100 ≤ glucose ≤ 125 mg·dL–1. Age- and sex-specific cut-offs were used for 4 MR factors: higher levels of triglycerides, waist circumference, blood pressure, and lower levels of HDL. Clustered MR was defined as having any 2 of the 4 factors. Overall, approximately 11% of adolescents had IFG. The mean level of non-HDL cholesterol was much higher in those with IFG than in those without IFG, with adjustment for certain confounding variables (121.4 vs. 110.1 mg·dL–1; p < 0.05). This difference could still be observed in adolescents with one or more clustered MR factors. However, there were no statistical differences in low-density-lipoprotein (LDL) level. Compared with those who were without IFG and not at high levels of non-HDL — after adjustment for age, sex, race, current smoking, and body mass index — the odds of having clustered MR factors were 1.08 (95% CI, 0.65–1.82) for those with IFG and low non-HDL cholesterol, 3.55 (2.29–5.48) for those without IFG but with high non-HDL cholesterol, and 10.10 (3.67–27.80) for those with both IFG and high non-HDL cholesterol. Moreover, those with IFG and at increased risk of obesity were more likely to have higher levels of non-HDL cholesterol (odds ratio (95% CI): 4.41 (2.28–8.50)), compared with those without IFG and not at increased risk of obesity. In summary, prediabetic adolescents with IFG and high levels of non-HDL cholesterol are more likely to have clustered MR factors. Thus, the levels of non-HDL cholesterol may be an important indicator in monitoring cardiovascular disease risk among adolescents with IFG.
Age and physical activity status effects on appetite and mood state in older humans
Authors: Apolzan John W. , Flynn Michael G. , McFarlin Brian K. , Campbell Wayne W. 
Published: April 2009

This study examined the influences of age and chronic physical activity status on appetite and mood state. Groups of younger inactive, younger active, older inactive, and older active men and women completed questionnaires each waking hour, rating appetite and mood state for 1 day. Maximal oxygen consumption was 20% lower in older than in younger (p < 0.001) subjects, and 32% lower in inactive than in active (p < 0.001) subjects. Mean hunger (older, 4 ± 1; younger, 5 ± 1 arbitrary units (AU); p < 0.01) and desire to eat (older, 3 ± 1; younger, 4 ± 1 AU; p < 0.01) were lower in older than in younger subjects. Nadir arousal was higher for the active subjects (active, 3 ± 1; inactive, 2 ± 1 AU; p < 0.05). Nadir arousal, nadir pleasantness, and mean pleasantness were higher for the older subjects (p < 0.05). Physical activity status does not influence appetite or the age-associated declines in hunger or desire to eat. The increased nadir arousal of the physically active and older groups is consistent with these subjects experiencing less extreme sleepiness.
Physiological responses and energy cost during a simulation of a Muay Thai boxing match
Authors: Crisafulli Antonio , Vitelli Stefano , Cappai Ivo , Milia Raffaele , Tocco Filippo , Melis Franco , Concu Alberto 
Published: April 2009

Muay Thai is a martial art that requires complex skills and tactical excellence for success. However, the energy demand during a Muay Thai competition has never been studied. This study was devised to obtain an understanding of the physiological capacities underlying Muay Thai performance. To that end, the aerobic energy expenditure and the recruitment of anaerobic metabolism were assessed in 10 male athletes during a simulation match of Muay Thai. Subjects were studied while wearing a portable gas analyzer, which was able to provide data on oxygen uptake, carbon dioxide production, and heart rate (HR). The excess of CO2 production (CO2 excess) was also measured to obtain an index of anaerobic glycolysis. During the match, group energy expenditure was, on average (mean ± standard error of the mean), 10.75 ± 1.58 kcal·min–1, corresponding to 9.39 ± 1.38 metabolic equivalents. Oxygen uptake and HRs were always above the level of the anaerobic threshold assessed in a preliminary incremental test. CO2 excess showed an abrupt increase in the first round, and reached a value of 636 ± 66.5 mL·min–1. This parameter then gradually decreased throughout the simulation match. These data suggest that Muay Thai is a physically demanding activity with great involvement of both the aerobic metabolism and anaerobic glycolysis. In particular, it appears that, after an initial burst of anaerobic glycolysis, there was a progressive increase in the aerobic energy supply. Thus, training protocols should include exercises that train both aerobic and anaerobic energetic pathways.
Physical activity levels of older community-dwelling adults are influenced by summer weather variables
Authors: Brandon Caitlin A. , Gill Dawn P. , Speechley Mark , Gilliland Jason , Jones Gareth R. 
Published: April 2009

Adequate daily physical activity (PA) is important for maintaining functional capacity and independence in older adults. However, most older adults in Canada do not engage in enough PA to sustain fitness and functional independence. Environmental influences, such as warmer daytime temperatures, may influence PA participation; however, few studies have examined the effect of summertime temperatures on PA levels in older adults. This investigation measured the influence of summertime weather variables on PA in 48 community-dwelling older adults who were randomly recruited from a local seniors’ community centre. Each participant wore an accelerometer for a single 7-consecutive-day period (between 30 May and 9 August 2006) during waking hours, and completed a PA logbook to remark on major daily PA events. Local weather variables were collected from a national weather service and compared with PA counts per minute. Regression analysis revealed a curvilinear relationship between log-transformed PA and mean daily temperature (r2 = 0.025; p < 0.05). Linear mixed effects models that accounted for repeated measures nested within individuals were performed for monthly periods, meteorological variables, sex, age, and estimated maximal oxygen consumption, with PA as the dependent variable. Age and Air Quality Index remained significant variables within the model. Higher fitness levels had no effect on allowing individuals to perform more vigorous PA in warmer temperatures.
Many adult Canadians are not meeting current calcium recommendations from food and supplement intake
Authors: Vatanparast Hassanali , Dolega-Cieszkowski Jadwiga H. , Whiting Susan J. 
Published: April 2009

The objective of this study was to determine trends in calcium intake from foods of Canadian adults from 1970–1972 to 2004. We compiled the calcium intake of adults (aged ≥19 years) from foods from Nutrition Canada (1970–1972; n = 7036); 9 provincial nutrition surveys (1990–1999; n = 16 915); and the 2004 Canadian Community Health Survey 2.2 (n = 20 197). Where possible, we used published confidence intervals to test for significant differences in calcium intake. In 2004, the mean calcium intake of Canadians was below Dietary Reference Intake recommendations for most adults, with the greatest difference in older adults (≥51 years), in part because the recommended calcium intake for this group is higher (1200 mg) than that for younger adults (1000 mg). The calcium intake of males in every age category was greater than that of females. Calcium intake increased from 1970 to 2004, yet, despite the introduction of calcium-fortified beverages to the market in the late 1990s, increases in calcium intake between 1970 and 2004 were modest. Calcium intakes in provinces were mostly similar in the 1990s and in 2004, except for women in Newfoundland and Labrador, who consumed less, especially in the 1990s, and for young men in 2004 in Prince Edward Island, who consumed more. When supplemental calcium intake was added, mean intakes remained below recommended levels, except for males 19–30 years, but the prevalence of adequacy increased in all age groups, notably for women over 50 years. The calcium intake of Canadian adults remains in need of improvement, despite fortification and supplement use.
Stimulation of muscle anabolism by resistance exercise and ingestion of leucine plus protein
Authors: Tipton Kevin D. , Elliott Tabatha A. , Ferrando Arny A. , Aarsland Asle A. , Wolfe Robert R. 
Published: April 2009

Leucine is known to stimulate muscle protein synthesis and anabolism. However, evidence for the efficacy of additional leucine to enhance the response of muscle anabolism to resistance exercise and protein ingestion is unclear. Thus, we investigated the response of net muscle protein balance to ingestion of additional leucine with protein in association with resistance exercise. Two groups of untrained subjects performed an intense bout of leg resistance exercise following ingestion of 1 of 2 drinks: flavored water (PL); or 16.6 g of whey protein + 3.4 g of leucine (W+L). Arteriovenous amino acid balance across the leg was measured to assess the anabolic response of muscle in each group. Arterial amino acid concentrations increased in response to ingestion of W+L. Amino acid concentrations peaked between 60 and 120 min after ingestion, and then declined to baseline values. Valine concentration decreased to levels significantly lower than baseline. Net balance of leucine, threonine, and phenylalanine did not change following PL ingestion, but increased and remained elevated above baseline for 90–120 min following W+L ingestion. Leucine (138 ± 37 and –23 ± 23 mg), phenylalanine (58 ± 28 and –38 ± 14 mg), and threonine (138 ± 37 and –23 ± 23 mg) uptake was greater for W+L than for PL over the 5.5 h following drink ingestion. Our results indicate that the whey protein plus leucine in healthy young volunteers results in an anabolic response in muscle that is not greater than the previously reported response to whey protein alone.
Pro-apoptotic effects of parathyroid hormone in intestinal cells
Authors: Calvo Natalia , German Olga , Russo de Boland Ana , Gentili Claudia 
Published: April 2009

Apoptosis, a form of programmed cell death, is a process fundamental to normal growth and development, immune response, tissue remodeling after injury or insult, and homeostasis of the intestinal epithelium. Recently, it has become apparent that apoptosis is a crucial process in skeletal development and homeostasis, and that signaling by the parathyroid hormone (PTH) receptor can either promote or suppress apoptosis depending on the cellular context. In this study, we evaluated the role of PTH in intestinal apoptosis using human colonic Caco-2 cells. To that end, Caco-2 cells were exposed to PTH (10−8 mol/L) for 1–5 days. Evaluation of cell survival by use of resazurin staining, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) staining, and crystal violet staining revealed that PTH treatment diminishes the number of viable cells. Assessment of cells after PTH treatment by use of propidium iodide showed that the hormone increased the number of red-stained (dead) cells (178%, 5 days). Moreover, we found that the hormone induced disruption of actin filaments with changes to cellular shape, alteration of cell-to-cell junctions, externalization of membrane phosphatidylserine, chromatin condensation, and DNA fragmentation of the nucleus, which are morphological features consistent with apoptosis. In addition, PTH treatment revealed a cytosolic staining pattern of 14-3-3. However, the significance of such differential localization for 14-3-3 function remains unknown. Taken together, the present study suggests that PTH promotes apoptosis in Caco-2 intestinal cells.
Characterization of a group 1 late embryogenesis abundant protein in encysted embryos of the brine shrimpArtemia franciscana
Authors: Sharon Michelle A. , Kozarova Anna , Clegg James S. , Vacratsis Panayiotis O. , Warner Alden H. 
Published: April 2009

Late embryogenesis abundant (LEA) proteins are hydrophilic molecules that are believed to function in desiccation and low-temperature tolerance in some plants and plant propagules, certain prokaryotes, and several animal species. The brine shrimp Artemia franciscana can produce encysted embryos (cysts) that enter diapause and are resistant to severe desiccation. This ability is based on biochemical adaptations, one of which appears to be the accumulation of the LEA protein that is the focus of this study. The studies described herein characterize a 21 kDa protein in encysted Artemia embryos as a group 1 LEA protein. The amino acid sequence of this protein and its gene have been determined and entered into the NCBI database (no. EF656614). The LEA protein consists of 182 amino acids and it is extremely hydrophilic, with glycine (23%), glutamine (17%), and glutamic acid (12.6%) being the most abundant amino acids. This protein also consists of 8 tandem repeats of a 20 amino acid sequence, which is characteristic of group 1 LEA proteins from non-animal species. The LEA protein and its gene are expressed only in encysted embryos and not in larvae or adults. Evidence is presented to show that the LEA protein functions in the prevention of drying-induced protein aggregation, which supports its functional role in desiccation tolerance. This report describes, for the first time, the purification and characterization of a group 1 LEA protein from an animal species.
Influence of vitamins and osmolites on growth and bacteriocin production byLactobacillus salivariusCRL 1328 in a chemically defined medium
Authors: Vera Pingitore Esteban , Hebert Elvira María , Sesma Fernando , Nader-Macías María Elena 
Published: April 2009

The aim of this study was to analyze the influence of vitamins, glycerol, and salts on the growth and bacteriocin production by Lactobacillus salivarius CRL 1328, a human vagina isolate, by using a chemically defined medium to determine the optimal conditions for salivaricin production. The single omission of d-biotin, thiamine, p-aminobenzoic acid, folic acid, or cyanocobalamin did not affect the bacterial growth, whereas the removal of nicotinic acid, riboflavin, and pyridoxal produced a decrease of about 30% in the growth rate. Maximum salivaricin activity was observed after the addition of 5 or 10 g/L of NaCl. On the basis of the nutritional requirements and the levels of salivaricin production, a new optimized and simplified defined medium (SDM–NaCl) for L. salivarius CRL 1328 bacteriocin production was formulated. The kinetics of salivaricin production in SDM–NaCl and in the complex media LAPTg revealed that bacteriocin production was growth linked. A combination of tricine – sodium dodecyl sulfate polyacrylamide gel electrophoresis (Tricine–SDS–PAGE), Lumitein protein gel staining, and a bioassay for antibacterial activity indicated that the molecular mass of salivaricin CRL 1328 is about 4.5 kDa. The partially purified bacteriocin, obtained from SDM–NaCl after concentration, allowed for the design of a relatively simple method for the recovery of a biologically active protein.
A novel nicotine catabolic plasmid pMH1 in Pseudomonas sp. strain HF-1
Authors: Wang Meizhen , Yang Guiqin , Min Hang , Lv Zhenmei 
Published: April 2009

Attempts were made to acquire a plasmid-loss mutant via various methods (spontaneous mutation, SDS, and mitomycin C), among which the method involving mitomycin C (10 µg/mL) has been proven successful. Concomitant with the loss of the plasmid in Pseudomonas sp. strain HF-1, the cured derivative was identified as having a nicotine-negative (Nic–) phenotype, named mutant strain 6-13 (Nic–). After plasmids were transferred from strain HF-1 (named plasmid pMH1) to the mutant strain 6-13, the mutant strain acquired nicotine-degrading ability, called 6-13 transformant (Nic+). There were no differences in growth or nicotine-degrading efficiency between strain HF-1 (wild-type strain) and strain 6-13 transformant. After pMH1 was transferred to Escherichia coli strain Top10 (Nic–), a distant relative of Pseudomonas, it also gained nicotine-degrading ability, showing the highest nicotine degradation efficiency at pH 7.0, the optimal pH for growth of E. coli. The hsp gene, which encodes 6-hydroxy-3-succinoylpyridine hydroxylase, is involved in nicotine degradation in Pseudomonas putida strain S16 and was present in pMH1 but not in pAO1, the well-known nicotine degradation plasmid in Arthrobacter nicotinovorans . It was demonstrated that plasmid pMH1 is a novel nicotine-degrading plasmid.
Therapeutic effects of Nigella sativa on chronic HAART-induced hyperinsulinemia in ratsThis article is one of a selection of papers from the NATO Advanced Research Workshop on Translational Knowledge for Heart Health (published in part 2 of a 2-part Special Issue).
Authors: Chandra Surabhi , Murthy Subramanyam N. , Mondal Debasis , Agrawal Krishna C. 
Published: April 2009

Prolonged use of highly active antiretroviral therapy (HAART) is associated with insulin resistance in HIV-1-positive patients. Small animal models that recapitulate the long-term effects of HAART may facilitate the identification of therapeutic agents to suppress these side effects. We investigated the protective effects of black seed oil (BSO) from Nigella sativa in Sprague–Dawley rats treated with a daily HAART regimen for 7 months. The antiretroviral drugs, consisting of nelfinavir (200 mg/kg), zidovudine (50 mg/kg), and efavirenz (20 mg/kg), were mixed with diet with or without BSO (400 µL/kg) supplementation. Significant increases in insulin and C-peptide levels were observed in HAART-treated groups, and concomitant BSO treatment reduced this hyperinsulinemia. Interestingly, HAART-treated rats showed reduced size of pancreatic islets that was not seen in BSO-exposed rats. In vitro studies showed that nelfinavir, alone and in combination with HAART, induced oxidative stress and decreased glucose-induced insulin production in INS-1 cells. Suppressed insulin production was restored in cells coexposed to either BSO or thymoquinone. Our findings demonstrated that chronic HAART may increase serum insulin levels by dysregulating both insulin production by β cells and insulin action at the periphery. These deleterious effects may be prevented by dietary supplementation with BSO.
Habitat selection of the Eurasian beaver (Castor fiber) near its carrying capacity: an example from Norway
Authors: Pinto B. , Santos M. J. , Rosell F. 
Published: April 2009

The Eurasian beaver ( Castor fiber L., 1758) was extirpated until the beginning of the twentieth century, but is becoming re-established over much of its former range. Since this rodent is considered both a keystone species and an ecosystem engineer, it is important to understand its habitat use in a population near its carrying capacity. In this study, we tested the hypothesis that habitat selection in beaver populations near their carrying capacities is different from populations that are still expanding. Also, a resource-selection model for the species using logistic regression was derived. Although most of the tested habitat variables were important for both populations expanding and populations near their carrying capacities, there were significant differences in the importance of the presence of shrub and (or) hardwood on the riverbank and the river flow speed. Beaver presence was associated with narrower river widths, bank slope, water depth close to the bank, silt–soil bank substrates, cover of deciduous forest, and cover of shrub and (or) hardwood on the bank. The models had high overall accuracy (overall correct classification >85%, area under the curve >90%). The final model is thought to be robust and applicable to areas with similar river and vegetation characteristics. Our results extend the habitat selection patterns of beavers to patterns at high-density populations.
Habitat selection by nesting and brood-rearing sharp-tailed grouse
Authors: Goddard Alicia D. , Dawson Russell D. , Gillingham Michael P. 
Published: April 2009

Breeding success is a critical component of population stability and is often influenced by the habitats used during the breeding season. Current hypotheses suggest that sharp-tailed grouse ( Tympanuchus phasianellus (L., 1758)) select nest and brood-rearing habitats that provide both lateral and overhead cover to avoid detection by predators. We examined the selection of nesting and brood-rearing habitats of sharp-tailed grouse at three spatial scales (landscape, patch, and site) in northeastern British Columbia using standard and conditional logistic regression models and an information–theoretic approach. At the patch and site scales, our results validate our predictions, as nesting females selected shrub–steppe habitats, greater shrub and grass cover, taller vegetation, and greater residual vegetation compared with random sites. Brood-rearing females selected for agricultural habitats during the early brood-rearing period (0–14 days), but did not show selection of any habitat type or site attribute during the late brood-rearing period (15–49 days). We suggest that the selection of shrub-dominated habitats by nesting females supports the hypothesis that females select sites and habitats that maximize concealment. We further suggest that selection of shrub-dominated habitat is occurring in response to changes in habitat conditions and availability, as natural grassland communities have diminished across the landscape.