Simultaneous delivery of antibiotics neomycin and ampicillin in drinking water inhibits fermentation of resistant starch in rats.

SCOPE: Antibiotics ampicillin 1 g/L and neomycin 0.5 g/L were added to drinking water before or during feeding of resistant starch (RS) to rats to inhibit fermentation. METHODS AND RESULTS: In a preliminary study, antibiotics and no RS were given prior to rats receiving a transplant of cecal contents via gavage from donor rats fed RS (without antibiotics) or a water gavage before feeding resistant starch to both groups. Antibiotics given prior to feeding RS did not prevent later fermentation of RS regardless of either type of gavage. In the second study, antibiotics were given simultaneously with feeding of RS. This resulted in inhibition of fermentation of RS with cecal contents pH >8 and low amounts of acetate and butyrate. Rats treated with antibiotics had reduced Bifidobacteria spp., but similar Bacteroides spp. to control groups to reduce acetate and butyrate and preserve the production of propionate. Despite reduced fermentation, rats given antibiotics had increased glucagon-like peptide 1 (GLP-1) and cecum size, measures that are usually associated with fermentation. CONCLUSIONS: A simultaneous delivery of antibiotics inhibited fermentation of RS. However, increased GLP-1 and cecum size would be confounding effects in assessing the mechanism for beneficial effects of dietary RS by knocking out fermentation.

Obese ZDF rats fermented resistant starch with effects on gut microbiota but no reduction in abdominal fat.

SCOPE: To determine if whole-grain (WG) flour with resistant starch (RS) will produce greater fermentation than isolated RS in obese Zucker Diabetic Fatty (ZDF) rats, and whether greater fermentation results in different microbiota, reduced abdominal fat, and increased insulin sensitivity. METHODS AND RESULTS: This study utilized four groups fed diets made with either isolated digestible control starch, WG control flour (6.9% RS), isolated RS-rich corn starch (25% RS), or WG corn flour (25% RS). ZDF rats fermented RS and RS-rich WG flour to greatest extent among groups. High-RS groups had increased serum glucagon-like peptide 1 (GLP-1) active. Feeding isolated RS showed greater Bacteroidetes to Firmicutes phyla among groups, and rats consuming low RS diets possessed more bacteria in Lactobacillus genus. However, no differences in abdominal fat were observed, but rats with isolated RS had greatest insulin sensitivity among groups. CONCLUSIONS: Data demonstrated ZDF rats (i) possess a microbiota that fermented RS, and (ii) WG high-RS fermented better than purified RS. However, fermentation and microbiota changes did not translate into reduced abdominal fat. The defective leptin receptor may limit ZDF rats from responding to increased GLP-1 and different microbiota for reducing abdominal fat, but did not prevent improved insulin sensitivity.

Observation on the ultrastructure morphology of HeLa cells treated with ethanol: Statistical analysis.

It is estimated that 5.9% of all human deaths are attributable to alcohol consumption and that the harmful use of ethanol ranks among the top five risk factors for causing disease, disability, and death worldwide. Ethanol is known to disrupt phospholipid packing and promote membrane hemifusion at lipid bilayers. With the exception of mitochondria involved in hormone synthesis, the sterol content of mitochondrial membranes is low. As membranes that are low in cholesterol have increased membrane fluidity and are the most easily disordered by ethanol, we hypothesize that mitochondria are sensitive targets for ethanol damage. HeLa cells were exposed to 50 mM ethanol and the direct effects of ethanol on cellular ultrastructure were examined utilizing transmission electron microscopy. Our ultramicroscopic analysis revealed that cells exposed to ethanol harbor fewer incidence of apoptotic morphology; however, significant alterations to mitochondria and to nuclei occurred. We observed statistical increases in the amount of irregular cells and cells with multiple nuclei, nuclei harboring indentations, and nuclei with multiple nucleolus-like bodies. Indeed, our analysis revealed that mitochondrial damage is the most extensive type of cellular damage. Rupturing of cristae was the most prominent damage followed by mitochondrial swelling. Ethanol exposure also resulted in increased amounts of mitochondrial rupturing, organelles with linked membranes, and mitochondria localizing to indentations of nuclear membranes. We theorize that these alterations could contribute to cellular defects in oxidative phosphorylation and, by extension, the inability to generate regular levels of cellular adenosine triphosphate.

Induction of Energy Expenditure by Sitagliptin Is Dependent on GLP-1 Receptor.

Sitagliptin (SG) increases serum GLP-1 (Glucagon-like peptide-1) through inhibition of the hormone degradation. Resistant starch (RS) induces GLP-1 expression by stimulating L-cells in the intestine. Sitagliptin and resistant starch may have a synergistic interaction in the induction of GLP-1. This possibility was tested in current study in a mouse model of type 2 diabetes. Hyperglycemia was induced in the diet-induced obese mice by a signal injection of streptozotocin (STZ). Sitagliptin (0.4g/100g diet) was tested in the mice (n = 55) with dietary RS (HAM-RS2) at three dosages (0, 15, or 28g/100g diet). Energy and glucose metabolism were monitored in the evaluation of synergistic activity, and GLP-1 activity was determined in the GLP-1 receptor knockout (KO) mice. In the wild type mice, body weight and adiposity were reduced by sitagliptin, which was enhanced by RS (28g). Serum GLP-1 was induced and energy expenditure was enhanced by sitagliptin. Fasting glucose, insulin, and leptin levels were decreased by sitagliptin. The sitagliptin effects were lost in the KO mice (n = 25) although induction of serum GLP-1 by sitagliptin was even stronger in KO mice. The data suggests that sitagliptin is able to reduce adiposity and insulin resistance through induction of energy expenditure. The effect of sitagliptin is partially enhanced by RS. GLP-1 receptor may regulate serum GLP-1 by facilitating the hormone clearance.

Radial wood allocation in Schizolobium parahyba.

PREMISE OF THE STUDY: Pioneer species of tropical trees allocate wood specific gravity (SG) differently across the radius. Some species exhibit relatively uniform, low SG wood, whereas many others exhibit linear increases in SG across the radius. Here, we measured changes in SG across the radius of Schizolobium parahyba (Fabaceae-Caesalpinioideae), a wide-ranging, neotropical pioneer, used extensively in land reclamation and forest restoration in Brazil. METHODS: Pith-to-bark radial wood cores were extracted with increment borers from 42 trees at five sites, in Central and South America. Cores were cut into 1-cm segments whose specific gravities were determined and analyzed via linear and nonlinear regression. Wood specific gravity, very low initially at 0.15-0.20, doubled or tripled across the tree radius to 0.45-0.65 for large adults. KEY RESULTS: Unlike linear increases in other tropical pioneers, the increases in Schizolobium were nonlinear (convex up). At one site with even-aged trees, the magnitude of the radial increase was similar in all trees, despite a 4-fold difference in diameter among trees, implying that the radial increases in Schizolobium were regulated by tree age, not by tree size. CONCLUSIONS: This unique pattern of development should provide an extended period of growth when SG is low, facilitating hyper-extension of the bole, at some risk of structural failure. Later in growth, the SG rate of increase accelerates, reinforcing what was a precarious bole. Overall, these results suggest a third model for xylem allocation in tropical trees, a model that may be associated with monopodial stem development and limited life span.

A cafeteria-based tasting program increased liking of fruits and vegetables by lower, middle and upper elementary school-age children.

This study aimed to increase 1st, 3rd, and 5th grade children's liking for fruits and vegetables by offering repeated opportunities to taste selected items. Tastes of four fruits or four vegetables were offered to children (51% boys; 32% 1st graders and 34% 3rd graders) on alternate weeks for 8 weeks. Two-week follow-up tastings occurred 4 months and 10 months post-intervention. Children who began the program disliking the targeted fruits and vegetables improved liking for all items after 8 weeks and maintained higher scores at both follow-up assessments. Grade and gender differences in liking were observed but were not consistent at each time point.

Repeated taste exposure increases liking for vegetables by low-income elementary school children.

Children's food preferences play a major role in their food choices and consumption. The objective of the present study was to examine if repeated tastings of selected vegetables in a school setting increased children's liking of these items. A total of 360 fourth- and fifth-grade students attending four low-income, public elementary schools in southeastern Louisiana volunteered to participate. During the spring of 2008, children were offered a taste of carrots, peas, tomatoes, and bell peppers once a week for 10 weeks. At each tasting session children recorded whether they swallowed each of the vegetables, spit it into the napkin, or did not put it in their mouth and indicated their liking for each vegetable using a Likert-type response scale. Approximately one-half of the children tasted eight of ten times during the program (46.5% for those who began disliking and 68.5% for those who began liking the vegetables). Proc Glimmix analyses indicated that for children who began the program disliking the vegetables, repeated tasting improved liking scores for carrots, peas, and tomatoes; liking for bell peppers did not change. The number of children who reported liking or liking a lot for previously disliked vegetables was greater after eight or nine taste exposures. Repeated tasting of less-liked vegetables by children in a cafeteria-based setting is a strategy to promote liking of these items and is effective in approximately half of the participants.

Contributors to fatigue resistance of the hamstrings and quadriceps in cerebral palsy.

BACKGROUND: The purpose of this study was to elucidate relationships between quadriceps and hamstrings voluntary muscle fatigue and upper motor lesion impairments in cerebral palsy in order to gain a better understanding of their contribution to the observed fatigue resistance. METHODS: Seventeen ambulatory subjects with cerebral palsy (mean age: 17.0, SD=4.8 years) were recruited. Quantitative measures of strength, spasticity, cocontraction, and stiffness for both muscle groups were collected on an isokinetic dynamometer and entered in a factor analysis. The resulting factors were used as independent variables in a multiple regression analysis with quadriceps and hamstrings fatigue as dependent variables. FINDINGS: Five independent factors explained 90% of the variance. In order of loadings, higher hamstring cocontraction and spasticity and lower hamstring strength were associated with lower levels of hamstring fatigue. Higher quadriceps cocontraction and lower quadriceps strength were the most predictive of lower levels of quadriceps fatigue. INTERPRETATION: Greater motor impairments of the agonist muscle, particularly cocontraction, spasticity, and weakness, were associated with lower rates of muscle fatigue of the same muscle during performance of a voluntary fatigue protocol for the hamstrings and quadriceps. Muscles are highly adaptable; therefore, the results of this study suggest that the observed fatigue resistance may be due to the effect of the primary neural insult on motor unit recruitment and rate modulation or the result of secondary adaptations to spasticity, weakness, or excessive cocontraction.

"Smart Bodies" school wellness program increased children's knowledge of healthy nutrition practices and self-efficacy to consume fruit and vegetables.

Diets rich in fruit and vegetables are important for long-term health yet children frequently do not like these foods. The "Smart Bodies" school wellness program sought to increase children's knowledge of healthy nutritional practices, improve psychosocial variables associated with eating fruit and vegetables, and develop preferences for these foods. A randomized controlled intervention trial was conducted in 14 low-income, urban, public elementary schools (seven pairs). Data from 278 fourth and 282 fifth graders (234 boys, 326 girls; 82% Black, 10% White, 1% Hispanic, 5% Asian, 2% Other) were examined using multi-level modeling. The 12-week intervention program included participation in an interactive wellness exhibit and a classroom curriculum that emphasized consumption of fruit and vegetables. After the intervention, children that participated in the "Smart Bodies" program had greater nutrition knowledge and expressed more confidence that they could eat fruit instead of a favorite dessert, drink fruit juice and consume the recommended number of fruits and vegetables servings each day. Preferences for fruit and vegetables did not change as a result of participating in the program. These findings demonstrate that the "Smart Bodies" school-based wellness intervention positively impacted children's nutrition knowledge and psychosocial variables associated with consuming fruit and vegetables.

Fatigue resistance during a voluntary performance task is associated with lower levels of mobility in cerebral palsy.

OBJECTIVES: To investigate muscle fatigue of the knee flexors and extensors in people with cerebral palsy (CP) compared with those without motor disability during performance of a voluntary fatigue protocol and to investigate the relationship with functional mobility. DESIGN: A case-control study. SETTING: A biomechanics laboratory. PARTICIPANTS: Ambulatory subjects with CP (n=18; mean age, 17.5 y) in Gross Motor Function Classification System (GMFCS) levels I, II, and III and a comparison group of age-matched subjects (n=16) without motor disability (mean age, 16.6 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The voluntary muscle fatigue protocol consisted of concentric knee flexion and extension at 60 degrees a second for 35 repetitions on an isokinetic dynamometer. Peak torque for each repetition was normalized by the maximum peak torque value. Muscle fatigue was calculated as the rate of decline in normalized peak torque across all repetitions, represented by the slope of the linear regression. Self-selected and fast gait velocities were measured as well as the Pediatric Outcomes Data Collection Instrument (PODCI). RESULTS: Greater fatigability (slope) was observed in the comparison group for both knee flexors and extensors than in the group with CP. Within CP, lower knee extensor fatigue (slope) was associated with lower functioning GMFCS levels and lower levels of activity and participation as measured by the PODCI transfers and basic mobility. CONCLUSIONS: Even after adjusting for maximum peak torque, the knee flexors and extensors of participants with CP were observed to be less fatigable than age-matched peers without motor disability. The lower rate of muscle fatigue was also associated with lower functional mobility in CP. These results may be related to strength or activation differences and/or muscle property alterations. Future investigations are warranted.

Time course of improved flow-mediated dilation after short-term exercise training.

PURPOSE: The purpose was to determine the influence of a unilateral localized short-term handgrip training protocol on brachial artery flow-mediated dilation (BAFMD) and to examine the time course of such changes. METHODS: Fourteen healthy males (age: 26 +/- 5.7 yr) underwent high-resolution ultrasonographic brachial artery assessments before (V1), during (V2-V7), and at the end of 4 wk (V8) of 60% maximal voluntary contraction handgrip training (20 min.d-1, 5 d.wk-1) of the nondominant arm. RESULTS: Before training resting diameters were similar between the trained (nondominant) and untrained (dominant) arms. A 2 (trained and untrained arms) x 2 (V1 and V8) repeated measure ANOVA revealed a significant main (P = 0.02 and P = 0.03) and interaction effect (P = 0.05 and P = 0.01) for the percent and absolute change in BAFMD. BAFMD improved 62% and 70%, respectively from V1 to V8, for the percent and absolute change. Subsequent linear orthogonal polynomial contrasts indicate both the percent and absolute change in BAFMD were statistically different at V2 (end of week 1 and 4 training days) from V1. These unilateral changes were not accompanied by changes in resting artery diameter, hemodynamic measures, hematological markers, and indices of heart rate variability suggesting the change may be locally mediated. CONCLUSIONS: This study shows a localized short-term exercise-training program resulted in significant improvements in BAFMD in the trained arm compared with the untrained arm and suggests this occurred after only 4 d of training.

Stability and reproducibility of brachial artery flow-mediated dilation.

PURPOSE: Brachial artery flow-mediated dilation (BAFMD) is a noninvasive technique, which has been suggested as a potential means of identifying patients with early atherosclerosis and therefore has enormous clinical appeal. Despite this, the stability and reproducibility of this technique are not yet clear. Therefore, the purpose of this study was to establish the stability and reproducibility of BAFMD after 5 min of forearm occlusion and to produce power calculations to aid in clinical trial design. METHODS: Twenty-six healthy volunteers underwent high-resolution ultrasonographic brachial artery assessments before, during, and after 5 min of forearm occlusion. The study design involved three scans on 2 d, performed by two ultrasonographers and analyzed by two readers. All subjects were tested between 7 and 11 a.m. after refraining from food and exercise. The nondominant arms were scanned, in longitudinal view, approximately 4 cm proximal to the olecranon process, in the anterior/medial plane. Blood draws were performed on each visit. The SAS MIXED restricted maximum likelihood (REML) procedure for an unbalanced design was used to calculate variance components and provide power calculations. RESULTS: Average baseline artery diameter for all studies was 3.48 +/- 0.53 mm. This increased to 3.71 +/- 0.57 mm (6.58 +/- 4.15%) at peak dilation. Intraclass correlation coefficients (ICCC) for days, testers, and readers were 0.92, 0.94, and 0.90, respectively. To detect a difference in vasoreactivity of 60% (two-tailed), e.g., 5% vasodilation versus 8% vasodilation, at 90% power, 23 and 10 subjects would be required for cross-sectional and pre-post designs, respectively. CONCLUSIONS: These data indicate adequate stability and reproducibility of the BAFMD technique under controlled conditions. Additionally, BAFMD appears useful to differentiate between groups, although its prognostic value for the examination of individuals is unclear.