The results of this study indicate that whole body metabolic and cardiovascular responses to 140 min of either steady state or variable intensity exercise at the same average intensity are similar, despite differences in skeletal muscle carbohydrate metabolism and recruitment
DOCUMENT
The metabolic syndrome (MetS) comprises cardiometabolic risk factors frequently found in individuals with obesity. Guidelines to prevent or reverse MetS suggest limiting fat intake, however, lowering carbohydrate intake has gained attention too. The aim for this review was to determine to what extent either weight loss, reduction in caloric intake, or changes in macronutrient intake contribute to improvement in markers of MetS in persons with obesity without cardiometabolic disease. A meta-analysis was performed across a spectrum of studies applying low-carbohydrate (LC) and low-fat (LF) diets. PubMed searches yielded 17 articles describing 12 separate intervention studies assessing changes in MetS markers of persons with obesity assigned to LC (<40% energy from carbohydrates) or LF (<30% energy from fat) diets. Both diets could lead to weight loss and improve markers of MetS. Meta-regression revealed that weight loss most efficaciously reduced fasting glucose levels independent of macronutrient intake at the end of the study. Actual carbohydrate intake and actual fat intake at the end of the study, but not the percent changes in intake of these macronutrients, improved diastolic blood pressure and circulating triglyceride levels, without an effect of weight loss. The homeostatic model assessment of insulin resistance improved with both diets, whereas high-density lipoprotein cholesterol only improved in the LC diet, both irrespective of aforementioned factors. Remarkably, changes in caloric intake did not play a primary role in altering MetS markers. Taken together, these data suggest that, beyond the general effects of the LC and LF diet categories to improve MetS markers, there are also specific roles for weight loss, LC and HF intake, but not reduced caloric intake, that improve markers of MetS irrespective of diet categorization. On the basis of the results from this meta-analysis, guidelines to prevent MetS may need to be re-evaluated.
DOCUMENT
High consumption of carbohydrates is linked to metabolic syndrome, possibly via the endogenous formation of advanced glycated end-products. Many Dutch elementary school children have a carbohydrate intake of >130g/day, the estimated minimum requirement. In this observational study, 126 Dutch elementary school children (5-12y of age) from two schools differing in frequency of gym lessons (2 or 5 times a week) were included. In all participants, height, weight, waist circumference, autofluorescence of skin glycated end-products (AGE-score), sports activity and carbohydrate consumption were recorded once. Sports activities in leisure time differentiated participants in ‘sportsmen’ and ‘non-sportsmen’. Carbohydrate intake and AGE score were positively associated in non-sportsmen (p<0.003), but negatively in sportsmen (p<0.002). In sportsmen, but not in non-sportsmen (p>0.50), a positive association was found (p<0.002) between carbohydrate intake and subject age. The intake of total carbohydrate and carbohydrates from juices and soft drinks was lower (p<0.001) at the Wassenberg School relative to the Alexander School. Based on waist to height ratio, >95% of the children had normal fat mass. No correlations were found between waist to height ratio or BMI and carbohydrate intake. Waist to height ratio was positively associated with BMI (p<0.001)) and subject age (p<0.001). Of all principal parameters, AGE score is most affected by being sportsmen or not (p<0.001). This study indicates that an increased intake of carbohydrates can be counteracted by sufficient physical activity (>2.5 hours per week). This implies that skin autofluorescence is a fast and non-invasive method to screen children for life style.
DOCUMENT
This paper descibes a study that shows that glycogen-lowering exercise, performed the evening before an exercise bout in combination with glycogen restriction leads to a reduction of the oxidation rate of ingested glucose during moderate-intensity exercise
DOCUMENT
1. An earlier study by our group revealed that the viscosity of faeces from patients with Crohn's disease is significantly lower than that of healthy subjects. This is due to low concentrations of a high-molecular-mass carbohydrate, probably of bacterial origin. The cause of this phenomenon might be the impaired barrier function of the gut mucosa. Low viscosity may allow close contact of intestinal contents (bacterial products and toxins) with the intestinal wall. This could play a role in the maintenance of the disease.2. The first aim of this study was to investigate the high-molecular-mass carbohydrate fraction, responsible for viscosity, in detail. We also tried (in a pilot study) to raise the intestinal viscosity of patients with Crohn's disease with the undegradable food additive hydroxypropylcellulose (E463), in an attempt to alleviate clinical symptoms.3. The high-molecular-mass fraction (>300 kDa) responsible for faecal viscosity was sensitive to lysozyme and contained high levels of muramic acid. It was concluded that this material consisted mainly of peptidoglycan polysaccharides and was consequently of bacterial origin. The muramic acid in material from patients with Crohn's disease was 7.5 (1.5-13.9)%, which was less than in healthy subjects [11.4 (8.5-24.1)%; P=0.0004]. Furthermore, viscosity in material from patients with Crohn's disease was found to be half [14.9 (1.0-33.6) cP] of that found in healthy subjects [35.0 (2.7-90.7) cP; P=0.004].4.A daily dose of 1 g of hydroxypropylcellulose caused an increase in faecal viscosity in patients with Crohn's disease (from 1.4 to 2.3 cP) and in healthy subjects (from 4.9 to 7.5 cP). Faecal consistency improved in patients with Crohn's disease (from watery and loose to formed) and the defecation frequency decreased from 3-4 to about 2 times a day. No changes in defecation patterns were found in healthy subjects.5. These data indicate that the high-molecular-mass fraction that is responsible for faecal viscosity is peptidoglycan. Furthermore, a daily dose of a hydroxypropylcellulose solution to increase the viscosity of the intestinal contents of patients with Crohn's disease might be beneficial. This approach merits further study.
LINK
For the future circular economy, renewable carbon feedstocks manifest considerable promise for synthesizing sustainable and biodegradable polyhydroxyalkanoate (PHA). In this study, 16 wt% and 30 wt% PHA (cell dry weight) are respectively produced by thermophilic Caldimonas thermodepolymerans from beechwood xylan and wheat arabinoxylan as the sole carbon source. Moreover, an in silico study of the potential xylan-degrading proteins was conducted using proteome sequencing and CAZyme specialized bioinformatic tools. This study demonstrates the feasibility of utilizing complex polysaccharide substrates for PHA biosynthesis, thereby potentially eliminate additional processing steps and reducing overall production costs for sustainable plastic.
MULTIFILE
A number of novel nonionic bolaform amphiphiles with nonidentical aldityl head groups, 1-(1-deoxy-D-galactitol-1-ylamino)-6-(1-deoxy-D-glucitol-1-ylamino)hexane, 1-(1-deoxy-D-mannitol-1-ylamino)-6-(1-deoxy-D-glucitol-1-ylamino)hexane, and 1-(1-deoxy-D-galactitol-1-ylamino)-6-(1-deoxy-D-mannitol-1-ylamino)hexane were synthesized by two successive reductive aminations involving 1,6-diaminohexane (1) and the appropriate D-aldohexoses (D-glucose, D-mannose, and D-galactose) using 5% Pd on carbon as the catalyst. Typical reaction conditions were 40 degrees C, 4MPa hydrogen and a reaction time of 4.5 h. The compounds were isolated as white solids in yields ranging from 39% to 72%. The intermediate aminoalditols, 1-(1-deoxy-D-glucitol-1-ylamino)-6-aminohexane and 1-(1-deoxy-D-galactitol-1-ylamino)-6-aminohexane were obtained as off-white solids in 80-85% yield. The bolaform amphiphiles containing 1-deoxy-D-glucitol head group(s) showed markedly lower melting points than the compounds with the 1-deoxy-D-mannitol and 1-deoxy-D-galactitol head groups, due to the presence of 1,3-syn interactions within the carbohydrate moiety. The novel bolaform compounds are potential starting materials for the synthesis of a broad range of gemini surfactants with nonidentical, carbohydrate-based head groups.
DOCUMENT
1. Diets that maximise life span often differ from diets that maximise reproduction. Animals have therefore evolved advanced foraging strategies to acquire optimal nutrition and maximise their fitness. The free-living adult females of parasitoid wasps (Hymenoptera) need to balance their search for hosts to reproduce and for carbohydrate resources to feed. 2. Honeydew, excreted by phloem-feeding insects, presents a widely available carbohydrate source in nature that can benefit natural enemies of honeydew-producing insects. However, the effects of variation in honeydew on organisms in the fourth trophic level, such as hyperparasitoids, are not yet understood. 3. This study examined how five different honeydew types influence longevity and fecundity of four hyperparasitoid taxa. Asaphes spp. (Pteromalidae) and Dendrocerus spp. (Megaspilidae) are secondary parasitoids of aphid parasitoids and are thus associated with honeydew-producing insects. Gelis agilis and Acrolyta nens (both Ichneumonidae) are secondary parasitoids of species that do not use honeydew-producing hosts. 4. Most honeydew types had a positive or neutral effect on life span and fecundity of hyperparasitoids compared with controls without honeydew, although negative effects were also found for both aphid hyperparasitoids. Honeydew produced by aphids feeding on sweet pepper plants was most beneficial for all hyperparasitoid taxa, which can partially be explained by the high amount of honeydew, but also by the composition of dietary sugars in these honeydew types. 5. The findings of this study underline the value of aphid honeydew as a carbohydrate resource for fourth-trophic-level organisms, not only those associated with honeydew-producing insects but also 'interlopers' without such a natural association.
LINK
The catalytic oxidation of potato starch by [MnIV2 (μ-O)3(tmtacn)2][H2O](CH3COO)2 (Mncat, with tmtacn =1,4,7-trimethyl-1,4,7-triazacyclononane) with H2O2, was recently introduced as a promising alternative to ubiquitous sodium hypochlorite (NaOCl). Here, we report an in-depth investigation into interactions of the catalyst with the starch granule. Pitted starches obtained by pre-treatment with high-frequency ultrasound (HFUS) were shown to result in a uniquely homogeneous oxidation. To study this further, fractionation of oxidised potato starch was done which showed a preference for the oxidation of smaller granules with a higher relative surface area. This result was corroborated by chemical surface gelatinisation of fractionated granules. These studies showed that the inside of the granules was oxidised, but that Mncat had a moderate preference for oxidation of the periphery. Together, these results allow for a better understanding of oxidation of starch by Mncat and how it differs from NaOCl oxidation making further optimisation of the process possible.
DOCUMENT
This research article shows that a high intensity exercise program compared to a low intensity exercise program of the same session duration and frequency, increases insulin sensitivity to a larger extend in healthy subjects. It also shows that the short insulin tolerance test can be used to detect differences in insulin sensitivity in intervention studies.
LINK
