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We revealed that the encapsulation of enzyme-immobilized silica particles in hollow-type spherical bacterial cellulose (HSBC) gels enables the use of the inside of HSBC gels as a reaction field. The encapsulation of horseradish peroxidase (HRP)-immobilized silica particles (Si-HRPs, particle size: 40–50 μm) within HSBC gels was performed by using a BC gelatinous membrane produced at the interface between Komagataeibacter xylinus suspension attached onto an alginate gel containing Si-HRPs and silicone oil. After the biosynthesis of the BC gelatinous membrane, formed from cellulose nanofiber networks, the alginate gel was removed via immersion in a phosphate-buffered solution. Si-HRP encapsulated HSBC gels were reproducibly produced using our method with a yield of over 90%. The pore size of the network structure of the BC gelatinous membrane was less than 1 μm, which is significantly smaller than the encapsulated Si-HRPs. Consequently, the encapsulated Si-HRPs could neither pass through the BC gelatinous membrane nor leak from the interior cavity of the HSBC gel. The activity of the encapsulated HRPs was detected using the 3,3′,5,5′-tetramethylbenzidine (TMB)-H2O2 system, demonstrating that this method can encapsulate the enzyme without inactivation. Since HSBC gels are composed of a network structure of biocompatible cellulose nanofibers, immune cells cannot enter the hollow interior, thus, the enzyme-immobilized particles encapsulated inside the HSBC gel are protected from immune-cell attacks. The encapsulation technique demonstrated in this study is expected to facilitate the delivery of enzymes and catalysts that are not originally present in the in vivo environment. [ABSTRACT FROM AUTHOR]

To reduce the risk of the adsorption of granular activated carbon in the gastrointestinal tract, we successfully produced a hollow-type spherical bacterial cellulose (HSBC) gel containing activated carbon with a particle size of 6 μm. In this study, the aim of which was to develop an effective formulation, we evaluated the stability of activated-carbon-encapsulating HSBC gels under various pH conditions. Activated-carbon-encapsulating HSBC gels (ACEGs) retained the activated carbon without leaking when subjected to agitation in acidic or basic environments. The saturated adsorption amount, calculated using the Langmuir adsorption isotherm, was affected by the target adsorbate and pH conditions. These results indicate that ACEGs can adsorb uremic toxins and their precursors similarly to conventional uremic toxin adsorbents while preventing direct contact between the encapsulated activated carbon and the gastrointestinal tract. Compared to powdered activated carbon, the ACEG is less likely to be adsorbed in the gastrointestinal tract. Therefore, the proposed ACEG is a promising new formulation that will contribute to the treatment of renal failure and improve patients' compliance with medication. [ABSTRACT FROM AUTHOR]

This review shows the importance of high-glycemic carbohydrates consumed together with protein in enhancing the exercise-induced muscle formation relative to timing of intake. Insulin, which increases in blood after glycemic carbohydrate ingestion, seems to effectively stimulate protein synthesis and inhibit protein degradation right after exercise rather than later. This presents a new aspect in nutrition: the importance of intake timing in addition to the composition and amount of nutrients. Key words: protein, exercise-induced muscle formation, insulin

The effects of elevated levels of amino acid and insulin availability on protein kinetics was analyzed in dogs with chronically fitted catheters during a treadmill exercise. Analysis of protein kinetics in dogs during exercise after the administration of amino acids and glucose indicated the presence of increased protein synthesis which induced a positive net protein balance. Furthermore, the timing of postexercise nutrient administration modulated the rate of skeletal muscle protein synthesis.

Branched-chain [Alpha]-keto acid dehydrogenase complex is the rate-limiting enzyme in the catabolism of branched-chain amino acids in skeletal muscle. It is suggested that activation of this enzyme in the muscle during exercise plays an important role in the increased oxidation of branched-chain amino acids in the muscle. Evidence suggests that branched-chain [Alpha]-keto acids, the substrates for the enzyme, regulate the activity state of the enzyme in the muscle during exercise through phosphorylation/dephosphorylation cycle of the enzyme protein. We propose a model for the mechanism of enzyme activation by exercise. In addition to this acute effect of exercise, we present evidence suggesting that exercise training modulates the enzyme activity and gene expression for the enzyme. Increases in the total activity as well as enzyme proteins by exercise training are suggested to be associated with mitochondrial biogenesis in the muscle. INDEXING KEY WORDS: branched-chain [Alpha]-keto acid dehydrogenase; branched-chain amino acids; exercise

The objectives of the present study were to examine the effects of dietary fats differing in fatty acid composition on diet-induced thermogenesis, sympathetic activity in brown adipose tissue and body fat accumulation in rats. Rats were meal-fed for 12 wk an isoenergetic diet based on lard, high oleic acid safflower oil, safflower oil or linseed oil, and norepinephrine turnover rates in brown adipose tissue were then estimated. Whole-body oxygen consumption after the meal indicated that diet-induced thermogenesis was significantly lower in rats fed the lard diet than in those fed the other diets. The norepinephrine turnover rate in the inter-scapular brown adipose tissue was also significantly lower in the lard diet group than in the other diet groups. The carcass fat content was significantly higher in the lard diet group than in the other diet groups, whereas the abdominal adipose tissue weights were the same in all diet groups. These results suggest that the intake of animal fats rich in saturated fatty acids, compared with the intake of vegetable oils rich in monounsaturated or polyunsaturated fatty acids, decreases diet-induced thermogenesis by a decline of sympathetic activity in brown adipose tissue, resulting in the promotion of body fat accumulation. INDEXING KEY WORDS: body composition; brown adipose tissue; dietary fats; sympathetic activity; rats

Northern and Southern blot analyses help measure the activities of various enzymes, mitochondrial cytochrome b mRNA and mitochondrial RNA to determine the influence of different periods of physical training on mitochondrial gene expression and replication in rat soleus muscle, which consists of slow-twitch fibers. All rats exhibit an increased oxidative capacity and mitochondrial gene expression in the muscle, while rats trained for longer periods only exhibit increased mitochondrial gene replication.

We compared the effects of dietary polydextrose with those of dietary fibers on the luminal pH and morphology of the large intestine in rats. In Experiment 1, animals were fed diets supplemented with two levels (5 and 10 g/100 g) of polydextrose or dietary fiber (cellulose or galactomannan derivatives) for 52 d. Polydextrose and galactomannan derivatives significantly lowered large intestinal pH and increased the cecal weight and surface area compared with cellulose. However, the thickness of the cecal muscular layer was significantly less in the polydextrose-fed groups than in the cellulose-fed groups. In Experiment 2, rats were fed either a fiber-free diet or a diet containing 5, 10 or 20 g/100 g polydextrose for 92 d. Dietary polydextrose significantly acidified the cecal contents and promoted cecal mucosal growth but thinned the cecal muscular layer. The shape of colonic mucosa of the group fed the 20 g/100 g polydextrose diet was clearly different from that of the group fed the fiber-free diet. These findings indicate that the effect of polydextrose on the morphology of the large intestine is different from the effect of dietary fibers.