Comparative nutritional value for amino acids,oligopeptides and soybean protein

In recent years our view on the absorption of protein digestion products has undergone a radical change. We now believe that intralumen hydrolysis of intake proteins to free amino acids is only partial. It has thus been hypothesized that partial protein hydrolysates or oligopeptide mixtures are nutritionally superior to corresponding amino acid mixtures. With this consideration for a background, we developed a sophisticated technique of protease-catalyzed modification of soy protein to produce enzymatically modified proteins (EMP) having different levels of covalently attached methionine. We also carried out feeding tests with protein-malnourished rats, with the result that for their recovery from a state of malnutrition, an EMP containing peptide-bound methionine at 3% was significantly more effective than the corresponding amino acid mixture and even the soy protein itself. Discussions stress the importance of applying such a technique to production of an oligopeptide rather than a free amino acid nitrogen source as a foodstuff for therapeutic use.     

Biocompatibility of Clearfil Liner Bond 2 and Clearfil AP-X system on nonexposed and exposed primate teeth

Females, especially older women, historically have been excluded from coronary heart disease (CHD) studies. The PrimeTime program was a randomized clinical trial designed to study the effects of a comprehensive lifestyle management program (very low-fat vegetarian diet, smoking cessation, stress-management training, moderate exercise, and group support) on changes in behavioral risk factors among postmenopausal women with CHD. The study also explored program effects on four psychosocial clusters: coping with stress, distress, social support, and self-efficacy. The program produced significant behavioral improvements in 4- and 12-months adherence to diet, physical activity, and stress-management in the PrimeTime women compared to the Usual Care (UC) group. In addition, the PrimeTime participants demonstrated improvements relative to UC on psychosocial measures of self-efficacy, perceived social support, and ability to cope with stress. Strengths and weaknesses of the study, and implications for future research are discussed.     

A study for the biological CO2 fixation and utilization system

ECVAM was established to play a leading role at the European level in the independent evaluation of the reliability and relevance of test methods and testing strategies for specific purposes through research on advanced methods and new test development and validation, so that chemicals and products of various kinds, including medicines, vaccines, medical devices, cosmetics, household products and agricultural products, can be manufactured, transported and used more economically and more safely, whilst the current relevance on animal test procedures is progressively reduced. Nowhere is this activity more necessary than in the field of immunotoxicology, where we know that chemicals and products of many kinds have the potential to stimulate, modulate or suppress the induction or expression of various types of immune responses. The problem is to effectively evaluate the potency of these effectors, and, since the available information is currently based on rather qualitative animal tests, to evaluate the true relevance of this knowledge and apply it intelligently in risk assessment processes which will protect human beings without unnecessarily limiting the development and use of materials which otherwise have economic, health and social benefits. The way forward must depend on the following: (a) a better understanding of immunotoxicological processes, based on a sounder understanding of the immune system itself (and of its network of control systems and interrelationships with other body systems); (b) The use of in vitro (not in vivo) systems based on human (not animal) cells and tissues; (c) integrated and tiered testing strategies, incorporating QSAR, as well as in vitro approaches; (d) taking advantage of the use of cells or factors from humans who have been exposed to potential immunotoxins, be this voluntarily, occupationally, environmentally or by accident; and (e) the recognition that virtually everything will effect one or more aspects of the immune system at some dose level and, in some circumstances, deciding when such effects are relevant, is the key to immunotoxicity testing. Some current ECVAM-sponsored work and activities at ECVAM are described.     

Increase of Serum Cholesterol Levels by Heat-Moisture-Treated High-Amylose Cornstarch in Rats Fed a High-Cholesterol Diet

The effects of four cornstarches containing various contents of resistant starch on serum and liver cholesterol levels in rats fed a high-cholesterol diet were investigated. Male Sprague Dawley rats (aged 4 weeks) were divided into four groups (n = 7) and fed high-cholesterol diets containing 15% of cornstarch (CS), heat-moisture-treated CS (HCS), high-amylose CS (HA), or heat-moisture-treated HA (HHA) for 21 days. The results showed that the serum and hepatic level of total cholesterol, LDL-cholesterol, and triglyceride in rats of the HHA group and their arteriosclerosis index were significantly higher, suggesting that HHA increases the risk of arteriosclerosis under a high-cholesterol dietary condition. No significant between-group differences were noted in the levels of plasma mevalonic acid and hepatic HMG-CoA reductase mRNA, whereas fecal cholesterol excretion was significantly higher in the HHA group, indicating that the elevation of the serum and liver cholesterol levels was not due to the promotion of liver cholesterol synthesis and cholesterol absorption in the intestine.     

Optimization for removal of ruthenium from nitric acid solution by volatilizing with electrochemical oxidation

Ruthenium is a major fission product element among the platinum group elements (PGEs) in high-level liquid waste (HLLW). Ru tetra-oxide, RuO₄, has high vapor pressure, which is high enough to be run off from its solution even at room temperature. Electrochemical oxidation method, to oxidize nitrosyl ruthenium to the tetra-oxide and then to remove ruthenium from liquid phase to gas phase, was studied to separate Ru from the HLLW. The advantage of this method requires neither additional reagents nor adjustment its valency before the oxidation and disadvantage is necessity of long time for oxidation. In order to improve oxidation rate, we carried out the experiments to clarify the effects following fundamental conditions to the electrochemical oxidation, which are (a) electrolyte temperature, (b) presence of promoter elements, (c) evaporation or reflux of condensed phase, and (d) using or not using of diaphragm at counter electrode. We found the fast oxidation conditions as follows: (1) higher temperature; 95°C, (2) Ce coexistence; 3000 ppm; and (3) usage of a diaphragm for counter electrode. However, evaporation or reflux conditions did not directly affect the electrochemical oxidation efficiency.     

Characteristics of competitive adsorption between 2-methylisoborneol and natural organic matter on superfine and conventionally sized powdered activated carbons

When treating water with activated carbon, natural organic matter (NOM) is not only a target for adsorptive removal but also an inhibitory substance that reduces the removal efficiency of trace compounds, such as 2-methylisoborneol (MIB), through adsorption competition. Recently, superfine (submicron-sized) activated carbon (SPAC) was developed by wet-milling commercially available powdered activated carbon (PAC) to a smaller particle size. It was reported that SPAC has a larger NOM adsorption capacity than PAC because NOM mainly adsorbs close to the external adsorbent particle surface (shell adsorption mechanism). Thus, SPAC with its larger specific external surface area can adsorb more NOM than PAC. The effect of higher NOM uptake on the adsorptive removal of MIB has, however, not been investigated. Results of this study show that adsorption competition between NOM and MIB did not increase when NOM uptake increased due to carbon size reduction; i.e., the increased NOM uptake by SPAC did not result in a decrease in MIB adsorption capacity beyond that obtained as a result of NOM adsorption by PAC. A simple estimation method for determining the adsorbed amount of competing NOM (NOM that reduces MIB adsorption) is presented based on the simplified equivalent background compound (EBC) method. Furthermore, the mechanism of adsorption competition is discussed based on results obtained with the simplified EBC method and the shell adsorption mechanism. Competing NOM, which likely comprises a small portion of NOM, adsorbs in internal pores of activated carbon particles as MIB does, thereby reducing the MIB adsorption capacity to a similar extent regardless of adsorbent particle size. SPAC application can be advantageous because enhanced NOM removal does not translate into less effective removal of MIB. Molecular size distribution data of NOM suggest that the competing NOM has a molecular weight similar to that of the target compound.     

Synergistic effect of high hydrostatic pressure treatment and food additives on the inactivation of Salmonella enteritidis

The synergistic effect of high hydrostatic pressure (HHP) treatment and food additives (FAs) on the inactivation of Salmonella enteritidis was investigated. At 1% concentrations, all of the FAs tested showed significant synergistic effects, and 9 of 30 FAs showed strong synergistic effects. Citric acid, adipic acid, C8-sugarester, C10-sugarester, tannin, nisin, wasabi extract, ε-polylysine, and protamine each showed a strong inactivation effect when administered alone at the 1% level. In the HHP treatment at 250 MPa for 30 min, the minimum effective concentrations of C8-sugarester, C10-sugarester, and protamine were 0.25, 0.125, and 0.06%, respectively. These results indicate that some FAs are useful for increasing the inactivation ratio of S. enteritidis in HHP treatment.     

Characteristics and structural change of layered polysilane (Si6H6) anode for lithium ion batteries

Layered polysilane (Si₆H₆) has a graphite-like structure with higher capacity than crystalline silicon. The rate of increase of the thickness of a layered polysilane electrode after 10 charge-discharge cycles was smaller than that for a Si powder electrode, although the layered polysilane electrode has higher capacity. The structural changes of electrochemically lithiated and delithiated layered polysilane at room temperature were studied using scanning electron microscopy, X-ray diffraction and Raman spectroscopy. Layered polysilane became amorphous by insertion of lithium to 0 V, whereas insertion of lithium into crystalline silicon produces Li₁₅Si_4. Layered polysilane maintained an amorphous state during lithium insertion and deinsertion, whereas silicon changed between Li₁₅Si₄ and amorphous Li_xSi, which explains the smaller volume change of a layered polysilane electrode compared with a Si powder electrode.