Changes in caffeic acid derivatives in sweet potato (Ipomoea batatas L.) during cooking and processing

There was an obvious decrease in caffeic acid derivatives during the boiling of cube-shaped blocks of sweet potatoes. They also decreased in a mixture of freeze-dried sweet-potato powder and water maintained at room temperature. Ascorbic acid prevented the decrease, supporting the occurrence of an enzyme reaction with polyphenol oxidase (PPO). 5-O-Caffeoylquinic acid (5-CQA, "3-O-caffeoylquinic acid" as a trivial name) and 3,5-di-O-caffeoylquinic acid (3,5-CQA), major phenolic compounds of sweet potato, did not change when they were separately heated in boiling water. When the mixture of powdered sweet potato and water was heated at 100 degrees C, there was only a negligible decrease in the total amount of phenolic compounds, and portions of 5-CQA and 3,5-CQA were found to be isomerized to 3-CQA, 4-CQA, 3,4-CQA, and 4,5-CQA. The content and composition of the phenolic compounds in sweet potatoes differed between fresh and long-stored ones, as did their response to heating.     

Oxidative stress and lipid mediators induced in alveolar macrophages by ultrafine particles

In ambient aerosols, ultrafine particles (UFP) and their agglomerates are considered to be major factors contributing to adverse health effects. Reactivity of agglomerated UFP of elemental carbon (EC), Printex 90, Printex G, and diesel exhaust particles (DEP) was evaluated by the capacity of particles to oxidize methionine in a cell-free in vitro system for determination of their innate oxidative potential and by alveolar macrophages (AMs) to determine production of arachidonic acid (AA), including formation of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), reactive oxygen species (ROS), and oxidative stress marker 8-isoprostane. EC exhibiting high oxidative potential induced generation of AA, PGE2, LTB4, and 8-isoprostane in canine and human AMs. Printex 90, Printex G, and DEP, showing low oxidative capacity, still induced formation of AA and PGE2, but not that of LTB4 or 8-isoprostane. Aging of EC lowered oxidative potential while still inducing production of AA and PGE2 but not that of LTB4 and 8-isoprostane. Cellular ROS production was stimulated by all particles independent of oxidative potential. Particle-induced formation of AA metabolites and ROS was dependent on mitogen-activated protein kinase kinase 1 activation of cytosolic phospholipase A2 (cPLA2) as shown by inhibitor studies. In conclusion, cPLA2, PGE2, and ROS formation was activated by all particle types, whereas LTB4 production and 8-isoprostane were strongly dependent on particles' oxidative potential. Physical and chemical parameters of particle surface correlated with oxidative potential and stimulation of AM PGE2 and 8-isoprostane production.     

The kinetics of in vivo priming of CD4 and CD8 T cells by dendritic/tumor fusion cells in MUC1-transgenic mice

Previous work has demonstrated that dendritic/tumor fusion cells induce potent antitumor immune responses in vivo and in vitro. However, little is known about the migration and homing of fusion cells after s.c. injection or the kinetics of CD4+ and CD8+ T cell activation. In the present study, fluorescence-labeled dendritic/MUC1-positive tumor fusion cells (FC/MUC1) were injected s.c. into MUC1-transgenic mice. The FC/MUC1 migrated to draining lymph nodes and were closely associated with T cells in a pattern comparable with that of unfused dendritic cells. Immunization of MUC1-transgenic mice with FC/MUC1 resulted in proliferation of T cells and induced MUC1-specific CD8+ CTL. Moreover, CD4+ T cells activated by FC/MUC1 were multifunctional effectors that produced IL-2, IFN-gamma, IL-4, and IL-10. These findings indicate that both CD4+ and CD8+ T cells can be primed in vivo by FC/MUC1 immunization.     

Modeling associative learning with generalization for a case of warning signals

Animals associative learning plays a crucial role in many intraspecific or interspecific interactions, involving an animals use of information on its interacting counterparts. Here, we present a theoretical model that captures the basic features of an animals associative learning, which may involve generalization, for a simplest case of warning signals. Specifically, we derive formulae for the average level of associative memory as functions of a few parameters that reflect the population density of prey, predators efficiency of prey detection, and the properties of predators associative learning, including generalization and memory decay. This average level of associative memory is of central importance in determining preys fitness and, thus, the evolution of warning signals (i.e. aposematism). The derived formula also shows that another species with similar signal enhances the fitness of an aposematic species of concern as long as their signal is similar enough for generalization to occur. The model developed here can be extended to more complicated cases and the basic idea can be applied to modeling other interactions involving associative learning with generalization.     

Maturation of fermented rice-koji miso can be monitored by an increase in fatty acid ethyl ester

A mixture of steamed soybean and boiled rice with seeded Aspergillus oryzae was naturally fermented without addition of yeasts or Lactobacilli, and kept matured for 12 months at room temperature. Chemical analysis of this rice-koji miso sample for lipid changes during maturation showed that triacylglycerol was gradually decomposed into free fatty acid, with distinct formation of fatty acid ethyl ester which, six months after the start of fermentation, came to account for 35.0% of total lipid. The ester was constituted primarily with linoleic acid (ca. 50%) and oleic acid (ca. 20%), no appreciable change in this proportion being observed during maturation. Also, the proportion was unique in that this did not reflect the fatty acid composition in a mixture of the two materials. It is possible to monitor the maturation of the rice-koji miso by following up the increase with time in fatty acid ethyl ester.     

A mutant with constitutive sexual organ development in<Emphasis Type="Italic"> Marchantia polymorpha</Emphasis> L.

In lower land plants, genes controlling the transition from vegetative growth to sexual reproduction have not yet been identified. In the dioecious liverwort Marchantia polymorpha, the transition to sexual reproduction accompanied by the formation of sexual organs on the gametophytic thallus is initiated under long-day conditions. By particle bombardment-mediated mutagenesis, we generated a mutant of M. polymorpha that constitutively forms sexual organs. This mutant is fully fertile, showing that the mutation does not affect formation of male or female sexual organs per se. Genetic analysis reveals that this phenotype is caused by mutation of a single autosomal locus, suggesting that this mutation defines or controls a gene regulating the transition to sexual reproduction in M. polymorpha.