Time course of the incidence/multiplicity and histopathological features of murine colonic dysplasia,adenoma and adenocarcinoma induced by benzo[a]pyrene and dextran sulfate sodium

Benzo[a]pyrene (BP) is mutagenic but noncarcinogenic in the murine colon. Recently, we reported rapid induction of colonic tumors by treatment of CD2F₁ mice with BP (125 mg/kg for 5 days) followed by a colitis inducer, dextran sulfate sodium (DSS) (4% in drinking water for 1 or 2 weeks). However, there are no reports on detailed time course and histopathological features of colonic proliferative lesions in this model. Here, we show the detailed time course of colonic dysplasia, adenoma and adenocarcinoma induced by treatment with BP, DSS, and a combination of the two (BP/DSS). In the colon of mice exposed to BP/DSS, 14.6 dysplastic foci per mouse were present one week after DSS treatment (week 4). The number of dysplastic foci decreased with time to 3.1 at week 9 and thereafter remained almost constant. At week 4, 1.5 adenocarcinomas were also observed, with a marked increase in numbers with time, reaching 29.3 at week 14. In contrast, the number of dysplastic foci induced by DSS alone showed a time course similar to that following BP/DSS treatment; however, only a few tumors appeared. Neither dysplastic foci nor neoplastic lesions were induced by BP only. In mice exposed to BP/DSS, β-catenin was demonstrated immunohistochemically in the nucleus and/or cytoplasm of the tumor cells, and this translocation from the cell membrane was evident in subsets of dysplastic foci. In dysplastic foci induced by DSS alone, β-catenin was absent in the nucleus/cytoplasm. These finding suggest that aberrant β-catenin accumulation in dysplastic foci is associated with tumor progression in this BP/DSS model.     

Mixing‐Recording Method for the Practical Determination of Physical Properties of Soy Protein Isolate

The mixing properties of soy protein isolate (SPI) were investigated. The electric current of a kitchen food processor was monitored during the mixing of SPIs to produce dough, and an identical mixing curve was obtained for each SPI. The obtained peak time and peak height of the electric current curve were correlated to the physical properties (solubility and gel strength) of each SPI. The peak time negatively correlated with solubility, and the peak height positively correlated with gel strength. Optical microscopic observations showed that the dough microstructure appeared to be related to the peak time. Moreover, some conditions such as the SPI storage conditions and the ionic strength of the mixing buffer affected the mixing properties. This mixing‐recording method is proposed as a practical tool that could simplify the evaluation of SPI characteristics.     

Goat milk acceptance and promotion methods in Japan: The questionnaire survey to middle class households

A consumer questionnaire conducted with the purpose of ascertaining the acceptability of goat milk and related products in Japan was carried out on 345 guarantees of Nippon Veterinary and Life Science University in December 2006. 275 effective responses (79%) representing middle class urban households were returned. The results revealed that (1) 30% of respondents have experienced drinking goat milk and only 10% are aware of the current retail situation of goat milk and related products; (2) over 70% of goat milk drinkers raised goats by hand at some point in their past and their first experience drinking goat milk was in infancy; (3) those with experience in drinking goat milk expressed a vague evaluation and minimal understanding of drinking goat milk; (4) respondents who were inexperienced goat milk drinkers expressed a strong desire to taste and a weak desire to purchase goat milk; (5) respondents expressed low recognition regarding retailed goat milk products, but those who had already purchased goat milk products expressed a high evaluation and strong desire to purchase these products again; and (6) recognition of goat milk characteristics is low, but those with high recognition also rate goat milk highly. Goats are perceived as being 'mild and familiar.' It is necessary for those who manage goat husbandry to present goat milk and related product tasting opportunities to consumers. The key point is to make the functional differences between cow and goat milk clear and present the advantages of goat milk at the fore of this promotion. Goat milk should not be promoted merely as a drink that is similar to cow milk, but must be positioned as a functional drink or health food in order to expand the Japanese goat milk market.     

Preface

Water, Air, &; Soil Pollution -     

Relationship between zooplankton abundance and the early marine life history of juvenile chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis> in eastern Hokkaido,Japan

Interannual variations in abundance, timing of outmigration from rivers, growth rate and condition of juvenile chum salmon (Oncorhynchus keta) were studied in the Nemuro Strait (eastern Hokkaido, Japan) during 1999–2002 to establish a possible relationship to zooplankton abundance. The otolith microstructure of juveniles was examined each year in late June to determine their time and size at sea entry (i.e., outmigration), and to estimate the early marine growth rates. Salmon outmigration peaked in mid- or late May, which coincided, in three of the four study years, with the peak release of juveniles into rivers within the study area. Abundance, growth rate and condition of fish were higher in 2001, when—compared to other years—smaller fish experienced higher growth rates, coinciding with greater zooplankton abundance for that year. Our results suggest that high zooplankton abundance positively influenced juvenile chum salmon growth and the condition of the fish during their early marine life despite their small size at sea entry.     

Guanine-cytosine contents of the host and symbiont cDNA in a symbiotic coral

ABSTRACT:   Hermatypic (reef-building) corals harbor dinoflagellate endo-symbionts Symbiodinium spp. In studying gene expression in such symbiotic corals, problems arise regarding how to distinguish the coral and symbiont mRNA, and how to estimate their fractions in the mRNA population of the holobiont (symbiotic complex of the coral and Symbiodinium cells). In this study, these issues were addressed using juveniles of hermatypic coral Acropora tenuis in symbiosis with Symbiodinium cells of strain PL-TS-1. First, the guanine-cytosine (GC) contents were determined in expressed sequence tags (EST) from PL-TS-1 cells cultured in vitro and symbiont-free larvae of A. tenuis , and their average GC contents were found to be significantly different. The average GC content of the EST from the holobiont was much closer to that of A. tenuis larvae, suggesting that the majority (>90%) of mRNA isolated from the holobiont originated in the host. In protein-coding sequences, little overlap was observed between the GC-content distributions of PL-TS-1 cells and A. tenuis larvae. All of the coding sequences ( n  = 59) found in the A. tenuis EST had GC contents below 0.5, whereas the GC content exceeded 0.5 in the majority (43/44) of coding sequences from the nuclear genome of PL-TS-1 cells.     

The estimation of duration of maternally-derived antibodies against Akabane,Aino, and Chuzan virus in calves by the receiver operating characteristic analysis

The duration of maternally-derived antibodies against three arboviruses was investigated in calves, using the results of arbovirus serosurveillance performed in Kagoshima Prefecture during 2002–2016. The duration of maternally-derived antibodies against Akabane virus (AKAV), Aino virus (AINOV), and Chuzan virus (CHUV) was estimated to be 178 (sensitivity: 0.769, specificity: 0.730), 156 (sensitivity: 0.806, specificity: 0.791), and 156 days of age (sensitivity: 0.845, specificity: 0.814), by receiver operating characteristic analysis. The duration of maternally-derived antibodies against AKAV, AINOV, and CHUV differed 7–14, 22–28, and 20–31 days in the same calf types between the regions far from each other although it was similar between the adjacent regions. The dairy calves showed 6–29 days longer duration than the beef calves rearing in a similar region.