Determination of plasma vitamin C concentration in fattening cattle

Plasma vitamin C (ascorbic acid + dehydroascorbic acid) concentration is a good index of the nutritional status of vitamin C. However, the methodologies for storage and analyses have not been investigated in bovine plasma. The validity of an analytical method for bovine plasma using high performance liquid chromatography (HPLC) with a spectrophotometric detector was examined. Exogenous dehydroascorbic acid was almost completely converted to ascorbic acid during the preparation for analysis with a reducing reagent, dithioerythritol. The analytical recoveries of ascorbic acid were high. Ascorbic acid was not detected after treatment with ascorbic acid oxidase. Thus, the specificity of this method is considered to be high. Although vitamin C was stable in plasma treated by dithioerythritol at ?20°C for 6 days, vitamin C in untreated plasma significantly decreased during 3‐day storage at ?20°C. These results indicate that the HPLC method is suitable for the determination of plasma vitamin C in cattle and that the storage conditions are important for determination of plasma vitamin C. Plasma vitamin C concentration ranged between 1.49 mg/L and 3.33 mg/L in fattening cattle. This result suggests that fattening cattle show large individual variation in plasma vitamin C concentration.     

First report of powdery mildew on zinnia, blue torenia, dahurian patrinia and scoparia caused by genus Euoidium in Japan

Zinnia, blue torenia, dahurian patrinia, and scoparia were found to be affected by powdery mildews from 2006 to 2008 in Tokyo. Abundant white, powdery colonies were observed to grow on the stems and leaves of each plant species resulting in chlorosis and eventual dieback of infected leaves and stems. Based on the morphological characteristics of the strain from each plant species, the causal agents were determined to belong to the genus Euoidium and pathogenicity to each original host was confirmed through inoculation experiments. This is the first report of Euoidium infection on these four plant species in Japan.     

Chemical control of plant diseases

As the world population increases, we also need to increase food production. Chemical control has been critical in preventing losses due to plant diseases, especially with the development of numerous specific-action fungicides since the 1960s. In Japan, a host-defense inducer has been used to control rice blast since the 1970s without any problems with resistance development in the pathogen. Leaf blast has been controlled using a labor-saving method such as the one-shot application of a granular mixture of fungicide and insecticide to nursery boxes, which became mainstream in the 2000s. However, the need for many choices of fungicides that have several modes of action was demonstrated by the development of resistance to cytalone dehydratase inhibitors. In Europe, many pathogens have threatened cereals since the great increase in cereal production in 1970s, creating a large market for broad-spectrum fungicides. In Brazil, Phakopsora pachyrhizi was distributed to large soybean acreages during 2000s, and the outbreak of soybean rust resulted in a large increase in fungicide use. While the importance of chemical control is recognized, fungicide resistance is an avoidable problem; published guidelines on countermeasure and manuals on testing sensitivity to fungicides are available. Since chemical regulations have become stricter, new fungicides are less likely to be developed. Our task is to maintain the effectiveness and diversity of the present modes of action for fungicides and implement countermeasures against the development of fungicide resistance.     

The effects of short-term nutritional stimulus before and after the luteolysis on metabolic status, reproductive hormones and ovarian activity in goats

The effect of short-term nutritional supplementation on hormonal and ovarian dynamics was studied in goats. Cycling Shiba goats were divided randomly into maintenance (group M, n=4) and high-energy (group H, n=4) groups. After the detection of the ovulation (Day 0, 1(st) ovulation), group H received a high-energy diet providing 2.5 times of the maintenance energy requirement for 7 days from Day 7 to Day 13 and were administered 2 mg of prostaglandin F(2alpha) (PGF(2alpha)) on Day 10 to induce luteal regression followed by the follicular phase. Follicular and luteal dynamics were monitored using ultrasonography daily or every other day, and blood samples were collected daily from Day 0 to the third ovulation (3(rd) ovulation) following the second ovulation (2(nd) ovulation) induced by PGF(2alpha) administration. Blood samples were also collected at 10-min intervals for 6 h on Day 9 and Day 11 for analysis of pulsatile LH secretion. The mean concentrations of glucose and insulin were significantly (P<0.05) higher in group H than in group M on Days 8, 9, 12, 13 and Days 8, 9 and 10, respectively. For both the 2(nd) and 3(rd) ovulations, no significant difference was detected in ovulation rate between groups M and H. On the other hand, the interpeak interval for wave-like patterns of FSH in group H was significantly (P<0.05) shorter than in group M during the period between the 1(st) and 2(nd) ovulations (4.3 +/- 0.3 vs. 6.5 +/- 1.5 days). The mean LH pulse frequency in group H was significantly (P<0.05) greater than in group M on Day 11 (4.5 +/- 0.6 vs. 3.3 +/- 0.5 pulses/6 h). The present study clearly demonstrated that short-term (7 days) nutritional supplementation promoted pulsatile LH and wave-like FSH secretions in cycling goats. However, no significant increase in ovarian performance was found under such endocrine and metabolic conditions.     

Purification and structure determination of glucosides of capsaicin and dihydrocapsaicin from various Capsicum fruits

Two new glucosides, capsaicin-beta-D-glucopyranoside (1) and dihydrocapsaicin-beta-D-glucopyranoside (2), were discovered in the fruit of the Capsicum annuum cultivar 'High Heat'. They were sequentially purified by acetone extraction, n-hexane extraction, and acetonitrile extraction, followed by medium-pressure liquid chromatography and high-performance liquid chromatography performed on an octadecylsilane column. Their chemical structures were elucidated by proton nuclear magnetic resonance, carbon nuclear magnetic resonance, and hydrolysis with alpha- and beta-glucosidases. The glucosides were also detected in various pungent cultivars of C. annuum, Capsicum frutescens, and Capsicum chinense by liquid chromatography-mass spectrometry. However, they were not detected in nonpungent cultivars of C. annuum. Furthermore, a positive correlation was observed between the quantity of the capsaicinoids, capsaicin, and dihydrocapsaicin and their glucosides.     

Proportional limit of wood obtained from a load-time diagram during an impact bending test

We transferred the linear part of a load-deflection diagram from an impact bending test of wood into a load-time diagram. In addition, we proposed a method to obtain the proportional limit from the load-time diagram. Japanese cedar (Cryptomeria japonica D. Don), hondo spruce (Picea yezoensis Carr. var.hondoensis Rehd.), hiba arbor-vitae (Thujopsis dolabrata Sieb. et Zucc.), Japanese red pine (Pinus densiflora Sieb. et Zucc.), paulownia (Paulownia tomentosa Steud.), Manchurian ash (Fraxinus mandshurica Rupr.), and Japanese evergreen oak (Quercus acuta Thunb.) were used in this study. The dimensions of each specimen were 115mm (L) * 7mm (R) * 7mm (T). The results were as follows: (1) The linear region of the load-deflection diagram in the impact bending test could be transferred with sufficient accuracy to a load-time diagram using a sine function. (2) Approximating the load-time diagram by a linear equation was useful for obtaining the proportional limit.     

Molecular and immunochemical characteristics of monoclonal and recombinant antibodies selective for the triazine herbicide simetryn and application to environmental analysis

A monoclonal antibody (mab) selective for the thiomethyl-s-triazine herbicide simetryn was obtained and characterized in enzyme-linked immunosorbent assay (ELISA). An IC(50) value for simetryn was 8.5 ng/mL, and the detection range extended from 1.1 to 70 ng/mL in ELISA. The cDNAs encoding variable heavy chain (VH) and variable light chain (VL) of the mab were cloned to produce various recombinant antibodies. Single-chain variable fragment (scFv) antibodies derived from the mab were characterized in ELISA and showed similar reactivities and specificities to the parent mab. A urea denaturation test revealed that the scFv antibodies bound to simetryn were more stable than those in the absence of antigen. A sandwich ELISA based on VH and VL fragments of the mab was successfully developed and showed similar sensitivity to those based on the mab and scFv antibodies in ELISA. In the recovery experiments using spiked environmental samples, the results obtained in ELISA based on the mab were favorably correlated with those by HPLC.     

Development of taxon-specific sequences of common wheat for the detection of genetically modified wheat

Qualitative and quantitative Polymerase Chain Reaction (PCR) systems aimed at the specific detection and quantification of common wheat DNA are described. Many countries have issued regulations to label foods that include genetically modified organisms (GMOs). PCR technology is widely recognized as a reliable and useful technique for the qualitative and quantitative detection of GMOs. Detection methods are needed to amplify a target GM gene, and the amplified results should be compared with those of the corresponding taxon-specific reference gene to obtain reliable results. This paper describes the development of a specific DNA sequence in the waxy-D1 gene for common wheat (Triticum aestivum L.) and the design of a specific primer pair and TaqMan probe on the waxy-D1 gene for PCR analysis. The primers amplified a product (Wx012) of 102 bp. It is indicated that the Wx012 DNA sequence is specific to common wheat, showing homogeneity in qualitative PCR results and very similar quantification accuracy along 19 distantly related common wheat varieties. In Southern blot and real-time PCR analyses, this sequence showed either a single or a low number of copy genes. In addition, by qualitative and quantitative PCR using wx012 primers and a wx012-T probe, the limits of detection of the common wheat genome were found to be about 15 copies, and the reproducibility was reliable. In consequence, the PCR system using wx012 primers and wx012-T probe is considered to be suitable for use as a common wheat-specific taxon-specific reference gene in DNA analyses, including GMO tests.