Inhibition activity of essential oils obtained from Japanese trees against <Emphasis Type="Italic">Skeletonema costatum</Emphasis>

The growth inhibition activities of essential oils obtained from Cryptomeria japonica, Chamaecyparis obtusa, and Pinus thunbergii were examined against the bacillariophyceae Skeletonema costatum, also known as red tide plankton. The essential oils were extracted from the heartwood, leaves, and bark of these typical indigenous Japanese conifers. The essential oils from C. japonica bark and P. thunbergii heartwood possessed strong growth inhibition activity. The chemical compositions of these essential oils were analyzed by gas chromatography/flame ionization detection (GC-FID) and gas chromatography/mass spectrometry (GC-MS). α-Terpineol and longifolene were the main components of the essential oil from P. thunbergii heartwood. The C. japonica bark essential oil was mainly composed of α-terpineol, δ-cadinene, isophyllocladene, and ferruginol. Ferruginol and longifolene showed more potent growth inhibition against S. costatum than hinokitiol (β-thujaplicine), which is known to be a strong antifungal compound among wood components. Ferruginol and longifolene were important factors for the growth inhibition activity of the essential oils from C. japonica bark and P. thunbergii heartwood, respectively. These results suggest the possibility of using C. japonica bark and P. thunbergii heartwood for the control of red tide plankton.     

Oceanographic factors affecting interannual recruitment variability of Pacific saury (Cololabis saira) in the central and western North Pacific

Pacific saury (Cololabis saira) has a short life span of 2 years and tends to exhibit marked population fluctuations. To examine the importance of sea surface temperature (SST) and mixed layer depth (MLD) as oceanographic factors for interannual variability of saury recruitment in early life history, we analyzed the relationship between abundance index (survey CPUE (catch per unit of effort)) of age‐1 fish and the oceanographic factors in the spawning and nursery grounds of the previous year when they were born, for the period of 1979–2006, in the central and western North Pacific. Applying the mixture of two linear regression models, the variability in the survey CPUE was positively correlated with previous year's winter SST in the Kuroshio Recirculation region (KR) throughout the survey period except 1994–2002. In contrast, the survey CPUE was positively correlated with the previous year's spring MLD (a proxy of spring chlorophyll a (Chl‐a) concentration) in the Kuroshio‐Oyashio Transition and Kuroshio Extension (TKE) during 1994–2002. This period is characterized by unusually deep spring MLD during 1994–1997 and anomalous climate conditions during 1998–2002. We suggest that saury recruitment variability was generally driven by the winter SST in the KR (winter spawning/nursery ground), or by the spring Chl‐a concentration (a proxy of prey for saury larvae) in the TKE (spring spawning/nursery ground). These oceanographic factors could be potentially useful to predict abundance trends of age‐1 saury in the future if the conditions leading to the switch between SST and MLD as the key input variable are elucidated further.     

Concentration of cephalothin in body fluids and tissue samples of Thoroughbred horses

Cephalothin (CET) concentrations in body fluids (plasma, synovial fluid, pleural fluid, peritoneal fluid, and aqueous humor) and tissue samples (bone, lung, jejunum, hoof, and subcutaneous tissue) were investigated to consider the treatment of infectious diseases in horses. CET 22 mg/kg body weight was intravenously administered to 12 horses. Samples were collected from four different horses at 1, 3, and 5 hr after administration. The CET concentration in body fluids other than aqueous humor was maintained above the MIC₉₀ values of Streptococcus zooepidemicus and Staphylococcus aureus until 5 hr, but it was not maintained above that of S. aureus in bone. CET (22 mg/kg twice a day) is effective for septic arthritis, pleuritis, and peritonitis caused by gram-positive bacteria but ineffective for osteomyelitis.     

Occurrence of blood disease of banana in Sumatra,Indonesia

Since 1991, the sudden death of cultivated banana plants has been widely observed in the southern region of Sumatra Island, Indonesia. Wilting from loss of petiole and midrib turgidity, yellowing, and necrosis of leaves was followed by death of the whole plant. Reddish brown bacterial ooze exuded from the cut surface of infected pseudostems and fruits. The colony appearance of the isolated bacterium was similar to that of Ralstonia solanacearum. The bacterium was pathogenic to banana plants but not to tomato. Its bacteriological properties agreed with those of blood disease bacterium (BDB) of banana described previously. The 16S rDNA sequence of strain Banana E had conserved bases characteristic of BDB. Based on these results, the causal agent was identified as BDB, which is a close relative of Ralstonia. The isolates have resistance against antibiotics, such as chloramphenicol and tetracycline.The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession number AB095535     

Construction of chicken-mouse chimeric antibody and immunogenicity in mice

Chicken monoclonal antibodies are potentially useful for diagnostic research and have clinical applications, as chicken show higher potential for antibody production with mammalian-conserved biological molecules. However, the applications of chicken antibodies are limited because of their immunogenicity in mammals. To overcome this problem, we have constructed a chicken-mouse chimeric antibody containing the chicken variable region and the mouse constant region. This chimeric antibody retained similar binding affinities as the parental chicken antibody. The chimeric antibody was also producible as an ascitic antibody in BALB/c mice. Furthermore, when the chimeric antibody was administered to mice, it did not provoke the mouse anti-chicken antibody response. These results indicate that the chimeric antibody is suitable for application to preclinical mouse studies.     

Stand structure and plant species occurrence in forest edge habitat along different aged roads on Okinawa Island, southwestern Japan

We compared stand structure and plant species occurrence on the shoulders of 3-, 10- and 20-year-old roads in a subtropical evergreen broad-leaved forest to document temporal changes in edge effects of forest roads. We recorded 154 vascular species in the study plots, including 3 non-native species. We used generalized linear mixed models to analyze changes in forest structure and plant species composition in relationship to the distance from forest roads. The spatial patterns in stand structure at different distances from roads differed with road age. The large canopy openness on the edge of 3-year-old roads decreased with time after the construction. A progressive decrease in tree height on roadsides was observed after the road construction, suggesting tall trees could not withstand the dry and windy roadside environment. The edge effect on the canopy tended to be larger at higher elevation sites. The spatio-temporal pattern of species occurrence based on distance from roads differed by species. Typical pioneer species such as Schima wallichii and Eurya japonica increased along the edge, while less aggressive pioneer species and understory species decreased. As time passed after the road construction, some climax and understory species decreased at the forest edge, while other climax and understory species increased. The modeling methods proposed in this study could be applied to different roadside and edge study sites.     

Physicochemical and functional properties of buckwheat protein product

This study was conducted to compare the physicochemical and functional properties of buckwheat protein product (BWP), soy protein isolate (SPI), and casein. BWP was prepared from buckwheat flour by the method including alkaline extraction and isoelectric precipitation. The amino acid composition of BWP was very similar to that of buckwheat flour. The protein solubility (PS) of BWP was much greater than that of SPI at all pH levels (pH 2-10) but lower than that of casein at pH 7-10. The isoelectric point of BWP was around pH 4. The higher aromatic hydrophobicities (ARH) of BWP, SPI, and casein were obtained at lower pH levels (pH 2-3). The emulsifying stability (ES) of BWP was lower than those of SPI and casein at high pH levels (pH 7-10). At all pH levels, BWP formed a thin emulsion. Regression analysis showed that the ARH of BWP was significantly associated with the ES. Although the water holding capacity of BWP was quite lower than that of SPI, its fat absorption capacity was slightly higher than those of SPI and casein. These results indicated that the physicochemical properties of BWP were different from those of SPI or casein. Thus, BWP is a potential source of functional protein for possible food application.