Dose dependency of prednisolone on the establishment of Echinococcus multilocularis infection in an alternative definitive host, Mongolian gerbil

This study revealed the dose dependency of prednisolone tertiary-butylacetate (PTBA) treatment on the establishment of Echinococcus multilocularis in the small intestine of Mongolian gerbil (Meriones unguiculatus) and that some of the physiological parameters of host were correlated with the doses of PTBA and establishment of the worm. Twenty Mongolian gerbils were divided into 5 groups, according to the doses of PTBA; 0 mg, 0.5 mg, 2 mg, 5 mg and 10 mg per head. All animals were injected intraperitoneally with PTBA every other day from 6 days before to 6 days after infection. Doses of PTBA and the number of worms recovered at 7 days post-infection showed a positive correlation (r = 0.929, P < 0.0001). The increase of total protein (TP) and the decrease of the percentage of lymphocytes in the peripheral leukocytes were dependent on doses of PTBA (TP: r = 0.811, P < 0.0001, percentage of lymphocyte: r = -0.92, P < 0.0001). The TP and the percentage of lymphocyte also correlated with the number of worms recovered (TP: r = 0.617, P = 0.0049; percentage of lymphocyte: r = -0.800, P < 0.0001).     

Differentiation of Toxocara canis and T. cati eggs by light and scanning electron microscopy

In this study, we investigated the morphological identification of Toxocara canis and T. cati eggs on the basis of light and scanning electron microscopic (SEM) observations. T. canis and T. cati eggs used in this study were recovered from the uteri of respective gravid female worms. Measurement of egg size was not helpful in the differentiation of these species, because approximately 90% of eggs measured were of similar size. Using SEM, we were able to differentiate T. canis eggs from T. cati eggs based on their respective characteristic surface structures. Both species have subspherical eggs with markedly pitted surfaces like those of a golf ball, but the surface pitting in T. canis is more coarse than that in T. cati. In this study, however, these differences were not absolute, as 16% of T. canis and 29% of T. cati eggs showed surface pitting that was uncharacteristic of their species. Of the 16% of T. canis eggs that could not be differentiated by surface structure, 3% had pitting resembling T. cati, and the remaining 13% showed intermediate type surface pitting. Similarly, 5% of T. cati eggs resembled T. canis, and 25% of these were of intermediate type. Light microscopic observation yielded results similar to those of SEM, indicating that light microscopy is also a useful tool for the identification of Toxocara eggs.     

Age trends in the genetic parameters of wood density and the relationship with growth rates in hybrid larch (Larix gmelinii var. japonica × L. kaempferi) F1

Age trends in variance components and heritability of overall wood density, earlywood and latewood density, and latewood proportion were investigated in 29-year-old trees of 19 full-sib families of hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F₁. The age–age correlation and optimum selection age for these traits were also estimated and genetic and phenotypic correlations between wood density and radial growth rate were calculated for each growth ring. Intraring wood density data were obtained using X-ray densitometry. The coefficient of additive genetic variance was stable over all ages, whereas the coefficient of environmental variances gradually decreased with increasing age, resulting in increases in heritability estimates with age for overall density. The latewood proportion had the highest heritability estimates at all ages, ranging from 0.44 to 0.66. Overall density and its various components at 28 years of age showed strong genetic correlations with their respective traits at all younger ages. Optimum selection ages for the wood density traits ranged from 8 to 14 years, at which point maximum gain efficiencies per year were obtained. There were negative correlations between wood density and radial growth rate at early ages, although these relationships tended to be weaker with increasing age. These results suggest that selection at a young age is effective for wood density, but particular care must be taken in selecting trees with an improved radial growth rate because rapid growth will result in a low-density wood product, especially in the early growth period.     

Continuum contraction of tension wood fiber induced by repetitive hygrothermal treatment

Wood Science and Technology - Tension wood, when kiln-dried, is likely to deform hugely, which is probably caused by a gelatinous layer of the gelatinous fiber. To elucidate the mechanism behind...     

Detecting endotoxin activity in bovine serum using an automated testing system

The aim of the present study was to compare the ability of the commercially available portable test system (PTS^TM) to detect endotoxin activity in bovine serum, with that of the traditional LAL-kinetic turbidimetric (KT) and chromogenic (KC) assays. Prior to testing, serum samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS^TM was not significantly different from that of the traditional LAL-based assays. The results using PTS^TM correlated with those using KT (r²=0.963, P<0.001) or KC assays (r²=0.982, P<0.001). Based on these findings, the PTS^TM could be applied as a simplified system to assess endotoxin activity in bovine serum.     

Carbon source and trophic position of pelagic fish in coastal waters of south-eastern Izu Peninsula,Japan, identified by stable isotope analysis

ABSTRACT:   It is important to clarify trophic dynamics in marine ecosystems for management of the fishing ground. Organic carbon sources and trophic position of pelagic fishes in the coastal waters of the south-eastern Izu Peninsula, Japan, were examined on the basis of carbon and nitrogen stable isotope distributions. The δ¹³C of the fishes was mostly distributed from −19 to −16‰ for nektonic fishes (13 species of adults and immatures) and planktonic fishes (10 species of larvae and juveniles), close to the δ¹³C values of particulate organic matter and planktonic decapods. These δ¹³C signatures for the inhabitants of the water column were in contrast with the high δ¹³C values (mainly −16 to −13‰) for demersal fishes of Scorpaeniformes and benthic polychaetes collected in the surf zone. These results indicate that nektonic and planktonic fishes depend on phytoplankton for carbon supply. The δ¹⁵N signatures suggest that the trophic position ranged 3.1–4.5 for the nektonic fishes and 2.9–3.7 for the planktonic fishes, premised on trophic level 3 for larval Japanese anchovy Engraulis japonicus . Thus, planktivorous fishes should be mainly assigned to trophic levels 3 and 4 in this area.