Hemorrhagic necrotizing splenitis in a slaughter pig infected with Arcanobacterium species

A 6-month-old barrow presented with lethargy, inappetence and dysstasia. At necropsy, multiple coalescing hemorrhagic foci were detected in the margins of the spleen. Gram-positive bacilli were isolated from the spleen, kidney, muscle and liver. Comparative 16S rDNA gene sequencing analysis of the isolates (TO16177) revealed that they would be the same species of unpublished Arcanobacterium species strain HJ57-14E (accession no. gi 18873551) (99.7% similarity based on a comparison of 675 bp). Histologic examination of the splenic tissue sections revealed extensive necrosis and inflammation, and gram-positive bacilli were discernible. Multifocal necrosis was also detected in the liver. Immunohistochemically, the isolates were cross-reacted with polyclonal antibodies against Arcanobacterium pyogenes and Actinomyces naeslundii, and the reaction was strong for the latter. Similar reactions were found in the suppurative lesions of the tonsil, and occasionally in the spleen and lymph nodes. The present results indicate that the unpublished Arcanobacterium species induced multiple organ failure accompanied by acute hemorrhagic necrotizing splenitis in this growing-finishing pig.     

Lesion-based analysis of leaf blast suppression in mixture of rice cultivar and a resistant near-isogenic line

Leaf blast suppression in multilines was evaluated based on the number of susceptible lesions observed in a pure stand of susceptible rice cultivar Sasanishiki, and in 1 : 1 and 1 : 3 mixtures of Sasanishiki and a resistant near-isogenic line, Sasanishiki BL4 or BL7, from 1998 to 2001. The number of lesions first observed in fields in the 1 : 1 and 1 : 3 mixtures were close to theoretical numbers calculated using the number of lesions observed in the pure stands and the ratios of the susceptible Sasanishiki in the mixtures. The ratio of the number of lesions in the 1 : 1 and 1 : 3 mixtures to the number in the pure stand was 0.29 and 0.09, respectively. The relationship between these ratios and the ratios of susceptible Sasanishiki in mixtures was defined in an equation to estimate the degree of leaf blast suppression. Validation studies for the ratios of the number of lesions in the 1 : 1 and 1 : 3 mixtures to the number in the pure stand were conducted in two different locations and showed that the ratios are almost acceptable. The calculated autoinfection to alloinfection ratio was 1.3 and 1.4 in the 1 : 1 and 1 : 3 mixtures, respectively, suggesting that the calculated ratio will affect the degree of leaf blast suppression. Thus, predictors were obtained to estimate leaf blast suppression for effective blast control in multilines.     

Phenology and photosynthetic traits of short shoots and long shoots in Betula grossa

Leaf phenology, growth irradiance (i.e., photosynthetic photon flux (PPF) at the leaf surface) and photosynthetic capacity (A(area); measured at a PPF of 1000 micro mol m(-2) s(-1) and expressed on a leaf area basis) were investigated in early leaves (ELs) and late leaves (LLs) of Betula grossa Siebold & Zucc. trees. Early leaves first appeared on morphologically distinct long shoots and short shoots. The appearance of ELs, which was restricted to the bud break period, was followed by the successive appearance of LLs on long shoots only. Late leaves appeared successively until the middle of the growing season. Late leaves started to abscise around the middle of the growing season, whereas ELs on both long and short shoots did not abscise until near the end of the growing season. Solar irradiance was higher at the surface of LLs of late appearance than at the surface of either LLs of early appearance or ELs. Solar irradiance at the surface of ELs decreased after LLs appeared. In both long and short shoots, A(area) of ELs increased and then remained stable for 65-80 days before starting to decrease. Although A(area) was higher in LLs than in ELs for a short time in August, it started to decrease earlier in LLs than in ELs. Area-based nitrogen concentration (N(area)) was higher in LLs than in ELs after August. Although N(area) decreased slowly in ELs after August, it did not decrease in LLs. In both ELs and LLs, A(area)/N(area) decreased with time. The crown was thus characterized by a rapidly growing surface with young LLs having high A(area) and by shaded inner parts with ELs having stable low A(area).     

Identification of a novel cytotoxic protein, Cry45Aa, from Bacillus thuringiensis A1470 and its selective cytotoxic activity against various mammalian cell lines

Parasporal inclusion proteins produced by Bacillus thuringiensis strain A1470 exhibit strong cytotoxicity against human leukemic T cells when activated by protease treatment. One of the cytotoxic proteins was separated by anion exchange chromatography and gel filtration chromatography and designated Cry45Aa. Its gene was then expressed in recombinant Escherichia coli, in which the Cry45Aa precursor was accumulated in an inclusion body. It was solubilized in sodium carbonate buffer and processed with proteinase K, and cytotoxic activities of the protein against various mammalian cell lines were evaluated using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide assay. The protein exhibited high cytotoxic activity against CACO-2, Sawano, MOLT-4, TCS, and HL60 cells and moderate activity against U-937 DE-4, PC12, and HepG2 cells. On the other hand, the EC50 values against Jurkat, K562, HeLa, A549, Vero, COS-7, NIH3T3, CHO, and four normal tissue cells (human primary hepatocyte cells, UtSMC, MRC-5, and normal T cells) were >2 microg/mL.     

Yield—Density diagram for natural deciduous broadleaved forest stands

A yield—density diagram for natural deciduous broad-leaved forests in Hokkaido was devised. It consists of Y—N curves, equivalent diameter curves, equivalent mean diameter curves, a B-point curve and a full density curve. The Y—N curve is derived from the relation between cumulative summation (Y) of individual tree volume from the maximum sized tree to one of a certain given volume, and number (N) of these trees, and is expressed by the reciprocal equation of two parameters, A and B. The equivalent diameter curve expresses the number of trees whose diameters are larger than a certain size. The equivalent mean diameter curves express the number and volume of trees of selected mean diameters. The B-point curve is a hypothetical trajectory of the B-point of the C—D curved ruler (C—D rule) which is fitted to each Y—N relation, throughout the course of stand development. The full density curve indicates the upper limit of the number and volume of the standing trees. Utilizing this diagram, we can comprehend numbers, volumes and tree diameters in a stand and among stands.A method is devised of predicting the number and volume of each diameter class of a stand several years after thinning. Thinned trees are assumed to be selected equally from each diameter class so that the Y—N curves are fitted equally to the Y and N data before and after thinning. Volume growth of individual trees is assumed to be proportional to their volumes after thinning. The current volume growth of the stand after crown closure is assumed to be constant irrespective of the stand age. Tree mortality after thinning is assumed to be negligible. With these assumptions, a trajectory of the Y—N curve through thinning is determined, and a yield after n years from thinning is predicted. Comparing the Y—N curve of a thinned stand with that of an unthinned stand after n years from thinning, we can comprehend the thinning effect.     

Efficacy of ivermectin against live mites and eggs of Sarcoptes scabiei in pigs

Sows infested with Sarcoptes scabiei var. suis (ssvs) were treated with 75, 150 and 300 micrograms/kg of ivermectin by a single subcutaneous injection at the neck region. Compared to the numbers of mites and eggs just before injection, those on post treatment weeks (PTW) 1, 2 and 4 showed significant decreases. Especially at 300 micrograms/kg, the counts showed almost all mites and eggs were eradicated on PTW 1, manifesting ivermectin to possess potential effect on ssve without apparent abnormal side effect. Potential mitocide effect of ivermectin on ssvs was revealed.     

Risk evaluation and tree improvement as components of intensive forest management in Japan

Forestry practice differs from agricultural crops practice owing to the huge size of trees, their longevity and the variety of uncontrollable conditions under which they grow. Even with intensive forest management, the actual effects of investment of labour and materials in the forest seem to be fairly small because of the size of the forest and the long harvest rotation. Since we expect to produce both a higher quantity and a higher quality of timber with intensive forestry, it is very important to have adequate counter-measures to the fatal or destructive factors which affect forest establishment and growth. In Japan, in the field of forest tree breeding, we are making maps as information sources for decision making, in which iso-lines show the degrees of damage due to fatal factors such as pests and diseases. If there is more than one fatal factor overlapping in an area, it might be difficult to grow forests for commercial purposes. We have to decide how to use the forest land in these areas, or how to take counter-measures such as tending, chemical control, genetic improvement or even a change in the tree species. As forestry has a long harvest rotation, it is necessary to have ‘a quality control system’ in management, in which a follow-up assessment of planting materials, tending techniques in combination with site conditions, and fatal factors will be made. In this situation, forest tree improvement (breeding) seems to be of prime importance in intensive forest management in the future.     

Loop-mediated isothermal amplification for the rapid, sensitive, and specific detection of the O9 group of Salmonella in chickens

In the present study, the loop-mediated isothermal amplification (LAMP) assay was developed to amplify the fragments of the O9 Salmonella-specific insertion element and evaluated in the laboratory for its potential use in a field situation, such as poultry farms. Among the bacteria tested, a positive reaction was observed only for 128 strains of 6 serovars of the O9 group Salmonella, such as Enteritidis (SE) and Pullorum. The detection limit of the LAMP assay was 10(3)CFU/ml, which was more sensitive than that of the polymerase chain reaction (PCR) assay with the same target gene (10(6)CFU/ml). The final results were obtained within 30 min for the LAMP assay, while the PCR assay needed a total of 120 min. When the LAMP assay was applied to the enrichment broth mixed with cecal dropping samples either spiked with SE in vitro or excreted by SE-inoculated hens, the results were comparable to those of the conventional plating method including 2 separate enrichments. In conclusion, the LAMP assay developed in the present study is an effective method for the specific detection of the O9 group Salmonella serovars, including SE.     

Micropropagation of Bolaina blanca (Guazuma crinita Mart.), a fast-growing tree in the Amazon region

Rapid clonal propagation of Bolaina blanca (Guazuma crinita Mart.) was established by the subculturing of the shoot-tips from aseptically germinated seedlings on woody plant medium (WPM) supplemented with trans-zeatin [trans-6-(4-Hydroxy-3-methylbut-2-enylamino)purine] (ZEA). After 45 days of culture, a seven-fold multiplication rate was achieved on WPM containing 10 μM of ZEA. Obtained shoots were simultaneously elongated and rooted on WPM containing 1 μM of kinetin [6-furfurylaminopurine] (KIN). After 60 days of culturing the growth of shoots was evident, and high rooting percentages were obtained. The plantlets were transferred into pots with vermiculite and acclimatized successfully in plastic boxes with transparent cover inside the growth cabinet.     

Pericardial mesothelioma in a neonatal calf

We encountered an extremely rare tumor, a pericardial mesothelioma, in a neonatal calf. The patient calf showed severe abdominal distention, and died immediately after birth. The thoracic cavity was contained a huge heart with a large amount of pericardial fluid. A number of granular and cobblestone-like nodules were dispersed over the epicardium and pericardium. The nodules consisted of papillary proliferations of neoplastic cells, and the neoplasm occasionally showed mesenchymal proliferations. Immunohistochemistry revealed that they had the characteristics of mesothelial cells (cytokeratin-and vimentin-positive), and the neoplasm was diagnosed as mesothelioma.