Molecular markers for genotyping anastomosis groups and understanding the population biology of Rhizoctonia species

Soil-borne Rhizoctonia fungi cause serious diseases in several plant species. For the classification of these fungi, the number of nuclei in a hyphal cell and the anastomosis reaction are important criteria. Although Rhizoctonia spp. has a wide host range, the causal agents have been reported to be selective for host plant families or species and lead to severe disease. Reports of new diseases, particularly in new host plants, and severe damage in agricultural fields incurred by subdivided or newly found groups of Ceratobasidium and Waitea circinata (a varied teleomorph of Rhizoctonia) have been increasing in recent years. The food production environment is altering because of climate change, introduction of potential new host plants, and heavy use of chemicals that reduce microbial diversity. These changes favor the occurrence of new diseases incurred by undefined anastomosis groups (AGs) or subgroups of Rhizoctonia spp. On the basis of the phylogenetic relationships of AGs and subgroups in Rhizoctonia spp., molecular markers for discriminating the groups of the Rhizoctonia species complex have been developed. The application of genetic markers, in the form of microsatellites or simple sequence repeats (SSR), has become increasingly important in fungal genetics. The analyses of population genetics for Rhizoctonia spp. using SSR markers elucidated the modes of sexual and asexual reproduction, phylogeographical distributions, and global migrations associated with adaptation to agroecosystems.     

Evaluation of combustion properties of wood pellets using a cone calorimeter

In this study, the combustion properties of wood pellets were evaluated using a cone calorimeter, which is usually used to verify the fireproof performance of architectural materials. In contrast to the conventional methods including combustion calorimetry and thermogravimetric analysis, a cone calorimeter can estimate various combustion parameters, e.g., changes of heat release rate (HRR), weight decrease during burning process, ignition time, and flame-out and burn-out time as well as combustion heat, in a single experimental run with no pretreatment for sample size reduction. The following results were obtained by the combustion test of Japanese cedar (Cryptomeria japonica) and larch (Larix kaempferi) wood pellets having various volume densities. Ignition time of wood pellet became slower with increasing volume density of the pellets. However, burn-out time was not clearly correlated to volume density. The heat release values measured by cone calorimeter could be comparable to those from the conventional combustion calorimeters, and flaming heat values of the bark pellets were always lower in comparison with pellets made of xylem, although total heat release was almost the same.     

Thirteen-week Intravenous Toxicity Study of a Novel Humanized Anti-Human Death Receptor 5 Monoclonal Antibody, CS-1008, in Cynomolgus Monkeys

CS-1008, a humanized monoclonal antibody that is agonistic to human death receptor 5, was intravenously administered to cynomolgus monkeys twice a week for 13 weeks at 3 different dose levels (5, 15 and 42 mg/kg) in order to evaluate its potential toxicity. A control group received phosphate buffered saline containing 0.01% polysorbate 80. Each of the 4 groups consisted of 3 male and 3 female cynomolgus monkeys. No animal in any group died during the dosing period. No toxic changes in clinical signs, food consumption, body weight, electrocardiography, ophthalmology, urinalysis, hematology, blood chemistry, gross pathology, organ weights or histopathology were noted in any group during the dosing period. In the toxicokinetic analysis, the values for the maximum concentration of CS-1008 in plasma and the area under the curve generally increased with increasing dose. No clear differences in the toxicokinetic parameters or profiles were observed between the sexes. Development of anti-CS-1008 antibodies was not detected in any sample. The no-observed adverse-effect level (NOAEL) of CS-1008 in cynomolgus monkeys under the conditions of this study was concluded to be 42 mg/kg in both sexes, when administered intravenously twice a week for 13 weeks. This study supports the development of CS-1008 as a therapeutic biopharmaceutical.     

Evaluation of a recombinant measles virus expressing hepatitis C virus envelope proteins by infection of human PBL-NOD/Scid/Jak3null mouse

In this study, we infected NOD/Scid/Jak3null mice engrafted human peripheral blood leukocytes (hu-PBL-NOJ) with measles virus Edmonston B strain (MV-Edm) expressing hepatitis C virus (HCV) envelope proteins (rMV-E1E2) to evaluate the immunogenicity as a vaccine candidate. Although human leukocytes could be isolated from the spleen of mock-infected mice during the 2-weeks experiment, the proportion of engrafted human leukocytes in mice infected with MV (10³–10⁵ pfu) or rMV-E1E2 (10⁴ pfu) was decreased. Viral infection of the splenocytes was confirmed by the development of cytopathic effects (CPEs) in co-cultures of splenocytes and B95a cells and verified using RT-PCR. Finally, human antibodies against MV were more frequently observed than E2-specific antibodies in serum from mice infected with a low dose of virus (MV, 10⁰–10¹ pfu, and rMV-E1E2, 10¹–10² pfu). These results showed the possibility of hu-PBL-NOJ mice for the evaluation of the immunogenicity of viral proteins.     

Simultaneous detection by multiplex PCR of the high-temperature-growing Pythium species: P. aphanidermatum, P. helicoides and P. myriotylum

The objective of this study was to develop a multiplex PCR detection method for the high-temperature-growing pathogens Pythium aphanidermatum, P. helicoides and P. myriotylum. Species-specific primer pairs were designed that targeted the rDNA ITS regions. The multiplex PCR was constructed with a universal primer pair for eukaryotes directed at the 18S rDNA as a positive control, in addition to the three species-specific primer pairs. When the multiplex PCR was applied to naturally infested soils, the expected species were reliably identified, suggesting that the method is suitable for the detection of the three Pythium pathogens in environmental samples.     

Establishment of an in vitro culture model to study milk production and the blood–milk barrier with bovine mammary epithelial cells

This study attempted to establish a culture model to recreate the milk production pathway in bovine mammary epithelial cells (BMECs). BMECs were isolated from Holstein cows (nonlactating, nonpregnant, and parous) and were stored by cryopreservation. To separate the apical and basolateral compartments, BMECs were cultured on a cell culture insert with a collagen gel in the presence of bovine pituitary extract and dexamethasone to induce milk production and tight junction (TJ) formation. The culture model showed the secretion of the major milk components, such as β‐casein, lactose, and triglyceride, and formed less‐permeable TJs in BMECs. Moreover, the TJs were distinctly separated from the apical and basolateral membranes. Glucose transporter‐1, which transports glucose into the cytoplasm through the basolateral membrane, localized in the lateral membrane of BMECs. Toll‐like receptor‐4, which binds to lipopolysaccharide in the alveolar lumen in mastitis, localized in the apical membrane. Beta‐casein was mainly localized near the Golgi apparatus and the apical membrane. Moreover, milk components were almost secreted into the upper chamber of the cell culture insert. These findings indicate that this model has clear cell polarity as well as in vivo and is effective to study of milk production and the blood–milk barrier in lactating BMECs.     

Effect of free-air CO2 enrichment on the storage of carbohydrate fixed at different stages in rice (Oryza sativa L.)

Increasing global atmospheric CO₂ concentrations are expected to influence crop production. To investigate the effect on rice (Oryza sativa L.), plants were grown under ambient CO₂ (AMB) or free-air CO₂-enrichment (FACE) at CO₂ concentrations ranged from 275 to 365 μmol mol⁻¹ above AMB. We supplied ¹³CO₂ to the plants at different growth stages so we could examine the contribution of carbohydrate stored during the vegetative stage or newly fixed carbohydrate produced during the grain-filling stage to ear weight at grain maturity. In plants supplied with ¹³C at the panicle-initiation or pre-heading stages, plants grown under FACE had more starch in the stems at heading, but there was no difference in stem ¹³C content. Furthermore, there were no differences between treatments in whole-plant ¹³C contents at heading and grain maturity. In contrast, plants supplied with ¹³C at the grain-filling stage had more ¹³C in the whole plant and the ears at grain maturity under FACE than under AMB, indicating that the increased amount of photosynthate produced at the grain-filling stage under CO₂ enrichment might be effectively stored in the grains. Furthermore, regardless of when the ¹³C was supplied, plants had more ¹³C in starch in the ears at grain maturity under FACE than under AMB. Therefore, CO₂ enrichment appears to promote partitioning of photosynthate produced during both vegetative and grain-filling stages to the grains.     

Effects of spiracle-blocking insecticides and microbial insecticides on the predator mirid bug, Nesidiocoris tenuis (reuter) (heteroptera: miridae)

Spiracle-blocking insecticides and microbial insecticides are widely used for Integrated Pest Management (IPM) in Japan while Nesidiocoris tenuis is used for the control of thrips and whiteflies in Kochi Prefecture, Japan. However, the effects of the insecticides mentioned above on N. tenuis were unclear. This study investigated the effects of five spiracle-blocking insecticides and two microbial insecticides on the nymphs and adults ofN. tenuis. Propylene glycol fatty acid monoester was slightly harmful to both the nymphs and adults. Hydroxypropyl starch was slightly harmful to the nymphs, while sodium oleate was slightly harmful to the adults. Decanoyloctanoylglycerol and hydrogenated starch hydrolysate were not harmful to either the nymphs or adults. Beauveria bassiana was extremely harmful to the adults and was moderately harmful to the nymphs. Lecanicillium muscarium was slightly harmful to the adults. Therefore, decanoyloctanoylglycerol and hydrogenated starch hydrolysate can be used in combination with N. tenuis to establish an IPM program.     

Assessment of the water quality of two rivers in Hanoi City and its suitability for irrigation water

The To Lich and Kim Nguu Rivers in Hanoi City are the main sources of irrigation water for suburban agricultural land and fish farm. Wastewater from the industrial plants located along these rivers has been discharged, and has degraded the water quality of the rivers. This study describes the chemical properties of water from the rivers, focusing on heavy metal pollution and the suitability of water quality for irrigation water. Water from the rivers was heavily polluted with organic matter and heavy metals such as Pb, Cu, Zn, Cr, Cd and Ni. Dissolved oxygen, chemical oxygen deman, and total suspended solids, and the concentrations of all heavy metals exceeded the Vietnamese standard for surface water quality in all investigated sites. The concentrations of some heavy metals such as Cu, Cd, Cr and Ni were above the internationally recommended WHO maximum level for irrigation water. A wide variation in the heavy metal concentration of water due to metal types is the result of wastewater discharged from different industrial sources.     

柔嫩艾美耳球虫感染对鸡盲肠中一些正常厌氧微生物菌群动态的影响

通过对鸡感染柔嫩艾美耳球虫时盲肠中常见正常厌氧微生物的变化情况进行检测研究发现:鸡在感染球虫后第7、10、14天时盲肠中类杆菌(Bacteriodes)的数量显著减少(P<005),而梭状芽孢杆菌(Clostridium)则显著增多;在球虫感染后的第7、10天时,盲肠中的消化球菌(Peptostreptocuccus)和真杆菌(Eubacterium)呈显著下降(P<005)。上述结果从一个方面阐明了柔嫩艾美耳球虫感染导致对某些其它感染抵抗力下降的机制。