Interaction between optical isomerism and plant pharmacological action,change of modes of action and chirality of 1-(α-methylbenzyl)-3-p-tolylurea

The optical isomers, (R)-1(α-methylbenzyl)-3-p-tolylurea ((R)-MBU) and (S)-1-(α-methylbenzyl)-3-p-tolylurea ((S)MBU), which are analogues of daimuron [1-(α,α-dimethylbenzyl)-3-p-tolylurea], a herbicide for Cyperaceae weeds and a safener for paddy rice, exhibited different biological responses. These two physiological properties of daimuron were observed separately in (R)-MBU and (S)-MBU. Only (R)-MBU had herbicidal activity against Cyperaceae weeds, while the (S)-isomer was a more effective safener against bensulfuron-methyl (BSM) injury of rice seedlings than was (R)-MBU. (S)-MBU promoted root growth of rice seedlings, but the (R)-enantiomer inhibited root growth. (S)-MBU was a more potent inhibitor than (R)-MBU on PS II reaction of spinach broken chloroplasts. Furthermore, (S)-MBU and (R)-MBU showed cross intergenus selective phytotoxicity among the Gramineae plants, Oryza sativa L. (rice, cv. Tsukinohikari, japonica), Triticum aestivum L. (wheat, cv. Norin No. 61) and Echinochloa crusgalli var. frumentacea Wight, on root growth inhibition in the dark.     

Cytological events in tomato leaves inoculated with conidia of <Emphasis Type="Italic">Blumeria graminis</Emphasis> f. sp. <Emphasis Type="Italic">hordei</Emphasis> and <Emphasis Type="Italic">Oidium neolycopersici</Emphasis> KTP-01

Leaves of tomato and barley were inoculated with conidia of Blumeria graminis f. sp. hordei race 1 (R1) or Oidium neolycopersici (KTP-01) to observe cytological responses in search of resistance to powdery mildew. Both conidia formed appressoria at similar rates on tomato or barley leaves, indicating that no resistance was expressed during the prepenetration stage of these fungi. On R1-inoculated tomato leaves, appressoria penetrated the papillae, but subsequent haustorium formation was inhibited by hypersensitive necrosis in the invaded epidermal cells. On the other hand, KTP-01 (pathogenic to tomato leaves) successfully developed functional haustoria in epidermal cells to elongate secondary hyphae, although the hyphal elongation from some conidia was later suppressed by delayed hypersensitive necrosis in some haustorium-harboring epidermal cells. Thus, the present study indicated that the resistance of tomato to powdery mildew fungi was associated with a hypersensitive response in invaded epidermal cells but not the prevention of fungal penetration through host papilla.     

Consecutive monitoring for conidiogenesis by Oidium neolycopersici on tomato leaves with a high-fidelity digital microscope

Conidiogenesis by Oidium neolycopersici KTP-01 on tomato leaves was vitally monitored with a high-fidelity digital microscope. Conidiophores were initially formed 3 days after inoculation and then elongated to a maximum length within at least 12h. The apical part was split into two cells after two successive septations, accompanied by apical expansion. These cells subsequently developed into primary and secondary conidia. An additional septation at the stem portion of the conidiophores produced a generative and a foot cell. Subsequent conidiation occurred during repeated cycles of splitting of the generative cell, maturation of the apical cell into a conidium, and abstriction of the conidium. To our knowledge, this report is the first on the developmental process of conidiogenesis by powdery mildew on host leaves as revealed with the digital microscope.     

A comparison of the phenotype of dendritic cells derived from discrete Peyer's patch macrophages of non-infected and Toxoplasma gondii infected mice

A comparison of the expression of surface membrane antigens between dendritic cells (DC) derived from Peyer's patch macrophages (DPP-DC) of non-infected and Toxoplasma gondii (T. gondii) infected mice was performed. C57BL/6J mice aged 6-8 weeks of both sexes were infected orally with a 0.5 ml suspension containing 2 x 10(4) bradyzoites of the Beverley strain of T. gondii, sacrificed on day 8 and DC generated using discrete Peyer's patch macrophages (DPP-M?) as progenitor cells. When a comparison of the expression of surface membrane antigens between the antigen presenting cells (APC) obtained from discrete Peyer's patches of non-infected and T. gondii infected mice was carried out, no significant differences were observed in the macrophage progenitor and DC populations expression of F4/80, DEC-205, CD11c, CD80 (B7-1) and CD34. However, a significant decrease in MHC class II antigen levels and a down regulation of the co-stimulatory molecule CD86 (B7-2) were noted. B7-1 appeared to be the dominant co-stimulatory ligand, whereas B7-2, which was down regulated during T. gondii infection, had a weak expression. Taken together, these results may help clarify the role of DC in the complex network regulating surface membrane antigens, as well as, their capacity for antigen uptake, processing and presentation during toxoplasmosis.     

Neutralizing test of hemagglutinating encephalomyelitis virus (HEV) in FS-L3 cells cultured without serum

FS-L3 cells, originating from porcine kidney, were used for propagation of Hemagglutinating encephalomyelitis virus (HEV) and development of a virus neutralizing (VN) test. Sera of pigs, rats, cows and dogs had VN activities to HEV. On the other hand, sera of mice, rabbits, goats, sheep, horses, cats, chickens, hamsters and human did not have measurable VN activities, although these sera had high HI activities. Our results support the idea that the VN is a more reliable measure of HEV infection than the conventionally used HI test.     

Infectivity of a Japanese isolate of <Emphasis Type="Italic">Oidium neolycopersici</Emphasis> KTP-01 to a European tomato cultivar resistant to <Emphasis Type="Italic">O. lycopersici</Emphasis>

The infectivity of a Japanese isolate of tomato powdery mildew, Oidium neolycopersici KTP-01, to tomato cultivars was examined using a resistant cultivar Grace bred in The Netherlands to O. lycopersici, which was recently proposed to be renamed O. neolycopersici. Grace was severely infected with KTP-01, and its susceptibility was similar to that on susceptible tomato cultivars Moneymaker and Ponderosa, suggesting that KTP-01 differs in pathogenicity on tomatoes from those of European and American isolates.     

Kinetics of endotoxin concentration and tumor necrosis factor-alpha,interleukin-1beta,and interleukin-6 activities in the systemic and portal circulation during small intestinal ischemia and reperfusion in dogs

OBJECTIVE: To determine whether small intestinal ischemia and reperfusion induces bacterial translocation and proinflammatory cytokine response in either the systemic or portal circulation in dogs. ANIMALS: 17 healthy adult Beagles. PROCEDURE: The superior mesenteric artery (SMA) was occluded for 0 (group-3 dogs), 30 (group-1 dogs), or 60 (group-2 dogs) minutes, followed by reperfusion for 180 minutes; serum lactate and endotoxin concentrations and tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 activities in the systemic and portal circulation and intramucosal pH were measured at various time points. RESULTS: In group-2 dogs, TNFalpha activity was found to be significantly increased in the portal circulation, peaking at 60 minutes of reperfusion; TNF-alpha activity, in the systemic circulation, gradually increased from 60 minutes of reperfusion to the end of the experiment; however, the increase was not significant. In group-1 and -2 dogs, IL-6 activities significantly and gradually increased in the systemic and portal circulation during the reperfusion phase, and the magnitude of these increases was dependent on the duration of the ischemic phase. There were no significant changes in IL-1beta activity or endotoxin concentration in any dog group. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the our study indicate that intestinal ischemia and reperfusion leads to significant increases of the circulating TNF-alpha and IL-6 activities, depending on the duration of the ischemia phase, in the absence of detectable endotoxin in the circulation. This finding suggests that intestinal ischemia and reperfusion induces a systemic proinflammatory cytokine response in dogs.     

A gross and histopathological study of an ectopic white line development in equine laminitis

In horses with chronic laminitis, an abnormal horny structure called lamellar wedge, is generated between the hoof wall and the laminar epidermis. To be able to manage horses with chronic laminitis correctly, more information about the pathological state of this abnormal horn is required. The aim of this study was to collect and analyze objective morphological data about the abnormal horn in order to understand its morphology and development. In the study, the abnormal horn was grossly visible on the sagittal hoof section from approximately 20 days after the onset of disease. In the histological observations, the structural characteristics of this abnormal horn were similar to the white line tissue, suggesting it is an ectopic white line. Mean value of the cross-sectional area of the abnormal horn against the distal phalanx section area (A/D) was 0.29 cm(2) SD +/- 0.14 and it finally showed an eight-fold increase over the mean value of normal white line section area against the distal phalanx section area. In conclusion, a large amount of the ectopic white line is thought to be finally able to inhibit normal hoof wall growth, so that it should be resected at the optimum time when would be after one month from the onset of the disease.