Synthetic pyrethroids containing a C–C triple bond

The three commercial synthetic pyrethroids containing a carbon–carbon triple bond, α-ethynyl-2-methylpent-2-enyl (1R)-trans-chrysanthemate, (S)-2-methyl-4-oxo-3-(2-propynyl)cyclopent-2-enyl (1R)-trans,cis-chrysanthemate and [2,5-dioxo-3-(2-propynyl)-1-imidazolidinyl]methyl (1R)-trans-chrysanthemate are reviewed with emphasis on their inventive histories. Their chemistry and efficacy are described briefly. The relationship between stereochemistry and the biological activity is also discussed. © 1998 SCI.     

Seed heteromorphism in carolina dayflower (Commelina caroliniana Walter)

Carolina dayflower (Commelina caroliniana Walter), infesting soybean (Glycine max L.) fields on northern Kyushu Island, Japan, has seed heteromorphism; that is, it produces two types of seeds: pericarp and naked. However, there is no information about their germination behavior. The purpose of this study was to understand the germination characteristics of carolina dayflower seeds and to clarify the difference between the pericarp and naked seeds. On the shape of the seed, the pericarp seeds were significantly longer than the naked ones, with no significant difference in width or thickness. Both the pericarp and the naked seeds could germinate at >20°C, and at 30°C, their cumulative germination rate at 7 days after sowing was the highest, at >90%. Light had no effect on seed germination. The cumulative germination rate after 7 days, when the seeds had been stored dry, wet or under water at a low temperature, was significantly lower than after storage at room temperature, suggesting that a higher temperature and concentration of oxygen during the seed‐storage period affects the germination of carolina dayflower. However, there was no difference in the germination behavior between the pericarp and the naked seeds.     

Differential responses to high temperature during maturation in heat-stress-tolerant cultivars of Japonica rice

High-temperature stress during the grain-filling stage reduces grain quality of rice, and this is a serious problem in Japan, especially in the Kyushu region. To solve this problem, various heat-tolerant cultivars have been bred, such as ‘Nikomaru’, ‘Kumasannochikara’, ‘Genkitsukushi’, ‘Sagabiyori’, and ‘Otentosodachi’. When cultivated under high temperature after flowering, these heat-tolerant cultivars had lower percentages of chalky grains than in the heat-sensitive cultivar ‘Hinohikari’. All the heat-tolerant cultivars markedly decreased the nonstructural carbohydrate content in the stem under the high temperature compared to control condition during early grain-filling stage, which is considered to be a common trait of heat tolerance. Notably, ‘Sagabiyori’, ‘Genkitsukushi’, and ‘Nikomaru’ maintained a nucellar epidermis at 17 days after flowering (DAF) under high temperature, whereas the nucellar epidermis disappeared in ‘Hinohikari’. In addition, the expression of AGPS2b, thought to be a rate-limiting enzyme in starch synthesis, in ‘Kumasannochikara’, ‘Otentosodachi’, and ‘Nikomaru’ did not decrease under high temperature, whereas ‘Hinohikari’, ‘Sagabiyori’, and ‘Genkitsukushi’ could not maintain expression of the gene at 17 DAF. Moreover, the expression of Amy3E, a starch-degradation-related gene considered to induce grain chalkiness, in ‘Kumasannochikara’ at 17 DAF was not increased by high temperature. These results suggest that the heat-stress-tolerant cultivars have various mechanisms for dealing with high-temperature stress.     

Experimental sensitization with Japanese cedar pollen in dogs

Japanese cedar pollinosis is a type I allergic disease mediated by immunoglobulin E (IgE) antibodies to Japanese cedar (Cryptomeria japonica) pollen antigen (CPAg). By using 22 dogs consisting of 20 dogs aged 3 months and 2 dogs aged 3 years, immunization was performed by subcutaneous injections of CPAg with aluminum hydroxide gel. Variable levels of CPAg-specific IgE antibody response were detected in 21 of the 22 immunized dogs two weeks after the second immunization. This study provided an experimental sensitization system with CPAg in dogs, which will be useful for further immunological studies on Japanese cedar pollinosis.     

Locally synchronized synaptic inputs

Synaptic inputs on dendrites are nonlinearly converted to action potential outputs, yet the spatiotemporal patterns of dendritic activation remain to be elucidated at single-synapse resolution. In rodents, we optically imaged synaptic activities from hundreds of dendritic spines in hippocampal and neocortical pyramidal neurons ex vivo and in vivo. Adjacent spines were frequently synchronized in spontaneously active networks, thereby forming dendritic foci that received locally convergent inputs from presynaptic cell assemblies. This precise subcellular geometry manifested itself during N-methyl-D-aspartate receptor-dependent circuit remodeling. Thus, clustered synaptic plasticity is innately programmed to compartmentalize correlated inputs along dendrites and may reify nonlinear synaptic integration.     

Cutaneous plasmacytoma in three golden hamsters (Mesocrietus auratus)

Spontaneously occurring cutaneous tumours in three golden hamsters were characterized using histological, immunohistochemical and ultrastructural methods. Histologically, the tumours were composed of sheets of round to oval plasmacytoid cells with eccentrically placed nuclei. Tissue sections were weakly positive for anti-B lymphocyte antigen (BLA) staining. Ultrastructurally, large amounts of rough endoplasmic reticulum in the cytoplasm were observed. BLA positivity and characteristics of ultrastructure showed the plasma cell origin.     

Excision of a feline limbal melanoma and use of nictitans cartilage to repair the resulting corneoscleral defect

A limbal melanoma was surgically removed from a 12-year-old castrated male black domestic shorthair (DSH) cat. The resulting full-thickness eye wall defect was repaired using the autologous third eyelid cartilage. The patient was followed for 85 days postoperatively, during which time there was no recurrence. Other than a small amount of fibrin and blood at the anterior lens capsule, no significant complications were seen. Use of the third eyelid cartilage as graft material following resection of a feline limbal melanoma can be effective for repairing large eye wall defects and preserving ocular function. The third eyelid proved to be a convenient source of graft material. In addition, autologous grafting can reduce the potential for iatrogenic spread of infectious agents such as feline herpes virus.     

Patchy stomatal behavior in broad-leaved trees grown in different habitats

Effects of heterogeneity in stomatal behavior on gas-exchange characteristics of leaves from four tree species growing in different climates, including temperate, tropical monsoon and tropical rain forest, were investigated by combining gas-exchange measurements and the pressure-infiltration method. Field observations indicated linear relationships between whole-leaf conductance and the ratio of infiltrated to non-infiltrated leaf area (open stomata area) in Dipterocarpus sublamellatus Foxw. and Neobalanocarpus heimii (King) Ashton in a tropical rain forest in Peninsular Malaysia, whereas the ratio of infiltrated to non-infiltrated area rapidly increased up to the whole-leaf conductance at which the entire leaf was infiltrated in Cinnamomum camphora Sieb. in a temperate evergreen forest in Japan and in Azadirachta indica Juss. in a tropical monsoon area in Thailand. These results strongly suggest small ranges in bell-shaped stomatal conductance distributions in C. camphora and A. indica and bimodal stomatal conductance distributions in D. sublamellatus and N. heimii. The values of normalized maximum carboxylation rate at 25 degrees C (V(cmax25)) derived from gas-exchange measurements were not constant, but decreased with decreasing whole-leaf conductance in D. sublamellatus and N. heimii. A gas-exchange model analysis revealed a linear relationship between whole-leaf conductance and the ratio of infiltrated to non-infiltrated leaf area for bimodal stomatal conductance distributions, whereas for bell-shaped distributions, the relationships were nonlinear. Midday depression of apparent V(cmax25) in these species was mainly caused by bimodal stomatal closure. The bimodal stomatal distribution model could also explain diurnal changes in photosynthetic assimilation and transpiration rates in these species.     

Repeatable immersion infection with <Emphasis Type="Italic">Photobacterium damselae</Emphasis> subsp. <Emphasis Type="Italic">piscicida</Emphasis> reproducing clinical signs and moderate mortality

Pseudotuberculosis is a bacterial septicaemia caused by Photobacterium damselae subsp. piscicida in several marine fish species. Yellowtail Seriola quinqueradiata is the most sensitive fish species to this disease. The internal organs of naturally infected yellowtail exhibit whitish spots, tubercle-like tissue structures, consisting of bacterial accumulations. There have been many trials for experimental infection, however adequate method of infection that reproduces moderate mortality and primary clinical signs has not yet established. Present investigation evaluated an immersion infection method by using logarithmic culture-phase bacteria resulting in higher mortality than that using stationary culture-phase bacteria. Typical white spots on the spleen and kidney were also observed constantly in dead fish. Transmission electron microscopy and fluorescent antibody microscopy showed bacterial clusters not only in the spleen and kidney but also in the blood channels in the secondary gill filaments. These results were confirmed repeatedly by plural experiments. The use of logarithmic-phase bacteria in immersion infection is an appropriate technique to reproduce moderate mortality and primary clinical signs, which will be a reliable infection method also for the challenge test of pseudotuberculosis vaccine.     

Successful management with CHOP for pulmonary lymphomatoid granulomatosis in a dog

A 3-year-old, spayed female miniature dachshund was presented for vomiting and anorexia. Thoracic radiographs and CT scan revealed abnormal pulmonary opacities at bilateral caudal lobe. Cytological analysis of the pulmonary mass revealed the presence of large lymphohistiocytic cells and small lymphocytes with occasional neutrophils and plasma cells. An open lung biopsy was performed and a diagnosis of pulmonary lymphomatoid granulomatosis (LYG) was made. The dog was administered CHOP based therapy (modified UW-25), and it survived for 1,022 days after admission. Immunohistochemistry revealed pulmonary lesions consisted of many CD79a positive B cells aggregation and proliferation with prominent angiocentric pattern. This was the first case of canine pulmonary LYG managed by CHOP chemotherapy.