The presence of double-stranded RNAs in <Emphasis Type="Italic">Alternaria alternata</Emphasis> Japanese pear pathotype is associated with morphological changes

Strains of the Japanese pear pathotype of Alternaria alternata were screened for double-stranded RNAs (dsRNAs). Four strains had several dsRNAs; strain N18 was associated with several dsRNAs and had impaired growth phenotypes such as irregular mycelium and abnormal pigmentation. We isolated dsRNA-cured isolates from strain N18 by single-conidium isolation. The dsRNA-cured isolates had recovered normal growth and pigmentation. Enlarged vesicles were observed in mycelial cells of the original dsRNA-carrying N18 strain. DAPI nuclear staining revealed regression of the nuclei in dsRNA-carrying N18 cells. These results indicate that the dsRNAs might have negative effects, such as apoptosis-like cell death, on the host fungus.     

Platy Quartz Phytoliths found in the Fossil Forest Deposits,Axel Heiberg Island,Northwest Territories,Canada

The occurrence of quartz particles having a platy morphology found in the white layers within the fossil forest deposits of Axel Heiberg Island, was further confirmed by optical and electron microscopic examinations. The platy quartz crystals were concentrated in the finer fractions. The δ ₁₈O values of fractions enriched in platy quartz crystals ranged from +13.7 to +16.6 %₀. These values were higher than those obtained for coarser fractions. The platy morphology and crystallographic character of the quartz particles concentrated in the finer size fractions are uncharacteristic both of aerosol derived material and of secondary silica. These findings and information available for the paleoenvironment of the study area favor a biogenic origin for the platy quartz. The oxygen-isotope data are consistent with this hypothesis.     

Supercritical carbon dioxide extraction of turmeric (Curcuma longa)

Turmeric oil was extracted from turmeric (Curcuma longa) with supercritical carbon dioxide in a semicontinuous-flow extractor. Extraction rate was measured as a function of pressure, temperature, flow rate, and particle size. The extraction rate increased with an increase in CO(2) flow rate and with a reduction of particle size. The effect of pressure and temperature on turmeric extraction suggested the use of higher pressure and lower temperature at which solvent density is greater and thus the solubility of the oil in the solvent is greater in the range of 313-333 K and 20-40 MPa. The major components ( approximately 60%) of the extracted oil were identified as turmerone and ar-turmerone by GC-MS.     

Oxidative dimers produced from protocatechuic and gallic esters in the DPPH radical scavenging reaction

DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging reactions of protocatechuic and gallic acids, and their methyl esters, have been investigated by NMR. In acetone, methyl protocatechuate was gradually converted to a Diels-Alder adduct of two molecules of the intermediate quinone in the reaction with DPPH radical, whereas methyl gallate rapidly gave a symmetrical dimer via a putative quinone precursor. Both dimers are rather unstable and their structures have been deduced by in situ NMR measurements of the reaction mixtures. Gallic acid also gave a corresponding symmetrical dimer in the same reaction as methyl gallate, although protocatechuquinone produced from protocatechuic acid did not yield a Diels-Alder adduct, unlike its methyl ester. Interestingly, these dimer formations were not observed in methanol solution.     

Comparison of different Oncorhynchus masou virus (OMV) strains by DNA restriction endonuclease cleavage analysis.

Seven strains of Oncorhynchus masou virus (OMV) genomes were analyzed with the restriction endonucleases BamHI, EcoRI, HindIII and SmaI. The restriction patterns of OMV strain DNAs were divided into four groups. Restriction profiles of high passage strains (00-7812, 65th passage, and H-83, 60th passage) were different from those of low passage strains (00-7812, 8th passage, and H-83, 6th passage) when digested with BamHI, HindIII and SmaI. However, no difference was observed between the restriction patterns of high and low passage viral DNA with EcoRI. There was no distinct difference observed between the restriction patterns of tumor tissue-derived and coelomic fluid-derived strains. By using 32P-labelled DNA of standard OMV (strain 00-7812) as a probe, most of the fragments of other OMV strain DNAs were hybridized.     

Extracellular virulence factors of fish Vibrio: relationships between toxic material, hemolysin, and proteolytic enzyme

Biological activities of cell-free culture filtrate of 3 virulent strains of fish Vibrio were examined to determine the relationship to the pathogenesis of fish vibriosis. Among the 3 strains examined, V anguillarum strains NCMB6 and NCMB571 produced hemolysin and protease, whereas V ordalii strain N7802 did not. Culture filtrate of strain NCMB571 were lethal to rainbow trout and produced a cytotoxic effect on fish cell line. Results revealed that the extracellular products may be involved in the pathogenesis of fish vibriosis.     

Field trials on a live bovine respiratory syncytial virus vaccine in calves.

Field trials were carried out in calves using a live bovine respiratory syncytial (BRS) virus vaccine prepared from the attenuated BRS virus, strain rs-52. Two hundred seventy-five and 353 calves were vaccinated intranasally and intramuscularly, respectively. No undesirable postvaccinal reactions were observed in the vaccinated calves. Of the serum neutralizing (SN) antibody negative calves 89.7% (26/29) and 92.8% (90/97) developed SN antibody 1 month after intranasal and intramuscular vaccination, respectively. Most of the calves having SN antibody titers of 1:1 or 1:2 at the time of vaccination showed a significant increase in SN antibody titer. About 70% and 90% of the calves vaccinated intranasally and intramuscularly, respectively, maintained SN antibody for 6 months after vaccination. In a field trial, a natural BRS virus infection occurred about 5 months after the start of the trial. Ten of the 16 unvaccinated control calves showed respiratory symptoms due to BRS virus infection. On the contrary, all of the 68 vaccinated calves exhibited no symptoms at all, indicating efficacy of the vaccine.