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1.
The in vitro metabolism of the chiral isomers of fonofos and fonofos oxon in the presence of mouse liver mixed-function oxidase and serum esterase was investigated. The metabolism of 35S-labeled phenyl-(S)P-fonofos mediated by mixed-function oxidase took place stereoselectively, resulting predominantly in (R)P-fonofos oxon. Similarly, (R)P-fonofos was converted to (S)P-oxon. In each case, however, a significant amount of racemization occurred. Other products were diphenyl disulfide and diphenyl disulfide oxide. In addition to stereospecificity, the oxidative metabolism of (R)P-fonofos proceeded at a rate faster than that of (S)P-fonofos. Stereoselective rate differences also were observed in mouse or rat serum-catalzyed degradation of the fonofos oxon enantiomers, the (S)P isomer being degraded about twofold faster than its enantiomer. The differences in toxicities of the isomers of fonofos and fonofos oxon were consistent with the in vitro metabolism data. 相似文献
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Seddighi MR Griffon DJ Constable PD Martin-Jimenez T 《American journal of veterinary research》2007,68(2):171-177
OBJECTIVE: To evaluate effects of small intestinal submucosa (SIS) on elution properties of plaster of Paris (POP). SAMPLE POPULATION: 27 POP cylinders, 27 POP spheres, and 9 polymethylmethacrylate (PMMA) spheres. PROCEDURES: Pellets were loaded with gentamicin (50 mg/g) and divided into 7 groups of 9 beads each: PMMA spheres; POP cylinders coated with 0, 4, or 8 layers of SIS; and POP spheres coated with 0, 4, or 8 layers of SIS. Gentamicin concentration was measured 6, 12, 18, 24, 32, 40, and 48 hours and 3, 4, 5, 7, 14, 21, 28, 35, and 42 days after wrapping. Porosity was evaluated via scanning electron microscopy. Curvature factor of elution curves, total amount of drug released (TDR), time required to reach 50% of total release (TDR(t50)), and number of days with concentrations > or = 1 microg/mL were compared among groups. RESULTS: SIS decreased the curvature factor and increased the TDR(t50) and TDR of POP spheres and cylinders. Curvature factor of the PMMA-release curve remained lower than that for any POP group, but all POP groups wrapped in SIS released more gentamicin than PMMA spheres. Gentamicin concentrations remained > or = 1 microg/mL in SIS-wrapped POP and PMMA groups throughout the study. Wrapping POP in SIS minimized the increase in porosity of pellets. CONCLUSIONS AND CLINICAL RELEVANCE: Wrapping POP with SIS slows the release and increases the amount of gentamicin leaching from spheres and cylinders. All groups wrapped in SIS maintained antimicrobial concentrations greater than the minimum inhibitory concentration of most pathogens. 相似文献
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Farnaz Kordbacheh Charles L. Mohler Alan G. Taylor Anna S. Westbrook Hamid Rahimian-Mashhadi Hassan M. Alizadeh Antonio DiTommaso 《Weed Research》2023,63(1):34-44
Abutilon theophrasti (velvetleaf) is a widespread and problematic annual weed. Greenhouse and field experiments were conducted to investigate the effects of different cutting methods on the viability of A. theophrasti seeds. Three cutting methods were assessed: (1) Entire plant cut and dried (EPD)—plants were cut at soil level and dried with capsules attached on the greenhouse bench or soil surface for 4 weeks; (2) capsules detached and dried (CD)—capsules were removed from plants and dried for 4 weeks; and (3) capsules detached and tested while fresh (CF)—a control treatment. Before drying, the developmental stage (stage one, dark green; stage two, light green; stage three, yellowish-green; or stage four, black with the slightly open capsule) and age (days after flowering, DAF) of each capsule was recorded. Seed viability was measured immediately in the CF treatment and after the 4-week drying period in the EPD and CD treatments. No seeds in the EPD and CD treatments were viable when harvested at the first developmental stage (1–8 DAF) in either experiment, but 100% of seeds in the CF treatment in the field were viable when harvested at 8 DAF. In both greenhouse and field experiments, seeds attained full viability at earlier harvest ages in CF than in EPD or CD treatments, suggesting that seeds might become viable relatively early in development but lose viability if allowed to dry. These findings could be applied to optimise late-season mechanical control of A. theophrasti. 相似文献
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A study was conducted to investigate the effects of skid trail slope and traffic levels on soil disturbances at two soil depths
(0–10 and 10–20 cm). The treatments were set at four traffic levels (2, 7, 12 and 20), two slope classes (<20% and >20%) and
two soil depths (0–10 and 10–20 cm). Results show that skidder traffic, longitudinal slope and soil depth have significant
effect on soil bulk density in skid trail. Comparison of average soil bulk density in different traffic levels shows that
there are significant differences in average bulk density between different traffic levels and control (p<0.05). The average bulk densities in different slopes and soil depths are significantly increased with increase in traffic
levels, maximized at 12 passes (p<0.05), but there are no significant differences between 12 and 20 passes. The interaction effects between traffic and soil
depth are significant (F
0.05,3=0.109, p<0.001). For all traffic treatments, there are significant differences in soil moisture content between the two slope classes
and the two depths (p<0.001). However, the interaction effects between traffic levels and slope classes are not significant (p >0.05), although skidder traffic and slope affected soil moisture content. 相似文献
8.
Pentamidine treatment has been used successfully to establish immune cellular responses in recovered dogs. In this paper, we examined the appearance and disappearance of antibodies over time against crude Leishmania antigens and purified gp63 or gp70 proteins in sera from cured dogs using a Western blotting technique.Following the treatment, a pattern of antibody specificities to parasite antigens was observed in the sera of cured dogs. Antibodies to gp63 and gp70 were maintained after cure. In addition, the reaction with a 26 kD band observed during the clinical phase was no longer recognized by sera taken from recovery dogs. Interestingly, two proteins, 85 and 110 kD, not observed during the patent phase were detected by sera taken from treated dogs. Such patterns of antibody specificities to various parasite antigens might represent a useful parameter to determine the actual phase of the disease process. 相似文献
9.
Elzein S Hamid ME Quintana E Mahjoub A Goodfellow M 《DTW. Deutsche tier?rztliche Wochenschrift》2002,109(10):442-443
Four of 10 donkeys, which showed lesions simulating fistulous withers, were examined clinically with the aim to cultivate and identify the causal agent. Aspiated purulent materials were subjected to bacteriological examination. The causal organisms were recovered in Tryptic Soya agar medium when incubated aerobically at 37 degrees C for up to 5 days. These organisms were found to be actinomycetes-like, Gam positive with stable branching filaments and to form heavy aerial hyphae on colony surface. The isolated organisms ere tentatively identified as Streptomyces sp. on the basis of morphological and cultural characteristics. The initial sequences analysis of the 16S rDNA gene conformed that one of the isolates (SD551) falls within the phylogenetic clade, which encompasses the genus Streptomyces. Studies are underway to further describe the disease and its causal agent. The report represents a good evidence to incriminate Streptomyces in the aetiology of the fistulous withers. 相似文献
10.
Construction of a microarray specific to the chicken immune system: profiling gene expression in B cells after lipopolysaccharide stimulation 下载免费PDF全文
Aimie J. Sarson Leah R. Read Hamid R. Haghighi Melissa D. Lambourne Jennifer T. Brisbin Huaijun Zhou Shayan Sharif 《Canadian journal of veterinary research》2007,71(2):108-118
The objective of this study was to profile gene expression in cells of the chicken immune system. A low-density immune-specific microarray was constructed that contained genes with known functions in the chicken immune system, in addition to chicken-expressed sequence tags (ESTs) homologous with mammalian immune system genes, which were systematically characterized by bioinformatic analyses. Genes and ESTs that met the annotation criteria were amplified and placed on a microarray. The microarray contained 84 immune system gene elements. As a means of calibration, the microarray was then used to examine gene expression in chicken B cells after lipopolysaccharide stimulation. Differential gene expression was observed at 6, 12, and 24 h but not at 48 h after stimulation. The results were validated by semiquantitative polymerase chain reaction. The microarray showed a high degree of reproducibility, as demonstrated by intra- and interassay correlation coefficients of 0.97 and 0.95, respectively. Thus, the low-density microarray developed in this study may be used as a tool for monitoring gene expression in the chicken immune system. 相似文献