Use of enzyme-linked immunosorbent assay to detect potato leafroll virus in field grown potato,cv. Russet Burbank

Use of enzyme-linked immunosorbent assay (ELISA) in detecting potato leafroll infections in field grown potato, cv. Russet Burbank, was studied from 1986 to 1988 at Rosemount, Minnesota. The objective was to determine relative reliability of current season foliage ELISA, tuber tissue ELISA, and tuber progeny foliage ELISA. Serological tests were most accurate when foliage of tuber progenies was tested. ELISA underestimated total leafroll infection when current season foliage from the inoculated plant was used, in those plants inoculated during late tuber bulking stage. Current season foliage ELISA tests using newly expanded terminal leaflets were more reliable than were tests using older leaflets. Leafroll infection was detected in the current season foliage and tuber progenies (tuber tissue as well as tuber progeny foliage) of some plants seven days after inoculation. Most current season foliage infections were detected by day 14–28 depending on year. Differences among years were most likely caused by variation in quality of virus source plants and numbers of vectors used in inoculation. ELISA tests on tuber tissue were almost as effective as ELISA tests on tuber progeny foliage in detecting potato leafroll 20 days after inoculation, but ELISA on tuber tissue substantially underestimated infection if plants were sampled earlier. Maximum percent tuber infection occurred 20 days or more after inoculation. Movement of the virus from the inoculated stem to other stems decreased with increased plant age at inoculation. Percent infected tubers declined with increased plant age at inoculation. Action thresholds developed for aphids in managing potato leafroll virus should take into account the temporal change in percent infected tubers.     

Cavity and bark nesting bird response to partial cutting in Northern conifer forests

We investigated whether partial cutting used to mimic small-scale natural disturbances could maintain cavity and bark nesting breeding birds. We assessed changes in the relative abundance of cavity nesting birds in two intensities of partial cutting, compared to uncut and clearcut stands, 9 years post-treatment. We then examined the relationship between forest structure and nesting abundance (stand scale) and compared characteristics of used nest and forage trees to unused trees (tree scale). The relative abundance of most species was highest in either heavy removal or light removal treatments 9 years post-harvest. Brown creepers were most abundant in uncut, and red-breasted sapsuckers were most abundant in clearcut and heavy removal treatments. The proportion of deciduous trees and the density of dead trees were the best predictors of nest abundance. Individual nest tree use was predicted by the presence of large deciduous trees with broken tops and early to advanced stages of decay. Forage tree use was predicted by the presence of large conifer trees in advanced stages of decay. To maintain breeding habitat for cavity nesters, we suggest that forest managers retain the specific structural attributes required for nesting, but also the diverse forest conditions required for foraging.     

Detection of Genetically Modified Soy in Doughs and Cookies

In many countries, including the European Union member states, Switzerland, Australia, New Zealand, and Japan, legislation has been set up for labeling of genetically modified organisms (GMOs) in food and feed products. To comply with these regulations, reliable detection methods are necessary. If the detection is based on DNA, a GMO analysis may contain several steps where qualitative and quantitative species-specific, GMO screening, GMO construct, and GMO line-specific polymerase chain reactions (PCRs) are used. A limit of detection (LOD) thereby defines to what extent a target molecule may be detected in a sample. In this study, cookies were made with variable levels of a soy sample containing 2 wt% Roundup Ready soy. For all PCRs described, detection limits based on dilution series and practical LODs were determined. The practical LODs are used to determine to what extent a GMO ingredient may be detected in a real food product. Results reveal that, due to the baking process, the overall DNA fragment length is reduced, rendering GMO analyses more difficult. Furthermore, Roundup Ready soy line-specific and real-time quantitative PCR are less sensitive than GMO screening PCRs, whereas just these PCRs are crucial in the decision-making process regarding the presence of GMOs in a food product. Moreover, high standard deviations and errors render the precise quantification of GMOs difficult.     

THE NORMAL XERORADIOGRAPHIC AND RADIOGRAPHIC ANATOMY OF THE COCKATIEL (NYMPHZCUS HOLLANDZS)

The purpose of the study was to provide a reference for the normal radiographic anatomy of the cockatiel ( Nymphicus hollundis ). The head, body, wing, and pelvic limb of mature males were radiographed using xeroradiographic and conventional radiographic techniques. Ten xeroradiographs and ten corresponding conventional radiographs were selected, and the xeroradiographs appropriately labeled to illustrate the normal radiographic anatomy of these regions.     

RADIOGRAPHIC FEATURES OF AORTIC BULB/VALVE MINERALIZATION IN 20 DOGS

The radiographic features of aortic bulb/valve mineralization in 20 dogs were reviewed. Extent, shape, number, and location of mineralization were recorded. Five of the dogs had additional alternate imaging examinations, including bone scintigraphy, echocardiography, and thoracic computed tomography. A necropsy was done on one dog, and the area of mineralization was evaluated using routine histology. The median age was 10 (mean 9.7; SD +/- 2.7) years. There were five males, seven neutered males, one female, and seven neutered females. The breeds were: Irish setter (6); rottweiler (7); chow-chow (1); miniature dachshund (1); borzoi (1); English setter (1); English springer spaniel (1); great Dane (1); and greyhound (1). Dogs with both right and left lateral radiographs (n = 17) had mineralization visible on both views, more conspicuously on the right lateral radiograph (n = 12). Aortic bulb mineralization was identified on the ventrodorsal radiograph of only one dog. On lateral radiographs, the aortic bulb mineralization was localized within the 4th intercostal space and in the craniodorsal quadrant of the cardiac silhouette. In nine of the dogs, there were complex or multiple mineralizations and in 11 dogs, there was a single curvilinear mineral opacity oriented in a caudoventral to craniodorsal direction. In all radiographs, the mineralization was in the expected position of the aortic bulb, and echocardiography (n = 4), spiral computed tomography (n = 2), and necropsy (n = 1) confirmed that the mineralization was within the aortic bulb. Clinical pathologic data of the dogs suggested no reason for metastatic mineralization. Exact etiopathogenesis of the lesions were not determined in this study. Based on the histologic findings in one dog, the mineralization seen in the aortic root is similar to a form of dystrophic mineralization called Monckeberg's calcific arteriosclerosis in humans. No clinical signs attributable to the mineralization were observed.     

Evaluation of the effect of urine dip vs urine drip on multi‐test strip results

Standard operating procedures, including World Health Organization guidelines for packed cell volume, are established for in‐clinic laboratory tests. No independent, evidence‐based guidelines exist for dipstick urinalysis; however, manufacturer's instructions state to dip the stick into urine. In veterinary medicine, small volume urine samples could preclude dipping; therefore, a single drip per pad from a pipette or syringe is often performed. This study aimed to examine the differences between these two urine application methods prior to analysis, with the hypothesis that the method type would not effect on test results of dipstick analysis. To standardize the strip analysis method, a Siemens Clinitek Status + analyzer was used with Multistix10SG dipsticks. Three investigators tested urines from 53 dogs with a range of diseases by both methods. Results were assessed for the degree of agreement between the methods and within method variability. Overall, the agreement between methods was high. Within each method, the drip method variability was higher than that of the dip method (P = 0.012). Disagreements between methods were present, with pH and blood having the lowest agreement levels. Glucose was more likely to be positive on the drip compared with the dip methodology. This study demonstrates potential clinically relevant differences between the two methods and a higher level of variability with the drip methodology. Therefore, while the drip method could be used for practical reasons (eg, low sample volumes), this study supports the manufacturer's recommended method of dipping the dip stick into urine rather than dripping urine onto each pad with a pipette or syringe.     

Extraction and purification of isoflavones from soybeans and characterization of their estrogenic activities

Soybean isoflavones have multiple beneficial health effects especially on estrogen-deficient diseases such as menopausal symptoms. In this study, isoflavones were produced from soybean flour, and the extraction and purification parameters were optimized to give a high yield of total isoflavones, about 0.62 mg of aglycones/g of soybean flour, which is >2 times the initial yield. HPLC analysis and MTT cell proliferation assay using MCF-7 cells revealed that the product thus obtained not only contained a high content of isoflavone aglycones but also had estrogenic activity. MTT data also revealed that both genistein and daidzein exhibited estrogenic effects at lower concentrations and antiproliferative effects at higher concentrations, and 1 microM genistein and 10 microM daidzein exerted significant estrogenic activities, which were not more than that of the endogenous level of 17beta-estradiol (E2). The production method developed can be used as a guideline for manufacturing soy isoflavones, and the MTT assay was demonstrated to be suitable for quality control on isoflavone products. The results on the estrogenic properties of isoflavones can be used as reference data for their effective and safe usages in estrogenic therapy.