Development of a DNA Macroarray for the Detection and Identification of Fungal Pathogens Causing Decline of Young Grapevines.

Young vine decline (YVD) is a complex disease caused by at least 51 different fungi and responsible for important economic losses to the grapevine industry worldwide. YVD fungi are known to occur in planting material. Hence, detection prior to planting is critical to assure longevity of newly established vineyards. A DNA macroarray based on reverse dot-blot hybridization containing 102 oligonucleotides complementary to portions of the ß-tubulin region was developed for detection of YVD fungi. Specificity of the array was first evaluated against 138 pure fungal cultures representing 72 different taxa from nine genera, including 37 YVD species. In total, 61 species, including 34 YVD pathogens, were detected and identified by the array. The detection limit of the array was below 0.1 pg of genomic DNA. The array was validated against artificially inoculated canes and soil and commercial planting material, with the latter showing a high incidence of YVD fungi in nursery plants otherwise not detected by traditional plating and culturing. This DNA array proved to be a rapid and specific tool to simultaneously detect and identify most YVD fungi in a single test, which has the potential to be used in commercial diagnostics or by the grapevine nursery industry to determine the health status of the planting material.

Reduction of nitrogenase Fe protein from Azotobacter vinelandii by dithionite: quantitative and qualitative effects of nucleotides, temperature, pH and reaction buffer.

Oxidized Fe protein from Azotobacter vinelandii (Av2(0)) was reduced by dithionite (DT) in the absence and presence of nucleotides, over the temperature range 10-40 degrees C, over the pH range 7-8, and in various buffers--inorganic phosphate, TES, HEPES, and Tris. The reduction of each species of Fe protein--Av2(0), Av2(0)(MgATP)2, and Av2(0)(MgADP)2--was resolved into at least three exponential phases, with relative amplitudes of each phase varying over the range of experimental conditions, suggesting a dynamic population shift of kinetically distinct species. The rapid phase of Av2(0) reduction predominated at low temperature and pH, and in Tris buffer; rapid Av2(0)(MgATP)2 reduction was favored at high temperature and pH, and in phosphate buffer; and Av2(0)(MgADP)2 reduction was favored under more physiologically relevant conditions of 20 degrees C, pH 7.5, and in phosphate buffer. The rates of reduction of Fe protein species did not change with buffer, but temperature and pH do have an effect on the rates. With the appropriate constants, an empirically derived equation estimates the rate of Fe protein reduction at any temperature and pH within the limits 10-40 degrees C and pH 7-8, for a given species of Fe protein, and a given phase of the reaction. At 23.0 degrees C and pH 7.4, the rate of the dominant phase of Av2(0) reduction is 1.9 x 10(8) M(-1) s(-1). Under the same conditions, the rates of the two dominant phases of Av2(0)(MgATP)2 reduction are 1.2 x 10(6) and 1.5 x10 (5) M(-1) s(-1); and the rate of the dominant phase of Av2(0)(MgADP)2 reduction is 3.5 x 10(6) in M(-1) s(-1). Thermodynamic activation parameters for each phase of reduction were calculated. No breaks in the Arrhenius plots for any Fe protein species were observed.

Occurrence of Turnip Yellow Mosaic Virus on Oriental Cruciferous Vegetables in Southern Ontario, Canada.

Turnip yellow mosaic virus (TYMV) has been reported throughout Europe, New Zealand, and Australia. In 1994, this virus was identified in two field plantings of Bok Choi and one planting of Pak Choi (Brassica campestris Chinensis group var. communis) in Durham and Haldimand-Norfolk counties, respectively. In early October, approximately 25% of the plants were infected at each site. Both the striped flea beetle (Phyllotreta striolata (F.)) and the crucifer flea beetle (P. Cruciferae(Goeze)), reported vectors of the virus (1), were present at each site. Infected plants exhibited bright yellow to yellow-green mosaic mottling and often showed chlorotic lesions on the lower leaves. Vein clearing was also seen on several plants. Plants were often coinfected with turnip mosaic virus. Four symptomatic plants were taken from each field site for testing. Spherical virus particles (28 nm) were identified as TYMV by electron microscopy following post-antibody decoration and enzyme-linked immunosorbent assay with the TYMV Agdia test kit. Symptoms were reproduced on both Bok and Pak Choi by mechanical inoculation into healthy plants. Extended host range susceptibility tests with 14 differential hosts were consistent with those reported in the VIDE database (1). This virus, in the presence of the flea beetle vectors, may pose a threat to susceptible traditional cruciferous vegetables grown extensively in this area. Reference: (1) A. A Brunt et al., eds. Plant Viruses Online: Descriptions and Lists from the VIDE Database. Version: 16th January 1997.

A cart cage for transferring macaques, capuchins, and small dogs.

A novel mobile monkey transport cart cage allows ease of handling, safety, secure holding, good visual access to the monkeys, room for large macaques, and ease of assembly, all at a modest cost.

Successful implementation of Maximum Surgical Blood Order Schedule.

A Maximum Surgical Blood Order Schedule (MSBOS) is a schedule of commonly performed elective surgical procedures listing the maximum number of units of blood to be crossmatched preoperatively. A MSBOS reduces the preoperative crossmatching of blood in surgical cases in which there is less likelihood of blood transfusion. The reduction in crossmatched units of blood saves hospital time and money. This study presents the steps required to institute a MSBOS. Savings in reduced crossmatch charges were calculated. After a review of 1400 operations, a MSBOS listing 35 operative procedures was established at the Medical Center of Central Georgia. Staff compliance was greater than 99%, crossmatch to transfusion ratio was reduced from 5:1 to 2:1, and our annual savings was greater than $110,000 in reduced crossmatch charges.

Pressor response buffering by beta-adrenergic and cholinergic vasodilation in tranquilized dogs.

Buffering of alpha-receptor-mediated pressor responses by beta-adrenergic or cholinergic vasodilation in tranquilized, chronically instrumented gos was investigated. Increases in aortic pressure were produced in the same animal by intravenous injections of phenylephrine in the control state and in three successive experimental states by 1) pacing the heart to remove the reflex capability to lower heart rate, 2) pacing the heart and beta-blockade to remove beta-adrenergic vascular buffering, and 3) beta-blockade plus atropine to also remove cholinergic vascular buffering. The pressor response in each experimental state was greater than that in the state preceding it. With the combined beta-adrenergic and cholinergic blockade, the pressor response to an alpha-receptor stimulation was three times greater than that of the control state. From an analysis of the components of the pressor response, cardiac output, and peripheral resistance, it is suggested that normal buffering of an alpha-mediated pressor response may include beta-adrenergic and cholinergic vascular dilation in addition to a decrease in heart rate.

Vagal afferent and efferent contributions to the inhibition of food intake by cholecystokinin.

To assess the role of subdiaphragmatic vagal afferent and efferent fibers in the mediation of the inhibition of food intake by cholecystokinin (CCK), we compared the ability of a dose range (1-16 microg/kg), of CCK to affect 30-min liquid glucose (0.125 g/ml) intake in rats with either total subdiaphragmatic vagotomy, selective subdiaphragmatic vagal deafferentation, selective subdiaphragmatic vagal deefferentation, or sham surgery. Selective vagal deafferentation and deefferentations were produced by combinations of unilateral subdiaphragmatic vagotomy and contralateral afferent or efferent rootlet transection as fibers enter the caudal medulla. CCK produced a dose-related suppression of glucose intake in sham animals, and this action was eliminated in rats with total subdiaphragmatic vagotomy. CCK suppression of intake was attenuated in rats with vagal deafferentation, such that there was a loss of sensitivity to CCK. Vagal deefferentation resulted in lower levels of baseline intake and a truncation of the feeding-inhibitory actions of CCK. These data demonstrate that CCK's suppression of intake depends on actions of both vagal afferent and efferent fibers. We interpret these data as suggesting that 1) the actions of low doses of CCK depend on activation of vagal afferent CCK receptors and 2) the greater efficacy of higher CCK doses is the result of the potentiation of these vagal afferent actions due to local physiological gastrointestinal effects of the peptide that rely on vagal efferent input.

Renal failure in infectious mononucleosis.

An 18-year-old man developed generalized lymphadenopathy and interstitial renal disease which progressed to irreversible renal failure. Serologic studies evidenced the recent onset of infectious mononucleosis, and prior exposure to Epstein-Barr virus was demonstrated. Lymph node, liver, and renal biopsies showed mononuclear cell infiltration consistent with infectious mononucleosis. Although renal involvement in infectious mononucleosis rarely is severe, an association between infectious mononucleosis and renal failure is suggested in this patient.