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C R Wilson

Publications and source records attributed to C R Wilson.

96 records · Page 6Linked to original sources
PubMedDate not supplied

Abdominal computed radiography: evaluation of low-constrast lesions.

Computed radiography has proved useful as a localization device for computed tomography. In an attempt to evaluate computed radiography as a primary diagnostic device, 16 patients were evaluated with various degrees of gallbladder opacification following standard oral cholecystograms, and 15 patients were evaluated with renal masses, identified on standard excretory urography. Subjective evaluation of computed radiographs as compared to the standard radiographs demonstrated no diagnostic advantage to computed radiography. The poor spatial resolution of the computed radiographs was not overcome by the improvement in contrast resolution.

Cholecystography↗
PubMedDate not supplied

Rapid fluorogenic enumeration of Escherichia coli in selected, naturally contaminated high moisture foods.

An assay for the enzyme glucuronidase was used to determine the presence of Escherichia coli in selected, naturally contaminated high moisture foods. Raw pork sausage, ground turkey, and ground beef were inoculated into tubes containing the substrate 4-methylumbelliferyl beta-D-glucuronide (MUG) in lauryl tryptose (LT) medium. After incubation at 35 degrees C for 24 h, the inoculated LT-MUG tubes were examined under longwave ultraviolet light for the presence of a fluorogenic glucuronidase end product. A fluorescing tube indicated the presumptive presence of E. coli. The 10 day most probable number method of the AOAC and the LT-MUG procedure gave comparable recoveries of E. coli.

Animals↗
PubMedDate not supplied

Glucuronidase assay in a rapid MPN determination for recovery of Escherichia coli from selected foods.

Glucuronidase is present in most strains of Escherichia coli but absent in most other enteric microorganisms; therefore, an assay for this enzyme is useful for determining the presence of the organism. The substrate 4-methylumbelliferyl beta-D-glucuronide (MUG) is incorporated into either lauryl tryptose (LT) broth or EC medium; the inoculated tubes are then incubated under specified conditions and examined under longwave UV light for the presence of a fluorogenic glucuronidase end product. When compared with the 10-day most probable number (MPN) procedure of AOAC, the LT-MUG and the EC-MUG tests required 24 and 96 h, respectively, and gave comparable mean log MPN values for samples of crabmeat, sunflower kernels, and walnut pieces. However, false-positive and false-negative reactions were observed with foods tested by both of these rapid methods. Overall, method sensitivity was not compromised by using the LT-MUG rather than the EC-MUG method. Incorporation of 25 micrograms MUG/mL into LT broth resulted in diminished fluorescence of positive reactions, whereas MUG concentrations of 50 and 100 micrograms/mL provided decisive fluorogenic reactions.

Culture Media↗
PubMedDate not supplied

Recovery of Salmonella species from nonfat dry milk rehydrated under rapid and reduced pre-enrichment conditions: collaborative study.

A collaborative study was conducted to compare the relative efficiency of the AOAC rapid rehydration method with the reduced rehydration soak method for the recovery of Salmonella species from nonfat dry milk (NFDM). In the AOAC method, a 25 g sample of NFDM is rapidly rehydrated at a 1:9 sample/water ratio and mixed by swirling. After 60 min, the flask contents are adjusted to a pH of 6.8, and 0.45 mL of 1% aqueous brilliant green dye solution is added. The flasks are then incubated at 35 degrees C. In the soak method, a 25 g sample of NFDM is gently added to the sterile brilliant green (BG) water at a 1:9 sample/BG water ratio and allowed to soak undisturbed for 60 min at room temperature before incubation. Twelve collaborators analyzed 3 shipments of samples with the following results for the AOAC and soak methods: shipment 1-31 and 46 positive samples, respectively, with a 48% increase in detection by the soak method; shipment 3-45 and 66 positive samples, respectively, with a 47% increase in detection by the soak method; shipment 2--no significant difference in recovery of Salmonella species by the 2 methods. It is recommended that the official final action method for the detection of Salmonella species, 46.054-46.067, be revised to use the soak method for the analysis of nonfat dry milk.

Animals↗