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Biomedical subjects

C W Watson

Publications and source records attributed to C W Watson.

At least 19 recordsLinked to original sources

Evaluation of a commercial automated system and software for the identification of veterinary bacterial isolates.

A commercial gram-negative bacterial autoidentification plate was originally developed using bacterial isolates of human origin. Three veterinary diagnostic laboratories conducted a 2-phase trial to enhance the database for veterinary use. The first phase consisted of testing the plate with 447 bacterial isolates of veterinary origin and incorporating that data into the existing database. Emphasis was placed on the Actinobacillus, Bordetella, Pasteurella and Enterobacteriaceae groups, since the Pseudomonas taxon was quite complete. The second phase of the trial consisted of evaluating the enhanced database using 270 clinical veterinary isolates normally encountered in veterinary laboratories. For the Actinobacillus, Bordetella, Pasteurella and Enterobacteriaceae groups, 72% of the bacterial isolates were identified correctly to genus and 85% to species after 18 hours incubation. All identifications in phase 1 and phase 2 were confirmed using conventional methods.

Actinobacillus Infections↗

Isolation of Acanthamoeba sp. from a greyhound with pneumonia and granulomatous amebic encephalitis.

Acanthamoeba were isolated from a naturally occurring animal infection of granulomatous amebic encephalitis. The amebas were grown from lung lesions from a 1-year-old greyhound puppy, which was 1 of several dogs in a kennel that was affected by a progressive fatal neurologic and respiratory disease. The Centers for Disease Control, Atlanta, Georgia, confirmed the disease to be acanthamebiasis and specifically identified the amebas as Acanthamoeba culbertsoni by fluorescent antibody testing on brain tissue from the dog. The amebas were cultured initially on potato dextrose agar and on nonnutrient agar plates that were seeded with a lawn of nonpathogenic Escherichia coli. The isolate was then transferred to nonnutrient agar plates containing killed Enterobacter aerogenes and subsequently to axenic medium and cell cultures. The isolate was highly pathogenic by intranasal inoculation into 2-week-old mice.

Acanthamoeba↗

Morphometric analysis of neoplastic renal aspirates and benign renal tissue.

This study was designed to develop a practical morphometric procedure for the diagnosis of carcinoma in renal aspirates. We studied aspirates from renal cell carcinomas (grades 1-2) and normal kidneys. Video images of nuclei were traced on a high-resolution, touch-sensitive screen connected to an image analysis system. From each tracing the computer calculated nuclear perimeter length, nuclear profile area, maximal chord length, and the means and standard deviation for all measurements. Size distribution of nuclear profile areas and perimeter length in discrete bins ranged, respectively, from 30 to 80 at 10 microns2 intervals for areas and from 1 to 12 microns at 1-micron intervals for the maximum chords. The size distribution plots for the maximal chord of individual nuclei demonstrated an early narrow peak at low values for normal renal aspirates (peak located in the class ranging from 7 to 8 microns), while a broader, flatter peak with a shift to the right and a malignant tail was seen in renal cell carcinoma aspirates (peak located at 9-10 microns). These data were used for multivariate analysis to form two categories to establish a data base against which unknown cases could be tested. Multivariate analysis using a total of 14 variables yielded a value of 169.1 for the euclidean distances between the center of clusters of the neoplastic and normal renal aspirates and confirmed the classification with posterior probabilities of 1.0. From these data, automated classificatory analysis of 10 unknown cases was performed by means of the k-nearest neighbor procedure, with correct classification established in each case.

Biopsy, Needle↗

An evaluation of electroencephalographic monitoring for carotid study.

Continuous electroencephalogram (EEG) monitoring was used during 213 carotid endarterectomies in 157 patients to identify cerebral ischemia. General anesthesia was used for all patients. An intraluminal shunt was not used routinely, but was inserted in 23 operations when EEG abnormalities associated with ischemia appeared. EEG changes occurred in 31 operations (14.5 percent). Four patterns of abnormal recordings were identified and are discussed. Six patients developed ischemic EEG changes in association with hypotension during endarterectomy. In two of these patients changes appeared with a blood pressure drop of only 20 mm. Hg below preoperative levels. Four patients with internal carotid artery back pressures of 75 to 100 mm. Hg developed EEG abnormalities which disappeared after shunt insertion. Our experience emphasizes the value of continuous EEG monitoring in detecting inadequate cerebral perfusion.

Aged↗

Fine needle aspiration of osteitis fibrosa cystica.

The cytology findings of a fine needle aspiration biopsy from osteitis fibrosa cystica (brown tumor) of the rib in a patient with primary hyperparathyroidism due to parathyroid carcinoma are discussed. Many multinucleated osteoclast-type giant cells, characteristic of either osteitis fibrosa cystica or benign giant cell tumor of bone, were noted. There were also spindly or fibrillary cells with single, ovoid nuclei, probably of stromal origin.

Aged↗