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Biomedical subjects

J R Patterson

Publications and source records attributed to J R Patterson.

83 records · Page 5Linked to original sources

Preferred surgical treatment for alveolar cell carcinoma.

An analysis of our experience with 48 patients having bronchiolar or alveolar cell carcinoma is reported. The remarkable biological variability of this peripheral tumor has important surgical implications. Basically, two dominant clinical presentations occur. In the less common diffuse or multinodular form, prolonged survival is infrequent regardless of the therapeutic approach. Often these patients die from respiratory compromise due to the tumor itself. In the more common localized or solitary form the prognosis for cure is good, approximating 47% or higher. Based on the material presented, lobectomy is the preferred method of surgical treatment. In patients manifesting multinodular disease, surgical resection rarely seems warranted. The concept of preserving pulmonary tissue is stressed.

Adenocarcinoma, Bronchiolo-Alveolar↗

Exacerbation of porphyria during treatment of pulmonary tuberculosis.

Several attacks of acute intermittent porphyria complicated the treatment of a patient with pulmonary tuberculosis. To determine whether the attacks were drug-induced, the ability of a variety of antituberculous drugs to induce (delta)-amino-levulinic acid synthetase activity in a rat liver model was assessed. Pyrazinamide was found to be capable of significantly inducing amino-levulinic acid synthetase activity; the other antituberculous drugs caused either slight or no induction of amino-levulinic acid synthetase. The data suggest that pyrazinamide was capable of causing an exacerbation of the patient's porphyria. Tuberculosis, by causing debility, may also have aggravated this patient's previously latent porphyria.

5-Aminolevulinate Synthetase↗

Lidocaine blood concentrations during fiberoptic bronchoscopy.

Blood lidocaine concentrations were measured in 21 patients during routine fiberoptic bronchoscopy. In one patient, concentrations were in the toxic range. Measureable, but generally safe, concentrations were observed in the remaining patients. Cardiac and central nervous system toxicity may result from lidocaine adsorption, particularly in the seriously ill patient, although none was observed during the course of these studies.

Absorption↗

Case report: an investigation of chlortetracycline and oxytetracycline residues in suspect swine slaughtered in Manitoba, Canada, October 1987 to March 1988.

Tissue samples from 623 hogs suspected of having received antibiotic treatment were collected at federally-inspected abattoirs in Manitoba and submitted for analysis from October 1987 to March 1988. Initially, samples were screened by a multi-residue thin layer chromatography/bio-autography method, but, during the final two months of the investigation, analysis was restricted to a quantitative high performance liquid chromatography method for tetracycline antibiotics only. Sixteen animals (3%) were found with detectable tissue levels of chlortetracycline ranging from 0.10 to 1.38 ppm. One hundred thirty-eight animals (22%) were found with detectable tissue levels of oxytetracycline ranging from 0.05 to 2.07 ppm. Comparison of these levels with previously published values suggested that some producers were administering tetracyclines at therapeutic levels without observing the seven-day withdrawal period. The data generated by this study provided information for use by regulatory officials at Health and Welfare Canada in establishing specific tolerance levels for residues of the tetracycline antibiotics in animal tissue; previously, a zero tolerance had been in effect. During the study, only one hog had tetracycline residues in muscle which would have exceeded the current tolerance levels.

Abattoirs↗

Locked-in syndrome: a review of 139 cases.

Etiology, clinical manifestations and outcome were reviewed in 139 cases of "locked-in syndrome." Six cases were reported from our center and the remaining 133 cases were taken from a review of the literature. The results of this review emphasized the necessity for a comprehensive program of pulmonary management in this population. Furthermore, an effective system of communication for the patient is considered essential in the management of the "locked-in" state. Reported mortality in the cases reviewed was 60%. Overall, the prognosis for survival and recovery was found to be better in the group of patients whose syndrome was nonvascular in origin than those with a vascular etiology. Functional recovery was generally good in those patients with a vascular etiology who survived beyond 4 months while recovery occurred earlier and more completely in the nonvascular group. Thus, a program of intensive rehabilitation should be considered early in both groups in order to assist each patient in attaining the highest level of function possible as recovery progresses.

Adult↗

Determination of flunixin residues in bovine muscle tissue by liquid chromatography with UV detection.

A new and sensitive liquid chromatography-ultra violet method with a detection limit of 6 ng/g (ppb) and a limit of quantification of 15 ng/g was developed for the determination of flunixin residues in bovine muscle tissue. Flunixin in homogenized animal tissue was extracted with acetonitrile after enzyme digestion. The tissue digest (extract) was then cleaned up on a solid-phase extraction cartridge and eluted with acidified hexane. After the eluate was evaporated to dryness under nitrogen at 55 degrees C, the residue was reconstituted in 1 mL mobile phase solution and analyzed by reversed-phase gradient chromatography with UV detection at 285 nm. The method was then applied in a survey study of slaughter animals to determine whether flunixin is being used in an off-label manner for veal and beef production in Canada.

Acetonitriles↗

Determination of pentachlorophenol in animal tissues: a Canadian perspective.

Analytical methods for pentachlorophenol (PCP) residues in edible animal tissue have been reviewed, with particular reference to gas chromatographic methods of analysis. Results of analyses demonstrate that significant residues of PCP can persist for several weeks in animals exposed to contaminated bedding. National surveys in Canada have found that the incidence of PCP residues in pork in excess of 0.1 ppm was reduced from 32% of survey samples in 1981-1982 to 6.6% of samples tested in 1987-1988. An interlaboratory sample exchange among Canadian laboratories demonstrated that the PCP analytical method currently used by Agriculture Canada could be successfully transferred to other laboratories. An exchange of samples between regulatory laboratories of Agriculture Canada and the Food Safety and Inspection Service of the U.S. Department of Agriculture (USDA) demonstrated equivalency of results for the 2 methods currently used in the respective laboratories, with relative standard deviations for analytical results ranging from 4.4 to 22.2%.

Animals↗