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Biomedical subjects

M R Swanson

Publications and source records attributed to M R Swanson.

9 recordsLinked to original sources

Computer analysis as an aid in identification of mycobacteria.

One hundred eighty-four isolates representing 23 species of mycobacteria were identified using computer-assisted analysis. All isolates were examined using a standard series of 12 biochemical tests. These tests were selected because of their reproducibility and ease of performance in the laboratory. Data from these tests were analyzed by a computer that had been previously programmed to process the information and make a species determination. Identifications from the probability model were compared to identifications from conventional methods. There was 96.7% agreement between the 2 methods. The computer-assisted data analysis for identification provides increased accuracy over conventional methods because a statistical probability is applied. It also requires less time. Differences in computer data between mycobacterial species are discussed.

Animals↗

The 40-Hz potential and SN10 as measures of low-frequency thresholds.

This study investigated the accuracy of threshold estimates using the 40-Hz Potential and the SN10 in the presence of elevated low-frequency thresholds. In Experiment 1, subjects with normal hearing were evaluated with ipsilateral low-pass masking to elevate low-frequency thresholds and in Experiment 2, subjects with low-frequency sensory hearing losses were evaluated. The stimuli were 500-, 1500-, and 3,000-Hz tone pips. The 40-Hz Potential and the SN10 were equally good predictors of the behavioral threshold when the low-frequency, pure-tone thresholds were elevated.

Adult↗

Validation of addition and subtraction of ABR waveforms.

Procedures that use the auditory brainstem response (ABR) to demonstrate binaural interaction, phasic differences, narrow-band derived responses, and adaptation rely on additions and subtractions of waveforms to demonstrate effects that are not evident in the raw waveforms. The purpose of this study was to validate these data manipulations by performing additions and subtractions of waveforms in cases in which the theoretical result should be no difference potential and in cases in which the theoretical result should be a difference potential. The results indicate that additions and subtractions of ABR waveforms are valid data manipulations.

Adult↗

Antibiotic resistance of members of the genus Salmonella isolated from chickens, turkeys, cattle, and swine in the United States during October 1981 through September 1982.

Members of the genus Salmonella isolated from chickens, turkeys, cattle, and swine and submitted to the National Veterinary Services Laboratories for serotyping during October 1981 through September 1982 were tested for sensitivity to 12 antibacterial drugs. A total of 3,500 isolates was tested. A high rate of drug resistance was observed. Three cultures were resistant to each of the drugs and 30% were resistant to each drug except chloramphenicol, cephalothin, and gentamicin. Multiple resistance patterns were observed for 80% of the cultures with an even higher percentage in cultures from swine.

Animals↗

Papillary-cystic neoplasm of the pancreas.

A case of an unusual pancreatic tumor with a characteristic papillary-cystic microscopic morphology is presented. Review of four previously reported similar cases suggests a distinct clinical picture of a large abdominal mass occurring in a young person which apparently, after resection, does not rapidly recur. The histopathology of this tumor consists of papillary and cystic patterns, regular homogeneous cells with a few mitoses, glassy eosinophilic cytoplasm, and mucin and PAS positivity. Ultrastructural detail, including eccentric nucleoli, numerous mitochondria, sparse endoplasmic reticulum, and little evidence of secretory activity, suggests a duct cell origin for this rare tumor.

Adolescent↗

Results of parathyroidectomy for autonomous hyperparathyroidism.

Autonomous hyperparathyroidism occurred in 15% of 152 patients maintained by long-term home dialysis during the past nine years. Twenty-two patients with elevated serum parathormone levels and progressive bone disease in the presence of normal serum phosphate and calcium levels were treated by subtotal parathyroidectomy. All had parathyroid hyperplasia. Eighteen of the 22 patients are presently alive and undergo dialysis. Symptoms of bone pain, pruritus, and muscle cramps had improved in three fourths of the patients. The serum parathormone level decreased from a preoperative average of 576 muLEq/mL to an average of 188 muLEq/mL postoperatively. All 18 patients, observed for six to 77 months, showed improvement in x-ray films of their bone disease. The autonomous hyperparathyroidism of end-stage renal disease is corrected by subtotal parathyroidectomy, and the effect is sustained.

Adult↗

Haemagglutination-inhibiting antibodies against swine influenza and Hong Kong influenza viruses in swine sera in the USA.

Previous reports have established that swine in the midwestern states of the USA have a high incidence of classical swine influenza and that swine become infected with Hong Kong-like influenza viruses when these are prevalent in the human population. This investigation was undertaken to estimate, on the basis of 2245 sera collected randomly from swine going to slaughter in the USA during the summer months of 1974, how many of the animals had haemagglutination-inhibiting (HI) antibodies against swine influenza and Hong Kong influenza viruses. Based on HI titres of 20 or greater, our serological survey revealed that swine influenza virus infection was widespread throughout the USA, since 20.45% of the sera tested had positive HI titres. However, serological evidence of infection of swine with Hong Kong-like viruses was present in only 2.63% of the sera tested.

Animals↗