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Biomedical subjects

E R Davis

Publications and source records attributed to E R Davis.

15 recordsLinked to original sources
PubMed1978

Spin-trapping of the trichloromethyl radical produced during enzymic NADPH oxidation in the presence of carbon tetrachloride or bromotrichloromethane.

Utilizing the spin-trapping agent phenyl-t-butyl nitrone, a free radical has been detected which is produced from carbon tetrachloride or bromotrichloromethane during the enzymic oxidation of NADPH by rat liver microsomes. The presence of NADPH is obligatory for generation of the radical. The formation of the trichloromethyl radical-phenyl-t-butyl nitrone adduct is an enzymic process, as evidenced by the inhibition of its formation in systems containing heated microsomes and in systems containing p-hydroxymercuribenzoate. A computer-simulated ESR spectrum for the trichloromethyl adduct of phenyl-t-butyl nitrone can reproduce the essential features of the spectrum of the spin-trapped radical produced enzymically from CCl4. A mechanism is proposed for the formation of the trichloromethyl radical from CCl4 or BrCCl3.

Animals↗
PubMed1978

Acute and subacute toxicology and safety evaluation of triphenyl tin hydroxide (Vancide KS).

The acute oral LD50 in Sprague-Dawley rats was determined to be 171 mg/kg (100-295) for males and 268 mg/kg (205-344) for females. 2. A 1 ppm dietary supplement of Vancide KS for 90 days did not induce any abnormalities in weanling Sprague-Dawley rats. The parameters evaluated were serum glutamic-oxaloacetic transaminase (SGOT), hematocrit, differential white blood cell count, food consumption, and weight gain, along with histologic studies of the myocardium, spleen, liver, kidney, stomach, and small intestine. A 500 ppm diet was lethal. Weanling and older rats subjected to 1000 and 10,000 ppm diets died within 5 days. 3. Vancide KS induced no acute dermal toxicity, nor did it exhibit percutaneous absorption in New Zealand strain albino rabbits. 4. Vancide KS induced no chronic dermal toxicity in New Zealand strain albino rabbits. 5. Vancide KS was not shown to be teratogenic. It exhibited an antifertility action, especially in Sprague-Dawley rats dosed on day 1 through day 7 of timed-pregnancy. 6. Vancide KS was shown to be an eye irritant which induces corneal opacity. 7. Acute oral toxicity studies in Sprague-Dawley rats indicate that Vancide KS should be classified as a toxic substance as defined in the regulations under the Federal Hazardous Labeling Act. 8. The intravenous administration of 25 mg/kg of Vancide KS to New Zealand strain albino rabbits induced death preceded by topic convulsions. 9. Vancide KS did not induce skin sensitization in male adult guinea pigs.

Administration, Oral↗
PubMed1978

Hyperlipidemia in uremic children: response to peritoneal dialysis and hemodialysis.

Hemodialysis and hyperlipidemia have been associated in both adults and children. The present study indicates hyperlipidemia in uremic children treated with peritoneal dialysis and implies that the cardiovascular risk felt to exist with hemodialysis also exists in peritoneal dialysis. Thirty-eight children with chronic renal insufficiency or end-stage renal disease were followed serially under varying conditions of medical management, hemodialysis, peritoneal dialysis, and transplantation. Serum triglyceride concentrations in patients on peritoneal dialysis were not significantly different from those in patients on hemodialysis, but both were significantly higher (P less than 0.01) than concentrations in patients on medical management and transplantation.

Adolescent↗
PubMed1976

Effect of marihuana on hearing.

Marihuana has been said to improve hearing. Two earlier studies have supported this contention. In this investigation, marihuana or placebo cigarettes were randomly smoked by 30 subjects, 15 in each group. Before and after smoking, batteries of standard audiological tests were carried out; pure tone threshold (air and bone conduction), speech reception threshold, speech discrimination at most comfortable level, and relative acoustic impedance measurements including middle ear pressure, stapedial reflexes, compliance, tympanic mobility, and Eustachian tube function. A comparison of pre and post smoking auditory test scores did not demonstrate any significant change in auditory function in the marihuana or placebo group. However, as all subjects had normal hearing and maximum speech discrimination scores pre-smoking, it can only be concluded that smoking marihuana did not worsen the hearing--the experiments were not designed to see whether it would improve hearing.

Adolescent↗
PubMed1975

Following up the physical therapist assistant graduate; a curriculum evaluation process.

Graduates of the physical therapist assistant program at St. Mary's Junior College in Minneapolis, Minnesota, were studied to ascertain how well prepared they had been for the demands of their jobs and to discover what revisions in the program curriculum might be appropriate. Working graduates and their supervisors were surveyed to obtain information about the frequency and independence of performance of 111 tasks appropriate to physical therapy departments. The response was 90 percent. The St. Mary's curriculum was considered appropriate in most respects. More than 25 percent of the supervisors considered emphasis inadequate only for facilitation, breathing, and mat exercises. Graduates' recommended changes were more extensive, suggesting a desire to expand their knowledge. A manual was designed to guide program faculties through follow-up of their own graduates. The manual includes questionnaires, worksheets, and a guide to analysis. The authors suggest that the process may also be useful for other technical-level allied health occupations.

Clinical Competence↗
PubMedDate not supplied

Acute and subacute toxicology and safety evaluation of hexahydro-1,3,5-triethyl-S-triazine.

Acute and subacute toxicology and safety evaluation was determined for hexahydro-1,3,5-triethyl-s-triazine (Vancide-TH), a bacteriostatic and fungiastatic agent proposed for industrial use by R. T. Vanderbilt and Co., Inc. Single dose oral toxicity, subacute 14 day dermal toxicity and eye irritation studies were conducted on either the rat or the rabbit. The data obtained indicate that Vancide-TH should be classified as a "toxic, corrosive and an eye-irritating" substance as defined under the "Regulations" of the Federal Hazardous Substances Act. Since the acute dermal LD50 closely approximated the acute oral LD50 in rats, this route might constitute the most serious hazard involved with V-TH and special precautions should be exercised when handling or using this substance. Because of the severe eye-irritating action, precautions should be taken to protect the eyes when handling or using the compound; the ocular damage produced may be irreversible. The "in use" concentrations (1,000 to 10,000 ppm) produced a much lesser toxocity in animals and could be without hazard if precautions are taken.

Animals↗