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Biomedical subjects

J Howell

Publications and source records attributed to J Howell.

85 records · Page 5Linked to original sources
PubMed1965

Symptoms and pathology produced by toxic Microcystis aeruginosa NRC-1 in laboratory and domestic animals.

Toxicity tests with lyophilized M. aeruginosa NRC-1 cells have been conducted using mice, guinea pigs, rabbits, chickens, ducks, two calves and one lamb as the test animals. The symptoms and pathological changes are described. On an equivalent weight basis it required three to five times the oral dosage to kill the large animals and birds as it did to kill the laboratory animals. The symptoms were less pronounced and the survival times were longer in the more resistant animals. Enlargement and congestion of the liver with necrosis of the hepatic cells were constant and pathognomonic. These findings are in general agreement with the observations of other workers who have examined the toxicity of naturally occurring Microcystis waterblooms. The toxicities and structures of microcystin and of six other biologically active cyclic polypeptides are summarized. The pathological effects produced by microcystin in laboratory and domestic animals resemble those produced in man but differ from those produced in animals by the toxic peptides of Amanita phalloides.

Animals↗
PubMedDate not supplied

Clinical provocative tests used in evaluating wrist pain: a descriptive study.

The purposes of this clinical study were to standardize the method of examination and provocative testing of painful wrists and to compare retrospectively the results of these tests with the arthroscopic findings of three independent hand surgeons. This article operationally defines the scaphoid shift test (SST), the ballottement test (BALLOT), and the ulnomeniscotriquetral dorsal glide test (UMTDG); describes the clinical and arthroscopic examination method; and analyzes the sensitivities, specificities, and predictive values of these provocative tests relative to the arthroscopic findings in 50 painful wrists. Each patient had unspecified wrist pain of at least 4 weeks' duration and was examined by one certified hand therapist who carried out all of the clinical provocative tests. The sensitivities for the SST, the BALLOT, and the UMTDG were 69%, 64%, and 66%, respectively. The specificities for the SST, the BALLOT, and the UMTDG were 66%, 44%, and 64%, respectively. The positive predictive values for the SST, the BALLOT, and the UMTDG were 48%, 24%, and 58%, respectively. The negative predictive values for the SST, the BALLOT, and the UMTDG were 78%, 81%, and 69%, respectively. These wrist provocative tests were efficient for identifying patients who needed a more detailed diagnostic workup and possible arthroscopic inspection. Of those patients who needed arthroscopic inspection, the provocative tests proved to be more efficient at predicting the absence of injury than at predicting its presence.

Adult↗
PubMedDate not supplied

Carbon monoxide hazards in rural Alaskan homes.

Alaska has the highest age-adjusted death rate from unintentional carbon monoxide poisoning in the nation. We conducted a study in five villages to determine carbon monoxide levels and sources. Nearly 10% (10/105) of the homes had elevated levels. Improperly vented propane Paloma water heaters were most commonly responsible and produced the highest levels of carbon monoxide. Other sources were leaking pipes from wood stoves and stoves that had been left on for several hours. We recommend that Paloma water heaters not be used where freezing temperatures create a risk for carbon monoxide poisoning, fires, and explosion. Safety education campaigns should note the risks of Paloma water heaters and defective stove pipes, and the need for increased kitchen ventilation during prolonged cooking. Medical workers need to be informed of the prevalence of carbon monoxide exposures. Homeowners can install carbon monoxide detectors, although expense and false alarms remain barriers to their use.

Air Pollution, Indoor↗