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Biomedical subjects

D S Campbell

Publications and source records attributed to D S Campbell.

10 recordsLinked to original sources

Clinical and epidemiological features of neurotoxic shellfish poisoning in North Carolina.

BACKGROUND: In October 1987, a red tide due to P. brevis affected the North Carolina coast for the first time. The purpose of our study was to describe the clinical and epidemiological features of neurotoxic shellfish poisoning (NSP), an illness caused by eating shellfish contaminated with the neurotoxins of P. brevis. METHODS: Active surveillance was established for cases of NSP. A descriptive study of the NSP cases was then completed. RESULTS: Forty-eight persons, who had eaten oysters at 20 meals, met the case definition. A variety of gastrointestinal tract and neurological symptoms were reported. The illnesses were generally mild and of short duration, and there were no deaths. Forty-one (85 percent) affected persons lived in five communities located within a 70-kilometer area along the coast. Cases occurred from October 27 to December 9; 27 (56 percent) of the cases occurred before the first closure of affected shellfish waters on November 2. There was a significant increase in the illness attack rate with an increase in the number of oysters eaten. CONCLUSIONS: Routine monitoring of coastal waters for P. brevis is needed to facilitate earlier recognition of red tides, closure of affected areas, and education of the public before substantial exposure to contaminated shellfish occurs.

Adolescent

Killing of Drosophila larvae by the fields of an electrohydraulic lithotripter.

Drosophila larvae contain small gas bodies stabilized within their respiratory system. Because these bubbles are inhibited in their capacity to expand by the surrounding tissues, it is probable that they do not respond to acoustic fields in the manner described by classical cavitation theory that assumes a spherical bubble in an infinite fluid. However, just because of this inhibited expansion, they may serve as reasonable models for the gas bodies in mammalian tissues. Approximately one half of a population of Drosophila larvae is killed by exposure to 3 to 10 double lithotripter shocks with a positive pressure of 2-3 MPa. In contrast with the predictions of classical cavitation theory, adding a negative pressure to the exposure has little influence on the killing rate or its threshold pressure. The available evidence suggests that interaction of gas bodies in tissues with pressure fields and the resultant biological effects may be qualitatively different than predicted by classical cavitation theory and that positive rather than negative pressure may be a predictor of these effects.

Animals

Ciguatera fish poisoning: an outbreak associated with fish caught from North Carolina coastal waters.

Ten persons who had eaten at a seafood meal in North Carolina had gastrointestinal and neurologic symptoms suggestive of ciguatera fish poisoning. In five persons, the neurologic morbidity lasted 30 days or longer. The meal included barracuda, dolphin fish (mahimahi), and yellow-fin tuna, all of which were caught in North Carolina coastal waters. Analysis of food-specific attack rates implicated the barracuda as the probable cause of the outbreak. We believe this is the first suspected or confirmed report of ciguatera fish poisoning associated with consumption of fish harvested from mainland US coastal waters outside of Florida. Physicians treating patients with a syndrome resembling ciguatera fish poisoning should inquire about consumption of fish not only from areas where the disease is endemic but also from the southeastern US.

Adult

Computer-aided self-instruction training with hearing-impaired impulsive students.

This study explored the utility of computer-aided, self-instruction training for enhancing reflective problem-solving among impulsive hearing-impaired adolescent students. Sixteen moderate to severely hearing-impaired students were randomly assigned to either a treatment or control condition. The self-instruction treatment condition consisted of training to solve visual problems using a modified version of the LOGO computer language (REFLECT) and videotape feedback. The control condition consisted of LOGO problem-solving without self-instruction. Instruction took place over 12 weeks. On two dependent measures of impulsive problem-solving behaviors, students in the treatment condition demonstrated significantly improved problem-solving ability.

Adolescent

Identification of nuclear substrates of the cyclic AMP-dependent protein kinase in Dictyostelium discoideum.

A search for nuclear substrates of the cAMP-dependent protein kinase (cAMP-d PK) of Dictyostelium discoideum led to the identification of several such proteins. Identification was based initially on increased phosphorylation of the proteins in nuclear extracts catalyzed by added cAMP-d PK. One protein of Mr 38,000 was phosphorylated also in intact nuclei and in vivo; the amount of phosphoprotein or the level of phosphorylation increased during development. Both the Mr 38,000 protein and another substrate of Mr 195,000 were found in the nuclei of prespore and prestalk cells. Phosphorylation of other potential substrates of the cAMP-d PK was either prespore or prestalk cell-specific.

Cell Differentiation

Wolf spider bites.

Because of their dark color and hunting habits, wolf spiders (Lycosidae) are often confused with the much more dangerous brown recluse spider (Loxosceles reclusa). Unlike the brown recluse spider, wolf spider envenomation seldom causes cutaneous necrosis or systemic symptoms. In this report, two documented cases of wolf spider bites are described and the pertinent literature reviewed.

Child, Preschool

The frequency of a Norwalk-like pattern of illness in outbreaks of acute gastroenteritis.

Records of 642 outbreaks of acute gastroenteritis were reviewed to determine the proportion of outbreaks that were clinically and epidemiologically consistent with Norwalk-like virus infection. Using as our criteria stool cultures negative for bacterial pathogens, mean (or median) duration of illness 12-60 hours, vomiting in greater than or equal to 50 per cent of cases, and, if known, mean (or median) incubation period of 24-48 hours, we found that 23 per cent of waterborne outbreaks, 4 per cent of foodborne outbreaks, and 67 per cent, 60 per cent, and 28 per cent of outbreaks in nursing homes, in summer camps, and on cruise ships, respectively, satisfied the criteria for Norwalk-like pattern. Of 54 outbreaks that satisfied the criteria for Norwalk-like pattern, 14 were investigated for virus etiology. Ten of these (71 per cent) yielded serologic evidence of Norwalk-like virus infection. Norwalk-like viruses are probably an important cause of outbreaks of acute gastroenteritis. Investigation for Norwalk virus antibody in outbreaks that are clinically and epidemiologically consistent with Norwalk-like virus infection is likely to yield diagnostically useful results.

Acute Disease