Results of Treatment of Thyrotoxicosis after Postoperative Relapse

Ninety patients who had a recurrence of thyrotoxicosis after thyroidectomy have been reviewed. All 10 patients who had a second operation and 18 out of 20 patients treated with a full course of antithyroid drugs relapsed. These results differ greatly from the results of treatment of the first episode of thyrotoxicosis, whether by thyroidectomy or antithyroid drugs. Radioiodine is the treatment of choice in this group of patients, despite the high incidence of hypothyroidism.     

Swimming mechanisms in nereidiform polychaetes

New observations of the swimming of several species of nereidiform polychaete are presented and the parameters of body motion analysed. It is shown that there are theoretical limits to the values of these parameters outside which propulsion by the wave motion of the body is impossible. Many of the observations do fall outside them. This is because of the effect of the beating parapodia. Kinematic considerations are introduced to show how the wave of parapodial activity is related to the wave motion of the body. Dynamic considerations lead to an estimate of the minimum Young's modulus of the parapodia for pure parapodial swimming, lower values being possible for a combination of body-wave and parapodial swimming. The speeds achieved by different methods of swimming are discussed for the species that have been examined.     

Pyrogenic Responses to Staphylococcal Enterotoxins A and B in Cats

Pyrogenic responses, ranging up to 4.8 F, were induced in cats by oral administration of highly purified staphylococcal enterotoxin B in doses from 10 to 100 mug/kg. Fever was a more sensitive indicator of intoxication than was emesis. Highly purified preparations of enterotoxin A, whether administered intravenously (0.01 to 1.0 mug/kg), orally (10 to 25 mug/kg), or into the cerebral ventricles (0.005 to 0.020 mug in 0.20 ml), were also pyrogenic in cats. Tolerance to the pyrogenic activity was produced by repeated intravenous injection of a given dose of enterotoxin A but not by repeated intracerebroventricular injection. Enterotoxin A was more potent than enterotoxin B after intravenous injection in causing both fever and emesis. Cross-tolerance could not be demonstrated between enterotoxin A and enterotoxin B or Salmonella typhosa endotoxin. This lack of cross-tolerance plus the inability of large oral doses (100 to 4,700 mug/kg) of endotoxin to cause fever or emesis indicate that the reported responses were attributable to the specific toxins administered and not to contamination by other pyrogens.