Rodney R. Beard

PATHOGENESIS OF COCCIDIOIDOMYCOSIS WITH SPECIAL REFERENCE TO PULMONARY CAVITATION

Excerpt It is now accepted that human infections ofCoccidioides immitisare usually acquired by inhaling the chlamydospores and arthrospores of the fungus. Occasionally the portal of entry may be by...

Carbon Monoxide and Human Functions

Around the beginning of the century, several great investigators discovered much of what we know about carbon monoxide (CO). C. G. Douglas, J. S. Haldane, James Lorrain Smith, Yandell Henderson, and J. B. S. Haldane made tremendously insightful investigations which clarified many of the issues concerning CO; many of the questions which they raised and left unanswered are still being explored. Their chemical and physiological studies were very thorough. However, they did not got deeply into the effects of carbon monoxide upon behavior. Indeed, their tendency was to underrate the potential toxicity of CO, Haldane having on occasion referred to “the 30 percent saturation of the blood which was necessary for any noticeable symptoms of CO poisoning” (Haldane and Priestley, 1935). It may be pertinent to suggest that the frame of mind in which this early work was carried out was characterized by admiration for the marvels of animal adaptations, and particularly, the ability of man to make physiological adjustments which permit him to continue to function effectively under circumstances of extreme physical stress. The question being asked was, “How much can man tolerate without any important change?,” and the emphasis was upon chemical alterations which could be measured with some precision, rather than upon symptoms which could not be reliably quantified or upon behavioral changes, for which an adequate understanding and vocabulary was only beginning to be developed.

Effects of sulfanilamide, phenothiazine, and thionol in experimental trichinosis.

Conclusions (1) A rather large amount of sulfanilamide, 0.96 g per kilo of body weight daily, used over a period of 6 weeks reduced the number of trichinella encysting in the muscles of rats by 55%. (2) The continuous use of phenothiazine, in a dosage approximately one-tenth that of sulfanilamide, over a period of 6 weeks reduced the severity of trichinous infection in rats by 74% and warrants further experimentation. (3) Thionol is of little use in reducing the severity of trichinous infestation in rats.

Toxicological Appraisal of Carbon Monoxide

The draft Technical Report on Air Quality Criteria for Carbon Monoxide shows thorough familiarity with the relevant toxicological studies. The authors selected materials for discussion very judiciously. They present the pertinent information in sufficient detail to permit an independent judgment of its significance, in most instances. The conclusions are firmly based on the information which is presented.

Further Observations of Phenothiazine in Experimental Trichinosis.

Conclusions Contrary to our previously published observations, no evidence was found that phenothiazine administered prior to, concurrent with, or after infestation, has any appreciable value in experimental trichinosis in rats. There is strong evidence of a sex variation in the susceptibility of rats to Trichinella infection, females having higher resistance as indicated by the number of encysted Trichinella found after feeding standard doses of larvae.