Heat exchange in men and women following intravenous injection of endotoxin

An assessment was made of heat exchange during the course of an induced febrile episode following injection of endotoxin. Experiments were performed on either normal subjects or patients with recurrent fever. They were given intravenously either saline or a dose of 1 or 2 mμg Lipexal (the lipopolysaccharide of Salmonella abortus equi) per kilogram approximately 15 min before being exposed for 3–6 hr to 27.7 C air while wearing minimal clothing. Continuous measurements were made of: oxygen consumption, carbon dioxide production, core temperatures, skin temperatures, muscle surface temperature, and heat flow from the lateral surface of the upper and lower arm and the back of the hand. Three distinct patterns of reactivity were found: a) nonreactors (N = 2), b) those in whom elevated heat production preceded a rise in core temperature (N = 8), and c) those in whom thermal redistribution produced a rise in core temperature prior to an increase in heat production (N = 5). The results suggest that endotoxin may produce fever by alteration of either vasomotor control of heat redistribution or heat production at independent rates. Fever patients, in comparison to normal subjects, appeared to have an exaggerated metabolic response per equal increment in core temperatur

Note

(With the Technical Assistance of D. Thrasher)

cold; fever; temperature regulation

Submitted on December 23, 1963

Occurrence of Gram-Positive Organisms Possessing Characteristics Similar to Those of Salmonella and the Practical Problem of Rapid and Definitive Salmonella Identification

The occurrence and incidence of gram-positive organisms which possess some biochemical and serological characteristics in common with salmonellae are described. These organisms were encountered as contaminants in various food products as well as in feces. Their growth in various Salmonella enrichment media, typical Salmonella -like growth on differential selective media, biochemical similarities to Salmonella , and agglutination in Salmonella polyvalent O antiserum serve as a source of possible confusion in analyses for Salmonella . Although a definitive identification was not performed, preliminary results indicate that these bacteria closely resemble members of the genus Brevibacterium . No sanitary significance could be associated with these bacteria, because they were never found to coexist with Salmonella . The occurrence of these bacteria illustrates the pitfalls of a cursory examination for Salmonella . On the premise that ultimate identification of Salmonella rests upon serological procedures, a rapid and definitive identification of suspect Salmonella isolates is proposed, based upon reactions with polyvalent group O, group O, and Spicer-Edwards H antisera.

RESISTANCE OF SALMONELLAE ISOLATED IN 1962 TO TETRACYCLINE, CHLORAMPHENICOL, AND AMPICILLIN

Of 664 Salmonella cultures isolated during 1962 from a variety of sources in Canada, 56 (8.4%) were resistant to one or more of the antibiotics tetracycline, chloramphenicol, and ampicillin. Of the 38 serotypes studied, S. typhimurium and S. heidelberg showed a much higher proportion of strains resistant to tetracycline than did the other serotypes. The incidence of resistant strains among 335 cultures from man was 6.9%; among 74 strains from poultry, 35.1%; while among 52 strains from other animal sources only 5.8% were resistant.