Lesions resulting from attempted Shwartzman reaction in turkey poults inoculated with Pasteurella multocida lipopolysaccharide.

Five-week-old turkey poults were given two consecutive intravenous injections (24 hours apart) of highly purified Pasteurella multocida lipopolysaccharide (LPS) in an effort to induce a generalized Shwartzman reaction. There were no gross lesions, and microscopic lesions were limited to focal hepatic necrosis with heterophil infiltration. Hepatic lesions did not differ qualitatively from lesions in turkeys given a single dose of lipopolysaccharide. Margination of heterophils in the pulmonary vasculature was observed in turkeys 4 hours after a single injection of LPS, but it was not present in turkeys given the consecutive injections of LPS. To induce a dermal Shwartzman reaction, turkeys were given intradermal injections of LPS followed by an intravenous injection of LPS 24 hours later. Although no grossly visible hemorrhagic dermal necrosis occurred, microscopic lesions, including heterophil infiltration, vasculitis, thrombosis, and necrosis, were present. Thrombosis and vasculitis were observed only in turkeys given the intravenous and intradermal LPS, whereas the other inflammatory changes were observed in turkeys given the intradermal injection of LPS and intravenous water. Prominent lymphocytic perivascular cuffing at the site of dermal injection was present in all turkeys given intradermal LPS.

Turkey macrophage and heterophil bactericidal activity against Pasteurella multocida.

Bactericidal activity of turkey macrophages and heterophils was demonstrated in an in vitro colorimetric bactericidal assay. Two vaccine strains and one field isolate of Pasteurella multocida A:3,4 and a single isolate each of Escherichia coli and Staphylococcus aureus were compared for susceptibility to the bactericidal activity of turkey macrophages and heterophils. Only P. multocida A:3,4-strain M-9 (the least virulent strain) was susceptible to macrophage bactericidal activity in the absence of specific immune serum, whereas all three P. multocida A:3,4 organisms were killed when opsonized with specific immune serum. E. coli was susceptible to the bactericidal activity of macrophages, and S. aureus was resistant. All bacteria tested were highly sensitive to the bactericidal activity of intact turkey heterophils, regardless of the opsonin treatment. Electron microscopic findings suggested that heterophils may kill extracellular P. multocida. Only S. aureus and E. coli were killed by lysed heterophils.

Resistance of Pasteurella multocida A:3,4 to phagocytosis by turkey macrophages and heterophils.

A virulent field isolate and 2 vaccine strains of Pasteurella multocida A:3,4 were compared for resistance to phagocytosis by turkey macrophages and heterophils, using in vitro assays. The least virulent vaccine strain (M-9) was phagocytosed to a greater degree than was the field isolate or the other vaccine strain (Clemson University). All 3 bacteria differed significantly from each other in the amount of capsular material present as measured by polycationic ferritin labeling and electron microscopy. Removal of the capsule with hyaluronidase resulted in a significant increase in phagocytosis of the field isolate.

Quantitative indices of clinical uremia.

The disabling, dialysis-responsive symptoms of clinical uremia primarily represent impaired functions of the nervous system. Accordingly, these studies used several quantitative electrophysiologic and cognition-dependent probes of nervous system function: peripheral nerve-conduction velocity, response latency and amplitude; electroencephalographic (EEG) power-spectrum analysis; visual evoked response latency; EEG responses to photic driving; and measures of integrated behavioral performance that stressed sustained and selective attention, reaction time, speed of decision-making, short-term memory, and mental manipulation of symbols. Probes of quanitified central nervous system function consistently revealed impairments that varied directly with the degree of renal failure, that improved following onset of maintenance dialysis, and that improved still further after successful renal transplantation. In contrast, measures of peripheral nerve function were generally unchanged. Neurobehavioral measures that are relevant to uremic symptomatology provide quantitative estimates of the clinically significant, whole-organism biologic effects of renal failure and its several treatments. Applications of such measures in studies of symptomatic states other than uremia are indicated also.