Hyperbaric oxygen therapy and experimental African trypanosomiasis : in vitro effects on Trypansoma brucei gambiense, and in vivo studies on the acute infection in mice.
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| Other Authors: | , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1987.
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| Subjects: | |
| Online Access: | Link to ProQuest copy Link to OAKTrust copy |
| Abstract: | The metabolism of the bloodstream form of the African trypanosomes (the parasites causing African sleeping sickness) is altered by the availability of O$ sb2$. Therefore, it was suspected that O₂ administered under high pressure (OHP) would have dramatic physiological effects on both the parasite and the host. Mice experimentally infected with Trypanosoma brucei gambiense were exposed to O₂ at 3 atmospheres absolute (Ata) pressure for 3 hours. The effects on parasite glucose and aromatic amino acid metabolism were measured in vitro. The effects on the infected host were monitored by physical examination, hematology, and urinalysis. Assays used manometric, colorimetric, gas chromatographic, and high performance liquid chromatography techniques. Trypanosomes isolated from treated hosts consumed an average of 52% more O₂ than those isolated from control infections. This increase was due, in part, to glycerophosphate oxidase activity. Three hours of treatment with OHP were required to see this increase. Concomitantly, glucose consumption was increased, which regardless of treatment was converted largely to pyruvic acid. There was a decrease in aromatic amino acid catabolism. Phenylalanine and tyrosine were cut by about 20%. A decrease of over 60% was seen with tryptophan. Host survival time was increased by an average of 10 hours in animals treated daily with OHP. Pyruvic acid was observed in the urine of treated and control animals at about the same time post infection. The excretion of protein, creatinine, and aromatic amino acid catabolites was delayed in treated animals. The appearance of these metabolic products in the urine appeared to be correlated with parasitemia. Physiological changes occurred as a response to OHP administered to trypanosome-infected mice. The increased oxidative metabolism seen in the parasites suggests that OHP treatment could be beneficial when used in conjunction with chemotherapy directed against the oxidative pathways. Furthermore, the decrease in trypanosome aromatic amino acid catabolism resulting from OHP suggests that such therapy could be used to study the role of the aromatic amino acid catabolites as toxins in host pathogenesis. |
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| Item Description: | Typescript (photocopy). Vita. |
| Physical Description: | xvi, 249 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 242-243). |