Medicine and Health Sciences Commons^™

Aerotaxis In Bacillus Subtilis, Laurence Samuel Wong

Loma Linda University Electronic Theses, Dissertations & Projects

B. subtilis, like Escherichia coli and Salmonella typhimurium, responded to a step increase in oxygen concentration by swimming smoothly (~ 35 s duration) and to a decrease in oxygen by tumbling. In a spatial gradient of oxygen in liquid media, a band of cells congregated near the air interface. Aerotaxis required a functioning respiratory chain. Adaptation of B. subtilis, E. coli and S. typhimurium to media containing amino acids requires methylation of receptors/methyl-accepting chemotaxis proteins. Adaptation to oxygen and phosphotransferase sugar substrates in B. subtilis was dependent on methylation, unlike similar adaptation in E. coli and S. typhimurium. …

A Non-Human Primate Model For Evaluating A Fenestration Corticotomy Technique, Philip G. M. Khng

Loma Linda University Electronic Theses, Dissertations & Projects

A study model has been designed to evaluate the effectiveness of a new fenestration corticotomy procedure in two non-human primates Macaca fasicularis.

The objective of this study was to evaluate the efficacy of a new conservative corticotomy procedure to facilitate dental translation using fenestrations. This pilot study compared treatment and control quadrants of each individual animal's maxilla and mandible with both having the same retraction appliance and force on the 2nd premolar following extraction of the 1st molars. The null hypothesis stated that there was no significant statistical difference between the new conservative corticotomy procedure (fenestrations) when compared with …

Suppressive Effects Of Transforming Factor-Β And Interleukin-10 On The Cytolytic Activity Of Murine Macrophages And Reversal By Cytokines, Chin-Hung Lin

Loma Linda University Electronic Theses, Dissertations & Projects

In this study, the suppressive effects of transforming growth factor-β (TGF-β) and interleukin-10 (IL-10) on peritoneal macrophage killing of H238 target cells and the potential for reversal of the immunosuppressive effect by IL-4 and interferon-γ (IFN-γ) were investigated. The responsiveness of naive and peptone-activated macrophages was compared. The cytolytic activity for tumor cells of these effector cells was measured by percent lysis of ³H-thymidine labeled Herpes simplex virus type 2-transformed tumor cells (H238). After 18-24 hours of incubation with TGF-β or IL-10, the cytolytic activity of macro-medium alone. The immunosuppressive effect of TGF-β or IL-10 on non-activated macrophages was …

Thymic Peptide Modulates Glutathione Redox Cycle And Antioxidant Enzymes In Macrophages, Choon Sil Park

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of a 6-kDa thymic peptide (TP) on the oxidative burst of a murine macrophage cell line J774 was determined. TP (12.5-200 μg/ml) was incubated with 5 x 10⁵ J774 cells at 37° C and 5% C0₂ for 18 h and oxidative burst was triggered by zymosan; chemiluminescence was amplified by luminol and measured in an automated luminometer. TP exhibited a concentration-dependent inhibition of oxidative burst. To study the mechanisms involved in TP’s inhibition of oxidative burst, its effect on the glutathione (GSH) redox cycle, GSH biosynthesis, and antioxidant enzymes was investigated. TP was shown to increase …