Life Sciences Commons^™

Tyrosyl Protein Phosphorylation In Human Bone Cells : Its Potential Role In Mediating Fluoride Induced Osteoblast Proliferation, Alan Blair Thomas

Loma Linda University Electronic Theses, Dissertations & Projects

This dissertation was designed to test the hypothesis that fluoride-stimulated osteoblast proliferation is mediated by specific inhibition of a phosphotyrosyl protein phosphatase, resulting in increased steady state levels of tyrosyl phosphorylation of key cellular proteins. Cellular levels of tyrosyl phosphorylation were determined by an immunoblot detection assay in which cellular proteins were separated by SDS-PAGE, transblotted to nitrocellulose membranes and the phosphotyrosyl proteins were identified by anti-phosphotyrosine monoclonal antibodies. The relative amount of tyrosyl phosphorylation was quantitated by laser densitometric analysis of the autoradiograms. This method showed that fluoride induced dose- and time-dependent changes in the level of tyrosyl phosphorylation …

Effects Of Portuguese Man-Of-War (Physalia Physalis) Venom On Isolated Rabbit Atria, Wayne R. Bonlie

Loma Linda University Electronic Theses, Dissertations & Projects

The cardiac effects of Portuguese man-of-war venom were studied using isolated atria from rabbits. Venom added (7.1 µg protein/ml) to the bath solution stimulates heart rate 120% (P < 0.01) and increases contraction amplitude 308% (P < 0.001). Both effects are dependent on bath concentrations of venom and calcium. The increase in contraction amplitude is significantly attenuated by diltiazem (0.8 µM) and atenolol (10 µM). Atenolol, a β1-adrenergic antagonist, completely blocks the increase in heart rate. Dantrolene (10 µM) did not significantly block the venom's effects. Ryanodine binding increases in the presence of venom showing that the venom is not in competition for calcium channels on the sarcoplasmic reticulum. These results suggest that the venom acts on the sarcolemma to increase calcium permeability, thereby causing an increase in contraction amplitude and possibly causing β1-adrenergic stimulation.

Status, Distribution And Biogeography Of The Birds Of Paraguay, Floyd E. Hayes

Loma Linda University Electronic Theses, Dissertations & Projects

The Paraguay River divides the Republic of Paraguay into two distinct regions: the Chaco to the west and the Orient to the east. The relatively flat Chaco is characterized by thorn scrub forests in the west, sub humid forests in the northeast and palm savannas in the southeast. The topographically diverse Orient is characterized by campos cerrados in the northeast, savannas in the west and southwest, and humid forests elsewhere. Paraguay's climate is subtropical, with rainfall increasing roughly fourfold from west to east.

Previous studies of the birds of Paraguay have focused primarily on the distribution and taxonomy of resident …

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. …

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 …

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 …

Factors Affecting Behavioral Variation Of Individual Glaucous-Winged Gulls (Larus Glaucescens) While On Territory, Michael Murdoch

Loma Linda University Electronic Theses, Dissertations & Projects

Factors affecting the patterns of behavior of individual Glaucous-winged Gulls (Larus glaucescens) on Protection Island, Jefferson County, Washington were examined. Males were found to be present on territory often than females. Proportions of behavior varied by time of season. Gulls tended to be more alert (used upright and intermediate-upright displays) during the "chick" stage than earlier in the season. Attendance rates were very similar between individuals of the same gender, and a significant correlation was found between the attendance rates of members of a pair. However, sequences of territorial behavior varied significantly between genders.

Modelling Avian Distributions Of The Navarrese Region In Northern Spain With A Geographic Information System, Samuel Soret-Garcia

Loma Linda University Electronic Theses, Dissertations & Projects

GIS (Geographic information Systems) technology was used for identifying relations between environmental characteristics and the breeding distributions of nine avian species of the Navarrese region in northern Spain. Data overlays of multiple GIS layers derived the explanatory variables for modelling the breeding distributions from logistic regressions. A spatial autocorrelation analysis was conducted to characterize the distribution patterns and to incorporate spatial factors (neighborhood effects) into their analysis.

All nine patterns analyzed exhibited a high level of spatial autocorrelation. Accordingly, the basic hypothesis of spatial randomness was rejected in favor of spatial clustering for the sample data. The breeding distributions strongly …

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 …