Life Sciences Commons^™

The Effect Of Topical Fluorides On The Microleakage Of Sealants, N. Jared Nation

Loma Linda University Electronic Theses, Dissertations & Projects

Purpose: The purpose of this study was to evaluate the possible microleakage found in two groups of sealants; a group bonded with a dentin bonding agent (DBA), and a group bonded without a DBA after exposure to a variety of topical fluorides.

Materials and Methods: Extracted, human molars were placed into 8 groups. Half of the groups contained sealants that were bonded with a DBA and the other remaining groups of sealants were bonded without a DBA. There were two control groups, one that had sealants bonded with a DBA and the other had sealants bonded without a DBA, but …

The Effect Of Naocl, Ca(Oh)2, Mta And Mtad On Root Dentin Fracture Resistance, Sunil Ilapogu

Loma Linda University Electronic Theses, Dissertations & Projects

Various materials are used for the treatment of immature teeth that have been subjected to trauma or decay. It is not well established what effect these materials may have on the immature root dentin. A concern would be the resistance to fracture of the remaining root dentin. The purpose of this study was to compare the resistance of fracture of bovine teeth treated with sodium hypochlorite, calcium hydroxide, gray MTA and gray MTA in conjunction with MTAD after certain periods of time. One hundred and ninety five freshly extracted, intact bovine incisors were prepared using a modified Haapasalo and Orstavik …

P14arf : A P53-Independent Tumor Suppressor, Monte W. Miller

Loma Linda University Electronic Theses, Dissertations & Projects

Many genetic alterations at the CDKN2A locus on human chromosome 9 have been shown to be at least partially responsible for transformation of cells to a cancerous phenotype. This locus encodes two proteins, p16 and p14, that play a pivotal role in tumor surveillance.

Breakdowns in the p14 pathway have been estimated to be present in approximately 40% of human cancers and only recently have its binding partners and effects begun to be defined. Its interaction with the p53 pathway, which is estimated to be inactivated or mutated in 50% of all cancers, makes it difficult to determine its own …

The Potential Role Of Ledgf/P75 In Prostate Cancer, Tracy Ruth Daniels

Loma Linda University Electronic Theses, Dissertations & Projects

The serum autoantibody repertoire from cancer patients is currently being exploited for the identification of tumor associated antigens (TAA) and the design of TAA arrays. Such arrays would facilitate autoantibody profiling and potentially aid in the serological diagnosis and prognosis of tumors. The goal of this study was to identify and characterize prostate-specific TAA. We observed that while the general frequency and titers of autoantibodies in PCa patients were relatively similar to those in matched controls, significant differences could be detected between the two groups in the autoantibody response to the lens epithelial-derived growth factor p75 (LEDGF/p75). LEDGF/p75 is a …

Enterotoxin B Subunit Lectins As Adjuvants For Improvement Of Mucosal Vaccine, Nak-Won Choi

Loma Linda University Electronic Theses, Dissertations & Projects

In comparison with whole organism vaccines, subunit vaccines may be safer for immunization but may lack sufficient immunogenicity to provide complete immunity to the pathogen. To resolve this problem, bacterial and plant enterotoxin B subunit adjuvants containing a variety of receptor-binding properties were used to enhance the immunogenicity of rotavirus subunit vaccines. Enterotoxin B subunit adjuvants were employed to enhance protection against virus infection. Pentameric cholera toxin B subunit (CTB), shiga toxin-1 B subunit (STB) and monomeric ricin toxin B subunit (RTB) molecules were genetically linked to a 90 amino acid peptide from the simian rotavirus (SA11) nonstructural protein NSP4 …

Levels Of Intravenous Enterococcus Faecalis That Cause Heart Colonization, Louis Zane Stromberg

Loma Linda University Electronic Theses, Dissertations & Projects

While previous studies have shown that presence of bacteria in systemic circulation can cause infective endocarditis, there is no information on the specific amount of bacteria necessary to cause this condition. The purpose of this study was to establish the minimum level of circulating bacteria that will cause colonization of damaged heart valves in rats. Fifty-two Sprague-Dawley rats were anesthetized and their heart valves were damaged using an established protocol. A clinical isolate of Enterococcus faecalis was transformed with a plasmid bearing the luxF and Chloramphenicol cassettes to label the bacteria with the light-emitting protein. After four weeks, the rats …

Condylar Remodeling After Distraction Osteogenesis And Bilateral Sagittal Split Osteotomy, Robert Barker Hoffman

Loma Linda University Electronic Theses, Dissertations & Projects

The present pilot study is a histological evaluation of mandibular condyles taken from minipigs that underwent either traditional mandibular advancement (bilateral sagittal split osteotomy), or a distraction osteogenesis procedure to advance the mandible. One pig received a bilateral sagittal split osteotomy with an immediate mandibular advancement of 14 mm, while another pig underwent distraction osteogenesis consisting of a gradual advancement of 2 mm per day to advance the mandible the same distance. The control animal received no surgery.

In the present study, the mandibular condyles of the three pigs (2 control, 2 bilateral sagittal split osteotomy, and 2 distraction osteogenesis) …

Effect Of Caloric Restriction On Bone Mineral Density And Bone Turnover In Over Weight And Obese Individuals With Differing Calcium Intake Levels, Timothy L. Radak

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this multi-center controlled study was to determine the effects of supplemental calcium, dairy products, and dietary calcium on bone metabolism during energy restriction. A total of 107 overweight or mildly obese males and premenopausal females between ages 18-35 years were recruited from the faculty, staff and student populations of each of the four participating institutions (University of Tennessee, Purdue University, Ohio State University and the University of California-Davis). Subjects were randomized to the following outpatient dietary regimens for 12 weeks: Low Calcium (LC) a control diet providing a 500 kcal/day deficit, 0-1 servings of dairy products/day, _ …

Development Of Web Tools For Nlx Simulation Software, Daniel Chai Siriphongs

Loma Linda University Electronic Theses, Dissertations & Projects

Valuable mathematical equations have developed within biology and other sciences (physics, chemistry, etc.) that model various processes, but the complexity of the equations are not easily understood by students, scientists, and those with limited knowledge of the subject area. Simulation software used to visually explain a model is normally proprietary to the specific model equations and cannot be easily adapted to new models by non-programmers. Simulation software needs to be modular and based upon web technologies so that the software can be run on multiple platforms. The NLX simulation software is a group of Java-based objects that can be combined …

Mechanisms Of Oxidative Stress Resistance In Porphyromonas Gingivalis W83, Neal Antonio Johnson

Loma Linda University Electronic Theses, Dissertations & Projects

Porphyromonas gingivalisis one of the most important bacterial etiological agents involved in adult periodontitis. It possesses several virulence factors which aid in its persistence in the periodontal pocket leading to the development of some systemic illnesses. As an anaerobe, P. gingivalismust employ mechanisms to avoid oxidative stress generated by reactive oxygen species during phagocytosis, or the occasional exposure to air. Presently, only three proteins with antioxidant enzymatic function have been identified as playing a role in oxidative stress resistance in P. gingivalis. In this study, attention was focused on the alkyl hydroperoxidase subunit C (ahpC)and bacterioferritin comigratory …

Ionizing Radiation And Endostatin Gene Therapy Against Lung Tumor, Xian Luo

Loma Linda University Electronic Theses, Dissertations & Projects

Although many advances have been made in radiotherapy, tumor radioresistance and normal tissue damage continue to always be important issues for radiation oncologists. Numerous reports have also documented that radiation exposure increases the risk for malignancy and suppresses immune mechanisms. However, increasing evidence has suggested that anti-angiogenic therapy that targets tumor blood supply may alter abnormal tumor vasculature, thus synergizing radiotherapy. The governing hypothesis of the present study was that modification of tumor vasculature by antiangiogenic gene therapy can increase the efficacy of radiotherapy and that radiation can also improve DNA transfection efficiency by increasing expression of the administered gene. …

Regulation Of Ca2+-Activated K+ Channel: Changes With Development, Mike T. Lin

Loma Linda University Electronic Theses, Dissertations & Projects

In ovine middle cerebral arteries, it has been shown that the [Ca²⁺]_i change in response to iberiotoxin, a selective BK channel blocker, is significantly different between adult and fetal VSMCs. Our study of basilar VSMCs in whole-cell preparations showed that the total outward current density of fetal myocytes (57.9 ± 6.7 pA/pF) was greater than that of the adult (37.9 ±1.8 pA/pF). This increase in outward current density is contributed by an increase in BK channel current density in fetal myocytes. Excised, inside-out preparations showed that the unitary conductance, as well as the BK channel expression, did …

Regulatory Mechanisms Of Uterine Artery Contractility : Effect Of Pregnancy, Daliao Xiao

Loma Linda University Electronic Theses, Dissertations & Projects

Regulation of uterine blood flow during pregnancy is important not only for the growth and survival of the fetus but also for cardiovascular well-being of the mother. Pregnancy is associated with a significant decrease in uterine artery vascular tone and a dramatic increase in uterine blood flow. Previous studies have been focused on adaptation of the endothelium to pregnancy and indicated that increased NO sythesis/release plays an important role in vasodilation of the uterine artery in pregnancy. However, little is known about the adaptation of contractile mechanisms of the uterine artery to pregnancy. The central hypothesis of the proposed studies …

The Anti-Proliferation Effects Of Lycopene On Breast Cancer Cells, Tixieanna Dissmore

Loma Linda University Electronic Theses, Dissertations & Projects

Background: The incidence and deaths from breast cancer represent the most cause of all cancer deaths among women. Lycopene, the carotenoid in tomatoes has been associated with decreasing risk of prostate, breast, and digestive tract cancers. Various mechanisms of lycopene action have been proposed, including antioxidant activity and pro-differentiation activities. Identifying changes in the expression of proteins modified by lycopene can provide information to study the modulating effects of lycopene carcinogenesis and tumorigenesis development.

Objective: The objective was to study the anti-proliferative effects of lycopene on MCF- 7 human breast cancer cells and to identify changes in protein expression patterns. …

Bone Formation Using Platelet-Rich Plasma + Allograft: An Experimental Study In Sheep, Edgar Grageda

Loma Linda University Electronic Theses, Dissertations & Projects

Recently Platelet-Rich Plasma has been proven to be an effective regeneration adjunct when combined with autogenous bone in the reconstruction of mandibular defects. However, little is known about the effect of PRP when combined with a bone allograft in the maxillary sinus.

The purpose of this study was to quantitatively evaluate the ability of PRP to enhance bone regeneration in the maxillary sinus of sheep when combined with DFDBA + CCFDBA. Ten sheep were selected for bilateral sinus augmentation DFDBA + CCFDBA + PRP (test) and DFDBA + CCFDBA (control). Five were sacrificed at 3 months and the other five …

Effect Of Anti-Tgfß1 And Pycnogenol® On Scar Formation In Rats, Pilseong Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Wound healing is a complex biologic process that involves chemotaxis and division of cells, neovascularization, synthesis of extracellular matrix proteins, and remodeling of the repaired tissues. Of equal importance is the restoration of normal tissue structure and function without scar formation. The aim of this study was to find out the clinical effects of anti-TGFß1 and Pycnogenol® on scarless wound healing on rat skin.

An acute incision wound model was used with 20 healthy rats. Four incisions were made on each rat's skin and 4 different variables were applied by local infiltration. The four variables were anti-TGFß1, Pycnogenol®, PBS, and …

Relative Validity Of A Food Frequency Questionnaire Used To Assess Food And Nutrient Intake In A Dietary Intervention Study, Gina Segovia Siapco

Loma Linda University Electronic Theses, Dissertations & Projects

Food frequency questionnaire is a cost effective alternative for measuring dietary intake when conducting large scale surveys. We investigated the validity of a 171-item semi-quantitative food frequency questionnaire in assessing food and nutrient intakes and the prescribed intervention measure during a randomized field trial. Eighty-seven free-living adults (48 females and 39 males) aged 30-72 years provided dietary information by self-administering the Walnut Study Dietary Assessment Questionnaire (WSDAQ), which assessed intake over the past six months, and through seven unannounced non-consecutive 24-hour dietary recalls by telephone. Participants were randomly assigned to either a walnut or habitual diet at baseline. For six …

Macrogeographic Genetic Structure In Acanthephyra Curtirostris (Oplophoridae), John Russell Scarbrough

Loma Linda University Electronic Theses, Dissertations & Projects

The vast oceanic living space on our planet is occupied by zooplankton species long assumed to be widespread and genetically undifferentiated across their species range. Recently, however, data from sensitive DNA-based molecular markers has shown that many cryptic species exist in the sea and that marine zooplankton species may be more genetically structured than previously thought. In the oceanic environment, the deep-sea appears to be particularly homogeneous with few observable barriers to gene flow and it is also less studied. DNA-based investigations of genetic diversity in the deep-sea are needed to help determine the spatial scale over which species and …

The Biological Burden Of Antibiotic Resistance In Staphylococcus Aureus, Natasha Samantha Dean

Loma Linda University Electronic Theses, Dissertations & Projects

Antibiotic resistance is a major problem. Resistance is often mediated by genes on bacterial plasmids and dissemination of resistance is commonly achieved by plasmid transfer. The mechanisms of resistance that are presently understood suggest that resistance is energetically costly. If this is generally true, resistance would reduce the fitness of cells in the absence of antibiotics. We examined the hypothesis that resistance reduces the fitness of microorganism and requires continuous selection to be maintained. To test this hypothesis, we measured the effects of plasmid-borne resistance genes on cell growth by comparing the growth rates of Staphylococcus aureus with and without …

Detection Of Bacteria To Dental Tissue By Low-Light Imaging, G-Hong Robert Hsu

Loma Linda University Electronic Theses, Dissertations & Projects

Bacteria have been shown to play an important role in the development of pulp and periradicular disease. The source of the infective bacteria is most often the oral cavity. Previous studies have detected bacteria in teeth that are structurally intact that seemingly have no communication intraorally. Anachoresis has been proposed as a mechanism for localizing circulating bacteria to such teeth. In several previous bacteriologic anachoresis studies, bacteria have been found to localize in inflamed dental tissues. The criticism most commonly associated with these investigations has been the potential contribution of contaminant bacteria resulting in false positive findings.

Low-light image analysis …