AbstractMEASUREMENT OF FORCES AND MOMENTS IN THREE-DIMENSIONAL ARCHWIRESBy Dwight V. Buelow, D.D.S.A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University.Virginia Commonwealth University, 2003Major Director: Steven J. Lindauer, D.M.D., M.D.Sc.Chairman and Professor, Department of OrthodonticsOrthodontic tooth movement occurs in response to the application of controlled mechanical force systems. The purpose of this study was to improve understanding of those force systems by evaluating differences between the resultants of two-dimensional and three-dimensional orthodontic appliance activations. An in-vitro model was constructed and three force-moment gauges were used to measure the forces and moments produced. Comparisons were made between two-dimensional and three-dimensional v-bend activations. Measurements were made with both edgewise and ribbonwise wire orientations. Locations of v-bends resulting in zero moment at the incisor were found to be closer to the molar than the anticipated 1/3 of the distance from molar to incisor, for both two-dimensional and three-dimensional wires. For two-dimensional wires, this v-bend location was found to be approximately ¼, while for three-dimensional wires it was even closer to the molar. Ribbonwise wires, both two-dimensional and three-dimensional, produced forces and moments of greater magnitude than their edgewise counterparts. Further research is required to explain the differences between anticipated and actual results, and to develop more accurate means of modeling orthodontic force systems.

Understanding mast cell development is central to allergic disease pathophysiology. Our laboratory has previously shown that cytokines such as IL-4 and IL-10 inhibit mast cell development from bone marrow progenitors. These studies encouraged our interest in other regulatory cytokines, including transforming growth factor β1 (TGF- β1). TGF- β1 has many cellular sources, one of which is CD4+CD25 regulatory T cells (Tregs). We wanted to determine the effects of Transforming Growth Factor (TGF) βl on mast cell development. We find that TGFβl decreased FcεRI, c-Kit, T1/ST2 and FcεR expression, and inhibited granule formation in developing mast cells. Accessory cells were not required for this inhibition. Smad3-deficiency did not alter the response of bone marrow cells to TGFβ1. TGFβl inhibited expression of the FcεRI a subunit protein, without decreasing β or γ proteins. Mast cells derived in the presence of TGFβl were functionally impaired, as IgE-mediated cytokine secretion was greatly reduced. The changes in granule formation and surface antigen expression were long-standing, as they were not reversed by transfer to W/WV mice. The TGF-β1 dependent transcriptional regulation of bone marrow cells from which mast cells develop was examined through DNA microarray analysis. Wild type (WT) bone marrow cells were stimulated with IL-3+SCF+vehicle or IL-3+SCF+TGF-βI for 10 days and their transcriptomes* analyzed. The results identified which components of transcriptional regulation were regulated by TGF- β1. Of particular interest was the upregulation of the β subunit of the FcεRI, inspite of no receptor surface expression and the differential regulation of various mast cell proteases (MCPs). This initial survey provides a potential starting point for further analysis of the role of TGF-β1 -dependent signaling in developing mast cells. Because they produce TGF-β1 and/or IL-10, regulatory T cell-dependent murine mast cell inhibition was examined. Co-culture of mast cells with regulatory T cells for 6 days downregulated mast cell number, high affinity IgE receptor and c-Kit surface expression. This led to a decrease in TNFa release making mast cells functionally impaired. By using Tregs from IL-10 KO mice, this effect was proven to be IL-10 dependent. Mast cells are mediators of inflammatory disease. TGFβl and IL-10 may contribute to mast cell homeostasis by inhibiting maturation from bone marrow precursors. The effects of TGFβ1 and regulatory T cell derived IL-10 result in greatly diminished expression of cell surface markers, reduced granulation, and lack of responsiveness to IgE-mediated activation. Thus TGFβl and/or CD+CD25+ T cells can serve as potent and multifunctional regulators of mast cell maturation and/or function.* A set of genes that are expressed in a cell at any given time.

Problem: The United States of America has one of the highest number of HIV infections in the world; approximately 1.3 million people in North America were living with HIV in 2007. Factors influencing HIV survival are essential to disease management and care. Research findings suggest religion and spirituality may be essential components to health and well-being in individuals with HIV-Disease. Purpose: This study was designed to determine how well spirituality predicted health status in a convenience sample of 39 adults diagnosed with HIV-Disease. Procedure: A model building approach was used to explore relationships among the five variables of the Neuman Systems model. The following were used to collect data: (physiological) 1993 Revised CDC Classification System for HIV Infection, Revised HIV Center Medical Staging Scale (rHMCSS), lowest ever CD4+T-lymphocyte count, current CD4+T-lymphocyte count, AIDS status, and viral load; (spiritual) Spiritual Well-Being Scale (SWBS), Brief Religious Coping Scale (RCOPE), Religious Commitment Index—10, and religious affiliation; (psychological) Sense of Coherence—13 Scale (SOC) and mental health history; (sociocultural) ethnicity, income, and relationship status; (developmental) date of birth.Results: Income, the Meaningfulness subscale of the SOC-13 scale, age, and the Existential Well-Being subscale of the SWBS had significant relationships with the current rHCMSS score and explained 28.3% (p = .027) of the variance. The model that included EWB, Negative RCOPE, and the interaction of Negative RCOPE and EWB, in which an adjustment for income had been made, explained 32.9% (p = .011) of the variance in health status.Conclusions: The five variables of the NSM provided a well supported, holistic framework for investigating how much spirituality contributed to health status in PLWHA. The best explanatory model included: EWB, Negative RCOPE, income, and the interaction between EWB and Negative RCOPE. The existential component of spirituality, and especially the element of meaning, modified by negative religious coping, is an essential contributor to the health status of people living with HIV-Disease.Software: This document was created in Microsoft Word 2000. Power analysis was done using nQuery 6.0 Software and SPSS 15.0 © Statistical Software program was used for other statistical analyses.

The visual system is one of the most widely used and best understood sensory systems and the dorsal lateral geniculate nucleus (dLGN) of the mouse has emerged as a model for investigating the cellular and molecular mechanisms underlying the development and activity-dependent refinement of sensory connections. Thalamic organization is highly conserved throughout species and the dLGN of the mouse possesses many features common to higher mammals, such as carnivores and primates. Two general classes of neuron are present within the dLGN, thalamocortical relay cells and interneurons, both of which receive direct retinal input. Axons of relay cells exit dLGN and convey visual information to layer IV of cortex, whereas interneurons are involved in local circuitry. In addition, dLGN receives rich nonretinal input from numerous areas of the brain. Studies thus far have focused on the retinogeniculate pathway and the development of connections between retinal ganglion cells (RGCs) and relay cells has been well characterized. However, there are still a number of unanswered questions about circuit development in dLGN. Here we examined two aspects that are not well understood, the pattern of retinal convergence onto interneurons and the structural and functional innervation of nonretinal projections. To address the first issue we conducted in vitro whole-cell recordings from acute thalamic slices of GAD67-GFP mice, a transgenic strain in which dLGN interneurons express GFP. We also did 3-D reconstructions of biocytin-labeled interneurons using multi-photon laser scanning microscopy in conjunction with anterograde labeling of retinogeniculate projections to examine the distribution of retinal contacts. To begin to examine the development of nonretinal connections in dLGN we made use of a transgenic mouse (golli-τ-GFP) to visualize corticogeniculate projections, one of the largest sources of nonretinal input to dLGN. Using this mouse we studied the timing and patterning of corticogeniculate innervation in relation to the development of the retinogeniculate pathway. We also used binocular enucleation and genetic deafferentation to test whether the retina plays a role in regulating nonretinal innervation. We found that there is a coordination of retinal and nonretinal innervation in dLGN. Projections from the retina were the first to innervate and they entered dLGN at perinatal ages. They also made functional connections with both relay cells and interneurons at early postnatal ages. Interestingly, relay cells underwent a period of retinogeniculate refinement, whereas the degree of retinal convergence onto interneurons was maintained. This possibly reflects the different roles that these two cell types have in dLGN. Both structural and functional corticogeniculate innervation was delayed in comparison and occurred postnatally, however in the absence of retinal input the timing of corticogeniculate innervation was accelerated. RGCs transmit the visual information encoded in the retina to dLGN so it may be necessary for these connections to be formed before those from nonretinal projections, which serve to modulate that signal on its way to cortex. Thus precise timing of retinal and nonretinal innervation may be important for the appropriate formation of connections in the visual system and the retina seems to be playing an important role in regulating this timing.

In these studies we sought to determine the role of Fyn kinase and ADAM10 in B cell biology. A disintegrin and metalloproteinase 10 (ADAM10) is a zinc dependent proteinase related to matrix metalloproteinases. ADAM10 has emerged as a key regulator of cellular processes by cleaving and shedding extracellular domains of multiple transmembrane receptors and ligands. In particular, ADAM10 has been identified as a key regulator of lymphocyte development. Here we report that ADAM10 is dispensable for early B cell development within the bone marrow. However, deletion of ADAM10 from all peripheral B cells or in post-switch cells leads to severe impairments in humoral responses. When ADAM10 was deleted from all peripheral B cells a decrease in antigen specific IgG production was seen both with respect to serum levels and IgG ASCs, indicating that plasma cell (PC) differentiation is influenced. Cells producing high affinity antigen specific antibodies were particularly affected, consistent with defects in germinal center (GC) reactions. Moreover, changes in lymphoid architecture were also observed. Consistent with these findings, follicular dendritic cell (FDC)-reticula was undetectable following immunization. On the other hand, when ADAM10 was deleted in post-switch B cells, GC formation and lymphoid architecture were not impaired. Despite normal architecture, however, antibody production was still affected, likely due to abnormal gene expression in ADAM10-deficient PCs. Consistent with this hypothesis, PCs isolated from ADAM10Δ/ΔIgG1-cre+/- showed decreased expression of genes that facilitate plasma cell differentiation and function and increased expression of Bcl6, an inhibitor of PC differentiation. Fyn kinase is a member of the Src protein tyrosine kinase. Fyn is widely expressed in many cell types, including lymphocytes. Fyn has been shown to interact with both the B cell and T cell receptor (BCR and TCR, respectively). While Fyn-deletion did not impair the development of immature T cells and B cells, TCR signaling was altered in mature T cells. Our results demonstrate that Fyn-KO mice have significantly low basal levels of IgG1 and IgG2a. Additionally, these mice displayed delayed kinetics in the production of NP-specific IgG1 and IgG2b, and significantly low NP-specific IgG2a after a T-dependent immunization protocol. Defects in antibody production correlated with significantly reduced numbers of GC B cells, TFH cells and splenic PCs. Moreover, Fyn-KO B cells showed decreased production antibody following in vitro activation. Our results thus demonstrate that Fyn-mediated signaling and B cell ADAM10 expression are necessary for optimal humoral responses.

Thrombosis is one of the leading causes of mortality and morbidity that is associated with myocardial infarction, stroke and pulmonary embolism. Anti-thrombotic agents which intend to reduce the occurrence and severity of thrombosis usually target the enzymes of the coagulation cascade. FXIa, a 160 kDa homodimer is gaining popularity of late as a potential target for anti-thrombotic agents due to its relative safety. A number of inhibitors which target the active site of FXIa have been reported but to our knowledge there have been no inhibitors which act via an allosteric mechanism. The aim of this project was to screen for allosteric inhibitors of FXIa from of pool of sulfated small-molecules.These molecules were primarily designed to act as heparin mimetics; heparin being a natural anti-coagulant. These compounds were then analyzed to determine whether inhibition was via an allosteric mechanism.

Purpose: Obesity/Overweight in children is an epidemic and the most common disorder of childhood in the developed world. Prevalence is increasing, leading to short- and long-term complications. Breastfeeding may protect against childhood obesity, but the debate is ongoing. The main purpose of this project was to assess the relationship between breastfeeding and being overweight in early childhood.Methods: Data were collected from the State and Local Area Integrated Telephone survey; National Survey of Children's Health, 2003. Overall, 16,358 children, ages 3 to 5, were included in the sample. SPSS Complex Sample software was utilized to generate for all analyses. Complex samples crosstabs was utilized to see if there is association between the outcome and risk factors. Complex samples logistic regression was done to assess whether breastfeeding is associated with being overweight in childhood after adjustment for potential confounders.Results: Being overweight was more prevalent among children who are Black, living at 95th percentile). After adjusting for confounders, the effect remained statistically significant (OR: 1.6; 95% confidence interval: 1.2-2.1).Conclusions: Breastfeeding has a protective effect against being overweight in children 3 to 5 years of age. While more research is needed to investigate the risk factors for overweight, public health efforts should continue to promote breastfeeding as a safe and effective method for nutrition, which has the potential to improve the overall health of children.

Purpose: The purpose of this study was to determine the relationship of CYP2B6 genotype to the clinical response to meperidine in pediatric dental patients. Methods: Twenty-five patients, ASA I/ II, 45–92 months old, received an oral sedative regimen containing meperidine for dental treatment. The North Carolina Behavior Rating Scale (NCBRS) and Overall Effectiveness of Sedation Scale (OESS) were used to assess their behavior and sedation outcome. Saliva DNA samples were genotyped by PCR-RFLP. Results: We found the following genotype distributions: homozygous wild-type 1*1 (n = 8, 32%), heterozygous 1*6 (n = 13, 52%), and homozygous variant 6*6 (n = 4, 16%). The genotypes were predictive of a significant decrease in the overall effectiveness of sedation. Conclusion: Variation in CYP2B6 appears to be predictive of less successful sedations; wild-type individuals experienced more successful sedations than the homozygous variant 6*6. Future research regarding the enzyme kinetics of meperidine is needed to determine the exact enzymatic function of CYP2B6 and its variants.

White spot lesions (WSLs) or decalcifications remain a common complication in orthodontic patients with poor oral hygiene. The purpose of this study was to compare attitudes regarding the development of WSLs among patients, parents, orthodontists and general dentists and improve prevention and treatment protocols through better communication. A survey was developed to evaluate and compare the current opinions of orthodontic patients (n=315), parents (n=279), orthodontists (n=305) and general dentists (n=191) regarding the significance, prevention and treatment of WSLs. All four groups indicated that WSLs did detract from the overall appearance of straight teeth. All four groups indicated that patients were the most responsible for the prevention of WSLs. All four groups indicated that the general dentist should be more responsible for the treatment of WSLs than the orthodontist. General dentists were significantly more likely to indicate that the orthodontist was most responsible for the prevention of WSLs (P <0.005).

Objective: 2009 H1N1 influenza was first detected in the Northern Hemisphere in April 2009. National data have suggested that the novel influenza virus disproportionately causes severe illness in children and young adults, a somewhat different presentation from traditional seasonal flu which normally strikes hardest in the very young and older adults. This may or may not be the case in Virginia, which, if it is different, may suggest a need to alter flu prevention messages and vaccine policy as the outbreak continues through the fall 2009-10 influenza season. This report examined the early presentation of the new influenza virus in Virginia, compared with the seasonal flu presentation. Methods: Surveillance data of influenza-like illness (ILI) visits to hospital emergency departments and urgent care centers for the period Oct. 2008 to Aug. 2009 were obtained from the Virginia Department of Health. The period from Oct. 2008-March 2009 was considered to be the normal flu season, while April-Aug. 2009 was considered as the 2009 (novel) H1N1 flu season. Descriptive statistics looked for differences by age, region and sex with respect to the proportion of visits that were for influenza-like illness compared to all reported illness for the normal and H1N1 flu seasons. Chi square and p-values were used to assess the level and significance of differences between flu seasons. Results: While the 2009 H1N1 influenza was a novel virus that, like all influenza viruses, could mutate and change into a form causing more severe illness, during the early months of the epidemic/pandemic, the virus did not appear to cause more illness as a percent of all illness compared to the preceding months of influenza in Virginia. Though it was unexpected to have influenza-like illness in the amount seen during April-August 2009, with several exceptions the level of flu-like illness compared to all illness was not higher than during the normal flu season immediately preceding the appearance of the 2009 H1N1 influenza. Conclusion: During the early months of the novel influenza H1N1 epidemic/pandemic in Virginia, the novel influenza virus caused levels of illness that were lower than levels of illness seen during the preceding normal flu season. Further study that examines the novel influenza virus through the end of the 2009-10 season may help to quantify the impact of the new virus. Flu-like illness reports spiked, for instance, as schools and colleges returned for fall 2009 semesters.