Thesis (MSD) --Boston University, Henry M. Goldman School of Dental Medicine, 2014 (Department of Orthodontics and Dentofacial Orthopedics). / Includes bibliographic references: leaves 38-40. / Background: Previous CBCT studies have established standards for mesiodistal angulations and faciolingual inclinations of the dentition in a non-Caucasian population. These standards help ensure proper root positioning, since they are not based solely on the clinical crowns. Objective: to use the USC root vector analysis to measure the tip and torque of teeth to establish Caucasian norms. Methods: We measured and obtained mean mesiodistal and faciolingual angulations from each whole tooth from 34 pretreatment and 43 previously treated Caucasian patients, by using the University of Southern California root vector analysis program in Dolphin 3D. We used descriptive statistics to present normal torque and tip values. Two-Sample t-test was executed to compare right tip and torque values to the left side. One sample t-test was used to compare our Caucasian sample to the multi-ethnic sample in Tong et al. paper, and to compare pretreatment to post-treatment patients within the Caucasian group. Results: Comparing right to the left tip and torque values in our sample showed no significant difference (P[greater than]0.05). We compared our study sample to the USC sample norm and we found that there was statistical significant difference in almost all tip and torque values (P[less than]0.05). We found no statistically significant difference in angulation of teeth between treated and untreated Caucasian patients. Conclusion: We measured and obtained mean mesiodistal and faciolingual angulations from each whole tooth from 34 pretreatment and 43 previously treated Caucasian patients′ by using the University of Southem California root vector analysis program in Dolphin 3D. When comparing the right side to the left side of the treated and untreated Caucasian groups, there was no statistically significant difference between the measurements for either tip or torque. We found a statistically significant difference in angulation of teeth between Caucasian and USC populations. We found no statistically significant difference in angulation of teeth between treated and untreated Caucasian patients.

PURPOSE: African Americans (AA) are at a higher risk of colorectal cancer (CRC) and some studies report a higher frequency of microsatellite instability (MSI) in this population while others report lower frequency compared to Caucasians. AIM: To determine and evaluate the association of race and clinical factors with MSI frequency through meta-analysis. METHODS: Twenty-two studies out of 15,105 (1997-2015) were evaluated after a search in different literature databases, using keywords "colorectal cancer, microsatellite instability, African Americans, Caucasians and Hispanics". We used random effect meta-analysis to calculate the MSI frequency in all studies as well as in African American and Caucasian samples. Meta-regression analysis was used to assess the univariate effect of race, gender, age, tumor location and stage on MSI frequency. RESULTS: The overall MSI frequency among CRCs was 17% (95% CI: 15%-19%, I-2 = 91%). In studies with available race data, The MSI rate among AAs, Hispanics and Caucasians were 12%, 12% and 14% respectively and was not significantly different. Sub-group analysis of studies with racial information indicates MSI OR of 0.78 for AAs compared to Caucasians. CONCLUSION: CRCs demonstrate an overall MSI frequency of 17%. MSI frequency differences between AAs and Caucasians were not pronounced, suggesting that other factors contribute to the racial disparity. The methodological approaches and biological sources of the variation seen in MSI frequency between different studies need to be further investigated.

Question: Can passive static stretching lower blood glucose in an at-risk population? Design: Randomised, within-participant experimental study. Participants: 22 adults (17 males) either at increased risk of Type 2 diabetes or with Type 2 diabetes. Intervention: The participants reported to the laboratory 2. hr after eating a meal, and drank 355. ml of fruit juice (∼43. g carbohydrate). Thirty minutes later, they underwent either a 40. min passive static stretching regimen or a mock passive stretching regimen. Stretching consisted of six lower body and four upper body static passive stretches. For the mock stretches, the same positions were adopted, but no tension was applied to the musculature. Outcome measures: Blood glucose levels for both the stretching and mock stretching were analysed from a finger prick sample using a hand-held glucometer. Values were obtained at baseline (0. min), during the regimen (20. min), and after the regimen (40. min) on both study days. Results: Compared to mock stretch, stretching resulted in a significantly greater drop in blood glucose at 20. min (mean difference 28. mg/dL, 95% CI 13 to 43; or 1.57. mmol/L, 95% CI 0.72 to 2.39). This effect was also statistically significant at 40. min (mean difference 24. mg/dL, 95% CI 9 to 39; or 1.35. mmol/L, 95% CI 0.50 to 2.17). Conclusion: These results suggest that passive static stretching of the skeletal muscles may be an alternative to exercise to help lower blood glucose levels.

Blacks are more affected by Human Immunodeficiency Virus (HIV)/Acquired Immunodeficiency Syndrome (AIDS) than any other race or ethnicity in the United States. The purpose of this dissertation was to investigate potential race-based differences in cardiovascular disease (CVD)-related hospitalizations and use of opportunistic infection (OI) prophylaxis between Blacks and Whites with HIV/AIDS. This dissertation includes two systematic literature reviews that identified knowledge gaps in the areas of CVD diagnosis and OI prophylaxis use between Blacks and Whites with HIV/AIDS, as well as two independent studies that addressed some of the gaps identified in the literature. The first study evaluated the association between race and CVD-related hospitalization in Blacks and Whites with HIV/AIDS. Data were retrieved from the 1996-2008 National Hospital Discharge Surveys (NHDS). Approximately 1.5 million hospital discharges were identified. After controlling for confounders, the odds of CVD-related hospitalization were 45% higher for Blacks than Whites (OR=1.45, 95% CI, 1.39-1.51). There was a statistically significant difference in the proportions of CVD-related hospitalization type and race (x2=479.77; df=3; p<0.001). Compared to Whites with HIV/AIDS, Blacks with HIV/AIDS had greater proportions of heart failure and hypertension, but lower proportions of stroke and coronary heart disease. These results suggest that there is an influence of race on both the occurrence and type of CVD-related hospitalizations in patients with HIV/AIDS. The second study assessed if race was associated with the use of OI prophylaxis (Pneumocystis jiroveci pneumonia [PCP] and Mycobacterium avium complex [MAC]). Data for this study were retrieved from the 1996-2008 National Hospital Ambulatory Medical Care Surveys (NHAMCS). Approximately 9.1 million hospital ambulatory visits were identified. After controlling for confounders, the odds of PCP prophylaxis use were 16% higher for Blacks than for Whites (OR=1.16, 95% CI, 1.15-1.17). In a separate regression analysis, the odds of MAC prophylaxis use were 12% higher for Blacks than for Whites (OR=1.12, 95% CI, 1.10-1.13). These findings suggest that Blacks with HIV/AIDS may have increased odds for OI prophylaxis. Based on this work, there is a need for further research to confirm these findings and to identify the causes of these race-based disparities. / text

Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2009.

Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2009.

The overall aim of the study is to investigate how a social and collective memory is mobilized by the directors’ depiction of ethnicity and gender roles from a post- colonial and gender perspective. The thesis focuses on how ethnicity and gender roles are depicted in each movie and how this results in a mobilization of a social and collective memory. The results show that Django Unchained mobilizes a memory by its use of the invective nigger and iconic acts of slavery, such as whipping and cotton picking. From a gender perspective, the results show that men worked with jobs that required more strength, compared to the jobs of women and thus mobilizes a memory of how we remember the gender roles of slaves. Nevertheless, these memories can result in traumas and to recover from them, memories must be revisited. Similarly, yet differently, the results show that 12 Years a Slave mobilizes a memory by its use of the invective nigger and by the use of songs that solidified the hierarchy present during slavery. In other words, these songs were used to exhibit the level of supremacy Caucasians possessed from a post-colonial perspective. The conclusion drawn in the study is that 12 Years a Slave, as a historical source, provides audiences with considerably more authenticity compared to Django Unchained. Therefore an individual might feel as if he or she has lived the life of Solomon Northup and experienced and endured everything he did.

The human forkhead box O1A (FOXO1A) gene on chromosome 13q14.1 is a key transcription factor in insulin signaling in liver and adipose tissue and plays a central role in the regulation of key pancreatic β-cell genes including IPF1. We hypothesized that sequence variants of FOXO1A contribute to the observed defects in hepatic and peripheral insulin action and altered β-cell compensation that characterize type 2 diabetes (T2DM). To test this hypothesis, we screened the three exons, 3′ untranslated region, and 5′ flanking region for sequence variants in Caucasian and African-American individuals with early onset (<45 years) T2DM. We identified only six variants; none altered the coding sequence, and except for one variant in the 3′ untranslated region, they were rare or absent in Caucasians. To increase coverage of the gene, we selected seven additional variants in the large first intron and 5′ flanking region, thus providing 13 variants that spanned 116.4 kb. Based on frequency and linkage disequilibrium patterns in a subset of individuals, we selected eight SNPs to type in a Caucasian population comprising 192 unrelated nondiabetic control individuals and 192 individuals with T2DM, and 10 SNPs to type in 182 controls and 352 diabetic individuals of African-American ancestry. No variant was associated with T2DM (African-Americans, p > 0.08; Caucasians, p > 0.09). Of the 8 Caucasian SNPs, six comprised a single haplotype block spanning over 100 kb and including most of the large first intron. In contrast, no block was observed among SNPs typed in African-Americans. No haplotype was associated with T2DM. FOXO1A variation is rare and is unlikely to contribute to T2DM in either Caucasian or African-American populations.

The objective of this thesis was to investigate intersectional (categorical/social) invisibility and the extent to which this phenomenon occurs in a comparison of dominant (i.e., Caucasian), and non-dominant (African-American and Latino) social/ethnic groups. It has been found that intersectional invisibility occurs among African-American women with respect to Caucasian men and women, and African American men (Sesko & Biernat, 2010), but little of this research has been done regarding Latinas. Thus, this experiment aims to not only examine whether Latinas are also subject to intersectional invisibility among dominant (i.e., Caucasian) and non-dominant (i.e., African American and/or Latino) groups, but to determine whether the theory can be extended to perceptions between non-dominant groups such as African-Americans and Latinos. Determining whether intersectional invisibility occurs among Latinas, moreover, may provide theoretical and practical insights of what advantages/disadvantages Latinas may particularly endure as members of the rapidly growing Latino population in the U.S.

Background: Type 2 diabetes affects approximately 8% of the world’s population. Individuals of South Asian ancestry tend to develop metabolic abnormalities, leading to diabetes, at lower measures of absolute obesity and approximately 10 years earlier than white Caucasians. Current literature is unclear on the source of this ethnic heterogeneity; the variation in risk cannot be explained by lifestyle factors alone. The overarching aim of this thesis is to explore the role of genetic variants and epigenetic differences to explain the greater risk for type 2 diabetes among South Asians. Methods: We first conducted a systematic review of the literature to ascertain the genetic risk from known single nucleotide polymorphisms (SNPs) among South Asians. We then compared these risk estimates to those from white Caucasians in a cohort of 69,033 individuals. Second, using the EpiDREAM prospective cohort study of individuals at high-risk for diabetes, we assessed the impact of genetic burden for impaired pancreatic beta-cell function alone and together with abdominal obesity on glucose traits. Ethnic heterogeneity in this interaction was also studied. Lastly, using data from two Canadian birth cohorts of South Asian and white Caucasian ancestry, we investigated ethnic differences in the epigenetic architecture for genes known to be implicated birth weight and length, as both are associated with the future risk of adult diabetes. Results: The systematic review identified 15 SNPs robustly associated with type 2 diabetes in both South Asians and white Caucasians. The magnitude of risk and allele frequency of these genetic variants did not differ between the ethnic groups. Additionally, we identified 8 novel polymorphisms implicated in diabetes only among South Asians. Second, using data from the EpiDREAM study, we identified an interaction between cumulative genetic burden of beta-cell impairment, measured using an un-weighted genotype score, and abdominal obesity on glucose traits in South Asians, but not white Caucasians. Third, our investigation of differential DNA methylation between the ethnic groups revealed seven CpG sites for which changes in methylation corresponded to alterations in birth weight among white Caucasians, but not South Asians. An independent agnostic genome-wide search identified methylation levels at three CpG sites that appear to uniquely modulate birth weight in South Asians. Conclusions: Overall, our results indicate that the greater risk for metabolic traits in South Asians likely does not result from common genetic variants shared by both South Asians and white Caucasians. Rather, differences in risk may be additionally influenced by unique risk variants in South Asians. Furthermore, it appears that the risk from a genetic impairment in South Asians may be magnified by abdominal obesity. / Thesis / Doctor of Philosophy (PhD)