Cameron County Research Articles

Using Social Network Analysis to Identify Influential Community Organizations

BackgroundWe used a social network approach to identify influential community organizations within integrated public health networks in three regions in Texas, US: Houston/Harris County, Cameron County, and Northeast Texas. The study aimed to understand how network structures influence organizational performance in COVID-19 response. MethodsIn collaboration with community partners in each region, we administered a snowball sampling network data collection. Initial seed sets for the regions of 23, 25, and 55 organizations identified other organizations that then responded to the survey, which expanded the sets to 268, 145, and 138, respectively. Principal component analysis (PCA) identified key network structures—centrality and brokerage—and we introduced two network-based performance measures: Fulfillment Rate (FR), which measures securing needed resources, and Provision Rate (PR), which measures providing resources to others. We tested hypotheses to examine the associations between these network structures and organizational performance. FindingsCentrality consistently emerged as a predictor of organizational performance across all three regions. Community organizations that are more centrally positioned, rather than broker organizations, play a critical role in meeting resource needs and providing services to other organizations. Centrally positioned organizations conducted more COVID-19 tests, whereas brokers administered fewer vaccines. InterpretationsThis study suggests that public health interventions should prioritize central organizations for resource allocation and distribution. Our network-based performance metrics offer new avenues for evaluating organizational effectiveness in networked public health systems, with broader applicability to future crises and public health planning.

A multivariate approach to assessing landscape structure effects on wildlife crossing structure use

BackgroundComplexity in landscape structure is often assessed using individual metrics related to ecological processes. However, this rarely incorporates important relationships among metrics and may miss landscape structure effects. Multivariate statistics provide techniques for assessing overall landscape structure effects. We assessed how multivariate statistics could be used to connect landscape structure with an ecological process [bobcat (Lynx rufus) wildlife crossing structure (WCS) use]. We tested how landscape structure at WCS sites compared to the surrounding landscape and how structure affected detections at WCS sites. Our study was conducted in Cameron County, Texas, USA where WCSs are in various stages of construction and monitoring. We used a classified land use/land cover map and aerial LiDAR to calculate configuration and density metrics at WCS and random sites. We created indices for configuration and density using principal components analysis to assess landscape structure effects on camera trap detections at WCSs.ResultsLandscape structure at WCSs did not differ from random locations. Wildlife crossing structure use increased with greater woody cover and decreased with increasing vegetation density. Our indices allowed identification of differences in how configuration and density impacted WCS use. Ordination methods helped identify individual contributions of landscape metrics to the overall landscape structure effect.ConclusionsWildlife crossing structures are permanent fixtures on landscapes, so selecting appropriate locations using broad-scale landscape structure likely increases target species use. Using indices of landscape structure provides planners with a more holistic approach to WCS placement and provides a more comprehensive picture of landscape pattern and process relationships.

Review of the life history and conservation of federally endangered plant species of the Lower Rio Grande Valley, Texas, U.S.A.

This review aims to summarize information critical to the conservation of the federally listed endangered species of South Texas, which occur along the border of Texas and Mexico. This paper describes the characteristics, habitat, population status, distribution, life history, threats, and restoration of endangered plant species of the Lower Rio Grande Valley, Texas, which includes Cameron, Willacy, Hildago, and Starr County. Seven federally listed species are considered including Ambrosia cheiranthifolia, Asclepias prostrata, Astrophytum asterias, Ayenia limitaris, Manihot walkerae, Lesquerella thamnophila (syn. Physaria thamnophila), and Thymophylla tephroleuca. An eighth species, Physostegia correllii is under consideration for federal listing by the U.S. Fish and Wildlife Service. This paper assembles information on the background, biological status, major threats, and conservation to aid managers and the scientific community in restoring and managing these species.

Readability and Suitability of Local Disaster Preparedness Materials in Predominantly Hispanic Border Communities: A Case Study of Cameron County, Texas

Abstract Community awareness is a key component of disaster resilience and numerous agencies developed a plethora of preparedness materials. Previous studies evaluated national-level resources and social media content indicating that these efforts are not effectively reaching vulnerable populations, as the information is provided at or above the secondary education level. However, the local-specific content has been mostly overlooked in the analyses, subsequently neglecting the needs of areas with specific demographics and hazards, like predominantly Hispanic border communities. Thus, this study turns to local preparedness and mitigation materials, rather than general internet searches or national level documents. We analyze information provided on 239 webpages of local authorities in Cameron county in the southernmost tip of Texas. We evaluate: 1) the availability of languages and visual materials, 2) the reading difficulty level, and 3) the suitability of content. Our results demonstrate the lack of suitable and readable information provided on the local authorities’ websites with the average readability level implying “difficult” to “very confusing”, and the average suitability score equivalent to “below average/adequate”. Moreover, the lack of Spanish-language content indicates an under-utilization of the otherwise vernacular language. We discuss those results in the socio-cultural context of the border community.

The association of cancer-preventive lifestyle with colonoscopy screening use in border Hispanic adults along the Texas-Mexico border.

The relationship between engaging in two domains of cancer-preventive behaviors, lifestyle behaviors and colonoscopy screening, is unknown in Hispanic adults. Accordingly, the study examined the association between lifestyle and colonoscopy screening in Hispanic adults along the Texas-Mexico border, where there is suboptimal colorectal cancer prevention. Lifestyle behavior adherence and compliance with colonoscopy screening schedules were assessed using 2013-2023 data from the Cameron County Hispanic Cohorta population-based sample of Hispanic adults living along the Texas-Mexico border. The 2018 World Cancer Research Fund scoring system characterized healthy lifestyle engagement. Multivariable logistic regression quantified the association between lifestyle behaviors and colonoscopy screening. Among 914 Hispanic adults, there was a mean adherence score of 2.5 out of 7 for recommended behaviors. Only 33.0% (95% CI 25.64-41.39%) were up-to-date with colonoscopy. Complete adherence to fruit and vegetable (AOR [adjusted odds ratio] 5.2, 95% CI 1.68-16.30; p = 0.004), fiber (AOR 2.2, 95% CI 1.06-4.37; p = 0.04), and ultra-processed foods (AOR 2.8, 95% CI 1.30-6.21; p = 0.01) consumption recommendations were associated with up-to-date colonoscopy screening. Having insurance versus being uninsured (AOR 10.8, 95% CI 3.83-30.62; p < 0.001) and having local medical care versus in Mexico (AOR 7.0, 95% CI 2.26-21.43; p < 0.001) were associated with up-to-date colonoscopy. Adherence to dietary lifestyle recommendations was associated with being up-to-date with colonoscopy screenings. Those with poor dietary behavior are at risk for low-colonoscopy use. Improving lifestyle behaviors may complement colonoscopy promotion interventions. Healthcare accessibility influences up-to-date colonoscopy prevalence. Our findings can inform cancer prevention strategies for the Hispanic population.

Risk factors for overweight and obesity in Mexican American children and adolescents living on the Texas–Mexico border

BackgroundThis study aimed to compare the obesity rates between border-residing Mexican American children with the National Health and Nutritional Surveys (NHANES), and to examine the individual and household characteristics associated with weight status in these children.MethodsThis was a cross-sectional analysis of 354 children aged 8–18 years and their parents in the Cameron County Hispanic Cohort (CCHC) from 2014 to 2020. Children were categorized as healthy weight, overweight, class 1 obesity, class 2 obesity and class 3 obesity. The distribution of CCHC children's weight status was compared with Hispanic participants of the NHANES with matched age, sex, and the year of the interview. An ordinal least square regression analysis was conducted to assess the association between individual and household characteristics with CCHC children's weight status.ResultsApproximately 48.0% of CCHC children had a healthy weight, 17.9% were overweight, 22.2% were in class 1 obesity, 7.7% were in class 2 obesity, and 4.3% were in category 3. The weight distribution of the CCHC cohort was similar to that in the matched NHANES participants (p = 0.28). Being overweight was associated with higher household income (OR = 2.25, 95% CI: 1.01–5.02) while being in class 2 and class 3 obesity was associated with boys (Class 2 &amp;amp; 3 obesity: OR = 2.94, 95% CI: 1.27–6.81) and environmental factors such as parents' BMI (Class 2 and3 Obesity: OR = 1.13, 95% CI: 1.05–1.21).ConclusionsFamily socioeconomic status was positively associated with being overweight and Class 1 obesity, while gender and parent's BMI affected a child's likelihood of being class 2 and 3 obesity.

Discovery and Characterization of Two Highly Divergent Variants of a Novel Potyvirus Species Infecting Madagascar Periwinkle (Catharanthus roseus).

During the summer of 2022, a cluster of Madagascar periwinkle plants with white and mauve flowers were observed with foliar mild yellow mosaic symptoms on a private property in Harlingen, Cameron County, Texas. The symptoms were reproduced on mechanically inoculated periwinkle and Nicotiana benthamiana plants. Virions of 776 to 849 nm in length and 11.7 to 14.8 nm in width were observed in transmission electron microscopy of leaf dip preparations made from symptomatic periwinkle leaves. High-throughput sequencing (HTS) analysis of total RNA extracts from symptomatic leaves revealed the occurrence of two highly divergent variants of a novel Potyvirus species as the only virus-like sequences present in the sample. The complete genomes of both variants were independently amplified via reverse transcriptase PCR, cloned, and Sanger sequenced. The 5' and 3' of the genomes were acquired using random amplification of cDNA ends methodology. The assembled virus genomes were 9,936 and 9,944 nucleotides (nt) long, and they shared 99.9 to 100% identities with the respective HTS-derived genomes. Each genome encoded hypothetical polyprotein of 3,171 amino acids (aa) (362.6 kilodaltons [kDa]) and 3,173 aa (362.7 kDa), respectively, and they shared 77.3/84.4% nt/aa polyprotein identities, indicating that they represent highly divergent variants of the same Potyvirus species. Both genomes also shared below-species-threshold polyprotein identity levels with the most closely phylogenetically related known potyviruses, thus indicating that they belong to a novel species. The name periwinkle mild yellow mosaic virus (PwMYMV) is given to the potyvirus with complete genomes of 9,936 nt for variant 1 (PwMYMV-1) and 9,944 nt for variant 2 (PwMYMV-2). We propose that PwMYMV be assigned into the genus Potyvirus (family Potyviridae).

207 Building a community-academic partnership to facilitate translational research and identify and reduce barriers to mental healthcare services and resources in the Rio Grande Valley of South Texas

OBJECTIVES/GOALS: Clinical and epidemiological studies focusing on Hispanics/Latinos are often designed by academic researchers with little input from mental health professionals in underserved communities. Our objective is to establish an academic-community partnership in South Texas to help improve mental health outcomes of Hispanics. METHODS/STUDY POPULATION: Hispanics in the Rio Grande Valley (RGV, South Texas) are burdened with high rates of diabetes and obesity, and interventions have been identified for these conditions, but there is less information about strategies that may help improve their mental health status and address needs. We have explored mental health and psychological factors in Hispanics/Latinos in Latin America (Gil etal., 2021) and consider community participation in the research process to be an understudied topic. Thus, in the present study, we recruited mental health professionals in the RGV to establish an academic-community partnership as a strategy to facilitate translational research that focuses on RGV Hispanics. Partners worked as a team to generate information, identify problems and solutions, and design future projects. RESULTS/ANTICIPATED RESULTS: Our academic team (at the University of Texas Rio Grande Valley) successfully established a partnership with the Cameron County Mental Task Force (CCMHTF), a non-profit organization in South Texas that seeks to “meet the mental and behavioral health needs of the people” in South Texas. The CCMHTF comprises 12 board members that are representative of RGV mental health providers: counselors, social workers, academic clinicians, hospital and county employees, and mental and behavioral health facility providers/clinicians. Our partnership generated qualitative descriptions of the mental health needs of RGV Hispanics/Latinos and barriers to access and utilization of mental health services in South Texas. In the future (phase 2 of the study), we plan to report results of focus groups and mental health assessments. DISCUSSION/SIGNIFICANCE: Hispanics/Latinos are underrepresented in clinical/translational research, and this lack of representation is particularly true for Hispanics/Latinos living along the U.S.-Mexico border of the RGV, South Texas. Our academic-community partnership may serve as a model to facilitate translational research in underserved Hispanic communities.

A Laplacian regularized graph neural network for predictive modeling of multiple chronic conditions

Background and Goals: One of the biggest difficulties facing healthcare systems today is the prevalence of multiple chronic diseases (MCC). Mortality and the development of new chronic illnesses are more likely in those with MCC. Pre-existing diseases and risk factors specific to the patient have an impact on the complex stochastic process that guides the evolution of MCC. This study's goal is to use a brand-new Graph Neural Network (GNN) model to examine the connections between specific chronic illnesses, patient-level risk factors, and pre-existing conditions.Methods: We propose a graph neural network model to analyze the relationship between five chronic conditions (diabetes, obesity, cognitive impairment, hyperlipidemia, and hypertension). The proposed model adds a graph Laplacian regularization term to the loss function, which aims to improve the parameter learning process and accuracy of the GNN based on the graph structure. For validation, we used historical data from the Cameron County Hispanic Cohort (CCHC).Results: Evaluating the Laplacian regularized GNN on data from 600 patients, we expanded our analysis from two chronic conditions to five chronic conditions. The proposed model consistently surpassed a baseline GNN model, achieving an average accuracy of ≥89% across all combinations. In contrast, the performance of the standard model declined more markedly with the addition of more chronic conditions. The Laplacian regularization provided consistent predictions for adjacent nodes, beneficial in cases with shared attributes among nodes.Conclusions: The incorporation of Laplacian regularization in our GNN model is essential, resulting in enhanced node categorization and better predictive performance by harnessing the graph structure. This study underscores the significance of considering graph structure when designing neural networks for graph data. Future research might further explore and refine this regularization method for various tasks using graph-structured data.

A qualitative analysis of the effects of the COVID-19 response on low-income residents in Cameron County, Texas: Lessons for future pandemic response.

The coronavirus disease 2019 (COVID-19) pandemic had dramatic impacts throughout the United States (US). In Cameron County, Texas, along the Texas-Mexico border, the impacts of the virus were felt more severely than in most places in the US. Residents of the county, which has high rates of poverty, many multigenerational households, high levels of underlying conditions, and an uninsured population of almost 30 percent, were not only poised to be affected by the virus but also by the response policies put in place to contain it. This study seeks to add to the literature by examining the lived experiences of low-income individuals in Cameron County, Texas, as it relates to the COVID-19 response and their experiences with the response. To do this, we asked: How did the COVID-19 response affect low-income residents in Cameron County, Texas?

Presence and abundance of malaria vector species in Miami-Dade County, Florida

BackgroundMalaria outbreaks have sporadically occurred in the United States, with Anopheles quadrimaculatus serving as the primary vector in the eastern region. Anopheles crucians, while considered a competent vector, has not been directly implicated in human transmission. Considering the locally acquired Plasmodium vivax cases in Sarasota County, Florida (7 confirmed cases), Cameron County, Texas (one confirmed case), and Maryland (one confirmed case) in the summer of 2023. The hypothesis of this study is that major cities in the United States harbour sufficient natural populations of Anopheles species vectors of malaria, that overlap with human populations that could support local transmission to humans. The objective of this study is to profile the most abundant Anopheles vector species in Miami-Dade County, Florida—An. crucians and An. quadrimaculatus.MethodsThis study was based on high-resolution mosquito surveillance data from 2020 to 2022 in Miami-Dade County, Florida. Variations on the relative abundance of An. crucians and An. quadrimaculatus was assessed by dividing the total number of mosquitoes collected by each individual trap in 2022 by the number of mosquitoes collected by the same trap in 2020. In order to identify influential traps, the linear distance in meters between all traps in the surveillance system from 2020 to 2022 was calculated and used to create a 4 km buffer radius around each trap in the surveillance system.ResultsA total of 36,589 An. crucians and 9943 An. quadrimaculatus were collected during this study by the surveillance system, consisting of 322 CO2-based traps. The findings reveal a highly heterogeneous spatiotemporal distribution of An. crucians and An. quadrimaculatus in Miami-Dade County, highlighting the presence of highly conducive environments in transition zones between natural/rural and urban areas. Anopheles quadrimaculatus, and to a lesser extent An. crucians, pose a considerable risk of malaria transmission during an outbreak, given their high abundance and proximity to humans.ConclusionsUnderstanding the factors driving the proliferation, population dynamics, and spatial distribution of Anopheles vector species is vital for implementing effective mosquito control and reducing the risk of malaria outbreaks in the United States.

A Power Elite Alliance and Local Environmental Policy: Elon Musk in Cameron County

A Power Elite Alliance and Local Environmental Policy: <i>Elon Musk in Cameron County</i>

Evaluation of a Targeted COVID-19 Community Outreach Intervention: Case Report for Precision Public Health.

Cameron County, a low-income south Texas-Mexico border county marked by severe health disparities, was consistently among the top counties with the highest COVID-19 mortality in Texas at the onset of the pandemic. The disparity in COVID-19 burden within Texas counties revealed the need for effective interventions to address the specific needs of local health departments and their communities. Publicly available COVID-19 surveillance data were not sufficiently timely or granular to deliver such targeted interventions. An agency-academic collaboration in Cameron used novel geographic information science methods to produce granular COVID-19 surveillance data. These data were used to strategically target an educational outreach intervention named "Boots on the Ground" (BOG) in the City of Brownsville (COB). This study aimed to evaluate the impact of a spatially targeted community intervention on daily COVID-19 test counts. The agency-academic collaboration between the COB and UTHealth Houston led to the creation of weekly COVID-19 epidemiological reports at the census tract level. These reports guided the selection of census tracts to deliver targeted BOG between April 21 and June 8, 2020. Recordkeeping of the targeted BOG tracts and the intervention dates, along with COVID-19 daily testing counts per census tract, provided data for intervention evaluation. An interrupted time series design was used to evaluate the impact on COVID-19 test counts 2 weeks before and after targeted BOG. A piecewise Poisson regression analysis was used to quantify the slope (sustained) and intercept (immediate) change between pre- and post-BOG COVID-19 daily test count trends. Additional analysis of COB tracts that did not receive targeted BOG was conducted for comparison purposes. During the intervention period, 18 of the 48 COB census tracts received targeted BOG. Among these, a significant change in the slope between pre- and post-BOG daily test counts was observed in 5 tracts, 80% (n=4) of which had a positive slope change. A positive slope change implied a significant increase in daily COVID-19 test counts 2 weeks after targeted BOG compared to the testing trend observed 2 weeks before intervention. In an additional analysis of the 30 census tracts that did not receive targeted BOG, significant slope changes were observed in 10 tracts, of which positive slope changes were only observed in 20% (n=2). In summary, we found that BOG-targeted tracts had mostly positive daily COVID-19 test count slope changes, whereas untargeted tracts had mostly negative daily COVID-19 test count slope changes. Evaluation of spatially targeted community interventions is necessary to strengthen the evidence base of this important approach for local emergency preparedness. This report highlights how an academic-agency collaboration established and evaluated the impact of a real-time, targeted intervention delivering precision public health to a small community.

Sex-specific associations between adipokine profiles and carotid-intima media thickness in the Cameron County Hispanic Cohort (CCHC)

BackgroundAdipokines are hormones secreted from adipose tissue and are associated with cardiometabolic diseases (CMD). Functional differences between adipokines (leptin, adiponectin, and resistin) are known, but inconsistently reported associations with CMD and lack of studies in Hispanic populations are research gaps. We investigated the relationship between subclinical atherosclerosis and multiple adipokine measures.MethodsCross-sectional data from the Cameron County Hispanic Cohort (N = 624; mean age = 50; Female = 70.8%) were utilized to assess associations between adipokines [continuous measures of adiponectin, leptin, resistin, leptin-to-adiponectin ratio (LAR), and adiponectin-resistin index (ARI)] and early atherosclerosis [carotid-intima media thickness (cIMT)]. We adjusted for sex, age, body mass index (BMI), smoking status, cytokines, fasting blood glucose levels, blood pressure, lipid levels, and medication usage in the fully adjusted linear regression model. We conducted sexes-combined and sex-stratified analyses to account for sex-specificity and additionally tested whether stratification of participants by their metabolic status (metabolically elevated risk for CMD as defined by having two or more of the following conditions: hypertension, dyslipidemia, insulin resistance, and inflammation vs. not) influenced the relationship between adipokines and cIMT.ResultsIn the fully adjusted analyses, adiponectin, leptin, and LAR displayed significant interaction by sex (p < 0.1). Male-specific associations were between cIMT and LAR [β(SE) = 0.060 (0.016), p = 2.52 × 10–4], and female-specific associations were between cIMT and adiponectin [β(SE) = 0.010 (0.005), p = 0.043] and ARI [β(SE) = − 0.011 (0.005), p = 0.036]. When stratified by metabolic health status, the male-specific positive association between LAR and cIMT was more evident among the metabolically healthy group [β(SE) = 0.127 (0.015), p = 4.70 × 10–10] (p for interaction by metabolic health < 0.1). However, the female-specific associations between adiponectin and cIMT and ARI and cIMT were observed only among the metabolically elevated risk group [β(SE) = 0.014 (0.005), p = 0.012 for adiponectin; β(SE) = − 0.015 (0.006), p = 0.013 for ARI; p for interaction by metabolic health < 0.1].ConclusionAssociations between adipokines and cIMT were sex-specific, and metabolic health status influenced the relationships between adipokines and cIMT. These heterogeneities by sex and metabolic health affirm the complex relationships between adipokines and atherosclerosis.

Endothelial Dysfunction and Cardiometabolic Risk Factors in Mexican American Adults: The Cameron County Hispanic Cohort

Endothelial dysfunction assessed by impaired brachial flow-mediated dilation (FMD) predicts incident cardiovascular disease (CVD). We have previously shown that clustering of diabetes mellitus, obesity, and metabolic syndrome in young Hispanic patients was associated with subclinical atherosclerosis. This study aimed to assess determinants of impaired FMD response (%FMD), an earlier marker of atherosclerosis, in a population-based sample of asymptomatic Mexican Americans. Cardiometabolic biomarkers and FMD were obtained from 960 Cameron County Hispanic Cohort participants. Gender-specific median values of %FMD were used to categorize participants into those with %FMD below or above the median. The sample was further stratified into those younger and older than 55years. Survey-weighted logistic regression analyses were conducted to evaluate the effects of cardiometabolic biomarkers on the %FMD groups. The low %FMD group was significantly older, had higher visceral adipose tissue, systolic blood pressure, or plasma glucose, and had metabolic syndrome compared with those in the high %FMD group. Multivariable-adjusted age-stratified logistic regression analyses showed that in older participants, male gender (odds ratio [OR]=2.4 [1.4 to 4.2]) and having hypertension (OR=2.3 [1.3 to 4.3]) or prediabetes mellitus (OR=3.4 [1.5 to 7.5]) remained significantly associated with odds of low %FMD. In younger participants, high low-density lipoprotein (OR=2.8 [1.6 to 4.9]) or having the metabolic syndrome (OR=1.9 [1.1 to 3.6]) were significantly associated with odds of low %FMD. In conclusion, we found age-dependent associations between cardiometabolic biomarkers and an FMD response below the gender-specific median in a sample composed of Mexican Americans without previous CVD. Targeting specific risk factors by age may mitigate progression to incident CVD in this high-risk racial disparity group.

Population-Based Mini-Mental State Examination Norms in Adults of Mexican Heritage in the Cameron County Hispanic Cohort.

Accurately identifying cognitive changes in Mexican American (MA) adults using the Mini-Mental State Examination (MMSE) requires knowledge of population-based norms for the MMSE, a scale which has widespread use in research settings. To describe the distribution of MMSE scores in a large cohort of MA adults, assess the impact of MMSE requirements on their clinical trial eligibility, and explore which factors are most strongly associated with their MMSE scores. Visits between 2004-2021 in the Cameron County Hispanic Cohort were analyzed. Eligible participants were ≥18 years old and of Mexican descent. MMSE distributions before and after stratification by age and years of education (YOE) were assessed, as was the proportion of trial-aged (50-85- year-old) participants with MMSE <24, a minimum MMSE cutoff most frequently used in Alzheimer's disease (AD) clinical trials. As a secondary analysis, random forest models were constructed to estimate the relative association of the MMSE with potentially relevant variables. The mean age of the sample set (n = 3,404) was 44.4 (SD, 16.0) years old and 64.5% female. Median MMSE was 28 (IQR, 28-29). The percentage of trial-aged participants (n = 1,267) with MMSE <24 was 18.6% overall and 54.3% among the subset with 0-4 YOE (n = 230). The five variables most associated with the MMSE in the study sample were education, age, exercise, C-reactive protein, and anxiety. The minimum MMSE cutoffs in most phase III prodromal-to-mild AD trials would exclude a significant proportion of trial-aged participants in this MA cohort, including over half of those with 0-4 YOE.

Reverberations of Racial Violence: Critical Reflections on the History of the Border

Mexican Americans have a “hidden history” of being lynched in the United States (p. 211). As this anthology reveals, between 1910 and 1920, hundreds if not thousands of ethnic Mexicans were killed in Texas, and many were executed by the Texas Rangers. These state-sanctioned murders were not simply random acts of violence. This violence was instrumental in the making of Texas and in the integration of Texas into the United States. During the early twentieth century, thousands of land-hungry white Americans migrated to Texas, but the best lands were already held by Tejano families. As the price of land soared with the arrival of the railroads and commercial agriculture, Tejanos came under siege. Through legal challenges, intimidation, and white vigilantism, Tejanos lost their lands. In Cameron and Hidalgo Counties alone, Tejanos lost more than 180,000 acres (p. 254). Ethnic Mexicans who resisted dispossession and those who engaged in banditry were conflated as “wetback” outlaws. Anglos dealt with them by calling on Rangers such as Frank Hamer. Known as “the Angel of death,” the six-foot-three-inch 230-pound Hamer killed his first man at age sixteen (pp. 14, 163). Between 1915 and 1916, roaming bands of Rangers and their allies killed three hundred Mexicans (p. 255). During the Mexican Revolution, Rangers suspected Mexicans in Porvenir of helping revolutionary bandits, so they carried out one of the largest lynchings in U.S. history, killing fifteen Mexican men and boys (p. 95).

Abstract P322: Transcriptomic Analysis of Severe Obesity Identifies Novel Genes in Hispanic/Latino Populations With a High Burden of Disease

The US prevalence of severe obesity [(SevO), body mass index [BMI] ≥40 kg/m 2 )] is increasing at an alarming rate; women and Hispanic Latino populations have experienced among the greatest increases. While genome-wide association studies (GWAS) have identified &gt;1000 loci associated with body mass index, the function of much of this variation is unknown. Gene expression measures can ] link genetic variation and disease highlighting pathways for targeted therapeutic intervention, but to-date, few studies have examined the role of gene expression to identify molecular signatures associated with SevO. To this end, we leveraged extant whole blood (WB) RNA sequencing (RNAseq) data in 75 SevO cases and 116 controls (with BMI = 18-25) collected from randomly selected Mexican Americans in the Cameron County Hispanic Cohort (CCHC) to identify patterns associated with SevO. We used established protocols and alignment, yielding 18,565 genes after quality control. We applied DESeq2 to assess DE associated with SevO, using a negative binomial regression model with a gene-specific dispersion parameter, adjusted for sex, age, T2D, hypertension, hypercholesterolemia, and 10 probabilistic estimation of expression residual (PEER) factors. After FDR correction, 124 genes were significantly DE, including top genes C1RL , IL4R, and RGS16 . We identified several replications of the 124 genes in a transcriptomic follow-up study of 52 SevO cases and 59 normal weight controls- 20 genes displayed directionally consistent and FDR significant evidence of replication. We additionally identified several replications of the 124 genes in subcutaneous adipose tissue (SAT) from 19 NYC community volunteers, including for RGS16 , C1RL , and IL4R. 2- sample MR assessed causal associations between SevO and gene dysregulation, using SevO GWAS from DIAMANTE and CCHC eQTLs. Upregulated IL4R demonstrate pleiotropy, among other genes (e.g., REM2, ENGASE, and SCAP ). Collectively, these data demonstrate how transcriptomic studies may elevate understanding of SevO and inform efforts to reduce health disparities associated with SevO in HL populations.

Abstract P121: Varying Determinants of Endothelial Dysfunction by Age Group Among Mexican Americans

Endothelial dysfunction assessed by impaired brachial flow-mediated dilation (FMD) is a predictive factor of incident CVD. Most studies included small proportions of Hispanics or Latinos. We aimed to assess determinants of impaired FMD in a large population-based sample of asymptomatic Mexican-Americans. Methods: Cardiometabolic biomarkers, visceral adipose tissue (VAT), and FMD were obtained from 960 participants (57.9% females, mean age 52.1±0.9 years, age 18-85 years) from the Cameron County Hispanic Cohort. Sex-specific median values of %FMD were used to divide participants into two groups: those with FMD below (low %FMD) and above the median (high %FMD). The sample was further stratified into younger (age&lt;55 years) and older (age ≥ 55 years) age groups. Survey-weighted logistic regression analyses were conducted to evaluate the effects of factors on the %FMD groups. Results: There was a high prevalence of obesity (49.1%), hypertension (47.8%), diabetes (26.1%), hypercholesterolemia (46.7%), and metabolic syndrome (38.2%). The median FMD response was 4.2%±0.3% [3.8% (SE 0.4) in males and 4.5% (SE 0.4) in females]. Low %FMD group was significantly older, had higher VAT, SBP, or plasma glucose levels, and had metabolic syndrome compared to those in the high %FMD group. Multivariable-adjusted age-stratified logistic regression analyses showed that among older participants, male gender [OR =2.4 (1.4-4.2)] and having hypertension [OR=2.3 (1.3-4.3)] or pre-diabetes [OR=3.4 (1.5-7.5)] remained significantly associated with odds of low %FMD. Among younger participants, only high LDL [OR=2.8 (1.6-4.9)] or having metabolic syndrome [OR=1.9 (1.1-3.6)] were significantly associated with odds of low %FMD. Conclusion: We found age-dependent associations between cardiometabolic biomarkers and an FMD response below the gender-specific median in a population composed of Mexican-Americans without prior CVD. Targeting specific risk factors by age may mitigate progression to incident CVD in this high-risk group.

Abstract P666: Prevalence and Determinants of Left Ventricular Structural Abnormalities and Diastolic Dysfunction in Asymptomatic Mexican Americans Living in South Texas

Left ventricular hypertrophy (LVH) and concentric LV remodeling (CR) are precursors to development of clinical heart failure (HF), and are associated with obesity, hypertension (HTN) and diabetes mellitus (DM), which are highly prevalent in Mexican Americans. Our study aimed to determine the prevalence of subclinical LV structural abnormalities (LVH or CR) and LV diastolic dysfunction (LVDD) in a sample of asymptomatic Mexican Americans in South Texas and determinants of these LV structural abnormalities. Methods: Demographic, cardiometabolic biomarkers, and body composition data were obtained in 1208 participants (66.3% females, mean age 53.0±0.4 years) without any CVD history from the community-based Cameron County Hispanic Cohort study. Echocardiography was used to determine LVH/CR (linear method) and LVDD was assessed using national guidelines. Those with LV systolic dysfunction (n=26) were excluded. Abdominal adiposity was determined by abdominal visceral fat mass (VAT) from dual-energy X-ray absorptiometry. Weighted ordinal logistic regression analyses were conducted adjusting for demographic and clinical covariates. Results: Weighted prevalence rates of LVH (16.6% ± 1.7%), CR (40.7% ± 2.0%) and LVDD (24.2% ± 1.8%) were high in this cohort. In men, age (p&lt;0.01), obesity (p=0.04) and HTN (p&lt;0.001) were positively related to LV abnormalities. In women, age (p&lt;0.001), obesity (p&lt;0.01), education (p=0.02), HTN (p&lt;0.01) and DM (p&lt;0.01) were related to LV abnormalities. VAT was associated with LV abnormalities in women (p=0.02), but not in men (p=0.08). Conclusion: More than half of this asymptomatic Hispanic cohort had evidence of LV structural abnormalities and almost a quarter had subclinical diastolic dysfunction. We noted a gender interaction, with diabetes and abdominal obesity seen to be significantly related to cardiac abnormalities only in women. Identifying subclinical changes in cardiac function in these high-risk patients may mitigate progression to clinical HF by early intervention.