Identifying and removing barriers to cycling as a viable means of transportation in Houston, Texas

The citizens of Houston, Texas, spend much time commuting. It has repeatedly been named among the “Fattest Cities” by Men’s Fitness Magazine (The fittest and fattest cities in America – Men’s Fitness. ). Obesity is one of its major public health problems as Houstonians often do not engage in enough physical activity to help them maintain their ideal weights. The use of bicycles provides a healthy and ecological alternative to commuting by driving. However, because urban cyclists must often share the roads with motorized vehicles, cyclists are often exposed to high levels of emissions. As vulnerable users of the roadways, urban cyclists also face the threat of injury. Nevertheless, there are some programs that encourage the use of bicycles. Laws and ordinances not only reveal public policy relating to bicycling but are a means to develop policy which can encourage bicycling. ^

Identification of diabetic retinopathy genes through a genome-wide association study among Mexican-Americans from Starr County, Texas

To identify genetic susceptibility loci for severe diabetic retinopathy, 286 Mexican-Americans with type 2 diabetes from Starr County, Texas completed detailed physical and ophthalmologic examinations including fundus photography for diabetic retinopathy grading. 103 individuals with moderate-to-severe non-proliferative diabetic retinopathy or proliferative diabetic retinopathy were defined as cases for this study. DNA samples extracted from study subjects were genotyped using the Affymetrix GeneChip® Human Mapping 100K Set, which includes 116,204 single nucleotide polymorphisms (SNPs) across the whole genome. Single-marker allelic tests and 2- to 8-SNP sliding-window Haplotype Trend Regression implemented in HelixTreeTM were first performed with these direct genotypes to identify genes/regions contributing to the risk of severe diabetic retinopathy. An additional 1,885,781 HapMap Phase II SNPs were imputed from the direct genotypes to expand the genomic coverage for a more detailed exploration of genetic susceptibility to diabetic retinopathy. The average estimated allelic dosage and imputed genotypes with the highest posterior probabilities were subsequently analyzed for associations using logistic regression and Fisher's Exact allelic tests, respectively. To move beyond these SNP-based approaches, 104,572 directly genotyped and 333,375 well-imputed SNPs were used to construct genetic distance matrices based on 262 retinopathy candidate genes and their 112 related biological pathways. Multivariate distance matrix regression was then used to test hypotheses with genes and pathways as the units of inference in the context of susceptibility to diabetic retinopathy. This study provides a framework for genome-wide association analyses, and implicated several genes involved in the regulation of oxidative stress, inflammatory processes, histidine metabolism, and pancreatic cancer pathways associated with severe diabetic retinopathy. Many of these loci have not previously been implicated in either diabetic retinopathy or diabetes. In summary, CDC73, IL12RB2, and SULF1 had the best evidence as candidates to influence diabetic retinopathy, possibly through novel biological mechanisms related to VEGF-mediated signaling pathway or inflammatory processes. While this study uncovered some genes for diabetic retinopathy, a comprehensive picture of the genetic architecture of diabetic retinopathy has not yet been achieved. Once fully understood, the genetics and biology of diabetic retinopathy will contribute to better strategies for diagnosis, treatment and prevention of this disease.^

Characterization of Staphylococcus aureus isolates associated with pediatric carriage in Houston, Texas

Infections caused by Methicillin-resistant Staphylococcus aureus (MRSA) have been of great concern in hospitals due the difficulty in treating virulent, antibiotic resistant microorganisms in sensitive populations including children, the elderly, and immunocomprimised individuals. Since the late 1990's, MRSA infections have become a problem in the general community, and the strains of S. aureus that cause infections in the community are known to be genetically different than the hospital acquired strains. Community-acquired strains tend to be more virulent, affecting even relatively healthy individuals, and disease presentation tends to be more diverse than diseases observed in patients suffering from hospital-acquired strains. From the year 2000 to the present, there has been a significant increase in community-acquired infections in children, a population already particularly sensitive to S. aureus infection. Genotyping the strains of CA-MRSA circulating in the pediatric population is an important step in developing better antibiotic treatment strategies. Additionally, determining the carriage status of individuals in this population and comparing these data with strain genotypes will also be valuable in establishing prevention and control practices. ^

Epidemiology of isolated obstructive genitourinary defect in Texas: 1999--2003

Background. Obstructive genitourinary defects include all anomalies causing obstruction anywhere along the urinary tract. Previous studies have noted a large excess of males among infants affected by these types of defects. This is the first epidemiologic study focused solely on obstructive genitourinary defects (OGD). ^ Methods. Data on 1,683 mild and 302 severe cases of isolated OGD born between 1999 and 2003 and ascertained by the Texas Birth Defects Registry were compared to all births in Texas during the same time period. Adjusted prevalence odds ratios (POR) were calculated for infant sex, birth weight, gestational age, mother’s race/ethnicity, mother’s age, mother’s education, parity, birth year, start of prenatal care, multiple birth, and public health region of birth. Severe cases were defined as those cases that died prior to birth, died after birth, or underwent surgery for OGD in the first year of life. Cases of OGD that had other major birth defects besides OGD were excluded from this study. ^ Results. Severe cases of OGD were more likely than mild cases to have multiple obstructive genitourinary anomalies (37.8% vs. 18.9%) and bilateral defects (40.9% vs. 31.3%). Males had a significantly greater risk of OGD than females for both severe and mild cases: adjusted POR = 3.26 (95% CI = 2.45-4.33) and adjusted POR = 2.60 (95% CI = 2.33-2.90), respectively. Infants with both severe and mild OGD were more likely to be very preterm birth at birth compared with infants without OGD: crude POR of 16.19 (95% CI = 10.60-24.74) and 4.75 (95% CI = 3.54-6.37), respectively. Among the severe group, minority races had a decreased risk of OGD with an adjusted POR of 0.74 (95% CI = 0.55-0.98) compared with whites. Among the mild cases, increased rates of OGD were found in older mothers (adjusted POR = 1.10, 95% CI = 1.05-1.15), college/higher educated mothers (adjusted POR = 1.07, 95% CI = 1.01-1.13) and multiple births (adjusted POR = 1.28, 95% CI = 1.01-1.62). There was also a decreased risk of mild cases among black mothers compared to whites (adjusted POR = 0.63, 95% CI = 0.52-0.76). Compared to 1999, the prevalence of mild cases of OGD increased significantly over the 5 year study period with an adjusted POR of 1.10 (95% CI = 1.06-1.15) by 2003. ^ Conclusion. Risk factors of OGD for both severe and mild forms were male sex and preterm birth. Severe cases were more likely to have multiple OGD defects and be affected bilaterally. An increase in prevalence of mild cases of OGD over time and differences in rates of black, older, and higher educated mothers in mild cases may be attributed to ultrasound use. ^

Effectiveness of Texas Children's Hospital's Saturday Wellness Program for Children with special health care needs

Children with Special Health Care Needs comprise approximately 13% of children within the state of Texas. In addition to their primary diagnosis, it is estimated that approximately 18% of these children with special health care needs are overweight. Many times parents of children with special health care needs are extremely busy dealing with the daily responsibilities required to care for a child with a chronic illness, and thus, lose connections with their local communities and available resources for health needs such as obesity. Texas Children’s Hospital’s Wellness Program for Children with Special Health Care Needs is a family-centered wellness program to prevent obesity in this population; however, no formal evaluation of the program has been conducted. The purpose of this study was to assess the effectiveness of the Texas Children’s Saturday Wellness Program on weight status, nutrition knowledge, and the frequency of physical activity of children who participated in the program. A secondary data analysis was conducted with 50 children with special health care needs and their families who participated in the program during 2007 and 2008. A pre post-test study design was used with data collected immediately before and after participation in the 4 week program. Data measures included demographics (age, race, etc.), anthropometrics (height and weight), a quality of life survey focusing on nutrition and physical activity behaviors, and a knowledge survey on physical activity and nutrition. Of 50 participants, 33 (66%) completed the program. Children participating in the program showed a significant decrease in BMI (mean=29.83 to mean=29.22, BMI z score p<0.01), as well as frequency of physical activity (p<0.05) and knowledge (p<0.01). Texas Children’s Hospital’s wellness program for children with special health care needs provided a promising structure for a wellness program within a multi-ethnic special needs population; however, long term effect research is needed with a larger sample size and more comprehensive outcomes and process measures. Nonetheless, this program indicates the effectiveness and feasibility of a family-based approach to weight loss in children with special needs.^

Characterization of diabetes risk factors of elementary school children in low income areas of San Antonio, Texas

The number of children developing type-2 diabetes mellitus (T2DM) is increasing globally, especially in Western countries. Previous studies have indicated that low socioeconomic status (SES) is a contributing factor to diabetes. This study of children examined the relationship of socioeconomic status and two physiological measures that are risk factors for diabetes: the level of fasting capillary glucose (FCG) and hyperglycemia, in which there is an elevated amount of glucose in the blood. This study utilized data from the study entitled Bienester: A School-Based Diabetes Mellitus Prevention Program. The sample was 1,426 fourth grade students from 27 San Antonio Independent School District elementary schools. The dependent variable was FCG and the independent variable was the median family income associated with the student's zip code based on Census information. Other variables included body mass index, gender, and ethnicity. The statistical results showed no relationship between FCG, continuously defined, and income. In addition, there was no relationship between hyperglycemia and income. Furthermore, there was no relationship of FCG with BMI, gender, or ethnicity. Income measured at the zip code level is likely too aggregate and distal an influence to demonstrate an impact on FCG. Research should continue to examine risk factors associated with the onset of T2DM.^

Physician's adherence to CDC standards for physical activity counseling of older women in a cardiology practice in Texas---An exploratory study

Physical activity is an important health-promoting behavior to prevent and control chronic disease. Interventions to increase physical activity are vitally needed. Women are not meeting the recommended goals for physical activity - a behavior that has been shown to effectively reduce the incidence of chronic disease and the medical costs associated with treating it. Among many factors predicting physical activity and the different forms of interventions that have been applied, physician counseling is one potentially cost-effective approach that may produce at least modest effects on women's behavior. The Centers for Disease Control and Prevention has published standards for physician counseling of patients regarding physical activity. This study used a short questionnaire to assess the degree to which a group practice of cardiology physicians in Texas queried and discussed physical activity recommendations to older women that they treat and whether they are meeting the physical activity counseling goals of the Centers for Disease Control and Prevention. The majority of this group of physicians counseled patients without benefit of exploring patient behavior. Although these physicians "agreed" that physical activity delayed or prevented disease, the outcome suggests that low self-efficacy hampered efforts to counsel older women on this. Physicians' perceptions that counseling may be ineffective could explain the lower rate of physical activity counseling that does not meet the goals of the Centers for Disease Control and Prevention. ^

An analysis of Texas's school based HPV vaccine mandate: A public health risk communication failure: HPVETO!

Genital human papillomavirus (HPV) is of public health concern because persistent infection with certain HPV types can cause cervical cancer. In response to a nationwide push for cervical cancer legislation, Texas Governor Rick Perry bypassed the traditional legislative process and issued an executive order mandating compulsory HPV vaccinations for all female public school students prior to their entrance in the sixth grade. By bypassing the legislative process Governor Perry did not effectively mitigate the risk perception issues that arose around the need for and usefulness of the vaccine mandate. This policy paper uses a social policy paradigm to identify perception as the key intervening factor on how the public responds to risk information. To demonstrate how the HPV mandate failed, it analyzes four factors, economics, politics, knowledge and culture, that shape perception and influence the public's response. By understanding the factors that influence the public's perception, public health practitioners and policy makers can more effectively create preventive health policy at the state level. ^

Hazardous air pollutants and childhood lymphohematopoietic cancer in Southeast Texas, 1995--2004

Southeast Texas, including Houston, has a large presence of industrial facilities and has been documented to have poorer air quality and significantly higher cancer rates than the remainder of Texas. Given citizens’ concerns in this 4th largest city in the U.S., Mayor Bill White recently partnered with the UT School of Public Health to determine methods to evaluate the health risks of hazardous air pollutants (HAPs). Sexton et al. (2007) published a report that strongly encouraged analytic studies linking these pollutants with health outcomes. In response, we set out to complete the following aims: 1. determine the optimal exposure assessment strategy to assess the association between childhood cancer rates and increased ambient levels of benzene and 1,3-butadiene (in an ecologic setting) and 2. evaluate whether census tracts with the highest levels of benzene or 1,3-butadiene have higher incidence of childhood lymphohematopoietic cancer compared with census tracts with the lowest levels of benzene or 1,3-butadiene, using Poisson regression. The first aim was achieved by evaluating the usefulness of four data sources: geographic information systems (GIS) to identify proximity to point sources of industrial air pollution, industrial emission data from the U.S. EPA’s Toxic Release Inventory (TRI), routine monitoring data from the U.S. EPA Air Quality System (AQS) from 1999-2000 and modeled ambient air levels from the U.S. EPA’s 1999 National Air Toxic Assessment Project (NATA) ASPEN model. Further, once these four data sources were evaluated, we narrowed them down to two: the routine monitoring data from the AQS for the years 1998-2000 and the 1999 U.S. EPA NATA ASPEN modeled data. We applied kriging (spatial interpolation) methodology to the monitoring data and compared the kriged values to the ASPEN modeled data. Our results indicated poor agreement between the two methods. Relative to the U.S. EPA ASPEN modeled estimates, relying on kriging to classify census tracts into exposure groups would have caused a great deal of misclassification. To address the second aim, we additionally obtained childhood lymphohematopoietic cancer data for 1995-2004 from the Texas Cancer Registry. The U.S. EPA ASPEN modeled data were used to estimate ambient levels of benzene and 1,3-butadiene in separate Poisson regression analyses. All data were analyzed at the census tract level. We found that census tracts with the highest benzene levels had elevated rates of all leukemia (rate ratio (RR) = 1.37; 95% confidence interval (CI), 1.05-1.78). Among census tracts with the highest 1,3-butadiene levels, we observed RRs of 1.40 (95% CI, 1.07-1.81) for all leukemia. We detected no associations between benzene or 1,3-butadiene levels and childhood lymphoma incidence. This study is the first to examine this association in Harris and surrounding counties in Texas and is among the first to correlate monitored levels of HAPs with childhood lymphohematopoietic cancer incidence, evaluating several analytic methods in an effort to determine the most appropriate approach to test this association. Despite recognized weakness of ecologic analyses, our analysis suggests an association between childhood leukemia and hazardous air pollution.^

Self-reported participation and perceived barriers to exercise in South Texas Hispanic adults

National data show that Hispanics report low levels of physical activity. Limited information on barriers to exercise in this population exists in the literature. Surveys were administered to 398 Hispanic participants from two colonias in South Texas to investigate self-reported levels of and perceived barriers to exercise. Results show that 67.6% of respondents did not meet physical activity recommendations of at least 150 minutes per week, as compared to 55.6% nationally. Overall, the most frequently reported barriers included “lack of time”, “very tired” and “lack of self-discipline” to exercise. An exploratory factor analysis of the barriers reported by participants not meeting physical activity recommendations resulted in a three-factor structure. A unidimensional scale was found for participants meeting recommendations. Findings suggest that future interventions should be specific to gender and exercise level to address the high prevalence of inactivity in this population. ^

Associations between vaccination and childhood cancers in Texas counties

Background. In Dr. Mel Greaves "delayed-infection hypothesis," postponed exposure to common infections increases the likelihood of childhood cancer. Hygienic advancements in developed countries have reduced children's exposure to pathogens and children encounter common infectious agents at an older age with an immune system unable to deal with the foreign antigens. Vaccinations may be considered to be simulated infections as they prompt an antigenic response by the immune system. Vaccinations may regulate the risk of childhood cancer by modulating the immune system. The aim of the study was to determine if children born in Texas counties with higher levels of vaccination coverage were at a reduced risk for childhood cancer.^ Methods. We conducted a case-control study to examine the risk of childhood cancers, specifically leukemia, brain tumors, and non-Hodgkin lymphoma, in relation to vaccination rates in Texas counties. We utilized a multilevel mixed-effects regression model of the individual data from the Texas Cancer Registry (TCR) with group-level exposure data (i.e., the county- and public health region-level vaccination rates).^ Results. Utilizing county-level vaccination rates and controlling for child's sex, birth year, ethnicity, birth weight, and mother's age at child's birth the hepatitis B vaccine revealed negative associations with developing all cancer types (OR = 0.81, 95% CI: 0.67–0.98) and acute lymphoblastic leukemia (ALL) (OR = 0.63, 95% CI: 0.46–0.88). The decreased risk for ALL was also evident for the inactivated polio vaccine (IPV) (OR = 0.67, 95% CI: 0.49–0.92) and 4-3-1-3-3 vaccination series (OR = 0.62, 95% CI: 0.44-0.87). Using public health region vaccine coverage levels, an inverse association between the Haemophilus influenzae type b (Hib) vaccine and ALL (OR: 0.58; 95% CI: 0.42–0.82) was present. Conversely, the measles, mumps, and rubella (MMR) vaccine resulted in a positive association with developing non-Hodgkin lymphoma (OR = 2.81, 95% CI: 1.27–6.22). ^

Physician knowledge and beliefs toward hospice and the effect on hospice referral in El Paso, Texas

Hospice care has existed in the United States for over 20 years yet referral rates to hospice services are still well under the 180 days allowed by the Medicare Hospice Benefit. The average length of stay in El Paso is 56.8. ^ The aim of this study was to ascertain physician’s knowledge and attitudes towards hospice referral in the El Paso County. Particular issues to be addressed were: Physician’s knowledge of patient’s eligibility criteria and perception of the type of services provided by hospice. Other issues included, physician’s comfort level and willingness to determine terminal diagnosis and to discuss hospice services. Furthermore, physician’s perceptions of barriers to hospice referrals and how those perceptions differ between physicians who refer as compared to those who do not refer. ^ There were seven hypothesis tested to determine physicians knowledge and perceptions of hospice services. Using a mail-survey developed by Ogle, Mavis and Wang, this study surveyed 165 cardiologists, pediatric cardiologists, gastroenterologists, pulmonologists, neurologists, nephrologists, family practice, internists, oncologists, and pediatric oncologists. A t-test was used to test a comparison of means of categorical associations for all hypotheses. The data in the current study however, did not support the hypotheses tested. ^ Results indicated that physicians (52%) are knowledgeable with the eligibility criteria for hospice and that 95% are knowledgeable of the services hospice offers. Research findings appear to indicate physicians are not the hindering factor when making referrals to hospice. Physicians (46%) felt that one of the strongest barriers to hospice referrals is the patient/family unwillingness to accept hospice services. This offers an opportunity for future research in patients/families behavioral attitudes and beliefs toward death and dying issues and their perception of hospice services. ^

Evaluation of epidemiological and clinical factors in survival of patients with de novo myelodysplastic syndrome at the University of Texas MD Anderson cancer center

Little is known about epidemiological markers that are associated with survival of patients with myelodysplastic syndromes (MDS). We conducted a secondary case-based analysis of 465 de novo MDS patients from the University of Texas MD Anderson Cancer Center (UTMDACC). We investigated the association between demographic as well as occupational exposure markers and survival while incorporating known clinical markers of prognosis. In our patient population, 60.6% were men and the majority were white (93.1%). The distribution of MDS subtypes by the French–American–British (FAB) classification was 81 (19%) refractory anemia (RA), 46 (9.9%) refractory anemia with ringed sideroblasts (RARS), 57 (12.3%) chronic myelomonocytic leukemia (CMML), 173 (37.2%) RA with excess blasts (RAEB), and 86 (18.5%) RAEB in transformation (RAEBT). We found that those older at diagnosis (> 60 years of age) (HR = 1.68, CI = 1.26-2.25) were at a higher risk of dying compared to younger patients. Similarly, high pack years of smoking (>= 30 pack years of smoking) (HR = 1.34, CI = 1.02-1.74), and agricultural chemical exposure (HR = 1.61, CI = 1.05-2.46) were significantly associated with overall lower survival when compared to patients with none or medium exposures. Among clinical markers, greater than 5% bone marrow blasts (HR = 1.81 CI = 1.27-2.56), poor cytogenetics (HR = 3.20, CI = 2.37-4.33)), and platelet cytopenias (<100000/ul) (HR = 1.46, CI = 1.11-1.92) were also significantly associated with overall MDS survival.^ The identification of epidemiological markers could help physicians stratify patients and customize treatment strategies to improve the outcome of MDS based on patient lifestyle information such as smoking exposure and agrochemical exposure. We hope that this study highlights the impact of these exposures in MDS prognosis.^

Antibody response to Panton-Valentine Leukocidin, a Staphylococcus aureus virulence factor, in pediatric patients from Texas Children's Hospital in Houston, Texas

Staphylococcus aureus is an important human pathogen of global health significance, whose frequency is increasing and whose persistence and versatility allow it to remain established in communities worldwide. An observed significant increase in infections, particularly in children with no predisposing risk factors or medical conditions, led to an investigation into pediatric humoral immune response to Panton-Valentine Leukocidin (PVL) and to other antigens expressed by S. aureus that represent the important classes of virulence activities. Patients who were diagnosed with staphylococcal infections were enrolled (n=60), and serum samples collected at the time of admission were analyzed using ELISA and Western blot to screen for immune response to the panel of recombinant proteins. The dominant circulating immunoglobulin titers in this pediatric population were primarily IgG, were specific, and were directed against LukF and LukS, while suppression of other important virulence factors in the presence of PVL was suggested. Patients with invasive infections (osteomyelitis, pneumonia or myositis) had higher titers against LukF and LukS compared to patients with non-invasive infections (abscesses, cellulitis or lymphadenitis). In patients with osteomyelitis, antibody responses to LukF and LukS were higher than antibody responses to any other virulence factor examined. This description of immune response to selected virulence factors of S. aureus caused by isolates of the USA300 lineage in children is novel. Antibody titers also correlated with markers of inflammation. The significance of these correlations remains to be understood.^

An investigation into the relationship between screen time, consumption of advertised foods, and physical activity among Texas 4th grade elementary school children

Background. The high prevalence of obesity among children has spurred creation of a list of possible causative factors, including the advertising of foods of minimal nutritional value, a decrease in physical activity, and increased media use. Few studies show prevalence rates of these factors among large cohorts of children. ^ Methods. Using data from the 2004-2005 School Physical Activity and Nutrition project (SPAN), a secondary analysis of 7907 4th-grade children (mean age 9.74 years) was conducted. In addition, a comic-book–based intervention that addressed advertised food consumption, physical activity, and media use was developed and evaluated using a pre-post test design among 4th-grade children in an urban school district. ^ Results. Among a cohort of 4th-grade children across the state of Texas, children who had more than 2 hours of video game or computer time the previous day were more than twice as likely to drink soda and eat candy or pastries. In addition, children who watched more than 2 hours of TV the previous day were more than three times as likely to consume chips, punch, soda, candy, frozen desserts, or pastries (AOR 3.41, 95% CI: 1.58, 7.37). A comic-book based intervention held great promise and acceptance among 4th-grade children. Outcome evaluation showed that while results moved in a positive direction, they were not statistically significant. ^ Conclusion. Statistically significant associations were found between screen time and eating various types of advertised food. The comic book intervention was widely accepted by the children exposed to it, and pre-post surveys indicated they moved constructs in a positive direction. Further research is needed to look at more specific ways in which children are exposed to TV, and the relationship of the TV viewing time with their consumption of advertised foods. In addition, researchers should look at comic book interventions more closely and attempt to utilize them in more in studies with a longer follow-up time. ^