Neighbourhood deprivation and small-for-gestational-age term births in the United States

Residential context has received increased attention as a possible contributing factor to race/ethnic and socioeconomic disparities in birth outcomes in the United States. Utilizing vital statistics birth record data, this study examined the association between neighbourhood deprivation and the risk of a term small-for-gestational-age (SGA) birth among non-Hispanic whites and non-Hispanic blacks in eight geographic areas: Baltimore City, Baltimore County, Montgomery County and Prince Georges County in Maryland, 16 pooled cities in Michigan, Durham County and Wake County in North Carolina, and Philadelphia, Pennsylvania. Multilevel random intercept logistic regression models were employed and statistical tests were performed to examine if the association between neighbourhood deprivation and SGA varied by race/ethnicity and study site. The risk of term SGA was higher among non-Hispanic blacks (range: 10.8%–17.5%) than non-Hispanic whites (range: 5.1%–9.2%) in all areas and it was higher in cities than in suburban locations. In all areas, non-Hispanic blacks lived in more deprived neighbourhoods than non-Hispanic whites. However, the adjusted associations between neighbourhood deprivation and term SGA did not vary significantly by race/ethnicity or study site. The summary fully-adjusted pooled odds ratios, indicating the effect of one standard deviation increase in the deprivation score, were 1.15 [95% CI: 1.08–1.22] for non-Hispanic whites and 1.09 [95% CI: 1.05–1.14] for non-Hispanic blacks. Thus, neighbourhood deprivation was weakly associated with term SGA among both non-Hispanic whites and non-Hispanic blacks

BREAST-MILK MONITORING TO MEASURE MICHIGAN'S CONTAMINATION WITH POLYBROMINATED BIPHENYLS

In 1973 and 1974, several thousand Michigan dairy farms were contaminated by polybrominated biphenyls (P.B.B.) as the result of an industrial accident. An unknown quantity of contaminated meat and dairy products entered the food chain before contaminated farms were quarantined. To determine the extent of human exposure, P.B.B. concentrations were measured in human breast milk, which was collected in a random-sample survey from nursing mothers throughout Michigan. 96% of 53 samples from Michigan's lower peninsula and 43% of 42 samples from the less densely populated upper peninsula contained detectable levels of P.B.B. These data indicate that about 8 million of Michigan's 9[middle dot]1 million residents have detectable body burdens of P.B.B.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22528/1/0000072.pd

Maternal Weathering and Risk of Preterm Delivery

Objectives. We compared the association between advancing maternal age and risk of preterm delivery across 4 groups (Black smokers, Black nonsmokers, White smokers, White nonsmokers) and within the context of neighborhood deprivation levels

The Tuberous Sclerosis Complex Regulates Trafficking of Glucose Transporters and Glucose Uptake

Human cancers often display an avidity for glucose, a feature that is exploited in clinical staging and response monitoring by using 18F-fluoro-deoxyglucose (FDG) positron emission tomography. Determinants of FDG accumulation include tumor blood flow, glucose transport, and glycolytic rate, but the underlying molecular mechanisms are incompletely understood. The phosphoinositide-3 kinase/Akt/mammalian target of rapamycin complex (mTORC) 1 pathway has been implicated in this process via the hypoxia-inducible factor alpha-dependent expression of vascular endothelial growth factor and glycolytic enzymes. Thus, we predicted that tumors with elevated mTORC1 activity would be accompanied by high FDG uptake. We tested this hypothesis in eight renal angiomyolipomas in which the loss of tuberous sclerosis complex (TSC) 1/2 function gave rise to constitutive mTORC1 activation. Surprisingly, these tumors displayed low FDG uptake on positron emission tomography. Exploring the underlying mechanisms in vitro revealed that Tsc2 regulates the membrane localization of the glucose transporter proteins (Glut)1, Glut2, and Glut4, and, therefore, glucose uptake. Down-regulation of cytoplasmic linker protein 170, an mTOR effector, rescued Glut4 trafficking in Tsc2−/− cells, whereas up-regulation of Akt activity in these cells was insufficient to redistribute Glut4 to the plasma membrane. The effect of mTORC1 on glucose uptake was confirmed using a liver-specific Tsc1- deletion mouse model in which FDG uptake was reduced in the livers of mutant mice compared with wild-type controls. Together, these data show that mTORC1 activity is insufficient for increased glycolysis in tumors and that constitutive mTOR activity negatively regulates glucose transporter trafficking

The Development of a Standardized Neighborhood Deprivation Index

Census data are widely used for assessing neighborhood socioeconomic context. Research using census data has been inconsistent in variable choice and usually limited to single geographic areas. This paper seeks to a) outline a process for developing a neighborhood deprivation index using principal components analysis and b) demonstrate an example of its utility for identifying contextual variables that are associated with perinatal health outcomes across diverse geographic areas. Year 2000 U.S. Census and vital records birth data (1998–2001) were merged at the census tract level for 19 cities (located in three states) and five suburban counties (located in three states), which were used to create eight study areas within four states. Census variables representing five socio-demographic domains previously associated with health outcomes, including income/poverty, education, employment, housing, and occupation, were empirically summarized using principal components analysis. The resulting first principal component, hereafter referred to as neighborhood deprivation, accounted for 51 to 73% of the total variability across eight study areas. Component loadings were consistent both within and across study areas (0.2–0.4), suggesting that each variable contributes approximately equally to “deprivation” across diverse geographies. The deprivation index was associated with the unadjusted prevalence of preterm birth and low birth weight for white non-Hispanic and to a lesser extent for black non-Hispanic women across the eight sites. The high correlations between census variables, the inherent multidimensionality of constructs like neighborhood deprivation, and the observed associations with birth outcomes suggest the utility of using a deprivation, index for research into neighborhood effects on adverse birth outcomes

The Duration of Zidovudine Benefit in Persons With Asymptomatic HIV Infection: Prolonged Evaluation of Protocol 019 of the AIDS Clinical Trials Group

Objective.—To determine the durability of zidovudine-induced delay in clinical progression of asymptomatic human immunodeficiency virus (HIV) disease and to assess the relationship between this effect and the entry CD4+ cell count.Design and Interventions.—Extended follow-up data from subjects participating in protocol 019 of the AIDS [acquired immunodeficiency syndrome] Clinical Trials Group were examined. Subjects were offered a total daily dose of 500 mg of open-label zidovudine after the unblinding of the original randomized trial in 1989. Original treatment groups included placebo, 500 mg of zidovudine, or 1500 mg of zidovudine daily in divided doses. Three distinct analyses were conducted to assess the duration of zidovudine's effect on progression to AIDS or death: (1) analysis of all follow-up information from all subjects, (2) analysis of all subjects but with follow-up of original placebo-assigned subjects censored at the time open-label zidovudine was initiated, and (3) analysis of the effect of initiating zidovudine in subjects initially assigned to receive placebo.Setting.—University-based and university-affiliated AIDS research clinics participating in AIDS Clinical Trials Group protocol 019.Patients.—A total of 1565 asymptomatic HIV-infected subjects with entry CD4+ cell counts less than 0.50×109/L (500/μL).Main Outcome Measure.—Time to progression to AIDS or death.Results.—During follow-up of up to 4.5 years (mean, 2.6 years), 232 subjects progressed to AIDS or died. In each of the three analyses described herein, zidovudine was associated with a significant (P=.008,.004,.007) decrease in the risk of such progression. However, each of these analyses also indicated a decreasing placebo:zidovudine relative risk with duration of use (P=.002,.08,.04), suggesting a nonpermanent effect. The duration of benefit appeared to be related to entry CD4+ cell count, with greater benefit in those with higher counts at entry. No significant differences in survival were found between those originally randomized to zidovudine or placebo.Conclusions.—Zidovudine at 500 mg/d caused a significant delay in progression to AIDS or death, but its earlier use in asymptomatic disease was not associated with an additional prolongation of survival compared with delayed initiation. The delay in progression diminished over time especially in subjects with entry CD4+ cell counts less than 0.30×109/L (300/μL). Treatment strategies that alter drug regimens before the loss of zidovudine benefit should be explored.(JAMA. 1994;272:437-442