The Impacts of Exposure to Environmental Risk on Physical and Mental Health in a Small Geographic Community in Houston, TX.

Previous research has shown that communities with low average socioeconomic status (SES) and majority minority populations are more likely to be exposed to industrial buildings, waste facilities, and poor infrastructure compared to white communities with higher average SES. While some studies have demonstrated linkages between exposures to specific environmental contaminates within these communities and negative health outcomes, little research has analyzed the effects of environmental contaminants on the mental and physical health of these populations. A cross-sectional survey collected data from residents of Manchester, a small neighborhood in Houston, TX, that is characterized by industrial sites, unimproved infrastructure, nuisance flooding, and poor air quality. Our study (N = 109) utilized the 12 item Short Form Health Survey version 2 (SF12v2) to assess the general mental and physical health of the community. The community as a whole had reduced physical health scores compared to U.S. national averages. The time residents had lived in the neighborhood was also correlated with a reported reduction in physical health scores (r2 = 0.136; p-value <0.001). The association between time lived in the neighborhood and poorer health scores remained after adjusting for age, race, and gender (coef = -0.27, p-value <0.001). Mental health scores were within national averages and time spent living in the neighborhood did not appear to negatively impact respondent's mental health scores. These findings point to the need for more research to determine the potential for additive physical and mental health impacts in long-term residents in neighborhoods characterized by environmental justice issues.

Functional characterization of the gene cluster from Pseudomonas syringae pv. phaseolicola NPS3121 involved in synthesis of phaseolotoxin.

Pseudomonas syringae pv. phaseolicola is the causal agent of halo blight disease of beans (Phaseolus vulgaris L.), which is characterized by water-soaked lesions surrounded by a chlorotic halo resulting from the action of a non-host-specific toxin known as phaseolotoxin. This phytotoxin inhibits the enzyme ornithine carbamoyltransferase involved in arginine biosynthesis. Different evidence suggested that genes involved in phaseolotoxin production were clustered. Two genes had been previously identified in our laboratory within this cluster: argK, which is involved in the immunity of the bacterium to its own toxin, and amtA, which is involved in the synthesis of homoarginine. We sequenced the region around argK and amtA in P. syringae pv. phaseolicola NPS3121 to determine the limits of the putative phaseolotoxin gene cluster and to determine the transcriptional pattern of the genes comprising it. We report that the phaseolotoxin cluster (Pht cluster) is composed of 23 genes and is flanked by insertion sequences and transposases. The mutation of 14 of the genes within the cluster lead to a Tox(-) phenotype for 11 of them, while three mutants exhibited low levels of toxin production. The analysis of fusions of selected DNA fragments to uidA, Northern probing, and reverse transcription-PCR indicate the presence of five transcriptional units, two monocistronic and three polycistronic; one is internal to a larger operon. The site for transcription initiation has been determined for each promoter, and the putative promoter regions were identified. Preliminary results also indicate that the gene product of phtL is involved in the regulation of the synthesis of phaseolotoxin.