Prenatal interphase FISH diagnosis of PLP1 duplication associated with Pelizaeus–Merzbacher disease

A submicroscopic genomic duplication in Xq22.2 that contains the entire proteolipid protein 1 gene (PLP1) is responsible for the majority of Pelizaeus–Merzbacher disease (PMD) patients. We previously developed an interphase FISH assay to screen for PLP1 duplications in PMD patients using peripheral blood and lymphoblastoid cell lines. This assay has been utilized as a clinical diagnostic test in our cytogenetics laboratory. To expand usage of the interphase FISH assay to prenatal diagnosis of PLP1 duplications, we examined three PMD families with PLP1 duplications utilizing aminiotic fluid samples. In two families the FISH assay revealed fetuses with PLP1 duplications, whereas the other fetus showed a normal copy number of PLP1. Haplotype analyses, as well as an additional FISH analysis using postnatal blood samples, confirmed the results of the prenatal analyses. Our study demonstrates utility of the interphase FISH assay in the prenatal diagnosis of PLP1 duplications in PMD. Copyright © 2001 John Wiley & Sons, Ltd.     

Plant and soil responses to biosolids application following forest fire

Soil stability and revegetation is a great concern following forest wildfires. Biosolids application might enhance revegetation efforts and enhance soil stability. In May 1997, we applied Metro Wastewater Reclamation District (Denver, CO, USA) composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO to improve soil C and N levels and help establish eight native, seeded grasses. The soils on the site belong to the Sphinx series (sandy-skeletal, mixed, frigid, shallow Typic Ustorthents). Vegetation and soils data were collected for four years following treatment. During the four years following treatment, total plant biomass ranged from approximately 50 to 230 g m(-2) and generally increased with increasing biosolids application. The percentage of bare ground ranged from 4 to 58% and generally decreased with increasing biosolids rate. Higher rates of biosolids application were associated with increased concentrations of N, P, and Zn in tissue of the dominant plant species, streambank wheatgrass [Elymus lanceolatus (Scribn. & J.G. Sm) Gould subsp. lanceolatus], relative to the unamended, unfertilized control. At two months following biosolids application (1997), total soil C and N at soil depths of 0 to 7.5, 7.5 to 15, and 15 to 30 cm showed significant (P < 0.05) linear increases (r2 > 0.88) as biosolids rate increased. The surface soil layer also showed this effect one year after application (1998). For Years 2 through 4 (1999-2001) following treatment, soil C and N levels declined but did not show consistent trends. The increase in productivity and cover resulting from the use of biosolids can aid in the rehabilitation of wildfire sites and reduce soil erosion in ecosystems similar to the Buffalo Creek area.     

Differentiating nonpoint sources of deisopropylatrazine in surface water using discrimination diagrams

Pesticide degradates account for a significant portion of the pesticide load in surface water. Because pesticides with similar structures may degrade to the same degradate, it is important to distinguish between different sources of parent compounds that have different regulatory and environmental implications. A discrimination diagram, which is a sample plot of chemical data that differentiates between different parent compounds, was used for the first time to distinguish whether sources other than atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) contributed the chlorinated degradate, deisopropylatrazine (DIA; 6-chloro-N-ethyl-1,3,5-triazine-2,4-diamine) to the Iroquois and Delaware Rivers. The concentration ratio of deisopropylatrazine to deethylatrazine [6-chloro-N-(1-methylethyl)1,3,5-triazine-2,4-diamine], called the D2R, was used to discriminate atrazine as a source of DIA from other parent sources, such as cyanazine (2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino]-2-methylpropionitrile) and simazine (6-chloro-N,N'-diethyl-1,3,5-triazine-2,4diamine). The ratio of atrazine to cyanazine (ACR) used in conjunction with the D2R showed that after atrazine, cyanazine was the main contributor of DIA in surface water. The D2R also showed that cyanazine, and to a much lesser extent simazine, contributed a considerable amount (approximately 40%) of the DIA that was transported during the flood of the Mississippi River in 1993. The D2R may continue to be a useful discriminator in determining changes in the nonpoint sources of DIA in surface water as cyanazine is currently being removed from the market.     

Biosolids applications affect runoff water quality following forest fire

Soil erosion and nutrient losses are great concerns following forest wildfires. Biosolids application might enhance revegetation efforts while reducing soil erodibility. Consequently, we applied Denver Metro Wastewater District composted biosolids at rates of 0, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO to increase plant cover and growth. Soils were classified as Ustorthents, Ustochrepts, and Haploborols. Simulated rainfall was applied for 30 min at a rate of 100 mm h(-1) to 3- x 10-m paired plots. Biosolids application rates did not significantly affect mean total runoff (p < 0.05). Sediment concentrations were significantly greater (p < 0.05) from the control plots compared with the plots that had received the 80 Mg biosolids ha(-1) rate. Biosolids application rate had mixed effects on water-quality constituents; however, concentrations of all runoff constituents for all treatment rates were below levels recommended for drinking water standards, except Pb. Biosolids application to this site increased plant cover, which should provide erosion control.     

A SURVEY OF THE MICROBIAL QUALITY OF RECYCLED HOUSEHOLD GRAYWATER1

ABSTRACT: In arid regions where populations are expanding and water is scarce, people are searching for ways to conserve and reuse water. One way homeowners can conserve water is by recycling graywater‐wastewater from household sinks, showers, bathtubs, and washing machines. Graywater is used mostly for landscape irrigation. Since graywater is wastewater, reusing it raises concerns about disease transmission, either by contact with the water or the irrigated soil. The purpose of this study was to assess how factors such as number and age of household occupants, types of graywater storage, and sources of graywater used affect the microbial quality of graywater and soil irrigated with graywater. Samples were collected over twelve months from eleven Tucson, Arizona households recycling graywater. Samples of graywater, soil irrigated by graywater, and soil irrigated by potable water were collected. We found that graywater irrigation causes a statistically significant increase in levels of fecal coliforms in soil when compared to soil irrigated with potable water. Graywater from the kitchen sink significantly increases levels of these bacteria in water and soil. Children also cause a statistically significant increase in fecal coliform levels in graywater and soil, possibly introducing a small amount of additional risk in graywater reuse.