Uptake and fate of hexahydro-1,3,5-trinitro-1,3,5-triazine by Chrysopogon zizanioides

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a nitramine compound that has been used heavily by the military as an explosive. Manufacturing, use, and disposal of RDX have led to several contamination sites across the United States. RDX is both persistent in the environment and a threat to human health, making its remediation vital. The use of plants to extract RDX from the soil and metabolize it once it is in the plant tissue, is being considered as a possible solution. In the present study, the tropical grass Chrysopogon zizanioides was grown hydroponically in the presence RDX at 3 different concentration levels: 0.3, 1.1, and 2.26 ppm. The uptake of RDX was quantified by high performance liquid chromatography (HPLC) analysis of media samples taken every 6 hr during the first 24 hr and then daily over a 30-day experimental period. A rapid decrease in RDX concentration in the media of both controls and plant treatments was seen within the first 18 hours of the experiment with the greatest loss in RDX over time occurring within the first 6 hours of exposure. The loss was similar in both controls and plant exposures and possibly attributed to rapid uptake by the containers. A plant from one treatment at each of the three concentrations was harvested at Day 10, 20 and 30 throughout the experiment and extracted to determine the localization of RDX within the tissue and potentially identify any metabolites on the basis of differing retention times. Of the treatments containing 0.3, 1.1, and 2.26 ppm RDX, 13.1%, 18.3%, and 24.2% respectively, was quantified in vetiver extracts, with the majority of the RDX being localized to the roots. All plants not yet harvested were harvested on Day 30 of the experiment. A total of three plants exposed to each concentration level as well as the control, were extracted and analyzed with HPLC to determine amount of RDX taken up, localization of RDX within the plant tissue, and potentially identify any metabolites. Phytotoxicity of RDX to vetiver was also monitored. While a loss in biomass was observed in plants exposed to all the different concentrations of RDX, control plants grown in media not exposed to RDX showed the greatest biomass loss of all the treatments. There was also little variation in chlorophyll content between the different concentration treatments with RDX. This preliminary greenhouse study of RDX uptake 10 by Chrysopogon zizanioides will help indicate the potential ability of vetiver to serve as a plant system in the phytoremediation of RDX.

Culturally sensitive cancer education: Effect on knowledge, cancer fatalism, and participation in mobile mammography screening among African-American women

Purpose. To evaluate the effectiveness of a culturally sensitive educational intervention that used an African American lay survivor of breast cancer to increase knowledge of breast cancer, decrease cancer fatalism, and increase participation in mobile mammography screening among African American women. ^ Design. Experimental pretest/posttest design. ^ Setting. Two predominantly African American churches in a large southwestern metropolitan city. ^ Sample. Participants included 93 African American women, 40 years of age and older. Participants were randomly assigned to an intervention group (n = 48) or a control group (n = 45). ^ Methods. Pretest and post-test measures included the Breast Cancer Knowledge Test and the Powe Fatalism Inventory. In addition, demographic and breast screening practices were collected by questionnaire. The intervention group received a breast cancer educational testimonial from an African American lay survivor of breast cancer, who answered questions and addressed concerns, while stressing the importance of taking responsibility for one's own health and spreading disease prevention messages throughout the African American community. The control group viewed the American Cancer Society “Keep In Touch” video prepared specifically for African American women. Participants in both groups were given culturally sensitive educational materials designed to increase knowledge about breast cancer, and were instructed on breast self-examination by an African American registered nurse, using ethnically appropriate breast models. In addition, after the post-test, all eligible participants were given an opportunity to have a free mammogram via a mobile mammography unit parked at the church. ^ Findings. Participants in the intervention group had a significant increase (p = .03) in knowledge of breast cancer and a significant decrease (p = .000) in fatalism scores compared to those individuals in the control group. The intervention group had a 61% participation rate in screening, while the control group had a 39% participation rate in screening. However, the difference was not statistically significant at the .05 level (p = .07). ^ Conclusions. Results demonstrate that culturally sensitive breast cancer education is successful in increasing knowledge and decreasing cancer fatalism. While there was a trend toward behavior change in the intervention group, more research needs to be done in this area. ^

The Spanish translation, cultural adaptation and validation of the Powe Fatalism Inventory

Background/significance. The scarcity of reliable and valid Spanish language instruments for health related research has hindered research with the Hispanic population. Research suggests that fatalistic attitudes are related to poor cancer screening behaviors and may be one reason for low participation of Mexican-Americans in cancer screening. This problem is of major concern because Mexican-Americans constitute the largest Hispanic subgroup in the U.S.^ Purpose. The purposes of this study were: (1) To translate the Powe Fatalism Inventory, (PFI) into Spanish, and culturally adapt the instrument to the Mexican-American culture as found along the U.S.-Mexico border and (2) To test the equivalence between the Spanish translated, culturally adapted version of the PFI and the English version of the PFI to include clarity, content validity, reading level and reliability.^ Design. Descriptive, cross-sectional.^ Methods. The Spanish language translation used a translation model which incorporates a cultural adaptation process. The SPFI was administered to 175 bilingual participants residing in a midsize, U.S-Mexico border city. Data analysis included estimation of Cronbach's alpha, factor analysis, paired samples t-test comparison and multiple regression analysis using SPSS software, as well as measurement of content validity and reading level of the SPFI. ^ Findings. A reliability estimate using Cronbach's alpha coefficient was 0.81 for the SPFI compared to 0.80 for the PFI in this study. Factor Analysis extracted four factors which explained 59% of the variance. Paired t-test comparison revealed no statistically significant differences between the SPFI and PFI total or individual item scores. Content Validity Index was determined to be 1.0. Reading Level was assessed to be less than a 6th grade reading level. The correlation coefficient between the SPFI and PFI was 0.95.^ Conclusions. This study provided strong psychometric evidence that the Spanish translated, culturally adapted SPFI is an equivalent tool to the English version of the PFI in measuring cancer fatalism. This indicates that the two forms of the instrument can be used interchangeably in a single study to accommodate reading and speaking abilities of respondents. ^

THE CHLOREX TREATABILITY STUDY: ENVIRONMENTAL FATE IN FACULTATIVE ANAEROBIC AND AEROBIC WASTE STABILIZATION PONDS (BIODEGRADATION, VOLATILIZATION, SORPTION, PRIORITY POLLUTANTS)

The efficacy of waste stabilization lagoons for the treatment of five priority pollutants and two widely used commercial compounds was evaluated in laboratory model ponds. Three ponds were designed to simulate a primary anaerobic lagoon, a secondary facultative lagoon, and a tertiary aerobic lagoon. Biodegradation, volatilization, and sorption losses were quantified for bis(2-chloroethyl) ether, benzene, toluene, naphthalene, phenanthrene, ethylene glycol, and ethylene glycol monoethyl ether. A statistical model using a log normal transformation indicated biodegradation of bis(2-chloroethyl) ether followed first-order kinetics. Additionally, multiple regression analysis indicated biochemical oxygen demand was the water quality variable most highly correlated with bis(2-chloroethyl) ether effluent concentration. ^

Functional analysis of the sea urchin {\it orthodenticle\/} -related gene, {\it SPOTX\/}, in aboral ectoderm-specific gene activation and aboral ectoderm cell fate specification

An important question in developmental biology is how embryonic cell types are derived from a fertilized egg. To address this question, this thesis investigates the mechanisms by which the aboral ectoderm-specific Spec2a gene is spatially and temporally regulated during sea urchin embryogenesis. The Spec2a gene of the sea urchin Strongylocentratus purpuratus has served as a valuable maker to understand the basis of lineage-specific gene activation and the role of transcription factors in cell fate specification. The hypothesis is that transcription factors responsible for cell type-specific gene activation are key components in the initial cell specification step. The Spec2a gene, which encodes a small cytosolic calcium-binding protein, is expressed exclusively in aboral ectoderm cell lineages. The 1516-bp control region of the Spec2a gene contains a 188-bp enhancer element required for temporal activation and aboral ectoderm/mesenchyme cell expression, while an unidentified element upstream of the enhancer represses expression in mesenchyme cells. Using an enhancer activation assay, combined with site-directed mutagenesis, I showed that three TAATCC/T sites within the enhancer are responsible for enhancer activity. Mutagenizing these sites and a fourth one just upstream abolished all activity from the Spec2a control region. A 77-bp DNA fragment from the Spec2a enhancer containing two of the TAATCC/T sites is sufficient for aboral ectoderm/mesenchyme cell expression. A cDNA encoding SpOtx, an orthodenticle-related protein, was cloned from S. purpuratus and shown to bind with high affinity to the TAATCC/T sequences within the Spec2a control region. SpOtx transcripts were found initially in all cells of the cleaving embryo, but they gradually became restricted to oral ectoderm and endoderm cells, suggesting that SpOtx might play a role in the initial temporal activation of the Spec2a gene and most likely has additional functions in the developing embryo. To reveal the broader biological functions of SpOtx, I injected SpOtx mRNA into living sea urchin eggs to determine what effects overexpressing the SpOtx protein might have on embryo development. SpOtx mRNA-injected embryos displayed dramatic alterations in development. Instead of developing into pluteus larvae with 15 different cell types, uniform epithelia balls were formed. These balls consisted of a thin layer of squamous cells with short cilia highly reminiscent of aboral ectoderm. Immunohistochemical staining and RT-PCR demonstrated that the SpOtx-injected embryoids expressed aboral ectoderm markers uniformly, but showed very weak or no expression of markers for non-aboral ectoderm cell types. These data strongly suggested that overexpression of SpOtx redirected the normal fate of non-aboral ectoderm cells to that of aboral ectoderm. These results show that SpOtx is involved in aboral ectoderm differentiation by activating aboral ectoderm-specific genes and that modulating its expression can lead to changes in cell fate. ^

Integrated Data Sets of the EU FP5 Research Project ORFOIS: Origin and fate of biogenic particle fluxes in the ocean and their interactions with atmospheric CO2 concentrations as well as the marine sediment

For a reliable simulation of the time and space dependent CO2 redistribution between ocean and atmosphere an appropriate time dependent simulation of particle dynamics processes is essential but has not been carried out so far. The major difficulties were the lack of suitable modules for particle dynamics and early diagenesis (in order to close the carbon and nutrient budget) in ocean general circulation models, and the lack of an understanding of biogeochemical processes, such as the partial dissolution of calcareous particles in oversaturated water. The main target of ORFOIS was to fill in this gap in our knowledge and prediction capability infrastructure. This goal has been achieved step by step. At first comprehensive data bases (already existing data) of observations of relevance for the three major types of biogenic particles, organic carbon (POC), calcium carbonate (CaCO3), and biogenic silica (BSi or opal), as well as for refractory particles of terrestrial origin were collated and made publicly available.

Investigation of cell fate decision in Schizosaccharomyces pombe by ncRNA annotation and statistical analyses

Studies in the fission yeast Schizosaccharomyces pombe (S. pombe) have done much to inform the view of heterochromatin and its control by the RNA interference (RNAi) machinery. Using cDNA synthesised from poly(A)-enriched RNA samples, numerous novel ncRNA loci were discovered, and the 50 and 30 ends of many other genes were refined in previous studies. Although some of these transcripts may encode novel proteins the function of the majority is yet to be determined. The authors have used strand-specific deep sequencing of RNA, irrespective of poly(A) status, to reveal a highly structured antisense programme that modulates gene expression to dictate cell fate decisions during sexual differentiation. They show that an extensive and elaborate array of ncRNA production accompanies sexual differentiation in the fission yeast S. pombe. Experimental manipulation suggests that these transcripts specifically regulate the function of the target genes.

Regulated expression of P210 Bcr-Abl during embryonic stem cell differentiation stimulates multipotential progenitor expansion and myeloid cell fate

P210 Bcr-Abl is an activated tyrosine kinase oncogene encoded by the Philadelphia chromosome associated with human chronic myelogenous leukemia (CML). The disease represents a clonal disorder arising in the pluripotent hematopoietic stem cell. During the chronic phase, patients present with a dramatic expansion of myeloid cells and a mild anemia. Retroviral gene transfer and transgenic expression in rodents have demonstrated the ability of Bcr-Abl to induce various types of leukemia. However, study of human CML or rodent models has not determined the direct and immediate effects of Bcr-Abl on hematopoietic cells from those requiring secondary genetic or epigenetic changes selected during the pathogenic process. We utilized tetracycline-regulated expression of Bcr-Abl from a promoter engineered for robust expression in primitive stem cells through multilineage blood cell development in combination with the in vitro differentiation of embryonal stem cells into hematopoietic elements. Our results demonstrate that Bcr-Abl expression alone is sufficient to increase the number of multipotent and myeloid lineage committed progenitors in a dose-dependent manner while suppressing the development of committed erythroid progenitors. These effects are reversible upon extinguishing Bcr-Abl expression. These findings are consistent with Bcr-Abl being the sole genetic change needed for the establishment of the chronic phase of CML and provide a powerful system for the analysis of any genetic change that alters cell growth and lineage choices of the hematopoietic stem cell.

Regulation of dorsal fate in the neuraxis by Wnt-1 and Wnt-3a

Members of the Wnt family of signaling molecules are expressed differentially along the dorsal–ventral axis of the developing neural tube. Thus we asked whether Wnt factors are involved in patterning of the nervous system along this axis. We show that Wnt-1 and Wnt-3a, both of which are expressed in the dorsal portion of the neural tube, could synergize with the neural inducers noggin and chordin in Xenopus animal explants to generate the most dorsal neural structure, the neural crest, as determined by the expression of Krox-20, AP-2, and slug. Overexpression of Wnt-1 or Wnt-3a in the neuroectoderm of whole embryos led to a dramatic increase of slug and Krox-20-expressing cells, but the hindbrain expression of Krox-20 remained unaffected. Enlargement in the neural crest population could occur even when cell proliferation was inhibited. Wnt-5A and Wnt-8, neither of which is expressed in the dorsal neuroectoderm, failed to induce neural crest markers. Overexpression of glycogen synthase kinase 3, known to antagonize Wnt signaling, blocked the neural-crest-inducing activity of Wnt-3a in animal explants and inhibited neural crest formation in whole embryos. We suggest that Wnt-1 and Wnt-3a have a role in patterning the neural tube along its dorsoventral axis and function in the differentiation of the neural crest.

Neural fate of seen and unseen faces in visuospatial neglect: A combined event-related functional MRI and event-related potential study

To compare neural activity produced by visual events that escape or reach conscious awareness, we used event-related MRI and evoked potentials in a patient who had neglect and extinction after focal right parietal damage, but intact visual fields. This neurological disorder entails a loss of awareness for stimuli in the field contralateral to a brain lesion when stimuli are simultaneously presented on the ipsilateral side, even though early visual areas may be intact, and single contralateral stimuli may still be perceived. Functional MRI and event-related potential study were performed during a task where faces or shapes appeared in the right, left, or both fields. Unilateral stimuli produced normal responses in V1 and extrastriate areas. In bilateral events, left faces that were not perceived still activated right V1 and inferior temporal cortex and evoked nonsignificantly reduced N1 potentials, with preserved face-specific negative potentials at 170 ms. When left faces were perceived, the same stimuli produced greater activity in a distributed network of areas including right V1 and cuneus, bilateral fusiform gyri, and left parietal cortex. Also, effective connectivity between visual, parietal, and frontal areas increased during perception of faces. These results suggest that activity can occur in V1 and ventral temporal cortex without awareness, whereas coupling with dorsal parietal and frontal areas may be critical for such activity to afford conscious perception.