Novel regulators revealed by profiling Drosophila testis stem cells within their niche.

Stem cells are defined by the fact that they both self-renew, producing additional stem cells, and generate lineal descendants that differentiate into distinct functional cell types. In Drosophila, a small germline stem cell population is influenced by a complex microenvironment, the stem cell niche, which itself includes a somatic stem cell population. While stem cells are unique, their immediate descendants retain considerable stem cell character as they mitotically amplify prior to differentiation and can be induced to de-differentiate into stem cells.

Constitutive expression of a high-affinity sulfate transporter in Indian mustard affects metal tolerance and accumulation.

The Stylosanthes hamata SHST1 gene encodes a high-affinity sulfate transporter located in the plasma membrane. In this study the S. hamata SHST1 gene was constitutively expressed in Indian mustard [Brassica juncea (L.

Overexpressing both ATP sulfurylase and selenocysteine methyltransferase enhances selenium phytoremediation traits in Indian mustard.

A major goal of our selenium (Se) phytoremediation research is to use genetic engineering to develop fast-growing plants with an increased ability to tolerate, accumulate, and volatilize Se. To this end we incorporated a gene (encoding selenocysteine methyltransferase, SMT) from the Se hyperaccumulator, Astragalus bisulcatus, into Indian mustard (LeDuc, D.L.

Study of phytochelatins and other related thiols as complexing biomolecules of As and Cd in wild type and genetically modified Brassica juncea plants.

The accumulation of As and Cd in Brassica juncea plants and the formation of complexes of these elements with bioligands such as glutathione and/or phytochelatins (PCs) is studied. The genetic manipulation of these plants to induce higher As and Cd accumulation has been achieved by overexpressing the genes encoding for gamma-glutamyl cysteine synthetase (gamma-ECS) and glutathione synthetase (GS). These two enzymes are responsible for glutathione (GSH) formation in plants, which is the first step in the production of PCs.

Selenium volatilization in vegetated agricultural drainage sediment from the San Luis Drain, Central California.

The presence of large amounts of Se-laden agricultural drainage sediment in the San Luis Drain, Central California, poses a serious toxic threat to wildlife in the surrounding environment. Effective management of the drainage sediment becomes a practical challenge because the sediment is polluted with high levels of Se, B, and salts. This two-year field study was conducted to identify the best plant species that are salt and B tolerant and that have a superior ability of volatilizing Se from drainage sediment.

Cell cycle kinetic dysregulation in HIV-infected normal lymphocytes.

Background: Viruses alter cellular gene transcription and protein binding at many steps critical for cell cycle regulation to optimize the milieu for productive infection. Reasoning that virus-host cell interactions would result in perturbations of cell cycle kinetics, measurement of the duration of the phases of the cell cycle in normal T lymphocytes infected with human immunodeficiency virus (HIV) was undertaken.

Methods: Flow cytometric measurement of bromodeoxyuridine-labeled and DNA content-stained cells at multiple points through the cell cycle allowed estimation of the fraction of cells in each phase, the potential doubling-time, and the durations of S and G(2)/M phases.

Estimating cell death in G(2)M using bivariate BrdUrd/DNA flow cytometry.

Background: In an accompanying paper (Asmuth et al.) it was found necessary to include cell death explicitly to estimate parameters of cell proliferation. The use of bivariate flow cytometry to estimate the phase durations and the doubling times of cells labeled with thymidine analogues is well established.

Phytoremediation of toxic trace elements in soil and water.

Toxic heavy metals and metalloids, such as cadmium, lead, mercury, arsenic, and selenium, are constantly released into the environment. There is an urgent need to develop low-cost, effective, and sustainable methods for their removal or detoxification. Plant-based approaches, such as phytoremediation, are relatively inexpensive since they are performed in situ and are solar-driven.

The emergence of national electronic health record architectures in the United States and Australia: models, costs, and questions.

Emerging electronic health record models present numerous challenges to health care systems, physicians, and regulators. This article provides explanation of some of the reasons driving the development of the electronic health record, describes two national electronic health record models (currently developing in the United States and Australia) and one distributed, personal model. The US and Australian models are contrasted in their different architectures ("pull" versus "push") and their different approaches to patient autonomy, privacy, and confidentiality.

Field trial of transgenic Indian mustard plants shows enhanced phytoremediation of selenium-contaminated sediment.

Three transgenic Indian mustard [Brassica juncea (L.) Czern.] lines were tested under field conditions for their ability to remove selenium (Se) from Se- and boron-contaminated saline sediment.

Elimination of the differential chemoresistance between the murine B-cell lymphoma LY-ar and LY-as cell lines after arsenic (As2O3) exposure via the overexpression of gsto1 (p28).

Purpose: Arsenic, in the form of As(2)O(3), has gained therapeutic importance because it has been shown to be very effective clinically in the treatment of acute promyelocytic leukemia (APL). Via numerous pathways arsenic induces cellular alterations such as induction of apoptosis, inhibition of cellular proliferation, stimulation of differentiation, and inhibition of angiogenesis. Responses vary depending on cell type, dose and the form of arsenic.

Speciation of volatile selenium species in plants using gas chromatography/inductively coupled plasma mass spectrometry.

Gas chromatography/inductively coupled plasma mass spectrometry (GC/ICP-MS) coupled with solid phase micro-extraction can provide a simple, extremely selective and sensitive technique for the analysis of volatile sulfur and selenium compounds in the headspace of growing plants. In this work, the technique was used to evaluate the volatilization of selenium in wild-type and genetically-modified Brassica juncea seedlings. By converting toxic inorganic selenium in the soil to less toxic, volatile organic selenium, B.

Mixed messages: legal incentives and disincentives confronting technologically mediated care.

The "systems" approach to reducing medical errors is increasingly viewed as dependent upon technology. Issues with the legal system, however, may impede needed reforms. Historically there has been a pervasive disconnect between the legal system and changes in healthcare business models and structures.

Electronic health records: international, structural and legal perspectives.

The EHR is a database record that incorporates a patient's health care details from conception to death and which can be distributed over a number of sites or aggregated at a particular source. This article describes the function and concept of the EHR by relating it to other medical information technologies, parallel changes in health care delivery, and a holistic health information model. The article compares the progress that Europe, Australia and the United States have made in the journey towards EHR implementation and concludes by highlighting some of the costs, barriers and consequences associated with the transition to a comprehensive EHR system.

Exploring the selenium phytoremediation potential of transgenic Indian mustard overexpressing ATP sulfurylase or cystathionine-gamma-synthase.

Indian mustard (Brassica juncea) plants overexpressing ATP sulfurylase (APS transgenics) were previously shown to have higher shoot selenium (Se) levels and enhanced Se tolerance compared to wild type when supplied with selenate in a hydroponic system. Other transgenic Indian mustard overexpressing cystathionine-gamma-synthase (CGS) showed a higher Se volatilization rate, lower shoot Se levels, and higher Se tolerance than wild type, also in hydroponic studies. In the present study, these APS and CGS transgenics were evaluated for their capacity to accumulate Se from soil that is naturally rich in Se.

SELENIUM IN HIGHER PLANTS.

Plants vary considerably in their physiological response to selenium (Se). Some plant species growing on seleniferous soils are Se tolerant and accumulate very high concentrations of Se (Se accumulators), but most plants are Se nonaccumulators and are Se-sensitive. This review summarizes knowledge of the physiology and biochemistry of both types of plants, particularly with regard to Se uptake and transport, biochemical pathways of assimilation, volatilization and incorporation into proteins, and mechanisms of toxicity and tolerance.

Overexpression of ATP sulfurylase in Indian mustard: effects on tolerance and accumulation of twelve metals.

Indian mustard [Brassica juncea (L.) Czern.] transgenics overexpressing ATP sulfurylase (APS plants) were shown previously to have higher levels of total thiols, S, and Se.

Identification and characterization of Se-methyl selenomethionine in Brassica juncea roots.

The present work shows the identification and characterization of Se-methyl selenomethionine (SeMMet) as an important Se species in Brassica juncea roots when grown in the presence of Se-methionine (SeMet) as the Se source. SeMMet was isolated by liquid chromatography employing two different liquid chromatographic mechanisms: reversed-phase ion-pairing using heptafluorobutyric acid as counter ion and cation exchange using a pyridinium formate gradient (pH 3). Inductively coupled plasma mass spectrometry was used for the detection of Se.

Cellular kinetics of murine lung: model system to determine basis for radioprotection with keratinocyte growth factor.

Purpose: Normal tissue toxicity remains a dose limitation for cancer radiotherapy and chemoradiotherapy. Growth factors offer a novel means of mitigating normal tissue radiotoxicity. In particular, keratinocyte growth factor (rHuKGF), whose proliferative activity is restricted to epithelial cells, holds promise on the basis of the findings of preclinical models of epithelial cytoprotection and the clinical developments to date.

Overexpression of selenocysteine methyltransferase in Arabidopsis and Indian mustard increases selenium tolerance and accumulation.

A major goal of phytoremediation is to transform fast-growing plants with genes from plant species that hyperaccumulate toxic trace elements. We overexpressed the gene encoding selenocysteine methyltransferase (SMT) from the selenium (Se) hyperaccumulator Astragalus bisulcatus in Arabidopsis and Indian mustard (Brassica juncea). SMT detoxifies selenocysteine by methylating it to methylselenocysteine, a nonprotein amino acid, thereby diminishing the toxic misincorporation of Se into protein.

Overexpression of cystathionine-gamma-synthase enhances selenium volatilization in Brassica juncea.

Selenium (Se) can be assimilated and volatilized via the sulfate assimilation pathway. Cystathionine-gamma-synthase (CGS) is thought to catalyze the synthesis of Se-cystathionine from Se-cysteine, the first step in the conversion of Se-cysteine to volatile dimethylselenide. Here the hypothesis was tested that CGS is a rate-limiting enzyme for Se volatilization.

Modulating effect of keratinocyte growth factor on cellular kinetics of murine lung(I).

Background & Objective: Keratinocyte growth factor (KGF) causes the proliferation of type II pneumocytes in the lungs and confers protection against many external stimulation in the lung. Historically, the kinetic parameters, especially of slowly proliferating normal tissues, such as the lung, were difficult to measure. However, recently developed techniques made it possible to measure accurately the cellular kinetics in normal tissues.