Sorption and bioavailability of arsenic in selected Bangladesh soils.

The bioavailability of arsenic (As) in the soil environment is largely governed by its adsorption-desorption reactions with soil constituents. We have investigated the sorption-desorption behaviour of As in four typical Bangladeshi soils subjected to irrigation with As-contaminated groundwater. The total As content of soils (160 samples) from the Laksham district ranged from <0.

Derivation of contractile smooth muscle cells from embryonic stem cells.

Smooth muscle cells (SMCs) play a key role in vascular physiology and pathology. An appreciation of normal SMCs developmental mechanisms will likely lead to a better understanding of disease processes and potentially to novel treatment strategies. We present a method for generating relatively pure populations of SMCs from embryonic stem cells (ESC) which display appropriate excitation and contractile responses to vasoactive agonists.

Stability of titania nanoparticles in soil suspensions and transport in saturated homogeneous soil columns.

The stability of TiO(2) nanoparticles in soil suspensions and their transport behavior through saturated homogeneous soil columns were studied. The results showed that TiO(2) could remain suspended in soil suspensions even after settling for 10 days. The suspended TiO(2) contents in soil suspensions after 24h were positively correlated with the dissolved organic carbon and clay content of the soils, but were negatively correlated with ionic strength, pH and zeta potential.

Effects of copper, lead, and cadmium on the sorption and desorption of atrazine onto and from carbon nanotubes.

There are currently few studies on the dual effects of metal ions on the sorption of atrazine and conversely of atrazine on metal adsorption on multiwalled carbon nanotubes (MWCNTs). While a number of sorption models were considered to describe the sorption of atrazine on MWCNTs, the Polanyi-Manes model (PMM) fit the sorption isotherms well with the lowest mean weighted square errors. Atrazine was mainly adsorbed onto the surface and micropores of MWCNTs bundles or aggregates.

PDGF-DD, a novel mediator of smooth muscle cell phenotypic modulation, is upregulated in endothelial cells exposed to atherosclerosis-prone flow patterns.

Platelet-derived growth factor (PDGF)-BB is a well-known smooth muscle (SM) cell (SMC) phenotypic modulator that signals by binding to PDGF alphaalpha-, alphabeta-, and betabeta-membrane receptors. PDGF-DD is a recently identified PDGF family member, and its role in SMC phenotypic modulation is unknown. Here we demonstrate that PDGF-DD inhibited expression of multiple SMC genes, including SM alpha-actin and SM myosin heavy chain, and upregulated expression of the potent SMC differentiation repressor gene Kruppel-like factor-4 at the mRNA and protein levels.

The actin-associated protein Palladin is required for development of normal contractile properties of smooth muscle cells derived from embryoid bodies.

Palladin is a widely expressed actin-associated protein localized at stress fibers, focal adhesions, and other actin-based structures, playing a significant role in cell adhesion and cell motility. Knockout of Palladin in mice is embryonic lethal, demonstrating the importance of Palladin in development yet its role in the vasculature is not known. In the present study, smooth muscle cell (SMC) markers, such as myosin, actin, caldesmon, calponin, and LPP, were down-regulated in embryoid bodies (EBs) derived from embryonic stem cells lacking Palladin.

Kinetics and thermodynamics of sorption of nitroaromatic compounds to as-grown and oxidized multiwalled carbon nanotubes.

The sorption kinetics and thermodynamics of 1,3-dinitrobenzene (DNB), m-nitrotoluene (mNT), p-nitrophenol (pNP), and nitrobenzene (NB) on as-grown and nitric acid-oxidized multiwalled carbon nanotubes (MWCNTs) were investigated. The sorption kinetics was well described by a pseudo-second-order rate model, while both Langmuir and Freundlich models described the sorption isotherms well and the sorption thermodynamic parameters of equilibrium constant (K(0)), standard free energy (DeltaG), standard enthalpy (DeltaH), and standard entropy changes (DeltaS) were measured. The values of DeltaH and DeltaG suggested that the sorption of nitroaromatics (NACs) onto MWCNTs was exothermic and spontaneous.

PIAS1 mediates TGFbeta-induced SM alpha-actin gene expression through inhibition of KLF4 function-expression by protein sumoylation.

Objective: TGFbeta and proliferation/phenotypic switching of smooth muscle cells (SMCs) play a pivotal role in pathogenesis of atherosclerotic and restenotic lesions after angioplasty. We have previously shown that the protein inhibitor of activated STAT (PIAS)1 activates expression of SMC differentiation marker genes including smooth muscle (SM) alpha-actin by interacting with serum response factor (SRF) and class I bHLH proteins. Here, we tested the hypothesis that TGFbeta activates SM alpha-actin through PIAS1.

Speciation of metal-EDTA complexes by flow injection analysis with electrospray ionization mass spectrometry and ion chromatography with inductively coupled plasma mass spectrometry.

Flow injection analysis (FIA) with ESI-MS and ion chromatography (IC) with inductively coupled plasma-MS (ICP-MS) as the complementary technique have been explored for the determination of metal ions as their metal-EDTA complexes. ESI-MS enabled the identification of metal-EDTA complexes such as [Mn(EDTA)](2-), [Co(EDTA)](2-), [Ni(EDTA)](2-), [Cu(EDTA)](2-), [Zn(EDTA)](2-), [Pb(EDTA)](2-), and [Fe(EDTA)](1-) and their MS spectral showed that these metal-EDTA complexes were present in solution. Based on the ESI-MS, ion chromatographic separation and ICP-MS detection of these complexes are possible because IC-ICP-MS requires stable metal-EDTA complex during the chromatographic separation.

Sorption of anionic metsulfuron-methyl and cationic difenzoquat on peat and soil as affected by copper.

The effect of cationic copper (Cu2+) on the sorption of anionic metsulfuron-methyl (Me) and cationic difenzoquat (DZ) to peat and soil was studied using a batch equilibration method. The results showed that Cu2+ increased the sorption of Me but diminished the sorption of DZ. The adsorption of Cu2+ on the surface of peat and soil neutralizes the negative charge, making the zeta potential (zeta) of peat and soil less negative, consequently decreasing the repulsion between the surface of peat or soil and Me and increasing the sorption of Me.

Kruppel-like factor 4, Elk-1, and histone deacetylases cooperatively suppress smooth muscle cell differentiation markers in response to oxidized phospholipids.

Phenotypic switching of vascular smooth muscle cells (SMCs), such as increased proliferation, enhanced migration, and downregulation of SMC differentiation marker genes, is known to play a key role in the development of atherosclerosis. However, the factors and mechanisms controlling this process are not fully understood. We recently showed that oxidized phospholipids, including 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC), which accumulate in atherosclerotic lesions, are potent repressors of expression of SMC differentiation marker genes in cultured SMCs as well as in rat carotid arteries in vivo.

Sorption and desorption of phenanthrene onto iron, copper, and silicon dioxide nanoparticles.

The sorption and desorption of phenanthrene by three engineered nanoparticles including nanosize zerovalent iron (NZVI), copper (NZVC), and silicon dioxide (NSiO2) were investigated. The sorption of phenanthrene onto NSiO2 was linear and reversible due to the hydrophilic properties of NSiO2. In comparison, sorption of phenanthrene onto NZVI and NZVC was nonlinear and irreversible, which was potentially due to the existence of significantly heterogeneous surface energy distribution patterns detected by a standard molecular probe technique.

Dopamine inhibits mitochondrial motility in hippocampal neurons.

Background: The trafficking of mitochondria within neurons is a highly regulated process. In an earlier study, we found that serotonin (5-HT), acting through the 5-HT1A receptor subtype, promotes axonal transport of mitochondria in cultured hippocampal neurons by increasing Akt activity, and consequently decreasing glycogen synthase kinase (GSK3beta) activity. This finding suggests a critical role for neuromodulators in the regulation of mitochondrial trafficking in neurons.

The molecular basis of color vision in colorful fish: four long wave-sensitive (LWS) opsins in guppies (Poecilia reticulata) are defined by amino acid substitutions at key functional sites.

Background: Comparisons of functionally important changes at the molecular level in model systems have identified key adaptations driving isolation and speciation. In cichlids, for example, long wavelength-sensitive (LWS) opsins appear to play a role in mate choice and male color variation within and among species. To test the hypothesis that the evolution of elaborate coloration in male guppies (Poecilia reticulata) is also associated with opsin gene diversity, we sequenced long wavelength-sensitive (LWS) opsin genes in six species of the family Poeciliidae.

LEGO therapy and the social use of language programme: an evaluation of two social skills interventions for children with high functioning autism and Asperger Syndrome.

LEGO therapy and the Social Use of Language Programme (SULP) were evaluated as social skills interventions for 6-11 year olds with high functioning autism and Asperger Syndrome. Children were matched on CA, IQ, and autistic symptoms before being randomly assigned to LEGO or SULP. Therapy occurred for 1 h/week over 18 weeks.

CSF IgG heavy-chain bias in patients at the time of a clinically isolated syndrome.

Using FACS and single cell reverse transcriptase polymerase chain reaction, we examined the cerebrospinal fluid (CSF) IgG VH repertoires from 10 subjects with a clinically isolated demyelinating syndrome (CIS). B and plasma cell repertoires from individual subjects showed similar VH family germline usage, nearly identical levels of post-germinal center somatic hypermutation, and significant overlap in their clonal populations. Repertoires from 7 of 10 CIS subjects demonstrated a biased usage of VH4 and/or VH2 family gene segments in their plasma or B cell repertoires.

Sphingosine-1-phosphate receptor subtypes differentially regulate smooth muscle cell phenotype.

Objective: The role of sphingosine-1-phosphate (S1P) receptors in acute vascular injury and smooth muscle cell (SMC) phenotypic modulation is not completely resolved.

Methods And Results: S1P receptor antagonists were used to test the hypothesis that specific S1P receptor subtypes differentially regulate SMC phenotypic modulation. In response to acute balloon injury of the rat carotid artery, S1P1/S1P3 receptor mRNA levels were transiently increased at 48 hours whereas S1P2 receptor expression was decreased.

Gender differences in health care expenditures, resource utilization, and quality of care.

Background: Rising health care costs and quality of care concerns require a re-evaluation of various aspects of health care delivery. In order to properly manage costs, payers need to understand how different patient populations contribute to spending trends and where suboptimal quality of care is more prevalent, and, therefore, may drive cost trends.

Objective: To demonstrate significant opportunities for improvement in the management of postmenopausal women by highlighting areas of imbalance between health care costs and quality of care.

Orchid bees as bio-indicators for organic coffee farms in Costa Rica: does farm size affect their abundance?

The potential of Euglossini bees, especially Euglossa, as biological indicators of organic vs nonorganic coffee farms was studied in Atenas and San Isidro, Alajuela, Costa Rica using 1.8-cineole as lure. Observations were made for three days at each of four farms and complemented with data from a year of observations.

Conditional deletion of Krüppel-like factor 4 delays downregulation of smooth muscle cell differentiation markers but accelerates neointimal formation following vascular injury.

Phenotypic switching of smooth muscle cells (SMCs) plays a key role in vascular proliferative diseases. We previously showed that Krüppel-like factor 4 (Klf4) suppressed SMC differentiation markers in cultured SMCs. Here, we derive mice deficient for Klf4 by conditional gene ablation and analyze their vascular phenotype following carotid injury.

Pitx2 is functionally important in the early stages of vascular smooth muscle cell differentiation.

Mechanisms that control vascular smooth muscle cell (SMC) differentiation are poorly understood. We identify Pitx2 as a previously unknown homeodomain transcription factor that is rapidly induced in an in vitro model of SMC differentiation from multipotent stem cells. Pitx2 induces expression of multiple SMC differentiation marker genes by binding to a TAATC(C/T) cis-element, by interacting with serum response factor, and by increasing histone acetylation levels within the promoters of SMC differentiation marker genes.