Effect of Chlorpyrifos on Efflux Transporter Gene Expression and Function in Caco-2 Cells

The effect of chlorpyrifos (CPF) and its metabolite, chlorpyrifos-oxon (CPO), on multidrug resistance-1 (MDR1) gene expression and efflux transporter function in Caco-2 cells was determined. The effect of CPF and CPO on gene expression in Caco-2 cells was tested as a function of time using RT-PCR and competitive PCR (compPCR) techniques. The RT-PCR results depicted a maximal effect of CPF exposure on MDR1 expression at 8 h, which decreased at 24 h. Studies with CPO displayed an initial increase in expression at 4 h only. The compPCR assays were conducted with the CPF-treated group to quantify the changes in gene expression levels. The compPCR data confirmed and quantitated the results from the time-course study using semiquantitative RT-PCR. In addition to the gene expression studies, changes in efflux transporter function were investigated using Caco-2 cells grown on semipermeable membranes in Transwell plates. The permeability of verapamil was determined in cells treated for 8 h with CPF. Efflux ratios demonstrated that verapamil was effluxed at a higher rate from the CPF-treated cells as compared to the control group, confirming the inductive action of CPF on transporter function. These results suggest that CPF has the potential to modulate the bioavailability of drugs via changes in expression and function of membrane efflux transporters.

An autosomal genome scan for loci influencing longitudinal burden of body mass index from childhood to young adulthood in white sibships: The Bogalusa Heart Study

OBJECTIVE

To examine genetic loci linked to a long-term burden and trend of obesity traits, such as body mass index (BMI), from childhood to adulthood.

DESIGN

: Longitudinal study using serial measurements of BMI from childhood.

SUBJECTS

A total of 782 unselected white siblings (representing 521 full and 39 half sib-pairs) from 342 families enrolled in the Bogalusa Heart Study.

MEASUREMENTS

A total of 357 microsatellite markers with an average spacing of 9.0 cM spanning the 22 autosomal chromosomes were typed. A quadratic growth curve was developed using a random effects model based on serial measurements of BMI from childhood to adulthood. The serial changes in BMI were measured in terms of long-term burden (area under the curve (AUC) divided by follow-up years) and the long-term trend (incremental AUC, calculated as total AUC-baseline AUC).

RESULTS

Heritability estimates of long-term measures were 0.78 for total AUC and 0.43 for incremental AUC. In a variance-component-based multipoint linkage analysis with SOLAR, linkage to the long-term measures of BMI was observed on chromosomes 1, 5, 7, 12, 13 and 18. For total AUC, LOD scores were 3.0 at 110 cM on chromosome 12, 2.9 at 26 cM and 2.4 at 52 cM on chromosome 7, and 2.2 at 126 cM on chromosome 5. For incremental AUC, LOD scores were 2.9 at 26 cM, 2.1 at 97 cM and 2.3 at 110 cM on chromosome 12, 2.2 at 69 cM on chromosome 7, 2.2 at 91 cM and 2.5 at 150 cM on chromosome 1, 2.0 at 119 cM on chromosome 5, 2.0 at 54 cM on chromosome 13 and 2.0 at 7 cM on chromosome 18. Several important obesity-related candidate genes are located in the regions or near the markers showing positive linkage.

CONCLUSION

Linkage evidence found in this study indicates that regions on these chromosomes might harbor genetic loci that affect the propensity to develop obesity from childhood.

Infusion of in vitro-generated DN T regulatory cells induces permanent cardiac allograft survival in mice

Previously, we have demonstrated that pretransplant donor lymphocyte infusion (DLI) can activate recipient-derived CD3+CD4-CD8- double negative T regulatory (DN Tr) cells which have a potent immune regulatory function in vitro and in vivo. Here we studied the regulatory ability of DN T cell clones generated from the spleens of nai;ve anti-L(d) transgenic TCR+ (2C x dm2)F1 mice. We were able to identify subsets of DN T cell clones that were able to kill anti-Ld CD8+ T cells, and therefore had regulatory properties, and DN T cells with no regulatory properties. Next, we investigated the ability of these in vitro generated DN T cell clones to enhance cardiac allograft survival. (2C x dm2)F1 transgenic mice were infused with either regulatory or non-regulatory DN T cell clones, or left untreated one day before receiving an Ld-mismatched cardiac grafts from (C57BL/6 x Balb/c)F1 mice. Injection of non-regulatory DN T clone cells did not prolong cardiac graft survival in (2C x dm2)F1 mice when compare to untreated controls. In contrast, all of the cardiac grafts survived more than 100 days in mice that received DN Tr clone cells prior to transplantation. These results demonstrate that DN Tr cells can be generated in vitro and protect cardiac allograft from rejection when infused into recipients prior to transplantation. They also suggest that DN Tr cells may provide a novel therapy for the treatment of allograft rejection.

Upgrading of existing sludge treatment processes for phosphorus management serving a EBPR WWTP

For a large-scale wastewater treatment plant to comply with phosphorus consents using enhanced biological phosphorus removal processes, its sludge and liquor treatment processes need to be carefully upgraded. In this case study, the wastewater treatment plant of interest has three different types of sludge treated by two different and independent sludge treatment processes. The task of upgrading the sludge treatment systems to serve an EBPR process while satisfying other regulatory and operational constraints in a cost effective way presents an interesting challenge. A range of process options was investigated to include P-rich surplus activated sludge treatment, raw sludge treatment, and sludge liquors treatment. Sludge pre-liming, i.e. to introduce lime slurry into raw liquid sludge before the dewatering stage, was studied in bench-scale and full-scale trials for phosphorus precipitation and pathogen reduction. It was applied to the mixture of surplus activated sludge and imported sludge. The results showed that a complete phosphorus precipitation was achieved at above pH 9 with lime addition of 7% (w/w as calcium hydroxide to sludge dry weight). A satisfactory 2-log pathogen reduction was consistently achieved at above pH 11 with lime addition of 14% (w/w). The process significantly simplified the potential upgrading work for sludge and liquor treatment, compared to other alternatives.

Sensitivity of the ultrasonic CARI technique for breast tumor detection using a FETD scheme

The CARI (clinical amplitude/velocity reconstruction imaging) technique is a new ultrasonography for better detection of the breast cancer. The method uses the mammography-like positioning of the breast and a reference structure to assess the changes of sound velocity in the screened region. In this work, we present a first attempt to simulate the CARI technique using finite element time-domain (FETD) wave propagation. The CARI sensitivity to the size, shape and location of the tumors is investigated via the simulations on 2D and 3D breast models. Small lesions can be detectable under a suitable spatial resolution. 3D simulations agree with the quantitative results of the 2D case. Moreover, the FETD approximation is proving to be a simple, but robust tool in the CARI simulation.

Fractional Laplacian time-space models for linear and nonlinear lossy media exhibiting arbitrary frequency power-law dependency

Frequency-dependent attenuation typically obeys an empirical power law with an exponent ranging from 0 to 2. The standard time-domain partial differential equation models can describe merely two extreme cases of frequency-independent and frequency-squared dependent attenuations. The otherwise nonzero and nonsquare frequency dependency occurring in many cases of practical interest is thus often called the anomalous attenuation. In this study, a linear integro-differential equation wave model was developed for the anomalous attenuation by using the space-fractional Laplacian operation, and the strategy is then extended to the nonlinear Burgers equation. A new definition of the fractional Laplacian is also introduced which naturally includes the boundary conditions and has inherent regularization to ease the hypersingularity in the conventional fractional Laplacian. Under the Szabo's smallness approximation, where attenuation is assumed to be much smaller than the wave number, the linear model is found consistent with arbitrary frequency power-law dependency.

Key influential factors for sludge pre-fermentation process design--a case study

Sewage sludge pre-fermentation process produces readily biodegradable carbon, which is essential for reliable biological phosphorus removal and efficient denitrification. This bench scale study was to develop site-specific design parameters for a sludge fermentation process, and to look into the effects of various influential factors. The key factors investigated induded solids retention time (4-8 days), temperature (9-19 degrees C) and sludge concentrations (0.5%-4% DS). The optimum Volatile Fatty Adds yield was found at a sludge concentration of 1%-1.5% DS. A solid retention time of 4 days at 15-20 degrees C was found to be most cost effective. The fermentation reaction was temperature sensitive, which was found to be inefficient at temperature below 12-15 degrees C. Under the optimum conditions, 80-100 mgVFA g(-1) VSS can be generated from fermentation process, which will result in an increase of 20-24 mg l(-1) in the settled sewage based on average flow. A significant pathogen reduction level was also demonstrated over the fermentation period. Liquid sludge from the small rural wastewater treatment plants is often imported to a regional sludge treatment centre for more advanced treatment to comply with the Regulations. The suitability of this imported sludge for pre-fermentation process was also investigated in this study.

No evidence for links between autism, MMR and measles virus

BACKGROUND

We examined whether, in the UK, there is an increased risk of autism (AD) following exposures, in early life, to: (1) wild measles; (2) live attenuated measles, alone or in combination as MMR; and (3) the alteration of the mumps strain within MMR.

METHOD

We conducted time trend analyses of 2407 AD subjects born between 1959-93; and for comparison, 4640 Down's syndrome (DS) subjects born between 1966-93. Between 1968-86, we correlated variations in AD and DS births with wild measles incidence. Between 1959-93, we tested for abrupt changes in the long-term AD birth trend for the effects of introducing: (1) monovalent measles vaccines in 1968; (2) MMR immunization in 1988; and (3) the 'overnight switch' from mixed use of Urabe MMR to exclusive use of Jeryl-Lynn MMR in 1992. Incidence rate ratios (IRRs) were used as measures of association.

RESULTS

We found no significant association between AD births and exposure (prenatal and postnatal up to 18 months age) to population rates of measles infections, and no 'step-up' increase in AD births associated with the introduction of monovalent measles and MMR vaccines, and changing mumps strain. An unexpected reduction in AD births of 21% (95% CI 6.9-33.3%; P=0.005) among the post-1987 birth cohorts was detected.

CONCLUSION

No increased risk of AD following exposures to wild measles and vaccinations with monovalent measles, and Urabe or Jeryl-Lynn variants of MMR was detected. The precise meaning of the detected AD births reduction is unclear. Our study cannot exclude rare complications of MMR, given its correlational design.

Arginine stimulates intestinal cell migration through a focal adhesion kinase dependent mechanism

BACKGROUND

L-Arginine is a nutritional supplement that may be useful for promoting intestinal repair. Arginine is metabolised by the oxidative deiminase pathway to form nitric oxide (NO) and by the arginase pathway to yield ornithine and polyamines.

AIMS

To determine if arginine stimulates restitution via activation of NO synthesis and/or polyamine synthesis.

METHODS

We determined the effects of arginine on cultured intestinal cell migration, NO production, polyamine levels, and activation of focal adhesion kinase, a key mediator of cell migration.

RESULTS

Arginine increased the rate of cell migration in a dose dependent biphasic manner, and was additive with bovine serum concentrate (BSC). Arginine and an NO donor activated focal adhesion kinase (a tyrosine kinase which localises to cell matrix contacts and mediates beta1 integrin signalling) after wounding. Arginine stimulated cell migration was dependent on focal adhesion kinase (FAK) signalling, as demonstrated using adenovirus mediated transfection with a kinase negative mutant of FAK. Arginine stimulated migration was dependent on NO production and was blocked by NO synthase inhibitors. Arginine dependent migration required synthesis of polyamines but elevating extracellular arginine concentration above 0.4 mM did not enhance cellular polyamine levels.

CONCLUSIONS

These results showed that L-arginine stimulates cell migration through NO and FAK dependent pathways and that combination therapy with arginine and BSC may enhance intestinal restitution via separate and convergent pathways.

First Report of Pythium irregulare on Lentils in the United States

In late June and early July 2002, stunted, chlorotic, and partially defoliated lentils (Lens culinaris Medik.) were observed throughout the lentil-growing areas of eastern Washington. These symptoms were investigated in two fields near Garfield, WA and one field near Genesee, ID. Cv. Mason was more affected than cv. Brewer. Roots were dry and brittle with black discoloration in some cases. Isolates of Fusarium oxysporum and F. solani were obtained from washed roots plated on water agar, but they were nonpathogenic in greenhouse testing in pasteurized field soil and peat-based growing mixes. On 21 April 2003, volunteer lentils growing in the same fields showed symptoms of root rot, and Pythium oospores were observed in the roots. Pythium spp. were isolated by using a selective medium (2). Oospores were aplerotic, intercalary, 12.6 to 21 μm long × 11.2 to 18.2 μm wide, mostly smooth, and often formed in chains. Isolates resembled P. paroecandrum Drechs. and P. irregulare Buisman on the basis of morphological characters (3), but DNA sequences of the internal transcribed spacer region were closer to P. irregulare on the basis of a comparison with a worldwide database of Pythium sequences (C. A. Lévesque, personal communication). Isolates were deposited with the USDA-ARS Western Regional Plant Introduction Station, Pullman, WA. Four hyphal-tip isolates were tested in the greenhouse with inoculum grown in autoclaved sandy loam amended with 1% ground rolled oats. Experiments were performed twice in Thatuna silt loam, first in pasteurized and then in nonpasteurized soil. Inoculum was added to the soil at 500 CFU/g, and seeds were planted on the same day. Each isolate was tested on cvs. Brewer and Mason, with five replicates per treatment. Plants were grown in 4- × 20.5-cm plastic tubes (two plants per tube) for 1 month at 16 to 22°C and supplemented with 14 h of light per day. P. irregulare was reisolated from infected roots in both experiments. Damping-off, stunting, chlorosis, and root rot were observed in the Pythium-inoculated treatments, which corresponded to symptoms observed in the field in 2002. In pasteurized soil, only one isolate reduced the whole, dry, plant weight of Brewer, but the other three isolates reduced the dry weight of Mason. All isolates reduced the root dry weight of Mason in natural soil, but only two isolates reduced the root dry weight of Brewer. To our knowledge, Pythium spp., but not P. irregulare, have been reported previously from lentils (1). P. irregulare also causes root rot on winter wheat, which is rotated with lentils, and this pathogen likely causes yield reduction in both crops. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) S. M. Mircetich and J. M. Kraft. Mycopathol. Mycol. Appl. 50:151, 1973. (3) A. J. van der Plaats-Niterink. Stud. Mycol. 21:1, 1981.

The Discriminative Stimulus Effects of γ-Hydroxybutyrate and Related Compounds in Rats Discriminating Baclofen or Diazepam: The Role of GABAB and GABAA Receptors

The discriminative stimulus effects of gamma-hydroxybutyrate (GHB) can be mimicked by GABA(A) receptor-positive modulators (e.g., diazepam) and GABA(B) receptor agonists (e.g., baclofen). The purposes of this study were to see whether stimulus control could be established with baclofen and to further characterize the role of GABAergic mechanisms in the behavioral actions of GHB by evaluating GHB and related compounds in rats discriminating either diazepam or baclofen. Training criteria were satisfied with baclofen and diazepam after 69 and 44 sessions, respectively. GHB and its precursors gamma-butyrolactone and 1,4-butanediol occasioned >80% responding on the drug-associated lever in rats discriminating baclofen and <11% in rats discriminating diazepam. Diazepam and other GABA(A) receptor-positive modulators occasioned intermediate levels of responding on the baclofen lever, whereas baclofen occasioned less than 4% responding on the diazepam lever. The GABA(B) receptor antagonist CGP 35348 [(3-aminopropyl)(diethoxymethyl) phosphinic acid] partially antagonized the effects of baclofen as well as the baclofen-like effects of GHB, and flumazenil partially antagonized the effects of diazepam. This study established stimulus control with baclofen, and substitution data provided direct evidence for a role of GABAergic, especially GABA(B), mechanisms in the discriminative stimulus effects of GHB. The lack of substitution by GHB or its metabolic precursors for diazepam indicates a comparatively smaller role of GABA(A) mechanisms in these effects of GHB. The inability of CGP 35348 to completely attenuate the effects of baclofen and GHB suggests that multiple receptors could be involved in the discriminative stimulus effects of GHB.

Glucocorticosteroids for primary sclerosing cholangitis

BACKGROUND

Glucocorticosteroids have been suggested for primary sclerosing cholangitis, which is characterised by chronic inflammation and fibrosis in the intrahepatic and extrahepatic biliary tree.

OBJECTIVES

To assess the beneficial and harmful effects of glucocorticosteroids for patients with primary sclerosing cholangitis.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials on The Cochrane Library, MEDLINE, EMBASE from their inception until March 2003, and reference lists.

SELECTION CRITERIA

Randomised clinical trials comparing any dose or duration of glucocorticosteroids versus placebo, no intervention, or other immunosuppressive agents. We included trials irrespective of language, blinding, or publication status.

DATA COLLECTION AND ANALYSIS

Both reviewers extracted data independently and assessed the methodological quality by the generation of the allocation sequence, allocation concealment, double blinding, and follow-up. The results of the meta-analyses were presented as relative risks or weighted mean difference (WMD), both with 95% confidence intervals (CI). The primary outcome measures were mortality and liver-related morbidity.

MAIN RESULTS

Two randomised clinical trials were eligible for inclusion. One trial compared biliary lavage with hydrocortisone versus saline in 17 patients. A significant number of adverse events (pancreatitis; cholangitis with septicaemia; paranoid ideas; fluid retention) and no cholangiographic improvement led to termination of the trial. The other trial compared budesonide versus prednisone in 18 patients. Patients had significantly higher serum bilirubin concentration after treatment with prednisone compared with budesonide (WMD 10.4 micro mol/litre, 95% CI 1.16 to 19.64 micro mol/litre). No other significant effects on clinical or biochemical outcomes were identified for any of the evaluated interventions.

REVIEWERS' CONCLUSIONS

There is no evidence to support or refute peroral glucocorticosteroids for patients with primary sclerosing cholangitis.

Aldosterone signaling modifies capillary formation by human bone marrow endothelial cells

We investigated the regulation of the epithelial sodium channel (ENaC) in human bone marrow endothelial cells (HBMEC) responding to mineralocorticoid hormones and other accessory effectors. The message for both the mineralocorticoid receptor (MCR) and the alpha subunit of ENaC was expressed in HBMEC as predicted bands of 838 and 521 bp, respectively. In Western blots, the MCR of about 107 kDa was localized primarily in the cytoplasmic compartment but migrated to the nucleus when cell cultures were exposed to exogenous aldosterone. On the other hand, the alphaENaC was revealed as a membrane-bound protein of approximately 82 kDa, whose abundance increased after aldosterone treatment. Confocal microscopy confirmed the presence of both the MCR and ENaC as nucleocytoplasmic and membrane-bound proteins, respectively, and both colocalized with tubulin in situ. On Matrigel, the mineralocorticoid aldosterone, by itself, did not influence capillary formation by HBMEC, but the diuretic amiloride reduced the organization of HBMEC into capillary-like networks; curiously, aldosterone further exacerbated this inhibitory effect of amiloride. On the fibrin matrix, aldosterone had no influence at all on the length of the newly formed capillaries, but the capillary diameter was highly increased over the control. Aldosterone-mediated capillary swelling was totally reversed by amiloride, which, by itself, also inhibited capillary elongation by HBMEC. Thus, cell signaling by mineralocorticoid hormones in HBMEC appears to proceed in a manner very similar to that in the epithelial cell, thereby leading to an increase in the endothelial cell volume, which may underline the hypertensive state and which may also modify angiogenesis.