Low density polyethylene (LDPE) passive samplers for the investigation of polychlorinated biphenyl (PCB) point sources in rivers

This study aims to provide a passive sampling approach which can be routinely used to investigate polychlorinated biphenyl (PCB) sources in rivers. The approach consists of deploying low density polyethylene (LDPE) strips downstream and upstream of potential PCB sources as well as in their water discharges. Concentrations of indicator PCBs (iPCBs) absorbed in samplers (Cs) from upstream and downstream sites are compared with each other to reveal increases of PCB levels. Cs measured in water discharges are used to determine if released amounts of PCBs are compatible with increases revealed in the river. As water velocity can greatly vary along a river stretch and influences the uptake at each site in a different way, differences in velocity have to be taken into account to correctly interpret Cs. LDPE strips were exposed to velocities between 1.6 and 37 cm s−1 using a channel system built in the field. Relationships between velocity and Cs were established for each iPCB to determine the expected change in Cs due to velocity variations. For PCBs 28 and 52, this change does not exceed a factor 2 for velocity variations in the range from 1.6 to 100 cm s−1 (extrapolated data above 37 cm s−1). For PCBs 101, 138, 153 and 180, this change only exceeds a factor 2 in the case of large velocity variations. The approach was applied in the Swiss river Venoge to first conduct a primary investigation of potential PCB sources and then conduct thorough investigations of two suspected sources.

Nuclear well logging in soils. Calibration of slim hole nuclear tools gamma-gamma and neutron-thermal neutron.

The calculation of elasticity parameters by sonic and ultra sonic wave propagation in saturated soils using Biot's theory needs the following variables : forpiation density and porosity (p, ø), compressional and shear wave velocities (Vp, Vs), fluid density, viscosity and compressibility (Pfi Ilfi Ki), matrix density and compressibility (p" K), The first four parameters can be determined in situ using logging probes. Because fluid and matrix characteristics are not modified during core extraction, they can be obtained through laboratory measurements. All parameters necessitate precise calibrations in various environments and for specific range of values encountered in soils. The slim diameter of boreholes in shallow geophysics and the high cost of petroleum equipment demand the use of specific probes, which usually only give qualitative results. The measurement 'of density is done with a gamma-gamma probe and the measurement of hydrogen index, in relation to porosity, by a neutron probe. The first step of this work has been carried out in synthetic formations in the laboratory using homogeneous media of known density and porosity. To establish borehole corrections different casings have been used. Finally a comparison between laboratory and in situ data in cored holes of known geometry and casing has been performed.

Fat poetry: a kingdom for PPAR gamma.

Adipose tissue is not an inert cell mass contributing only to the storage of fat, but a sophisticated ensemble of cellular components with highly specialized and complex functions. In addition to managing the most important energy reserve of the body, it secretes a multitude of soluble proteins called adipokines, which have beneficial or, alternatively, deleterious effects on the homeostasis of the whole body. The expression of these adipokines is an integrated response to various signals received from many organs, which depends heavily on the integrity and physiological status of the adipose tissue. One of the main regulators of gene expression in fat is the transcription factor peroxisome proliferator-activated receptor gamma (PPARgamma), which is a fatty acid- and eicosanoid-dependent nuclear receptor that plays key roles in the development and maintenance of the adipose tissue. Furthermore, synthetic PPARgamma agonists are therapeutic agents used in the treatment of type 2 diabetes.This review discusses recent knowledge on the link between fat physiology and metabolic diseases, and the roles of PPARgamma in this interplay via the regulation of lipid and glucose metabolism. Finally, we assess the putative benefits of targeting this nuclear receptor with still-to-be-identified highly selective PPARgamma modulators.

The murine interleukin-2 receptor gamma chain gene: organization, chromosomal localization and expression in the adult thymus.

Defects in the interleukin-2 receptor gamma (IL-2R gamma) chain in the man result in an X-linked severe combined immunodeficiency, SCIDX1, characterized by an absence of T-cell differentiation. This phenotype may result from pertubations in IL-2, IL-4-, IL-7- or IL-15-mediated signaling, as the IL-2R gamma chain forms an integral component of these receptor systems. We have isolated and characterized cDNA and genomic clones for the murine IL-2R gamma. The gene (Il2rg) is well conserved between mouse and man with respect to overall structure and size, and contains regions of high conservation in the promoter region as well. Il2rg maps to mouse X chromosome region 40, in a region of synteny with human Xq12-13.1. We have also explored the expression of the IL-2R gamma during thymocyte development. IL-2R gamma transcripts are detected in the earliest thymocyte precursor cells and persist throughout intrathymic development into the mature peripheral compartment. Genomic clones for the murine IL-2R gamma will allow for further studies on the regulation and function of this gene in vivo.

Role of high normal gamma-glutamyltransferase level in identifying heavy alcohol use in young men.

The objective of the current study was to determine the predictive value of high normal gamma-glutamyltransferase (GGT) level as an indication of heavy drinking in young men. In a sample of 577 men attending a one-day army recruitment process mandatory for all Swiss men at age 19 years, GGT level was evaluated as the dependent variable for each of eight dichotomous classifications of individuals on the basis of meeting cut-off criteria for five indexes of alcohol use, two indexes of alcohol-related problems, and one index of body mass. The sensitivity, specificity, and predictive values of GGT level in identifying subjects as either heavy drinkers or being overweight were determined. Compared with findings for their counterparts, GGT level was higher in subjects reporting consumption of more than 14 drinks per week (20.5 +/- 7.81 vs. 18.9 +/- 7.60, P <.05), in those reporting being drunk at least once during the past 30 days (20.3 +/- 7.80 vs. 18.3 +/- 7.43, P <.001), and in individuals with body mass indexes >or=25 kg/m(2) (25.8 +/- 10.84 vs. 18.3 +/- 6.59, P <.001). At a GGT level cut-off of 20 U/l, the sensitivity, specificity, and positive and negative predictive values of either being a heavy drinker or overweight were 48.2%, 70.2%, 67.7%, and 51.2%, respectively. Exclusion of subjects with body mass indexes of >or=25 kg/m(2) revealed similar results. High normal GGT level in young men is indicative of heavy alcohol use or being overweight; when present, subjects should be screened further for potential concomitant drinking problems.

Ex vivo analysis of human antigen-specific CD8+ T-cell responses: quality assessment of fluorescent HLA-A2 multimer and interferon-gamma ELISPOT assays for patient immune monitoring.

The authors developed a standardized approach for immune monitoring of antigen-specific CD8+ T cells within peripheral blood lymphocytes (PBLs) that combines direct ex vivo analysis of Melan-A/MART-1 and influenza-specific CD8+ T cells with HLA-A2/peptide multimers and interferon-gamma ELISPOT assays. Here the authors assessed the quality of results obtained with 180 PBLs from healthy donors and melanoma patients. Reproducibility of the multimer assay was good (average of 15% variation). In the absence of in vivo antigen-specific T-cell responses, physiologic fluctuations of multimer-positive T cells was low, with variation coefficients of 20% for Melan-A and 28% for influenza-specific T cells. In contrast, patients with vaccination-induced T-cell responses had significantly increased T-cell frequencies clearly exceeding physiologic fluctuations. Comparable results were obtained with ELISPOT assays. In conclusion, this approach is well suited to assess T-cell responses as biologic endpoints in clinical vaccine studies.

The optimal dividend barrier in the Gamma-Omega model

In the traditional actuarial risk model, if the surplus is negative, the company is ruined and has to go out of business. In this paper we distinguish between ruin (negative surplus) and bankruptcy (going out of business), where the probability of bankruptcy is a function of the level of negative surplus. The idea for this notion of bankruptcy comes from the observation that in some industries, companies can continue doing business even though they are technically ruined. Assuming that dividends can only be paid with a certain probability at each point of time, we derive closed-form formulas for the expected discounted dividends until bankruptcy under a barrier strategy. Subsequently, the optimal barrier is determined, and several explicit identities for the optimal value are found. The surplus process of the company is modeled by a Wiener process (Brownian motion).

FLIP prevents apoptosis induced by death receptors but not by perforin/granzyme B, chemotherapeutic drugs, and gamma irradiation.

FLICE-inhibitory protein, FLIP (Casper/I-FLICE/FLAME-1/CASH/CLARP/MRIT), which contains two death effector domains and an inactive caspase domain, binds to FADD and caspase-8, and thereby inhibits death receptor-mediated apoptosis. Here, we characterize the inhibitory effect of FLIP on a variety of apoptotic pathways. Human Jurkat T cells undergoing Fas ligand-mediated apoptosis in response to CD3 activation were completely resistant when transfected with FLIP. In contrast, the presence of FLIP did not affect apoptosis induced by granzyme B in combination with adenovirus or perforin. Moreover, the Fas ligand, but not the perforin/granzyme B-dependent lytic pathway of CTL, was inhibited by FLIP. Apoptosis mediated by chemotherapeutic drugs (i.e., doxorubicin, etoposide, and vincristine) and gamma irradiation was not affected by FLIP or the absence of Fas, indicating that these treatments can induce cell death in a Fas-independent and FLIP-insensitive manner.

Pretherapeutic gamma-glutamyltransferase is an independent prognostic factor for patients with renal cell carcinoma.

BACKGROUND: Gamma-glutamyltransferase (GGT) regulates apoptotic balance and promotes cancer progression and invasion. Higher pretherapeutic GGT serum levels have been associated with worse outcomes in various malignancies, but there are no data for renal cell carcinoma (RCC). METHODS: Pretherapeutic GGT serum levels and clinicopathological parameters were retrospectively evaluated in 921 consecutive RCC patients treated with nephrectomy at a single institution between 1998 and 2013. Gamma-glutamyltransferase was analysed as continuous and categorical variable. Associations with RCC-specific survival were assessed with Cox proportional hazards models. Discrimination was measured with the C-index. Decision-curve analysis was used to evaluate the clinical net benefit. The median postoperative follow-up was 45 months. RESULTS: Median pretherapeutic serum GGT level was 25 U l(-1). Gamma-glutamyltransferase levels increased with advancing T (P<0.001), N (P=0.006) and M stages (P<0.001), higher grades (P<0.001), and presence of tumour necrosis (P<0.001). An increase of GGT by 10 U l(-1) was associated with an increase in the risk of death from RCC by 4% (HR 1.04, P<0.001). Based on recursive partitioning-based survival tree analysis, we defined four prognostic categories of GGT: normal low (<17.5 U l(-1)), normal high (17.5 to <34.5 U l(-1)), elevated (34.5 to <181.5 U l(-1)), and highly elevated (⩾181.5 U l(-1)). In multivariable analyses that adjusted for the effect of standard features, both continuously and categorically coded GGT were independent prognostic factors. Adding GGT to a model that included standard features increased the discrimination by 0.9% to 1.8% and improved the clinical net benefit. CONCLUSIONS: Pretherapeutic serum GGT is a novel and independent prognostic factor for patients with RCC. Stratifying patients into prognostic subgroups according to GGT may be used for patient counselling, tailoring surveillance, individualised treatment planning, and clinical trial design.