Detection of estrogenic activity in sediment-associated compounds using in vitro reporter gene assays

Sediments may be the ultimate sink for persistent (xeno-)estrogenic compounds released into the aquatic environment. Sediment-associated estrogenic potency was measured with an estrogen receptor-mediated luciferase reporter gene (ER-CALUX) assay and compared with a recombinant yeast screen. The ER-CALUX assay was more sensitive to 17beta-estradiol (E2) than the recombinant yeast screen, with an EC50 of 6 pM E2 compared to 100 pM in the yeast screen. Yeast cells were unable to distinguish the anti-estrogens ICI 182,780 and (4-hydroxy)tamoxifen, which were agonistic in the yeast. Acetone-soluble fractions of hexane/acetone extracts of sediments showed higher estrogenic potency than hexane-soluble extracts in the ER-CALUX assay. Sediments obtained from industrialized areas such as the Port of Rotterdam showed the highest estrogenic potency of the 12 marine sediments tested (up to 40 pmol estradiol equivalents per gram sediment). The estrogenic activity of individual chemicals that can be found in sediments including: alkylphenol ethoxylates and carboxylates; phthalates; and pesticides, was tested. Increasing sidechain length of various nonylphenol ethoxylates resulted in decreased estrogenic activity. Of the phthalates tested, butylbenzylphthalate was the most estrogenic, though with a potency approximately 100,000 times less than E2. The organochlorine herbicides atrazine and simazine failed to induce reporter gene activity. As metabolic activation may be required to induce estrogenic activity, a metabolic transformation step was added to the ER-CALUX assay using incubation of compounds with liver microsomes obtained from PCB-treated rats. Results indicate that metabolites of E2, NP and bisphenol A were less active than the parent compounds, while metabolites of methoxychlor were more estrogenic following microsomal incubations.     

High-contrast fast Fourier transform acousto-optical tomography of phantom tissues with a frequency-chirp modulation of the ultrasound

We report new results on acousto-optical tomography in phantom tissues using a frequency chirp modulation and a CCD camera. This technique allows quick recording of three-dimensional images of the optical contrast with a two-dimensional scan of the ultrasound source in a plane perpendicular to the ultrasonic path. The entire optical contrast along the ultrasonic path is concurrently obtained from the capture of a film sequence at a rate of 200 Hz. This technique reduces the acquisition time, and it enhances the axial resolution and thus the contrast, which are usually poor owing to the large volume of interaction of the ultrasound perturbation.     

Remote sensing of sunlight-induced chlorophyll fluorescence and reflectance of Scots pine in the boreal forest during spring recovery

A measurement campaign to assess the feasibility of remote sensing of sunlight-induced chlorophyll fluorescence (ChlF) from a coniferous canopy was conducted in a boreal forest study site (Finland). A Passive Multi-wavelength Fluorescence Detector (PMFD) sensor, developed in the LURE laboratory, was used to obtain simultaneous measurements of ChlF in the oxygen absorption bands, at 687 and 760 nm, and a reflectance index, the PRI (Physiological Reflectance Index), for a month during spring recovery. When these data were compared with active fluorescence measurements performed on needles they revealed the same trend. During sunny days fluorescence and reflectance signals were found to be strongly influenced by shadows associated with the canopy structure. Moreover, chlorophyll fluorescence variations induced by rapid light changes (due to transient cloud shadows) were found to respond more quickly and with larger amplitude under summer conditions compared to those obtained under cold acclimation conditions. In addition, ChlF at 760 nm was observed to increase with the chlorophyll content. During this campaign, the CO₂ assimilation was measured at the forest canopy level and was found remarkably well correlated with the PRI index.     

In vitro and in vivo antiestrogenic effects of polycyclic musks in zebrafish

The polycyclic musks 6-acetyl-1,1,2,4,4,7-hexamethyltetraline (AHTN) and 1,2,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-benzopyran (HHCB) are used as fragrance ingredients in perfumes, soaps, and household cleaning products. They are known to be ubiquitously present in the aquatic environment, and because of their lipophilic nature, they tend to bioaccumulate in aquatic biota. In surface waters, concentrations between 1 ng/L and 5 microg/L have been found, depending mainly on the proportion of sewage effluents in the water. In fish, under normal environmental conditions, concentrations in the microgram per kilogram fresh weight (fw) range are found. In a previous study we showed that AHTN and HHCB exert mainly antiestrogenic effects on the human estrogen receptor alpha (ERalpha) and ERbeta in an in vitro reporter gene assay. In the current study, we assessed the in vitro antiestrogenic effects of both musks on zebrafish ERs. Antagonism was observed on zfERbeta, and more pronounced on the newly cloned zfERgamma. Using a transgenic zebrafish assay, we studied antiestrogenicity of the musks in vivo. Dose-dependent antagonistic effects were observed at concentrations of 0.1 and 1 microM AHTN and HHCB. GC-MS analysis showed that the musks bioaccumulated in the fish, with internal concentrations (15-150 mg/kg fw) which were roughly 600 times higher than the nominal test doses. To our knowledge, this is the first time that environmental contaminants are shown to be antiestrogenic in an in vivo fish assay that focuses solely on ER-mediated effects. This makes the transgenic zebrafish assay a promising tool for the rapid detection of both estrogenic and antiestrogenic effects of chemicals in fish.     

N-MOSFET oxide trap characterization induced by nitridation process using RTS noise analysis

This paper presents oxide trap characterization of nitrided and non-nitrided gate oxide N-MOSFETs using low frequency noise (LFN) measurements. The identification of defects generated by the gate oxide growth and the nitridation process is carried out using random telegraph signal noise analysis. Significant properties of traps induced by the nitridation process are pointed out. Main trap parameters, such as their nature, capture and emission times, cross-sections, energy levels, and position with respect to the Si/SiO₂ interface, are extracted. These results illustrate the potential of noise investigation for oxide characterizations.     

Risk Mitigation of Immunogenicity: A Key to Personalized Retinal Gene Therapy

Gene therapy (GT) for ocular disorders has advanced the most among adeno-associated virus (AAV)-mediated therapies, with one product already approved in the market. The bank of retinal gene mutations carefully compiled over 30 years, the small retinal surface that does not require high clinical vector stocks, and the relatively immune-privileged environment of the eye explain such success. However, adverse effects due to AAV-delivery, though rare in the retina have led to the interruption of clinical trials. Risk mitigation, as the key to safe and efficient GT, has become the focus of ‘bedside-back-to-bench’ studies. Herein, we overview the inflammatory adverse events described in retinal GT trials and analyze which components of the retinal immunological environment might be the most involved in these immune responses, with a focus on the innate immune system composed of microglial surveillance. We consider the factors that can influence inflammation in the retina after GT such as viral sensors in the retinal tissue and CpG content in promoters or transgene sequences. Finally, we consider options to reduce the immunological risk, including dose, modified capsids or exclusion criteria for clinical trials. A better understanding and mitigation of immune risk factors inducing host immunity in AAV-mediated retinal GT is the key to achieving safe and efficient GT.     

Quality of informal care is multidimensional.

Purpose: To demonstrate that assessing quality of informal care involves more than merely determining whether care recipient needs for assistance with activities of daily living (ADLs) are routinely satisfied. We investigated the extent to which potentially harmful behavior (PHB), adequate care, and exemplary care (EC) are empirically distinct dimensions of quality of care. Design: 237 care recipients completed the quality of care measures, and their caregivers completed psychosocial measures of their own depression, life events, cognitive status, and perceptions of pre-illness relationship quality. Results: Although PHB was moderately related to EC, adequate care was not associated with PHB and was only slightly related to EC. Psychosocial variables were not related to adequate care but were differentially associated with PHB and EC, providing additional evidence for the distinction between these measures of quality of care. Conclusions: ADL assistance can be adequate in the presence of PHB and/or the absence of EC. Declines in EC may signal increases in PHB, independent of adequacy of care. These findings produce a brief, portable, and more comprehensive instrument for assessing quality of informal care. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative Correlations between Radiosensitivity Biomarkers Show That the ATM Protein Kinase Is Strongly Involved in the Radiotoxicities Observed after Radiotherapy

Tissue overreactions (OR), whether called adverse effects, radiotoxicity, or radiosensitivity reactions, may occur during or after anti-cancer radiotherapy (RT). They represent a medical, economic, and societal issue and raise the question of individual response to radiation. To predict and prevent them are among the major tasks of radiobiologists. To this aim, radiobiologists have developed a number of predictive assays involving different cellular models and endpoints. To date, while no consensus has been reached to consider one assay as the best predictor of the OR occurrence and severity, radiation oncologists have proposed consensual scales to quantify OR in six different grades of severity, whatever the organ/tissue concerned and their early/late features. This is notably the case with the Common Terminology Criteria for Adverse Events (CTCAE). Few radiobiological studies have used the CTCAE scale as a clinical endpoint to evaluate the statistical robustness of the molecular and cellular predictive assays in the largest range of human radiosensitivity. Here, by using 200 untransformed skin fibroblast cell lines derived from RT-treated cancer patients eliciting OR in the six CTCAE grades range, correlations between CTCAE grades and the major molecular and cellular endpoints proposed to predict OR (namely, cell survival at 2 Gy (SF2), yields of micronuclei, recognized and unrepaired DSBs assessed by immunofluorescence with γH2AX and pATM markers) were examined. To our knowledge, this was the first time that the major radiosensitivity endpoints were compared together with the same cohort and irradiation conditions. Both SF2 and the maximal number of pATM foci reached after 2 Gy appear to be the best predictors of the OR, whatever the CTCAE grades range. All these major radiosensitivity endpoints are mathematically linked in a single mechanistic model of individual response to radiation in which the ATM kinase plays a major role.     

Chemical surface densification of hardwood through lateral monomer impregnation and in situ electron beam polymerization,Part I: density profile and surface hardness of three hardwood species

Filling wood cells with polymeric materials offers great opportunities to improve wood strength. Some applications, such as flooring, may require densification on one side of the material only. Yellow birch (Betula alleghaniensis Britt.), sugar maple (Acer saccharum Marsh.) and red oak (Quercus rubra L.) were surface densified through lateral chemical impregnation of monomers under vacuum followed by in situ electron beam polymerization. Lateral impregnation led to low mean chemical retention of 4% for sugar maple, 11% for red oak and 12% for yellow birch. X-ray densitometry and microtomography revealed an asymmetric density profile comparable to mechanically surface densified wood due to polymer-filled vessels. Scanning electron microscopy images showed presence of polymer-filled fibers beneath the surface. Brinell hardness of all species increased significantly compared to untreated wood. Low chemical retention significantly improved hardness due to localized polymer beneath the surface. Density profile characteristics were extracted from densitometry curves and correlated to hardness. Deep monomer penetration was more favorable to hardness than high surface density peak.