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Thyroid hormones (TH) are critical for brain development and insufficiencies can lead to structural abnormalities in specific brain regions. Administration of the goitrogen propylthiouracil (PTU) reduces TH production by inhibiting thyroperoxidase (TPO), an enzyme that oxidizes iodide for the synthesis of TH. TPO activity is iron (Fe)-dependent and dietary iron deficiency (FeD) also reduces circulating levels of TH. We have previously shown that modest degrees of TH insufficiency induced in pregnant rat dams alters the expression of TH-responsive genes in the cortex and hippocampus of the neonate, and results in the formation of a subcortical band heterotopia (SBH) in the corpus callosum (Royland et al., 2008, Bastian et al., 2014, Gilbert et al., 2014). The present experiment investigated if FeD alone was sufficient to induce a SBH or if FeD would augment SBH formation at lower doses of PTU. One set of pregnant rats was administered 0, 1, 3, or 10ppm of PTU via drinking water starting on gestational day (GD) 6. FeD was induced in a 2nd set of dams beginning on GD2. A third set of dams received the FeD diet from GD2 paired with either 1ppm or 3ppm PTU beginning on GD6. All treatments continued until the time of sacrifice. On PN18, one female pup from each litter was sacrificed and the brain examined for SBH. We observed lower maternal, PN2 and PN18 pup serum T4 in response to PTU. FeD reduced serum T4 in pups on PN16, but did not affect serum T4 in dams or PN2 pups. Neither did FeD in combination with PTU alter T4 levels in dams on PN18 or pups on PN2 compared to PTU treatment alone. By PN16, however more severe T4 reductions were observed in pups when FeD was combined with PTU. SBH increased with increasing dosage of PTU, but counter to our hypothesis, no SBH was detected in the offspring of FeD dams. As such, T4 levels in dams and newborn pups rather than older neonates appear to be a better predictor SBH associated with TH insufficiency. These data indirectly support previous work indicating prenatal TH insufficiency but not postnatal TH insufficiency in offspring is required for SBH formation.

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BACKGROUND: To evaluate surgical outcome and survival benefit after quaternary cytoreduction (QC) in epithelial ovarian cancer (EOC) relapse. METHODS: We systematically evaluated all consecutive patients undergoing QC in our institution over a 12-year period (October 2000-January 2012). All relevant surgical and clinical outcome parameters were systematically assessed. RESULTS: Forty-nine EOC patients (median age: 57; range: 28-76) underwent QC; in a median of 16 months (range:2-142) after previous chemotherapy. The majority of the patients had an initial FIGO stage III (67.3%), peritoneal carcinomatosis (77.6%) and no ascites (67.3%). At QC, patients presented following tumour pattern: lower abdomen 85.7%; middle abdomen 79.6% and upper abdomen 42.9%. Median duration of surgery was 292 min (range: a total macroscopic tumour clearance could be achieved. Rates of major operative morbidity and 30-day mortality were 28.6% and 2%, respectively.Mean follow-up from QC was 18.41 months (95% confidence interval (CI):12.64-24.18) and mean overall survival (OS) 23.05 months (95% CI: 15.5-30.6). Mean OS for patients without vs any tumour residuals was 43 months (95% CI: 26.4-59.5) vs 13.4 months (95% CI: 7.42-19.4); P=0.001. Mean OS for patients who received postoperative chemotherapy (n=18; 36.7%) vs those who did not was 40.5 months (95% CI: 27.4-53.6) vs 12.03 months (95% CI: 5.9-18.18); P<0.001.Multivariate analysis indentified multifocal tumour dissemination to be of predictive significance for incomplete tumour resection, higher operative morbidity and lower survival, while systemic chemotherapy subsequent to QC had a protective significant impact on OS. No prognostic impact had ascites, platinum resistance, high grading and advanced age. CONCLUSION: Even in this highly advanced setting of the third EOC relapse, maximal therapeutic effort combining optimal surgery and chemotherapy appear to significantly prolong survival in a selected patients 'group'.

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We evaluated the effectiveness of Ambersorb, a carbonaceous resin, in reducing bioavailability of polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments collected from the field. In laboratory studies, sediment pore-water concentrations of eight unsubstituted PAHs were significantly decreased after resin addition. Reduced PAH concentrations in oligochaete tissues from a laboratory bioaccumulation test, along with increased survival/reproduction and reduced photo-enhanced toxicity and sediment avoidance, also resulted from sediment treatment with Ambersorb. Resin amendment also decreased pore-water PAH concentrations in field deployed sediments but did not improve benthic invertebrate colonization. Prediction of partitioning of PAHs between solid and aqueous phases in the test sediments was complicated by the presence of coal and soot. However, accurate predictions of bioavailability were achieved based on pore-water chemistry. Overall, these studies show that the addition of high affinity sorbents effectively reduces pore-water PAH concentrations and bioavailability and suggests that sorbent addition may serve as an option for in situ remediation of some contaminated sediments.

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Within the last decade, there have been increasing reports of malformed amphibians across North America. Recently, it has been suggested that hind-limb malformations are a consequence of xenobiotic disruption of developmental pathways regulated by retinoids. To assess the validity of this hypothesis, the developmental toxicity of all-trans retinoic acid (RA) was examined in Xenopus laevis and four North American anurans, at several life stages. To determine the effects of RA on embryogenesis, mid-blastula stage embryos were exposed to 0, 6.25, 12.5, 25, or 50 ng RA/ml for 24 h. To evaluate the effects of RA on hind-limb development, early- and mid-limb bud stage tadpoles were exposed to RA concentrations of 0, 250, 500, 750, 1000, or 1250 ng RA/ml for 24 h. Mid-blastula RA exposure resulted in a concentration-dependent increase in dysmorphogenesis and mortality in the three species examined (R. clamitans, R. septentrionalis and X. laevis). RA exposure at stage 51 in X. laevis and stage 28 in R. sylvatica resulted in concentration-dependent increases in reductions and deletions of the hind limb. However, RA was ineffective at inducing hind-limb abnormalities in stages 26 and 28 of R. pipiens, stage 28 in R. clamitans, or stage 48 in X. laevis tadpoles. These results indicate that mid-blastula stage embryos are more sensitive to RA-induced dysmorphogenesis and mortality than limb-bud stage tadpoles. The significance of these findings is discussed in the context of the possible occurrence of retinoid mimics in the environment.

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Toxicity of some polycyclic aromatic hydrocarbons (PAHs) can increase by an order of magnitude, or more, in the presence of solar ultraviolet (UV) radiation. In the environment, PAHs exist as complex mixtures, which generally would include multiple PAHs that could cause photoinduced toxicity. Hence, to accurately predict the potential ecological risk of phototoxic PAHs, it is critical to understand their joint toxicity. In this study, we exposed the oligochaete Lumbriculus variegatus to the phototoxic PAHs anthracene, fluoranthene, and pyrene, both singly and as binary mixtures for 96 h. Following this, the animals were exposed to UV light for an additional 96 h, during which periodic observations of mortality were made. Time-dependent phototoxicity of the binary PAH mixtures, expressed as a function of the product of UV light intensity and PAH dose (in the tissue of the animals), was adequately described using a concentration addition model. Given the probability that the PAHs examined acted via a common mechanism of action, this result was consistent with expectations. These data highlight the need to consider the combined photoactivation potential of PAH mixtures and provide the technical basis for a modeling approach to predict their ecological risk.

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A life-cycle test with the macroinvertebrate Chironomus tentans was conducted with 4-nonylphenol. The chironomids were exposed to a series of concentrations of 4-nonylphenol via the water, in an intermittent (2 times/day) water renewal system. The test included evaluation of a number of developmental (e.g., growth) and reproductive (e.g., emergence, fecundity, viability) endpoints through parental and into F1 generations. Reductions in survival were observed in 20-day-old larvae at the highest test concentration, which corresponded to no-observable- and lowest-observable-effect concentrations of 42 and 91 microg/liter, respectively. No significant effects on larval growth (20 days), organism survival past 20 days, emergence success or pattern, sex ratio, fecundity, or egg viability were observed at any treatment level. Qualitative observations indicated an increase in deformed egg masses at the highest test concentrations; however, the biological significance of this is uncertain.

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Four sites from a stream system near Huntsville, Alabama, contaminated with DDT and its metabolites, were sampled using a coring device. Grab samples were also collected at these and five other sites. Analytical and toxicological evaluations were made on both sets of samples. Core samples provided vertical delineation of toxicity and contamination in sediments, and documented periods of sedimentation with clean material, which appears to be isolating the contaminated sediments from benthic communities. Grab samples yielded less information about the sites. Relationships between DDT concentration and sediment toxicity to Chironomus tentans were similar regardless of the sampling method. Substantial increases in toxicity occurred in most samples when concentrations exceeded 3000 micrograms of DDT residue/g organic carbon.

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