A multiple lines of evidence approach for the ecological risk assessment of an accidental bitumen release from a steam assisted gravity drainage (SAGD) well in the Athabasca oil sands region.

To assess the ecological impacts of two independent accidental bitumen releases from two steam assisted gravity drainage (SAGD) wells in the Athabasca oil sands region, a multiple lines of evidence (LOE) approach was developed. Following the release in 2010, action was taken to minimize environmental impact, including the selective removal of the most highly impacted vegetation and the use of oil socks to minimize possible runoff. An ecological risk assessment (ERA) was then conducted based on reported concentrations of bitumen related contaminants in soil, vegetation, and water. Results of biological assessments conducted at the site were also included in the risk characterization. Overall, the conclusion of the ERA was that the likelihood of long-term adverse health effects to ecological receptors in the area was negligible. To provide evidence for this conclusion, a small mammal sampling plan targeting Southern red-back voles (Myodes gapperi) was carried out at two sites and two relevant reference areas. Voles were readily collected at all locations and no statistically significant differences in morphometric measurements (i.e., body mass, length, foot length, and adjusted liver weight) were found between animals collected from impact zones of varying levels of coverage. Additionally, no trends corresponding with bitumen coverage were observed with respect to metal body burden in voles for metals that were previously identified in the source bitumen. Hepatic ethoxyresorufin-O-deethylase (EROD) activity was statistically significantly elevated in voles collected from the high impact zones of sites compared to those collected from the reference areas, a finding that is indicative of continued exposure to contaminants. However, this increase in EROD was not correlated with any observable adverse population-wide biological outcomes. Therefore the biological sampling program supported the conclusion of the initial ERA and supported the hypothesis of no significant long-term population-wide ecological impact of the accidental bitumen releases.

Progesterone and HMOX-1 promote fetal growth by CD8+ T cell modulation.

Intrauterine growth restriction (IUGR) affects up to 10% of pregnancies in Western societies. IUGR is a strong predictor of reduced short-term neonatal survival and impairs long-term health in children. Placental insufficiency is often associated with IUGR; however, the molecular mechanisms involved in the pathogenesis of placental insufficiency and IUGR are largely unknown. Here, we developed a mouse model of fetal-growth restriction and placental insufficiency that is induced by a midgestational stress challenge. Compared with control animals, pregnant dams subjected to gestational stress exhibited reduced progesterone levels and placental heme oxygenase 1 (Hmox1) expression and increased methylation at distinct regions of the placental Hmox1 promoter. These stress-triggered changes were accompanied by an altered CD8+ T cell response, as evidenced by a reduction of tolerogenic CD8+CD122+ T cells and an increase of cytotoxic CD8+ T cells. Using progesterone receptor- or Hmox1-deficient mice, we identified progesterone as an upstream modulator of placental Hmox1 expression. Supplementation of progesterone or depletion of CD8+ T cells revealed that progesterone suppresses CD8+ T cell cytotoxicity, whereas the generation of CD8+CD122+ T cells is supported by Hmox1 and ameliorates fetal-growth restriction in Hmox1 deficiency. These observations in mice could promote the identification of pregnancies at risk for IUGR and the generation of clinical interventional strategies.

A case of progressive multifocal leukoencephalopathy in a patient treated with infliximab.

We describe a 72-year-old white man with erosive rheumatoid arthritis in whom subacute neurologic and psychiatric symptoms developed after 3 years of treatment with infliximab, prednisone, and methotrexate. White matter demyelination was seen on magnetic resonance imaging of the brain, and progressive multifocal leukoencephalopathy (PML) was ultimately confirmed by brain biopsy. The patient was treated with supportive therapy and discontinuation of disease-modifying antirheumatic drugs, resulting in stabilization of the disease process. The patient survived, but neurologic and cognitive deficits persisted. The distribution and pathology of this patient's disease are unique from almost all reported incidents of oral methotrexate-associated leukoencephalopathy. The pathogenesis of disease may be linked to a T cell-mediated process that is potentially impacted by infliximab. This case provides the first reported evidence that PML can be seen in association with infliximab therapy.

Bisphenol-A exposure during the period of blastocyst implantation alters uterine morphology and perturbs measures of estrogen and progesterone receptor expression in mice.

Bisphenol-A (BPA) has estrogenic properties both in vitro and in vivo. We investigated its impacts upon uterine morphology and estrogen and progesterone receptors after injection on gestational days 1-4 in doses known to disrupt pregnancy. Blastocyst implantation was significantly reduced by doses of 6.75 and 10.125 mg/animal. Uterine luminal area expanded substantially in response to increasing doses of BPA. Luminal epithelial cell height increased following exposure to 10.125 mg/animal, whereas there were no differences in the number of corpora lutea among conditions. The proportion of cells staining positively for estrogen receptors was affected non-monotonically, showing highest levels at 3.375 mg/animal and lowest levels at 10.125 mg/animal. Similarly progesterone receptor expression measured through western blots related non-monotonically to dose, being highest at 3.375 mg/animal and diminishing with increasing dose. These results suggest that BPA exposure during early gestation acts at the uterus to disrupt intrauterine implantation, consistent with an estrogenic effect.

Excretion and binding of tritium-labelled oestradiol in mice (Mus musculus): implications for the Bruce effect.

Male mouse urine contains 17beta-oestradiol (E(2)) and other steroids. Given that males actively direct urine at proximate females and intrauterine implantation of blastocysts is vulnerable to minute amounts of exogenous oestrogens, males' capacity to disrupt early pregnancy could be mediated by steroids in their urine. When male mice were implanted with osmotic pumps containing tritium-labelled E(2) ((3)H-E(2)) or injected i.p. with (3)H-E(2), radioactivity was reliably detected in their urine. Following intranasal administration of (3)H-E(2) to inseminated females, radioactivity was detected in diverse tissue samples, with there being significantly more in reproductive tissues than in brain tissues. When urine was taken from males injected with (3)H-E(2), and then intranasally administered to inseminated females, radioactivity was detected in the uterus, olfactory bulbs, and mesencephalon and diencephalon (MC+DC). When inseminated and ovariectomised females were perfused at the point of killing to remove blood from tissues, more radioactivity was detected in the uterus than in muscle, olfactory bulbs, MC+DC and cerebral cortex. Pre-treatment with unlabelled E(2) significantly reduced the uptake of (3)H-E(2) in the uterus. Taken with evidence that males deliver their urine to the nasal area of females, these results indicate that male urinary E(2) arrives in tissues, including the uterus, where it could lead to the disruption of blastocyst implantation.

Preputialectomised and intact adult male mice exhibit an elevated urinary ratio of oestradiol to creatinine in the presence of developing females, whilst promoting uterine and ovarian growth of these females.

Exposure to novel adult males and their urine can hasten the onset of sexual maturity in female mice. Some evidence implicates chemosignals from males' preputial glands, while other evidence suggests that male urinary steroids, especially 17beta-oestradiol, contribute to this effect. The present experiment was designed to determine whether preputial gland removal would influence the capacity of males to accelerate female sexual development, and to measure male urinary oestradiol and testosterone in the presence or absence of these glands. Juvenile females aged 28 days were housed for two weeks in isolation or underneath two outbred males that had undergone preputialectomy or sham surgery. Urine samples were collected non-invasively from males that were isolated or exposed to females, then assayed for oestradiol, testosterone and creatinine. Combined uterine and ovarian mass from females sacrificed at 43 days of age was increased by exposure to males, regardless of whether or not these males had been preputialectomised. Male urinary creatinine was reduced by exposure to developing females. Creatinine-adjusted oestradiol and testosterone were significantly greater in female-exposed than in isolated males, in both preputialectomised and intact males. These data suggest that the preputials are not necessary for the capacity of males to hasten female uterine and ovarian growth. As exogenous oestrogens can promote uterine growth and other parameters of female reproductive maturation, oestradiol in males' urine may contribute to earlier sexual maturity in male-exposed females.

Exposure to developing females induces polyuria, polydipsia, and altered urinary levels of creatinine, 17beta-estradiol, and testosterone in adult male mice (Mus musculus).

Novel male mice can accelerate reproductive maturation in proximal developing females, an effect mediated by the chemistry of the males' urine. Exogenous estrogens can similarly accelerate female sexual development. In Experiment 1, adult male mice were housed across wire grid from either empty compartments or those containing post-weanling females. Proximity of females caused males to urinate more, progressively over days of exposure, with most urination directed towards females' compartments. Male urine collected after 5 days in these conditions was analyzed by enzyme immunoassay for 17beta-estradiol, testosterone, and creatinine. Urinary creatinine of isolated males significantly exceeded that of female-exposed males. Unadjusted urinary steroids also trended toward higher levels in isolates, but creatinine-adjusted estradiol and testosterone of female-exposed males significantly exceeded that of isolated males. In Experiment 2, measurement of water consumption indicated significantly greater drinking by female-exposed as opposed to isolated males. In Experiment 3, males were housed in isolation or beside post-weanling intact (sham-operated) females, ovariectomized females, or intact (sham-operated) males. Male water consumption was elevated in all conditions involving social contact. Urinary creatinine was significantly lower in female-exposed males compared to isolated controls, while unadjusted testosterone was significantly lower in males in all social conditions. Again, creatinine-adjusted estradiol in female-exposed males significantly exceeded that of isolates. These data indicate that adult males drink and urinate more, have more dilute urine, and have a higher ratio of estradiol to creatinine when they are near developing females. These dynamics increase females' exposure to urinary steroids and other urinary constituents that can hasten sexual maturity.

Impact of acute bisphenol-A exposure upon intrauterine implantation of fertilized ova and urinary levels of progesterone and 17beta-estradiol.

Bisphenol-A (BPA), a monomer used in production of polycarbonate plastics and epoxy resins, has established estrogenic properties. We assessed the impact of acute and repeated subcutaneous BPA administration upon intrauterine implantation of fertilized ova and urinary levels of 17beta-estradiol and progesterone in inseminated female mice. In Experiment 1, females received varied doses of BPA on days 1-4 of gestation. Daily doses of 6.75 and 10.125mg/animal significantly reduced the number of implantation sites. Urinary progesterone was significantly reduced by the higher dose, but no other dose had an effect on progesterone levels and no dose altered estradiol levels. In Experiment 2, inseminated females received a single dose of BPA on days 0, 1, or 2 of gestation. A single dose of 10.125mg reduced the number of implantation sites when given on day 0 or day 1, and 6.75mg on day 1 also produced fewer implantation sites, but there was no such effect of any dose when administered on day 2. These data show a lower threshold for BPA-induced pregnancy disruption than previously reported, also indicating effects of just one exposure. They confirm that this disruption is due to the actions of BPA upon implantation sites, and show that higher doses can influence systemic progesterone levels.

The onset of puberty in female mice as reflected in urinary steroids and uterine/ovarian mass: interactions of exposure to males, phyto-oestrogen content of diet, and ano-genital distance.

Development of puberty in female mice was examined in relationship with the ano-genital distance index (AGDI), phyto-oestrogen content of diet and exposure to males post weaning. Throughout gestation and post-natal development, females were exposed to a regular diet or a nutritionally similar diet deficient in phyto-oestrogens. After segregation at weaning on the basis of short or long AGDI, an indirect measure of in utero androgen exposure, females were housed alone or underneath two outbred adult males for 2 weeks. Female urinary samples were collected non-invasively throughout this exposure, then assayed for oestradiol, progesterone and creatinine. Females were then killed and uterine and ovarian mass was determined. Urinary oestradiol was substantially reduced in females raised on the phyto-oestrogen-free diet. Oestradiol levels were more dynamic over days in urine of male-exposed females, especially among those on the regular diet. Urinary progesterone was not strongly influenced by diet. Progesterone was more dynamic in urine of male-exposed females, and was generally elevated compared with levels in isolated females, the size of this effect dependent on AGDI, diet and whether the measure was adjusted for creatinine. Urinary creatinine was elevated by the phyto-oestrogen-free diet and reduced by male exposure, tending to decline over days in females exposed to males. Male exposure increased uterine and ovarian mass and was influenced by AGDI in interaction with diet and male exposure.