Mercury in Ringed Seals (Pusa hispida) from the Canadian Arctic in Relation to Time and Climate Parameters.

Mercury is found in Arctic marine mammals that are important in the diet of northern Indigenous peoples. The objectives of the present long-term study, spanning a 45-yr period, were to 1) investigate the temporal trends of total mercury (THg; muscle and liver) and selenium (Se; liver) in ringed seals (Pusa hispida) from different regions of the Canadian Arctic; and 2) examine possible relationships with age, diet, and climate parameters such as air temperature, precipitation, climatic indices, and ice-coverage. Ringed seals were collected by hunters in northern communities in the Beaufort Sea, Central Arctic, Eastern Baffin Island, Hudson Bay, and Ungava/Nunatsiavut regions (Canada) between 1972 and 2017. Mercury levels did not change through time in seal liver, but THg levels in muscle decreased in seals from Hudson Bay (-0.91%/yr) and Ungava/Nunatsiavut (-1.30%/yr). Carbon stable isotope values in seal muscle decreased significantly through time in 4 regions. Selenium-to-THg ratios were found to be >1 for all years and regions. Variation partitioning analyses across regions indicated that THg trends in seals were mostly explained by age (7.3-21.7%), climate parameters (3.5-12.5%), and diet (up to 9%); climate indices (i.e., Arctic and North Atlantic Oscillations, Pacific/North American pattern) explained the majority of the climate portion. The THg levels had a positive relationship with Arctic Oscillation for multiple regions. Associations of THg with air temperature, total precipitation, and sea-ice coverage, as well as with North Atlantic Oscillation and Pacific/North American pattern were found to vary with tissue type and geographical area. Environ Toxicol Chem 2020;39:2462-2474. © 2020 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Fisheries and Oceans Canada.

A major release of urban untreated wastewaters in the St. Lawrence River (Quebec, Canada) altered growth, reproduction, and redox status in experimentally exposed Daphnia magna.

In 2015, five billion liters of untreated urban wastewater (UWW) were released into the St. Lawrence River (Quebec, Canada) over the course of four days in order to repair the Montreal's sewer interceptor network related to the city's primary wastewater treatment plant. The UWW discharge originated mainly from household, industrial, and hospital sources. The objective of this study was to investigate the toxicological effects of this unprecedented punctual UWW release on aquatic invertebrates to gather information that could help understand the potential impacts to the receiving environment of overflow episodes occurring during heavy rain events. Water samples were collected at four impacted and non-impacted sites during and four weeks after the release. The freshwater crustacean Daphnia magna were experimentally exposed to surface water collected from UWW-impacted sites for 13 days and analyzed for life-history endpoints and suitable biomarkers related to oxidative stress (i.e., catalase, superoxide dismutase, lipid peroxidation, and glutathione-s-transferase) and reproduction (chitinase). Results indicated that D. magna growth and reproduction were significantly increased by exposure to UWWs. These effects were correlated with an increase in chitinase activity, which is primarily controlled by reproductive hormones and involved in growth, suggesting potential impacts on these processes. Results also indicated that some UWW samples might have caused oxidative stress during the release but that it was overcome by antioxidant defenses and did not lead to cellular damage. Overall, current results contribute to a better understanding of the biological impacts of UWW to aquatic invertebrates for a better stormwater management.

Trends of persistent organic pollutants in ringed seals (Phoca hispida) from the Canadian Arctic.

Ringed seals (Phoca hispida) have been used as bioindicator species of environmental contamination in Canada since the 1970s. In the present study, seals were harvested during subsistence hunts in four regions of the Canadian Arctic: Beaufort Sea, Arctic Archipelago, Hudson Bay, and coastal Labrador. An extensive suite of persistent organic pollutants (POPs) was determined in seal blubber collected for multiple years between 1972 and 2016. Results from this long-term study indicate geographical differences in the contaminant concentrations in seals and the significant general decrease of most POPs, including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and related compounds, chlordanes (CHL), and hexachlorocyclohexanes (HCH) over time in ringed seals. The highest decrease rates (up to -9.1%/year for α-HCH) were found in seals from the Hudson Bay region where all chemicals investigated have significantly decreased since 1986. Significant increases in concentrations of hexachlorobenzene (HCB) in seals from Labrador and ß-HCH in Sachs Harbour, NT and Arctic Archipelago were observed. Site-specific and contaminant-specific associations between climate pattern (i.e., Arctic Oscillation, North Atlantic Oscillation, and Pacific/North American pattern) and mean ice-coverage (total, first-year ice, and old-ice) were found at sites with the longest time trend data (i.e., Arviat, Sachs Harbour/Ulukhaktok and Resolute Bay). Overall, results suggest that North American and international regulations have led to the long-term reduction of most POPs in Canadian Arctic ringed seals by reducing emissions from primary sources. However, other sources of legacy compounds (e.g., environmental reservoirs) as well changes in food web composition and structure in relation to climate changes could also be influencing the very slow rates of decline, or stable levels, of contaminants found in seals at some sites. Further work is warranted to discern between co-variation of climate changes and contaminant concentrations and cause-and-effect relationships.

Spatial and temporal trends of alternative flame retardants and polybrominated diphenyl ethers in ringed seals (Phoca hispida) across the Canadian Arctic.

Concentrations of alternative flame retardants and polybrominated diphenyl ethers (PBDEs) were analyzed in ringed seal (Phoca hispida) blubber collected across the Canadian Arctic during subsistence hunts between 1998 and 2013. More than 80% of sampled animals were females and juvenile males. The highest mean ΣPBDE concentrations (sum of 13 congeners) were found in seals from Nain (Nunatsiavut) as well as Inukjuaq and Arviat (Hudson Bay) and the lowest mean levels were found in seals from Lancaster Sound. BDE-47 and -99 were the predominant PBDE congeners quantified in ringed seals. The most frequently detected non-PBDE flame retardants were polybrominated biphenyl 101 (BB-101, 57% of samples analyzed for this chemical), hexabromocyclododecane (HBCDD; 38%), hexabromobenzene (HBB, 30%), and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTeBB, 23%). The relative trophic position of seals, estimated using stable isotopes, did not vary over time and did not influence flame retardant blubber concentrations. The relative carbon source increased over time at Arviat and Resolute Bay and weak relationships were observed with ΣPBDEs in blubber of seals. ΣPBDEs increased significantly from 1998 to 2008 in ringed seals from East Baffin and subsequently decreased in recent years. PBDE levels at other sites fluctuated slightly over time. HBCDD concentrations increased at several sites over the past decade. The presence of flame retardants in ringed seals suggests their persistence and their continuous inputs in the Canadian Arctic environment. Monitoring and research on the effects of these contaminants in seals are warranted given the importance of this species in Arctic marine food webs and for local communities.

Spatial and temporal variations of a saxitoxin analogue (LWTX-1) in Lyngbya wollei (Cyanobacteria) mats in the St. Lawrence River (Québec, Canada).

The concentration of the saxitoxin analogue LWTX-1 was quantified in samples of the benthic filamentous cyanobacterium Lyngbya wollei (Farlow ex Gomont) Speziale and Dyck collected in two fluvial lakes of the St. Lawrence River (Canada) over the 2006-2013 period. The study was aimed at documenting the spatial (between fluvial lakes, between sites within each lake) and temporal (inter-annual, monthly) variations of toxin concentration in relation with hydrological (water level), physical (water temperature, conductivity, transparency), chemical (nutrients in overlying water) and biological (L. wollei biomass and mat condition) characteristics. Toxin concentration was hypothesized to vary seasonally with biomass accumulation and environmental conditions. Toxin concentrations measured in Lake Saint-Louis (51±40µg LWTX-1g-1 DM, N=29 days in 2007, 2009-2011) were double those in Lake Saint-Pierre (25±31µg LWTX-1g-1 DM, N=26 days in 2006-2008, 2012-2013); however, August 2007 measurements taken from both lakes did not differ significantly. Ten of the twelve highest values (>100µg LWTX-1g-1 DM) were obtained from Lake Saint-Louis, between April and October in 2007, 2010 or 2011. Under ice samples showed intermediate concentrations of LWTX-1 (42±9µg LWTX-1g-1 DM, N=2). Concentrations of LWTX-1 were positively correlated with Secchi depth (r=0.59, p<0.001), L. wollei biomass (Spearman r=0.31, p<0.01) and %N in filaments (r=0.48, p<0.001), suggesting toxin production was linked to mat growth and metabolism rather than water quality. Although LWTX-1 has been reported to have a low toxicity, monitoring of L. wollei abundance is required to assess the environmental and human health risks posed by this taxon in the St. Lawrence - Great Lakes system.

Pulmonary rehabilitation in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and an important worldwide cause of disability and handicap. Centered around exercise training, pulmonary rehabilitation is a global, multidisciplinary, individualized and comprehensive approach acting on the patient as a whole and not only on the pulmonary component of the disease. Pulmonary rehabilitation is now well recognized as an effective and key intervention in the management of several respiratory diseases particularly in COPD. Modern and effective pulmonary rehabilitation programs are global, multidisciplinary, individualized and use comprehensive approach acting on the patient as a whole and not only on the pulmonary component of the disease. In the last two decades interest for pulmonary rehabilitation is on the rise and a growing literature including several guidelines is now available. This review addresses the recent developments in the broad area of pulmonary rehabilitation as well as new methods to consider in the development of future and better programs. Modern literature for rationale, physiopathological basis, structure, exercise training as well challenges for pulmonary rehabilitation programs are addressed. Among the main challenges of pulmonary rehabilitation, efforts have to be devoted to improve accessibility to early rehabilitation strategies, not only to patients with COPD but to those with other chronic respiratory diseases.

A unique case of Hajdu-Cheney syndrome and squamous cell carcinoma of the anus.

OBJECTIVE: Hajdu-Cheney syndrome (HCS), first described in 1948 by Hajdu and independently in 1965 by Cheney, is an extremely rare disorder characterized by severe and excessive bone resorption leading to osteoporosis, with a wide range of other systemic complications from connective tissue and bone dysplasia. Currently there are approximately 50 distinct cases reported in the literature. There have been several reports associating polycystic kidneys with HCS and several other connective tissue disorders, suggesting a possibility of a hyperproliferative component to the syndrome. No articles exist in the current literature describing a case of HCS with concurrent carcinoma. Here, we present a case of a 54-year-old nonimmune compromised woman with multiple stigmata of HCS and recently diagnosed anal squamous cell carcinoma. METHOD: This is a case report of HCS and stage T3N0 squamous cell carcinoma of the anus. RESULTS: This is the first report of a patient with HCS with malignancy. CONCLUSIONS: We present a patient with HCS who developed anal squamous cell carcinoma. The mechanism of HCS, which is still unknown, may either make patients more susceptible to carcinoma or may just be a reflection of the normal incidence of anal squamous cell carcinoma given attributable risk factors.

Dalitz plot analysis of the decay D(+)-->K(-)pi(+)pi(+) and indication of a low-mass scalar Kpi resonance.

We study the Dalitz plot of the decay D(+)-->K(-)pi(+)pi(+) with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known Kpi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K(*)(0)(1430) to float, we obtain values consistent with those from PDG but the chi(2) per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797+/-19+/-43 MeV/c(2) and width 410+/-43+/-87 MeV/c(2). The mass and width of the K(*)(0)(1430) become 1459+/-7+/-5 MeV/c(2) and 175+/-12+/-12 MeV/c(2), respectively. Our results provide new information on the scalar sector in hadron spectroscopy.

Overview of results from the WaterTox intercalibration and environmental testing phase II program: Part 1, statistical analysis of blind sample testing.

There is an urgent need to evaluate the presence of toxicants in waters used for human consumption and to develop strategies to reduce and prevent their contamination. The International Development Research Centre undertook an intercalibration project to develop and validate a battery of bioassays for toxicity testing of water samples. The project was carried out in two phases by research institutions from eight countries that formed the WaterTox network. Results for the first phase were reported in the special September 2000 issue of Environmental Toxicology. Phase II involved toxicity screening tests of environmental and blind samples (chemical solutions of unknown composition to participating laboratories) using the following battery: Daphnia magna, Hydra attenuata, seed root inhibition with Lactuca sativa, and Selenastrum capricornutum. This battery was also used to assess potential toxicity in concentrated (10x) water samples. Results are presented for a set of six blind samples sent to the participating laboratories over a 1-year period. Analyses were performed for each bioassay to evaluate variations among laboratories of responses to negative controls, violations of test quality control criteria, false positive responses induced by sample concentration, and variability within and between labs of responses to toxic samples. Analyses of the data from all bioassays and labs provided comparisons of false positive rates (based on blind negative samples), test sensitivities to a metal or organic toxicant, and interlaboratory test variability. Results indicate that the battery was reliable in detecting toxicity when present. However, some false positives were identified with a concentrated soft-water sample and with the Lactuca and Hydra (sublethal end-point) tests. Probabilities of detecting false positives for individual and combined toxic responses of the four bioassays are presented. Overall, interlaboratory comparisons indicate a good reliability of the battery.

Synthesis and evaluation of novel dipeptide-bound 1,2,4-thiadiazoles as irreversible inhibitors of guinea pig liver transglutaminase.

Herein we report the synthesis and evaluation of 14 novel peptides as potential irreversible inactivators of guinea pig liver transglutaminase (TGase). These peptides were designed to resemble Cbz-L-Gln-Gly, known to be a good TGase substrate, and to include a 1,2,4-thiadiazole group. The side chain length of the amino acid residue bearing the inhibitor group was also varied in order to permit investigation of this effect. Their inactivation rate constants were measured using a direct continuous spectrophotometric method and were found to vary between 0.330 to 0.89 microM(-1) min(-1).

Direct measurement of the pion valence-quark momentum distribution, the pion light-cone wave function squared.

We present the first direct measurements of the pion valence-quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c pi(-) into dijets from a platinum target at Fermilab experiment E791. The results show that the /q&q> light-cone asymptotic wave function describes the data well for Q2 approximately 10 (GeV/c)(2) or more. We also measured the transverse momentum distribution of the diffractive dijets.

Observation of color-transparency in diffractive dissociation of pions.

We have studied the diffractive dissociation into dijets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t(min)-->0), we find that when the per-nucleus cross section for this process is parametrized as sigma = sigma0Aalpha, alpha has values near 1.6, the exact result depending on jet transverse momentum. These values are in agreement with those predicted by theoretical calculations of color-transparency.

Search for rare and forbidden Charm Meson decays D0 --> Vl+l- and hhll.

We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the D0 (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a rho(0), K( *0), or straight phi vector meson or a nonresonant pi(pi), Kpi, or KK pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).

Study of the D(+)(s)-->pi(-)pi(+)pi(+) decay and measurement of f(0) masses and widths.

From a sample of 848+/-44 D(+)(s)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)(s)-->pi(-)pi(+)pi(+))/gamma(D(+)(s)-->straight phipi(+)) = 0.245+/-0.028(+0.019)(-0.012). Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels rho(0)(770)pi(+), rho(0)(1450)pi(+), f(0)(980)pi(+), f(2)(1270)pi(+), and f(0)(1370)pi(+). We also present the values obtained for masses and widths of the resonances f(0)(980) and f(0)(1370).

Experimental evidence for a light and broad scalar resonance in D(+) --> pi(-)pi(+)pi(+) decay.

From a sample of 1172 +/- 61 D(+)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)-->pi(-)pi(+)pi(+))/gamma(D(+)-->K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.

Biomarkers in zebra mussels (Dreissena polymorpha) for the assessment and monitoring of water quality of the St Lawrence River (Canada).

Five biomarkers (MT: metallothionein-like proteins, EROD: ethoxyresorufin ortho-dééthylase, DNA strand breaks, LPO: peroxidation of lipids, VG: vitellogenin-like protiens) were measured in the soft tissues of zebra mussels (Dreissena polymorpha) in order to assess the spatial variation of exposure to contaminants along the St Lawrence River (Canada). Fifteen mussels >25 mm shell length were analyzed from each of the 13 sampling sites. Significant differences between sites were noted for all biomarkers, but the general level of variability was low. Three biomarkers (DNA, LPO and VG) exhibited a similar pattern of spatial variation while MT and EROD had distinct and specific patterns. MT had the strongest discriminating power and EROD showed the largest range of variation among sites. Highest biomarker responses were measured in specimens from local contaminated sites such as harbors and industrial sectors. A positive relationship was found between MT and copper (Cu), but no significant correlation was observed between other biomarker responses and the levels of ten trace metals bioaccumulating in the zebra mussels tissues. Results indicate that the measurement of biomarker responses is technically feasible. The performance of each biomarker is assessed in the context of the role and advantages of selecting a battery of biomarkers for detecting contamination problems. The use of zebra mussels as a sentinel species for biomonitoring potential toxic effects in situ is discussed.

Dental caries in Quebec adults aged 35 to 44 years.

BACKGROUND: The purpose of this study was to assess the prevalence of dental caries in Quebec adults aged 35 to 44. METHODS: A stratified sample was used. The participation rate was 77% for the questionnaire and 44.5% for the oral examination. A total of 2,110 people were examined. The World Health Organization's caries criteria were used. Examiner agreement with gold standard dentist was excellent at the end of the nine-day training session (Kappa index > 0.8). RESULTS: The level of caries experience is very high in Quebec adults aged 35 to 44. Almost half of dental surfaces (65 of 148) have been affected. These surfaces are mostly missing (39.3) or filled (23.9). However, there were 1.8 decayed surfaces in need of treatment per adult, and more than half the people (55.5%) had no untreated decayed surfaces. Almost three-quarters of decayed surfaces were present in only 14% of the people; lower family income and lower education are risk factors. CONCLUSION: Comparison between Quebec and industrialized countries (United States, England and the Netherlands) shows that in adults 35 to 44, the mean number of decayed teeth is low (between 1.0 and 2.2) and the mean number of filled teeth is relatively similar (between 9.6 and 11.1); however, Quebec has a higher percentage than the United States of edentulous people. As well, in dentate adults, there are 1.6 times more missing teeth among Quebecers than among Americans.

Delirium in terminal cancer: a prospective study using daily screening, early diagnosis, and continuous monitoring.

A pilot prospective cohort study was conducted to determine delirium frequency and outcome in cancer patients consecutively hospitalized for terminal care (median stay: 12 days). Screening for delirium symptoms was performed daily, using the Confusion Rating Scale. Patients positive on screening had a diagnostic assessment within 24 hours using the Confusion Assessment Method. Monitoring of symptoms was continued until death. Eighteen (20%) of the 89 study patients were positive on screening at admission. Among the 71 patients free of delirium at admission, the incidence of confirmed delirium was 32. 8% (95% CI, 21.3-44.3%). Patients positive on screening received a higher mean equivalent parenteral daily dose of morphine than other patients (72 mg vs. 41 mg, p = 0.08). Significant symptom improvement occurred in 16 (50%) of the 32 delirious cases. Delirium is a serious and frequent complication in terminal cancer whose outcome may not be as poor as previously considered.

Removal of a PCR inhibitor and resolution of DNA STR types in mixed human-canine stains from a five year old case.

The analysis of biological trace evidence from a reopened investigation into a 1991 murder from Vernon, B.C. revealed mixed human and dog bloodstains on blue jean pants that contained a PCR inhibitory substance. The presence of the inhibitory substance was detected by the inhibition caused from adding a small aliquot of the test DNA extract into a PCR reaction designed to produce a known standard product. The removal of the PCR inhibitory substance was accomplished by treating the extracted DNA with Thiopropyl Sepharose 6B beads. DNA profiles from two human contributors and a canine were obtained using species specific polymorphic STR markers. The two human DNA profiles obtained from blue jean pants were resolved, one matched the suspect and the other matched the victim. The DNA profile from the canine component matched that obtained from the known sample of the victim's dog who was also slain during the assault. This evidence along with other DNA typing evidence was critical in obtaining a resolution of the case.

French adaptation of the shortened version of the Profile of Mood States.

The French adaptation and validation of the short version of the Profile of Mood States is examined. A sample of 110 women diagnosed with breast cancer and 50 men with prostate cancer were administered the French Canadian adaptation of the shortened version of the profile (37 items). Means, test-retest correlations, and internal consistency coefficients (alpha) replicated the English initial validation. These results support the reliability of the French Canadian version. In addition, significant decrease from initial to retest testing for Anxiety, Depression, and Confusion subscales also supported construct validity.