Field transplantation of a freshwater bivalve, Pyganodon grandis, across a metal contamination gradient. I. Temporal changes in metallothionein and metal (Cd, Cu, and Zn) concentrations in soft tissues

1995 ◽  
Vol 52 (4) ◽  
pp. 690-702 ◽  
Author(s):  
Y. Couillard ◽  
P. G. C. Campbell ◽  
A. Tessier ◽  
J. C. Auclair ◽  
J. Pellerin-Massicotte
Keyword(s):  
Soft Tissues ◽  
Shell Growth ◽  
Mining Area ◽  
Metal Exposure ◽  
Steady Increase ◽  
Freshwater Bivalve ◽  
Slow Increase ◽  
Metal Levels ◽  
Pyganodon Grandis ◽  
Over Time

To test the response of the freshwater bivalve Pyganodon grandis (formerly Anodonta grandis) to increased metal exposure in the field, we transferred specimens (8 cm length; 4–6 years old) from a less to a more contaminated lake in the mining area of Rouyn-Noranda, in northwestern Québec. The transplanted bivalves were maintained in open enclosures placed in the bottom sediments of the contaminated lake. Up to 16 individuals were removed from pairs of enclosures at times t = 0 (June 1990), 5, 14, 30, 60, 90, and 400 d; tissue concentrations of metallothionein (MT) and metals were monitored over time. Measurements on control molluscs enclosed in their lake of origin showed that enclosure per se had no apparent effect on tissue [MT] or tissue metal levels, but did decrease shell growth. Metallothionein levels in specimens transplanted to the more contaminated lake showed a slow but steady increase with time; in contrast, MT levels in the control populations showed only modest seasonal fluctuations. The increase in MT over time in the transplanted bivalves was closely correlated with a similar slow increase in soft tissue [Cd]. We conclude that MT in the freshwater bivalve P. grandis is a promising biochemical indicator of metal exposure.

Changes in subcellular metal partitioning in the gills of freshwater bivalves (Pyganodon grandis) living along an environmental cadmium gradient

1999 ◽  
Vol 56 (5) ◽  
pp. 774-784 ◽  
Author(s):  
Dacheng Wang ◽  
Yves Couillard ◽  
G C Campbell ◽  
Pierre Jolicoeur
Keyword(s):  
Mining Area ◽  
Size Exclusion ◽  
Metal Exposure ◽  
Relative Molecular Mass ◽  
Biological Organization ◽  
Freshwater Bivalve ◽  
Exclusion Chromatography ◽  
Saturation Method ◽  
Pyganodon Grandis ◽  
Different Levels

To test the response of the freshwater bivalve Pyganodon grandis to increased metal exposure in the field, specimens were collected from 10 lakes located along a known metal gradient in a mining area in northwestern Québec. Total gill concentrations of metallothionein (MT) were determined by the 203Hg saturation method for molluscs from each lake, and the distribution of Cd among various cytosolic ligands, including MT, was determined by size-exclusion chromatography. Gill MT concentrations responded to environmental exposure to Cd but not to Cu or Zn exposure; these spatial variations along the Cd gradient were more important than the seasonal summer variations in gill MT concentrations. Bivalves exposed to concentrations of dissolved free Cd2+ higher than ~1 nM in the external medium exhibited a marked increase of Cd in the low relative molecular mass ligand pool. Symptoms of toxic effects at different levels of biological organization were associated with this biochemical anomaly.

Field transplantation of a freshwater bivalve, Pyganodon grandis, across a metal contamination gradient. II. Metallothionein response to Cd and Zn exposure, evidence for cytotoxicity, and links to effects at higher levels of biological organization

1995 ◽  
Vol 52 (4) ◽  
pp. 703-715 ◽  
Author(s):  
Y. Couillard ◽  
P. G. C. Campbell ◽  
J. G. Auclair ◽  
J. Pellerin-Massicotte
Keyword(s):  
Gill Tissue ◽  
Weight Fraction ◽  
Condition Index ◽  
Mining Area ◽  
Low Molecular Weight ◽  
Biological Organization ◽  
Freshwater Bivalve ◽  
Cellular Toxicity ◽  
Pyganodon Grandis ◽  
Anodonta Grandis

To examine links between the metallothionein (MT) status of an organism and its general health, we transplanted adult specimens of the freshwater bivalve Pyganodon grandis (formerly Anodonta grandis) from a less to a more contaminated lake in the mining area of Rouyn-Noranda, in northwestern Québec. The transplanted bivalves were maintained in open enclosures placed in the bottom sediments of the contaminated lake; in addition, indigenous specimens were maintained in control enclosures in their lake of origin. Up to 16 individuals were removed from pairs of enclosures at times t = 0 (June 1990), 5, 14, 30, 60, 90, and 400 d. Excised gill tissue was analyzed for metallothionein, Cd, Cu, Zn, Ca, and malondialdehyde (MDA), a product of lipid peroxidation. Metal partitioning in the gill cytosol, as determined on a subset of gill samples from transplanted molluscs, changed markedly during the experiment. After 400 d, Cd was present in the low molecular weight fraction of the gill cytosol, and symptoms of cellular toxicity were detected in the transplanted molluscs (elevated [MDA] and [Ca]). At the whole organism level, the marked transplanted bivalves grew more slowly over the 400-d experiment than did marked control bivalves in Lake Opasatica, and their condition index deteriorated over time.

The Migration-Crime Nexus and the Press in France, Germany, and the United Kingdom

2018 ◽  
Vol 15 (2) ◽  
pp. 167-181
Author(s):  
Alexander A Caviedes
Keyword(s):  
United Kingdom ◽  
Human Trafficking ◽  
Organized Crime ◽  
Steady Increase ◽  
Press Coverage ◽  
Individual Country ◽  
The United Kingdom ◽  
The Press ◽  
And Migration ◽  
Over Time

This article explores the link between migrants and crime as portrayed in the European press. Examining conservative newspapers from France, Germany, and the United Kingdom from 2007 to 2016, the study situates the press coverage in each individual country within a comparative perspective that contrasts the frequency of the crime narrative to that of other prominent narratives, as well as to that in the other countries. The article also charts the prevalence of this narrative over time, followed by a discussion of which particular aspects of crime are most commonly referenced in each country. The findings suggest that while there has been no steady increase in the coverage of crime and migration, the press securitizes migration by focusing on crime through a shared emphasis on human trafficking and the non-European background of the perpetrators. However, other frames advanced in these newspapers, such as fraud or organized crime, comprise nationally distinctive characteristics.

Daily and annual shell growth in a long-lived freshwater bivalve as a proxy for winter snowpack

2021 ◽  
pp. 110346
Author(s):  
Tsuyoshi Watanabe ◽  
Mayumi Suzuki ◽  
Yoshihiko Komoto ◽  
Kotaro Shirai ◽  
Atsuko Yamazaki
Keyword(s):  
Shell Growth ◽  
Freshwater Bivalve

scholarly journals Incidence, Characteristics, and Prognosis of Incidentally Discovered Hepatocellular Carcinoma after Liver Transplantation

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Walid El Moghazy ◽  
Samy Kashkoush ◽  
Glenda Meeberg ◽  
Norman Kneteman
Keyword(s):  
Hepatocellular Carcinoma ◽  
Liver Transplantation ◽  
Tumor Recurrence ◽  
Patient Survival ◽  
Steady Increase ◽  
Liver Transplants ◽  
Significant Difference ◽  
One Year ◽  
Over Time

Background. We aimed to assess incidentally discovered hepatocellular carcinoma (iHCC) over time and to compare outcome to preoperatively diagnosed hepatocellular carcinoma (pdHCC) and nontumor liver transplants.Methods.We studied adults transplanted with a follow-up of at least one year. Patients were divided into 3 groups according to diagnosis of hepatocellular carcinoma.Results.Between 1990 and 2010, 887 adults were transplanted. Among them, 121 patients (13.6%) had pdHCC and 32 patients (3.6%) had iHCC; frequency of iHCC decreased markedly over years, in parallel with significant increase in pdHCC. Between 1990 and 1995, 120 patients had liver transplants, 4 (3.3%) of them had iHCC, and only 3 (2.5%) had pdHCC, while in the last 5 years, 263 patients were transplanted, 7 (0.03%) of them had iHCC, and 66 (25.1%) had pdHCC (P<0.001). There was no significant difference between groups regarding patient survival; 5-year survival was 74%, 75.5%, and 77.3% in iHCC, pdHCC, and non-HCC groups, respectively (P=0.702). Patients with iHCC had no recurrences after transplant, while pdHCC patients experienced 17 recurrences (15.3%) (P=0.016).Conclusions.iHCC has significantly decreased despite steady increase in number of transplants for hepatocellular carcinoma. Patients with iHCC had excellent outcomes with no tumor recurrence and survival comparable to pdHCC.

scholarly journals Long-Term Trends in News Content

2019 ◽  
Author(s):  
Edda Humprecht ◽  
Linards Udris
Keyword(s):  
International Comparisons ◽  
Organizational Level ◽  
Steady Increase ◽  
Theoretical Concepts ◽  
News Content ◽  
National Differences ◽  
Long Term Trends ◽  
Over Time ◽  
The Way

The way news is produced and consumed has changed dramatically during the first two decades of the 21st century due to digitalization and economic pressures. In a globalized world, current events are reported in almost real time in various countries and are diffused rapidly via social media. Thus much scholarly attention is devoted to determining whether these developments have changed news content. Comparative research in the area of journalism focuses on whether news content across countries converges over time and to what degree national differences persist across countries. When studying the research on long-term trends in news content, three main observations can be made. First, theoretical assumptions are often rooted in different models of democracies, but they are rarely explicitly discussed. Second, many studies focus on the organizational level using theoretical concepts related to increased market orientation of news outlets, such as personalization, emotionalization, or scandalization. Furthermore, commercialization is associated with the effects of digitalization and globalization, namely, decreased advertising revenues and increased competition. A commonly expressed fear is that these changes have consequences for democracy and informed citizenship. Third, in recent years, there has been a steady increase of studies employing international comparisons as well as a growing standardization for measurements. These developments lead to more multicountry studies based on large samples but come at the expense of more fine-grained analysis of the way news content changes over time. Finally, the vast majority of cross-national and single-country studies focus on Western democracies. Thus our knowledge about recent changes in news content is limited to a small set of countries. Overall, many studies provide evidence for constant changes of news content driven by social, political, and economic developments. However, different media systems exhibit a sustained resilience toward transnational pressures reflected in a persistence of national differences in news content over time.

Sub-cellular partitioning of metals (Cd, Cu, Zn) in the gills of a freshwater bivalve, Pyganodon grandis: role of calcium concretions in metal sequestration

2005 ◽  
Vol 71 (4) ◽  
pp. 319-334 ◽  
Author(s):  
Emmanuelle Bonneris ◽  
Anik Giguère ◽  
Olivier Perceval ◽  
Thierry Buronfosse ◽  
Stéphane Masson ◽  
...  
Keyword(s):  
Freshwater Bivalve ◽  
Metal Sequestration ◽  
Pyganodon Grandis

scholarly journals Bird Feces as Indicators of Metal Pollution: Pitfalls and Solutions

Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 124
Author(s):  
Tapio Eeva ◽  
Nelli Raivikko ◽  
Silvia Espín ◽  
Pablo Sánchez-Virosta ◽  
Suvi Ruuskanen ◽  
...  
Keyword(s):  
Dietary Exposure ◽  
Mean Value ◽  
Metal Exposure ◽  
Short Time Scale ◽  
Bird Droppings ◽  
Metal Levels ◽  
Mass Proportion ◽  
Exposure Levels ◽  
Short Time ◽  
Bird Feces

Bird feces are commonly used as a proxy for measuring dietary metal exposure levels in wild populations. Our study aims to improve the reliability and repeatability of fecal metal measurements and gives some recommendations for sampling. First, we studied levels of variation in metallic element (arsenic, calcium, cadmium, cobalt, copper, nickel, lead) concentrations: temporal variation within an individual, among siblings in a brood and among-brood/spatial variation. Second, we explored the variation caused by dual composition (urate vs. feces) of bird droppings. Two sets of fresh fecal samples were collected from pied flycatcher (Ficedula hypoleuca) nestlings living in a metal polluted area in summers 2017 (dataset 1) and 2018 (dataset 2). We found a great deal of temporal intra-individual variation in metal levels, suggesting that dietary exposure varied markedly in a short time scale (within a day). A sample from only one nestling per brood did not well describe the brood mean value, and we recommend that at least four siblings should be sampled. Brood level samples give relatively good temporal repeatability for most metals. For all the metals, the levels in the fecal portion were more than double to those in the urate portion. Since the mass proportion of urate in the bird droppings varied a great deal among samples, standardizing sampling, e.g., by collecting only the fecal part, would markedly reduce the variation due to composition. Alternatively, urate portion could be used for biomonitoring of internally circulated bioavailable metal.

Trajectories of Injectable Cancer Drug Costs After Launch in the United States

2018 ◽  
Vol 36 (4) ◽  
pp. 319-325 ◽  
Author(s):  
Noa Gordon ◽  
Salomon M. Stemmer ◽  
Dan Greenberg ◽  
Daniel A. Goldstein
Keyword(s):  
Drug Administration ◽  
Food And Drug Administration ◽  
The United States ◽  
Drug Costs ◽  
Cancer Drug ◽  
Steady Increase ◽  
Drug Prices ◽  
The Us ◽  
The Mean ◽  
Over Time

Purpose Cancer drug prices at launch have increased in recent years. It is unclear how individual drug prices change over time after launch and what market determinants influence these changes. We measured the price trajectories of a cohort of cancer drugs after their launch into the US market and assessed the influence of market structure on price changes. Methods We studied the changes in mean monthly costs for a cohort of 24 patented, injectable anticancer drugs that were approved by the US Food and Drug Administration between 1996 and 2012. To account for discounts and rebates, we used the average sales prices published by the Centers for Medicare and Medicaid Services. Costs were adjusted to US general and health-related inflation rates. For each drug, we calculated the cumulative and annual drug cost changes. We then used a multivariable regression model to evaluate the association between market and cost changes over time. Results With a mean follow-up period of 8 years, the mean percent change in cost for all drugs was +25% (range, −14% to +96%). After adjusting for inflation, the mean cost change was +18% (range, −16% to +59%). Rituximab and trastuzumab followed a similar pattern in cost increases over time, and the inflation-adjusted monthly costs rose since approval by 49% and 44%, respectively. New supplemental US Food and Drug Administration approvals, new off-label indications, and new competitors did not influence the annual cost change rates. Conclusion Anticancer drug costs may change substantially after launch. Regardless of competition or supplemental indications, there is a steady increase in costs of patented anticancer agents over time. New regulations may be needed to prevent additional increases in drug costs after launch.

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