Comparison of Trace Element Concentrations Between Chick and Adult Black-Tailed Gulls (Larus crassirostris)

Lead (Pb) in the tissues of Anatidae, Ardeidae, Sternidae and Laridae of the Northern Hemisphere: a review of environmental studies

Due to the ability of birds to travel long distances in the air, the potential feeding area of each individual is much larger than that of typical terrestrial animals. This makes birds a convenient indicator of environmental lead (Pb) pollution over large areas, in particular areas of inland and coastal waters. The aim of this study was to assess the concentrations of Pb in various organs of water birds from a variety of locations. The focus was on ducks, geese and swans (Anatidae); herons and egrets (Ardeidae); terns (Sternidae); and gulls (Laridae). This article describes the level of lead in the most commonly studied tissue types: feathers, bones and the liver. The study also presents data concerning the concentration of lead in the eggs of water birds. The highest levels of lead pollution can be observed in China and Korea, related to their high level of industrialization. In Iran too, environmental lead pollution is high, likely due to the developed petrochemical industry. Lead pollution in Japan, as well as in Western European countries (Spain, France, Italy), seems to be much lower than in China, India or Iran. Nevertheless, the level of pollution in Europe is higher than satisfactory, despite the introduction of a number of bans related to, for example, the use of leaded petrol or lead-containing paints. Finally, the USA and Canada appear to be the areas with the lowest lead pollution, possibly due to their low population densities.

Trace elements in feathers and eggshells of brown booby Sula leucogaster in the Marine National Park of Currais Islands, Brazil

Levels of trace elements were investigated in feathers of 51 adults and 47 eggshells of brown boobies Sula leucogaster from one bird colony in the Marine National Park of Currais Islands, Brazil, between December 2013 and October 2014. Average concentrations (μg g^-1, dry weight) in feathers and eggshells, respectively, were Al 50.62-9.58, As 0.35-2.37, Cd 0.05-0.03, Co 0.38-2.1, Cu 15.12-0.99, Fe 47.47-22.92, Mg 815.71-1116.92, Ni 0.29-11.85, and Zn 94.16-1.98. In both arrays, the average concentration of Mg was the highest among all the elements analyzed, while the lowest was recorded for Cd. As and Ni presented levels at which biological impacts might occur. Zn concentrations were higher than those considered normal in other organs. Levels of Al, Fe, Cu, Zn, and Cd were higher in feathers, whereas higher contents of Mg, Co, Ni, and As occurred in eggshells. The comparison between the elements in eggshells collected at different seasons showed no significant difference (p > 0.05) due, probably, to the lack of temporal variation on foraging behavior and/or on bioavailability of trace elements. Metals and arsenic in feathers and eggshells were mostly not correlated. Future studies on Paraná coast should focus on the speciation of the elements, especially As, Ni, and Zn, which proved to be a possible problem for the environment and biota. It is necessary to investigate both matrices, shell and internal contents of the eggs, in order to verify if the differences previously reported in other studies also occur in eggs of brown boobies in the Marine National Park of Currais Islands.

Concentrations of Trace Elements in Adult and Nestling Black-Tailed Gulls (Larus crassirostris)

Trace element concentrations (Cd, Pb, Cr, Al, Cu, Mn, Zn and Fe) were measured in the liver of black-tailed gull (Larus crassirostris) adults (n = 10) and nestlings (n = 10) collected at Chilsando Island, Jellanam-do, Korea, in June 2011. Adults gulls, when compared to nestlings, accumulated higher concentrations of all trace elements; Cd, 0.53 and 0.04 µg/g dry weight (dw), respectively, Pb, 0.47 and 0.21 µg/g dw, Cr, 0.08 and 0.05 µg/g dw, Al, 6.56 and 3.94 µg/g dw, Cu, 5.57 and 3.88 µg/g dw, Mn, 3.71 and 1.99 µg/g dw, Zn, 34.1 and 22.9 µg/g dw and Fe, 279 and 171 µg/g dw. No individuals of either adults or nestlings exceeded the threshold level for toxic effects for Cd (>3.0 µg/g dw), Pb (>6.0 µg/g dw) and Cr (>4.0 µg/g dw). Cd, Pb and Cr concentrations were comparable or lower than reported in other gull studies worldwide. None of the other elements present in the liver of black-tailed gull adults and nestlings were at toxic levels.

Pygoscelis antarcticus feathers as bioindicator of trace element risk in marine environments from Barton Peninsula, 25 de Mayo (King George) Island, Antarctica

We report the contents of elements in feathers of Chinstrap penguin (Pygoscelis antarcticus), which had not been informed up to now, such as silver and bromine and others listed as hazardous by the United States Environmental Protection Agency as arsenic, cobalt, chromium, and mercury. Analyses of the element concentrations in feathers, adult and chicken, from Barton Peninsulas at 25 de Mayo (King George) Island, South Shetlands, were made by Instrumental Neutron Activation Analysis. Samarium, lanthanum a, thorium, and uranium concentrations in Chinstrap penguin feathers were below 0.1 mg/kg. This suggests that the elements in feather do not come from atmospheric particles surface deposition. Arsenic (0.120 ± 0.050 mg/kg) and cobalt (0.030 ± 0.020 mg/kg) concentrations were lower than the reports for other colony of Chinstrap penguins, and essential elements as iron (26 ± 12 mg/kg), zinc (78.0 ± 5.3 mg/kg), and chromium (0.51 ± 0.27 mg/kg) were in the same range while Se (2.90 ± 0.65 mg/kg) content were the lowest reported. Mercury (0.43 ± 0.21 mg/kg), chromium (0.210 ± 0.060 mg/kg), and silver (0.083 ± 0.003 mg/kg) in chicks tended to be lower than in adults. Iron, cobalt, and arsenic concentrations in feathers found in this study were the lowest compared to measurements were in several penguin species in Antarctica. These results confirm to feathers like effective indicators for the trace elements incorporated in the penguins and it provide a data set which can adds to the baseline for bioindication studies using feathers.

Molecular mechanisms of megakaryopoiesis

One function of bone marrow megakaryocytes (MKs) is the controlled release of platelets into the circulation. Over the past few years, molecular mechanisms that contribute to MK development and differentiation have begun to be elucidated. This review provides a brief overview of megakaryopoiesis and platelet function, and the importance of selected hematopoietic transcription factors (including GATA-1, FOG, Fli-1, AML1, and NF-E2) and target genes in this biological process. In addition, a discussion of human diseases affecting megakaryopoiesis and mouse models of thrombocytopenia are presented with emphasis on how these systems have and will continue to provide further insights into mechanisms that control the biological functions of the megakaryocytic cell lineage. Ultimately, such knowledge may provide the basis for novel therapeutic approaches for modulation of platelet number and function.