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  • 1
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Once the moult patterns have been taken into account, feather methylmercury levels can be used to accurately measure the mercury burdens of seabirds. We used body feathers from live seabirds and from museum collections to examine geographical and temporal patterns of mercury contamination in the North Sea. This approach identifies an increase in mercury concentrations in seabirds of the German North Sea coast during the last 100 years, especially high levels during the 1940s, and reduced contamination in the last few years. Comparisons among populations suggest that some increases in mercury levels are predominantly due to local pollution inputs, as on the German coast, while in other areas deposition from jet stream circulation of global contamination may be the major contributor. Mercury levels are far higher in seabirds from the German North Sea coast than in populations from the north and west North Sea or from most areas of the North Atlantic. We advocate the use of museum collections of birds for studies of long-term changes in levels of mercury contamination.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of ornithology 135 (1994), S. 508-512 
    ISSN: 1439-0361
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1569-8041
    Keywords: docetaxel in unknown primary ; therapy of unknown primary cancer ; unknown primary cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose:To evaluate the toxicity, response rate and short-termsurvival associated with the chemotherapy combinations of docetaxel pluscisplatin or carboplatin when used for the treatment of patients withmetastatic carcinoma of unknown primary site. Patients and methods:Twenty-six patients were treated withdocetaxel 75 mg/m2 i.v. and cisplatin 75 mg/m2 i.v.given every three weeks (study A) and subsequently, 47 patients were treatedwith docetaxel 65 mg/m2 and carboplatin (AUC dose = 6) every threeweeks (study B). Stable or responding patients received a maximum of eightcourses of therapy. Patients who were known to be in treatable subset groupswere excluded from these trials. The majority of patients had two or moresites of metastasis; about 45% had adenocarcinoma and 50% poorlydifferentiated carcinoma. Results:In study A, 6 of 23 (26%) assessable patients hada major response to therapy. The median survival was eight months and one-yearsurvival 42%. Seven patients were removed from the study early forgrade 3 or 4 nausea and vomiting. In study B, 9 of 40 assessable patients(22%) had a major response to therapy. Median survival was eight monthsand one-year survival 29%. Toxicity associated with this regimen waspredominantly myelosuppression. Comparisons of the two sequential trialsshowed no differences in response rates or survivals (P = 0.75). Conclusions:Docetaxel and cisplatin (study A) is an activecombination in carcinoma of unknown primary site, but associated withsubstantial gastrointestinal toxicity. A combination of docetaxel pluscarboplatin (study B) is better tolerated and produced a similar responserate, median survival and one-year survival. Comparative phase III trials willbe necessary to unequivically prove a survival advantage for any form oftherapy in these patients. However, the survival for patients with carcinomaof unknown primary site receiving docetaxel-based chemotherapy is comparableto the survivals for several other groups of advanced cancer patients, suchas non-small cell lung cancer, receiving various types of chemotherapy.
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  • 4
    ISSN: 1439-1104
    Keywords: Ascaris suum ; nematode ; nematode peptides ; inhibitory neuropeptides ; FMRFamide-related peptides (FaRPs) ; myoactivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A large number of FMRFamide-related peptides (FaRPs) are found in nematodes, and some of these are known to influence tension and contractility of neuromuscular strips isolated fromAscaris suum body wall. Relaxation of these strips has been noted with five nematode FaRPs. The inhibitory actions of SDPNFLRFamide (PF1) and SADPNFLRFamide (PF2) appear to be mediated by nitric oxide, as previously demonstrated with inhibitors of nitric oxide synthase (NOS). This present study showed that the effects of PF1 were also dependent on external Ca++ and were reduced by the Ca++-channel blocker verapamil, observations consistent wirh the finding that nematode NOS is Ca++-dependent. KSAYMRFamide (PF3), KPNFIRFamide (PF4) and KNAFIRFamide (an alanine substituted analog of KNEFIRFamide, AF1, termed A3AF1) also relaxed A.suum muscle strips, but these responses were not affected by NOS inhibitors. PF3 inhibited the activity of strips prepared from the dorsal side of the worm, but contracted ventral strips. Both effects were dependent on the presence of ventral/dorsal nerve cords (unlike PF1/PF2) and were attenuated in medium which contained high K+ or low Ca++. PF4-induced muscle relaxation and hyperpolarization were independent of nerve cords, but were reversed in Cl-free medium, unlike PF1 or PF3. The PF4 effect physiologically desensitized muscle strips to subsequent treatment with PF4 and/or GABA. However, PF4 and GABA were not synergistic in this preparation. The effects of GABA, but not PF4, were reduced in muscle strips treated with the GABA antagonist, NCS 281-93. Following PF4 (or GABA) relaxation, subsequent treatment with higher doses of PF4 caused muscle strip contraction. A3AF1 was found to relax muscle strips and hyperpolarize muscle cells independently of the ventral and dorsal nerve cords, K+, Ca++, and Cl-, and mimicked the inhibitory phase associated with the exposure of these strips to AF1. On the basis of anatomical and ionic dependence, these data have delineated at least four distinct inhibitory activities attributable to nematode FaRPs. Clearly, a remarkably complex set of inhibitory mechanisms operate in the nematode neuromuscular system.
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  • 5
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Histamine concentration-response curves performed on isolated airways smooth muscle preparations were unaffected by threshold constrictor concentrations of LTD4 (194±34 pM for parenchymal strips and 1940±480 pM for isolated trachea, respectively). In contrast, LTD4, when administered between 2 and 60 s beforehand, potentiated bronchoconstrictor responses to histamine in anaesthetized, artificially ventilated guinea-pigs. Doses of LTD4, which did not produce direct effects on airways resistance, potentiated histamine-induced bronchoconstriction to a lesser degree than those having small direct effects. This potentiation was prevented by bilateral vagotomy. In addition, the antagonists atropine (100 μg/kg), FPL55712 (5 mg/kg) and indomethacin (1 mg/kg) effectively prevented the interaction. It is suggested that the interaction between LTD4 and histamine involves a specific leukotriene receptor, possibly linked to the generation of a cyclo-oxygenase metabolite and requires intact cholinergic innervation of airways smooth muscle. Furthermore, these results are consistent with the hypothesis that LTD4 may be a mediator of bronchial hyperreactivity.
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  • 6
    ISSN: 1420-9071
    Keywords: Arylsulfatase A ; arylsulfatase B ; 4-methylumbelliferyl sulfate ; rodent ; bovine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rodent and bovine arylsulfatase B hydrolyze 4-methylumbelliferyl sulfate (4MUS) 10- to 30-fold more efficiently than arylsulfatase A. Therefore, 4MUS grossly underestimates arylsulfatase A activity in the presence of excess arylsulfatase B.
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  • 7
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Leukotriene D4 (LTD4, 0.1–0.5 μg/kg, i.v.), administered 20 s before histamine (H, 1–4 μg/kg, i.v.), enhanced the bronchoconstrictor response to H by between 105 and 168%. Bilateral vagotomy, atropine or indomethacin each attenuated, whereas hexamethonium completely prevented, this enhancement. LTD4 failed to enhance the bronchoconstrictor effects of either acetylcholine (ACh) or electrical stimulation of the vagi. Capsaicin pretreatment reduced bronchoconstrictor responses to electrical stimulation of the vagi, but did not affect depressor responses. There was no interaction between LTD4 and H on bronchomotor tone in capsaicin-pretreated guinea-pigs. It is concluded that LTD4 enhances H-induced bronchoconstriction by a mechanism which involves an increased activity of efferent cholinergic nerves innervating the airways. However, the failure of LTD4 to enhance bronchoconstriction due to ACh or vagal stimulation, together with the prevention of the interaction between LTD4 and H by capsaicin-pretreatment, suggests that the site of the interaction may be on capsaicin-sensitive afferent neurones.
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  • 8
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract Copper and cadmium concentrations were monitored in a population of the grasshopperChorthippus brunneus in grasslands in and around a copper refinery. Total body copper and cadmium concentrations increased with site contamination levels from control to highly contaminated refinery site environments. Refinery site grasshoppers accumulated both metals throughout the summer and autumn reaching a peak concentration of 1,600 μg/g for copper. The seasonal pattern of accumulation of copper and cadmium closely followed seasonal trends in metal contamination levels in the indigenous vegetation, particularlyAgrostis stolonifera. Copper accumulated progressively through the developmental instars ofC. brunneus. However, there was evidence of copper exclusion during the final moult. This may be linked to copper compartmentalization in the integument of the later instars. Metals were not evenly distributed within the grasshopper body; 85% of total body copper and cadmium is associated with the integument.
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  • 9
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract Total mercury concentrations were determined in samples of body feathers from a range of common seabird species breeding at L»trabjarg, northwest Iceland, St. Kilda, Foula and the Firth of Forth, Scotland and Bleiksøy, Syltefjord, and Hornøy, Norway. Seabirds from L»trabjarg generally exhibited the highest mercury concentrations, with a trend of decreasing mercury concentrations in a southwest to northeast direction in seabirds at the other colonies; seabirds at Hornøy were generally found to have the lowest mercury concentrations. Some species at the Firth of Forth exhibited relatively elevated mercury concentrations compared to those at Foula and Norwegian sites. Inter-colony differences in diet were thought to be relatively small for most species and unlikely to account for the range of mercury concentrations measured in the seabirds (L»trabjarg: lowest arithmetic mean mercury concentration in common guillemots Uria aalge, 1.6 μg/g, s.d.=0.6, n=45; highest arithmetic mean mercury concentration in kittiwakes Rissa tridactyla, 5.5 μg/g, s.d.=1.7, n=36). The oceanic transport of mercury, together with the effects of anthropogenic inputs of mercury to the northeast Atlantic, and the removal of mercury from the water column via biological activity are discussed as influential factors determining the observed patterns of mercury concentration in seabirds.
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  • 10
    ISSN: 1432-0703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Notes: Abstract Two field experiments were conducted to assess the predictions of laboratory time-toxicity tests regarding lethal effects of triclopyr butoxyethyl ester (TBEE) on fish in standing and flowing water bodies. Large lake enclosures were treated with TBEE by backpack sprayer at concentrations of 0.25–7.6 mg/L, expressed as acid equivalents. Median dissipation times for TBEE in lake water ranged from 4–8 d.Effects of the treatments on survival and growth of caged rainbow trout were measured. All trout died by 3 d at initial concentrations of 0.69–7.6 mg/L. There was 43% mortality of rainbow trout in the enclosure treated at 0.45 mg/L, and no mortality in the 0.25 mg/L enclosure or the controls. The treatments at the two lower concentrations had significant adverse effects on the growth rates of surviving trout. TBEE was applied to sections of a forest headwater stream at nominal concentrations of 0.8 mg/L and 2.7 mg/L. These concentrations represent maximum-expected environmental concentrations in 50- and 15-cm deep bodies of water, respectively, when directly oversprayed at an application rate of 3.84 kg/ha. Concentrations of TBEE were rapidly dissipated (as much as 70% decline within 55 m) and exposure periods at concentrations above 0.1 mg/L varied from 25 min in the low-concentration area to 55 min in the high-concentration area. The applications of TBEE at both initial test concentrations did not result in any mortality of resident brook trout. There were no significant effects of the herbicide treatments on the growth of 1+ and 2+ brook trout, but there were indications that the growth of 0+ trout was reduced as a result of exposure to TBEE in the stream. These results were in general agreement with the predictions of laboratory time-toxicity tests.
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