Bioaccumulation and toxicity of aluminium in the pond snail at neutral pH

2000 ◽  
Vol 51 (2-4) ◽  
pp. 309-316 ◽  
Author(s):  
Cathy R. McCrohan ◽  
M. M. Campbell ◽  
R. Jugdaohsingh ◽  
S. Ballance ◽  
J. J. Powell ◽  
...  
Keyword(s):  
2000 ◽  
Vol 57 (6) ◽  
pp. 1151-1159 ◽  
Author(s):  
Morag M Campbell ◽  
Keith N White ◽  
Ravin Jugdaohsingh ◽  
Jonathan J Powell ◽  
Catherine R McCrohan

A major factor influencing the toxicity of Al at neutral pH is the presence of complexing ligands. This study compared the effect of exposure to aluminum nitrate, aluminum lactate, and aluminum maltol, in the presence or absence of monomeric silica (Si), on the behaviour of the pond snail Lymnaea stagnalis. Concentrations of Al and Si used were similar to those found in the natural environment. Soluble Al concentration in the water fell significantly with time over 48 h following addition as the nitrate or lactate (500 μg·L-1), presumably owing to polymerisation as the colloidal hydroxide. This loss was enhanced by the presence of snails or Si (Al:Si = 1:15). Aluminum maltol largely remained in solution. Snails exposed to all three Al compounds showed depression of behavioural activity after 7 days; this effect was ameliorated in the presence of higher (Al:Si = 1:15) but not lower (Al:Si = 1:1) concentrations of Si. Depression of feeding behaviour occurred with all three Al compounds, although it was delayed in the presence of aluminum maltol. Expression of conditioned feeding was inhibited in snails exposed to aluminum nitrate during training and testing. The behavioural changes are likely to be mirrored in the field, with adverse consequences for the "fitness" of natural populations.


1995 ◽  
Vol 52 (8) ◽  
pp. 1623-1629 ◽  
Author(s):  
R. Truscott ◽  
C. R. McCrohan ◽  
S. E. R. Bailey ◽  
K. N. White

Time-lapse video was used to examine the effect of short- (19 h) and long-term (1 year) exposure to Al or Pb at neutral pH in static water conditions on the total distance moved by the freshwater snail Lymnaea stagnalis. Aluminium at 100, 200, 500, or 1000 μg∙L−1 normally depressed and Pb at 50 and 200 μg∙L−1 often increased activity over the first 19 h of exposure. Smaller (younger) snails generally showed greater sensitivity to Al. Exposure to 100 or 500 μg Al∙L−1 for up to 30 days caused hyperactivity, but thereafter and 1 year later, activity was similar to controls, suggesting that the snails had become tolerant. Lead (200 μg∙L−1) caused continued hyperactivity for up to 50 days, although movement was significantly reduced after 1 year, suggesting that acclimation had occurred. The effect of Al is interesting given the supposed limited bioavailability of this metal at neutral pH.


Author(s):  
J. P. Robinson ◽  
P. G. Lenhert

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.


1992 ◽  
Vol 67 (01) ◽  
pp. 126-130 ◽  
Author(s):  
Olivier Spertini ◽  
Jacques Hauert ◽  
Fedor Bachmann

SummaryPlatelet function defects observed in chronic alcoholics are not wholly explained by the inhibitory action of ethanol on platelet aggregation; they are not completely reproduced either in vivo by short-term ethanol perfusion into volunteers or in vitro by the addition of ethanol to platelet-rich plasma. As acetaldehyde (AcH) binds to many proteins and impairs cellular activities, we investigated the effect of this early degradation product of ethanol on platelets. AcH formed adducts with human platelets at neutral pH at 37° C which were stable to extensive washing, trichloracetic acid hydrolysis and heating at 100° C, and were not reduced by sodium borohydride. The amount of platelet adducts formed was a function of the incubation time and of the concentration of AcH in the reaction medium. At low AcH concentrations (<0.2 mM), platelet bound AcH was directly proportional to the concentration of AcH in the reaction medium. At higher concentrations (≥0.2 mM), AcH uptake by platelets tended to reach a plateau. The amount of adducts was also proportional to the number of exposures of platelets to pulses of 20 pM AcH.AcH adducts formation severely impaired platelet aggregation and shape change induced by ADP, collagen and thrombin. A positive correlation was established between platelet-bound AcH and inhibition of aggregation.SDS-PAGE analysis of AcH adducts at neutral pH demonstrated the binding of [14C]acetaldehyde to many platelet proteins. AcH adduct formation with membrane glycoproteins, cytoskeleton and enzymes might interfere with several steps of platelet activation and impair platelet aggregation.This in vitro study shows that AcH has a major inhibitory action on platelet aggregation and may account for the prolonged ex vivo inhibition of aggregation observed in chronic alcoholics even in the absence of alcoholemia.


1964 ◽  
Vol 11 (01) ◽  
pp. 075-084 ◽  
Author(s):  
Daniel L Kline ◽  
Jacob B Fishman ◽  

Summary1. Lysine increased the solubility, decreased the SK requirement and increased the stability of plasmin prepared from purified plasminogen by SK activation.2. A procedure is presented for the rapid and quantitative conversion of plasminogen to plasmin and storage of the plasmin in stable form at neutral pH as a lyophilized powder.3. Approximately 10% for the plasminogen molecule was split off during its activation. No carbohydrate was lost.4. The plasmin isolated was homogeneous in the ultracentrifuge at pH 2.5 and was quantitatively convertible to plasminogen activator by the addition of SK.


1979 ◽  
Vol 42 (02) ◽  
pp. 726-733 ◽  
Author(s):  
Utako Okamoto ◽  
Jun-ichiro Yamamoto ◽  
Yoko Nagamatsu ◽  
Noboru Horie

SummaryProtease-like activity which split plasminogen-free fibrin was demonstrated in 2 M KSCN extracts of the lung and spleen of conventional rats. The activity was virtually undetectable in tissue extracts from germ-free rats. The extracts from the conventional rat tissues split fibrin and fibrinogen remarkably at neutral pH, but not casein, when examined using fibrin, fibrinogen-agar and casein-agar plates. The fibrinolytic activity was inhibited by STI and DFP, indicating a serine protease nature. The activity was not inhibited by TLCK, t-AMCHA or dansyl-L-arginine-methylpiperidine amide (a selective synthetic thrombin inhibitor, OM189). It was neither activated nor inhibited by cysteine, KCN or iodoacetic acid. The results obtained indicate that the protease-like activity of the lung and spleen extracted with 2 M KSCN from conventional rats has properties which differ from those of trypsin, plasmin, plasminogen-activator, thrombin, and cathepsin A, B and C.


2018 ◽  
Vol 12 (2) ◽  
pp. 108-116
Author(s):  
A.M. Ustinov ◽  
R.T. Safiullin ◽  
R.R. Safiullin

Information is provided on the causative agents of fasciolosis and the developmental biology of Fasciola hepatica. Fasciolosis of cattle is widespread in the conditions of the Kaluga Region and the Central Federal District on farms of different forms of ownership. The greatest number of F. hepatica eggs in 1 g of feces in cattle is established in JSC "Iskra" - 175,4 specimens, the lowest - in the samples from cows from private farms - 87,6 sp. At the opening slaughter of cattle at meat processing plants region and slaughterhouses invasion of their fasciolae was 34.8%. The average number fascial one infected animal was 32.1 specimens, including adult - and larval specimens of 25.2 and 6.9 copies At veterinary-sanitary expertise and helminthological autopsy of the liver, gallbladder and bile ducts installed year-round invasion fasciolae mainly in the adult stage. Young animals of the current year are infected with fasciola in the pasture massly in August-September, and the extent of invasion in November was 4.3%, for winter-stabling months an average of 12.6%, in March - 17.9% and in April after de-worming - 5.9%.The data obtained in the study of the distribution of the small pond has shown that in the Kaluga region these mollusks are widespread. In this case, the invasion of the small pond snail by larval forms of fasciolae in different years has its own peculiarities, which are influenced by climatic factors.The different dosage forms of clozantel - Rolenol and Santel and Genamectin with mixed fascioliasis and hypodermatosis of bovine in the recommended dose against subcutaneous gadfly larvae - provided 100% efficacy. The tested dosage forms of clozantel are similar in effectiveness against subcutaneous gadfly larvae (EE-100%) and fasciol (EE-95 and 90%, IE-97.4 and 96.3%).The therapeutic and economic effectiveness of complex domestic preparations of Helmicide and Fascocida in spontaneous fascioliasis of cattle is studied.


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