Determination of wastewater LC50 of the different process stages of the textile industry.

Textile plants are very important sources of toxic discharges. The purpose of the research described in this paper was to use bioassays with daphnids to determine the LC50 values of textile wastewater samples taken from different stages of the finishing textile industry. Toxicity due to dyeing, chlorination, and the absence of adequate physicochemical conditions for daphnid survival were considered. Wastewater samples corresponding to each process stage were collected at five finishing textile industries and assayed according to previously published procedures. The sensitivity of daphnids to chemicals was assayed using sodium dodecyl sulfate and was similar to other reports (14.6+/-6.8 vs 14.5+/-2.3 mg/L). All effluents from the five company samples were toxic in terms of LC50 and exhibited very high toxicity with acute toxicity unit (ATU) levels between 2.2 and 960, indicating that the five textile industries produced toxic water. The sensory characteristics indicated that the dyes contributed to overall sample toxicity at all process stages. The most toxic contaminant seemed to be ClO- at levels between 0.2 and 6.8 mg/L, suggesting that further research is needed on the economic costs of stage-by-stage and total effluent treatments.

Lead concentration in different compartments of the bovine eye.

It is known that lead is a metabolic substitute of calcium and recently, in vitro results showed that glycosaminoglycans and proteins are capable of binding lead. Therefore, in this work, the level of lead in aqueous humor, vitreous humor, lens and sclera of bovine eyes was analyzed in order to establish a relationship between lead concentration and the contents of glycosaminoglycans, proteins, water and calcium in those structures. Lead was determined by means of atomic absorption spectrometry after acid digestion. Our results suggest a direct relationship between the contents of proteins and glycosaminoglycans, and the ability of the different eye structures to retain lead. Nevertheless, an inverse relationship between water content and lead concentration was found. No association between calcium and lead concentrations was observed.

In vitro lead cation-hyaluronic acid interaction.

It is the purpose of this investigation to study the in vitro spontaneous interaction lead-hyaluronic acid using the equilibrium dialysis technique. The following working conditions were used: membrane retention capacity starting from 12000 D; solvent was an aqueous buffer solution (pH 7.4); relation of internal-external volume of 0.5 : 25 mL: dialysis time 24 hours; lead concentration in dialyzing solution 4 micrograms/mL (always outside the bag); temperature 4 degrees C; concentrations of hyaluronic acid 0.3, 1.2, 2.1 and 3.0 mg/mL; concentration of plasma proteins 1.5 mg/mL; lead was determined in the internal solution of the bag, and was measured quantitatively by atomic absorption spectrometry. Testing separately hyaluronic acid and plasma proteins both types of marcromolecules turned out to bind lead. As the concentration of hyaluronic acid increases, the amount of lead retained increases as well, although this relation is only approximately linear. At the normal concentrations of plasma proteins and hyaluronic acid in synovial fluid, the proteins solution bound more lead than hyaluronic acid solution 16.2 +/- 2.1 and 5.7 +/- 0.4 micrograms/mL respectively (P < 0.0001). What these data show ist that both, hyaluronic acid and proteins are involved in the in vitro lead retention. The effect of both ligands must be synergistic, because when the two molecules are present, a higher amount of lead is retained compared to the amount bound separately, suggesting that lead can replace calcium by complexation with mucopolysaccharides; this explains the lead accumulation in synovial fluid since this fluid is rich in hyaluronic acid and proteins.

Determination of polynuclear aromatic hydrocarbons present in asphaltenes from Mexican oil. A possible environmental risk.

A supercritical fluid extraction and HPLC analysis of the asphaltenes derived from Mexican oil was performed. The aim was to identify potentially mutagenic polynuclear aromatic hydrocarbons present in asphaltenes, since roof waterproofing applications in this country present a significant exposure to hot asphaltene vapors that might conceivably carry such toxic hydrocarbons and therefore pose a health hazard to the workers who apply molten asphaltenes.

Determination of lead in paired samples of blood and synovial fluid of bovines.

Exposure of synovial fluid to lead allows the entrance of this metal into the systemic circulation. In this study we report lead concentrations measured in bovine paired samples of synovial fluid and whole blood withdrawn from the coxo-femoral joints and jugular vein, respectively. Lead was determined by atomic absorption spectrophotometry. This study provides the "normal" values for lead in synovial fluid 12.15 +/- 5.41 and blood 3.54 +/- 1.31 micrograms% (mean +/- SD). The data distribution fits the GAUSSIAN curve (p < 0.02). The difference of concentration between synovial fluid and blood can not be explained only in terms of the solubility of lead in both fluids; other factors must be considered.

Effect of myotonia induced by anthracene-9-carboxylic acid on mitochondrial calcium, plasma creatinine-phosphokinase and aldolase activity in the rat.

The frequent association of myotonia with dystrophy and the knowledge that calcium is increased in injured skeletal muscle cells suggest a possible relationship between cell calcium and myotonic alterations. This investigation has been performed to study the role of calcium in experimental myotonia induced by anthracene-9-carboxylic acid (9-AC) in rats treated with several regimens of food and exercise. Thirty-two rats were divided into 4 groups of 8 rats each, one control and 3 experimental groups. The treatments included caffeine plus exercise (group 2), and a calcium-rich diet (group 3); these procedures were designed to increase intracellular calcium; another group was treated with 9-AC as a myotonia-inducer (group 4). The treatment for all groups lasted 60 days. No significant differences in plasma sodium, potassium, chloride and calcium between control and experimental groups were observed. Whole muscle calcium in wet tissue samples did no change with any treatment. On the contrary, mitochondrial calcium showed a significantly higher concentration in group 3 and 4. CPK and aldolase activities in groups 1, 2 and 3 were similar; but in group 4 these enzyme activities were significantly higher (p less than 0.05). The electrical and mechanical responses were not altered in any rat with any experimental treatment. Our data suggest that myotonia is a predisposing factor for an altered mitochondrial calcium homeostasis in this model; in addition, the enzyme activities of CPK and aldolase were increased in the rats of group 4 implicating that myotonia is a crucial factor in the development of enzymatic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthracene-9-carboxylic acid and haematological and biochemical variables in the rat.

Chronic administration of anthracene-9-carboxylic acid in Long-Evans rats had no significant effect on the following haematological and biochemical variables: haemoglobin, haematocrit, serum sodium, potassium, glucose, cholesterol and proteins. In agreement with previous reports, significant age-related differences of glucose and cholesterol concentration were observed. A decrease of body weight was the main finding. The similarities between the myotonia induced by anthracene-9-carboxylic acid and the characteristic myotonic, haematological and biochemical alterations in patients with myotonia congenita, suggest that, despite untoward effects such as a decrease of body weight, chronic anthracene-9-carboxylic acid administration appears to be a good model for the study of mytonia congenita.

Effect of anthracene-9-carboxylic acid on the renal function of the unanesthetized rabbit.

Anthracene-9-carboxylic acid (9-AC) decreased the conductance to chloride in the isolated thick ascending limb of the loop of Henle and in the isolated perfused frog kidney (Greger, 1984; Oberleithner et al., 1983). The aim of this study was to study the in vivo effects of 9-AC in the unanesthetized rabbit. 9-AC decreased glomerular filtration rate, chloride and sodium clearances and urine volume. While glomerular filtration rate, chloride clearance and urine flow followed similar time courses for decreases and recoveries, and therefore seemed to be related, sodium clearance and fractional excretion of sodium showed an independent time course from the clearance of inulin and remained low throughout the experiment, suggesting a direct tubular effect. Values higher than unity for the fractional excretion of 9-AC, suggest that net tubular secretion of this acid occurs despite 9-AC is bound more than 80% to plasma proteins in the range of 10(-6) to 10(-3) M.

Pharmacokinetics of anthracene-9-carboxylic acid, a potent myotonia-inducer.

The pharmacokinetics of anthracene-9-carboxylic acid (9-AC), a potent myotonia-inducer, was determined in 9 New Zealand White male rabbits after the intravenous injection of 36 microM X kg-1. Myotonic contractions appeared 30 to 80 sec after the beginning of injection. One minute after injection, 25% of the administered dose remains in the blood (9-AC in plasma + 9-AC in cells). Of the 9-AC present in whole blood, 78% is in plasma and can be totally extracted with chloroform whereas the remaining 22% is in the blood cells and can not be extracted. The disappearance of 9-AC from plasma can be explained numerically by assuming an open two-compartment model. By means of a non-linear regression analysis the equation Cp = 20.65e-0.3216t + 28.35e-0.0147t was obtained. This equation gives the best fir for the mean values of all the experiments. The equilibrium between the two compartments is reached in 9.0 min and the Vdss X kg-1 at this time is equal to 273 +/- 18.6 ml X kg-1 which is only marginally larger (10%) than the estimated extracellular volume (246.0 ml X kg-1), suggesting that 9-AC barely penetrates into the cells. The plasma concentration values at t1/2e1 and 3t1/2e1 are 1.07 X 10(-4) M and 2.69 X 10(-5) M, respectively. Similar concentration values were found by other authors as capable of reducing the chloride conductance of skeletal muscle membrane and producing myotonia in vivo and in vitro. Thus, there is a good correspondence between the concentrations active in vitro and the concentrations of plasma in vivo found in this study. Other pharmacokinetic parameters are: t1/2 alpha = 2.8 +/- 0.3 min; t1/2 beta = 45.7 +/- 2.2 min; Area under the curve (AUC) = 1920 +/- 125.0 micrograms X min X ml-1; K12 = 0.085 +/- 0.01 min-1; K21 = 0.162 +/- 0.02 min-1; t1/2e1 = 28.84 +/- 2.2 min., and V1 X kg-1 = 172.1 +/- 9.7 ml. All our findings plus the rapid appearance of myotonic signs and the correspondence with the in vitro studies support the previous assertion that 9-AC acts on the cellular membrane of the skeletal muscles.

Comparison of UV and fluorescence spectrophotometry for the quantification of a potent myotonia inducer: anthracene-9-carboxylic acid, in plasma, urine, and saline perfusion fluids.

UV and fluorescence spectrophotometry were used to establish the analytical profile of a potent myotonia inducer, anthracene-9-carboxylic acid (I). UV spectrophotometry is useful for the determination of I when it is dissolved in physiological solutions (Ringer's, Tyrode's, etc). In these fluids there is a linear relationship between UV absorption and I concentration between 500 and 2000 ng/ml (2.25-9.0 X 10(-6)M). However, in biological fluids there are interferences in the UV absorption due to organic substances. On the other hand, fluorescence spectrophotometry is more sensitive than UV for determinations in plasma and urine. Within the range of 200-1000 ng/ml (0.9-4.5 X 10(-6) M) fluorescence intensity increases linearly with concentration. Furthermore, when both emission and excitation spectra are combined there are no interferences due to organic substances normally present in those fluids. An extraction procedure of I from plasma and urine is also described, and the importance of I determinations in relation to the problem of this myotonia-inducing aromatic monocarboxylic acid is discussed.