Ecological risk assessment of urban creek sediments contaminated by untreated domestic wastewater: potential contribution of antimicrobials and a musk fragrance.

Despite the fact that some hydrophobic pharmaceuticals and personal care products (PPCPs) have been found to accumulate in river sediments, little is known about the contribution of these compounds to the toxicity of the whole sediment. We sampled river sediments from two urban creeks with an unsewered drainage area to investigate the toxicity for a benthic organism, Chironomus yoshimatsui. The concentrations of selected hydrophobic PPCPs, triclosan (TCS), triclocarban (TCC) and galaxolide (HHCB) were analysed using gas chromatographic mass spectroscopy or liquid chromatographic mass spectroscopy and were found to lie within the range 50 to 200 ng g(-1). The toxicity of the three individual contaminants for the chironomid was also determined. The toxicity of TCC was found to be the strongest, with an NOEC value of 2.5 microg g(-1). Combining the toxicity and measured environmental concentration, the ecological risk was assessed and the contribution of these contaminants to the whole sediment toxicity estimated, assuming additivity. The hazard quotient of all three compounds, determined without assessment factor, ranged between 0.01 and 0.1. The combined contribution of the three compounds to total sediment toxicity was as high as 8.2%, but other unknown factors may also make an important contribution.

Amicarbalide: a therapeutic agent for anaplasmosis.

When administered subcutaneously in 2 equal daily doses at a total dosage rate of 20 mg/kg, amicarbalide was found to be an effective agent for controlling acute infections of Anaplasma marginale and A. centrale in intact and splenectomized cattle. Attempts to sterilize patent and latent Anaplasma infections, however, were unsuccessful. At total dosage rates of 40 mg/kg and higher, amicarbalide exhibited potent hepato- and nephrotoxic tendencies.

Clinical, histologic, and histochemical study of imidocarb diproprionate toxicosis in goats.

The toxic effects of imidocarb diproprionate (3,3'-bis [2 imidazolin-2yl]-carbanilde diproprionate) were evaluated in adult goats given (intramuscular injection) a lethal dose (6.75 mg/kg). The immediate clinical signs of toxicosis were transient excessive salivation and diarrhea. Anorexia, dyspnea, recumbency, and death occurred between postinjection days (PID) 4 and 8, during which time 7 goats died and 4 moribund goats were euthanatized. There were marked increases in mean serum urea nitrogen concentration and significant increases in serum glutamic oxalacetic transminase activity and in the mean number of circulating neutrophils after PID 4. Renal hyperemia and enlargement were evident by PID1. Serosanguineous fluid in the trachea and major bronchi, pulmonary congestion and edema, hydrothorax, hydroperitoneum, and less frequently hydropericardium were observed on and after day 4. Microscopic renal tubular lesions rapidly progressed from pyknotic epithelial nuclei observed at 6 and 12 hours to acute tubular necrosis of epithelium of the proximal convoluted tubules on days 1 and 2. Pulmonary congestion and edema; hemorrhage into alveoli, bronchioles, and bronchi; and intracytoplasmic lipid vacuoles within the hepatocytes in the periacinar zones of the hepatic lobules were observed on or after day 4. Succinic dehydrogenase and adenosine triphosphatase activities decreased progressively in the epithelial cells of the proximal convoluted tubules. The decreases in cellular enzymatic activity occurred shortly after the appearance of microscopic lesions in the tubular epithelium.