Search

To confirm whether the microbubble activated by sonication causes liver damage, the authors performed two experiments. Experiment 1 followed Shigeta's experiment. As an ultrasound contrast agent (UCA), Levovist was used and sonicated by Acuson Sequoia™ 512 by Siemens. Wister rats of 300 g were divided into four groups: (A) administration of ultrasonic contrast agent (UCA) and ultrasonic exposure, (B) administration of UCA, (C) ultrasonic exposure, and (D) control. Experiment 1 did not show the evidence of hepatic damage such as Shigeta et al. reported. Hence, we conducted Experiment 2 with a much higher acoustic output. But no clear damage was observed in both optical and electron microscopic specimens.

The formation oxytetracycline (OTC) degradation products in chicken and pork under two different methods of cooking were studied. Samples of chicken and pig muscles previously dosed with OTC residues were subjected to boiling or microwave treatment, and the residues were extracted in a mixture of citrate buffer-MeOH (75:25 v/v), and then analyzed by high performance liquid chromatography with photodiode array detection using a XBridgeTM C18 reverse-phase chromatographic column. Thermal treatment resulted in the degradation of OTC and the concentrations of the degradation products α-apo-oxytetracycline (α-apo-OTC) and β-apo-oxytetracycline (β-apo-OTC) in muscle samples amounted to 0.7 to 1.2 % of the initial OTC content. The toxic effects of the degradation products of oxytetracycline, α-apo-OTC and β-apo-OTC were studied in rats. Male rats received oral doses of 10 mg/kg body weight/day of either α-apo-OTC, β-apo-OTC, 90 days. The results of this study suggest that the toxic effects of β-apo-OTC treatment could damage liver and kidney tissues of rats, as well as lead to the degeneration and necrosis in the hepatocytes.