Effects of tetrachloroethylene on the viability and development of embryos of the Japanese medaka, Oryzias latipes.

We evaluated the acute toxicity of Tetrachloroethylene (C(2)Cl(4)), and investigated its sub-chronic effects on the embryonic development of Japanese medaka (Oryzias latipes). One-day-old eggs/embryos of this fish species were exposed, under static renewal conditions, to serial concentrations (0, 20, 40, 60, and 80 mg/L) of C(2)Cl(4) for 96 h (acute) and 10 days (sub-chronic) time periods. The toxic endpoints evaluated included: egg/embryo viability, hatchability, and morphological/developmental abnormalities. The acute toxicity test resulted in a 96 h-LC(50) of 27.0 (19.5-32.9) mg/L for egg viability. Exposure of eggs to sub-chronic concentrations (0, 1.5, 3, 6, 12, and 25 mg/L) of C(2)Cl(4) significantly reduced hatchability and larval survival, in a concentration dependent manner. At the highest tested concentration (25 mg/L) of the sub-lethal exposure, larval survival was greatly reduced to within three days post-hatch. The lowest tested concentration (1.5 mg/L) produced a significant number of developmental effects to the Japanese medaka, including abnormal development of the circulatory system, yolk-sac edema, pericardial edema, scoliosis, hemorrhaging, blood pooling, and defects in heart morphology. The severity of these abnormalities was concentration-dependent. It can be concluded from these results that tetrachloroethylene is teratogenic to the Japanese medaka.

Splenic venous flow exceeding portal venous flow at Doppler sonography: relationship to portosystemic varices.

OBJECTIVE: The purpose of this study was to determine if the Doppler sonographic finding of hepatopetal flow in the splenic vein that exceeds hepatopetal flow in the portal vein is associated with portosystemic varices. MATERIALS AND METHODS: Sixty-four patients with chronic liver disease were studied retrospectively. In 32 patients, splenic venous flow exceeded portal venous flow (S > P group); in 32 patients, portal venous flow exceeded splenic venous flow (P > S group). All patients were evaluated with Doppler sonography and CT of the upper part of the abdomen. Upper endoscopy was performed within 3 months of sonography in 44 of the 64 patients. RESULTS: In the S > P group, mean splenic volume was significantly larger (p = .02) than in the other group. The prevalence of varices as determined by CT in the esophageal, coronary, and peripancreatic regions was also higher in this group (p < or = .01). When esophageal varices were present, they were judged on the basis of their CT appearance to be massive in 50% of the S > P group and in 0% of the P > S group. Upper endoscopy revealed esophageal varices in 92% of the S > P group and in 55% of the P > S group (p < .005). Bleeding esophageal varices were noted in 75% of the S > P group and in 30% of the P > S group (p < .01). CONCLUSION: Patients with chronic liver disease and the Doppler sonographic finding of splenic venous flow that exceeds portal venous flow have an increased prevalence of portosystemic varices, which tend to be larger and more likely to bleed.

Magnetic resonance imaging after arterial portography with manganese dipyridoxal diphosphate.

RATIONALE AND OBJECTIVES: The authors assess performing hepatic magnetic resonance imaging (MRI) after arterial portography with manganese dipyridoxal diphosphate (MnD-PDP), a hepatobiliary contrast agent, as an invasive but potentially highly sensitive means of focal lesion detection. METHODS: Eight pigs underwent superior mesenteric artery catheterization and injection of 10 mumol/kg MnDPDP. Magnetic resonance imaging at 1.5 T (SE-140/10) was performed before, then at 15 and 30 minutes after injection. Seven or more days later, the same MRI protocol was performed after intravenous injection of 10 mumol/kg MnDPDP. RESULTS: Fifteen minutes after intra-arterial injection, enhancement of the liver predominated (86 +/- 13%), followed by the renal cortex (44 +/- 14%), pancreas (26 +/- 9%), and spleen (14 +/- 9%). At 30 minutes, enhancement of renal cortex significantly increased (50 +/- 14%). There was no significant difference in enhancement of the liver, spleen, pancreas, or renal cortex when we compared intra-arterial and intravenous administration. CONCLUSION: After the injection of 10 mumol/kg MnDPDP into the superior mesenteric artery of pigs there is no significant difference in visceral organ enhancement compared to intravenous administration. The data suggests that the hepatocyte binding sites may be overwhelmed by this dose and/or injection rate of MnDPDP.