The amounts of DNA, RNA and protein synthesis were determined in Pisum sativum root meristem cells at various times after a 1 min exposure to 1 MHz ultrasound at a power density of 30 W/cm2. Immediate depressions in all three macromolecular syntheses occurred after sonication, followed by an apparent recovery several hours later. These events appear to correlate in time with the subsequent reduction and recovery in mitotic index in Pisum sativum root meristem cells exposed to 2 MHz ultrasound.

DNA↗

PubMedDate not supplied

Lack of ultrasound effect on in vitro human lymphocyte sister chromatid exchange.

The frequency of sister chromatid exchanges (SCEs) in human lymphocytes cultured in vitro was not affected by a 30 min exposure to a 2.25 MHz focused ultrasound beam (from a clinical diagnostic unit with a pulse repetition rate of 1000 Hz, a 1 mu sec burst duration, and a 2-200 W/cm2 maximum intensity). A 30 sec exposure to continuous wave 1 MHz 2 W/cm2 (SP) ultrasound from an experimental device lysed 10-15% of the lymphocytes; there was no increase in SCEs in the survivors relative to unexposed controls. Treatment of lymphocytes with 0.033 micrograms/ml mitomycin-C, a known SCE inducer, increased the frequency of SCEs about 4 times above control levels.

Cells, Cultured↗

PubMedDate not supplied

Lack of effect of high-intensity pulsed ultrasound on sister chromatid exchange and in vitro Chinese hamster ovary cell viability.

The frequency of sister chromatid exchanges (SCEs) in in vitro Chinese hamster ovary cells and their viability were not affected by 3-min exposures to 2-4 MHz, focused, pulsed ultrasound with a pulse repetition rate of 200 Hz, pulse duration of 10 mu sec and intensities (SPTP) of 500 W/cm2 and 2500 W/cm2. The viability results are consistent with those reported elsewhere; the SCE response does not verify a specific previously reported positive response.

Animals↗

PubMedDate not supplied

Failure of iosulamide to enhance hepatic tumors in rats.

Iosulamide, an experimental cholangiographic agent recently being evaluated for hepatic contrast enhancement in computed tomography, has been investigated in the rat for the differential enhancement between the liver and three histologically different experimental tumors (a well differentiated mammary adenocarcinoma, a poorly differentiated colon carcinoma, and a hepatoma). After intravenous injection of iosulamide in dosages of 140 and 280 mg iodine per kg, iodine concentrations were determined in blood, liver and tumors at 1, 5, 10, and 30 minutes, using x-ray energy spectrometry. Compared with the surrounding liver parenchyma, the iodine concentrations were generally higher in the breast carcinoma. With respect to the liver, iodine concentrations varied greatly in the colon carcinoma and hepatoma. The iodine washout from all three tumors was relatively slow. Since the distribution volume of cholangiographic contrast agents includes both vascular and interstitial space, the relatively high and prolonged iosulamide accumulation in tumors can be explained by a relatively large interstitial compartment, which is apparently characteristic of neoplastic lesions. This, together with the modest iodine concentrations found in the liver, suggests that iosulamide is of little use in computed tomography for the differential enhancement of liver and hepatic tumors.

Adenocarcinoma↗

PubMedDate not supplied

Factors modifying contrast media induced fibrillation.

Factors effecting contrast media induced ventricular fibrillation were studied in anesthetized dogs using contact time as the measured parameter. Injections of meglumine/sodium diatrizoate (370 mg I/ml) were made into the right coronary artery at 0.4 ml/s until fibrillation occurred. A contrast medium containing calcium chelators was found to produce fibrillation in a significantly shorter contact time than a similar medium without calcium chelators. Pre-treatment by the cardiac glycoside, ouabain, increased the contact time for fibrillation as did the production of a sub-acute infarction in the left coronary artery and a previous fibrillation and resuscitation. The data suggest that calcium binding additives increase the risk of fibrillation while pre-treatment with cardiac glycosides, the presence of stable infarcts in the non-injected areas, or a previous fibrillation and resuscitation do not increase risk.

Animals↗