Sonochemicals increase the mutation frequency of V79 cells in vitro

Contrast-enhanced Ultrasound in Obstetrics and Gynecology

Ultrasonography is a well-established imaging modality for evaluation of gynecologic tumors. In recent years, more sophisticated technologies like the use of intravascular contrast agents led to an improvement in the ability of the practitioner to differentiate benign from malignant masses. When we consider the safety of contrast-enhanced ultrasonography in obstetrics and gynecology, we must discuss about the effect of ultrasound contrast media on embryo and fetus. The use of ultrasound contrast media in pregnant women always concerns in the obstetricians because of the principle of not exposing a fetus to any drug. Therefore, the literature was reviewed for information about those safety and efficacy because of the uncertainty about the use of contrast media during pregnancy. Based on the limited information available, mutagenic and teratogenic effects have not been described after administration of ultrasound contrast media. No effect on the fetus has been seen after contrast media. The small potential risk associated with the nonthermal bioeffects via acoustic cavitation may be considered to prohibit the use in first trimester pregnant women. In previous studies including human trials, no evidence of adverse effect was reported. Contrast-enhanced ultrasonography could prove a useful adjunct in multiple gestations and in evaluation of uteroplacental circulation. It appears to be very promising potential in obstetrics.

Ultrasound-assisted lipoplasty

BACKGROUND

Ultrasound-assisted lipoplasty (UAL) has been associated with particular types of complications and uncertain long-term effects arising from interactions between ultrasonic energy and living tissue. The present review seeks to address these issues.

METHODS

Search strategy Three search strategies were devised to retrieve literature from Medline, Current Contents, Embase and Cochrane Library databases up until April 2000. Study selection Inclusion of papers was largely determined using a predetermined protocol. English language papers were selected. Acceptable study designs included randomized controlled trials, controlled clinical trials, case series or case reports. Data collection and analysis Thirty-six papers met the inclusion criteria. They were tabulated and critically appraised in terms of methodology and design, outcomes, and the possible influence of bias, confounding and chance. Other papers were also included to provide background material.

RESULTS

There was little high-level evidence available comparing UAL and suction-assisted lipoplasty (SAL), with no conclusive evidence that UAL has a safety benefit, although low-quality evidence suggests that UAL is associated with reduced surgeon fatigue as well as increased operating times, slower aspiration rates and an increased learning curve. There is inadequate evidence to determine whether the theoretical potential for DNA damage from ultrasound is realized in the clinical setting.

CONCLUSIONS

The evidence base for UAL is inadequate to determine the procedure's safety and efficacy. The potential for DNA damage must be investigated with appropriate in vivo animal models. Recommendations for the safe use of UAL are discussed.

Effects of cysteamine and cystamine on the sonochemical accumulation of hydrogen peroxide--implications for their mechanisms of action in ultrasound-exposed cells

Based on the observed cytoprotective effect of the intracellularly permeable radical scavenger cysteamine (+NH3CH2CH2SH) in cells exposed to ultrasound and the lack of protection by its oxidized cell-nonpermeable form, cystamine (+NH3CH2CH2S-SCH2CH2NH3+), it was suggested that inertial cavitation (the growth of small gas bubbles present in the liquid exposed to ultrasound and their subsequent violent collapse) and associated free radical production may occur intracellularly (Radiat. Res. 89:369; 1982). Here we demonstrate that high concentrations (> 10 mM) of the thiol cysteamine effectively lower H2O2 yields following ultrasound exposure in argon- and air-saturated phosphate buffered saline (PBS), while cystamine is less effective under argon and practically without effect in air-saturated PBS. Direct removal of H2O2 by cysteamine is the dominant mechanism while scavenging of the H2O2 precursors .OH and superoxide plays a lesser role. Since H2O2 is a known cytotoxic species capable of penetrating cells if produced extracellularly, these results offer an alternative hypothesis for the protective effect of cysteamine and the lack of protection by cystamine, based on their differential ability to lower ultrasound-dependent H2O2 yields, without the necessity of invoking intracellular cavitation.