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The ratio of peak hyperemic/basal mean coronary flow velocity, an index of coronary vasodilator reserve, immediately after coronary angioplasty normalizes in less than 50% of patients. To evaluate other indexes of coronary vasodilator capacity, both intracoronary arterial velocity and cardiac venous efflux were measured at rest and during vasodilator-induced coronary hyperemia (intracoronary nitroglycerin and papaverine) before and after angioplasty in 27 patients; 17 patients had measurements of intracoronary velocity alone and 10 had thermodilution measurements of great cardiac vein flow. Coronary flow velocity responses were also measured in 6 angiographically normal segments in patients undergoing angioplasty and in 10 normal left coronary artery segments in patients with normal coronary arteries or isolated right coronary artery disease. Despite significant angiographic (72 +/- 12 to 23 +/- 11% diameter narrowing) and hemodynamic (49 +/- 12 to 19 +/- 12 mm Hg aortocoronary gradient) improvement, coronary vasodilator reserve ratios for both arterial velocity and venous flow after angioplasty were only minimally affected. Angioplasty did not significantly increase rest coronary vein flow or artery flow velocities, but did result in significantly higher papaverine responses after angioplasty. Mean and phasic coronary velocity, diastolic coronary flow velocity integral and measured great cardiac vein flow ratios were significantly lower when compared with those in 16 angiographically normal coronary artery segments. These data indicate that maximal hyperemic coronary flow velocity is increased after angioplasty, but the reserve ratios, calculated by any of several flow velocity indexes, remain minimally improved. Angiographic correlations (percent coronary diameter, absolute diameter or cross-sectional area) with variables of coronary blood flow or velocity suggest that no single variable is useful in assessing angioplasty results. However, postangioplasty arterial mean velocity and diastolic flow velocity integral are nearly normalized in most patients, whereas relative changes remain attenuated. These findings are important in studies assessing coronary vasomotor responses in patients with atherosclerotic coronary disease, especially after angioplasty.

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Reactive dyes constitute a significant portion of colorants used in industries ranging from the textile industry to the paper industry. In most cases, the effluent streams from textile plants are highly colored, and treatment methods for dye decolorization such as chemical oxidation need to be explored. The oxidation processes investigated in this study are those of ozonation, ultrasound, and ultrasound-enhanced ozonation. The oxidation of an anthraquinone dye was studied under conditions of varying ultrasonic power, dye concentration, ozone concentration, pH, and temperature. Laboratory experiments were performed using a semibatch reactor by ozonating dye samples with and without ultrasound. Under conditions of constant ultrasonic radiation and continuous gas application, decolorization rates have been enhanced by ultrasound. The apparent firstorder rate constants increased between 35 and 204% for the ultrasonic power inputs between 40 W/L and 120 W/L compared with ozonation alone. The effects of ultrasonic power input on the gas-liquid mass-transfer coefficient were also investigated and the results indicate that an increase in ultrasonic power input increases the mass-transfer coefficient. The masstransfer coefficient increased between 89 and 93% for ozone inlet concentrations between 5.4 and 9.4 mg/L at an ultrasonic power of 120 W/L compared with ozonation alone. The reactions of the dye with ultrasound-enhanced ozone occurred through the hydroxyl radical pathway. Water Environ. Res., 75, 171 (2003).

The human placenta has been implicated in the poor growth and development of the embryo/fetus due to alterations in blood flow and reductions in the transfer of nutrients such as amino acids and carbohydrates. Deficiencies of such nutrients have been the principal of many research investigations. The role of micronutrients, however, may also be major factors in appropriate growth and development, and there may be a general reduction in the availability of such nutrients, for example, the role of folate supplementation during early pregnancy and the reduction in the incidence of neural tube defects. Vitamins are not all transported via a common mechanism. Therefore, the modulation of human placental transport can be different for different vitamins, for example, A and B12. It is apparent that the human placenta can oxidatively metabolize retinoids (isotretinoin and tretinoin) to more toxic or less toxic metabolites. These metabolites can then be transferred to the fetal circulation. Such metabolism/transfer is in contrast to how vitamin B12 is bound to transcobalamin proteins, which are produced by the placenta and directionally released into the maternal and fetal circulations.