Global and regional myocardial uptake was determined with technetium-99m tetrofosmin and a 4 hour exercise (370 MBq i.v.) and rest (740 MBq i.v.) protocol, in 24 patients with non-insulin dependent diabetes mellitus and in 22 control subjects. The purpose of this study was to evaluate impaired coronary microvascular function in diabetics by measurement of % uptake increase in myocardial counts. The parameter of % uptake increase (deltaMTU) was calculated as the ratio of exercise counts to rest myocardial counts with correction of myocardial uptake for dose administered and physical decay between the exercise study and the rest study. Global deltaMTU was significantly lower in the diabetics than in control subjects (14.4 +/- 5.4% vs. 21.7 +/- 8.5%, p < 0.01). Regional deltaMTU in each of 4 left ventricular regions (anterior, septal, inferior, posterolateral) was significantly lower in the diabetic group than in the control group (p < 0.01) respectively, but there were no significant differences between deltaMTU in the 4 left ventricular regions in the same group. deltaMTU was useful as a non-invasive means of evaluating impaired coronary microvascular function in diabetics.

The heat of reactions in supercritical water is difficult to measure. Our group fabricated a new reactor to enable the measurement of this heat with extremely high accuracy. The system consisted of a single, insulated tube reactor. The reaction heat was determined by the temperature change of the flow caused by the heat. We found, however, that the heat loss of the reactor compromised the measurements accuracy. Though small, this factor was impossible to completely remove, especially when the reaction was fast or the flow was slow. To compensate, we measured the heat loss and used the measured value to correct our calculation of the reaction heat. The direct measurements of the reaction heat agreed well with the calculated values, with relative error of only around 5% up to reaction heats as large as 100 kJ/kg-water.