We have previously shown that the myocardial Gd-DTPA concentration ([Gd-DTPA]t(t)) after a bolus injection of Gd-DTPA can be predicted by the Modified Kety Equation (MKE). If [Gd-DTPA]t(t) can be determined by MRI and the data fit to the MKE, then the distribution volume (lambda) of Gd-DTPA and the myocardial flow (F) times the extraction efficiency (E), i.e., the FE product, can be determined. Therefore F can only be quantified if E is known. We measured the global E in vivo in normal canine myocardium, and measured E and lambda, in vitro, locally in normal, acute ischemic (n = 5; coronary artery occlusion < 4 h), infarcted (n = 4; coronary artery occlusion, 6 days) and reperfused (n = 4; coronary artery occlusion 2 h, and reperfusion 2 h and 6 days) myocardium. Results indicate that E differs with F and with individuals and consequently, F cannot be quantified using the MKE unless the local E is also determined in vivo.
This study examined the validity, reliability, and discriminatory capacity of the gallon-jug shelf-transfer (GJST) test. Six hundred fifty-three independent-living older adults (463 women age 72.9 +/- 7.0 years, 190 men age 74.3 +/- 6.7 years) participated. Participants moved five 1-gallon jugs (approximately 3.9 kg) from a knee-high to a shoulder-high shelf as quickly as possible. The GJST showed an exponential performance decline with age, and there were significant correlations between the GJST and common functional tests (p<.001). High within-day and between-days reliability was detected. The test also detected differences resulting from training status (p<.01) and training protocols (p<.05). The GJST is a valid, reliable, inexpensive, safe, and easily administered clinical test for identifying physically vulnerable elders who could benefit from interventions such as exercise to improve their physical capacities and maintain independence.
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