Effect of exercise on 99mTc-DTPA clearance from knees with effusions.

OBJECTIVE: To devise and use a method for assessing the effect of dynamic exercise on synovial blood flow in knees with effusions. METHODS: The clearance rate of intraarticular 99mTc-DTPA (diethylene triamine pentaacetic acid) was continuously monitored by a gamma camera during periods of rest or flexion. The rate of 99mTc-DTPA disappearance during a fixed period of exercise which was interposed between 2 rest periods was estimated by extrapolation between the clearance curves for the 2 rest periods. RESULTS: Cycling and walking increased the clearance rate, straight leg raising had no effect, and flexion decreased the clearance rate. CONCLUSION: Our results suggest that some dynamic exercises can increase the rate of synovial blood flow in joints with effusions. This outcome may be beneficial in inflamed joints which are chronically hypoxic due to elevated intraarticular pressure and consequent chronic synovial ischemia.

A comparison of four methods of estimating the body composition of male endurance athletes.

Comparisons were effected of the following four methods of estimating the percent body fat (%BF) of 12 highly trained male endurance athletes (mean +/- SD = 2.20 +/- 4.9 years, 176.8 +/- 5.9 cm 64.2 +/- 6.4 kg): underwater weighing (UWW), total body water (TBW), total body potassium (TBK) and dual-energy X-ray absorptiometry (DEXA). The DEXA mean of 6.8% BF was significantly less (P < 0.05) than those estimated via UWW: 9.7% BF; TBW: 10.6% BF (fat-free mass of FFM = 72.0% H2O); and TBK: 9.7% BF (FFM = 66.6 mmol K.kg-1). Nevertheless, the DEXA % BF correlated 0.746 and 0.737 (both P < 0.01) with those from UWW and TBW, respectively; these were the only correlation coefficients to attain statistical significance (P < or = 0.05). Despite the similar means for UWW, TBW and TBK, 12 of the 36 individual differences between these three methods ranged from 3.2 to 10.4% BF. A critical assumption of UWW, which is regarded by many as the criterion method for the estimation of % BF, is that the FFM has a density of 1.100 g.cm-3. Use of in vivo-measured TBW and bone mineral (via DEXA) for the computation of FFM densities for our subjects, while assuming that the two other components of the FFM (protein and non-bone mineral) remained constant, resulted in scores ranging from 1.09541 to 1.10246 g.cm-3 (mean +/- SD = 1.09881 +/- 0.00254 g.cm-3). FFM and % BF differences between use of a constant FFM density of 1.100 g.cm-3 and the individual values ranged from -1.02 to 0.57 kg (mean +/- SD = -0.28 +/- 0.60 kg) and from -0.9 to 1.7% BF (mean +/- SD = 0.5 +/- 0.9% BF), respectively. It may be concluded that with young male athletes: (1) use of constants based on normal male cadavers yielded similar group means for % BF determined by UWW, TBW and TBK but the DEXA % BF correlated significantly with those from UWW and TBW; and (2) in vivo measurements of individual differences in TBW and bone mineral support the use of conventional UWW for the estimation of % BF.

A comparison of the effect of lisinopril and hydrochlorothiazide on electrolyte balance in essential hypertension.

The effects of lisinopril 10-20 mg or hydrochlorothiazide 25-50 mg (each given once daily) on blood pressure, serum sodium, potassium and magnesium concentrations, total body potassium and urinary cation excretion were compared in a group of hypertensive patients using a double blind randomised crossover design. Each active treatment phase lasted six weeks and a total of sixteen patients completed the study. Both lisinopril and hydrochlorothiazide produced clinically significant decreases in blood pressure. However, lisinopril treatment produced a mean reduction of 14 mmHg in sitting diastolic pressure compared with a 7 mmHg reduction for hydrochlorothiazide treatment. This difference was statistically significant. The decrease in the concentration of serum potassium during hydrochlorothiazide treatment was greater than that during lisinopril treatment (0.53 vs 0.01 mmol.1). The absolute value of serum potassium was significantly lower on hydrochlorothiazide than on lisinopril therapy. Neither treatment had an effect on serum magnesium concentrations, nor was there any significant effect of either treatment on urine volume or urinary excretion of sodium, potassium or magnesium. There was a trend towards increased total body potassium concentration on lisinopril compared with a decrease in total body potassium on hydrochlorothiazide. However, this difference was just outside the range of statistical significance. Both treatments were equally well tolerated. The results indicate slight superiority of lisinopril over hydrochlorothiazide with regard to control of diastolic blood pressure with a better effect on overall electrolyte balance.

Can serial scintigraphic studies detect delayed fracture union in man?

The uptake of the bone-seeking tracer technetium-99m-methylenediphosphonate increases following bone fracture as bone healing occurs. To investigate the pattern of change in normal healing and compare it with delayed union and nonunion, an analysis of automated computer profiles was carried out on serial scan data for 22 patients. The type of fracture (simple, comminuted, etc.) influenced the appearance of the activity profile; however, no significant differences in the patterns of change were noted between normal healing and delayed or non-union.