The objective of the current study was to determine the best index of residual glomerular filtration rate (GFR) by comparing simultaneously measured clearances of inulin, 125I-iothalamate, endogenous creatinine, urea and 169ytterbium diethylenetriaminepentaacetic acid (169YB-DTPA) in patients receiving repetitive hemodialysis. In patients with GFR less than 5 ml/min but greater than 1 ml/min, 125I-iothalamate clearance showed the best correlation with inulin clearance. However, creatinine clearance correlated better with inulin clearance than urea clearance and as well as urea + creatinine/2. In the patients with measured GFR less than 1 ml/min, the correlation of 125I-iothalamate, creatinine, urea and urea + creatinine/two clearances with inulin clearance was satisfactory. Similarly, satisfactory correlations were obtained when the relationships were examined across the entire range of measured clearances less than 5 ml/min. A simple, practical method is descriged for the accurate serial measurement of residual GFR in patients receiving repetitive dialysis.
Physical and lifestyle data were collected from 62 postmenopausal women who had declined hormone replacement therapy. Potential predictor variables were examined for their associations with bone mineral density (BMD) of the lumbar spine and femoral neck as assessed by dual x-ray absorptiometry. Body weight demonstrated the strongest association with lumbar BMD; lean body mass demonstrated the strongest association with femoral BMD. Together with the natural logarithm of the number of years since menopause (ln YSM) these anthropometric variables explained 36 and 34% of the variability of femoral and lumbar BMD, respectively. Serum estradiol levels demonstrated a weak positive association with BMD, which lost statistical significance after adjustment for body mass. Similarly, cardiovascular fitness was positively associated with femoral BMD prior to but not following adjustment for body mass. Controlling for years since menopause and body mass, the product of dietary calcium and calcium absorption demonstrated a weak positive correlation with femoral BMD (partial r = 0.30). The intake of tea was positively and significantly associated with both bone density measurements. In multiple regression analysis, femoral BMD was best explained by the lean body mass, ln YSM, and the daily intake of tea (r2 = 0.50). Similarly, lumbar BMD was best explained by body weight, ln YSM, and intake of tea (r2 = 0.44). Body mass is a major predictor of postmenopausal bone density at the hip and spine. A positive association between dietary calcium and BMD was detected only by taking into account the intestinal absorptive efficiency.
Physical and lifestyle data were collected from 62 postmenopausal women who had declined hormone replacement therapy. Potential predictor variables were examined for their associations with bone mineral density (BMD) of the lumbar spine and femoral neck as assessed by dual x-ray absorptiometry. Body weight demonstrated the strongest association with lumbar BMD; lean body mass demonstrated the strongest association with femoral BMD. Together with the natural logarithm of the number of years since menopause (ln YSM) these anthropometric variables explained 36 and 34% of the variability of femoral and lumbar BMD, respectively. Serum estradiol levels demonstrated a weak positive association with BMD, which lost statistical significance after adjustment for body mass. Similarly, cardiovascular fitness was positively associated with femoral BMD prior to but not following adjustment for body mass. Controlling for years since menopause and body mass, the product of dietary calcium and calcium absorption demonstrated a weak positive correlation with femoral BMD (partial r = 0.30). The intake of tea was positively and significantly associated with both bone density measurements. In multiple regression analysis, femoral BMD was best explained by the lean body mass, ln YSM, and the daily intake of tea (r2 = 0.50). Similarly, lumbar BMD was best explained by body weight, ln YSM, and intake of tea (r2 = 0.44). Body mass is a major predictor of postmenopausal bone density at the hip and spine. A positive association between dietary calcium and BMD was detected only by taking into account the intestinal absorptive efficiency.
Recent reports suggest that the apparent magnetosensitivity of the rat pineal gland is a result of induced electric currents (eddy currents) in the animals caused by the transients of activation and deactivation of artificially applied magnetic fields (MF). To test this, young adult male rats were exposed at night when pineal melatonin production is high to situations that caused either the induction of eddy currents or eddy currents plus an intermittently inverted MF. Only those animals exposed to both the inverted MF and induced eddy currents demonstrated alterations in nocturnal pineal indoleamine metabolism. These results demonstrate that the response of the rat pineal gland to an inversion of the MF may be a consequence of at least two interacting factors, i.e., the inverted MF and the induced electric currents.
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