Gait characteristics of patients with claudication.

OBJECTIVE: Intermittent claudication of the lower extremity vessels produces pain during walking. This study differentiates walking patterns of patients with claudication from walking patterns of healthy individuals. DESIGN: Nonrandomized case control study performed in a teaching university hospital outpatient setting. PATIENTS: The sample of convenience involved male patients with lower extremity claudication (n = 19) and 11 healthy men of similar ages. INTERVENTIONS: Subjects were asked to walk at self-selected speed for 20 meters on a level, indoor surface. OUTCOME MEASURES: Walking velocity and number of steps were averaged over each of five trials, and step length was calculated from these measures. RESULTS: Patients with claudication walked slower and had decreased step length and decreased cadence compared with controls (p < .001). No positive relationship was found between disease severity, peak walking time, and step length, cadence, or speed. CONCLUSION: All patients with claudication, regardless of disease severity, demonstrated abnormal gait parameters compared with controls. Further studies should evaluate whether the abnormal gait parameters significantly curtail walking ability.

Phosphonoformic acid blunts adaptive response of renal and intestinal Pi transport.

Parenteral administration of phosphonoformic acid (PFA) results in phosphaturia, but the effects of oral PFA on Pi handling are not known. To assess this effect, PFA was administered in drinking water for 5 days to rats stabilized on normal (NPD) or low (LPD) phosphorus diets. In renal brush-border membrane vesicles (BBMV), kinetic studies showed a higher apparent Vmax for Pi in rats on LPD compared with rats on NPD (1,840 +/- 274 vs. 1,111 +/- 192 pmol.mg-1.5 s-1, respectively, P < 0.05, n = 5). In LPD rats, PFA reduced the apparent Vmax for Pi to 1,047 +/- 191 pmol.mg-1.5 s-1 (P < 0.05, n = 5) with no change in the apparent Km. Similarly, there was a higher apparent Vmax for Pi in intestinal BBMV from rats on LPD compared with rats on NPD. In LPD rats, PFA reduced the apparent Vmax for Pi with no change in the apparent Km. Oral PFA had no effect on the kinetics of Pi transport in renal or intestinal BBMV from rats on NPD. Pi-protectable [14C]PFA binding was lower in renal BBMV from PFA-treated LPD rats, but membrane fluidity was not different. Orally administered PFA can blunt the adaptive response of the renal and intestinal BBM to an LPD. The downregulation of Na(+)-Pi cotransport is mediated through a reduction in the number of Na(+)-Pi cotransporters.