Intraarticular pressure and the relationship between synovial perfusion and metabolic demand

We examined the influence of intraarticular pressure on products of synovial energy metabolism in patients with knee effusions. A range of intraarticular pressures was generated by controlled flexion. Pressures greater than or equal to 45 mm Hg were associated with increased synovial fluid lactate concentrations and pCO2, and decreased pH. Our results suggest that pressures greater than or equal to 45 mm Hg, which we also observed during standing and walking, can cause synovial ischemia and hypoxia manifest in a perfusion/metabolic demand mismatch. Monitoring changes in SF concentrations of uric acid did not provide consistent evidence for accelerated purine degradation following periods of inadequate perfusion. Overall, our results suggest that synovial blood flow can be compromised by modest elevations in intraarticular pressure in the range encountered during daily activity in patients with knee effusions.     

Pharmacokinetics of cyclophosphamide in patients with systemic necrotizing angiitis

Summary— Cyclophosphamide pharmacokinetics were investigated following administration to patients with systemic necrotizing angiitis. Ten patients (eight women and two men) received cyclophosphamide as a 1-h-rate-constant intravenous infusion at doses ranging from 600 to 1200 mg. All patients received concomitant oral prednisone (1 mg/kg/d). Blood samples were collected at the end of drug infusion and 0.25, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 24 h later. Serum cyclophosphamide concentrations were assayed by high pressure liquid chromatography. The peak serum cyclophosphamide levels ranged from 15.7 to 29.4 mg/L. The mean cyclophosphamide elimination half-life was 6.2 ± 1.3 h (mean ± SD). The mean apparent volume of distribution and mean total plasma clearance were, respectively, 0.75 ± 0.22 L/kg (mean ± SD) and 83 ± 22 mL/min (mean ± SD). These results obtained in systemic vasculitic diseases were consistent with those observed in other studies with cancer patients receiving comparable doses of cyclophosphamide.     

Scanning electron microscpe study comparing the effecacy of endodontic irrigating systems

Summary. Thirty-five single rooted teeth were biomechanically instrumented with salaine, following' which they were subjected to different methods of irrigation. Four groups of teeth were irrigatied using and Endomate unit with NaOCl in combination with H₂O₂, or EDTA, or glutaraldehde or saline.
Two groups were irrigated with 5 per cent NaOCl in combination with ultrasound; one of them was further irrigated with 3 per cent H₂O₂ using the Endomate system.
The control group was irrigated with NaOCl and H₂O₂ using the conventional technique. The prepared root canals were examined for the presence of smear layer under SEM.
All groups irrigated with the ultrasonic technique and the group irrigated with the endomate system using EDTA solution showed significantly cleaner surfaces; the smear layer was also greatly reduced.     

Antegrade puncture of the femoral artery: morphologic study

To determine the optimal site for antegrade puncture of the femoral artery, the authors evaluated three cadaver specimens and computed tomographic (CT) scans of 50 patients. The relationships among the common femoral artery, the femoral artery bifurcation, the center of the femoral head, and the inguinal ligament were evaluated. CT showed that the center of the femoral head was always located caudal to the level of the inguinal ligament but cranial to the bifurcation of the common femoral artery. Therefore, the femoral head seems to provide a reliable landmark for entering the common femoral artery.