Tibial displacement with stifle joint flexion and cranial cruciate ligament transection in the dog. An ex vivo study using a robotic simulator.

OBJECTIVE: The aim of this study was to investigate the biomechanical effects of cranial cruciate ligament (CrCL) transection on stifle stability at three different stifle joint flexion angles using a robotic system. METHODS: This was an ex vivo biomechanical study. Stifles (n = 6) were collected from the cadavers of Beagles weighing 10.5-12.0 kg. Six stifle joints were dissected, potted, and secured to the manipulator arms of a robotic simulator. With the stifle joint angle maintained at either hyperextension (151°), 135° or 90°, stability was assessed by application of a 50 N load in either the cranial-caudal (CrCd test) or proximal-distal (PD test) directions. The stifle was given a cranial-caudal load of 50 N (CrCd test). A proximal-distal compression load of 50 N was then administered by the manipulator (proximal-distal test: PD test). The change in three-dimensional kinematics of the intact and the CrCL-transected stifles was compared between hyperextension, and 135° and 90° flexion for the CrCd and PD load conditions. A value of p <0.05 was considered statistically significant. RESULTS: The cranial tibial displacements in the PD tests of the CrCL-transected stifles at 135° (8.4 ± 1.2 mm) and at 90° (8.1 ± 1.9 mm) were significantly greater than the displacement at 151.5° (5.1 ± 1.6 mm) (p = 0.004 and p = 0.012 respectively). CLINICAL SIGNIFICANCE: The canine stifle exhibited the most instability when the stifle flexion angle was 135°.

Mechanical functions of the three bundles consisting of the human anterior cruciate ligament.

PURPOSE: The reconstruction technique to individually reconstruct multi-bundles of the anterior cruciate ligament (ACL) has been improved in the last decade. For further improvement of the technique, the present study was conducted to determine the force sharing among the three bundles (the medial and lateral bundles (AMM and AML) of the anteromedial (AM) bundle and the posterlateral (PL) bundle) of the human ACL in response to hyperextension, passive flexion-extension and anterior force to the knee. METHODS: Using a 6-DOF robotic system, the human cadaveric knee specimens were subjected to hyperextension, passive flexion-extension and anterior-posterior tests, while recording the 6-DOF motion and force/moment of the knees. The intact knee motions recorded during the tests were reproduced after sequential bundle transection to determine the bundle forces. RESULTS: The bundle forces were around 10 N at 5 N-m of hyperextension and remained less than 5 N during passive flexion-extension. In response to 100 N of anterior force, the AMM and PL bundle forces were slightly higher than the AML bundle force at full extension. The AMM bundle force remained at a high level up to 90° of flexion, with significant differences versus the AML bundle force at 15°, 30° and 60° of flexion and the PL bundle force at 90° of flexion. CONCLUSION: The AMM bundle is the primary stabilizer to tibial anterior drawer through wide range of motion, while the AML bundle is the secondary stabilizer in deep flexion angles. The PL bundle is the crucial stabilizer to hyperextension as well as tibial anterior drawer at full extension.

[A case of gastric cancer with multiple bone metastasis treated by nocturnal 5-fluorouracil infusion combined with pamidronate].

Nocturnal infusion of 5-fluorouracil (5-FU) combined with pamidronate was performed in a 62-year-old male gastric cancer patient with multiple bone metastasis. The patient was administered 500 mg of 5-FU five days a week continuously for 10 hours per day from 21 o'clock to 7 o'clock for 5 months. In addition to 5-FU, 45 mg of pamidronate was administered intravenously every two weeks. Remarkable sclerotic changes were shown during the treatment in the bone metastatic foci, and the range of motion was enlarged. Serum levels of CEA and CA19-9 were decreased to the normal levels. There were no serious side effects such as myelosuppression, diarrhea or palmo-plantar dermatitis. This combination therapy of nocturnal infusion of 5-FU with pamidronate was considered effective for gastric cancer in patients with multiple bone metastasis without serious side effects.

[Determination of delta-aminolevulinic acid dehydratase (ALAD) by enzyme immunoassay and its application to evaluation of lead exposure].

Enzyme Immunoassay (EIA) technique using a glass bead was established in order to quantify the total amount of delta-aminolevulinic acid dehydratase (ALAD, EC 4, 2, 1, 24) including an inactivated enzyme and to determine the level of ALAD in erythrocytes of workers with moderate lead exposure. EIA was carried out by competitive antibody binding method in which the antigen (ALAD) was linked to a glass bead (O.D. 7 mm). A standard curve was fitted to the function y = A X B/(x-B) + C, where y is the enzymatic reaction product, x is the concentration of ALAD, and A, B and C are parameters. The coefficients of variation in the intra- and inter-assay were 3.7% and 6.5%, respectively. EIA-based amount of ALAD was 136.7 +/- 23 mg/l erythrocyte (mean +/- S.D.) in 66 workers. This ALAD amount was not found to be correlated with the lead level in the blood but correlated with the duration of lead-exposure. An especially good correlation (r = 0.453) was obtained with the inactivated portion of ALAD (EIA-based amount minus activity-based amount). On the other hand, the ratio of restored activity following heat treatment and addition of Zn and dithiothreitol to non-restored activity was well correlated with the lead level (r = 0.874), but not correlated with the duration of lead-exposure (r = 0.218). The inactivated portion of ALAD based on EIA accordingly may be considered a good indicator of the duration of lead exposure, and the activity-based amount of ALAD may be considered a suitable indicator of the extent of the present lead exposure.

Bile acid metabolism in partially hepatectomized rats.

The bile flow and the bile acid secretion, calculated on liver weight basis, increased 12 H and 24 H after 60-70% hepatectomy and returned to the initial levels thereafter. The biliary phospholipid secretion much more increased than bile acids, but the cholesterol secretion decreased. Bile acid composition changed with an increase of the cholic acid group and a decrease of the chenodeoxycholic acid group in both bile and feces. These changes almost disappeared on Day 14. The pool size of bile acid decreased maximally on Day 4 to about 40% of the initial, but the distribution of bile acids in the enterohepatic circulation was not changed. The fecal cholesterol and coprostanol markedly decreased on Day 2 but gradually returned to the initial levels according to the recovery of diet intake. The fecal bile acids decreased on Day 2, increased on Day 4, and returned to the normal range after Day 7. In conclusion, the regenerating liver secretes more bile, bile acids and phospholipids, and less cholesterol than the normal liver. Cholic acid predominates in the bile acids. These changes restored to the initial levels by about one week after the operation.