GM1 enhances the association of neuron-specific MAP2 with actin in MAP2-transfected 3T3 cells.

The ganglioside GM1 is a glycosphingolipid which enhances process formation of several neuronal lines and potentiates some growth factor-mediated responses. Previously we have shown that 24 h exposure of Neuro 2a cells to GM1 mobilized the neuron-specific microtubule-associated protein, MAP2, away from microtubule-rich areas to areas of neurite sprouting where MAP2 was more closely associated with the subcortical actin network. To examine the role of GM1 in fostering the shift of the association of MAP2 from tubulin to actin, NIH 3T3 cells were co-transfected with pHook-1, which expresses a surface antigen, and a construct expressing MAP2. Transfected cells were selected with magnetic beads coated with a hapten that binds to the expressed surface antigen and treated with 150 microg/ml GM1 for 18-24 h. Actin and MAP2 or tubulin and MAP2 were immunolocalized and examined with confocal microscopy. MAP2 was found throughout the cytoplasm as well as associated with actin filaments. As observed previously with Neuro 2a, GM1 treatment of transfected fibroblasts redistributed the MAP2 away from direct association with microtubules to peripheral areas where the association of MAP2 with actin was enhanced. GM1 did not induce neurite-like processes in MAP2-transfected cells. Treatment with cytochalasin B, which is reported to result in process formation, also did not induce neurite-like processes. These studies suggest that GM1's ability to mobilize MAP2 and promote its association with actin is not restricted to neurons.

Indium-111 chloride imaging in the detection of infected prostheses.

Thirty-three patients with painful joint prostheses and a suspicion of infection were imaged with [111In]chloride. A final diagnosis was established by culture in 19. Of these, 12 were categorized as true positives and three as true negatives. There were two false-positive studies, occurring in patients with knee prostheses. In both, the culture was obtained by aspiration. Two false negatives were in patients with hip prostheses, one of whom had been on long-term antibiotic suppressive therapy. The sensitivity was 86%, specificity 60%, and accuracy 79%. Seventeen of the proven cases had bone imaging prior to [111In]chloride imaging. All 17 static images were positive and were not helpful in differentiating loosening from infection. Using increased uptake on the blood-pool image as a criteria for infection, the sensitivity was 89%, but the specificity was 0. Adding flow studies made little difference in interpreting the blood-pool images. This study shows that [111In]chloride accurate in evaluating infection in prosthesis than bone imaging.

Indium-111 chloride imaging in chronic osteomyelitis.

Sixty-eight patients with clinically suspected chronic osteomyelitis were studied with [111In]chloride. Fifty-four images were categorized as true positive; seven were categorized as true negative. There were four false-positive studies, two of which were associated with healing cancellous bone grafts. There were three false-negative studies in patients previously treated with long-term antibiotic therapy. Images in eight noninfected healing fractures 3 to 8 mo old were normal. Three patients with infected total hip prostheses had positive images. Two patients with loose prostheses had negative images. This study shows that [111In]chloride imaging is an accurate way to localize chronic osteomyelitis and may overcome some of the disadvantages of [67Ga]citrate such as localization in noninfected healing fractures and in some loose [67Ga]citrate such as localization in noninfected healing fractures and in some loose prostheses.

Budd-Chiari syndrome and renal failure in Behcet disease. Report of a case and review of the literature.

A case of Behcet syndrome associated with three rare complications is presented. The patient initially presented with asymmetric polyarticular arthritis, subcutaneous nodules, conjunctivitis, and episcleritis. Necrotizing vasculitis and renal failure subsequently evolved. Despite immunosuppressive therapy, Budd-Chiari syndrome with high grade hepatic obstruction developed. A Denver shunt procedure failed to alter the terminal course. At postmortem examination, skin lesions, carditis, hepatic vein thrombosis, gastric ulcerations, and focal proliferative glomerulonephritis were found. The immunoglobulins and complement present in skin and renal tissue suggest an immune complex pathogenesis.

Tc-99m MDP and indium-111 chloride scintigraphy in skeletal tuberculosis.

A case of diffuse osseous tuberculosis with changes on skeletal Tc-99m methylene diphosphonate (MDP) and indium-111 chloride scintigraphy is presented. Only two other cases of bone scan findings in osseous tuberculosis (TB) were reported in the literature and both show patterns similar to diffuse metastatic disease. In addition, the demonstration of corresponding areas of decreased tracer activity on indium-111 bone marrow scintigraphy is a finding that has not been previously reported for skeletal tuberculosis.

Mucociliary clearance of deposited particles from the human lung: intra- and inter-subject reproductivity, total and regional lung clearance, and model comparisons.

The intra- and inter-subject reproducibility of pulmonary mucociliary clearance was investigated in nine healthy male subjects following deposition of an aerosol of 7.9 microns aerodynamic diameter iron oxide particles labeled with TC-99m. The results have been analyzed for both total bronchial clearance and for clearance from areas representing central (Zone I), mid (Zone II), and peripheral (Zone III) regions of the lung. The observed clearance rates were compared to the predictions of a mathematical model for lung clearance based on Weibel's dicotomous branching system. The results for total bronchial clearance showed an average TB120 (percent cleared in 2 hr) of 57%, while the average TB120 for Zone I, II, and III was 56%, 62%, and 48%, respectively. The mean half-times (times required to clear 50% of the deposited activity) for the total bronchial clearance and for Zones I, II, and III were 1.90 hr, 1.97 hr, and 1.70 hr and 2.62 hr, respectively. Total bronchial and regional clearance was reproducible (P = .05) within subjects, but significant variation was observed among subjects. The predictions of the mathematical model for total bronchial clearance are in good agreement with the experimental results. However, the experimental clearance rate was slower in Zone I, and faster in Zone II and III than is predicted by the model. The implications of these results are discussed.