Tumor necrosis factor alpha-induced endothelial tissue factor is located on the cell surface rather than in the subendothelial matrix

Because there is no consensus regarding the precise distribution of induced endothelial tissue factor (TF), we studied TF activity in and on tumor necrosis factor alpha-stimulated cultured human umbilical vein endothelial cells (ECs) and their underlying matrix. TF was mainly expressed on the cell surface. Only small traces were found on the apical surface suggesting that TF is predominantly located on the basolateral side of the cell membrane. The presence of TF on the cell surface was confirmed by flow cytometry. Subendothelial TF activity appeared to be dependent upon the procedure used to remove the stimulated EC monolayer. Whereas ammonium hydroxide or hypotonic lysis resulted in relatively high levels of matrix-associated TF, virtually no TF was found on the matrix after mild enzymatic detachment of stimulated ECs. Cell removal with EDTA resulted in intermediate levels of matrix-associated TF. Neither the enzymatic treatment nor EDTA degraded or removed this TF activity. Similar patterns were observed for matrix-associated TF antigen and EC surface markers. Electron microscopic analysis showed cell fragments on the matrix after monolayer lysis. The findings strongly suggest that induced endothelial TF associated with the subendothelial matrix actually represents TF on EC remnants.     

Early results of a prospective study on the pyrolytic carbon (pyrocarbon) Amandys? for osteoarthritis of the wrist

INTRODUCTION

The preliminary results of a pyrocarbon interpositional radiocarpal implant in a small cohort of patients were reviewed. As it is currently only a limited release product, we describe to potential users early complications and negative outcomes.

METHODS

Patients were assessed using pain levels, ranges of motion, grip strength, type of and time to return to work as well as pre-operative and post-operative DASH (Disabilities of the Arm, Shoulder and Hand) scores. Radiographs were taken and patient satisfaction was recorded.

RESULTS

All six patients were contacted. One was not satisfied. Three had reduced motion. None experienced squeaking. There were no immediate or late post-operative complications. There was one early volar displacement of an implant.

CONCLUSIONS

Although our early results are somewhat encouraging, further and longer studies are warranted before supporting the use of this particular pyrocarbon implant as a primary procedure.     

Prevention of transfusion-associated graft-versus-host disease: selection of an adequate dose of gamma radiation

To determine the optimal dose of gamma radiation necessary to inhibit T- lymphocyte function and prevent transfusion-acquired graft-versus-host disease (TA-GVHD), a donor plateletpheresis component was initially divided into ten 20-mL samples. One sample was not irradiated, while the other nine samples were treated with gamma radiation at doses ranging from 500 to 4500 cGy. T-lymphocyte function was subsequently measured by mixed lymphocyte cultures and mitogen stimulation assays. The results were assessed in each test by calculating the percentage of inhibition of each irradiated sample as compared to that of the unirradiated sample. The accuracy of the delivered dose of gamma radiation was measured with thermoluminescent dosimeters. It was concluded that a nominal dose of 3000 cGy (actual dose delivered, 2898 cGy) is the appropriate amount of gamma radiation needed to eliminate T- lymphocyte-mediated graft-versus-host disease.     

The angiomatous polyp and the angiofibroma: two different lesions

Five cases of angiomatous polyps that were initially interpreted as angiofibromas are presented. Although they are similar to angiofibromas, angiomatous polyps have a distinctly different pattern of growth on computed tomography and a different angiographic appearance. In addition, they are more easily extirpated at surgery than are angiofibromas.