T cell lymphoproliferative disorders associated with anti-tumor necrosis factor alpha antibody therapy for ulcerative colitis: literature summary

The enhanced risk of development of lymphoproliferative disorders in patients with inflammatory bowel disease has been attributed to immunosuppressive/immunomodulatory therapies. Infliximab is a chimeric monoclonal immunoglobulin G1 antibody directed against tumor necrosis factor alpha (TNF-α) that was approved by the Food and Drug Administration (FDA) in 1998 as an effective therapeutic agent against inflammatory bowel disease. Malignant lymphomas of both B and T cell lineage have been described in patients undergoing therapy involving TNF-α blockade. To date, eight cases of Epstein–Barr virus (EBV)-negative hepatosplenic T cell lymphoma associated with infliximab have been reported to the FDA’s Adverse Event Reporting System, as well as several other T cell lymphoproliferative disorders with aggressive clinical outcomes. We present the histologic, immunophenotypic, and molecular features of a T cell lymphoproliferative disorder involving the axillary lymph node of a 33-year-old male following infliximab treatment for ulcerative colitis. These EBV-negative lymphomas suggest that lymphoproliferative disorders following infliximab treatment for inflammatory bowel disease may involve EBV-independent immune dysregulation. The spectrum of lymphoproliferative disorders associated with infliximab and the potential mechanisms by which they occur are discussed

Gas density effects on dual-bell transition behavior

The concept of dual-bell nozzle, first proposed by Foster and Cowles in 1949 [1] has received renewed attention in recent years due to its one-step altitude adaptation capability [1-6]. This concept uses two shortened nozzles combined into one with a bump or inflection point between them, as shown in Fig. 1. During ascent it functions first at the lower area-ratio with controlled flow separation occurring at the inflection point, Fig. 1 (a). While the lower area-ratio helps to achieve high sea-level thrust, a controlled and symmetrical flow separation helps avoid dangerous side-loads. As the altitude increases and the gases expand further, the flow undergoes a transition process during which the flow jumps downstream and attaches itself close to the nozzle exit, with the flow filling the full nozzle exit section thereby utilizing the full geometrical area-ratio, Fig. 1 (b). Because of the higher area-ratios that are achievable through this design, a higher vacuum performance is feasible. Despite the losses associated with this design (such as aspiration drag in low altitude mode, non-optimum contour in high altitude mode, etc. [6]), the dual-bell nozzle shows better overall performance than a single bell nozzle of similar area-rati

Experimental study of wall pressure in afterbody flows with and without jet

Communication to : 33rd AIAA fluid dynamics conference and exhibit, Orlando (USA), 23-26 juin 2003SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.2003 n.147 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Wall pressure and thrust of a dual bell nozzle in a cold gas facility

A dual-bell nozzle has been tested in the ONERA-R2Ch wind tunnel within the CNES PERSEUS program. The wall pressure distributions and the thrust for the two flow regimes have been characterized in the nozzle pressure ratio (NPR) range from 51 up to 597. A hysteresis on the transition NPR between the two flow regimes has been observed according to the evolution of NPR. The duration for the switch between the two flow regimes is less than 10 ms. The hysteresis of about 20% on the NPR has also a direct effect on the thrust. The total thrust of the dual-bell nozzle becomes higher than the thrust of the isolated base nozzle without extension for NPR > 1500. The hysteresis phenomenon has been modeled with the use of supersonic separation criteria and by making the assumption that incipient separation occurs immediately after the transition for increasing NPRs, while effective separation occurs just before the transition for decreasing NPRs