CONCISE COMMUNICATIONS preciated; as much as a 30% suppression of immunoglobulin production has been reported (5,6). Beyond that, experiences with high-dose MTX used in malignant disorders have revealed marked immunosuppressive properties, including decreased antibody production (7).Discontinuation of MTX is most important in managing interstitial pneumonia due to CMV following low-dose weekly MTX in patients with RA. Our patient showed a good and satisfactory response after discontinuation of MTX, despite the commencement of steroid therapy, indicating stronger immunosuppressive properties of MTX than prednisolone. However, in other patients, respiratory CMV involvement may be more severe and therapy with ganciclovir should then be considered (8).

Silicon carbide possesses exceptional mechanical and thermal properties, but its densification by conventional sintering is often very difficult. In the present work, silicon carbide was consolidated by spark plasma sintering in the presence of alumina and yttria. The results pointed out that the use of a single oxide does not enhance the sintering kinetics significantly, while the contemporaneous addition of both oxides has a beneficial effect on densification, with a relative density increase of about 10%. Interestingly, the oxide doping allows to double the room‐temperature flexural strength.

The influence of die wall lubrication during warm die compaction on densification, microstructure and mechanical properties of three low alloy ferrous powders was investigated. Specimens were sintered at 1250°C. Die wall lubrication leads to higher green and sintered density and enhances the dimensional stability. It does not affect the microstructure of the matrix, while pores are smaller and more rounded than in bulk lubricated specimens. In TRS tests, both strength and deformation are higher in die wall lubricated specimens than bulk lubricated ones.