Cardiac arrest and bone cement.

Correspondence BJOUr that "after many attempts to find any small intact nerves, the search was abandoned." I am sure that in a case of this nature the dye would have enabled him to find most of these small intact nerves. In a personal communication to me on the use of leucomethylene blue to detect the vagal fibres, A. A. Gunn stated that in 65 truncal vagotomies done in 1970, in 54 of these operations he found further fibres following testing with leucomethylene blue; 75 of the fibres so removed proved vagal. There is, therefore, no doubt whatsoever that these additional fibres would not have been detected otherwise. I therefore submit that, although the leucomethylene blue dye is not, and I emphasize not, a test for completeness of vagotomy, it can be of considerable help in enabling the operator to detect the small nerve radicles, which he can then remove, thus ensuring that a satisfactory vagotomy is performed. The Burge machine is not easy to manipulate, and there are various factors which can upset its operative value.-I am, SIR,-Antilymphocytic serum (A.L.S.) of whatever provenance has been found to have antimacrophagic activity which impedes capillary migration of macrophages.1 Conflicting reports have appeared concerning the effect of A.L.S. on in-vivo carbon clearance with both suppression2 and no in-terference3 being found. Since this antimacrophagic activity might be of importance in determining A.L.S. immuno-suppressive capacity in vivo, experiments have been carried out to determine whether or not A.L.S. depresses phagocytic activity of macrophages in vitro. Adherent monolayers of normal guinea-pig peritoneal macrophages were allowed to form in a modified Sykes-Moore tissue culture chamber in a nutrient medium of TC 199 and 20% normal homologous serum. They were treated for varying periods up to eight days with 1 in 80 rabbit antiguinea-pig thymus serum (A.T.S.) after which car-bonyl iron powder was added to the chamber. The serum was one which gave a 90% inhibition of macrophage capillary migration.1 Treatment with the A.T.S. for these varying periods did not impair ability of these macrophages to take up the foreign particulate matter as compared to those untreated. Macrophages preserved their phagocytic activity even after eight days continuous pretreatment with A.T.S. while strongly aggregated throughout. Macrophage aggregation power of A.L.S. allied to migration inhibition activity thus appears to be divorced from a phagocytosis depressing action. The latter may indicate contamination of A.L.S. with antimacrophage serum4 perhaps related to the …