Herbert Conway

PULSATILE ACTIVITY IN TOTAL TRANSPLANATION OF FETAL MOUSE HEARTS

In order to have a means of determining the length of time that individual cells of a homograft may remain viable, we have used the fetal heart as our experimental tissue. The pulsations of the homografted heart, as observed in the transparent chamber, provide a ready means of identification of the transplanted cells and also serve as an unquestionable indicator of their viability. The cessation of the pulsations is a clear-cut end point of the survival time of the graft. In this paper we present the technique of transplanting fetal hearts and describe the methods employed in their study. We also present observations based on the study of transplanted hearts and data on the survival time of grafted cells. Some preliminary data on the experimental treatment of homografted hearts are also included. While these studies were in progress Poor,’ a t Boston University, Boston, Mass., published a preliminary report on the homotransplantation of fetal hearts in the hamster.

One-stage push-back operation for congenital insufficiency of the palate

Abstract An additional operative step in the technique of the push-back operation for congenitally short palate is described. This step consists of the removal of a portion of the posterior wall of the bony pterygopalatine canal, thus permitting easy backward displacement of the mucoperiosteal flap and the soft palate. By this step the blood supply and inervation of the palate are preserved. The procedure permits satisfactory lengthening of the palate by a one-stage operation. The operation may be applied to cases in which there is congenital insufficiency of the palate without cleft as well as to cases in which there is shortening of the palate in association with incomplete or complete clefts.

Dye differentiation of injured tissues in burn injury.

The problem of differentiating between potentially viable and irreversibly damaged tissue in burn injury has challenged the imagination and ingenuity of many investigators. The appearance of the kdund, alterations in sensation,2 the distribution of intravascular fluorescein, or radioactive phosphorous4 and differential surface staining properties5 have all been tried and described as aids in diagnosis. Sevitt has clearly demonstrated and described the pitfalls involved in any assay based on wound appearance.F Briefly, the appearance of the burned wound varies with the type of thermal insult, the temperature of the insult, the duration of the insult, and, in the case of contact burns, the pressure during contact. Alterations in sensation depend on patient response which can be very variable and, under conditions of stress, not very reliable. Furthermore, the sensation of the skin varies in different parts of the body for it is influenced by the number of nerve endings as well as the dimensions of the skin. The intravascular injection of fluorescein or radioactive phosphorous permits one to map out an area of the body surface where vascular flow has been impeded, but these techniques, at best, give only a rough measure of the surface involved and no measure of the depth. Burn injury is a three-dimensional phenomenon. A test for assaying viability must give a n index of depth as well as the surface dimensions of the area involved. In an earlier paper we described the use of intravascular Evans Blue as an aid to diagnosis in burn i n j ~ r y . ~ This dye, by firmly binding with plasma protein, is retained largely in the vascular compartment. In injured areas where the circulation is still intact, it effuses along with plasma protein and fluid into the extracellular space. Here it combines as firmly with tissue proteins and remains for weeks or months. From the margins of viable tissue it slowly infiltrates into adjoining dead tissues, thus eventually obscuring the earlier discreet differentiation. Although Evans Blue worked well in delineating limited burns of the contact variety, it was of little value in more generalized burns of varying depth as sustained from flame, scald or steam injuries. The reason for failure stemmed from the fact that Evans Blue once deposited in the tissues, remained there for very long periods. Since extent of tissue death following burn injury can change for varying periods of time influenced by slowing of the circulation, thromboses, edema, infection, etc., Evans Blue was providing information at only a single timc in the sequence of events following injury. Its distribution, therefore, was not necessarily an index of the ultimate outcome. What was needed was a dye that was so rapidly distributed and removed from the body that one could follow, by the changes taking place in its turnover and by repeated injections, the changing quality of the burn injury.