Irvin C. Plough

THE RELATION OF NITROGEN RETENTION TO NITROGEN INTAKE IN ADULTS WITH POST-TRAUMATIC MALNUTRITION

Over a wide range of nitrogen intake, proteindepleted (1, 2) or growing rats (3, 4) retain increasing amounts of nitrogen as the dietary nitrogen is raised provided adequate calories are fed. Malnourished (5) or normal children (6) also increase nitrogen retention as nitrogen intake is raised, although some exceptions have been noted (6, 7). In malnourished adults it is apparent that some similar relationship between nitrogen intake and nitrogen retention is also present. For several reasons, however, the relationship between nitrogen intake and nitrogen retention in malnourished adults has not been well defined. In most adult studies, for example, caloric intake has frequently been substantially altered along with variations in nitrogen intake (8-13). In view of the known effect of non-protein calories on nitrogen metabolism (14) such studies become quite difficult to interpret. Equally difficult to interpret are studies (7, 11, 15) in which fecal nitrogen analysis has been omitted. And finally it should be noted that in many instances study periods have been too short with no account taken of the variable time required for re-equilibration of nitrogen metabolism after a change in dietary nitrogen (9, 10, 16-21). In the present study, nitrogen retention was measured at various levels of nitrogen intake in a series of patients suffering from malnutrition after severe injury. In most of the patients at least two levels of nitrogen intake were employed, while caloric intake was kept constant. Balance periods were sufficiently long to allow for reequilibration of nitrogen metabolism after changes

Changes in serum proteins produced by infusions of dextran.

Summary Daily infusions of dextran were given to 13 patients for as long as 15 days. In addition to the decrease in total serum protein from plasma volume expansion, dextran was found to produce a relatively greater decrease in globulin than in albumin. Serum cholinesterase activity decreased, and zinc and thymol turbidity values fell.

Thyroid-Adrenocortical Interrelations: Failure to Demonstrate Antagonism Between Triiodo-thyronine and Hydrocortisone in Man

It is generally accepted that acute injury results in an outpouring of adrenocortical hormones 5 (1, 2), and that these hormones play an important role in the response of the total organism to such injury. The marked increase in urinary nitrogen excretion which characteristically occurs immediately following acute injury is usually considered to result from the catabolic action of the adrenocortical hormones on protein metabolism (3). Supporting this concept are recent studies correlating the negative nitrogen balance following surgical trauma in man with the rise in 17-hydroxysteroid excretion (4). The participation of the thyroid gland in the response to acute injury in man is less well delineated. Certain observations have suggested that there may be an increase in circulating thyroid hormone in man following trauma (5,6); other investigators have been unable to confirm this finding (7, 8). The role of the thyroid is particularly difficult to evaluate following injury because the increased output of adrenocortical hormones may affect some of the methods used to assay thyroid function (9-11 ), and may also tend to inhibit thyroid activity (9, 11-14). Goldenberg, Lutwak, Rosenbaum, and Hayes (15) have recently proposed that the catabolic response to injury is due primarily to excess thyroid hormone rather than adrenocortical hormones.