Changes in the plasma and urine levels of the trace metal zinc have been followed in a series of 37 adult patients totally supported by intravenous alimentation. Copper has also been determined in more recent cases. In such a seriously ill group, although urinary zinc loss may be very high at the height of catabolism, severe plasma depletion does not occur unless there is a subsequent phase of sustained anabolism and weight gain. In four patients plasma zinc fell to very low levels during this phase and three of this group developed a syndrome characterized by diarrhea, mental depression, para-nasal, oral and peri-oral dermatitis, and alopecia. The response to oral or intravenous zinc therapy is striking, except for hair regrowth which is delayed but eventually complete. The syndrome we have recognized in adult man has not been previously described. It resembles however the parakeratosis of zinc deficient swine and it is also very similar to Acrodermatitis enteropathica, a genetically determined disorder of infants very recently linked to zinc deficiency. Zinc is clearly essential to human metabolism and it should be included in all parenteral alimentation regimes particularly during the period of rapid, sustained, weight gain.

No abstract

Undamaged wheat starch granules were treated in water at 50°C for 72 hours, and their properties then compared with those of the parent starch before and after gelatinization. Some of their attributes suggest that little alteration has occurred, but changes in others indicate that the internal structure of the granule has been modified, increasing its heterogeneity in some respects, but reducing it in others. In particular, gelatinization occurs at a higher but much more sharply defined temperature as compared with the range of temperatures shown by the mixture of untreated granules.

The effect of metal cations on the swelling and gelatinization behaviour of large wheat starch granules has been studied by observing their behaviour in the presence of 24 different chlorides in aqueous solutions. With most salts, increasing concentration results in gelatinization temperatures being first raised, then depressed, and then raised again. Increasing salt concentration may also cause the initial loss of anisotropy to occur at the granule surface instead of at the hilum, and result in an apparent solution of starch rather than swollen granules. The gelatinization phenomena have been classified into three major types, and these are described in detail. It is suggested that both water and partially hydrated salts can act as gelling agents for starch granules, and that the interplay of these two agencies can explain the observed complex relation between gelatinization temperature and salt concentration.

A clinical test ofintestinal calcium absorption has been developed using non-radioactive stable strontium as a calcium tracer. In nine elderly subjects there was a close correlation between the fractional absorption of strontium and radioactive calcium (45Ca) during a five hour period after the simultaneous oral administration of the two tracers. Comparable precision was achieved with each tracer in six subjects in whom the test was repeated after two weeks. The effect of food on strontium absorption was examined in a further 33 normal subjects (age 21-60 years), and the administration ofthe strontium with a standard breakfast was shown to reduce the variance at individual time points. A simplified test in which serum strontium concentration was measured four hours after the oral dose given with a standard breakfast was adopted as the routine procedure. The normal range (mean (2 SD)), established over 97 tests in 53 patients, was 7*0-18-0% of the dose in the extracellular fluid. A further 30 patients with possible disorders of calcium absorption (10 with primary hyperparathyroidism and 20 with coeliac disease) were studied by this standard test. In both groups of patients the mean four hour strontium values were significantly different from normal.This standard strontium absorption test allows assessment of calcium absorption with sufficient sensitivity and precision to have a wide application in clinical practice. In an earlier study we showed a close correlation between serum 45Ca and stable strontium concentrations after an oral dose of the tracers given on consecutive days under fasting conditions in patients with various abnormalities of calcium metabolism.3 In this study we compared the simultaneous absorption of 45Ca and strontium in normal subjects and assessed the comparative precision of each test. To optimise and simplify the procedure we took serum samples for measurement at different times and studied the effect of a standard breakfast on the absorption oforal strontium. A modified strontium tracer test was then used to assess patients in whom intestinal calcium absorption was likely to be abnormal.