Evidence has been presented by several investigators that functional capacity of the kidney in the premature and young infant is lower than in older children and adults. Schoenthal (1) using urea clearance, McCance and Young (2) urea and inulin clearances, Barnett (3) inulin clearance, and

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The various components constituting the plasma protein complex have been characterized by many different chemical methods. Perhaps the most extensively used method of defining the component proteins has been by describing their solubility behavior in salt solutions. Thus, the terms fibrinogen, euglobulin, pseudoglobulin, and albumin have been applied, not to molecular species or chemical entities, but to the fractional parts of the total plasma protein complex, separated by precipitation at specified salt concentrations.In this study, the plasma protein fractions "salted out" by increasing concentrations of salt solution were quantitated in normal infants and children. The influence of maturity and age upon the concentration of the individual fractions precipitated was studied by examining and comparing the bloods of premature infants, full-term newborn infants, older infants, and children. The quantitative changes occurring during the course of various diseases, especially nephritis and nephrosis, were measured. METHODSThe phosphate salt mixture used by Butler et al. (1,2) in their study of the solubility curves of human plasma proteins was employed. These authors, using an equation derived by Cohn (3), obtained a discontinuous curve when the solubility of the protein expressed logarithmically was plotted against increasing concentrations of the phosphate precipitant. They stated that the breaks in the discontinuous curve were caused by successive precipitation of the progressively more soluble protein fractions.Briefly, the method entailed precipitation of the proteins at room temperature with increasing concentrations of a phosphate solution. The phosphate precipitant was made of equal parts of monobasic and dibasic potassium phosphate, so that the pH of the different concentrations employed was constant at 6.5. Blood was collected without I Aided by a grant from the Mead Johnson Company, Evansville, Indiana. stasis and allowed to clot. After centrifugation, the serum was separated. One volume of serum was added to 30 volumes of phosphate precipitant. (The different concentrations of phosphate precipitant were prepared from a stock 3 molar solution.). In actual practice, 0.2 cc. of serum was added to 6.0 cc. of phosphate solution; instead of filtrations as practiced by Butler et al. (1, 2), the precipitated protein was removed by centrifugation at 2,000 R.P.M. for 15 minutes in the angle centrifuge. Supernatant fluids were analyzed by the micro-Kjeldahl method. The concentrations of phosphate precipitant used with each serum ranged from 0.8 molar to 3.0 molar.Because there is, as indicated by Butler et al. (2), a lack of sharp breaks in the solubility curve of the serum proteins obtained by salt precipitation, we have recorded the absolute amount of protein (grams per 100 cc.) precipitated by each successive increase in salt concentrations of precipitant. In the interest of consistency, we have also designated in our tables the fractions precipitated by the Na,SO4 method of Howe (4)

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Examination of the records of patients with lead poisoning admitted to the Children's Hospital of Philadelphia revealed a seasonal incidence in the onset of encephalopathic symptoms. Figure 1 shows the monthly distribution of onset of symptoms of the patients with frank lead encephalopathy admitted to this hospital.In constructing this figure only patients with frank encephalopathic symptoms of rather acute onset were counted; patients with latent or subclinical plumbism, usually discovered accidentally, who exhibited no obvious encephalopathic symptoms were not included. It is apparent from figure 1 that almost all of the cases occur during the late spring and summer months. Shelling and Hopper 1 commented on the same seasonal incidence of the cases studied in the Harriet Lane Home.We assumed that there was a real relation, probably causal, between the summer season and the increased severity of lead poisoning and planned experiments to examine the seasonal factors which were possibly operative in determining this relation. In this investigation a study was made of the effect of two meteorologie phenomena, increased temperature and increased solar radiation, which occur during the summer season on the severity of lead poisoning in rats. EXPERIMENTAL STUDYAlbino rats raised in our laboratory colony were used in all experiments. Rats weighing in the neighborhood of 60 to 100 Gm. were selected, for we had found that it was difficult to produce appreciable poisoning in heavier animals