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Native human carcinoembryonic antigen is rapidly removed from the circulation by the rat liver Kupffer cell after intravenous injection. The molecule is subsequently transferred to the hepatocyte in an immunologically identifiable form. Carcinoembryonic antigen has a circulatory half-life of 3.7 (+/- 0.8) min, and cellular entry is by receptor-mediated endocytosis. Non-specific fluid pinocytosis and phagocytosis can be excluded as possible mechanisms by the kinetics of clearance and failure of colloidal carbon to inhibit uptake. Substances with known affinity for the hepatic receptors for mannose, N-acetylglucosamine, fucose and galactose all fail to inhibit carcinoembryonic antigen clearance. After two cycles of the Smith degradation, carcinoembryonic antigen is still able to inhibit clearance of the native molecule. Receptor specificity is apparently not dependent on those non-reducing terminal sugars of the native molecule. Performic acid-oxidized carcinoembryonic antigen also inhibits clearance of carcinoembryonic antigen in vivo. Receptor binding is not dependent on tertiary protein conformation. Non-specific cross-reacting antigen, a glycoprotein structurally similar to carcinoembryonic antigen, is cleared by the same mechanism.

The addition of cholesterol and cholic acid to a diet containing 24 mg. percent of magnesium, an amount normally required for young rats, resulted in magnesium deficiency in rats. This was characterized by hyperexcitability, hyperemia of the ears, calcium deposition in the kidney tubules, low serum magnesium levels, and decreased oxidative phosphorylation of heart mitochondria. All these lesions were prevented by raising the dietary magnesium level four to eight times. Feeding the atherogenic diet produced the deposition of lipide in the aorta and in the heart valves. The extent of this intimal sudanophilia was reduced by large amounts of dietary magnesium although serum cholesterol values did not fall and usually rose. This represents perhaps the first clear cut disassociation between serum cholesterol values and the extent of intimal sudanophilia. Raising the level of dietary protein from 10 to 20 per cent decreased the serum cholesterol levels and the extent of the kidney lesions. Thyroxine administration lowered the serum cholesterol values, abolished the kidney lesions and reduced the intimal sudanophilia. These effects occurred even though the serum magnesium levels remained low.

Young male rats fed an atherogenic diet for 24 to 26 days developed magnesium deficiency. The renal lesions, calcium deposition in tubular lumens in the outer zona intermedia, are morphologically consistent with those seen in animals fed magnesium-free diets. It was necessary to feed 8 to 16 times the normal requirement of magnesium to prevent completely these lesions. The limitations in the pathogenesis of these renal lesions are discussed. The addition of 2 mg. per cent of thyroxine to the diet markedly lowered or abolished deposition of calcium in the kidney; it also lowered atherogenesis to a minimum but did not abolish it. Early lesions of atherosclerosis of the cardiac valves and of the aorta were observed. These were more prominent in animals on a 10 per cent than in those on a 20 per cent protein diet. The atherosclerosis was diminished but not abolished by exceedingly high dietary levels of magnesium in the 10 per cent protein group. Such a decrease was not noted in the 20 per cent protein group. There did not appear to be significant variation in the morphology of the fatty livers in and between the various groups and subgroups as judged by staining with Sudan IV.

The signs of obstruction of the superior vena cava have aroused clinical interest since Stokes1 described the syndrome over a century ago. The recent reviews of Ehrlich and others,2 Ochsner and Dixon3 and Hinshaw and Rutledge4 discussed in detail the anatomic and clinical manifestations of this disorder. A number of authors5 have described the findings on angiocardiography. The abnormal physical findings consist of striking venous engorgement, cyanosis and often edema, which are limited to the head, neck, arms and chest. Common complaints are headache, dizziness, fulness in the head, mental clouding and respiratory manifestations such as dyspnea, orthopnea and periodic breathing; in addition, paroxysmal dyspnea has been described by several authors,6 and Ferris7 reported "brief but severe attacks of hyperpnea" in 1 patient. The occurrence of respiratory symptoms in patients with stasis and with high venous pressure limited to the superior vena cava and its tributaries and with

Abdominal binders are used routinely after abdominal operations, and we have therefore studied the changes in pulmonary function caused by their application. The lung volume, its subdivisions and related aspects of pulmonary function have been measured before and after the application of abdominal swathes, and the possible relation of the findings to postoperative pulmonary complications has been considered. MATERIAL AND METHODS Studies were made on 8 subjects. Six subjects (1 to 6) were normal and ranged in age from 20 to 47 years; 3 (1, 5 and 6) were men. The other 2 subjects (7 and 8), respectively 53 and 59 years old, had pulmonary congestion due to chronic myocardial insufficiency; 1 (7) was a man. The method of Christie,1 slightly modified,2 was used, all measurements on normal subjects being made with the subject recumbent. In the patients with pulmonary congestion, the studies were made with the subject