Abraham Rapoport

Metabolic studies in prolonged fasting

Abstract Thirteen obese females were studied during 14 periods of fasting, lasting 2 to 4 weeks, in which they consumed only noncaloric fluids. This paper concerns itself primarily with changes in weight, in fluid-electrolyte and acid-base balance and in kidney function. The 11 patients who underwent 3 weeks of fasting lost an average of 12.7 pounds in the first week, 6.8 pounds in the second and 5.6 pounds in the third. The decreasing rate of weight loss with time could be related to decreases in urine output, basal metabolism and in activity of the patients. Urine sodium decreased gradually to about 20 mEq./day after 1 week of starvation. During early refeeding, urine sodium almost disappeared regardless of sodium intake and weight gain paralleled sodium retention. Urine chloride paralleled urine sodium whereas urine potassium fell more slowly although progressively. In 1 subject the aldosterone secretion rate which doubled after 1 week of fasting rose to its highest level during refeeding. Mild metabolic acidosis predominated in the first 2 weeks of fasting, a tendency to respiratory alkalosis in the third and metabolic alkalosis during refeeding. The clearances of urea and endogenous creatinine decreased during fasting. Data on urine pH, titratable acidity, ammonia, phosphorus and nitrogen are shown.

Influence of posture on the serum concentration of calcium

Abstract Experiments were designed to study the effects of change in posture on the serum concentrations of total calcium, plasma ionic calcium, magnesium, protein-bound calcium, total protein, albumin, and globulin. Plasma ionic calcium and serum magnesium were not influenced by changes in posture. All the remaining constituents responded in a consistent manner, namely, on changing from the lying to the erect position, their concentrations rose significantly. On sitting or on lying down, their values fell reaching minimal levels after about 1 2 hr and showing little change thereafter. All the values attained on lying were significantly lower than those reached on sitting in the same time periods. Variations in the concentrations of calcium and protein due to alteration in posture could amount to as much as 47% and 71%, respectively, of their normal range spans. These variations were considerably reduced by the use of protein corrections developed by Dent and in particular by Parfitt. A sex difference was noted in the concentrations of both serum total calcium and total protein, more marked in the latter. The difference in calcium appears due to a difference in its protein-bound component. It is clear that the influence of posture must be considered when interpreting serum calcium concentrations. Failure to recognize this influence has undoubtedly contributed to the variations in the normal ranges of serum calcium proposed by different workers.

• Periosteal New Bone Formation (Periosteal Neostosis) in Renal Osteodystrophy Relationship to Osteosclerosis, Osteitis Fibrosa, and Osteoid Excess!

Radiologic skeletal surveys in 117 patients with severe chronic renal disease revealed periosteal neostosis (periosteal new bone formation) in 10 patients (8.5%). Periosteal neostosis occurred in varied locations and was always accompanied by subperiosteal resorption in finger bones, and in 9 of 10 cases by osteosclerotic changes in the central skeleton. The most common finding in iliac crest biopsies, obtained from 8 patients, was osteoid excess (osteomalacia). The combination of periosteal neostosis, subperiosteal resorption, osteosclerosis, and osteoid excess may be a manifestation of secondary hyperparathyroidism, with high bone turnover and sustained ability to produce mineralized bone.

Pericarditis in patients undergoing long-term hemodialysis and peritoneal dialysis. Incidence, complications and management.

Abstract A retrospective review of 99 patients undergoing long-term hemodialysis and 119 patients undergoing long-term peritoneal dialysis between 1966 and 1974 revealed 43 episodes of pericarditis in 43 patients, an over-all incidence of 20 per cent. In 27 of the total 218 patients (12.4 per cent) pericarditis developed prior to or within two months of starting dialysis. In 12 of 99 patients (12.1 per cent) pericarditis developed after they had been undergoing hemodialysis for more than four months, whereas in only four of 119 patients (3.4 per cent) did pericarditis develop after they had been subjected to peritoneal dialysis for more than four months; this difference did not reach statistical significance. There was no significant difference between mean blood urea nitrogen and serum creatinine levels in patients with or without pericarditis. Patients with pericarditis had significantly higher reticulocyte counts (p On the basis of this study we advocate pericardial surgery only for the rare occasions of recurrent cardiac tamponade. We recommend needle pericardiocenteses for the initial treatment of pericardial effusion without tamponade or as a diagnostic procedure. In pericardial effusion without tamponade the pericarditis can be expected to resolve with conservative management.

Metabolic studies in prolonged fasting: II. Organic metabolism☆

Abstract Thirteen obese women were studied during 14 periods of fasting, lasting 2 to 4 weeks, in which they consumed only noncaloric fluids. This paper deals primarily with changes in certain aspects of their organic metabolism. Urine citrate decreased markedly while serum citrate, measured in one subject, rose. Similarly urine urate fell during fasting while serum urate increased. Ketones appeared in both the urine and serum during fasting but, in most patients, reached a plateau as the fast continued. Morning blood sugars reached minimum values in the first week of fasting, then gradually rose to average values higher than base line by the end of the third fasting week. Urine 17-hydroxycorticosteroids and 17 ketosteroids fell during fasting while, in one subject, the plasma 17 hydroxycorticosteroids (17 OHC) increased. Evidence is presented that the increase in plasma 17 OHC does not signify an increase in biological activity. Concentrations of serum total protein and albumin rose in the first week in some fasted subjects while those of serum gamma globulin remained unchanged. No significant change occurred in serum glutamic-oxalacetic transaminase during fasting while serum alkaline phosphatase appeared to decrease slightly.

The renal excretion of hydrogen ion in uric acid stone formers.

Abstract Renal hydrogen ion excretion was examined in 16 patients with uric acid calculi and in 2 control groups, the first consisting of 16 patients with calcium oxalate calculi and the second, 11 normal subjects. It was found that, both under basal conditions as well as during acid loading with ammonium chloride, patients with uric acid calculi tended to excrete urines of lower pH, lower ammonium and higher titratable acid than those forming oxalate stones. Not only was there a decrease in the absolute urine ammonium excretion of the uric acid stone formers but also the ammonium was low in relation to urine pH. Of 532 random urines tested in the uric acid group, before acid loading, 87.1 per cent had a pH 5.5 or less, compared to 37.1 per cent of 565 urines measured over the same pH range in the oxalate group. The defect responsible for the low urine pH and ammonia excretion in the uric acid group appeared to exert its effect primarily in the basal state since no difference was found, between the 2 stone-forming groups, in the increases of urine ammonia or in the decreases in urine pH during acid loading. It is suggested that the tendency of uric acid stone formers to excrete urines of consistently low pH contributes greatly to the pathogenesis of their stones. A rational explanation for the efficacy of alkalinization in the management of patients with uric acid calculi is provided by these findings.

Comparison of Two Methods for Measuring Activity Products of Calcium Salts in Urine

The degree of saturation of urine with calcium salts (either calcium phosphate or calcium oxalate) is an important factor in the pathogenesis of kidney stones (1). The determination of the state of saturation of urine with calcium salts provides an objective index by which to study the mode of action and efficiency of different therapeutic regimens designed to prevent recurrent stones (2).

Urinary Inhibitors of Calcification

Although it is accepted that urine contains different inhibitors of calcification (1, 2), no one has elucidated their role in the pathogenesis of kidney stones and demonstrated a consistent absence or decrease of any of the urine inhibitors with renal calculi (2–4).