James M. Burnell

Normal maturational changes in bone matrix, mineral, and crystal size in the rat

SummaryNormal rat bone maturation has been studied using biochemical methods and hydrazine separation of matrix and mineral for X-ray diffraction. In the bone, the amount of mineral increases between 4 and 22 weeks of age, while in the matrix, the ratio of noncollagenous protein to collagen progressively decreases. In mineral, in the absence of serum ion changes, growth in mean crystal size appears to be the determinant of the changing ratios of calcium, magnesium, carbonate, and phosphorus, and of the increasing mineral density.

The role of skeletal calcium deficiency in postmenopausal osteoporosis.

SummaryA previous study of iliac crest composition identified skeletal calcium deficiency in 25% of 56 postmenopausal osteoporotic patients evaluated prior to the use of stanozolol or calcitonin. This report is a follow-up of biopsy data after 2 years of treatment with drug or placebo in 31 patients, 11 of whom had skeletal calcium deficiency. The study diet, consisting of 1 g elemental calcium plus 400 U Vitamin D, repaired the skeletal calcium deficiency in all patients, treated and untreated alike. Total body calcium (TBC) results were influenced by separation into calcium deficient and normal mineral groups, apparent treatment response being observed largely in patients with calcium deficiency. It is suggested that if all postmenopausal women ingested 1 g elemental calcium plus 400 U Vitamin D daily, skeltal calcium deficiency in osteoporosis would disappear as a problem. Meanwhile, it is important to recognize that repair of calcium deficiency is an important variable capable of influencing bone response to therapy and the evaluation thereof.

Lack of Interference of Chloramphenicol with Penicillin in Hemolytic Streptococcal Infection in Mice

Summary 1. Mice were infected with group A streptococci and treated with chloramphenicol and penicillin, separately and in combination. Jawetzs observation that chloramphenicol interfered with penicillin when animals were given a single aqueous injection of both antibiotics was confirmed. 2. The interference was not demonstrable, however, when antibiotic blood levels were maintained for 2 or 3 days. Thus, despite early interference, the combination caused a progressive bactericidal action which, in conjunction with phagocytosis, protected the mice as well as penicillin alone. 3. These experiments imply that the phenomenon of antibiotic interference is seldom of clinical significance.

GASTRODIALYSIS IN THE TREATMENT OF ACUTE RENAL FAILURE

The objectives of dialysis in the management of acute renal failure include both correction and prevention of various electrolyte disorders and removal of nitrogenous products responsible for the uremic syndrome. In the past, gastric lavage has failed as a method of dialysis because of uncontrollable electrolyte transfers and loss of large amounts of dialysis fluid to the patient. The use of a cellophane bag, suggested originally by Schloerb (1, 2), has solved these problems and has made gastrodialysis technically possible. The theoretical advantage of a method of continuous dialysis as compared with intermittent dialysis offers great appeal in that it might be possible to obviate the major fluctuations in the uremic state inherent in intermittent dialysis. Further, if continuous dialysis were sufficiently effective in removing metabolic wastes, as well as in correcting electrolyte abnormalities, it might be possible to avoid the costly, time-consuming, highly technical procedure of hemodialysis or significantly decrease the number of hemodialyses necessary to sustain the patient through a period of renal failure. The present study was undertaken to evaluate the use of dialysis of the stomach as an adjunct in management of patients with acute renal failure. This paper describes a technique of gastrodialysis and the evaluation of this procedure in the treatment of twelve adults and two children.

The effects of crystal size distributions on the crystallinity analysis of bone mineral.

SummaryThe mechanisms by which crystal size distributions affect the usual method of quantitative X-ray diffraction analysis of bone mineral have been determined on synthetic crystals. It was observed that each component of a crystal-size distribution diffracts independently. This independence causes systematic nonlinear behavior in the plot of integrated intensity vs. broadening parameter curves. The nonlinearity resulted in an overestimation of the amount of nondiffracting material present in bone mineral. Because crystal size distributions may vary for different crystallographic directions, it is strongly suggested that the usual practice of adding thec-axis anda-axis integrated intensities to estimate the crystallinity of the sample be discontinued. Methods of understanding the crystal size distribution function in bone mineral are discussed and evaluated.

The problem of sodium and water needs of patients

Abstract An approach to the determination of sodium and water needs of patients has been developed on the principles that disorders of sodium balance are primarily extracellular volume disorders and that disorders of water balance are primarily osmolality disorders. The physiology of regulation and symptomatology support this view. A classification of disorders which implies therapy is presented, and the diagnosis and treatment of the various disorders are discussed.

Effectiveness of a new compound, benemid,® in elevating serum penicillin concentrations

The rapid renal clearance of penicillin has made it difficult to maintain blood levels adequate to combat resistant organisms such as enterococci and many staphylococci. Diodrast (1), p-amino-hippurate (PAH) (2), benzoic acid (3), sodium benzoate (3, 4), and carinamide (5), have been found to block renal tubular excretion of penicillin with enhancement of blood levels. Of these compounds, only carinamide has had wiedspread clinical use (6-8). Its value has been limited because the large doses required make it unwieldy and often poorly tolerated (9). This disadvantage appears to have been overcome by the recent discovery of a new compound, Benemid (10),1 which is apparently effective in low doses, and in preliminary studies has been found to have little toxicity (11). This report is based on measurements of penicillin blood levels in 74 patients treated with intramuscular penicillin G or its procaine salt.