Bone Calcium Deposition Research Articles

FLUORIDE IN OTOSCLEROSIS-Reply

As senior author of the article referred to by Dr. Waldbott I invited a reply by Prof Alexandre Petrovic which follows my reply. Dr. Petrovic is director of the Tissue Culture Laboratory at Northwestern University and Chicago Wesley Memorial Hospital where he has been engaged in research on the effects of various doses of sodium fluoride on deposition of calcium in bone. Meanwhile, to quote from an editorial in theAmerican Journal of Diseases of Childrenfor December 1964: More evidence has been adduced to establish the fact that controlled amounts of fluorine in public water supplies are beneficial in lowering the caries rate than was ever assembled in behalf of the lowly toothbrush. There is no disputing the fact that overdosage with fluorine can be as harmful as overdosage with any of a great number of useful drugs, including aspirin, morphine, digitalis, and arsenic. Individual idiosyncrasies producing allergic symptoms

Bone metabolism and regulation of the blood calcium level in rats.

Combined kinetic (Ca45) and balance (Ca40) studies of young male Sprague-Dawley rats placed on three different levels of calcium intakes (0.05, 0.5, 1.0% Ca) showed that the blood plasma calcium level, as determined by atomic absorption spectrophotometry, remained constant and invariant over a range of absorption from 4.5 to 83.4 mg Ca/day and that the pool, i.e., all the exchangeable calcium in the body, did not increase with increased absorption. Hence no direct regulatory role can be attributed to the size of the pool. Measurement of the calcium deposition and resorption rates in bone showed that the former changed only little with increasing absorption, whereas the latter decreased nearly linearly under the same conditions. Calcium resorption from bone therefore appears to play the major role in regulating the blood calcium level.

Comparative metabolism of Sr89 and Ca45 by bone grown in vitro.

SummaryAn in vitro culturing technic was used in comparing metabolism of calcium-45 and strontium-89 in bone. The results of a large number of determinations indicated: a) that at 2 hrs bone contained 1.08 times as much strontium-89 as calcium-45; b) when exposed to constant levels of Sr89 and Ca45, the Observed Ratiobone-medium equilibrated at 0.83 within 7 days; c) strontium-89 was released from bone at a ratio of about 1.2 times that of calcium-45; d) addition of carrier strontium markedly inhibited the long term deposition of calcium in bone but the discriminatory mechanisms were unaltered.

PHOSPHATASE ACTIVITY IN CHRONIC ARTHRITIS

The presence of a ferment, phosphatase, in the bones of young rats was demonstrated by Robison¹in 1932. This ferment hydrolyzes the phosphoric esters of hexosephosphate, glycerophosphate and nucleoprotein. One of the resulting products of such hydrolysis is inorganic phosphorus. Therefore, this ferment plays an important role in the deposition of calcium in bone, in carbohydrate metabolism, in renal metabolism and indirectly in the maintenance of the proper hydrogen ion concentration of blood. Its ubiquitous nature in body tissues has been shown by Bodansky²and Kay.₃So complex are the physiologic functions of phosphatase that the complexity can be matched only by the chemical complexity of the liver itself. All investigators have found an increase of serum phosphatase in such diverse diseases as osteitis deformans,⁴hyperparathyroidism,⁵rickets⁵and obstructive jaundice.⁶The exact significance of this increase is unknown. Regarding other conditions, notably chronicatrophie arthritis and the healing of bone

Calcification, Decalcification, and Ossification: Part I

The problems of bone growth have for many years attracted the attention of physiologists, anatomists, and biochemists, and many controversies have centred on the nature of the osteoblast and the osteoclast, the function of the periosteum, the chemical constitution of the bone salt, and the factors determining the deposition of this salt in the skeletal framework. To the clinician and the surgeon these problems have appeared to be chiefly of academic interest, and in no other branch of medicine has there been more confused thought, more inaccurate observation, and more unsound teaching, than in the clinical pathology of ossification, calcification, and decalcification of tissues. Bone formation has been attributed to the specific activity of osteoblasts, despite the fact that bone may develop in tissues far distant from any possible source of osteoblasts. The deposition of calcium in abnormal situations has not been correlated with the deposition of calcium in normal bone, and special theories have been fo...

The Relation of Vitamin D to Deposition of Calcium in Bone.

Quantitative studies in our laboratory have shown that when the food of the growing animal (rat) includes a liberal allowance of vitamin D and a constant supply of phosphorus (0.42%), the calcium content of the bodies as determined at intervals during the period of growth is markedly influenced by the calcium content of the food, as varied in these experiments from 0.16 to 0.50% of calcium in the dry food mixture. In the present experiments we find further, that in rats receiving a basal diet containing a generous allowance of calcium and phosphorus in good proportions (calcium, 0.74%; phosphorus, 0.58%) but with the vitamin D supply restricted practically to a bodily store acquired by 21 to 28 days of age, the growing body has at a given age about the same calcium content as has been acquired by similar animals which received 0.32% calcium, 0.42% phosphorus, and a liberal supply of vitamin D. The calcium content of the femurs of rats which had been kept from the age of 21 or 28 days to the age of 56 days on the vitamin-D-deficient diet which we have previously described is about twice as high as in otherwise similar rats fed the high-calcium rickets-producing diet of Steenbock (No. 2965) for the same length of time. Our rats have not had rickets according to the criterion of the “line” test, yet the deposition of calcium in their growing bones has been influenced by the vitamin D content of the food, even though the percentages of calcium and phosphorus in the dry food mixtures were favorable and uniform. Graded amounts of vitamin D supplied in the form of whole (summer) milk powder induced graded increments in calcification up to what appears to be the maximum potential level.

DEPOSITION OF CALCIUM SALTS IN AREAS OF CALCIFICATION

In former papers I have reviewed evidence as to the manner of the transport of calcium salts in the blood stream and their deposition in bone and in calcified areas. The deposition of calcium in bone is in an extremely fine form and in such a manner that from appearances alone it might be interpreted according to the bias of the observer, either as a secretory phenomenon of the osteoblasts and bone cells or as a precipitation phenomenon. Correlated with physiologic evidence, however, the balance of proof is in favor of the secretory view. The object of this investigation, was to learn whether such was also the case in areas of calcification. In this paper I shall review the information I have obtained by the examination and study of various calcified areas, and shall discuss the conclusions to be made from the facts presented. MATERIAL All of the material used

EFFECTS OF RADIATIONS OF COD LIVER OIL

Cod liver oil, egg yolk and other naturally occurring foodstuffs are known to be curative of rickets. The radiations of ultraviolet light bring about same result. In 1923, Park, Powers and Guy 1 made statement that the similarity between action of cod liver oil and that of radiant energy in rickets is so close that a connection must exist between them. Kugelmass and McQuarrie 2 demonstrated that this connection existed by reason of ability of foodstuffs mentioned above to give off radiations of ultraviolet light. Kramer, Casparis and Howland 3 showed that both these agencies caused an increase in serum phosphorus and deposition of calcium in bone. It has been noted for some time that animals deprived of vitamin A develop infections of respiratory tract and very frequently a generalized pyogenic involvement, in which organisms of an avirulent type are etiologic agents.