Studies in calcification The reaction of some hard- and soft-tissue collagens with 1-fluoro-2:4-dinitrobenzene*

Role of carboxylic organic molecules in interfibrillar collagen mineralization

Bone is a composite material made up of inorganic and organic counterparts. Most of the inorganic counterpart accounts for calcium phosphate (CaP) whereas the major organic part is composed of collagen. The interfibrillar mineralization of collagen is an important step in the biomineralization of bone and tooth. Studies have shown that synthetic CaP undergoes auto-transformation to apatite nanocrystals before entering the gap zone of collagen. Also, the synthetic amorphous calcium phosphate/collagen combination alone is not capable of initiating apatite nucleation rapidly. Therefore, it was understood that there is the presence of a nucleation catalyst obstructing the auto-transformation of CaP before entering the collagen gap zone and initiating rapid nucleation after entering the collagen gap zone. Therefore, studies were focused on finding the nucleation catalyst responsible for the regulation of interfibrillar collagen mineralization. Organic macromolecules and low-molecular-weight carboxylic compounds are predominantly present in the bone and tooth. These organic compounds can interact with both apatite and collagen. Adsorption of the organic compounds on the apatite nanocrystal governs the nucleation, crystal growth, lattice orientation, particle size, and distribution. Additionally, they prevent the auto-transformation of CaP into apatite before entering the interfibrillar compartment of the collagen fibril. Therefore, many carboxylic organic compounds have been utilized in developing CaP. In this review, we have covered different carboxylate organic compounds governing collagen interfibrillar mineralization.

Factors Influencing the Remineralization of Dental Calculus

SYNOPSIS IN INTERLINGUA

FACTORES DE INFLUENTIA IN LE REMINERALISATION DE CALCULO DENTAL.-Esseva studiate le signification de Ca, P, K, Na, μ, CO2, pH, temperatura (4,25 e 37,5 C) e pressura (760 e 190 mm de Hg) como factores de influentia in le remineralisation del matrice organic de calculo dental e in le formation possible de un "placa" precursori. Matrices dividite in medietates in un solution o sub conditiones de cognoscite reactivitate serviva como controlos.

Le studios indicava que supra un Ca X P (mg %)2 de 35 remineralisation occurreva si o non CO2 esseva presente. Infra un Ca X P (mg %)2 de 35, le induction del remineralisation requireva le presentia de CO2. Na a un alte μ promoveva le remineralisation. Quando le pH esseva reducite, un temperatura de 37,5 esseva plus efficace que un temperatura de 25 C. A un pression de 756 mm de Hg, le remineralisation esseva nodular intra e super le matrice (Ca:P de 2,0). A 190 mm, remineralisation occurreva in omne partes del matrice.

Composition of epiphyseal cartilage. V. Amino acid and amino sugar composition of epiphyseal cartilage of rachitic chicks; changes effected by vitamin D-3

Nineteen amino acids and two amino sugars were identified in the epiphyseal cartilage of rachitic chicks, and their levels estimated. Investigation of the effect of oral administration of vitamin D3on the levels of these amino acids and amino sugars showed that vitamin D3increased significantly the levels of galactosamine and decreased the levels of hydroxyproline and of glycine. The decrease in the levels of proline and cystine and increase in that of methionine were not statistically significant.