PubMed Health⌕ Search

Biomedical subjects

A Mikulski

Publications and source records attributed to A Mikulski.

5 recordsLinked to original sources
PubMed1979

Solubilized and insolubilized bone morphogenetic protein.

A bone morphogenetic protein (BMP) obtained in solution by digestion of demineralized rabbit cortical bone matrix with bacterial collagenase retains its biologically active conformation in a neutral salt/ethylene glycol mixture. BMP may be insolubilized by coprecipitation with calcium phosphate and resolubilized by chemical extraction with a neutral salt in the same solvent mixture. Upon concanavalin A-Sepharose chromatography, BMP is bound by hydrophobic interaction and carbohydrate recognition and is recovered by elution with either alpha-methyl mannoside or ethylene glycol solvent mixture. Implants of both eluates and the extracts of the coprecipitate in double-walled diffusion chambers induce transmembrane bone morphogenesis. BMP is not species specific; rabbit BMP induces new bone formation in the rat. The present observations indicate that BMP is a glycoprotein.

Animals↗
PubMed1977

Noncollagenous proteins of a rat dentin matrix possessing bone morphogenetic activity.

An insoluble preparation of rat dentin matrix was shown to possess bone morphogenetic protein (BMP) activity, i.e. the capacity to induce the formation of catilage and bone when implanted intramuscularly. Since BMP activity was previously attributed to noncollagenous proteins (NCP) of bone and dentin, the nature of NCP of the rat dentin was examined. After treatment of the matrix with purified bacterial collagenase, three NCP were solubilized concomitantly with digestion of the dentin collagen to smaller peptides. The three proteins were separated by anion-exchange chromatography on DEAE-cellulose. Two of the NCP were rich in asparate, glutamate, glycine, serine, and alanine, and thus displayed compositions similar to acidic proteins of other connective tissues. The third NCP was shown by amino acid composition to be the aspartate, serine-rich phosphoprotein, which occurs mostly in a soluble form in rat dentin. This observation supports the view that a portion of dentin phosphotprotein is firmly bound.

Amino Acids↗
PubMed1975

Reversible extinction of the morphogen in bone matrix by reduction and oxidation of disulfide bonds.

Beta-Mercaptoethanol (beta-ME) or dithiothreitol (DTT) reduction extinguishes the capacity of bone matrix gelatin to produce new bone following implantation in a muscle pouch. If the reducing solution is used in concentrations of 50 mmoles/l or less, the extinction can be partially reversed by bubbling of oxygen through the solution for one hour. Sulfhydryl group blocking reagents prevent reoxidation of reduced bone gelatin, and restoration of the bone morphogenetic property (BMP). Unspecific borohydride reduction at 37 degrees destroys bone yield irreversibly, but at 2 degrees reduction of free aldehyde groups in bone gelatin does not prevent beta-ME and DTT reversible extinction. These observations are interpreted to suggest that the disulphide linkage may be an essential part of the biologically active conformation of either a non-collagenous bone morphogenetic polypeptide firmly bound to collagen or a collagen by-product entrapped within a water insoluble gel matrix.

Animals↗
PubMed1975

A chemosterilized antigen-extracted autodigested alloimplant for bone banks.

Limited chemical extraction of hydrophobic glycopeptides and subtotal autodigestion of the donor's cells and plasma membranes in undemineralized cortical bone in vitro reduces the putative quantity of haptenic substances absorbed by the recipient. Iodoacetic acid and sodium azide or other sulfhydryl group enzyme inhibitors added to the buffer solutions during in vitro autodigestion and estraction of intracellular alloantigens protects the bone matrix morphogenetic property against enzymatic degradation. The delayed hypersensitivity reaction induced by aseptically collected freeze-dried bone and the destruction of the bone morphogenetic property caused by radiation-sterilization is avoidable by sequential chemodigestion and chemosterilization of bone that preserves the maximum morphogenetic potential while transferring a minimum quantity of alloantigen.

Animals↗