Search PubMed⌕ Search

Biomedical subjects

H Lamendin

Publications and source records attributed to H Lamendin.

At least 37 records · Page 2Linked to original sources

Heterotopically induced osteogenesis in osteopetrotic rat mutants. A preliminary report.

Heterotopic osteogenesis was induced in three groups of Fatty Orl-op strain of rats, i.e., osteopetrotic (op/op) mutants, op/op mutants cured by previous transplants of normal bone marrow, and phenotypically normal littermates. Allogenic decalcified bone matrix was used as inductor. The osteopetrotic mutants from heterotopic ossicles containing bone and bone marrow under the influence of inductor. After four weeks the signs of remodelling processes of induced bone tissue are observed: osteoclasts are found in the Howship lacunae, and bone marrow is formed in the spaces adjacent to the bone trabeculae. The induced bone marrow contains megakaryocytes, cells of the erythropoietic and granulopoietic lines as well as some infiltrating lymphocytes. The important finding is that the amount and the histological structure of bone tissue and bone marrow induced heterotopically in the osteopetrotic animals were similar to that observed in both control groups. It is concluded that 1) osteopetrotic mutants have the same potency to form heterotopic bone tissue under the influence of inductor as the control animals, and 2) remodelling processes in four-week-old, induced ossicles are normal and differ in this respect from defective rebuilding of the orthotopic bones of op/op hosts.

Animals↗

[Superficial structure of dental cement as shown by acid etching and scanning electron microscope].

The superficial layer of the cement is made up of a mineralised structure in which are included organic fibres which would seem to serve as the intracemental anchorage of Sharpey's fibre. The appearance seen on sweep electron microscopy after acid demineralisation confirm those seen using the electron microscope by Selvig. These fibres included in the cement have a variable diameter ranging from a few microns and 45 microns on our pictures (10 microns according to Selvig). They consist of a numerous fibrils with a diameter of the order of 0.3 microns. In the cement these fibers are parallel to the surface of the tooth, this confirming Selvig's finding. Finally, our observations show that, in the superficial part of the cement, these fibres form a markedly flattened three-dimensional network.

Acid Etching, Dental↗

Comparative study on the composition of the organic matrix of the long bones of the "normal" rat and of the mutant Op/Orl.

The organic matrix of the long bones of the "normal" rat strain and of its mutant Op/Orl were investigated. This latter strain exhibits some anomalles similar to Albers-Schönberg disease as well as tooth retentions. Bones (tibia, femur) were incubated with 14C-glucose and also submitted to a fractional extraction procedure (EDTA, urea) to separate soluble and insoluble fractions. The proteins, hexoses, hexosamines, hydroxyproline content of these fractions was determined as well as the radioactivity of the soluble extracts Glycosaminoglycans were also studied by cellogel electrophoresis after pronase digestion of the EDTA-extracts. Male and female animals of each strain were studied separately. The relative amount of soluble proteins (EDTA + urea extracts) was the same in both strains, the mineral content of the final residue was however higher in the mutant Op/Orl strain. The hydroxyproline content of the mutant-extracts were lower than in the original strain suggesting a lower soluble collagen content. This may be due to a faster polymerisation, insolubillisation of freshly synthesised collagen. The hexosamine content of the mutant urea extracts and the final residue was higher than that found in the analogous extracts obtained from the normal "normal" strain, suggesting a higher proportion of structural glycoproteins in the mutant bone, uronic acid being low or absent. Some other parameters were identical between the mutant and original strains but differed between males and females. The radioactivity of the soluble extracts was higher in the males than in females. The glycosaminoglycans of the EDTA extracts are also different: male-extracts show two bands on cellogel electrophoresis, one corresponding to chondroitin-sulphate, the other to hyaluronate. Females showed only the chondroitin sulphate band. The aminoacid composition of the insoluble residue of males was higher in basic amino acids (lysine, histidine, arginine) than the female extracts. These results indicate the existence of discrete well defined differences between the organic matrix of the orginal and mutant strain on one side and between male and female bones on the other side.

Amino Acids↗

[Dental caries].

Explore the source record for details and available documents.

Dental Caries↗