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Biomedical subjects

H Löe

Publications and source records attributed to H Löe.

At least 109 records · Page 6Linked to original sources
PubMed1975

The role of gingival connective tissue in determining epithelial differentiation.

Free grafts of connective tissue, without epithelium, were transplanted from either the keratinized gingiva or the non-keratinized alveolar mucosa (controls) into areas of the alveolar mucosa in seven monkeys. The grafts were placed in pouches created in the connective tissue as close as possible to the overlying epithelium. After 3-4 weeks, the transplants were exposed by removal of the overlying tissue in order to allow epithelialization from the surrounding non-keratinized alveolar mucosa. The transplants were examined clinically and histologically at time peiods between 1 and 12 months. The gingival connective tissue grafts became covered with keratinized epithelium displaying the same characteristics as those of normal gingival epithelium. The alveolar mucosa transplants were covered with non-keratinized epithelium. This indicated that gingival connective tissue is capable of inducing the formation of a keratinized gingival epithelium.

Animals↗
PubMed1975

The fate of vital and devitalized bone grafts in the healing of interradicular lesions.

The fate of vital and devitalized grafts of mature concellous bone from the jaws were studied in interradicular lesions in monkeys. 98 bifurcation defects were produced in premolars and molars and maintained by periodontal dressing inserted for four weeks. Ten to 15 weeks later fresh cancellous bone was transplanted into 32 defects. Other cancellous bone grafts were divitalized by boiling and transplanted into 34 bifurcations. The remaining 32 defects received no grafts. The animals were sacrificed to yield observation periods from 0 to 90 days. After decalcification of the specimens and embedding in paraffin, serial sections were cut at 8 microns and stained. The fate of viable and dead transplants were similar during the healing of the interradicular lesions. Except for a few osteocytes which seemed to survive transplantation in the fresh cancellous bone, the osteocyte lacunae were devoid of cells in both types of transplants after 1 week. The deepest located bone grafts became incorporated in new bone developed from the interradicular septum. The more superficially located grafts were rejected or were surrounded by a cementum-like substans. The influence of the grafts on bone regeneration was small and based solely on their osteoconductive effect.

Animals↗
PubMed1975

The collagen content of skin and gingival tissues in ascorbic acid-deficient monkeys.

Five green monkeys were used in this study. Three animals were fed a scorbutigenic diet and the remaining two served as controls. Biopsies were dissected from the vestivular gingiva and dorsal skin and polyvinyl sponges were implanted subcutaneously during 4 week periods throughout the experimental period. The animals were sacrificed after 12 weeks and the periodontal ligament was removed. Collagen extracts were prepared from the gingival and granulation tissues and treated with bacterial collagenase. Following acid hydrolysis the total amount of proline and hydroxyproline was determined in various tissue preparations. In the tissues examined, the content of hydroxyproline decreased in the scorbutic animals throughout the experimental period. The decrease in the hydroxyproline content of the gingiva started within the first 4 weeks and was faster than that of the skin, indicating that the extent of decrease is dependent of the turnover rate of the collagen in the tissues. The synthesis of hydroxyproline was almost totally impaired in the granulation tissue formed in the sponges implanted after the 8th week of experimentation. Collagenase treatment of collagen extracts resulted in a release of proline and hydroxyproline in a higher ratio in extracts from the experimental animals than in extracts from the controls. It is concluded that ascorbic acid is a prerequisite for the maintenance of the collagen pool in the tissues and that lack of this vitamin results in the formation of a collagenase degradable protein fraction with a low hydroxyproline content.

Animals↗