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Biomedical subjects

A van den Hooff

Publications and source records attributed to A van den Hooff.

At least 37 records · Page 2Linked to original sources
PubMed1983

Cartilage tube formation by perichondrium: a new concept for tracheal reconstruction.

The formation of a cartilage tube by perichondrium around a silicone rod is described. Variables introduced in three experiments were (1) perichondrium of auricular elastic cartilage versus that of rib hyalin cartilage, (2) intramuscular versus subcutaneous insertion of the implants, and (3) the position of the chondrogenic layer of the perichondrium either facing the rod or facing outward. A stable and rigid cartilage tube with a smooth inner surface was obtained by using rib perichondrium preferably with the chondrogenic layer facing the rod. No differences between subcutaneous and intramuscular insertion of the transplants were noted.

Animals↗
PubMed1980

Tissue response to dense apatite implants in rats.

Dense (97-99.9%) hydroxylapatite ceramics were implanted in muscle and bone tissue of rats. The aim of this study was to compare apatite implant material made of commercially available powder with laboratory powder prepared in a painstaking manner. Biocompatibility, biostability, and adherence to bone were evaluated. In muscle tissue the implants were found to be encapsulated with a very thin connective tissue layer. Implantation in excavated bone tissue resulted with new bone directly deposited against the implant surface, irrespective of the type of hydroxylapatite used. When the implants were protruding from the bone surface, bone appeared to grow up to the edge of the protruding part of the implant. A very strong bonding developed; push-out tests indicated that the bone fractured but never at the interface. Histologic studies proved that a sleeve of newly formed bone closely encased the implant, regardless of shape. It was concluded that dense apatite ceramics are fully compatible with the tibia of the rat and that no degradation of the implant material occurred for intervals of up to 6 months after implantation. The very strong bonding without mechanical retention indicated continuity between artificial hydroxylapatite and natural bone. No difference was found between the biological behavior of the hydroxylapatites prepared from commercial or laboratory starting powders.

Animals↗
PubMed1978

The response of the living organism to dead and fixed dead enclosed homologous tissue.

Polyethylene tubes at both ends and with four perforations in the side walls were filled with untreated homologous necrotic muscle tissue or formaldehyde-fixed or glutaraldehyde-fixed homologous necrotic tissue and implanted subcutaneously in rats. The cell reaction in the tissues surrounding the differently filled tubes was examined. It was found that the inflammatory reaction to untreated necrotic homologous tissue was the least severe.

Aldehydes↗
PubMed1978

Short-term tissue reactions to enclosed glutaraldehyde-fixed tissue.

Polyethylene tubes closed at both ends and with four perforations in the sidewalls were filled with glutaraldehyde-fixed isologous tissue and implanted subcutaneously in rats. The cell reaction during the first 12 days in the tissues adjacent to the tubes was histologically examined. The reaction was compared to the reaction around tubes implanted empty. The examination showed a severe inflammatory reaction with probably immunologic aspects in the tissues adjacent to the filled tubes. The reaction around the empty tubes was slight and transient.

Aldehydes↗
PubMed1978

Response of the living organism to dead and fixed dead, enclosed isologous tissue.

Polyethylene tubes closed at both ends and with four perforations in the side walls were filled either with isologous muscle tissue or with formaldehyde-fixed or glutaraldehyde-fixed isologous tissue, and then implanted subcutaneously in rats. As controls, tubes with solutions of the fixatives were implanted. When cell reaction in the tissues surrounding the differently filled tubes was examined, the reaction to untreated necrotic tissue was found to be the least severe.

Aldehydes↗
PubMed1977

Fine structure of an end organ in the periodontal ligament of the mouse incisor.

Nerve endings were observed between collagen fiber bundles in the alveolar compartment of the periodontal ligament. In close relation to these endings, cells were observed with a rounded cell body from which cytoplasmic extensions protruded, each forming part of a sheath around the terminal region of a small nerve fiber. The nuclei of these cells occupied an eccentric position in the cytoplasm and were characterized by a typical kidney shape. In the cell's center a prominent Golgi complex was present. In the peripheral cytoplasm ladder-like structures with a periodicity of 160 nm were occasionally observed. The cell bodies were surrounded by a basal lamina, while the cytoplasmic extensions investing the nerve endings were surrounded by an envelope consisting of alternating electron dense and electron translucent layers containing material that stained with PAS and Alcian Blue. Where these envelopes bordered on the connective tissue, areas of filamentous material with a periodicity of 100-150 nm were occasionally found. The end organs may be considered to form part of a receptor system.

Animals↗
PubMed1977

Long-term results of the implantation of glutaraldehyde-fixed tissue.

Glutaraldehyde-fixed autologous young connective tissue was implanted in rabbits for periods of 4,6,8, and 12 months, respectively, to evaluate the long-term effects of glutaraldehyde fixation. It was concluded that the implants elicit very little reaction in the surrounding tissues and that the fixed tissue is slowly invaded by vital cells and probably evokes an immune response. It is likely that, although glutaraldehyde-fixed dead tissue provokes less reaction than both unfixed and formaldehyde-fixed dead tissue, in the long term it is also broken down and phagocytized.

Aldehydes↗