| 31. |
- Holgers, K M, et al.
(författare)
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Soft tissue reactions around percutaneous implants: a clinical study of soft tissue conditions around skin-penetrating titanium implants for bone-anchored hearing aids
- 1988
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Ingår i: American Journal of Otology. - 0192-9763. ; 9:1, s. 56-59
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Tidskriftsartikel (refereegranskat)abstract
- Some patients with hearing impairment cannot use conventional hearing aids. One solution for these patients is the use of bone conduction hearing aids; however, this kind of equipment is associated with several problems related to the necessity for a good contact between the transducer and the temporal bone. Direct bone contact would be an ideal solution provided that safe and reaction-free skin penetration and a safe and permanent bone anchorage could be achieved. Branemark et al have developed a procedure to furnish edentulous patients with fixed bridges using titanium implants. This report is focused on the clinical status of the soft tissue adjacent to the 67 skin-penetrating devices in 60 patients. The patients have been followed between 3 and 96 months on 313 occasions, which represents a total observation time of 1515 months of clinical performance. Only one implant was extracted due to adverse skin reaction, giving a failure rate of 0.07% per month. This is comparable with the failure rate of cardiac pacemakers 0.02-0.04% per month).
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| 32. |
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| 33. |
- Linder, L, et al.
(författare)
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Clinical aspects of osseointegration in joint replacement. A histological study of titanium implants
- 1988
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Ingår i: Journal of Bone and Joint Surgery: British Volume. - 2044-5377. ; 70-B:4, s. 550-555
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Tidskriftsartikel (refereegranskat)abstract
- In an experimental clinical study, 25 implants of pure titanium were inserted into the proximal tibia of 11 volunteer patients, four with rheumatoid arthritis and seven with osteoarthritis. The implants were removed from five weeks to 24 months later and detailed histological analysis was performed. The implants generally healed with direct bone-metal contact, showing so-called osseointegration. Only one of the 21 implants which had been in place for over five months did not show osseointegration, probably because of inadequate primary contact with bone. The presence of rheumatoid disease did not prevent osseointegration, but accompanying osteoporosis seemed to be a risk factor.
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| 34. |
- Löfgren, Anders, et al.
(författare)
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Copolymers of 1,5-dioxepan-2-one and L- or D,L-dilactide: in vivo degradation behaviour
- 1994
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Ingår i: Journal of Biomaterials Science. Polymer Edition. - 0920-5063. ; 6:5, s. 411-423
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Tidskriftsartikel (refereegranskat)abstract
- Copolymers of 1,5-dioxepan-2-one (DXO) and L- or D,L-dilactide have been synthesized and characterized. The molar ratio of the two monomers was around 20/80 of DXO and L- or D,L-lactide respectively. In vivo studies on rats revealed significant differences in tissue response between the semicrystalline DXO/L-LA copolymer and the amorphous DXO/D,L-LA copolymer. The materials were characterized pre- and post-implantation by size-exclusion chromatography (SEC), differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), and light-microscopy. Degradation seems to follow an autocatalytic hydrolysis mechanism. The amorphous copolymer was degraded at a faster rate and gave a less pronounced foreign body reaction as compared to the semicrystalline one.
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| 35. |
- Malmvall, B E, et al.
(författare)
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Immune complexes, rheumatoid factors, and cellular immunological parameters in patients with giant cell arteritis
- 1981
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Ingår i: Annals of the Rheumatic Diseases. - 1468-2060. ; 40:3, s. 276-280
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Tidskriftsartikel (refereegranskat)abstract
- Circulating immune complexes were found in 2 of 15 patients with giant cell arteritis (GCA) by using a solid phase Clq enzyme linked immunoabsorbent assay (ELISA). The prevalence in controls was 5%. Rheumatoid factor could be demonstrated in 2 out of 27 patients and in 11% of the controls by using a similar ELISA technique. The prevalence of T cells in blood was similar in 25 patients with GCA and in controls. The blood lymphocyte blastogenic response to the mitogens, phytohaemagglutinin, concanavalin-A, and pokeweed mitogen did not differ in 25 untreated patients compared with controls. Stimulation of lymphocytes by arterial homogenates was tested in 8 patients. In no case could a significant simulation by obtained. We conclude that immune complexes and rheumatoid factors are present in the same low frequency in GCA patients as in the normal population, and that the studied parameters of cellular immunity appear to be normal.
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| 36. |
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| 37. |
- Rosengren, Agneta, et al.
(författare)
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Analysis of the inflammatory response to titanium and PTFE implants in soft tissue by macrophage phenotype quantification
- 1998
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Ingår i: Journal of Materials Science: Materials in Medicine. - 1573-4838. ; 9:7, s. 415-420
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Tidskriftsartikel (refereegranskat)abstract
- Implants of commercially pure titanium and polytetrafluoroethylene (PTFE) were inserted in the rat abdominal wall for 1, 6 or 12 wk. The foreign body reaction was evaluated by immunohistochemical quantification of monocytes/macrophages and by the thickness of the foreign-body capsule. At all time intervals, the majority of interfacial cells were ED1-positive while ED2-positive cells were localized deeper in the tissue. Neither titanium nor PTFE displayed a significant change in capsule thickness over time. The total cell numbers decreased overtime for both types of material. At 12 wk the PTFE implants, compared to titanium, were surrounded by a significantly thicker reactive capsule with larger total cell numbers. No significant differences were seen in the macrophage subset response between the two types of implants. Thus, the present study showed differences between titanium and PTFE at 12 wk but not at earlier time points.
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| 38. |
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| 39. |
- Rosengren, Agneta, et al.
(författare)
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Inflammatory reaction dependence on implant localization in rat soft tissue models
- 1997
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Ingår i: Biomaterials. - 1878-5905. ; 18:14, s. 979-987
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Tidskriftsartikel (refereegranskat)abstract
- This study compares two different implantation models in soft tissue in rat abdominal wall with regard to inflammatory reactions. Titanium rods and discs, penetrating or not penetrating the peritoneal wall respectively, were implanted. After 3, 10 or 30 days the distribution of monocytes/macrophages and cytokines (interleukin-1 and transforming growth factor-beta) in the tissue adjacent to the implants was investigated under immunohistochemistry. The macrophage-specific antibody, ED1, was used for the identification of newly recruited macrophages and the ED2 antibody was used for the mature tissue macrophages. After 10 days the non-penetrating implants had a larger number of cells close to the implant than the penetrating implants. The opposite was seen after 30 days implantation, with a larger number of cells around the penetrating implants. At all time intervals the penetrating implants had a thicker reactive capsule. The cytokines interleukin-1beta and transforming growth factor-beta could be detected in the reactive tissue adjacent to both types of implants, without obvious differences for the two implant situations. The biocompatibility of a material appears to be influenced by the localization of the implant. In addition, it seems to be of importance to extend the follow-up periods further, as we cannot assume that steady state is reached at 30 days implantation.
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| 40. |
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