| 1. |
- Lundberg, Fredrik, et al.
(författare)
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Presence of vitronectin and activated complement factor C9 on ventriculoperitoneal shunts and temporary ventricular drainage catheters
- 1999
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Ingår i: Journal of Neurosurgery. - : Journal of Neurosurgery Publishing Group (JNSPG). - 0022-3085. ; 90:1, s. 101-108
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Tidskriftsartikel (refereegranskat)abstract
- Object. The pathogenesis of cerebrospinal fluid (CSF) shunt infection is characterized by staphylococcal adhesion to the polymeric surface of the shunt catheter. Proteins from the CSF-fibronectin, vitronectin, and fibrinogen-are adsorbed to the surface of the catheter immediately after insertion. These proteins can interfere with the biological systems of the host and mediate staphylococcal adhesion to the surface of the catheter. In the present study, the presence of fibronectin, vitronectin, and fibrinogen on CSF shunts and temporary ventricular drainage catheters is shown. The presence of fragments of fibrinogen is also examined. Methods. The authors used the following methods: binding radiolabeled antibodies to the catheter surface, immunoblotting of catheter eluates, and scanning force microscopy of immunogold bound to the catheter surface. The immunoblot showed that vitronectin was adsorbed in its native form and that fibronectin was degraded into small fragments. Furthermore, the study demonstrated that the level of vitronectin in CSF increased in patients with an impaired CSF-blood barrier. To study complement activation, an antibody that recognizes the neoepitope of activated complement factor C9 was used. The presence of activated complement factor C9 was shown on both temporary catheters and shunts. Conclusions. Activation of complement close to the surface of an inserted catheter could contribute to the pathogenesis of CSF shunt infection.
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| 2. |
- Lundberg, F., et al.
(författare)
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Protein depositions on one hydrocephalus shunt and on fifteen temporary ventricular catheters
- 1997
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Ingår i: Acta Neurochirurgica. - 0001-6268. ; 139:8, s. 734-742
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Tidskriftsartikel (refereegranskat)abstract
- Biomaterials are commonly used in modern medicine. Proteins are adsorbed to the surface of the biomaterial immediately after insertion. This report demonstrates the presence of adsorbed proteins in one infected cerebrospinal shunt from a child with hydrocephalus and on fifteen temporary ventricular catheters from adult patients with spontaneous or traumatic brain injuries. Depositions of vitronectin, fibrinogen and thrombospondin-fibronectin to some extent - on the shunt surface was imaged by field-emission scanning electron microscopy. Vitronectin, fibronectin, fibrinogen, and thrombospondin on the ventricular catheters were shown with radio-actively labelled antibodies. Furthermore, protein adsorption from human cerebrospinal fluid to heparinized and unheparinized polymers was studied under flowing conditions in vitro. On heparinized polymer, significantly reduced levels of vitronectin, fibronectin, and thrombospondin were exposed, as measured after 4 hours in vitro perfusion. After 24 hours perfusion, the differences in protein exposition between heparinized and unheparinized polymers were substantially reduced.
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| 3. |
- Montelius, L., et al.
(författare)
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Novel all-silicon sensor structure with integrated poly-Si electrodes
- 1996
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Ingår i: ; , s. 2071-2072
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Konferensbidrag (refereegranskat)abstract
- The interest in miniaturization of modern chemical and medical sensors is steadily increasing. However, when employing methods and fabrication procedures especially developed for microelectronics, one may encounter new and unpredictable problems for applications in aqueous media. For instance, in microelectronics often a dual metal layer system is employed for making electrical contacts. In a solution such a contact may result in galvanic reactions and/or may dissolved in the cleaning agents used for sterilization of medical devices. To address such issues we have employed an all-silicon based process technology for fabrication of sturdy and reliable devices with integrated poly-Silicon electrodes that tolerate most chemical environments. In this presentation we will report on the first results using such electrodes. A comparative study between identical poly-Si and Aluminium electrodes was made in order to investigate the usefulness of poly-Si electrodes. We will also demonstrate the nice possibility to use well-documented methods for surface modifications using silane coupling chemistry. We believe this added benefit for the silicon based electrodes of easy surface modification processes, as compared with metal electrodes, to be extremely valuable for the development of accurate and tailored sensor structures for specific applications.
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