Letter from the editor.
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Journal Article↗
Biomedical subjects
R Von Versen
Publications and source records attributed to R Von Versen.
Demineralized Bone Matrix-stimulated Bone Regeneration in Rats Enhanced by an Angiogenic Dipeptide Derivate.
A lysyl-proline derivate (LP) known to stimulate angiogenesis and formation of granulation tissue was tested as a local additive to allogeneic demineralized bone matrix (DBM) using a rat craniotomy model. Peracetic-acid sterilized DBM (10 mg/defect) was implanted into three groups of 45 animals each with 0, 6 and 20 microg LP. Subsequent evaluation was done by descriptive histology, histomorphometry, and determination of the calcium content of the explants 7, 14, 28, 42 and 84 days post-implantation. Grafting with DBM alone resulted in defect bridging by newly formed bone with incorporated DBM residues on day 84. Addition of LP to the implants caused an enhanced capillarization on day 14 and 28 as well as an enhanced mineralization on day 14, 28, 42 and 84. Both effects were dose-dependent. These data suggest that the local application of a synthetic angiogenic factor significantly improve bone regeneration in DBM-grafted trephine defects in rats. Thereby, they reinforce the opinion that early angiogenesis is crucial for a number of subsequent events in the bone regeneration process.
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Comparison of the efficacy of virus inactivation methods in allogeneic avital bone tissue transplants.
Several procedures for inactivating viruses are used presently in the context of bone tissue transplants. Common methods used are gamma irradiation (25 kGy), treatment with moist heat (82.5 degrees C/15 min., lobator-sd2-system) as well as chemical sterilisation using peracetic acid-ethanol treatment (PES, 2% peracetic acid, 96% ethanol, Aqua [2:1:1], 200 mbar, agitation, 4 hours). Based on national and international guidelines, we tested the antivirucidal effectiveness of these methods in human bone transplants. Three enveloped viruses: human immunodeficiency virus type 2 (HIV-2), pseudorabies virus (PRV), bovine virus diarrhoea virus (BVDV), and three non-enveloped viruses were used: hepatitis A virus (HAV), poliovirus (PV-1), porcine/bovine parvovirus (PPV, BPV). Defatted spongiosa cuboids served as model in chemical treatment experiments, while cortical diaphyses were used in gamma irradiation experiments, and the effects of thermal treatment were tested in prepared femoral heads. The log(10) reduction was measured by cytopathogenic effects after virus titration (TCID(50)/mL). A dose of at least 33.9 kGy (bone model) at -30 +/- 5 degrees C was necessary to achieve a sufficient reduction (4 log(10) steps) of BPV, the most resistant one of all viruses investigated. Thermal treatment as well as PES treatment led to a reduction of virus titres by more than 4 log(10). Only HAV showed a reduction below 4 log(10) (2.87) with PES. After validation of the defatting step included for HAV-infected cells, a HAV-reduction of over 7 log(10) was found. All three sterilisation methods tested are recommended for bone transplant sterilisation, but only provided that additional safety measures (anamnestic informations, infectious serology, PCR in case of multiorgan donors) are taken.
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Quality issues in tissue banking: quality management systems - a review.
The situation in tissue banking changed radically and fundamentally at the beginning of the 1990s. The essential causes are on the one hand, the continually increasing demand for human cells and tissue and other biological material for clinical use and research, and on the other hand, the rapid progress in the medical, technical and natural sciences. Biotechnology in particular, has profited from this. Modern tissue banks could no longer be imagined without its methods.A consequence of these developments and a prerequisite for the fulfilment of the derived requirements is the necessity for national and international cooperation as well as the harmonisation of ethical principles and quality assurance standards and regulations (von Versen (1999) Ann Chir Gynaecol 88: 215-220). The introduction of an all-encompassing Quality Management System (QMS) is a suitable instrument for this purpose.After the presentation of explanations and definitions of quality terminology, this article describes the use of the international standard ISO 9000 as a general QMS, which embraces both the specific methodology as well as the general aspects of Quality Management (research and development, design control, education and training, documentation, traceability, management control, corrective action, etc.) in tissue banking. The individual elements of this system are explained and selected examples are described. The authors look upon this QMS as an indispensable instrument for harmonisation and international cooperation in tissue banking.Finally, the use of such a standard would be a positive sign to the regulatory authorities and the public that tissue banking is making a visible effort to introduce a world-class QMS in its operations.
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