Biomedical subjects

R L Deijkers

Publications and source records attributed to R L Deijkers.

4 recordsLinked to original sources

PubMed1999

A comparative study of blood and bone marrow cultures in cadaveric bone donation.

The results of blood cultures taken from cadaveric bone donors were compared with bone marrow and also swab cultures of the procured grafts. In eight of the 95 donors evaluated, pathogenic micro-organisms were detected in the blood sample. In two, identical micro-organisms were cultured from the blood and bone marrow sample whilst the swab cultures were negative. Considering the low sensitivity of the swab culture, the organisms detected in the blood culture were likely to have spread haematogenously and considered to be present in the explanted grafts. Bacteriological screening of bone donors is extremely important since the transmission of micro-organisms via an allograft can lead to serious complications in the recipient. Positive blood cultures provide important information on the presence of pathogenic micro-organisms in grafts obtained from cadaveric bone donors and are therefore essential in deciding whether a graft is bacteriologically acceptable for transplantation.

Blood↗

PubMed1999

Human bone allografts can induce T cells with high affinity for donor antigens.

We analysed the cellular immune response in ten transplantations of different massive bone allografts, of which five had a poor clinical outcome. Cytotoxic T lymphocytes (CTL) and T helper lymphocytes (TH) against mismatched donor antigens were found in all patients. More importantly, CTL with a high affinity for donor antigens were found in five cases. High-affinity CTL need no CD8 molecule to stabilise the antigen binding and are strongly associated with rejection of heart and corneal transplants. Even after removal of most of the bone-marrow cells, we found high-affinity CTL and high TH frequencies. This T-cell response could be detected over a period of years. We conclude that frozen bone allografts can induce high-affinity donor-specific CTL. The present assay allows qualification and quantification of the levels of CTL and TH in the blood. This approach may be helpful in studying the effect of the immune response on the outcome of the graft.

Adolescent↗

PubMed1997

Contamination of bone allografts: analysis of incidence and predisposing factors.

We analysed the bacterial contamination of 1999 bone allografts retrieved from 200 cadaver donors under sterile operating conditions. The effect of various factors on the relative risk of contamination was estimated using a multiple logistic regression model. Organisms of low pathogenicity were cultured from 50% of the grafts and of high pathogenicity from 3%. The risk of contamination with low pathogenic organisms (mainly skin commensals) increased by a factor of 1.6 for each member added to the procurement team. The risk of contamination with high pathogenic organisms (mainly contaminants from the gastrointestinal tract) was 3.4 times higher in donors with a traumatic cause of death and 5.2 times higher in those with a positive blood culture. Preceding organ procurement did not significantly influence the risk of contamination. Rinsing the graft with an antibiotic solution was not an effective decontamination method. The major source of contamination is exogenous and is strongly influenced by the procurement team. Contamination from endogenous sources can be controlled by donor selection. We discuss methods that can be used to decrease contamination and the rate of discarding of bone allografts.

Anti-Bacterial Agents↗

PubMed1995

[5-year experience with a central bone bank].

Since December 1988 the Leiden Bone Bank Foundation, in cooperation with the BIS Foundation, makes allogeneic bone and related soft tissue available for transplantation. Bone banking has become a scientifically high level medical activity in which international standards are established in order to provide safe and effective allografts. Careful donor selection and extensive laboratory testing are the cornerstones for the prevention of disease transmission. In the first 5 years of the existence of the Leiden Bone Bank 450 deep frozen massive bone allografts, of which 221 osteoarticular and intercalary allografts, were shipped to different clinics inside and outside the Netherlands. Furthermore, 322 deep frozen soft tissues, 1877 units of freeze dried bone grafts and 5629 units of demineralized grafts were distributed. The number of transplants with allogeneic bone and related soft tissue from the Leiden Bone Bank increased each year by at least 30% Bone and related soft tissue allografts were used in orthopaedic surgery, neurosurgery and maxillofacial surgery. There are no known cases of transmission of infectious diseases by grafts distributed by the Leiden Bone Bank.

Bone Transplantation↗