[Procedural guidelines. Good tissue practice for cornea banks]. / Arbeitsrichtlinien. Gute Fachliche Praxis für Hornhautbanken.

A cornea bank must have an organizational structure in which responsibility and authority to issue directives are clearly defined. It must also use a documented quality management system on the basis of good practice procedures which is maintained to the current standards. The personnel of a cornea bank must be present in sufficient numbers and be suitably qualified. A cornea bank must be in possession of appropriate facilities which are suitable for the main purpose of conservation of donor corneas. All equipment must be designed and maintained corresponding to the intended purpose. Deviations from the stipulated quality and safety standards must give rise to documented investigations which include decisions on options for correctional and preventive measures. Acquisition of donors and tissue sampling must be strictly controlled and documented. This also applies to entry of donor tissue in the cornea bank. During conservation a microscopic examination of the endothelial cell layer must be carried out at least once. Measures must be taken to keep the risk of contamination as low as possible. Donor corneal tissue can only be released if defined criteria are fulfilled. Any suspicion of severe undesired reactions and events for the recipient of a corneal transplant must be registered with the authorities. The activities of a cornea bank must maintain and adapt the state-of-the-art with respect to scientific progress.

Evolution of a group of transposed human V kappa genes.

Eleven V kappa genes within a genomic region which has been transposed from the short to the long arm of chromosome 2 have been characterized by sequence analyses. Nine of the analysed genes exist within the genome in three highly homologous copies each. Sequence comparisons of the triplicated genes make it very likely that the three copies of a given gene were produced at different times during evolution. A chain of events which led to a stepwise amplification of precursor genes is discussed.