A practical framework for data management processes and their evaluation in population-based medical registries.

Introduction: We present a framework for data management processes in population-based medical registries. Existing guidelines lack the concreteness we deem necessary for them to be of practical use, especially concerning the establishment of new registries. Therefore, we propose adjustments and concretisations with regard to data quality, data privacy, data security and registry purposes.

Active learning strategies for the deduplication of electronic patient data using classification trees.

Introduction: Supervised record linkage methods often require a clerical review to gain informative training data. Active learning means to actively prompt the user to label data with special characteristics in order to minimise the review costs. We conducted an empirical evaluation to investigate whether a simple active learning strategy using binary comparison patterns is sufficient or if string metrics together with a more sophisticated algorithm are necessary to achieve high accuracies with a small training set.

Missing values in deduplication of electronic patient data.

Introduction: Systematic approaches to dealing with missing values in record linkage are still lacking. This article compares the ad-hoc treatment of unknown comparison values as 'unequal' with other and more sophisticated approaches. An empirical evaluation was conducted of the methods on real-world data as well as on simulated data based on them.

Controlling false match rates in record linkage using extreme value theory.

Cleansing data from synonyms and homonyms is a relevant task in fields where high quality of data is crucial, for example in disease registries and medical research networks. Record linkage provides methods for minimizing synonym and homonym errors thereby improving data quality. We focus our attention to the case of homonym errors (in the following denoted as 'false matches'), in which records belonging to different entities are wrongly classified as equal.

A data protection scheme for medical research networks. Review after five years of operation.

Background: The data protection requirements matured in parallel to new clinical tests generating more personal data since the 1960s. About ten years ago it was recognized that a generic data protection scheme for medical research networks is required, which reinforces patient rights but also allows economically feasible medical research compared to "hand-carved" individual solutions.

Objectives: To give recommendations for more efficient IT infrastructures for medical research networks in compliance with data protection requirements.

Evaluation of record linkage methods for iterative insertions.

Objectives: There have been many developments and applications of mathematical methods in the context of record linkage as one area of interdisciplinary research efforts. However, comparative evaluations of record linkage methods are still underrepresented. In this paper improvements of the Fellegi-Sunter model are compared with other elaborated classification methods in order to direct further research endeavors to the most promising methodologies.

[Registries for rare diseases. Compliance and data protection].

For rare diseases, clinical and epidemiological research suffers from very small numbers of cases. A comprehensive collection of data and information in registries is an essential precondition to improve this situation. To this end, a number of disease specific networks have started collecting data with support from the German Ministry of Research.

Integrated information systems for translational medicine.

Objectives: Translational medicine research needs a two-way information highway between 'bedside' and 'bench'. Unfortunately there are still weak links between successfully integrated information roads for bench, i.e.

An optimal code for patient identifiers.

How to distinguish 1 billion individuals by an identifier consisting of eight characters, allowing a reasonable amount of error detection or even error correction? Our solution of this problem is an optimal code over a 32-character alphabet that detects up to two errors and corrects one error as well as a transposition of two adjacent characters. The corresponding encoding and error checking algorithms are available for free; they are also embedded as components of the pseudonymisation service that is used in the TMF-the German telematics platform for health research networks.

Secondary use of the EHR via pseudonymisation.

The Electronic Health Record (EHR) has many secondary uses, such as health economy and health care research, or disease specific clinical or epidemiological research. For these uses in general the patient identity is not needed, therefore the data must be anonymised or pseudonymised. Whereas for one-time use of the data this procedure is straightforward, long-term data accumulation or the necessity of re-identification require a more sophisticated approach.

[IT safety in medical networks--current problems and approach to solutions].

Designers and users of medical networks have to face strong requirements for data protection and security. Professional discretion and data protection laws allow the transfer of or access to patient data only in a therapeutic context. These data should also be protected from the network provider.

[Clinical data protection and the internet].

The benefit of using the internet in health care is growing: Information retrieval, communication, and telemedical cooperation support the physician and serve the patient. On the other hand connecting a hospital to the internet leads to considerable security problems, exposes sensible data to danger, and corrupts the professional discretion, unless the connection is installed and managed with extreme care. The state of the art for an internet connection is a firewall system.

Retention of hyaluronic acid in alginate beads: aspects for in vitro cartilage engineering.

Alginate has been used successfully for three-dimensional chondrocyte cultures and may be important for cartilage transplant formation. However, alginate is not a natural component of the cartilage matrix. The aim of this study was (a) to supplement alginate with the extracellular matrix component hyaluronic acid; and (b) to analyze the hyaluronic acid retention in different alginate gels.

THEMPO: a knowledge-based system for therapy planning in pediatric oncology.

This article describes the knowledge-based system THEMPO (Therapy Management in Pediatric Oncology), which supports protocol-directed therapy planning and configuration in pediatric oncology. THEMPO provides a semantic network controlled by graph grammars to cover the different types of knowledge relevant in the domain, and offers a suite of acquisition tools for knowledge base authoring. Medical problem solvers, operating on the oncological network, reason about adequate therapeutic and diagnostic timetables for a patient.

[Data protection measures in medical information systems].

Information technology and networks should improve health care in the next few years. But the information systems in use are open systems; processing and transporting data by them is incompatible with the high privacy requirements of patient information. We have the technical means to achieve better security, but we cannot build them into existing systems by way of addition--the suppliers of hard- and software must integrate them into the systems, beginning with the system design, in a way that doesn't detract users from their proper tasks; users shouldn't have to do more than log into the IT system with their Health Professional Card.

A graph-grammar approach to represent causal, temporal and other contexts in an oncological patient record.

The data of a patient undergoing complex diagnostic and therapeutic procedures do not only form a simple chronology of events, but are closely related in many ways. Such data contexts include causal or temporal relationships, they express inconsistencies and revision processes, or describe patient-specific heuristics. The knowledge of data contexts supports the retrospective understanding of the medical decision-making process and is a valuable base for further treatment.

Pseudonyms for cancer registries.

In order to conform to the rigid German legislation on data privacy and security we developed a new concept of data flow and data storage for population-based cancer registries. A special trusted office generates a pseudonym for each case by a cryptographic procedure. This office also handles the notification of cases and communicates with the reporting physicians.

A new concept to ensure data privacy and data security in cancer registries.

In order to conform to the rigid German legislation on data privacy and security, a new concept of data flow and data storage for population-based cancer registries has been developed. This paper describes the basic principles of this approach and presents results from a pilot study in Rheinland-Pfalz. The cancer registry consists of two offices.

Bead cellulose derivatives as supports for immobilization and chromatographic purification of proteins.

Characteristic data are presented for Divicell, a macroporous bead cellulose with excellent flow parameters. The preparation of Divicell derivatives and their properties are described with respect to their application as chromatographic supports. The ion exchangers Divicell DEAE and Divicell CM were manufactured in two types with different exclusion limits and an available capacity for proteins of up to 100 mg/ml gel.

Modification of carboxyl groups on NADPH-cytochrome P-450 reductase involved in binding of cytochromes c and P-450 LM2.

Carboxyl groups of NADPH-cytochrome P-450 reductase have been modified with the water-soluble carbodiimide EDC. Although there is no significant loss in DCPIP reduction the activity with cytochrome c and cytochrome P-450 LM2 as electron acceptors was inhibited by about 60 and 85%, respectively (1 h incubation time, 20 mM EDC). The inactivation by EDC was nearly completely prevented in the presence of cytochrome P-450 LM2, but not by bovine serum albumin.

p-Nitrophenetole deethylase activity of rat liver microsomes entrapped in polyelectrolyte capsules.

Liver microsomes from phenobarbital induced rats are entrapped in capsules prepared from polyelectrolytes. A comparative analysis of the deethylase activity against p-nitrophenetole by encapsulated and freely suspended microsomes is carried out. The pH optimum occurs at about 7.

Spin state control of cytochrome P-450 reduction and catalytic activity in a reconstituted P-450 LM2 system as induced by a series of benzphetamine analogues.

Reconstituted liposomal cytochrome P-450 LM2 was reacted with a series of benzphetamine analogues as substrates. Based on the thermodynamical model of Ristau et al. (Biochim.

[Activity of urease in microcapsules].

The activity of urease in microcapsules formed by a symplex membrane from cellulose sulphate and polydimethyldiallyl ammonium chloride is studied and compared with that of free urease in solution. Both free and encapsulated urease exhibits a similar pH optimum. The interaction of urease with cellulose sulphate causes a decrease of the activity down to 35 to 38%.

[Immobilization of proteins and cell fragments using a new method of microencapsulation].

Cytochrome c, hemoglobin, urease and liver microsomes were microencapsulated in aqueous solution by use of a new method. The membrane of the microcapsules consist of a symplex, which is formed predominantly by electrostatic interactions between a polymeric polyanion and a polymeric polycation. The membrane is characterized by high mechanical stability and is a barrier for globular substances with molecular weights larger than 12000, but permeable for substances with lower molecular weight.

[The interaction of methemoglobin and modified poly-(hydroxyethylmethacrylates) studied by spectroscopic methods].

The interaction between methemoglobin (MetHb) and macroporous matrices on the basis of polymethacrylates was investigated by means of optical and e.p.r.