Radiation dose management systems-requirements and recommendations for users from the ESR EuroSafe Imaging initiative.

The European Directive 2013/59/Euratom requires member states of the European Union to ensure justification and optimisation of radiological procedures and store information on patient exposure for analysis and quality assurance. The EuroSafe Imaging campaign of the European Society of Radiology created a working group (WG) on "Dose Management" with the aim to provide European recommendations on the implementation of dose management systems (DMS) in clinical practice. The WG follows Action 4: "Promote dose management systems to establish local, national, and European diagnostic reference levels (DRL)" of the EuroSafe Imaging Call for Action 2018. DMS are designed for medical practitioners, radiographers, medical physics experts (MPE) and other health professionals involved in imaging to support their tasks and duties of radiation protection in accordance with local and national requirements. The WG analysed requirements and critical points when installing a DMS and classified the individual functions at different performance levels. KEY POINTS: • DMS are very helpful software tools for monitoring patient exposure, optimisation, compliance with DRLs and quality assurance. • DMS can help to fulfil dosimetric aspects of the European Directive 2013/59/Euratom. • The EuroSafe WG analyses DMS requirements and gives recommendations for users.

Harmonisation of imaging dosimetry in clinical practice: practical approaches and guidance from the ESR EuroSafe Imaging initiative.

The European Directive 2013/59/EURATOM requires member states of the European Union to ensure justification and optimisation of the radiological procedures and to include information on patient exposure as part of the report of the examinations. The EuroSafe Imaging campaign of the European Society of Radiology created a working group (WG) on "Dosimetry for imaging in clinical practice" with the aim to help with the dosimetry aspects required by European and national regulations. The primary focus topics were selected and a survey among the experts of the WG, allowed suggesting some initial consensus approaches.For information on patient exposure, it was agreed to include the dosimetric values reported by the imaging modalities (validated by a medical physics expert). It was also suggested to prepare educational material on dosimetric quantities for patients. Individual optimisation was considered a challenge, especially for interventional procedures. In these cases, patient and occupational doses should be part of the global optimisation process and trigger levels should be defined to avoid skin radiation injuries. Diagnostic Reference Levels (DRLs) always need to be considered for comparison with periodic patient dose audits. In the case of accidental or unintended exposures, a report should be produced for the Quality Assurance programme, together with an educational note to avoid the repetition of incidents. Dose registry and management systems should allow fulfilling the regulatory requirements of national and European regulations. In a second step, and after the initial experience with the Directive implementation, a wider survey will be considered.

An Aspergillus nidulans ß-mannanase with high transglycosylation capacity revealed through comparative studies within glycosidase family 5.

ß-Mannanases are involved in the conversion and modification of mannan-based saccharides. Using a retaining mechanism, they can, in addition to hydrolysis, also potentially perform transglycosylation reactions, synthesizing new glyco-conjugates. Transglycosylation has been reported for ß-mannanases in GH5 and GH113. However, although they share the same fold and catalytic mechanism, there may be differences in the enzymes' ability to perform transglycosylation. Three GH5 ß-mannanases from Aspergillus nidulans, AnMan5A, AnMan5B and AnMan5C, which belong to subfamily GH5_7 were studied. Comparative studies, including the GH5_7 TrMan5A from Trichoderma reesei, showed some differences between the enzymes. All the enzymes could perform transglycosylation but AnMan5B stood out in generating comparably higher amounts of transglycosylation products when incubated with manno-oligosaccharides. In addition, AnMan5B did not use alcohols as acceptor, which was also different compared to the other three ß-mannanases. In order to map the preferred binding of manno-oligosaccharides, incubations were performed in H2 (18)O. AnMan5B in contrary to the other enzymes did not generate any (18)O-labelled products. This further supported the idea that AnMan5B potentially prefers to use saccharides as acceptor instead of water. A homology model of AnMan5B showed a non-conserved Trp located in subsite +2, not present in the other studied enzymes. Strong aglycone binding seems to be important for transglycosylation with saccharides. Depending on the application, it is important to select the right enzyme.

Characteristics, formation, and pathophysiology of glucosepane: a major protein cross-link.

Advanced glycation end products are the results of a series of chemical reactions collectively known as the Maillard reaction, or nonenzymatic glycation, and sometimes cross-link proteins, thereby impairing their normal function. Glucosepane is the most abundant protein cross-link found in vivo so far and mainly has been shown to accumulate in the extracellular matrix, where it cross-links collagen. Levels of glucosepane increase with aging. By increasing collagen stiffness, glucosepane cross-links may have significant implications in several age-related diseases, such as cardiovascular disease, diabetes, and osteoporosis. Although the formation pathways for glucosepane are relatively well researched, much is still unknown about the accumulation and pathophysiology of glucosepane.