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Biomedical subjects

A Ehrenberg

Publications and source records attributed to A Ehrenberg.

120 records · Page 7Linked to original sources
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Free radical transfer, fluctuating structure and reaction cycle of ribonucleotide reductase.

Our understanding of the nature and functional importance of protein dynamics is based on experimental and theoretical work on rather 'simple' systems. Here, the principles of the fluctuating structure of a protein is applied to the complex enzyme ribonucleotide reductase (RNR). This enzyme contains a stable tyrosyl radical, which is a strong oxidant. The radical initiates the enzymatic reaction by oxidizing the ribose moeity of the substrate, bound at a distance of ca. 35 A away from the tyrosine harboring the radical. The transfer of the oxidation equivalent, the electron hole, requires a chain of overlapping electronic orbitals along the route, and is made energetically possible by the simultaneous switching of a series of H-bonds, making the transfer charge neutral. Only a fraction of the enormous number of accessible protein substates support this transfer. The probability of an enzyme molecule to obtain such a substate by thermal fluctuations is negligible, except for the case of a complete enzyme with bound substrate. When the radical has been transferred to the ribose, its 2'-OH is immediately reduced to 2'-H by the enzyme, and the electron hole goes back via the chains of orbital overlaps and H-bonds. This model is capable to explain all known kinetic properties of the wild type enzyme and its mutated forms. The analogy between this model of how the fluctuating protein structure controls and makes the radical transfer possible in RNR and recent ideas about the mechanism of the anomalously fast proton conduction in liquid water is considered.

Free Radicals↗
PubMedDate not supplied

Patient problems, needs, and nursing diagnoses in Swedish nursing home records.

PURPOSE: To describe the main problems, needs, risks, and nursing diagnoses and to examine the descriptions of some common and serious patient problems in nursing home records. METHODS: A retrospective audit of a stratified, random sample (N = 12O) of patient records from eight nursing homes in six Swedish municipalities. FINDINGS: Results showed major deficiencies in nursing documentation in the patient records. Only one record contained a comprehensive description of one patient problem that corresponded to the requirements of Swedish laws and regulations. No record was found that contained a systematic and comprehensive assessment of any of the selected problems based on established criteria or the use of an assessment instrument. CONCLUSIONS: Nursing documentation in patient records does not reflect the use of systematic assessment and research-based instruments for determining patient care needs. Nurses need skills in assessment in the care of the elderly to be able to set priorities in care and deliver adequate care.

Humans↗
PubMedDate not supplied

Towards basic nursing information in patient records.

Four key concepts for good nursing care and a list of key words for nursing documentation in patient records were established and to some extent tried in clinical practice in Sweden. The method consisted of the following steps: extensive literature review, review of nursing records, development of a list of key words on two levels, a first level corresponding to the nursing process, and a second level consisting of subdivisions for possible use in practice, use and assessment in clinical practice by nurses and students, expert panel judgement and refinement of the key words including an examination of semantic accuracy of the Swedish key words by an expert in Nordic languages. The proposed key words are presented both in English and Swedish and explanations, comments and references are given. The version of key words presented here is subject to further testing for possible modifications.

Documentation↗