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Denis Murphy

Publications and source records attributed to Denis Murphy.

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Risk assessment as collective clinical judgement.

INTRODUCTION: Risk assessment occupies an increasingly important position in psychiatry. This paper contends that collective judgement is the optimal method of assessing risk. THE MEANING OF RISK: Risk has a dual meaning: emotional and judgemental. RISKS FACED BY STAFF: Assaults, threats and survival anxiety. THE EFFECTS OF DANGER ON THE GROUP: Staff wariness and resistance, attribution of blame. THE AMBIGUOUS TASK: For a group to function well it must have a clear task. Custodial roles can lead to ambiguity. THE EMOTIONS OF LARGER GROUPS: Externally directed hostility, internal homogenization of views. SOCIAL DEFENCES: Rituals can develop in forensic institutions, as well as militarism. ANTI-THERAPEUTIC CULTURE: Sadism may develop where a marked power differential develops. THE ROLE OF THE LEADER: Danger intensifies the feelings about leaders, perhaps idealization, perhaps disaffection. Leaders and others need to agree on risk assessment or fragmentation will occur. THE MODIFICATION OF RISK: The assessment of risk may modify it. Mutual hostility must be reduced. Dialogue and understanding are needed. A CLIMATE FOR RISK ASSESSMENT: The environment should be less authoritarian and more democratic, so that patients can join a group and internalize its values. Reflective space is also required. CONCLUSIONS: Risk assessment is best described in terms of human endeavour, not in the language of scientific measurement.

Adult↗

A peptide methionine sulfoxide reductase highly expressed in photosynthetic tissue in Arabidopsis thaliana can protect the chaperone-like activity of a chloroplast-localized small heat shock protein.

The oxidation of methionine residues in proteins to methionine sulfoxides occurs frequently and protein repair by reduction of the methionine sulfoxides is mediated by an enzyme, peptide methionine sulfoxide reductase (PMSR, EC 1.8.4.6), universally present in the genomes of all so far sequenced organisms. Recently, five PMSR-like genes were identified in Arabidopsis thaliana, including one plastidic isoform, chloroplast localised plastidial peptide methionine sulfoxide reductase (pPMSR) that was chloroplast-localized and highly expressed in actively photosynthesizing tissue (Sadanandom A et al., 2000). However, no endogenous substrate to the pPMSR was identified. Here we report that a set of highly conserved methionine residues in Hsp21, a chloroplast-localized small heat shock protein, can become sulfoxidized and thereafter reduced back to methionines by this pPMSR. The pPMSR activity was evaluated using recombinantly expressed pPMSR and Hsp21 from Arabidopsis thaliana and a direct detection of methionine sulfoxides in Hsp21 by mass spectrometry. The pPMSR-catalyzed reduction of Hsp21 methionine sulfoxides occurred on a minute time-scale, was ultimately DTT-dependent and led to recovery of Hsp21 conformation and chaperone-like activity, both of which are lost upon methionine sulfoxidation (Härndahl et al., 2001). These data indicate that one important function of pPMSR may be to prevent inactivation of Hsp21 by methionine sulfoxidation, since small heat shock proteins are crucial for cellular resistance to oxidative stress.

Arabidopsis↗