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Biomedical subjects

R Hallam

Publications and source records attributed to R Hallam.

6 recordsLinked to original sources
PubMed2001

Interaction of the influenza virus nucleoprotein with the cellular CRM1-mediated nuclear export pathway.

Influenza virus transcription occurs in the nuclei of infected cells, where the viral genomic RNAs are complexed with a nucleoprotein (NP) to form ribonucleoprotein (RNP) structures. Prior to assembly into progeny virions, these RNPs exit the nucleus and accumulate in the cytoplasm. The mechanisms responsible for RNP export are only partially understood but have been proposed to involve the viral M1 and NS2 polypeptides. We found that the drug leptomycin B (LMB), which specifically inactivates the cellular CRM1 polypeptide, caused nuclear retention of NP in virus-infected cells, indicating a role for the CRM1 nuclear export pathway in RNP egress. However, no alteration was seen in the cellular distribution of M1 or NS2, even in the case of a mutant virus which synthesizes greatly reduced amounts of NS2. Furthermore, NP was distributed throughout the nuclei of infected cells at early times postinfection but, when retained in the nucleus at late times by LMB treatment, was redistributed to the periphery of the nucleoplasm. No such change was seen in the nuclear distribution of M1 or NS2 after drug treatment. Similar to the behavior of NP, M1 and NS2 in infected cells, LMB treatment of cells expressing each polypeptide in isolation caused nuclear retention of NP but not M1 or NS2. Conversely, overexpression of CRM1 caused increased cytoplasmic accumulation of NP but had little effect on M1 or NS2 distribution. Consistent with this, NP bound CRM1 in vitro. Overall, these data raise the possibility that RNP export is mediated by a direct interaction between NP and the cellular CRM1 export pathway.

Animals↗
PubMed1988

Dizziness: behavioural, subjective and organic aspects.

The aim of the study was to investigate the relationship between medical and behavioural aspects of dizziness, and the subjective experiences before, during and after an 'attack'. Clinical and self-report data were collected on 60 patients who attended a neuro-otology clinic and whose main complaint was dizziness. The results indicated little direct correlation between subjective experience and organic severity, though there was some correlation between types of movement provocation and both subjective and organic factors. Correspondence analysis of self-reported dizzy sensations revealed four principal clusters. There was a clear distinction between attacks characterized by sensations of actual loss of balance and those preceded by autonomic sensations. Two types of mainly psychologically generated dizziness were proposed: one characterized by inhibition of sensory-motor processes and breathing problems; the other by a range of sympathetic signs. It is suggested that the reporting of sensations should be considered as an independent part of dizziness behaviour and not as a by-product of the physiological disturbance.

Adolescent↗
PubMed1983

An experimental analysis of fearlessness and courage.

In an attempt to assess the performance under stress of people who had received awards for gallantry, the subjective, behavioural and psychophysiological reactions of a group of seven decorated bomb-disposal operators were measured during a conflict test. Compared to a group of seven equally experienced and successful, but non-decorated, bomb-disposal operators, the decorated subjects maintained a lower cardiac rate when making difficult discriminations under threat of shock. There were no differences between the groups on subjective reactivity or on their performance under stress. Both groups of bomb-disposal operators reported having experienced fewer fearful reactions than did a small number of comparison subjects. The implications of the results for theories of fear and of courage are considered.

Adult↗