Effect of deprivation and gender on the incidence and management of acute brain disorders

OBJECTIVE: To determine the impact of deprivation and gender on the incidence and emergency management of acute brain disorders. DESIGN: Retrospective database review of mortality, hospital discharge, and ICU discharge data. SETTING: Lothian Health Board area, 1995-1999. PATIENTS AND PARTICIPANTS: All persons over the age of 15 dying or being discharged from hospital with a primary diagnosis of stroke, epilepsy, subarachnoid haemorrhage (SAH) or traumatic brain injury; patients registered in the Scottish Intensive Care Society Audit Database as having been discharged from the supraregional neurosciences intensive care unit with one of these as a primary diagnoses and a home postcode within the Lothian Health Board area. MEASUREMENTS AND RESULTS: Standardised ratios were calculated for hospital admission, mortality, and ICU admission by deprivation category and gender. Data were available for 29,205 hospital admissions, 5,227 deaths, and 360 ICU admissions. For all diagnoses, deprivation was associated with higher rates of hospital admission and death. Deprivation was associated with lower rates of ICU admission for traumatic brain injury and stroke. There was a U-shaped relationship between deprivation and ICU admission with epilepsy. There were no gender differences in rates of ICU admission. Males had higher rates of hospital admission for all conditions and of death from epilepsy and SAH, and lower rates of death from stroke. CONCLUSIONS: We have demonstrated deprivation- and gender- differences in the incidence and emergency management of four acute brain disorders. The identification of the source(s) of these differences is an important subject for further research.     

Should nurses be allowed to request X-rays in an accident & emergency department?

A prospective study was carried out during the month of November, 1990 in the A&E Department, St John's Hospital, Livingston in order to assess the extended role of the A&E nurse and their ability to request X-rays prior to patients being seen by a doctor. A total of 579 randomly selected patients were triaged by A&E Department nurses. Almost 3/4 of these patients were X-rayed at the request of the triage nurse. Less than 7% of these X-rays were considered to have been unnecessary by the doctor who subsequently managed the patient. Of those patients who had an X-ray after seeing a doctor, more than 90% fell within the X-ray triage criteria but had not had an X-ray requested by the triage nurse. Overall, nurses were shown to request X-rays correctly and efficiently with the result that patients had to spend less time in the A&E Department.     

Characterisation of transmission Raman spectroscopy for rapid quantitative analysis of intact multi-component pharmaceutical capsules

A detailed characterisation of the performance of transmission Raman spectroscopy was performed from the standpoint of rapid quantitative analysis of pharmaceutical capsules using production relevant formulations comprising of active pharmaceutical ingredient (API) and 3 common pharmaceutical excipients. This research builds on our earlier studies that identified the unique benefits of transmission Raman spectroscopy compared to conventional Raman spectroscopy. These include the ability to provide bulk information of the content of capsules, thus avoiding the sub-sampling problem, and the suppression of interference from the capsule shell. This study demonstrates, for the first time, the technique's insensitivity to the amount of material held within the capsules. Different capsules sizes with different overall fill weights (100–400 mg) and capsule shell colours were assayed with a single calibration model developed using only one weight and size sample set (100 mg) to a relative error of typically <3%. The relative root mean square error of prediction of the concentration of API for the main sample set (nominal content 75%, w/w) was 1.5% with a 5 s acquisition time. Models built using the same calibration set also predicted the 3 low level excipients with relative errors of 5–15%. The quantity of API was also predicted (with a relative error within ∼3%) using the same model for capsules prepared with different generations of API (i.e. API manufactured via different processes). The study provides further foundation blocks for the establishment of this emerging technique as a routine pharmaceutical analysis tool, capitalising on the inherently high chemical specificity of Raman spectroscopy and the non-invasive nature of the measurement. Ultimately, this technique has significant promise as a Process Analytical Technology (PAT) tool for online production application.     

Calcium-dependent phosphorylation regulates neuronal stability and plasticity in a highly precise pacemaker nucleus

Specific types of neurons show stable, predictable excitability properties, while other neurons show transient adaptive plasticity of their excitability. However, little attention has been paid to how the cellular pathways underlying adaptive plasticity interact with those that maintain neuronal stability. We addressed this question in the pacemaker neurons from a weakly electric fish because these neurons show a highly stable spontaneous firing rate as well as an N-methyl-D-aspartate (NMDA) receptor-dependent form of plasticity. We found that basal firing rates were regulated by a serial interaction of conventional and atypical PKC isoforms and that this interaction establishes individual differences within the species. We observed that NMDA receptor-dependent plasticity is achieved by further activation of these kinases. Importantly, the PKC pathway is maintained in an unsaturated baseline state to allow further Ca(2+)-dependent activation during plasticity. On the other hand, the Ca(2+)/calmodulin-dependent phosphatase calcineurin does not regulate baseline firing but is recruited to control the duration of the NMDA receptor-dependent plasticity and return the pacemaker firing rate back to baseline. This work illustrates how neuronal plasticity can be realized by biasing ongoing mechanisms of stability (e.g., PKC) and terminated by recruiting alternative mechanisms (e.g., calcineurin) that constrain excitability. We propose this as a general model for regulating activity-dependent change in neuronal excitability.     

Predicting the effect of muscle length on fatigue during electrical stimulation

Mathematical models have been developed to predict fatigue during functional electrical stimulation, but the predictive accuracy at different muscle lengths is unknown. The objectives of our study were to: (1) experimentally determine the relationship between knee extension angle (20°, 40°, 65°, and 90°) and fatigue of the quadriceps muscles, and (2) predict that relationship using a mathematical model. A computer‐controlled stimulator sent trains of pulses to surface electrodes on the thighs of five subjects while forces were measured at the ankle. A two‐component mathematical model was developed. One component accounted for force, and the other accounted for fatigue. The model was fit to the data, and parameters were identified at 90°. The fitted subject‐averaged r² value was 0.89. The model was used to predict fatigue at the remaining angles, and the subject‐averaged r² values were >0.75. Therefore, at least 75% of the variability in the measurements was explained by the model. The force model is explicitly dependent on angle, and the fatigue model is explicitly dependent on force; therefore, the dependence of fatigue on knee angle was implicit. Muscle Nerve, 2009