Co-treatment with riluzole and GDNF is necessary for functional recovery after ventral root avulsion injury

Unilateral avulsion of lumbar ventral roots kills approximately 50% of injured motoneurons within 2 weeks of surgery. Immediate treatment involving surgical reimplantation of the ventral root (VRI) or intrathecal glial cell line-derived neurotrophic factor (GDNF) delivery or intraperitoneal injection of riluzole for 2 weeks ameliorates motoneuron death to 80% of control but combining the different treatment paradigms did not further enhance survival except when GDNF was combined with VRI. At 3 months, all combined treatments provided a neuroprotective effect compared to avulsion only, but the neuroprotective effect of surgical reimplantation alone was not maintained unless combined with riluzole and GDNF treatment. Analysis of regenerating motoneurons using retrograde labelling techniques showed that riluzole, but not GDNF, increased the number of dendrites per labelled motoneuron. However, when functional motor recovery was assessed using the BBB locomotor score and rotarod tests, only VRI animals treated with riluzole and GDNF application showed significantly improved locomotor function in both tests. Our results show that functional recovery appears related to a combination of enhanced dendrite formation, increased motoneuron survival and the neurotrophic actions of GDNF. Thus, combination treatment may offer a new therapeutic strategy for treating patients with avulsion injury.     

Effects of modafinil on cognitive and meta-cognitive performance

The stimulant modafinil has proved to be an effective treatment modality for narcolepsy and related sleep disorders and is also being studied for use during sustained military operations to ameliorate the effects of fatigue due to sleep loss. However, a previous study reported that a relatively large, single dose of modafinil (300 mg), administered to already sleep-deprived individuals, caused participants to overestimate their cognitive abilities (i.e. 'overconfidence'). Because the predominant application of modafinil is in otherwise healthy, non-sleep-deprived individuals, the present study investigated the generality of modafinil-induced overconfidence in a group of 18 healthy, non sleep-deprived adults. The design involved a double-blind, placebo controlled, fully within-subjects manipulation of placebo and modafinil (4 mg/kg: approximately 300 mg, on average) over three 50-min cognitive testing sessions (i.e. before drug ingestion, and at 90 and 180 min after drug ingestion). The cognitive task battery included subjective assessments of mood, fatigue, affect, vigor and motivation, and cognitive assessments of serial reaction time, logical reasoning, visual comparison, mental addition and vigilance. In addition, trial-by-trial confidence judgements were obtained for two of the cognitive tasks and more global, task level assessments of performance were obtained for four of the cognitive tasks. Relative to placebo, modafinil improved fatigue levels, motivation, reaction time and vigilance. In terms of self-assessments of cognitive performance, both the placebo and modafinil conditions were 'well calibrated' on trial-by-trial confidence judgements, showing neither marked over- nor under-confidence. Of note, the modafinil condition displayed a non-significant tendency towards 'overconfidence' for task-level assessments of performance. The present findings highlight the need for continued research on the many complex interactions involving fatigue states, occasional versus long-term stimulant use, and subjective assessments of fatigue and cognitive performance.     

The human perspective on health care reform: coping with diabetes in Kyrgyzstan

Health systems world wide are confronted by the challenge of rising levels of chronic diseases. Yet existing approaches to health system analysis often fail to capture the complexity of the responses required to address this challenge. In this paper we describe the results of a pilot study using a rapid appraisal technique to assess the performance of the health care system in Kyrgyzstan, a former Soviet central Asian republic. The study focuses on diabetes, a condition whose effective management requires a coordinated response involving many components of the health care system. The study sets out a conceptual framework in which the system is seen from the perspectives of users, health professionals and policy-makers. It sees the effective delivery of health care as dependent on appropriate investment in human, physical, intellectual and social resources. The study reveals important weaknesses in all of these areas, although it also notes that current policies, while constrained by the legacy of the past and by limited resources, are beginning to tackle them. This pilot study indicates that rapid appraisal, using a condition such as diabetes, where those affected can be easily identified, offers a means of gaining important insights into a health care system.     

Anatomy of Complications workshop: an educational strategy to improve performance in obstetricians and gynaecologists

Many specialist obstetricians and gynaecologists feel inadequately trained to deal with certain situations such as injury to bowel, bladder, ureter and major vessels, and value further training to prevent and manage these problems. We present the structure, objectives and rationale for a surgical skills workshop, which is an intensive practical learning experience aimed to improve the performance of obstetricians and gynaecologists. The overall objective of the workshop is improvement in the prevention and management of complications in obstetric and gynaecological surgery. Over 100 participants have completed the workshop so far. Pre-workshop preparation includes anatomical illustrations to guide reading and a training video describing surgical skills, ewe anatomy and hysterectomy in the ewe. There are four modules: anatomy includes an interactive lecture, cadaveric dissection and examination of prosections with specific learning tasks. Surgical skills involves the demonstration, practice and learning of techniques needed to deal with unexpected operative injury to bowel, bladder, ureter and major blood vessels. Live animal surgery on a ewe allows further supervised practice of the previously learned skills plus the repair of serious vascular injury. Case presentations allow each participant to present a complicated case in a facilitated group session with discussion and feedback from their peers. This session is controlled, non-threatening and a valuable interactive learning experience. Participant feedback suggests that this workshop format is useful and appears to improve the confidence, competence and performance of the participants. This workshop is presented as a template on which other educational activities can be developed.     

Temporal precision of interceptive action: differential effects of target size and speed

The duration of movements made to intercept moving targets decreases and movement speed increases when interception requires greater temporal precision. Changes in target size and target speed can have the same effect on required temporal precision, but the response to these changes differs: changes in target speed elicit larger changes in response speed. A possible explanation is that people attempt to strike the target in a central zone that does not vary much with variation in physical target size: the "effective size" of the target is relatively constant over changes in physical size. Three experiments are reported that test this idea. Participants performed two tasks: (1) strike a moving target with a bat moved perpendicular to the path of the target; (2) press on a force transducer when the target was in a location where it could be struck by the bat. Target speed was varied and target size held constant in experiment 1. Target speed and size were co-varied in experiment 2, keeping the required temporal precision constant. Target size was varied and target speed held constant in experiment 3 to give the same temporal precision as experiment 1. Duration of hitting movements decreased and maximum movement speed increased with increases in target speed and/or temporal precision requirements in all experiments. The effects were largest in experiment 1 and smallest in experiment 3. Analysis of a measure of effective target size (standard deviation of strike locations on the target) failed to support the hypothesis that performance differences could be explained in terms of effective size rather than actual physical size. In the pressing task, participants produced greater peak forces and shorter force pulses when the temporal precision required was greater, showing that the response to increasing temporal precision generalizes to different responses. It is concluded that target size and target speed have independent effects on performance. Electronic Publication     

Masticatory performance in patients with myasthenia gravis

Masticatory muscle electromyograms (EMGs) were recorded while patients with bulbar myasthenia gravis chewed artificial food and compared with those of patients with ocular myasthenia gravis, patients in clinical remission who had previously suffered from bulbar myasthenia gravis and healthy individuals. Masticatory performance and EMGs were significantly smaller in the bulbar group. There were no indications of subclinical masticatory muscle weakness in patients with bulbar myasthenia gravis in remission and in patients with ocular myasthenia gravis. Patients with bulbar myasthenia gravis barely compensated for muscular weakness by chewing at a higher percentage of their maximal EMG. These quantitative findings, when combined with subjective reports of masticatory muscle weakness, show that a need to support the jaw is characteristic of patients with bulbar myasthenia gravis who produce low EMG activity.     

Insomnia,metabolic rate and sleep restoration

Studies have shown occasional evidence of increased physiological activity in patients with primary insomnia. We hypothesized that metabolic rate, as measured by overall oxygen use (VO2), might be a more general index of increased physiological activity. An initial experiment found elevated VO2 both at night and during the day in patients with primary insomnia as compared with matched normal sleepers. A second experiment found significant but more modest increases in VO2 in patients with Sleep State Misperception Insomnia [who complain of poor sleep but who had normal sleep by electroencephalographic (EEG) criteria]. In a third experiment, normal young adults were given caffeine 400 mg three times per day (TID) for 1 week as a means of increasing VO2 and possibly producing other symptoms of insomnia. Participants developed many symptoms consistent with those seen in patients with primary insomnia (poor sleep, increased latency on the Multiple Sleep Latency Test, increasing fatigue despite physiological activation, and increased anxiety on the Minnesota Multiphasic Personality Inventory (MMPI)). In a final experiment, physiological arousal was again produced by caffeine to determine if sleep with elevated arousal would be less restorative. All subjects (Ss) slept for 3.5 h after being given 400 mg of caffeine. During 41 h of sleep deprivation that followed, there was no significant condition difference for the Multiple Sleep Latency Test or mood measures. The results provided only weak support for the idea that sleep is less restorative after physiological arousal.     

Differences in physical performance between men and women with and without lymphoma

OBJECTIVES: To describe and compare physical performance profiles in men and women with lymphoma with age- and gender-matched controls and to examine relationships among fatigue severity and physical performance in men and women with lymphoma. DESIGN: Case-control study. SETTING: Outpatient lymphoma service in a major cancer teaching hospital. PARTICIPANTS: Fifty-one patients with lymphoma (26 women, 25 men), age- and gender-matched to 51 subjects without lymphoma. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A physical performance test battery consisting of a 50-ft (15-m) walk, a 6-minute walk, forward reach, repeated sit-to-stand, repeated reach-up, timed belt tie, sock test, and coin test. Patients also completed the Brief Fatigue Inventory (BFI). RESULTS: Multivariate analysis of variance was significant for main effects of group (F(8,89)=27.12, P<.05) and gender (F(8,89)=3.09, P<.05), and there was no significant interaction. Subsequent analyses found significant differences between groups and gender in the repeated reach-up task, forward reach, 50-ft walk, and distance walked in 6 minutes. Correlations among physical performance tasks and total BFI interference scores were moderate (r range,.27-.43; P<.05) for tasks involving upper extremity, and stronger (r range,.51 to -.73; P<.05) for tasks that involved whole-body movements. CONCLUSION: There is a leveling effect of lymphoma across gender on most tasks. The significant relations between physical performance tasks and fatigue are suggestive of the pervasive influence of fatigue on physical function.     

The impact of a nap opportunity during the night shift on the performance and alertness of 12-h shift workers

The purpose of this workplace evaluation was to assess the effects on performance, alertness and subsequent sleep of strategic napping on 12-h overnight shifts. In a counterbalanced crossover design, 24 male aircraft maintenance engineers working in a forward rotating 12-h shift pattern volunteered to take part in the study for two work weeks. During the experimental week, each subject was given the opportunity to take a 20-min nap at work between 01:00 and 03:00 h on each of their two overnight shifts. On the control week no naps were taken on the night shifts. A computerized neurobehavioural test battery was employed to assess performance and subjective levels of fatigue at the beginning and end of each night shift, and pre- and postnap. Subjects were also asked to rate how near they had come to falling asleep while driving to and from work. The results revealed that taking a single 20-min nap during the first night shift significantly improved speed of response on a vigilance task measured at the end of the shift compared with the control condition. On the second night shift there was no effect of the nap on performance. Taking a short nap during either night shift had no significant effect on subjective ratings of fatigue, the level of sleepiness reported while driving to and from work, or subsequent sleep duration and sleep quality. Overall the results suggest some promise for a short duration nap taken in the workplace to counteract performance deficits associated with the first night shift.     

A path model of factors influencing the academic performance of nursing students

AIMS: The aim of this study was to build and test a model describing some of the psychological processes underlying nursing students' academic performance. The model hypothesized that age and entry qualifications influence students' academic motivation (locus of control, academic worries, self-efficacy, and expectations), and that this in turn affects their decisions to seek support, which subsequently influences their academic performance. RATIONALE AND BACKGROUND: A literature search showed that previous academic motivation research is piecemeal. The present work sought to integrate previous findings into a coherent framework as a way of advancing our understanding of the complex interactive nature of the factors influencing student performance. METHOD: Path analysis was performed on data obtained from questionnaires and university records for 315 students undertaking a preregistration diploma course in nursing at a university in the Northwest of England. RESULTS: Support-seeking was more predictive of student performance than entry qualifications. Support-seeking also mediated the age-performance relationship: greater willingness to seek support led to the better academic performance of older students. Other features of the accepted model suggested that students who judged their self-efficacy to be higher expected higher grades and that these highly optimistic expectations led to less support-seeking. Academic worries and internal control beliefs were also found to have positive influences on support-seeking. The model developed accounted for 24% of the variance in students' academic performance. DISCUSSION: Implications for nurse education, and interventions that focus on improving students' academic motivation are discussed in the context of the 'personal teacher' support framework.