Performance of stroke patients on the Middlesex Elderly Assessment of Mental State

As the population of elderly people rises, so too does the incidence of stroke. Cognitive impairment is considered to be a strong predictor of outcome following stroke, and elderly patients may have pre-existing, undiagnosed cognitive impairment as well as impairment caused by the stroke. The present study describes the performance of patients with unilateral hemispheric stroke (right hemisphere, n = 38; left hemisphere, n = 17) on the Middlesex Elderly Assessment of Mental Status (MEAMS), which was developed as a screening tool of cognitive dysfunction for elderly patients.1 Patients had no documented evidence of premorbid cognitive impairment. All patients with scores at borderline or below (n = 7) had language impairment and thus had difficulty with the language-oriented tests. Differences between right and left hemisphere groups are also presented and their performance on the various subtests discussed. It is concluded that the MEAMS is a useful instrument in screening stroke patients for cognitive impairment.

Is there a central executive deficit after severe head injury?

This study examines whether head-injured people have a central executive deficit, and if this is correlated with performance on frontal-lobe tests. Twenty-five severely head-injured (HI) patients and 25 matched controls performed five tasks:(1) visual-motor tracking, (2) digit span, (3) visual-motor tracking with verbal encouragement from the experimenter, (4) visual-motor tracking whilst holding a conversation with the experimenter, and (5) visual-motor tracking with a simultaneous digit-span task. In addition, all subjects were assessed on three frontal-lobe tests. HI patients were significantly worse overall than controls. The most striking difference was in tracking with conversation, in which HI patients (but not controls) showed a marked decrement in performance. Scores from tests of frontal lobe functioning were significantly correlated with (1) tracking during conversation and (2) tracking with digits. The results are broadly consistent with a central executive deficit in head-injured patients.

A memory group for individuals with brain injury

Five patients with memory impairments resulting from brain injury attended a memory group which ran weekly for 11 months. The group focused on helping patients find ways of utilizing memory aids to help with everyday memory problems. Memory games were used to encourage patients to devise strategies for dealing with novel problems. One aim was to facilitate social support amongst patients and opportunities were taken to address the emotional consequences of memory impairment. There were changes in the pattern of use of memory aids and these are discussed. Memory functioning as measured by a memory test (RBMT) did not show any significant improvements. There were some reductions in levels of general anxiety and depression over the course of the group. Patients' feedback indicated that being in a group with others with similar difficulties was both helpful and enjoyable. The advantages of a group run over a longer period than is usual are discussed.

High-throughput screen identifies novel inhibitors of cancer biomarker α-methylacyl coenzyme A racemase (AMACR/P504S)

α-methylacyl coenzyme A racemase (AMACR) is a metabolic enzyme whose overexpression has been shown to be a diagnostic indicator of prostatic adenocarcinoma and other solid tumors. Here, we confirm that attenuation of AMACR expression diminishes the growth of prostate cancer cell lines by using stably expressed short-hairpin RNA constructs. This observation strongly suggests that the AMACR enzyme may be a target for therapeutic inhibition in prostate cancer. To this end, we report here a novel assay capable of screening libraries of diverse small molecules for inhibitors of AMACR activity. This assay facilitated the screening of approximately 5,000 unique compounds and the discovery of 7 distinct chemical entities capable of inhibiting AMACR at low micromolar concentrations. The most potent inhibitor discovered is the seleno-organic compound ebselen oxide [inhibitory concentration (IC(50)): 0.80 μmol/L]. The parent compound, ebselen (IC(50): 2.79 μmol/L), is a covalent inactivator of AMACR (K(I)((inact)): 24 μmol/L). Two of the AMACR inhibitors are selectively toxic to prostate cancer cell lines (LAPC4/LNCaP/PC3) that express AMACR compared to a normal prostate fibroblast cell line (WPMY1) that does not express the protein. This report shows the first high-throughput screen for the discovery of novel AMACR inhibitors, characterizes the first nonsubstrate-based inhibitors, and validates that AMACR is a viable chemotherapeutic target in vitro.

Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.

Nanoscale magnetic field detection using a spin torque oscillator

Magnetic field detection with extremely high spatial resolution is crucial to applications in magnetic storage, biosensing, and magnetic imaging. Here, we present the concept of using a spin torque oscillator (STO) to detect magnetic fields by measuring the frequency of the oscillator. This sensor's performance relies predominantly on STO properties such as spectral linewidth and frequency dispersion with magnetic field, rather than signal amplitude as in conventional magnetoresistive sensors, and is shown in measured devices to achieve large signal to noise ratios. Using macrospin simulations, we describe oscillator designs for maximizing performance, making spin torque oscillators an attractive candidate to replace more commonly used sensors in nanoscale magnetic field sensing and future magnetic recording applications.

A 5-year follow-up study of an atypical case of myotonic dystrophy

This study presents 5-year follow-up data on NG, a woman with adult onset myotonic dystrophy and progressive cognitive decline who was first described by Wilson et al. The extent of the cognitive impairment is atypical of symptom-onset in adulthood and of paternal inheritance, both of which apply to this case. Together, the present and earlier studies report the results of regular neuropsychological assessments over a 16-year period. Severe impairment in executive functioning, episodic and semantic memory were apparent early in the history, while visuospatial skills and working memory were only mildly impaired after 16 years of follow-up. There was also a progressive dyslexia, initially characterized by the regularization errors typical of surface dyslexia, but subsequently dominated by visual/phonological reading errors. This pattern of impairment is not typical of myotonic dystrophy but resembles semantic dementia. Whilst the deficits may be attributable wholly to myotonic dystrophy pathology, the co-existence of a form of semantic dementia is also possible. It is noted that the aggregation of tau protein is a neuropathological feature common to both diseases.

Undergraduate research. Genomics Education Partnership

The Genomics Education Partnership offers an inclusive model for undergraduate research experiences incorporated into the academic year science curriculum, with students pooling their work to contribute to international data bases.

Undergraduate research. Genomics Education Partnership

The Genomics Education Partnership offers an inclusive model for undergraduate research experiences incorporated into the academic year science curriculum, with students pooling their work to contribute to international data bases.

Compensatory strategies for acquired disorders of memory and planning: differential effects of a paging system for patients with brain injury of traumatic versus cerebrovascular aetiology

BACKGROUND

Previous studies have demonstrated the effectiveness of paging systems in compensating for everyday memory and planning problems after brain injury, including in individuals with traumatic brain injury (TBI).

METHODS

Here, in addition to further analyses of the TBI data from a previous randomised control crossover trial, results are reported from a sub-group of 36 participants with brain injury from cerebrovascular accident (CVA).

RESULTS

Results indicate that, as with the TBI group, the pager was effective. However, the pattern of results following cessation of treatment differed. At a group level, TBI participants demonstrated maintenance of pager-related benefits, whereas CVA participants' performance returned to baseline levels. Comparisons of demographic and neuropsychological characteristics of the groups showed that the CVA group was older, had a shorter interval post-injury, and had poorer executive function than the TBI group. Furthermore, within the TBI group, maintenance was associated with executive functioning, such that executive dysfunction impeded maintenance. This correlation remained after controlling for demographic differences between groups.

CONCLUSIONS

Together, these findings suggest that executive dysfunction may affect treatment-for example, whether or not temporary use of the pager is sufficient to establish a subsequently self-sustaining routine.

The European Brain Injury Questionnaire (EBIQ) as a reliable outcome measure for use with people with brain injury

PRIMARY PURPOSE

There is a need to develop reliable outcome measures to determine well-being after brain injury. In 1997, Teasdale et al. published the European Brain Injury Questionnaire (EBIQ), a self-report and relative-report measure of the subjective experience of cognitive, emotional and social difficulties experienced by people with brain injury. It is now used in several rehabilitation centres as an outcome measure, but its test-re-test reliability has yet not been determined. The primary purpose of the present study is to establish this degree of reliability.

RESEARCH DESIGN

The EBIQ was administered twice within an approximately 1-month period to 50 people with brain injury, to 20 relatives of people with brain injury and to 51 normal controls.

RESULTS

The results showed significant and satisfactory test-re-test reliabilities for all three groups across all nine EBIQ scales (r = 0.55-0.90).

CONCLUSION

It is concluded that the EBIQ is a clinically reliable measure to determine the subjective well-being of people with brain injury and to assess change of subjective concerns over time.

Using a paging system in the rehabilitation of encephalitic patients

Memory and executive problems following encephalitis are common yet there are few published papers on the successful rehabilitation of such patients. We recently demonstrated (Wilson, Emslie, Quirk, & Evans, 2001; Wilson, Emslie, Quirk, Evans, & Watson, 2005) that a paging system could reduce the everyday memory and planning problems for people with non-progressive brain injury. Among the 143 patients who participated in the 2001 study were four people who had survived encephalitis. Their results are reported here. During a 2-week baseline, the successful task achievement of our four clients ranged from 2-81%. They then received a pager for 7 weeks and task achievement was documented in weeks 6 and 7. All were significantly more successful with the pager than they had been at baseline with success rates ranging from 45-96%. Five weeks after returning their pagers they were monitored once more. One of the encephalitic patients failed to achieve any of his target tasks, returning to baseline level, the other three dropped back a little but were still significantly more successful than at baseline. It is concluded that the paging system can reduce everyday memory and planning problems of patients with encephalitis.

Longitudinal assessment of awareness in early-stage Alzheimer's disease using comparable questionnaire-based and performance-based measures: a prospective one-year follow-up study

Few studies of awareness in dementia have taken a longitudinal perspective, yet exploring the ways in which awareness changes over time may offer important information about the processes involved and the relationship between awareness and other variables. The present study explored in detail the patterns of change in awareness scores over time for a group of 12 participants with early-stage Alzheimer's disease using a multi-dimensional measure giving comparable participant-carer and post diction-performance discrepancy scores. There were small, non-significant increases in mean discrepancy scores for each of these components of the assessment, with similar patterns for questionnaire-based and performance-based ratings. The small changes that were observed reflected both participant and informant factors. The majority of participants showed only very minor changes; others showed changes in the direction of either reduced or increased awareness. There was no significant association between change in mean discrepancy score and change in MMSE score over time, although there was a significant decline in MMSE scores at follow-up. The observation of different longitudinal trajectories for awareness scores, reflecting increased or decreased awareness or no change, may indicate the operation of different processes affecting the expression of explicit awareness that can be understood within a biopsychosocial formulation of this complex construct.

Population fluctuations of the New Holland mouse Pseudomys novaehollandiae at Wilson?s Promontory National Park, Victoria

The New Holland mouse (Pseudomys novaehollandiae) was first recorded at Wilson?s Promontory in 1972 in heathland vegetation, but has not been located in this habitat subsequently. The species was not trapped again until 1993 when it was found in calcarenite dune woodland on the Yanakie Isthmus. The aims of this study were to assess the population dynamics and habitat use of the species in this dune habitat. Mark-recapture trapping was conducted at three sites from 1999 to 2002. One site was located on low (0 - 5 m), flat sand dunes and open swales, another on medium (5 ? 10 m) vegetated dunes, and the third on high (20 m) steep vegetated dunes. The three sites had not been burnt for 30 to 50 years. The abundance of P. novaehollandiae was related to understorey vegetation density and differences in population densities on the sites are likely to be related to the primary succession stages on the sand dunes, rather than fire history. The maximum density (24 ha-1) recorded at one site was very high compared to other Victorian populations, however this was followed by a substantial decline in numbers within the year. At another site a small population declined to extinction. Populations on the isthmus are thus capable of achieving high densities but may decline quickly. Rainfall patterns may have affected the population fluctuations, but further research is required to elucidate fully the factors involved in the long-term dynamics of this species.

Pasteurella multocida toxin as a tool for studying Gq signal transduction

Pasteurella multocida toxin (PMT) stimulates and subsequently uncouples phospholipase C (PLC) signal transduction through its selective action on the Galphaq subunit. This review summarizes what is currently known about the molecular action of PMT on Gq and the resulting cellular effects. Examples are presented illustrating the use of PMT as a powerful tool for dissecting the molecular mechanisms involving pertussis toxin (PT)-insensitive heterotrimeric G proteins.

Emotional adjustment following cognitive recovery from 'persistent vegetative state': psychological and personal perspectives

Previously, the cognitive recovery of a 26 year old woman, Kate, who developed a severe encephalomyelopathy and was in a 'minimally conscious/persistent vegetative state' for 6 months was reported. After 6 months, Kate began to respond to her environment and, at 2 years post-illness, neuropsychological assessment indicated that Kate was functioning within the normal range on tests of general intellectual functioning, executive functioning and most memory functions (with the exception of visual recognition memory). Although Kate has a severe dysarthria necessitating the use of a communication board and severe physical disabilities that require her to use a wheelchair, she has demonstrated an almost complete cognitive recovery and is among a tiny percentage of minimally conscious patients to do so. This single case report describes the emotional factors central to Kate's rehabilitation. Using a newly developed model of cognitive rehabilitation as a framework, the pivotal role that emotional and psychological factors played in Kate's adjustment to the consequences of her illness and the role of psychotherapeutic intervention in facilitating this adjustment are discussed.

Neurorehabilitation for two cases of post-traumatic stress disorder following traumatic brain injury

INTRODUCTION

We present two cases to illustrate the assessment and management of post-traumatic stress disorder (PtSD) in the context of traumatic brain injury (TBI). Case KE suffered a TBI in a road traffic accident (RTA) in which his girlfriend was killed. Case CM survived a penetrating neurological injury from a severe knife attack. Both suffered cognitive difficulties, primarily in attention and memory, and selective visual impairments, and had endured significant losses of social role.

METHOD

Within a neurorehabilitation programme, goals were set regarding management of their cognitive difficulties for regaining social roles and for the management of their PtSD symptoms. Cognitive behavioural therapy (CBT) was provided for managing PtSD symptoms, which included use of a stress inoculation and graduated exposure to avoided situations and trauma re-experiences.

RESULTS

Both survivors reported significant improvements in managing mood state, and in redeveloping social roles. Objective measures confirmed significant gains from intervention.

CONCLUSIONS

CBT, set within a neurorehabilitation programme, can lead to improvement in PtSD symptoms and psychosocial outcome in TBI survivors.

Cognitive rehabilitation as a component of early intervention in Alzheimer's disease: a single case study

Early intervention in Alzheimer's disease (AD) should focus on psychological and social needs as well as the provision of medication. One possible component of early intervention programmes for people with early-stage AD is cognitive rehabilitation aimed at fostering the development of strategies for coping with memory problems. The likely relevance of cognitive rehabilitation in early-stage AD is supported by neuropsychological and experimental learning studies, but further work is required to develop clinically relevant interventions, which can be applied in the real-life setting. This paper presents a single case intervention study in which a 66-year-old man with early-stage AD learned the names of 13 members of his support group using a mnemonic strategy coupled with either expanding rehearsal or repeated presentation, or both, within an errorless learning paradigm. Recall scores improved from a mean of 2.31% at initial baseline to 91.46% following intervention, and gains were largely maintained at follow-up. There was no evidence of any increase in depression, anxiety or caregiver strain during the intervention. The results support the view that cognitive rehabilitation interventions may form a valuable component of comprehensive early intervention programmes for people with AD.

Habitat characteristics for New Holland mouse Pseudomys novaehollandiae in Victoria

Pseudomys novaehollandiae is ‘Endangered’ in Victoria, where it is presently considered to be extant at only three localities Loch Sport, Providence Ponds, and Wilsons Promontory. This study aimed to determine indicators of suitable habitat for the species that could assist in identifying potential habitat and sites for planned re-introductions as part of a recovery program. Vegetation and site data (soils, topography, rainfall, fire age-time since fire) were assessed at localities where P. novaehollandiae was recorded. The species occurred in five structural vegetation groups - open-forest, woodland, heathland, shrubland, grassland, with the most common being open-forest and woodland. Grassland and shrubland were restricted to coastal sand-dunes in south Gippsland. Understorey vegetation at most sites was dominated by sclerophyllous shrubs ranging in cover from 10 - 70%. Classification of quadrats produced eight floristic groups in which the trend was for quadrats to cluster according to geographical location. Ordination confirmed the classification pattern and vector-fitting produced significant correlations between vector points and five variables: species richness, latitude, longitude, fire age and annual rainfall. The study identified a range of vegetation communities where P. novaehollandiae occurs and provided evidence that the species is not restricted to floristically rich and diverse heathlands. The findings can be used to determine further localities with suitable habitat. However, factors other than vegetation are also likely to be important in predicting suitable habitat.

Brief report: prevalence of post-traumatic stress disorder symptoms after severe traumatic brain injury in a representative community sample

PRIMARY OBJECTIVE

In this study, the authors investigated the prevalence of symptoms of post-traumatic stress disorder (PTSD) in a community sample of 66 survivors of severe traumatic brain injury (TBI). RESEARCH DESIGN, METHODS AND PROCEDURES: A representative sample of survivors of TBI were selected on the basis of having suffered significant disturbance in consciousness following their trauma event in the form of coma and/or post-traumatic amnesia. Neuropsychological testing confirmed that participants had suffered cognitive deficits consistent with severe brain injury. Participants were administered the Impact of Events inventory for symptoms of PTSD.

MAIN OUTCOMES AND RESULTS

The authors found a prevalence rate of 18% for moderate-to-severe PTSD symptoms.

CONCLUSIONS

PTSD symptoms are common following severe TBI. Further research is needed to establish protective and predictive factors for PTSD in TBI groups.

G(q/11) is involved in insulin-stimulated inositol phosphoglycan putative mediator generation in rat liver membranes: co-localization of G(q/11) with the insulin receptor in membrane vesicles

Insulin signaling to generate inositol phosphoglycans (IPGs) was demonstrated to occur via the participation of the heterotrimeric G-proteins G(q/11). IPGs were measured as two specific inositol markers, myo-inositol and chiro-inositol after strong acid hydrolysis. Insulin and Pasteurella multocida toxin (PMT) generated both myo-inositol and chiro-inositol IPGs in a dose-dependent manner. PMT has been shown to activate G(q) specifically. Insulin action was abrogated by pre-treatment with anti G(q/11) antibody. Western blotting demonstrated the enrichment of both insulin receptor beta subunit and G(q/11) in the liver membrane vesicles. Vesicles also contained clathrin, caveolin PLC beta 1 and PLC Delta. Immunogold staining revealed the co-localization of both insulin receptor beta subunit and G(q/11) in an approximate stochiometric ratio of 1:3. No vesicles were detected with either component alone. The present and considerable published data provide strong evidence for insulin signaling both via a tyrosine kinase cascade mechanism and via heterotrimeric G-protein interactions.

Atrazine potentiation of arsenic trioxide-induced cytotoxicity and gene expression in human liver carcinoma cells (HepG2)

Recent studies in our laboratory indicated that arsenic trioxide has the ability to cause significant cytotoxicity, and induction of a significant number of stress genes in human liver carcinoma cells, HepG2. However, similar investigations with atrazine did not show any significant effects of this chemical on HepG2 cells, even at its maximum solubility of 100 microg/mL in 1% dimethyl sulfoxide (DMSO). Further cytogenetic studies were therefore carried out to investigate the combined effects of arsenic trioxide and atrazine on cell viability and gene expression in immortalized human hepatocytes. Cytotoxicity was evaluated using the MTT-assay for cell viability, while the CAT-Tox (L) assay was performed to measure the induction of stress genes in thirteen different recombinant cell lines generated from human liver carcinoma cells (HepG2), by creating stable transfectants of different mammalian promoter-chloramphenicol acetyltransferase (CAT) gene fusions. Cytotoxicity experiments yielded LC50 values of 11.9 +/- 2.6 microg/mL for arsenic trioxide in de-ionized water, and 3.6 +/- 0.4 microg/mL for arsenic trioxide in 100 microg/mL atrazine; indicating a 3 fold increase in arsenic toxicity associated with the atrazine exposure. Co-exposure of HepG2 cells to atrazine also resulted in a significant increase in the potency of arsenic trioxide to upregulate a number of stress genes including those of the glutathione-S-transferase Ya subunit--GST Ya, metallothioneinIIa--HMTIIA, 70-kDa heat shock protein--HSP70, c-fos, 153-kDa growth arrest and DNA damage (GADD153), 45-kDa growth arrest and DNA damage (GADD45), and 78-kDa glucose regulated protein--GRP78 promoters, as well as the xenobiotic response element--XRE, tumor suppressor protein response element--p53RE, cyclic adenosine monophosphate response element--CRE, and retinoic acid response element--RARE. No significant changes were observed with respect to the influence of atrazine on the modulation of cytochrome P450 1A1-CYP 1A1, and nuclear factor kappa (B site) response element--NFkappaBRE by arsenic trioxide. These results indicate that co-exposure to atrazine strongly potentiates arsenic trioxide-induced cytotoxicity and transcriptional activation of stress genes in transformed human hepatocytes.

Cognitive recovery from "persistent vegetative state": psychological and personal perspectives

This study reports on the case of a young woman who, at the age of 26, developed a severe encephalomyelopathy and was in a vegetative state or minimally conscious state for 6 months. She showed a sleep-wake cycle, but no evidence of cognitive functioning. Six months after her illness, she began to respond to her environment and eventually returned home to the care of her parents, with regular periods of respite care in a home for people with severe physical disabilities. She remains in a wheelchair with a severe dysarthria and communicates via a letter board. Two years after her illness, staff at the home requested an assessment of her cognitive functioning. On the WAIS-R verbal scale and the Raven's Progressive Matrices, the woman's scores were in the normal range. So too were her recognition of real versus nonsense words and her memory functioning (apart from a visual recognition memory test which was in the impaired range). Although she enjoyed the tests, she became distressed when asked about her illness and previous hospitalization. She was reassessed 1 year later, when there were few significant changes in her test scores but she could talk about her illness and hospitalization without becoming distressed. She was angry, however, about her experiences in the first hospital. Further tests suggested good executive functioning. In short, this woman's cognitive functioning is in the normal range for most tasks assessed, despite a severe physical disability and dysarthria, and despite the fact that she was vegetative for 6 months. Although some recovery following 6 months of being vegetative/minimally conscious is not unknown, it is rare, particularly for those with non-traumatic injuries, and the majority of people similarly affected remain with significant cognitive deficits. This client has, by and large, made an almost complete cognitive recovery. She feels positive about her life now and says the formal assessment showed people she was not stupid and this made her happy. The paper concludes with the young woman's own comments and views about what happened to her and her present feelings.

Evaluation of accuracy and reliability of indirect calorimetry for the measurement of resting energy expenditure in healthy dogs

OBJECTIVE

To assess accuracy and reliability of open-flow indirect calorimetry in dogs.

ANIMALS

13 clinically normal dogs.

PROCEDURE

In phase 1, oxygen consumption per kilogram of body weight (VO2/kg) was determined in 6 anesthetized dogs by use of open-flow indirect calorimetry before and after determination of VO2/kg by use of closed-circuit spirometry. In phase 2, four serial measurements of VO2 and carbon dioxide production (VCO2) were obtained in 7 awake dogs by use of indirect calorimetry on 2 consecutive days. Resting energy expenditure (REE) was calculated.

RESULTS

Level of clinical agreement was acceptable between results of indirect calorimetry and spirometry. Mean VO2/kg determined by use of calorimetry before spirometry was significantly greater than that obtained after spirometry. In phase 2, intraclass correlation coefficients (ICC) for REE and VO2 were 0.779 and 0.786, respectively, when data from all 4 series were combined. When the first series was discounted, ICC increased to 0.904 and 0.894 for REE and VO2, respectively. The most reliable and least variable measures of REE and VO2 were obtained when the first 2 series were discounted.

CONCLUSIONS AND CLINICAL RELEVANCE

Open-flow indirect calorimetry may be used clinically to obtain a measure of VO2 and an estimate of REE in dogs. Serial measurements of REE and VO2 in clinically normal dogs are reliable, but a 10-minute adaption period should be allowed, the first series of observations should be discounted, multiple serial measurements should be obtained, and REE.

Interaction of hand use and spatial selective attention in children

It has been argued that concurrent motor action can modulate visual spatial attention. The visual spatial biases of adult patients with unilateral neglect, for example, can be ameliorated by simultaneous use of the contralesional hand. Such improvements are most dramatic when the contralesional hand is moved within contralesional space. To date, evidence of such an interaction in neurologically healthy individuals has not been presented. Line bisection is a simple task that is sensitive to attentional spatial bias. When young children are asked to bisect horizontal lines using their right hands, they show a reliable, if small, bias that is consistent with the pattern seen in adult neglect. This bias is reversed when the left hand is used. Here, we show that these effects are significantly modulated by the location of the movements relative to the body mid-line - specifically that the conjunction of hand movements within ipsilateral space is necessary for the previously reported pattern to be observed. We further demonstrate that these effects are not present in the bisections of neurologically healthy adults. In a final study, we examined whether the hand movement effects seen in children's line bisections would persist in a purely visual task (that is when the movements were made irrelevant to the response). Again, significant modulation of children's perception by concurrent hand movements - and the relative location of those movements - was observed. The theoretical and clinical implications of the results are discussed.

The effects of increased rehabilitation therapy after brain injury: results of a prospective controlled trial

OBJECTIVE

The objective was to investigate the effect of increased intensity of rehabilitation therapy provided to brain-injured subjects on the rate at which independence was regained and the duration of hospital admission.

DESIGN

A two-centre, prospective, controlled study with random allocation to groups.

SETTING

Two district general hospitals on the south coast of England.

SUBJECTS

Fifty-six people with moderate and severe head injury consecutively admitted to Southampton and Poole hospitals between June 1995 and September 1997.

INTERVENTIONS

Increased intensity of rehabilitation therapy input without change in content.

RESULTS

Subjects receiving more intensive therapy made more rapid progress and were discharged home sooner. The different intensities of therapy employed in this study showed no evidence of a 'ceiling' effect and the 'intervention group' made significantly more rapid progress on tests of dependency during the period of admission. A clear response to increased therapy input was seen in one of the centres with more rapid functional improvement and a shorter length of hospital stay. This centre already had more therapy and better community facilities. No such benefits were seen at the other centre where the intervention group had a longer hospital stay than the routine group.

CONCLUSION

Increasing the hours per week of therapy given to adults recovering from brain injury in hospital can accelerate the rate of recovery of personal independence and result in their being discharged from hospital sooner. Increased rehabilitation therapy after brain injury is associated with enhanced functional recovery and shorter hospital stay if provided in the context of an integrated service that can provide ongoing community support. There is no evidence of any ceiling effect of therapeutic intensity beyond which no further response is observed.

Atrazine potentiation of arsenic trioxide-induced cytotoxicity and gene expression in human liver carcinoma cells (HepG2)

Recent studies in our laboratory indicated that arsenic trioxide has the ability to cause significant cytotoxicity, and induction of a significant number of stress genes in human liver carcinoma cells, HepG2. However, similar investigations with atrazine did not show any significant effects of this chemical on HepG2 cells, even at its maximum solubility of 100 microg/mL in 1% dimethyl sulfoxide (DMSO). Further cytogenetic studies were therefore carried out to investigate the combined effects of arsenic trioxide and atrazine on cell viability and gene expression in immortalized human hepatocytes. Cytotoxicity was evaluated using the MTT-assay for cell viability, while the CAT-Tox (L) assay was performed to measure the induction of stress genes in thirteen different recombinant cell lines generated from human liver carcinoma cells (HepG2), by creating stable transfectants of different mammalian promoter-chloramphenicol acetyltransferase (CAT) gene fusions. Cytotoxicity experiments yielded LC50 values of 11.9 +/- 2.6 microg/mL for arsenic trioxide in de-ionized water, and 3.6 +/- 0.4 microg/mL for arsenic trioxide in 100 microg/mL atrazine; indicating a 3 fold increase in arsenic toxicity associated with the atrazine exposure. Co-exposure of HepG2 cells to atrazine also resulted in a significant increase in the potency of arsenic trioxide to upregulate a number of stress genes including those of the glutathione-S-transferase Ya subunit--GST Ya, metallothioneinIIa--HMTIIA, 70-kDa heat shock protein--HSP70, c-fos, 153-kDa growth arrest and DNA damage (GADD153), 45-kDa growth arrest and DNA damage (GADD45), and 78-kDa glucose regulated protein--GRP78 promoters, as well as the xenobiotic response element--XRE, tumor suppressor protein response element--p53RE, cyclic adenosine monophosphate response element--CRE, and retinoic acid response element--RARE. No significant changes were observed with respect to the influence of atrazine on the modulation of cytochrome P450 1A1-CYP 1A1, and nuclear factor kappa (B site) response element--NFkappaBRE by arsenic trioxide. These results indicate that co-exposure to atrazine strongly potentiates arsenic trioxide-induced cytotoxicity and transcriptional activation of stress genes in transformed human hepatocytes.

Transcriptional activation of stress genes and cytotoxicity in human liver carcinoma cells (HepG2) exposed to 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene

The CAT-Tox (L) assay has recently been developed and validated for detecting and quantifying the specific molecular mechanisms that underlie toxicity of various xenobotic chemicals. We performed this assay to measure the transcriptional responses associated with 2,4,6-trinitrotoluene (TNT) and 2 of its byproducts [2,4 and 2,6-dinitotoluenes (DNTs)] to 13 different recombinant cell lines generated from human liver carcinoma cells (HepG2) by creating stable transfectants of mammalian promoter chloramphenicol acetyltransferase (CAT) gene fusions. Cytoxicity test with the parental HepG2 cells, using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]-based assay for cell viability, yielded LC50 values of 105 +/- 6 mg/mL for TNT in 1% dimethyl sulfoxide (DMSO), and > 300 mg/mL for DNTs, upon 48 h of exposure. TNT appeared to be more toxic than 2,4-DNT, which also showed a higher toxicity compared to 2,6-DNT. Of the 13 recombinant constructs evaluated, 8 (CYP 1A1, GST Ya, XRE, HMTIIA, c-fos, HSP70, GADD153, and GADD45), 5 (c-fos, HSP70, GADD153, GADD45, and GRP78), and none showed inductions to significant levels (p < 0.05), for TNT, 2,4-DNT, and 2,6-DNT, respectively. For most constructs, the induction of stress genes was concentration-dependent. These results show the potential for TNT and 2,4-DNT to cause protein damage and/or perturbations of protein biosynthesis (HSP70 and GRP78), alterations in DNA sequence or its helical structure (c-fos, GADD153, GADD45), and the potential involvement of TNT in the biotransformation process (CYP 1A1, GST Ya, XRE), and in the toxicokinetics of metal ions (HMTIIA). Within the range of concentrations tested (0-300 mg TNT or DNT/mL in 1% DMSO), no significant inductions (p > 0.05) of NFKBRE, p53RE, CRE, and RARE were found.

Perceptions of pain in women with headache: a laboratory investigation of the influence of pain-related anxiety and fear

The present study compared the responses of women with headache (chronic tension-type, n = 27; migraine, n = 27) and controls (n = 27) to an acute pain laboratory task, the cold pressor test. Participants' pain perception (i.e., threshold and tolerance) and their fear/anxiety associated with pain were assessed during days 1, 2, or 3 of menses. Analyses pertaining to participants' responses to the cold pressor test (ie, pain threshold and tolerance) failed to show statistically significant group differences, even when covarying pain-related anxiety/fear. Analyses did, however, reveal significant group differences between migraineurs and controls in cognitive anxiety. Correlational analyses also revealed that cognitive anxiety, somatic anxiety, fear, and escape/avoidance were all significantly correlated with pain tolerance in the group with chronic tension-type headache, but not in the other two groups. Subsequent multiple regressions, however, showed that the relationship between anxiety and pain tolerance was primarily a function of somatic anxiety. These results suggest that headache frequency plays a role in mediating the relationship between fear of pain and pain tolerance and that the models by Lethem and colleagues and McCracken may be relevant for understanding tension headache sufferers' responses to head pain.

Reducing everyday memory and planning problems by means of a paging system: a randomised control crossover study

OBJECTIVES

To evaluate a paging system designed to improve independence in people with memory problems and executive deficits.

METHODS

After a successful pilot study, a randomised control trial was conducted involving a crossover design with 143 people aged between 8 and 83 years. All had one or more of the following: memory, planning, attention, or organisation problems. Most had sustained a traumatic head injury or a stroke although a few had developmental learning difficulties or other conditions. The crossover design ensured that some people received a pager after a 2 week baseline whereas others were required to wait for 7 weeks after the baseline before receiving the pager. Participants were assessed at three time periods-namely, at baseline, 7 weeks, and at 14 weeks postbaseline.

RESULTS

More than 80% of those who completed the 16 week trial were significantly more successful in carrying out everyday activities (such as self care, self medication, and keeping appointments) when using the pager in comparison with the baseline period. For most of these, significant improvement was maintained when they were monitored 7 weeks after returning the pager.

CONCLUSIONS

This particular paging system significantly reduces everyday failures of memory and planning in people with brain injury.

Compensating for cognitive deficits following brain injury

Two of the most important goals of rehabilitation are to (a) reduce everyday consequences of impaired cognitive functioning (disabilities) and (b) reduce the level of handicap (the extent to which these problems prevent successful return to society). One of the ways by which we can achieve these goals is to enable people to compensate for their cognitive deficits. This paper (i) describes a theoretical framework for understanding compensatory behavior, (ii) discusses different forms of compensation, (iii) considers compensation for several cognitive disorders, and (iv) presents suggestions for predicting which patients will find it easy to compensate and which require more intensive and focused rehabilitation.

Adapting the Rivermead Behavioural Memory Test Extended Version (RBMT-E) for people with restricted mobility

OBJECTIVES

The study aimed to facilitate use of the RBMT-E with people who have impaired mobility by devising substitute tasks for the route and message subtests that do not require the individual to move around, and by presenting normative data for these substitute tasks.

DESIGN

A within-subjects design was used to assess a standardization sample. Participants completed two parallel versions of the tasks in counter-balanced order in two test sessions approximately 1 week apart.

METHODS

Substitute versions of the route and message subtests not requiring the individual to move around the test room were devised using commercially available materials. These were administered to participants along with other RBMT-E subtests. Scores for each version were compared for the group as a whole and for subgroups divided according to age, gender and IQ. Based on the results, profile scores were derived for each task using box plot analysis. The participants (N = 111) were part of the standardization sample for the RBMT-E and comprised consecutive series of recruits in two centres, Cambridge (UK) and Sydney (Australia).

RESULTS

Normative data are presented in the form of mean scores for the group as a whole, for men and women, for people aged under 30, 30 to 50, and over 50 years, and for people with an IQ of either 90-110 or over 110. Profile score transformations for the substitute tasks are provided.

CONCLUSIONS

Where mobility problems preclude the use of the route and message subtests of the RBMT-E, the 'model' tasks described here can be substituted and profile scores calculated. This allows clinicians to obtain a full spectrum of subtest scores for the RBMT-E with mobility-impaired patients, thus allowing the calculation of a total profile score.

Lithium and protein kinase C modulators regulate swelling-activated K-Cl cotransport and reveal a complete phosphatidylinositol cycle in low K sheep erythrocytes

K-Cl cotransport (COT), a ouabain-insensitive, Cl-dependent bidirectional K flux, is ubiquitously present in all cells, plays a major role in ion and volume homeostasis, and is activated by cell swelling and a variety of chemical interventions. Lithium modulates several cation transport pathways and inhibits phospholipid turnover in red blood cells (RBCs). Lithium also inhibits K-Cl COT by an unknown mechanism. To test the hypothesis whereby Li inhibits swelling-activated K-Cl COT by altering either its osmotic response, its regulation, or by competing with K for binding sites, low K (LK) sheep (S) RBCs were loaded with Li by Na/Li exchange or the cation ionophore nystatin. K-Cl COT was measured as the Cl-dependent, ouabain-insensitive K efflux or Rb influx. The results show that Li altered the cell morphology, and increased both cell volume and diameter. Internal (Li(i)) but not external (Li(o)) Li inhibited swelling-activated K-Cl COT by 85% with an apparent K(i) of approximately 7 mm. In Cl, Li(i) decreased K efflux at relative cell volumes between 0.9 and 1.2, and at external pHs between 7.2 and 7.4. Li(i) reduced the V(max) and increased the K(m) for K efflux in Cl. Furthermore, Li(i) increased the production of diacylglycerol in a bimodal fashion, without significant effects on the phosphatidylinositol concentration, and revealed the presence of a complete PI cycle in LK SRBCs. Finally, phorbol ester treatment and PD89059, an inhibitor of mitogen-activated protein kinase (ERK2) kinase, caused a time-dependent inhibition of K-Cl COT. Hence, Li(i) appears to inhibit K-Cl COT by acting at an allosteric site on the transporter or its putative regulators, and by modulation of the cellular phospholipid metabolism and a PKC-dependent regulatory pathway, causes an altered response of K-Cl COT to pH and volume.

Differential modulation and subsequent blockade of mitogenic signaling and cell cycle progression by Pasteurella multocida toxin

The intracellularly acting protein toxin of Pasteurella multocida (PMT) causes numerous effects in cells, including activation of inositol 1,4,5-trisphosphate (IP(3)) signaling, Ca(2+) mobilization, protein phosphorylation, morphological changes, and DNA synthesis. The direct intracellular target of PMT responsible for activation of the IP(3) pathway is the G(q/11)alpha-protein, which stimulates phospholipase C (PLC) beta1. The relationship between PMT-mediated activation of the G(q/11)-PLC-IP(3) pathway and its ability to promote mitogenesis and cellular proliferation is not clear. PMT stimulation of p42/p44 mitogen-activated protein kinase occurs upstream via G(q/11)-dependent transactivation of the epidermal growth factor receptor. We have further characterized the effects of PMT on the downstream mitogenic response and cell cycle progression in Swiss 3T3 and Vero cells. PMT treatment caused dramatic morphological changes in both cell lines. In Vero cells, limited multinucleation, nuclear fragmentation, and disruption of cytokinesis were also observed; however, a strong mitogenic response occurred only with Swiss 3T3 cells. Significantly, this mitogenic response was not sustained. Cell cycle analysis revealed that after the initial mitogenic response to PMT, both cell types subsequently arrested primarily in G(1) and became unresponsive to further PMT treatment. In Swiss 3T3 cells, PMT induced up-regulation of c-Myc; cyclins D1, D2, D3, and E; p21; PCNA; and the Rb proteins, p107 and p130. In Vero cells, PMT failed to up-regulate PCNA and cyclins D3 and E. We also found that the initial PMT-mediated up-regulation of several of these signaling proteins was not sustained, supporting the subsequent cell cycle arrest. The consequences of PMT entry thus depend on the differential regulation of signaling pathways within different cell types.

Assessing subtle memory impairments in the everyday memory performance of brain injured people: exploring the potential of the extended Rivermead Behavioural Memory Test

A substantial number of brain injured patients complain of memory deficits, despite achieving scores within the normal range on tests of memory functioning. The Rivermead Behavioural Memory Test is an ecologically valid test used to assess everyday memory problems. This test is effective at detecting moderate to-severe impairments, yet subtle memory deficits may go undetected for some patients who achieve a score within the normal range. The initial development of an extended version of this test (RBMT-E), designed to detect subtle decrements in memory performance, has recently been described. The performance of 16 brain injured patients was assessed on both the RBMT and the KBMT-E. The performance of these patients on the RBMT-E was compared with that of matched controls. Overall, the patients performed significantly worse than the controls, and showed particular difficulty in two subtests involving recalling a route and remembering to deliver a message. Those patients who scored in the 'normal' range on the RBMT could be further differentiated on the basis of their RBMT-E scores into 'good', 'average' and 'poor' performance categories. The patients' performance was not significantly associated with general intellectual ability. These results suggest that the RBMT-E may be a useful clinical tool to aid therapists in the assessment of subtle impairments of everyday memory performance following brain injury.

The Wessex Head Injury Matrix (WHIM) main scale: a preliminary report on a scale to assess and monitor patient recovery after severe head injury

OBJECTIVE

To develop a behavioural assessment based on observations of patients recovering after severe head injury whereby data could be collected by observation and by testing everyday tasks.

DESIGN

A prospective observational study of a cohort of 88 consecutive hospital admissions with severe head injury.

SETTING

Two district general hospitals in the UK.

PATIENTS

Eighty-eight consecutive admissions with severe traumatic head injury. Ages ranged from 14 to 67 years, mean coma duration was 14 days and mean duration of post traumatic amnesia (PTA) was 56 days.

RESULTS

Fifty-eight items of behaviour were identified. Paired preference analysis was used to identify a sequence of recovery of these behaviours. The sequence began with arousal and led on to behaviours signalling recovery of social interaction and communication. Subsequent behaviours indicated increasing cognitive organization and return of orientation and memory. The behaviours on the scale are hierarchical and range from coma to emergence from PTA.

CONCLUSIONS

A scale to assess patients and monitor cognitive recovery after severe head injury has been developed. While individual patients will show some departures from the sequence identified, the scale helps to make explicit the earliest stages of natural recovery patterns after head injury.

Coupling function of endogenous alpha(1)- and beta-adrenergic receptors in mouse cardiomyocytes

Genetically altered mouse models constitute unique systems to delineate the role of adrenergic receptor (AR) signaling mechanisms as modulators of cardiomyocyte function. The interpretation of results from these models depends on knowledge of the signaling properties of endogenous ARs in mouse cardiomyocytes. In the present study, we identify for the first time several defects in AR signaling in cardiomyocytes cultured from mouse ventricles. beta(1)-ARs induce robust increases in cAMP accumulation and the amplitude of the calcium and cell motion transients in mouse cardiomyocytes. Selective beta(2)-AR stimulation increases the amplitude of calcium and motion transients, with only a trivial rise in cAMP accumulation in comparison. beta(2)-AR responses are not influenced by pertussis toxin in cultured mouse cardiomyocytes. alpha(1)-ARs fail to activate phospholipase C, the extracellular signal-regulated protein kinase, p38-MAPK, or stimulate hypertrophy in mouse cardiomyocytes. Control experiments establish that this is not due to a lesion in distal elements in the signaling machinery, because these responses are induced by protease-activated receptor-1 agonists and phospholipase C is activated by Pasteurella multocida toxin (a G(q) alpha-subunit agonist). Surprisingly, norepinephrine activates p38-MAPK via beta-ARs in mouse cardiomyocytes, but beta-AR activation of p38-MAPK alone is not sufficient to induce cardiomyocyte hypertrophy. Collectively, these results identify a generalized defect in alpha(1)-AR signaling and a defect in beta(2)-AR linkage to cAMP (although not to an inotropic response) in cultured mouse cardiomyocytes. These naturally occurring vagaries in AR signaling in mouse cardiomyocytes provide informative insights into the requirements for hypertrophic signaling and impact on the value of mouse cardiomyocytes as a reconstitution system to investigate AR signaling in the heart.

Improvement or simply practice? The effects of twenty repeated assessments on people with and without brain injury

Measuring recovery of function may mean testing the same individual many times, a procedure that is inevitably open to improvement due to learning on the specific tests rather than recovery per se. This is particularly likely to be an issue with measures of memory performance. We therefore studied the performance of normal and brain-injured people across 20 successive test sessions on measures of orientation, simple reaction time, forward and backward digit span, visual and verbal recognition, word list learning and forgetting, and on three semantic memory measures, namely, letter and category fluency and speed of semantic processing. Differences in overall performances between the two groups occurred for all tests other than orientation, digit span forward, and simple reaction time, although the tests differed in their degree of sensitivity. The tests varied in the presence or absence of practice effects and in the extent to which these differed between the two groups. Data are presented that should allow investigators to select measures that are likely to optimize sensitivity while minimizing possible confounding due to practice effects.

Rehabilitation of executive functioning: an experimental-clinical validation of goal management training

Two studies assessed the effects of a training procedure (Goal Management Training, GMT), derived from Duncan's theory of goal neglect, on disorganized behavior following TBI. In Study 1, patients with traumatic brain injury (TBI) were randomly assigned to brief trials of GMT or motor skills training. GMT, but not motor skills training, was associated with significant gains on everyday paper-and-pencil tasks designed to mimic tasks that are problematic for patients with goal neglect. In Study 2, GMT was applied in a postencephalitic patient seeking to improve her meal-preparation abilities. Both naturalistic observation and self-report measures revealed improved meal preparation performance following GMT. These studies provide both experimental and clinical support for the efficacy of GMT toward the treatment of executive functioning deficits that compromise independence in patients with brain damage.

Intervening with everyday memory problems in dementia of Alzheimer type: an errorless learning approach

Dementia of Alzheimer Type (DAT) is increasingly detected at an earlier stage of the disorder, when interventions to assist with everyday memory difficulties might be most valuable. Some learning is possible in DAT and a number of factors have been identified which may facilitate performance, although applications to everyday memory problems have been limited. The concept of errorless learning has not previously been directly examined in relation to DAT, but might provide a useful additional strategy. In the present study, 6 participants with early stage DAT (MMSE scores 21 - 26) received individually tailored interventions, based on errorless learning principles and targeted at a specific everyday memory problem. Five of the participants showed significant improvement on the target measures, and maintained this improvement up to 6 months later. The results suggest that it is feasible to intervene with everyday memory problems in the early stages

Pasteurella multocida toxin stimulates mitogen-activated protein kinase via G(q/11)-dependent transactivation of the epidermal growth factor receptor

The dermatonecrotic toxin produced by Pasteurella multocida is one of the most potent mitogenic substances known for fibroblasts in vitro. Exposure to recombinant P. multocida toxin (rPMT) causes phospholipase C-mediated hydrolysis of inositol phospholipids, calcium mobilization, and activation of protein kinase C via a poorly characterized mechanism involving G(q/11) family heterotrimeric G proteins. To determine whether the regulation of G protein pathways contributes to the mitogenic effects of rPMT, we have examined the mechanism whereby rPMT stimulates the Erk mitogen-activated protein kinase cascade in cultured HEK-293 cells. Treatment with rPMT resulted in a dose and time-dependent increase in Erk 1/2 phosphorylation that paralleled its stimulation of inositol phospholipid hydrolysis. Both rPMT- and alpha-thrombin receptor- stimulated Erk phosphorylation were selectively blocked by cellular expression of two peptide inhibitors of G(q/11) signaling, the dominant negative mutant G protein-coupled receptor kinase, GRK2(K220R), and the Galpha(q) carboxyl-terminal peptide, Galpha(q)-(305-359). Like alpha-thrombin receptor-mediated Erk activation, the effect of rPMT was insensitive to the protein kinase C inhibitor GF109203X, but was blocked by the epidermal growth factor receptor-specific tyrphostin, AG1478 and by dominant negative mutants of mSos1 and Ha-Ras. These data indicate that rPMT employs G(q/11) family heterotrimeric G proteins to induce Ras-dependent Erk activation via protein kinase C-independent "transactivation" of the epidermal growth factor receptor.

Polycythemia decreases fatigue in tetanic contractions of canine skeletal muscle

PURPOSE

The effects of an acute polycythemia on muscle fatigue development were investigated in the self-perfused canine gastrocnemius in situ.

METHODS

Following isolation of the gastrocnemius, dogs (N = 5) were made polycythemic through a bolus injection of packed erythrocytes (hematocrit (Hct) = 90-92%) to raise systemic Hct to 63.5 +/- 0.5%. Subsequently, the gastrocnemius was stimulated, through the sciatic nerve, to perform 20 min of isotonic tetanic contractions (60 x min(-1), 200 ms, 50Hz). Control (normocythemic) animals (N = 5) underwent an identical contraction regimen.

RESULTS

Although blood flow to the gastrocnemius was not different at any time, oxygen delivery was significantly increased during polycythemia (peak = 33.7 +/- 2.2 mL x 100 g(-1) x min-1) over control (peak = 25.1 +/- 2.1 mL x 100 g(-1)x min(-1)) at all times during contraction. Oxygen uptake by the gastrocnemius, although consistently increased, was not significantly different between the normocythemic and polycythemic conditions at any time. The rate of fatigue was significantly decreased over the first 6 min of contraction in polycythemic animals (3.5 +/- 0.6% x min(-1)) when compared with controls (5.8 +/- 0.7% x min(-1)). Subsequent fatigue development was not different between groups. As a result of the early rate differences in fatigue, however, the work production in polycythemic animals was significantly greater than in normocythemic dogs for the duration of the contraction period.

CONCLUSION

We conclude that during high metabolic rate isotonic tetanic contractions, muscle fatigue development is diminished by polycythemia, but the ergogenic effect appears to be transient.

Current management of AIDS and related opportunistic infections

Significant changes in acquired immunodeficiency syndrome (AIDS) epidemiology and AIDS treatment strategies have emerged in the 17 years since the first case of this disease was reported. In the United States, the human immunodeficiency virus (HIV) is now primarily acquired through heterosexual relationships and intravenous drug use. As a result, dramatic increases in the number of AIDS cases in the female, African American, and Hispanic populations are evident. Treatment strategies now focus on maximal viral suppression and preventing drug resistance. Advances in anti-retroviral therapy and chemoprophylaxis of opportunistic infections have increased the long-term survival of AIDS patients by 10 to 20 years. However, despite abundant research and advances in medical care, AIDS continues to be a devastating epidemic worldwide.

Measuring recovery from post traumatic amnesia

Three groups of participants were assessed. Each participant was tested on 20 occasions. The groups comprised people (i) in post traumatic amnesia (PTA) following severe head injury (n=9), (it) with severe head injury but not in PTA (n=10), and (iii) with no history of head injury or other neurological condition (n=13). Subjects were given several tests of memory, attention and learning in order to determine which tests were good at (a) distinguishing people in PTA from those not in PTA, and (b) monitoring recovery over time. The results indicate that people in PTA have a wide range of deficits and their cognitive recovery is a gradual process rather than an all-or-none phenomenon. In terms of measurement, the study suggests that a good test of PTA should include orientation questions, together with a reaction time measure, a visual recognition test and a speed of information processing measure. Most of the tests administered were good at distinguishing between brain-injured and nonbrain-injured people, although only two tests distinguished between the two brain-injured groups, i.e. those in PTA and those out of PTA. Almost all tests were good at monitoring recovery from PTA.

Criterion-based validity of an intracarotid amobarbital recognition-memory protocol

PURPOSE

We tested whether the behavioral components of an Intracarotid Amobarbital Protocol (IAP) had criterion validity. It was hypothesized that a recognition-memory test designed for intracarotid injections and used to predict the risk of global amnesia before an elective temporal lobectomy should also identify persons who are severely amnesic due to other neurologic causes. Divergent validity predicts that speech tasks would be unaffected by amnesia. Test-retest reliability also was measured.

METHODS

Fifteen persons with severe amnesia were administered four alternate forms of a yes/no recognition-memory protocol and a speech protocol. No drug injection occurred. Standardized neuropsychological tests were used to divide the amnesic group into those with Global Amnesia (i.e., retain no ongoing memories), Severe Amnesia (i.e., memory impaired), and Amnesia Plus (severe amnesia plus other neuropsychologic deficits).

RESULTS

Two persons with Global Amnesia obtained scores at or below chance (i.e., failed) on the memory protocol. Unexpectedly, 12 of 13 severely amnesic persons obtained near-perfect memory scores. Amnesia had no impact on the speech protocol. Pass/Fail outcomes were highly correlated across all four sets.

CONCLUSIONS

A four-item IAP memory protocol showed good reliability and criterion validity in identifying the rare condition of Global Amnesia, but it was insensitive to other disabling, severe amnesic disorders. This IAP memory protocol might have validity in predicting a postsurgical Global Amnesic disorder, but it did not identify and therefore could not predict other more common severe amnesic disorders.

Myotonic dystrophy and progressive cognitive decline: a common condition or two separate problems?

We report the case of NG, a 43-year old woman with myotonic dystrophy (MYD) who has shown a slow decline in both motor and cognitive abilities since her referral to us at age 32. MYD is an autosomal dominant disorder characterised by weakening and wasting of the muscles together with impaired muscle relaxation. Cognitive abilities are usually little affected in the adult onset form, although there is a high risk of cognitive impairment in those with childhood onset. Cognitive decline is also typically associated with maternal inheritance. NG, who was diagnosed with MYD at the age of 18, inherited it from her father. We report the decline in NG's cognitive abilities over 11 years of longitudinal assessment, and consider whether she is an atypical MYD patient or whether the MYD and cognitive decline are attributable to two separate pathological processes.

Localization of the intracellular activity domain of Pasteurella multocida toxin to the N terminus

We have shown that Pasteurella multocida toxin (PMT) directly causes transient activation of Gqalpha protein that is coupled to phosphatidylinositol-specific phospholipase Cbeta1 in Xenopus oocytes (B. A. Wilson, X. Zhu, M. Ho, and L. Lu, J. Biol. Chem. 272:1268-1275, 1997). We found that antibodies directed against an N-terminal peptide of PMT inhibited the toxin-induced response in Xenopus oocytes, but antibodies against a C-terminal peptide did not. To test whether the intracellular activity domain of PMT is localized to the N terminus, we conducted a deletion mutational analysis of the PMT protein, using the Xenopus oocyte system as a means of screening for toxin activity. Using PCR and conventional cloning techniques, we cloned from a toxinogenic strain of P. multocida the entire toxA gene, encoding the 1,285-amino-acid PMT protein, and expressed the recombinant toxin as a His-tagged fusion protein in Escherichia coli. We subsequently generated a series of N-terminal and C-terminal deletion mutants and expressed the His-tagged PMT fragments in E. coli. These proteins were screened for cytotoxic activity on cultured Vero cells and for intracellular activity in the Xenopus oocyte system. Only the full-length protein without the His tag exhibited activity on Vero cells. The full-length PMT and N-terminal fragments containing the first 500 residues elicited responses in oocytes, but the C-terminal 780 amino acid fragment did not. Our results confirm that the intracellular activity domain of PMT is localized to the N-terminal 500 amino acids of the protein and that the C terminus is required for entry into cells.