A placental model of SARS-CoV-2 infection reveals ACE2-dependent susceptibility and differentiation impairment in syncytiotrophoblasts

SARS-CoV-2 infection causes COVID-19. Several clinical reports have linked COVID-19 during pregnancy to negative birth outcomes and placentitis. However, the pathophysiological mechanisms underpinning SARS-CoV-2 infection during placentation and early pregnancy are not clear. Here, to shed light on this, we used induced trophoblast stem cells to generate an in vitro early placenta infection model. We identified that syncytiotrophoblasts could be infected through angiotensin-converting enzyme 2 (ACE2). Using a co-culture model of vertical transmission, we confirmed the ability of the virus to infect syncytiotrophoblasts through a previous endometrial cell infection. We further demonstrated transcriptional changes in infected syncytiotrophoblasts that led to impairment of cellular processes, reduced secretion of HCG hormone and morphological changes vital for syncytiotrophoblast function. Furthermore, different antibody strategies and antiviral drugs restore these impairments. In summary, we have established a scalable and tractable platform to study early placental cell types and highlighted its use in studying strategies to protect the placenta.

Reward insensitivity is associated with dopaminergic deficit in rapid eye movement sleep behaviour disorder

Idiopathic rapid eye movement sleep behaviour disorder (iRBD) has now been established as an important marker of the prodromal stage of Parkinson's disease and related synucleinopathies. However, although dopamine transporter single photon emission computed tomography (SPECT) has been used to demonstrate the presence of nigro-striatal deficit in iRBD, quantifiable correlates of this are currently lacking. Sensitivity to rewarding stimuli is reduced in some people with Parkinson's disease, potentially contributing to aspects of the neuropsychiatric phenotype in these individuals. Furthermore, a role for dopaminergic degeneration is suggested by the fact that reward insensitivity can be improved by dopaminergic medications. Patients with iRBD present a unique opportunity to study the relationship between reward sensitivity and early dopaminergic deficit in the unmedicated state. Here, we investigate whether a non-invasive, objective measure of reward sensitivity might be a marker of dopaminergic status in prodromal Parkinson's disease by comparing with SPECT/CT measurement of dopaminergic loss in the basal ganglia. Striatal dopaminergic deficits in iRBD are associated with progression to Parkinsonian disorders. Therefore, identification of a clinically measurable correlate of this degenerative process might provide a basis for the development of novel risk stratification tools. Using a recently developed incentivized eye-tracking task, we quantified reward sensitivity in a cohort of 41 patients with iRBD and compared this with data from 40 patients with Parkinson's disease and 41 healthy controls. Patients with iRBD also underwent neuroimaging with dopamine transporter SPECT/CT. Overall, reward sensitivity, indexed by pupillary response to monetary incentives, was reduced in iRBD cases compared with controls and was not significantly different to that in patients with Parkinson's disease. However, in iRBD patients with normal dopamine transporter SPECT/CT imaging, reward sensitivity was not significantly different from healthy controls. Across all iRBD cases, a positive association was observed between reward sensitivity and dopaminergic SPECT/CT signal in the putamen. These findings demonstrate a direct relationship between dopaminergic deficit and reward sensitivity in patients with iRBD and suggest that measurement of pupillary responses could be of value in models of risk stratification and disease progression in these individuals.

134 Apathy in cerebrovascular small vessel disease is characterised by distinct white matter tract changes

Introduction

Clinical apathy is a poorly understood neuropsychiatric syndrome characterised by a sig- nificant decrease in goal-directed, motivated behaviour. It occurs in ~30% of patients with cerebrovas- cular small vessel disease (SVD). With the aim of improving our mechanistic understanding of apathy, we conducted a multimodal investigation combining validated behavioural paradigms and magnetic resonance imaging (MRI) techniques.

Methods

83 patients with MRI evidence of SVD were recruited from the Oxford Vascular Study (OXVASC) and Oxford neurology clinics. They were investigated using a novel effort-based decision making task and the Apathy Evaluation Scale (AES). Structural and diffusion weighted MRI was conducted to measure white matter lesion load (WMLL) and tract integrity, indexed by Fractional anisotropy (FA).

Results

Patients with apathy demonstrated a significant reduction in motivated behaviour and were sig- nificantly less incentivised by low levels of reward. Diffusion weighted imaging demonstrated that apathy was characterised by focal changes to limbic association tracts, including the uncinate fasciculus and cingulum bundle, as well as fronto-striatal white matter tracts. Importantly, global measures of disease severity did not independently associate with apathy.

Discussion

Reduced incentivisation by low reward characterised apathy in SVD, as previously reported in Parkinson’s disease, suggesting a common mechanism underlying apathy across neurological diseases. The association of apathy with focal white matter tract changes is consistent with disruption to key frontal and fronto-striatal circuits which have been previously implicated in effort-based decision-making for rewards.

youssuf.saleh@ndcn.ox.ac.uk

Vividness of visual imagery questionnaire scores and their relationship to visual short-term memory performance

Mechanisms underlying visual imagery, the ability to create vivid mental representations of a scene in the absence of sensory input, remain to be fully understood. Some previous studies have proposed that visual imagery might be related to visual short-term memory (STM), with a common mechanism involving retention of visual information over short periods of time. Other observations have shown a strong relationship between visual imagery and functional activity in the hippocampus and primary visual cortex, both regions also associated with visual STM. Here we examined the relationship of visual imagery to STM and hippocampal and primary visual cortex volumes, first in a large sample of healthy people across a large age range (N = 229 behavioural data; N = 56 MRI data in older participants) and then in patients with Alzheimer's disease and Parkinson's disease (N = 19 in each group compared to 19 age-matched healthy controls). We used a variant of the "What was where?" visual object-location binding task to assess the quality of remembered information over short delays. In healthy people, no evidence of a relationship between the vividness of visual imagery and any visual STM performance parameter was found. However, there was a significant positive correlation between visual imagery and the volumes of the hippocampus and primary visual cortex. Although visual STM performance was significantly impaired in patients with Alzheimer's disease, their vividness of visual imagery scores were comparable to those of age-matched elderly controls and patients with Parkinson's disease. Despite hippocampal volumes also being reduced in Alzheimer's patients, there appeared to be no impact on their self-reported visual imagery. In conclusion, visual imagery was not significantly related to visual STM performance, either in healthy controls or Alzheimer's or Parkinson's disease but it was related to hippocampal and visual cortex volume in healthy people.

Assessment of apathy in neurological patients using the Apathy Motivation Index caregiver version

Apathy is a common, disabling neuropsychiatric syndrome that occurs across many brain disorders and may be associated with diminished motivation in behavioural, cognitive, emotional and social domains. Assessment is complicated by the variability of symptoms across apathy domains and self‐report from patients, which can be misleading due to their lack of insight. Independent evaluation by clinicians also has limitations though if it has to be performed with limited time. Caregiver reports are a viable alternative, but current assessments for them either do not distinguish between different apathy domains or are interview‐based and take long to administer. In this study, we developed a brief caregiver questionnaire version of the recently developed Apathy Motivation Index (AMI), which is a self‐report tool. We confirmed three apathy factors in this new caregiver measure (AMI‐CG) that were also present in the AMI: Behavioural Activation, Emotional Sensitivity and Social Motivation. Furthermore, we validated the scores against more extensive caregiver interviews using the established Lillle apathy rating scale as well as patient self‐reports of apathy, measures of depression, anhedonia, cognition, activities of daily living and caregiver burden across four different neurological conditions: Parkinson's disease, Alzheimer's disease, subjective cognitive impairment and limbic encephalitis. The AMI‐CG showed good internal reliability, external validity and diagnostic accuracy. It also uncovered cases of social apathy overlooked by traditional instruments. Crucially, patients who under‐rated their apathy compared to informants were more likely to have difficulties performing everyday activities and to be a greater burden to caregivers. The findings provide evidence for a multidimensional conceptualization of apathy and an instrument for efficient detection of apathy based on caregiver reports for use in clinical practice.

Ageing is associated with disrupted reinforcement learning whilst learning to help others is preserved

Reinforcement learning is a fundamental mechanism displayed by many species. However, adaptive behaviour depends not only on learning about actions and outcomes that affect ourselves, but also those that affect others. Using computational reinforcement learning models, we tested whether young (age 18-36) and older (age 60-80, total n = 152) adults learn to gain rewards for themselves, another person (prosocial), or neither individual (control). Detailed model comparison showed that a model with separate learning rates for each recipient best explained behaviour. Young adults learned faster when their actions benefitted themselves, compared to others. Compared to young adults, older adults showed reduced self-relevant learning rates but preserved prosocial learning. Moreover, levels of subclinical self-reported psychopathic traits (including lack of concern for others) were lower in older adults and the core affective-interpersonal component of this measure negatively correlated with prosocial learning. These findings suggest learning to benefit others is preserved across the lifespan with implications for reinforcement learning and theories of healthy ageing.

Reduced decision bias and more rational decision making following ventromedial prefrontal cortex damage

Human decisions are susceptible to biases, but establishing causal roles of brain areas has proved to be difficult. Here we studied decision biases in 17 people with unilateral medial prefrontal cortex damage and a rare patient with bilateral ventromedial prefrontal cortex (vmPFC) lesions. Participants learned to choose which of two options was most likely to win, and then bet money on the outcome. Thus, good performance required not only selecting the best option, but also the amount to bet. Healthy people were biased by their previous bet, as well as by the unchosen option's value. Unilateral medial prefrontal lesions reduced these biases, leading to more rational decisions. Bilateral vmPFC lesions resulted in more strategic betting, again with less bias from the previous trial, paradoxically improving performance overall. Together, the results suggest that vmPFC normally imposes contextual biases, which in healthy people may actually be suboptimal in some situations.

Aging Increases Prosocial Motivation for Effort

Social cohesion relies on prosociality in increasingly aging populations. Helping other people requires effort, yet how willing people are to exert effort to benefit themselves and others, and whether such behaviors shift across the life span, is poorly understood. Using computational modeling, we tested the willingness of 95 younger adults (18-36 years old) and 92 older adults (55-84 years old) to put physical effort into self- and other-benefiting acts. Participants chose whether to work and exert force (30%-70% of maximum grip strength) for rewards (2-10 credits) accrued for themselves or, prosocially, for another. Younger adults were somewhat selfish, choosing to work more at higher effort levels for themselves, and exerted less force in prosocial work. Strikingly, compared with younger adults, older people were more willing to put in effort for others and exerted equal force for themselves and others. Increased prosociality in older people has important implications for human behavior and societal structure.

Apathy in small vessel cerebrovascular disease is associated with deficits in effort-based decision making

Patients with small vessel cerebrovascular disease frequently suffer from apathy, a debilitating neuropsychiatric syndrome, the underlying mechanisms of which remain to be established. Here we investigated the hypothesis that apathy is associated with disrupted decision making in effort-based decision making, and that these alterations are associated with abnormalities in the white matter network connecting brain regions that underpin such decisions. Eighty-two patients with MRI evidence of small vessel disease were assessed using a behavioural paradigm as well as diffusion weighted MRI. The decision-making task involved accepting or rejecting monetary rewards in return for performing different levels of physical effort (hand grip force). Choice data and reaction times were integrated into a drift diffusion model that framed decisions to accept or reject offers as stochastic processes approaching a decision boundary with a particular drift rate. Tract-based spatial statistics were used to assess the relationship between white matter tract integrity and apathy, while accounting for depression. Overall, patients with apathy accepted significantly fewer offers on this decision-making task. Notably, while apathetic patients were less responsive to low rewards, they were also significantly averse to investing in high effort. Significant reductions in white matter integrity were observed to be specifically related to apathy, but not to depression. These included pathways connecting brain regions previously implicated in effort-based decision making in healthy people. The drift rate to decision parameter was significantly associated with both apathy and altered white matter tracts, suggesting that both brain and behavioural changes in apathy are associated with this single parameter. On the other hand, depression was associated with an increase in the decision boundary, consistent with an increase in the amount of evidence required prior to making a decision. These findings demonstrate altered effort-based decision making for reward in apathy, and also highlight dissociable mechanisms underlying apathy and depression in small vessel disease. They provide clear potential brain and behavioural targets for future therapeutic interventions, as well as modelling parameters that can be used to measure the effects of treatment at the behavioural level.

Reward sensitivity and action in Parkinson's disease patients with and without apathy

Clinical apathy results in dysfunction of goal directed behaviour, a key component of which is the initiation of action. Previous work has suggested that blunting of reward sensitivity is an important mechanism underlying apathy. However, an additional component might be impoverished initiation of action itself. This study aims to investigate the link between motivation and motor output and its association with apathy and dopamine. An oculomotor task that measures pupillary and saccadic response to monetary incentives was used to assess reward sensitivity, first in 23 young and 18 elderly controls, and then in 22 patients with Parkinson's disease tested ON and OFF dopaminergic medication. To distinguish between pupillary responses to anticipated reward alone versus responses associated with motor preparation, a saccadic 'go/no-go' task was performed. Half of the trials required a saccade to be initiated to receive a reward and in the remaining trials no action was required but reward was still obtained. No significant difference in pupil response was demonstrated between the two conditions in all groups tested, suggesting pupillary responses to rewards are not contingent upon motor preparation in Parkinson's disease. Being ON or OFF dopamine did not influence this response either. Previous work demonstrated associations between apathy and pupillary reward insensitivity in Parkinson's disease. Here we observed this effect only when an action was required to receive a reward, and only in the ON state. These findings suggest that apathy in Parkinson's disease is linked to reduced reward sensitivity and that this is most prominently observed when actions have to be initiated to rewarding goals, with the effect modulated by being ON dopaminergic medication. OFF medication, there was no such strong relationship, and similarly in the 'no-go' conditions, either ON or OFF dopaminergic drugs. The results provide preliminary data which suggest that apathy in Parkinson's disease is associated with a reduction in reward sensitivity and this is most evident when associated with initiation of goal directed actions in the presence of adequate dopamine.

The relationship between apathy and impulsivity in large population samples

Apathy and impulsivity are debilitating conditions associated with many neuropsychiatric conditions, and expressed to variable degrees in healthy people. While some theories suggest that they lie at different ends of a continuum, others suggest their possible co-existence. Surprisingly little is known, however, about their empirical association in the general population. Here, gathering data from six large studies (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n = 3755$$\end{document}n=3755), we investigated the relationship between measures of apathy and impulsivity in young adults. The questionnaires included commonly used self-assessment tools—Apathy Evaluation Scale, Barratt Impulsiveness Scale (BIS-11) and UPPS-P Scale—as well as a more recent addition, the Apathy Motivation Index (AMI). Remarkably, across datasets and assessment tools, global measures of apathy and impulsivity correlated positively. However, analysis of sub-scale scores revealed a more complex relationship. Although most dimensions correlated positively with one another, there were two important exceptions revealed using the AMI scale. Social apathy was mostly negatively correlated with impulsive behaviour, and emotional apathy was orthogonal to all other sub-domains. These results suggest that at a global level, apathy and impulsivity do not exist at distinct ends of a continuum. Instead, paradoxically, they most often co-exist in young adults. Processes underlying social and emotional apathy, however, appear to be different and dissociable from behavioural apathy and impulsivity.

Different patterns of short-term memory deficit in Alzheimer's disease, Parkinson's disease and subjective cognitive impairment

It has recently been proposed that short-term memory (STM) binding deficits might be an important feature of Alzheimer's disease (AD), providing a potential avenue for earlier detection of this disorder. By contrast, work in Parkinson's disease (PD), using different tasks, has suggested that the STM impairment in this condition is characterised by increased random guessing, possibly due to fluctuating attention. In the present study, to establish whether a misbinding impairment is present in sporadic late-onset AD (LOAD) and increased guessing is a feature of PD, we compared the performance of these patient groups to two control populations: healthy age-matched controls and individuals with subjective cognitive impairment (SCI) with comparable recruitment history as patients. All participants performed a sensitive task of STM that required high resolution retention of object-location bindings. This paradigm also enabled us to explore the underlying sources of error contributing to impaired STM in patients with LOAD and PD using computational modelling of response error. Patients with LOAD performed significantly worse than other groups on this task. Importantly their impaired memory was associated with increased misbinding errors. This was in contrast to patients with PD who made significantly more guessing responses. These findings therefore provide additional support for the presence of two doubly dissociable signatures of STM deficit in AD and PD, with binding impairment in AD and increased random guessing characterising the STM deficit in PD. The task used to measure memory precision here provides an easy-to-administer assessment of STM that is sensitive to the different types of deficit in AD and PD and hence has the potential to inform clinical practice.

Binding deficits in visual short-term memory in patients with temporal lobe lobectomy

Classical views of the medial temporal lobe (MTL) have established that it plays a crucial role in long-term memory (LTM). Here we demonstrate, in a sample of patients who have undergone anterior temporal lobectomy for the treatment of pharmacoresistant epilepsy, that the MTL additionally plays a specific, causal role in short-term memory (STM). Patients (n=22) and age-matched healthy control participants (n=26) performed a STM task with a sensitive continuous report measure. This paradigm allowed us to examine recall memory for object identity, location and object-location binding, independently on a trial-by-trial basis. Our findings point to a specific involvement of MTL in object-location binding, but, crucially, not retention of either object identity or location. Therefore the MTL appears to perform a specific computation: binding disparate features that belong to a memory. These results echo findings from previous studies, which have identified a role for the MTL in relational binding for LTM, and support the proposal that MTL regions perform such a function for both STM and LTM, independent of the retention duration. Furthermore, these findings and the methodology employed here may provide a simple, sensitive and clinically valuable means to test memory dysfunuction in MTL disorders.

Differential impact of behavioral, social, and emotional apathy on Parkinson's disease

Apathy is highly prevalent in Parkinson's disease. New findings suggest the syndrome is multifaceted. Here, we investigate whether all aspects of apathy are equally affected in Parkinson's disease and whether different dimensions of apathy were associated with depression and anhedonia. On the Apathy Motivation Index, while behavioral apathy and social apathy were elevated, emotional motivation was relatively preserved in Parkinson's disease, although a few patients did show impaired emotional sensitivity. Behavioral and social, but not emotional, apathy was associated with depression and anhedonia. These findings suggest aspects of motivation can be selectively impaired in Parkinson's disease and may have implications for guiding treatment.

Grandparents of children with cancer: a controlled comparison of perceived family functioning

PURPOSE

Grandparents can be profoundly emotionally affected when a grandchild is diagnosed with cancer. They also often provide invaluable support for the family (e.g., caring for the sick child and/or siblings). Multigenerational family functioning may therefore change. Limited research has assessed grandparents' perspectives after their grandchild is diagnosed with cancer. In this study, we aimed to (1) assess differences in perceived family functioning among grandparents of a child with cancer and grandparents of healthy children and (2) assess the cancer-specific and demographic factors related to perceived family functioning in grandparents of a grandchild with cancer.

PROCEDURE

Grandparents of a child with cancer (n = 89) and grandparents of healthy children (n = 133) completed the general functioning, communication, and problem-solving scales of the Family Assessment Device. We used multilevel models with a random intercept to detect (1) between-group differences and (2) identify factors related to perceived family functioning among grandparents with a grandchild with cancer.

RESULTS

Grandparents with a grandchild with cancer reported poorer family functioning than grandparents with healthy grandchildren. Among the grandparents with a grandchild with cancer, impairments in family functioning were correlated with fewer years since diagnosis, providing care to their sick grandchild and/or siblings and living far away from the sick grandchild.

CONCLUSIONS

The detrimental impact of childhood cancer likely extends beyond the immediate family members. Including grandparents in interventions-beginning at diagnosis-to reduce distress and increase cohesion for families of a child with cancer is warranted, particularly for grandparents who provide care to their sick grandchild or siblings.

Apathy in rapid eye movement sleep behaviour disorder is common and under-recognized

BACKGROUND AND PURPOSE

Apathy is an important neuropsychiatric feature of Parkinson's disease (PD), which often emerges before the onset of motor symptoms. Patients with rapid eye movement sleep behaviour disorder (RBD) have a high probability of developing PD in future. Neuropsychiatric problems are common in RBD, but apathy has not previously been detailed in this key prodromal population.

METHODS

Eighty-eight patients with polysomnographically proven RBD, 65 patients with PD and 33 controls were assessed for apathy using the Lille Apathy Rating Scale. Cognition and depression were also quantified. The sensitivity of the Unified Parkinson's Disease Rating Scale screening questions for apathy and depression was calculated.

RESULTS

A total of 46% of patients with RBD were apathetic, compared with 31% of patients with PD in our sample. Most patients with RBD with depression were apathetic but more than half of apathetic patients were not depressed. The sensitivity of the single Unified Parkinson's Disease Rating Scale screening question was only 33% for mild apathy and 50% for severe apathy.

CONCLUSIONS

Apathy is common in RBD and is underestimated by a single self-report question. Recognition of apathy as a distinct neuropsychiatric feature in RBD could aid targeted treatment interventions and might contribute to the understanding of prodromal PD.

Distinct Motivational Effects of Contingent and Noncontingent Rewards

When rewards are available, people expend more energy, increasing their motivational vigor. In theory, incentives might drive behavior for two distinct reasons: First, they increase expected reward; second, they increase the difference in subjective value between successful and unsuccessful performance, which increases contingency—the degree to which action determines outcome. Previous studies of motivational vigor have never compared these directly. Here, we indexed motivational vigor by measuring the speed of eye movements toward a target after participants heard a cue indicating how outcomes would be determined. Eye movements were faster when the cue indicated that monetary rewards would be contingent on performance than when the cue indicated that rewards would be random. But even when the cue indicated that a reward was guaranteed regardless of speed, movement was still faster than when no reward was available. Motivation by contingent and certain rewards was uncorrelated across individuals, which suggests that there are two separable, independent components of motivation. Contingent motivation generated autonomic arousal, and unlike noncontingent motivation, was effective with penalties as well as rewards.

Grandparents of children with cancer: Quality of life, medication and hospitalizations

BACKGROUND

Grandparents can play a crucial role of providing emotional and practical support for families facing childhood cancer. Yet, many have their own healthcare needs. This controlled study systematically assesses the impact of childhood cancer on grandparents' quality of life (QOL). Our objective was to compare QOL in grandparents of children with and without cancer and to identify factors associated with grandparents' QOL.

PROCEDURE

Grandparents (N = 222) completed two patient-reported outcome (PRO) measures assessing QOL: EQ-5D-5L and WHOQOL-BREF. Secondary endpoints included sleep, medications and hospitalizations. We used independent samples t-tests and multivariate linear regression to assess between-group differences and identify predictors.

RESULTS

Grandparents of children with cancer (n = 89) reported significantly worse QOL than controls (n = 133) [mean WHOQOL-BREF score: 75.6 (SD = 17.6) vs. 81.5 (15.6), P = 0.007; mean EQ-5D-5L index value: 0.777 (0.20) vs. 0.874 (0.14), P < 0.001)]. They also reported more problems with anxiety and depression (47.2 vs. 21.8%, P < 0.001) and pain (64.8 vs. 49.6%, P = 0.031). Grandparents of children with cancer reported taking longer to fall asleep [mean: 30.4 min (55.6) vs. 18.2 (20.2), P = 0.011] and taking more medications in the last 4 weeks [mean: 2.9 (SD = 3.8) vs. 1.8 (SD = 2.3), P = 0.012]. Hospitalizations were comparable across groups. Grandmothers, those living in urban locations, and retired/unemployed grandparents experienced reduced QOL.

CONCLUSIONS

Grandparents are significantly affected by childhood cancer. The impact appears across many domains of life and results in meaningful QOL differences. Given that four or more individuals may be affected per child, and that grandparent well-being can influence the whole family, interventions targeting at-risk grandparents are needed.

An in-vacuo optical levitation trap for high-intensity laser interaction experiments with isolated microtargets

We report on the design, construction, and characterisation of a new class of in-vacuo optical levitation trap optimised for use in high-intensity, high-energy laser interaction experiments. The system uses a focused, vertically propagating continuous wave laser beam to capture and manipulate micro-targets by photon momentum transfer at much longer working distances than commonly used by optical tweezer systems. A high speed (10 kHz) optical imaging and signal acquisition system was implemented for tracking the levitated droplets position and dynamic behaviour under atmospheric and vacuum conditions, with ±5 μm spatial resolution. Optical trapping of 10 ± 4 μm oil droplets in vacuum was demonstrated, over timescales of >1 h at extended distances of ∼40 mm from the final focusing optic. The stability of the levitated droplet was such that it would stay in alignment with a ∼7 μm irradiating beam focal spot for up to 5 min without the need for re-adjustment. The performance of the trap was assessed in a series of high-intensity (10(17) W cm(-2)) laser experiments that measured the X-ray source size and inferred free-electron temperature of a single isolated droplet target, along with a measurement of the emitted radio-frequency pulse. These initial tests demonstrated the use of optically levitated microdroplets as a robust target platform for further high-intensity laser interaction and point source studies.

Brain haemosiderin in older people: pathological evidence for an ischaemic origin of magnetic resonance imaging (MRI) microbleeds

Introduction

Magnetic resonance imaging (MRI) cerebral microbleeds (CMB) arise from ferromagnetic haemosiderin iron assumed to derive from extravasation of erythrocytes. Light microscopy of ageing brain frequently reveals foci of haemosiderin from single crystalloids to larger, predominantly perivascular, aggregates. The pathological and radiological relationship between these findings is not resolved.

Methods

Haemosiderin deposition and vascular pathology in the putamen were quantified in 200 brains donated to the population-representative Medical Research Council Cognitive Function and Ageing Study. Molecular markers of gliosis and tissue integrity were assessed by immunohistochemistry in brains with highest (n = 20) and lowest (n = 20) levels of putamen haemosiderin. The association between haemosiderin counts and degenerative and vascular brain pathology, clinical data, and the haemochromatosis (HFE) gene H63D genotype were analysed. The frequency of MRI CMB in 10 cases with highest and lowest burden of putamen haemosiderin, was compared using post mortem 3T MRI.

Results

Greater putamen haemosiderin was significantly associated with putaminal indices of small vessel ischaemia (microinfarcts, P < 0.05; arteriolosclerosis, P < 0.05; perivascular attenuation, P < 0.001) and with lacunes in any brain region (P < 0.023) but not large vessel disease, or whole brain measures of neurodegenerative pathology. Higher levels of putamen haemosiderin correlated with more CMB (P < 0.003).

Conclusions

The MRI-CMB concept should take account of brain iron homeostasis, and small vessel ischaemic change in later life, rather than only as a marker for minor episodes of cerebrovascular extravasation. These data are of clinical relevance, suggesting that basal ganglia MRI microbleeds may be a surrogate for ischaemic small vessel disease rather than exclusively a haemorrhagic diathesis.

Gestational trophoblastic disease in the Asian population of Northern England and North Wales

OBJECTIVE

To determine the incidence and trends of gestational trophoblastic disease in the Asian population of Northern England and North Wales.A prospective observational study.

SETTING

Trophoblastic Screening and Treatment Centre, Weston Park Hospital.

POPULATION

A total of 3660 women registered with gestational trophoblastic disease between 1991 and 1999.

MAIN OUTCOME MEASURES

1. The incidence of gestational trophoblastic disease in Asian and non-Asian population. 2. Trend in incidence over study period.

RESULTS

Three hundred and twenty-two Asian patients were registered. The incidence of gestational trophoblastic disease in the northern part of England and Wales averaged 1 per 714 live births. The incidence of gestational trophoblastic disease in the Asian population was 1.95 times higher than in the non-Asian population (1 per 387 live births vs 1 per 752 live births). There was an excess of molar pregnancies in the extreme maternal age groups; the incidence in these women was twice as high as in the whole reproductive cohort. The ratio of partial to complete hydatidiform mole increased from 0.9 in the lower age to 2.6 in the older age group. There appeared to be a slowly rising trend in the incidence of gestational trophoblastic disease; the increase was higher in the Asian than in the non-Asian population. The ratio of partial to complete moles increased with age in both populations.

CONCLUSION

Asian women are at increased risk of having molar pregnancies. Molar pregnancies are more common at the extremes of reproductive age. The setting up of regional or national registration centres has helped to provide more accurate estimates of the true incidence of the disease.

Effects of disability compensation on participation in and outcomes of vocational rehabilitation

OBJECTIVE

The authors sought to determine the relationship between receipt of disability compensation and participants' success in a vocational rehabilitation program.

METHODS

Administrative data for 22,515 individuals who participated in the Veterans Health Administration compensated work therapy program between 1993 and 1998 were analyzed. Six dependent variables were compared between participants who were receiving disability compensation and those who were not: duration of participation in compensated work therapy, number of hours worked per week, mean hourly earnings, total income from compensated work therapy, dropout rate, and competitive employment status at discharge. Regression equations were determined for each dependent variable to assess associations with the degree of disability, the amount of disability compensation, and the type of compensation program.

RESULTS

Participants who were receiving disability benefits worked fewer hours in compensated work therapy each week, earned less income, had a higher dropout rate, and were less likely to be competitively employed at discharge. The amount of compensation and the type of program were modestly but significantly associated with participation in compensated work therapy and with outcome.

CONCLUSIONS

Unintended effects of disability compensation programs discourage full participation in vocational rehabilitation and result in poorer rehabilitation outcomes.

Muscle learning therapy--efficacy of a biofeedback based protocol in treating work-related upper extremity disorders

Work-related upper extremity disorders (WRUEDs) continue to present significant treatment and financial challenges to providers, employers, and insurers. This retrospective study reviews outcomes for 309 subjects who, between 1995 and 1999, were referred through the workers' compensation system for treatment of computer keyboard- and mouse-related WRUED injuries. The mean length of time from the recorded date of injury to the date of intake was 12.9 months. Subjects were offered a 12-visit course in muscle learning therapy (MLT). MLT is an operant conditioning program which uses surface electromyography (sEMG) to train injured workers to control their muscles during work activities. Patient response to therapy was obtained by a therapist-administered questionnaire during Visit 8 of 12. A group of 309 subjects, who had failed to respond to a previous course of therapy (typically physical therapy), reported significant improvements of pain in the neck, thorax, and upper extremities. Ninety six percent reported that they felt "more in control," 86% reported feeling "better overall," and 81% reported either "working the same and feeling better" or "working and accomplishing more." This study provides preliminary support for this approach and provides justification for controlled clinical trials in the future.

An international feasibility study of parental decision making in pediatric oncology

PURPOSE/OBJECTIVES

To describe parental decision making about treatment options for children with cancer and determine the feasibility of a similar but larger international study.

DESIGN

Exploratory.

SETTINGS

A pediatric catastrophic illness research hospital in the United States and children's hospitals in Australia and Hong Kong.

SAMPLE

A convenience sample of 43 parents (5 fathers and 38 mothers ages 23-59 years).

METHODS

Six open-ended interview questions posed to parents during private individual interviews. Content analysis techniques were used.

MAIN RESEARCH VARIABLES

Parental perceptions of (a) factors considered in the decision-making process, (b) behaviors of healthcare professionals that affected the process, and (c) satisfaction with the process. Feasibility of a larger study was estimated by considering ease of access to parents, number of refusals to participate, understanding of the interview questions, and level of interest at each setting.

FINDINGS

Access to parents was possible at all sites. Refusal to participate was reported only at the U.S. site. Certain factors (e.g., getting information from the healthcare team, trusting staff) were important to all parents considering end-of-life decisions. Site-specific factors included considering alternative therapies (at the Australian site) and strengthening faith (at the U.S. site).

CONCLUSIONS

A larger international study of parental decision making is feasible. Sufficient similarities in parental decision making exist across these sites to justify future efforts to identify universal decision-making factors that, in conjunction with site-specific differences, could be helpful in developing guidelines for healthcare professionals who assist parents in making treatment-related decisions for a sick child.

Cisplatin ototoxicity, increased DPOAE amplitudes, and magnesium deficiency. Distortion product otoacoustic emissions

Outer hair cell (OHC) metabolism is blocked by cisplatin. Concurrent changes in the renal handling of magnesium occur because of the damage cisplatin causes to the renal proximal tubule cells within the thick ascending loop of Henle. Although there is no evidence of cisplatin within the OHCs, there are significant levels of intracellular calcium, the antagonist to magnesium at the cell membrane. The OHC motile response is dependent on intracellular calcium. When the calcium current is suppressed by an antagonist, the extracellular OHC microphonic potential decreases. Magnesium deficiency is known to produce hyperexcitability within the central nervous system, including fatal audiogenic seizures. In addition, increases in the amplitude of the auditory brainstem response wave V occur with aminoglycoside therapy and magnesium deficiency. This paper illustrates the amplitude growth of distortion product otoacoustic emissions in two patients treated with cisplatin and explores the possible underlying reasons why this may be related to magnesium metabolism.

How healthcare professionals contribute to hope in patients with cancer

PURPOSE/OBJECTIVES

To explore whether healthcare professionals influence the level of hope in patients with cancer and, if so, how they influence their hope.

DESIGN

Descriptive, qualitative design.

SETTING

An adult hematology/oncology unit in the upper midwestern United States.

SAMPLE

Thirty-two men and women receiving active or supportive treatment or palliative care for cancer.

METHODS

Semistructured interviews conducted in the participants' hospital rooms. Ten investigators and two consultants transcribed and analyzed the interview data using content analysis. They identified themes and subthemes that described healthcare professionals' roles.

MAIN RESEARCH VARIABLES

Healthcare professionals' contributions to hope as described by patients with cancer.

FINDINGS

Healthcare professionals positively and negatively influenced hope in this sample. Hope was facilitated by being present, giving information, and demonstrating caring behaviors. Negative influences on hope primarily concerned the way in which healthcare professionals gave information.

CONCLUSION

Healthcare professionals do influence patients' perceptions of their hope. Although most nursing actions are hope enhancing, nurses can reduce a patient's sense of hope if information provided or attitude toward the patient is insensitive or disrespectful.

IMPLICATIONS FOR NURSING PRACTICE

Nurses can increase patients' hope by being present, taking time to talk, and being helpful. They must provide information and answer questions in a compassionate, positive, honest, and respectful manner. Caring behaviors such as thoughtful gestures, showing warmth and genuineness, and being friendly and polite also increase patients' hope.

Australian midwives: leaders in lactation consultancy

Midwives all over Australia are furthering their breastfeeding knowledge and skills, to lead the world in lactation support. The certification exam conducted by the International Board of Lactation Consultant Examiners has played a central role in this extraordinary revolution by setting competency standards, motivating the acquisition of specialist skills, and opening up career opportunities. However, it is the consumers, the mothers and babies, who are the principal beneficiaries.

DNA vaccines for bacterial infections

DNA vaccines are an exciting development in vaccine technology which may have a special role in preventing viral infections and as 'theracines' for cancer. Their use in preventing bacterial infections has, by comparison, been less well documented. While it is unlikely that traditional, highly successful and cheap vaccines for diseases such as diphtheria will be replaced by DNA vaccines, naked DNA may be particularly appropriate for preventing bacterial infections where cytotoxic T cells confer protection, or where a Th1 type T cell response mediates resistance. For example, DNA vaccines containing different mycobacterial antigens have been shown to inhibit overt infections by Mycobacterium tuberculosis in rodent models. The use of DNA vaccines in bacterial infections may be complicated by fundamental differences between prokaryotic and eukaryotic genes and gene products, including mRNA stability, codon bias, secondary structures surrounding native start sequences and glycosylation. These problems can be solved by re-synthesis of bacterial genes to produce 'new' sequences which are more highly expressed by eukaryotic cells.

Nutrition and cancer: educating the public through a health fair

Minnesota has a high incidence of dietary-associated cancer, including colorectal, breast, and prostate. To increase public awareness of cancer risks and health benefits of dietary behaviors, the Metro Minnesota Chapter of the Oncology Nursing Society (ONS) participated in a public education health fair. Supported by a Special Project Funding Grant from the ONS, 42 chapter members assisted more than 700 Metro area residents at seven locations to assess and improve their diet according to the American Cancer Society (ACS) guidelines. To evaluate the effectiveness of the project, a postcard survey was sent to 200 (29%) names randomly drawn from raffle entries. Seventy-five surveys were returned (38%). Ninety-five percent found the assessment helpful in evaluating their diet, and 80% made dietary changes in the two weeks following the health fair. Results indicate that nurses should continue to educate the public about the relationship between diet and cancer. Recommendations for further consideration include assessment of long-term effects of the health fair education format and provision of a brochure about ONS. Benefits included community education and ONS member participation in a chapter activity.

Determination of thiocyanate in plasma and saliva without deproteinisation and its validation as a smoking parameter

A simple photometric procedure was developed for the determination of thiocyanate (SCN-) in plasma and saliva without deproteinisation or dialysis. Fe(III) ions form a red coloured complex with SCN- with a maximum absorbance at 460 nm. Mercury(II) nitrate is used to run a sample blank. A manual and an automated version (COBAS BIO) of the method is described. The method is linear up to 5000 mumol/l SCN-. The CV of the between-run precision is 2.8-8% for the manual and 2.6-6.6% for the automated method. The SCN- plasma concentration was 21-134 mumol/l in nonsmokers and 44-260 mumol/l in smokers. In mixed saliva, the concentration is much higher than in plasma: 1.57-5.5 mumol/l in smokers and 0.79-3.9 mumol/l in nonsmokers. Plasma, but not oral fluid SCN-, is a valuable parameter for studying smoking habits in population surveys. However, its use is limited. In our experience only heavy smokers can be distinguished from nonsmokers.

Homogeneity of potassium chloride in small volume intravenous containers

The purpose of this investigation was to determine whether potassium chloride as an additive is distributed homogeneously throughout small volume parenteral solutions and whether the pattern of electrolyte distribution is identical for two types of delivery systems. The effect of purposeful mixing after addition of potassium chloride was also studied. Thirty-one registered nurses prepared two supplementary intravenous solutions consisting of 10mEq potassium chloride in 50ml of 5% dextrose solution. One solution was prepared in a soft polyvinyl chloride minibag (Viaflex, Baxter-Travenol), the other in a semirigid plastic burette (Buretrol, Baxter-Travenol). The solutions were discharged through a volumetric pump (IMED) and four aliquots were taken at regular intervals. Samples were chemically analyzed by flame photometry to determine the potassium concentration in each solution layer of the container. For each container type, there were significant differences in the potassium concentrations among the layers of solution. The pattern of distribution also differed significantly between the two containers. The strata in the minibag showed smaller variations in potassium concentration than did corresponding layers in the burette. Some single sample concentrations from burettes exceeded the expected concentration of 200mEq/L by 105mEq. Nurses manipulated the two types of containers differently. Thirty of 31 minibags were mechanically mixed, but only 11 of 31 burettes were treated in this way. When the effect of mixing was considered, solutions in mixed containers were essentially no different from those not agitated after addition of the electrolyte.

Intravenous leiomyomatosis with cardiac extension

A woman with intravenous leiomyomatosis experienced syncope 7 years after a total abdominal hysterectomy and oophorectomy for a uterine fibroid. The workup revealed a tumor that extended from the iliac veins to the right ventricle. It was totally removed under cardiopulmonary bypass. One year later, the patient was found to be asymptomatic and without evidence of tumor recurrence.