Association of CSF Biomarkers With Hippocampal-Dependent Memory in Preclinical Alzheimer Disease

OBJECTIVE

To determine whether memory tasks with demonstrated sensitivity to hippocampal function can detect variance related to preclinical Alzheimer disease (AD) biomarkers, we examined associations between performance in 3 memory tasks and CSF β-amyloid (Aβ)₄₂/Aβ₄₀ and phosopho-tau₁₈₁ (p-tau₁₈₁) in cognitively unimpaired older adults (CU).

METHODS

CU enrolled in the Stanford Aging and Memory Study (n = 153; age 68.78 ± 5.81 years; 94 female) completed a lumbar puncture and memory assessments. CSF Aβ₄₂, Aβ₄₀, and p-tau₁₈₁ were measured with the automated Lumipulse G system in a single-batch analysis. Episodic memory was assayed using a standardized delayed recall composite, paired associate (word-picture) cued recall, and a mnemonic discrimination task that involves discrimination between studied "target" objects, novel "foil" objects, and perceptually similar "lure" objects. Analyses examined cross-sectional relationships among memory performance, age, and CSF measures, controlling for sex and education.

RESULTS

Age and lower Aβ₄₂/Aβ₄₀ were independently associated with elevated p-tau₁₈₁. Age, Aβ₄₂/Aβ₄₀, and p-tau₁₈₁ were each associated with (1) poorer associative memory and (2) diminished improvement in mnemonic discrimination performance across levels of decreased task difficulty (i.e., target-lure similarity). P-tau mediated the effect of Aβ₄₂/Aβ₄₀ on memory. Relationships between CSF proteins and delayed recall were similar but nonsignificant. CSF Aβ₄₂ was not significantly associated with p-tau₁₈₁ or memory.

CONCLUSIONS

Tests designed to tax hippocampal function are sensitive to subtle individual differences in memory among CU and correlate with early AD-associated biomarker changes in CSF. These tests may offer utility for identifying CU with preclinical AD pathology.

Hippocampal and cortical mechanisms at retrieval explain variability in episodic remembering in older adults

Age-related episodic memory decline is characterized by striking heterogeneity across individuals. Hippocampal pattern completion is a fundamental process supporting episodic memory. Yet, the degree to which this mechanism is impaired with age, and contributes to variability in episodic memory, remains unclear. We combine univariate and multivariate analyses of fMRI data from a large cohort of cognitively normal older adults (N=100) to measure hippocampal activity and cortical reinstatement during retrieval of trial-unique associations. Trial-wise analyses revealed that (a) hippocampal activity scaled with reinstatement strength, (b) cortical reinstatement partially mediated the relationship between hippocampal activity and associative retrieval, (c) older age weakened cortical reinstatement and its relationship to memory behaviour. Moreover, individual differences in the strength of hippocampal activity and cortical reinstatement explained unique variance in performance across multiple assays of episodic memory. These results indicate that fMRI indices of hippocampal pattern completion explain within- and across-individual memory variability in older adults.

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder.

Altered Cortical Brain Structure and Increased Risk for Disease Seen Decades After Perinatal Exposure to Maternal Smoking: A Study of 9000 Adults in the UK Biobank

Secondhand smoke exposure is a major public health risk that is especially harmful to the developing brain, but it is unclear if early exposure affects brain structure during middle age and older adulthood. Here we analyzed brain MRI data from the UK Biobank in a population-based sample of individuals (ages 44-80) who were exposed (n = 2510) or unexposed (n = 6079) to smoking around birth. We used robust statistical models, including quantile regressions, to test the effect of perinatal smoke exposure (PSE) on cortical surface area (SA), thickness, and subcortical volumes. We hypothesized that PSE would be associated with cortical disruption in primary sensory areas compared to unexposed (PSE-) adults. After adjusting for multiple comparisons, SA was significantly lower in the pericalcarine (PCAL), inferior parietal (IPL), and regions of the temporal and frontal cortex of PSE+ adults; these abnormalities were associated with increased risk for several diseases, including circulatory and endocrine conditions. Sensitivity analyses conducted in a hold-out group of healthy participants (exposed, n = 109, unexposed, n = 315) replicated the effect of PSE on SA in the PCAL and IPL. Collectively our results show a negative, long term effect of PSE on sensory cortices that may increase risk for disease later in life.

Retrosplenial Cortical Neurons Encode Navigational Cues, Trajectories and Reward Locations During Goal Directed Navigation

The retrosplenial cortex (RSC) plays an important role in memory and spatial navigation. It shares functional similarities with the hippocampus, including the presence of place fields and lesion-induced impairments in spatial navigation, and the RSC is an important source of visual-spatial input to the hippocampus. Recently, the RSC has been the target of intense scrutiny among investigators of human memory and navigation. fMRI and lesion data suggest an RSC role in the ability to use landmarks to navigate to goal locations. However, no direct neurophysiological evidence of encoding navigational cues has been reported so the specific RSC contribution to spatial cognition has been uncertain. To examine this, we trained rats on a T-maze task in which the reward location was explicitly cued by a flashing light and we recorded RSC neurons as the rats learned. We found that RSC neurons rapidly encoded the light cue. Additionally, RSC neurons encoded the reward and its location, and they showed distinct firing patterns along the left and right trajectories to the goal. These responses may provide key information for goal-directed navigation, and the loss of these signals may underlie navigational impairments in subjects with RSC damage.

Pain and health-related quality of life in people with chronic leg ulcers

INTRODUCTION

Venous leg ulceration is associated with pain and poor health-related quality of life (HRQL). The purpose of this study was to identify demographic and clinical characteristics associated with pain and decreased HRQL in patients with active venous ulcers.

METHODS

Baseline data were combined from two trials that took place between 2001 and 2007 (n = 564). Pain was measured using the Numeric Pain Scale (NPS), and HRQL was measured using the Medical Outcomes Survey 12-item Short Form (SF-12), which generates a Physical (PCS) and Mental Component Summary (MCS). Analyses included logistic and linear regression (for pain and HRQL, respectively).

RESULTS

Mean age was 66.5 years; 47% were male. Median NPS score was 2.2 (out of 10) and mean PCS and MCS scores were 38.0 and 50.5, respectively (scores are standardized to a mean of 50 representing average HRQL). Younger age, living with others, and arthritis were associated with pain. Poorer PCS was associated with being female, venous/mixed ulcer etiology, larger ulcers, longer ulcer duration, cardiovascular disease, arthritis and higher pain intensity. Poorer MCS was associated with younger age, longer ulcer duration, comorbidity and higher pain intensity.

CONCLUSION

Research is needed to test strategies to reduce pain and possibly improve HRQL in high risk groups.

Pain and health-related quality of life in people with chronic leg ulcers

Introduction

Venous leg ulceration is associated with pain and poor health-related quality of life (HRQL). The purpose of this study was to identify demographic and clinical characteristics associated with pain and decreased HRQL in patients with active venous ulcers.

Methods

Baseline data were combined from two trials that took place between 2001 and 2007 (n = 564). Pain was measured using the Numeric Pain Scale (NPS), and HRQL was measured using the Medical Outcomes Survey 12-item Short Form (SF-12), which generates a Physical (PCS) and Mental Component Summary (MCS). Analyses included logistic and linear regression (for pain and HRQL, respectively).

Results

Mean age was 66.5 years; 47% were male. Median NPS score was 2.2 (out of 10) and mean PCS and MCS scores were 38.0 and 50.5, respectively (scores are standardized to a mean of 50 representing average HRQL). Younger age, living with others, and arthritis were associated with pain. Poorer PCS was associated with being female, venous/mixed ulcer etiology, larger ulcers, longer ulcer duration, cardiovascular disease, arthritis and higher pain intensity. Poorer MCS was associated with younger age, longer ulcer duration, comorbidity and higher pain intensity.

Conclusion

Research is needed to test strategies to reduce pain and possibly improve HRQL in high risk groups.

CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion

OBJECTIVE

Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs.

METHODS

We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression.

RESULTS

An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a well-behaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele.

CONCLUSIONS

Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors.

Guideline adaptation: an approach to enhance efficiency in guideline development and improve utilisation

BACKGROUND

Developing and updating high-quality guidelines requires substantial time and resources. To reduce duplication of effort and enhance efficiency, we developed a process for guideline adaptation and assessed initial perceptions of its feasibility and usefulness.

METHODS

Based on preliminary developments and empirical studies, a series of meetings with guideline experts were organised to define a process for guideline adaptation (ADAPTE) and to develop a manual and a toolkit made available on a website (http://www.adapte.org). Potential users, guideline developers and implementers, were invited to register and to complete a questionnaire evaluating their perception about the proposed process.

RESULTS

The ADAPTE process consists of three phases (set-up, adaptation, finalisation), 9 modules and 24 steps. The adaptation phase involves identifying specific clinical questions, searching for, retrieving and assessing available guidelines, and preparing the draft adapted guideline. Among 330 registered individuals (46 countries), 144 completed the questionnaire. A majority found the ADAPTE process clear (78%), comprehensive (69%) and feasible (60%), and the manual useful (79%). However, 21% found the ADAPTE process complex. 44% feared that they will not find appropriate and high-quality source guidelines.

DISCUSSION

A comprehensive framework for guideline adaptation has been developed to meet the challenges of timely guideline development and implementation. The ADAPTE process generated important interest among guideline developers and implementers. The majority perceived the ADAPTE process to be feasible, useful and leading to improved methodological rigour and guideline quality. However, some de novo development might be needed if no high quality guideline exists for a given topic.

Health Heritage© a web-based tool for the collection and assessment of family health history: initial user experience and analytic validity

A detailed family health history is currently the most potentially useful tool for diagnosis and risk assessment in clinical genetics. We developed and evaluated the usability and analytic validity of a patient-driven web-based family health history collection and analysis tool. Health Heritage(©) guides users through the collection of their family health history by relative, generates a pedigree, completes risk assessment, stratification, and recommendations for 89 conditions. We compared the performance of Health Heritage to that of Usual Care using a nonrandomized cohort trial of 109 volunteers. We contrasted the completeness and sensitivity of family health history collection and risk assessments derived from Health Heritage and Usual Care to those obtained by genetic counselors and genetic assessment teams. Nearly half (42%) of the Health Heritage participants reported discovery of health risks; 63% found the information easy to understand and 56% indicated it would change their health behavior. Health Heritage consistently outperformed Usual Care in the completeness and accuracy of family health history collection, identifying 60% of the elevated risk conditions specified by the genetic team versus 24% identified by Usual Care. Health Heritage also had greater sensitivity than Usual Care when comparing the identification of risks. These results suggest a strong role for automated family health history collection and risk assessment and underscore the potential of these data to serve as the foundation for comprehensive, cost-effective personalized genomic medicine.

Associations between chronic disease, age and physical and mental health status

This paper examines the associations between chronic disease, age, and physical and mental health-related quality of life (HRQOL), using data collected in 10 studies representing five chronic conditions. HRQOL was measured using the SF-36 or the shorter subset, SF-12. Physical Component Summary (PCS) and Mental Component Summary (MCS) scores were graphed by condition in age increments of 10 years, and compared to age- and sex-adjusted normative data. Linear regression models for the PCS and MCS were controlled for available confounders. The sample size of 2418 participants included 129 with renal failure, 366 with osteoarthritis (OA), 487 with heart failure, 1160 with chronic wound (leg ulcer) and 276 with multiple sclerosis (MS). For the PCS, there were large differences between the normative data and the mean scores of those with chronic diseases, but small differences for the MCS. Female gender and comorbid conditions were associated with poorer HRQOL; increased age was associated with poorer PCS and better MCS. This study provided additional evidence that, while physical function could be severely and negatively affected by both chronic disease and advanced age, mental health remained relatively high and stable.

A multifaceted intervention to improve treatment of osteoporosis in postmenopausal women with wrist fractures: a cluster randomized trial

In a cluster randomized trial, we evaluated the effect of a multifaceted intervention (directed at both patient and primary care physician) on the rates of testing and treatment of osteoporosis in postmenopausal women within six months of their wrist fracture. Compared to usual care, women in the intervention practices were three times more likely to receive bone mineral density testing and prescribed osteoporosis treatments.

INTRODUCTION

Postmenopausal women with wrist fractures are at increased risk of future fragility fractures, yet they frequently do not receive evaluation and treatment for osteoporosis. We set out to evaluate a multifaceted intervention designed to improve management of osteoporosis in older women with recent wrist fractures.

METHODS

Cluster randomized trial of 270 women cared for in 119 primary care practices. We recruited postmenopausal women with an acute wrist fracture from the emergency departments of hospitals in southeastern Ontario, Canada. Family practices were randomly assigned to either the intervention or usual care. The intervention consisted of a mailed reminder with a summary of treatment guidelines and letter sent to the primary care physician, in addition to an educational package and letter to the women. The primary outcome was the proportion of women prescribed osteoporosis therapy within 6 months of their fracture.

RESULTS

The mean age of women was 69(10.9) years. The intervention increased the proportion of women started on osteoporosis medications (28% vs. 10%) of controls, adjusted OR 3.45, 95% CI, 1.58-7.56, p = 0.002) and the proportion who had a bone mineral density (BMD) test (53.3% vs. 26%) of controls, OR 3.38, 95% CI, 1.83-6.26, p < 0.001). In addition to the intervention, having a female physician was a predictor of increased testing and treatment rates.

CONCLUSION

A multifaceted intervention significantly improved rates of osteoporosis treatment and BMD testing in postmenopausal women with wrist fractures.

Destruction of midbrain dopaminergic neurons by using immunotoxin to dopamine transporter

1. The ability to target specific neurons can be used to produce selective neural lesions and potentially to deliver therapeutically useful moieties for treatment of disease. In the present study, we sought to determine if a monoclonal antibody to the dopamine transporter (anti-DAT) could be used to target midbrain dopaminergic neurons. 2. The monoclonal antibody recognizes the second, large extracellular loop of DAT. The antibody was conjugated to the "ribosome-inactivating protein"; saporin, and stereotactically pressure microinjected into either the center of the striatum or the left lateral ventricle of adult, male Sprague-Dawley rats. 3. Local intrastriatal injections produced destruction of dopaminergic neurons in the ipsilateral substantia nigra consistent with suicide transport of the immunotoxin. Intraventricular injections (i.c.v.) produced significant loss of dopaminergic neurons in the substantia nigra and ventral tegmental area bilaterally without evident damage to any other aminergic structures such as the locus coeruleus and raphe nuclei. To confirm the anatomic findings, binding of [3-H]mazindol to DAT in the striatum and midbrain was assessed using densitometric analysis of autoradiograms. Anti-DAT-saporin injected i.c.v. at a dose of 21 microg, but not 8 microg, produced highly significant decreases in mazindol binding consistent with loss of the dopaminergic neurons. 4. These results show that anti-DAT can be used to target midbrain dopaminergic neurons and that anti-DAT-saporin may be useful for producing a lesion very similar to the naturally occurring neural degeneration seen in Parkinson's disease. Anti-DAT-saporin joins the growing list of neural lesioning agents based on targeted cytotoxins.

Pain in pure and mixed aetiology venous leg ulcers: a three-phase point prevalence study

OBJECTIVE

This study aimed to determine the point prevalence of venous leg ulcer pain over three seasons (autumn, winter and spring). It also collated profiles of individuals with venous ulceration and described the characteristics of people with and without venous leg ulcer pain.

METHOD

The study sample comprised 255 people with pure and mixed venous leg ulcers who were receiving care in a Canadian community leg ulcer service. Prevalence was determined by the number of individuals who had experienced pain in the past 24 hours. The profile of individuals was developed by analysing sociodemographic, circumstance-of-living, clinical and health-related quality-of-life data collected on admission to the leg ulcer service.

RESULTS

Over the three prevalence periods, the prevalence of pain for the total sample ranged from 48% to 54%. Prevalences at each of the study periods for individuals who had been receiving care for less than 13 weeks, and for the first measure of pain only, were almost identical, ranging from 48-59%. The mean pain-severity score was less than three (out of 10) in all three periods. Of the individuals with pain, 50% or more used analgesia and, of these, over 75% reported it was effective. The profile of participants with pain was similar to those without it, except that the former were significantly more likely to have osteoarthritis, a foot ulcer, to have been attending the leg service for a shorter time period and to have a lower SF-12 mental health component score.

CONCLUSION

These results demonstrate that leg ulcer management must include pain assessment and consideration of the factors that may be associated with pain. A large prospective repeated measures study is needed to increase understanding of the extent of pain, the use and efficacy of analgesia, and the factors that may be related to experiencing pain.

Increased neurosteroid sensitivity of hippocampal GABAA receptors during postnatal development

To investigate developmental changes in neurosteroid modulation of GABA(A) receptors, whole-cell currents were elicited by applying GABA with allopregnanolone or pregnenolone sulfate (PS) to dentate granule cells (DGCs), acutely isolated from 7-14-day-old and adult rats. GABA evoked larger currents from dentate granule cells acutely isolated from adult rats (adult DGCs) than from neonatal DGCs, due to increased efficacy (1662+/-267 pA in adult DGCs versus 1094+/-198 pA in neonatal DGCs, P=0.004), and current density (0.072+/-0.01 pA/microm(2) in neonatal rat DGCs to 0.178+/-0.02 pA/microm(2) in adult DGCs), but unchanged potency (EC(50) was 18.5+/-2 microm in adult DGCs, and 26.6+/-7.9 microm in neonatal DGCs, P=0.21). Allopregnanolone sensitivity of GABA(A) receptor currents increased during development due to an increased potency (21.1+/-4.7 nM in adult DGCs versus 94.6+/-9 nM in neonatal DGCs, P=0.0002). The potency and efficacy of PS inhibition of GABA(A) receptor currents were remained unchanged during development (13+/-6 microm and 13.2+/-5.9 microm, P=0.71 and 85.5%+/-3.5% and 83.6%+/-0.8%, P=0.29, respectively). To investigate possible mechanism of developmental changes in GABA(A) receptor properties, in situ hybridization for alpha1, alpha4 and gamma2 subunit mRNAs was performed in dentate gyrus of the two age groups. Qualitatively, alpha1 subunit mRNA was expressed at low levels in neonatal rats while it was well expressed in adult rats. The alpha4 and gamma2 subunits were well expressed in the dentate gyrus of adult and neonatal rats. Immunohistochemical staining for alpha1 subunit in hippocampal slices from neonatal and adult rats was examined under confocal laser scanning microscope. This demonstrated that cell bodies and dendrites of granule cells are moderately positive for the alpha1 staining in adult rats but weakly so in neonatal rats. Higher-magnification images demonstrate large number of clusters of alpha1-subunit in the cell bodies of dentate granule cells of adult rat but rare clusters in granule cells of neonatal rats. Maturation of GABA(A) receptors in DGCs is characterized by increased number of GABA(A) receptors that are more sensitive to endogenous neurosteroid allopregnanolone, which might be related to increased expression of alpha1 subunit.

The impacts of distance to hospital on families with a child with a chronic condition

Children with chronic conditions and their families face many similar challenges that can be stressful for the family including, daily caregiving activities, financial difficulties caused by unexpected expenses, and increased use of health services to treat and help manage the condition. Many of these families, in addition to facing daily caregiving responsibilities, must travel substantial distances to access some of the necessary aspects of their child's health care. In this study, the Burke et al. (1994-1996) data of repeatedly hospitalized children and their families are used to explore a geographical dimension of family impact, distance. Outcome measures from the Feetham Family Functioning Survey and the Questionnaire on Resources and Stress are analyzed using exploratory and multivariate analysis. Results show that distance to hospital plays a role in the two areas of family life regarding relationships within the immediate family, and issues surrounding the ability to maintain the child in the family home. The implications of the results for family, health care intervention, and government policies and guidelines are discussed.

Clinical practice guidelines: necessary but not sufficient for evidence-based patient education and counseling

While clinical practice guidelines provide direction for the management of specific diseases or particular clinical problems, there are major gaps between guidelines and their implementation. The purpose of this paper is to illustrate how an existing guideline can be used to develop an evidence-based patient education program. Congestive heart failure (CHF) represents a range of complex, chronic illnesses which offer little hope of cure yet require symptom management by health care providers, patients, and their families. Successful self-monitoring, self-care, and decision making are based on acquisition of appropriate knowledge and management skills. We describe a comprehensive teaching program in which the content was built on the clinical evidence from the Agency for Health Care Policy and Research recommendations for CHF, and the implementation process was built on adult education evidence, adapted to health issues and patient learning challenges.

Early changes in neuropeptide mRNA expression in the striatum following reserpine treatment

Chronic dopamine depletion produces neurochemical changes within the striatum as well as enhanced behavioral and metabolic responses to dopamine agonists. Changes in striatal neuropeptides have been consistently described, including increased expression of preproenkephalin mRNA and decreased expression of preprotachykinin and prodynorphin mRNA. Acute dopamine depletion following treatment with reserpine also produces enhanced behavioral and metabolic responses to agonist treatment which develop rapidly. In the present study, we used in situ hybridization histochemistry to investigate whether acute neurochemical changes occur following reserpine treatment. We evaluated neuropeptide mRNA expression in the striatum and nucleus accumbens at several time points from 6 to 120 h following single doses of reserpine and AMPT. The aim of these studies was to determine if changes in neuropeptide mRNA expression occur following acute dopamine depletion and whether such changes are specific to the striatum. Changes in striatal neuropeptide mRNA expression developed rapidly. Preproenkephalin mRNA expression by striatopallidal neurons was unchanged at 48 h, but increased by 44% at 120 h. Preprotachykinin mRNA expression in striatonigral neurons was increased at 6 h and then fell, with a maximal decrease of 45% at 48 h and partial recovery by 120 h. Prodynorphin mRNA expression was unchanged. Expression of preproenkephalin and preprotachykinin mRNA was also examined in subregions of the striatum and the nucleus accumbens. Expression of preproenkephalin mRNA was uniform in the striatum and higher in the core than the shell of the nucleus accumbens. Preprotachykinin mRNA expression in the striatum was higher in the lateral quadrants and was higher in the shell than in the core of the nucleus accumbens. The changes in neuropeptide mRNA following treatment with reserpine were only found in the striatum. These data provide further evidence for early alterations in neuronal function in the striatum following acute dopamine depletion and suggest that neuropeptide expression by striatonigral neurons may be more rapidly regulated in response to changes in dopamine levels.

Parents' perceptions of chronic illness trajectories

The notion of a small, generic set of chronic illness trajectories that can be independent of specific medical diagnoses, though controversial, has some theoretical, clinical, and qualitative research support. The purpose of this study was to quantitatively describe trajectories among parents of children with a chronic condition. It was hypothesized that factor analysis would confirm 3 trajectories similar to those in the qualitative literature and that parents' perceptions of their child's trajectory would differ significantly from medically based perceptions. A total of 140 parents provided data on their perceptions of the past, present, and future course of the condition of their repeatedly hospitalized child. Fourteen time-related items from the Coping Health Inventory for Parents Questionnaire on Resources and Stress and the Parenting Stress Index were analyzed. Pre- and post-hospitalization factor analyses extracted the same 8 items to construct 3 trajectories: Life Threatening; Declining; and Stable, Optimistic. The views of approximately one third of the parents differed from medically based classifications. Type of nursing care had no bearing on the perceptions of the parents.

Canadian oncologists and clinical practice guidelines: a national survey of attitudes and reported use. Provincial Lung Disease Site Group of Cancer Care Ontario

PURPOSE

To determine (1) Canadian oncologists' attitudes toward practice guidelines, (2) oncologists' self-reported use of practice guidelines and, (3) physicians' characteristics and attitudes associated with self-reported use of practice guidelines.

PARTICIPANTS AND METHODS

A cross-sectional, self-administered postal survey was administered to Canadian oncologists. Main outcome measures were level of agreement with 8 descriptive statements about guidelines, score on the attitudinal scale of the guideline of Tunis et al., and physicians' stated use of guideline. chi(2) and logistic regression procedures were used to explore the relationship between physician characteristics and use of guidelines.

RESULTS

Over 80% of respondents agreed that they were good educational tools, convenient sources of advice, intended to improve quality of care; over 40% agreed that they were unbiased syntheses of expert opinion. Conversely, 42, 26, 20 and 16% felt they were intended to cut costs, were oversimplified cookbook medicine, were too rigid to apply to individual patients, and a challenge to physicians' authority, respectively. Forty-one percent reported using practice guidelines routinely or most of the time. Use was associated with positive attitudes about guidelines, receiving medical school training abroad and being a radiation oncologist.

CONCLUSION

Canadian oncologists were quite positive about practice guidelines and reported using them frequently. Our results suggest that use of guidelines by oncologists may be related to attitudes about guidelines in general, specialty within oncology and country of medical school training.

Huntington's Disease

Huntington's disease is a neurodegenerative disorder inherited in an autosomal dominant fashion that results in involuntary movements, psychiatric symptoms, and cognitive dysfunction. The illness typically begins in midlife and progresses over 15 to 20 years, producing increasing disability. The diagnosis of Huntington's disease in an individual has implications for family members as well, whose at-risk status may be altered by the diagnosis. Genetic counseling and information about alternative approaches (eg, clinical diagnosis, DNA banking) should be provided and consent obtained before DNA testing in a symptomatic patient. Genetic counseling is essential for predictive testing in asymptomatic at-risk individuals. Although disease-modifying therapy is not yet available, a multidisciplinary approach to both pharmacologic and nonpharmacologic management can improve the motor and psychiatric symptoms of the illness and enhance function and quality of life for patients and their families. There have been few rigorous trials of treatments for Huntington's disease. The medications discussed in this article have been empirically found to be useful in the management of specific symptoms. Therapy for the movement disorder should focus on those symptoms that specifically limit function. The potential contribution of medication side effects to disability should be periodically reassessed and therapy adjusted as the disease progresses. Psychiatric symptoms are a substantial source of morbidity in this disorder and should be actively treated because they are often quite responsive to appropriate therapy. Both the motor and the psychiatric symptoms can be modified by environmental as well as pharmacologic strategies. Ongoing assessment of the need for adjunctive therapies by means of physical, occupational, and speech therapy is an important component of management, and social work intervention is often necessary to assist with the practical difficulties faced by patients and caregivers. Voluntary organizations are an important source of information and support for professionals caring for patients with Huntington's disease as well as for patients and their families.

Characterization of cybrid cell lines containing mtDNA from Huntington's disease patients

Electron transport chain (ETC) dysfunction may arise from mitochondrial genetic, nuclear genetic, or toxic etiologies. Cytoplasmic hybrid (cybrid) systems can help distinguish between these possibilities by facilitating expression of suspect mitochondrial DNA (mtDNA) within a nuclear and environmentally controlled context. Perpetuation of ETC dysfunction in cybrids is consistent with an mtDNA pathogenesis while defect correction is not. We previously used cybrids to screen sporadic Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis patients for mtDNA mutation with positive results. To further address the fidelity of these experiments, we created and characterized cybrids expressing mtDNA from persons with Huntington's disease (HD), an autosomal dominant, nuclear DNA-determined disorder in which mitochondrial ETC functioning is abnormal. On ETC, oxidative stress, and calcium homeostasis assays HD cybrid lines were indistinguishable from control cybrid lines. These data support the use of the cybrid technique for mtDNA mutation screening in candidate diseases.

Evidence-based pressure-ulcer practice: the Ottawa model of research use

Developing evidence-based nursing practice among diverse health-care settings is a particular challenge in the face of current health-care restructuring. This paper describes application of the Ottawa Model of Research Use (OMRU) to increase evidence-based practice across 3 health-care settings during a time of multiple restructuring changes. The initiative was part of a provincial demonstration project to develop centers of nursing excellence with a view to improving continuity of care across the health continuum. Three Ottawa health-care agencies formed one of 4 participating sites in the Province-Wide Nursing Project (PWNP), a 3-year initiative funded by the Ontario Ministry of Health. The goal of the Ottawa-Carleton site was to increase evidence-based decision-making with a focus on pressure ulcers. The barriers and supports encountered, and the strategies used, in striving to meet this goal in a community-care, tertiary-care, and long-term-care setting are described. Multiple research transfer approaches were used, with an emphasis on education. Implementor consensus and achievements of the project support the OMRU's utility as a guide to implementing research findings in these health-care settings.

Assessment of stressors in families with a child who has a chronic condition

Nurses working with families who have children with a chronic condition are aware of the complexity of the tasks and stresses they deal with daily. The challenge is to uncover the issues that require the most immediate intervention while noting others for the future. This article describes the development of a comprehensive guide for experienced nurses to identify a family's stressors and tasks. It can be used with a broad range of chronic diagnoses. Nurses who have used the guide report that it helped them to focus and plan timely, appropriate nursing interventions with these families. It also serves as a record and planning tool for documenting issues that may become priorities for future interventions.

Stressors in families with a child with a chronic condition: an analysis of qualitative studies and a framework

This article presents a comprehensive, research-based, clinically useable framework of stressors and tasks for families with a child with a chronic condition. Terms such as stressors, tasks, challenges, concerns, and problems are commonly used to describe the struggles and triumphs of these families. Their unique and changing nature has complicated comprehensive description. The steps in the early development of the Burke Stressors and Tasks Framework for Families with a Child with a Chronic Condition, and its clinical uses, are briefly described. The final step in the development of the Framework is discussed in more detail. This was a "meta-analysis" of qualitative research findings that confirmed the components of the Framework. Conclusions are drawn for subsequent research steps and clinical uses of the Framework.

Early morning dystonia in Parkinson's disease

We interviewed 383 patients with PD regarding disease onset and medication history and evaluated them using the Unified Parkinson's Disease Rating Scale. Sixteen percent of the sample reported the occurrence of early morning dystonia (EMD). Patients with EMD had been taking levodopa for a longer time, were taking higher daily levodopa doses, demonstrated more disability in carrying out their activities of daily living, exhibited dystonia more often before initiation of levodopa treatment, and experienced more peak-dose and diphasic dyskinesias with levodopa therapy.

Stress-point intervention for parents of children hospitalized with chronic conditions

Stress-point intervention by Nurses (SPIN) is a research-based intervention that can be used to assist families whose child has a chronic condition and is repeatedly hospitalized. The intervention addresses attendant family stressors, tasks, and concerns. SPIN incorporates parent-nurse contact before admission, during hospitalization, and after discharge. A nurse assists each family to develop their unique set of coping strategies, which are shaped by the family's own concerns and resources and the nurse's expertise. The effectiveness of SPIN has been tested in two intervention studies, one based in the community and another based in ambulatory clinics. Both studies found that families receiving SPIN interventions had better parental coping and family functioning, and there was less developmental regression in the child after hospitalization. SPIN can be used by nurses having experience working with families and children. A self-directed learning program assists with understanding of theoretical and practical aspects of SPIN.

Hospital to home evidence-based education for CHF

Congestive heart failure (CHF) is a significant health problem in Canadian adults and continues to be a leading cause of morbidity and mortality. It has been cited as the most rapidly growing category of cardiovascular disorder. There is little likelihood that patients experiencing CHF will leave the health care system until death. Typically, they move between health care sectors, being repeatedly admitted and discharged from each. In our system today, where institutional and community sectors are separately organized, separately funded and poorly linked at the point of service delivery, these patients are at high risk for discontinuity of care.

Getting to know oncology inpatients and their families: a continuous quality improvement approach

Given the overall magnitude of cancer, a climate of stretched health care resources, and the political activism of cancer survivors and families, it is becoming increasingly clear that local service providers need to assess and reassess the care they provide. A qualitative design was used to seek the patient and family's perspectives on whether or not their needs were being met while in hospital. Direct feedback from a convenience sample of 19 oncology patients and families was elicited through a semi-structured interview. Qualitative data analysis revealed eight important aspects of care for oncology patients and their families. These included: communication between patients and caregivers, caregiver availability and concerns about health care cutbacks, coordination and continuity of care, physical care and comfort, psychosocial care, caregiver sensitivity, caregiver competence, and the physical environment of the hospital. Challenges faced by individuals and their families affected by cancer are highlighted as they navigate through our health care system. Respondents provide positive reinforcement for use of appropriate interventions by caregivers, while clearly outlining areas needing improvement.

Clinical correlates of sleep benefit in Parkinson's disease

The phenomenon of sleep benefit, a period of lessened disability or feeling "on" upon awakening from sleep in the morning, has received scant attention in the literature on Parkinson's disease. We interviewed 162 consecutive patients regarding disease onset, medication history, and symptoms, evaluated them using the Unified Parkinson's Disease Rating Scale, and assessed them as to the presence or absence of sleep benefit. Thirty-three percent reported experiencing sleep benefit. Compared with patients not having sleep benefit, patients with sleep benefit tended to be younger at disease onset, have longer disease duration, take higher total daily doses of levodopa, have longer duration of levodopa treatment, and exhibit less cognitive and physical disability. The findings of this study suggest that sleep benefit is a common phenomenon that may be anticipated in a subgroup of patients with Parkinson's disease. The mechanisms underlying sleep benefit do not appear to be simple and may be multifactorial. Clinicians need to be aware of the authenticity of patients' reports of sleep benefit and consider the existence of this phenomenon when prescribing or adjusting patients' medication schedules.

Maternal inheritance in Parkinson's disease

To evaluate possible matrilineal factors in the inheritance of Parkinson's disease, we prospectively identified families in which a parent and multiple siblings had Parkinson's disease. In each of the 5 families identified, the affected parent was the mother (p < 0.03). The age at onset in the offspring generation in these 5 families was younger than the age at onset in the parental generation (p < 0.001). In addition, the age at onset in all patients with an affected mother (n = 18) was younger than the age at onset in the affected mothers (p < 0.001). No difference was found between the age at onset in patients with an affected father (n = 14) and the age at onset in the affected fathers. These results are consistent with a role for inherited abnormalities of mitochondrial DNA in the pathogenesis of at least some cases of Parkinson's disease.

Expression of m1 and m4 muscarinic receptor mRNA in the striatum following a selective lesion of striatonigral neurons

Cholinergic stimulation has opposing effects on striatopallidal and striatonigral neurons. Most striatal projection neurons express m1 muscarinic receptor mRNA with m4 mRNA found in 40-50%. Expression of m4 mRNA is found in most preprotachykinin neurons but only a subset of preproenkephalin neurons, suggesting preferential localization of m4 receptors to striatonigral neurons. A volkensin lesion of striatonigral neurons reduced striatal m4 mRNA by 63% and m1 mRNA by only 18%, suggesting that preferential expression of m4 receptors by striatonigral neurons may contribute to their differential response.

A D1 dopamine agonist stimulates acetylcholine release from dissociated striatal cholinergic neurons

We tested the hypothesis that a D1 dopamine agonist could stimulate acetylcholine release directly from striatal cholinergic neurons. A suspension of viable dissociated striatal cells was made enzymatically and mechanically from normal adult male rats. The heterogeneous suspension was incubated in [3H]choline to allow synthesis of [3H]acetylcholine selectively by cholinergic neurons. Fractional [3H]acetylcholine release from the cholinergic cells in the suspension was recorded during continuous dynamic perifusion. The D1 agonist, 50 microM (+/-) SKF 38393, increased the basal rate of release from the cholinergic cells by 50% and the action was inhibited by the D1 antagonist, SKF 83566. Stimulation of [3H]acetylcholine secretion was recorded as low as 500 nM SKF 38393. The (S, -) SKF 38393 stereoisomer was significantly less effective than the (R, +) isomer in stimulating release. The D1-mediated stimulation of acetylcholine secretion was abolished in a low-calcium environment that also inhibited basal release. The data suggest that striatal cholinergic cells express D1 receptors functionally coupled to the regulation of acetylcholine release. These D1 actions in the absence of synaptic circuitry imply that such circuitry is not required in situ. In vivo however, indirectly mediated D1 actions and those of other transmitters may modify the manifestations of this direct cholinergic stimulation.

Practice guidelines for the prediction and prevention of pressure ulcers: evaluating the evidence

Clinical practice guidelines for the prediction and prevention of pressure ulcer (Agency for Health Care Policy and Research [AHCPR], 1992) were evaluated in a Canadian, university-affiliated, acute care hospital. Through a prospective study, the prevalence of pressure ulcers was determined, and pressure ulcer incidence was tracked to evaluate the accuracy of the Braden Scale for risk assessment. The prevalence rate for stage II or greater pressure ulcers was 13.6%; the rate was 29.7% when stage I (persistent redness) was included. In evaluating the Braden Scale's accuracy in predicting risk, the findings from this study were less favorable than previous reports. The total Braden score that appeared to have the best balance of sensitivity (67%) and specificity (66%) was 19. Several factors should be considered: The scale was implemented and tested hospitalwide with a wide range of patient diagnoses, age, and severity; the study was a cross-section of an existing population; and the levels of nursing care and type of staff vary between units ranging from critical to long-term care. This study highlights the need for individual settings to evaluate the AHCPR Guidelines for the Prediction and Prevention of Pressure Ulcers.

Acetylcholine release from dissociated striatal cells

To study the regulation of striatal acetylcholine (ACH) release, adult male rat striata were dissociated and incubated with 3H-choline to synthesize 3H-ACH. Fractional 3H-ACH efflux per min during continuous perifusion was: (1) tightly regulated; (2) dependent on calcium influx; (3) stimulated by 10 mM K+ and 1 mM glutamate; and (4) comparable to ACH release detected by HPLC. Thus, acutely dissociated striata exhibit calcium-sensitive, voltage-dependent secretion of 3H-ACH and direct receptor-mediated stimulation of release through the glutamate receptor family. This new approach toward cholinergic secretory physiology will help clarify complex striatal circuitry.

Acute dopamine depletion potentiates independent stimulatory and inhibitory D1 DA receptor-mediated control of striatal acetylcholine release in vitro

Fractional release of [3H]ACh was evaluated under basal and evoked conditions in striatal slices from normal and acutely dopamine-depleted adult rats for the influence of D1- and D2-DA receptor agonists. The D1 ligand had no effect on normal slices but DA depletion unmasked two independent but simultaneous supersensitive responses: augmentation of K(+)-evoked and inhibition of glutamate-evoked release. The D2 ligand inhibited evoked release in normal slices and this effect was not potentiated. This is a new cholinergic model of acute D1 receptor supersensitivity.

Opioid peptide expression in models of chronic temporal lobe epilepsy

Expression of the opioid peptides dynorphin and enkephalin is altered within the first 24 h after acutely induced seizures in certain experimental models of epilepsy. Using in situ hybridization, we examined the expression of prodynorphin and preproenkephalin messenger RNA acutely following induction of kindling with recurrent seizures and in two models of chronic temporal lobe epilepsy: (i) rats fully kindled with rapidly recurring hippocampal seizures; and (ii) rats surviving after self-sustaining limbic status epilepticus induced with focal electrical stimulation of the hippocampus. In naive animals, a ventral-dorsal gradient was identified in the expression of both prodynorphin and preproenkephalin messenger RNA in the dentate gyrus and expression of prodynorphin message was demonstrated for the first time in the ventral portion of cornu Ammonis regio superior. After stimulation producing rapidly recurring hippocampal seizures, acute decreases in prodynorphin messenger RNA were seen in the dentate gyrus and cornu Ammonis regio superior at 24 h after the last seizure. In contrast, increases in preproenkephalin messenger RNA expression were seen acutely in the dentate gyrus, with a decrease seen in the entorhinal cortex. The change in prodynorphin message expression in cornu Ammonis regio superior persisted in kindled animals that were studied after one month seizure-free period. There were no changes in preproenkephalin message in kindled animals studied after the one month seizure-free interval. No statistically significant changes were found for either prodynorphin or preproenkephalin message in the post-self-sustaining limbic status epilepticus group at one month following induced seizures. Acute changes in peptide expression may contribute to increased excitation in the dentate gyrus during induction of kindling, while the chronic change identified in cornu Ammonis regio superior may contribute directly to persistently increased excitability in this region.

Prolonged survival in carcinomatous meningitis associated with breast cancer

We describe a patient who survived for more than 7 years after the diagnosis of meningeal carcinomatosis associated with breast cancer. Meningeal carcinomatosis occurs in 1% to 5% of patients with breast cancer. The median survival ranges from 3 to 7 months, but most reports include a small number of patients who survive considerably longer, with up to 11% surviving more than 1 year. Early diagnosis, aggressive treatment of neurologic involvement, limited systemic tumor burden, and varied rates of progression are factors that may relate to extended duration of survival in these patients with breast cancer. Our patient, with a hormonally responsive adenocarcinoma of the breast and without systemic metastases, illustrates that meningeal carcinomatosis, like other forms of breast cancer metastasis, can run an indolent course. In such patients the delayed sequelae of therapy for metastasis to the central nervous system can profoundly influence the course of the illness.

Differential localization of A2a adenosine receptor mRNA with D1 and D2 dopamine receptor mRNA in striatal output pathways following a selective lesion of striatonigral neurons

We have used the suicide transport agent volkensin to produce selective lesions of striatonigral neurons. By in situ hybridization histochemistry unilateral volkensin injections in the substantia nigra decreased the number of D1 receptor mRNA-expressing neurons in the ipsilateral striatum but did not change the number of D2 receptor and A2a adenosine receptor mRNA-expressing neurons. These findings confirm that striatonigral neurons express D1 receptors and suggest that D2-A2a receptor expressing neurons are predominantly localized to other neuronal populations within the striatum.

A selective lesion of striatonigral neurons decreases presynaptic binding of [3H]hemicholinium-3 to striatal interneurons

We have used the suicide transport agent, volkensin, to produce selective lesions of striatal efferent neurons projecting to the substantia nigra in the rat. In order to evaluate potential trans-synaptic effects, we examined cholinergic interneurons intrinsic to the striatum following destruction of striatonigral projection neurons by nigral injection of volkensin. There was no change in the number of large interneurons identified either by Nissl stain or by immunocytochemistry for choline acetyltransferase, indicating that volkensin was not directly toxic to this group of neurons. However, [3H]hemicholinium-3 binding to the choline re-uptake site on the presynaptic cholinergic terminals decreased. No change in [3H]hemicholinium-3 binding was seen after destruction of dopaminergic afferents with 6-hydroxydopamine. Striatonigral afferents to the cholinergic interneurons contain substance P which has been shown to stimulate acetylcholine release. The decrease in [3H]hemicholinium-3 binding may reflect loss of this afferent input. However, striatonigral neurons are an efferent target of the cholinergic interneuron as well, and a presynaptic effect due to loss of target neurons also may contribute.

Differential effects of suicide transport lesions of the striatonigral or striatopallidal pathways on subsets of striatal neurons

In the basal ganglia, centrally active suicide transport agents produce apparently selective lesions of the striatopallidal and striatonigral pathways based on receptor binding and neuropeptide mRNA studies. In the present study we sought to determine the selectivity of suicide transport lesions for specific subsets of striatal neurons. Using immunohistochemical methods, the neostriata of adult rats were examined 10 days after an injection of volkensin into the substantia nigra or an injection of OX7-saporin into the globus pallidus. Ricin, a suicide transport agent active in the peripheral but not the central nervous system, was injected into each target as a control. Adjacent sections were processed for (1) Nissl stain to assess neuronal density, both overall and for large interneurons, (2) NADPH-diaphorase (NADPH-d) histochemistry, to mark medium-sized aspiny interneurons, (3) enkephalin immunocytochemistry, to label striatopallidal neurons, or (4) substance P immunocytochemistry, to label striatonigral neurons. Ricin injections produced no change in the densities of these subsets of striatal cells. In animals receiving volkensin or OX7-saporin injections, analyses of Nissl material revealed that the striata ipsilateral to the toxin injections appeared normal and did not exhibit shrinkage or gliosis; however, a quantitation analysis revealed a moderate decrease in cell density (12-16% loss, P < 0.01). The densities of both large and NADPH-d-containing striatal interneurons were unchanged after lesions in either target. Following nigral injections with volkensin, the density of striatal substance P-labeled cells decreased (26% loss, P < 0.01), while the density of enkephalin-labeled cells did not decrease significantly (11% decrease, P > 0.1). After pallidal injections with OX7-saporin, the density of striatal enkephalin-labeled cells decreased (20% loss, P < 0.01), while that of substance P-labeled cells remained unchanged. These data show that nigral volkensin and pallidal OX7-saporin injections differentially lesion striatonigral and striatopallidal projection neurons and spare striatal interneurons. This study provides further evidence for the selectivity, specificity, and utility of suicide transport agents to study brain structure and function.

Phenytoin and dyskinesias: a report of two cases and review of the literature

Dyskinesia is a recognized but uncommon side-effect of treatment with phenytoin. Two additional cases of dyskinesia during treatment with phenytoin are described; both had radiographically documented thalamic infarctions. The reported experience to date with movement disorders induced by phenytoin is reviewed and the clinical features summarized. The available experimental evidence addressing the mechanism underlying this side effect is discussed.