Polypharmacy and Potential Drug-Drug Interactions in Home-Dwelling Older People - A Cross-Sectional Study

Background

Risks associated with polypharmacy and drug-drug interactions represent a challenge in drug treatment, especially in older adults. The aim of the present study was to assess the use of prescription and non-prescription drugs and the frequency of potential drug-drug interactions in home-dwelling older individuals.

Methods

A cross-sectional study design was applied. Data were collected during preventive home visits among individuals aged ≥75 in three separate communities of Western Norway. A questionnaire, which was filled out by the individual, their next-of-kin, and the nurse performing the home visit was used for the collection of demographic and clinical data (age, sex, medication use, diagnoses, need of assistance with drug administration). Potential drug-drug interactions were identified electronically by IBM Micromedex Drug Interaction Checking. Point prevalence of potential drug-drug interactions and polypharmacy (≥5 drugs) were calculated. Binary logistic regression analyses were performed to assess factors potentially associated with polypharmacy or potential drug-drug interactions.

Results

Among the 233 individuals (mean age 78±3 years, 46% male) included in the study, 43% used ≥5 drugs, 3.4% ≥10 drugs, while 4.3% used no drugs. In 54% of the 197 individuals using two or more drugs, at least one potential drug-drug interaction was detected. Low-dose aspirin and simvastatin were most frequently involved in potential drug-drug interactions. In total, 25% of the individuals reported current use of drugs sold over the counter of which more than 95% were analgesic drugs. Potential drug-drug interactions involving ibuprofen were identified in nine of 11 (82%) individuals using over-the-counter ibuprofen.

Conclusion

The study revealed a high prevalence of polypharmacy and potential drug-drug interactions with both prescription and non-prescription drugs in older home-dwelling individuals. Close monitoring of the patients at risk of drug-drug interactions, and increased awareness of the potential of over-the-counter drugs to cause drug-drug interactions, is needed.

Brain changes in Alzheimer's disease patients with implanted encapsulated cells releasing nerve growth factor

New therapies with disease-modifying effects are urgently needed for treating Alzheimer's disease (AD). Nerve growth factor (NGF) protein has demonstrated regenerative and neuroprotective effects on basal forebrain cholinergic neurons in animal studies. In addition, AD patients treated with NGF have previously shown improved cognition, EEG activity, nicotinic binding, and glucose metabolism. However, no study to date has analyzed brain atrophy in patients treated with NGF producing cells. In this study we present MRI results of the first clinical trial in patients with AD using encapsulated NGF biodelivery to the basal forebrain. Six AD patients received the treatment during twelve months. Patients were grouped as responders and non-responders according to their twelve-months change in MMSE. Normative values were created from 131 AD patients from ADNI, selecting 36 age- and MMSE-matched patients for interpreting the longitudinal changes in MMSE and brain atrophy. Results at baseline indicated that responders showed better clinical status and less pathological levels of cerebrospinal fluid (CSF) Aβ1-42. However, they showed more brain atrophy, and neuronal degeneration as evidenced by higher CSF levels of T-tau and neurofilaments. At follow-up, responders showed less brain shrinkage and better progression in the clinical variables and CSF biomarkers. Noteworthy, two responders showed less brain shrinkage than the normative ADNI group. These results together with previous evidence supports the idea that encapsulated biodelivery of NGF might have the potential to become a new treatment strategy for AD with both symptomatic and disease-modifying effects.

Long-term beneficial effects of adrenal medullary autografts supported by nerve growth factor in Parkinson's disease

Parkinson's disease has been the object of several therapeutic strategies based upon replacement of the degenerating dopaminergic neurons. Adrenal medullary transplants were tried initially, because of the biochemical relationship between chromaffin cells of the medulla and dopaminergic neurons of the substantia nigra. Compared to transplant of fetal neurons, autologous grafts of adrenal medullary tissue has the advantage of using a readily available source of tissue without the problems of immunosuppression. However, these cells have not proven to be as effective as fetal neurons, probably because they do not fully differentiate into neurons. In animal models, brief treatment with nerve growth factor can facilitate such differentiation. This study is a clinical evaluation of the efficacy of adrenal medullary cell transplantation, combined with nerve growth factor infusion. Two patients were selected who were moderately to severely affected (Hoehn-Yahr stage 2 in on-phase and stage 4 in off-phase). After adrenalectomy, small pieces of medulla were prepared and implanted stereotactically into the dorsal putamen on one side of the brain. A catheter filled with mouse beta-nerve growth factor (NGF) was placed close to the grafts. Infusion of NGF was continued for one month. Despite a progressively deteriorating course prior to surgery, both patients showed improvement on the rating scales postoperatively. There was also significant improvement in timed motor tests. Motor readiness evoked potentials showed increased voltage over the operated hemisphere. The study points to methods and feasibility of supplying nerve growth factor intraparenchymally to the human brain. Possible implications with respect to other growth factors, particularly Glial cell-line Derived Neurotrophic factor (GDNF) are discussed.

Encapsulated cell biodelivery of nerve growth factor to the Basal forebrain in patients with Alzheimer's disease

BACKGROUND/AIMS

Degeneration of cholinergic neurons in the basal forebrain correlates with cognitive decline in patients with Alzheimer's disease (AD). Targeted delivery of exogenous nerve growth factor (NGF) has emerged as a potential AD therapy due to its regenerative effects on the basal forebrain cholinergic neurons in AD animal models. Here we report the results of a first-in-man study of encapsulated cell (EC) biodelivery of NGF to the basal forebrain of AD patients with the primary objective to explore safety and tolerability.

METHODS

This was an open-label, 12-month study in 6 AD patients. Patients were implanted stereotactically with EC-NGF biodelivery devices targeting the basal forebrain. Patients were monitored with respect to safety, tolerability, disease progression and implant functionality.

RESULTS

All patients were implanted successfully with bilateral single or double implants without complications or signs of toxicity. No adverse events were related to NGF or the device. All patients completed the study, including removal of implants at 12 months. Positive findings in cognition, EEG and nicotinic receptor binding in 2 of 6 patients were detected.

CONCLUSIONS

This study demonstrates that surgical implantation and removal of EC-NGF biodelivery to the basal forebrain in AD patients is safe, well tolerated and feasible.

Cardiovascular disease risk and the need for prevention after paraplegia determined by conventional multifactorial risk models: the Stockholm spinal cord injury study

OBJECTIVE

To assess the need for intervention on cardio-vascular disease risks in persons with paraplegia according to: (i) two multifactorial risk models; and (ii) these models in combination with the additional risk of overweight/obesity.

DESIGN

Cross-sectional.

SUBJECTS

A total of 134 out of 153 persons, comprising more than 80% of a regional prevalence population with traumatic paraplegia (American Spinal Injury Association Impairment Scale A-C) of minimum one year duration.

METHODS

Participants were screened for cardiovascular disease risk using two multifactorial risk models: the Systematic Coronary Risk Evaluation and the Framingham Risk Equation. Risk factors included were: age, gender, systolic blood pressure, antihypertensive medication, smoking, total cholesterol, high-density lipoprotein cholesterol, and total cholesterol/total cholesterol ratio. In addition, overweight/obesity was assessed by body mass index.

RESULTS

Twenty-seven percent to 36% of the cohort was eligible for cardiovascular disease risk intervention, depending on the risk model used. When overweight/obesity (spinal cord injury adjusted cut-score body mass index ≥ 22) was also considered, over 80% of the participants qualified for intervention.

CONCLUSION

Almost one-third of persons with paraplegia were eligible for cardiovascular disease risk intervention according to authoritative assessment tools. The number in need of intervention was dramatically increased when overweight/obesity as a cardiovascular disease risk was considered.

Increased cardiovascular disease risk in Swedish persons with paraplegia: The Stockholm spinal cord injury study

OBJECTIVE

Comparison of prevalence of cardiovascular disease risks in persons with chronic traumatic paraplegia with those in the general population.

DESIGN

Cross-sectional comparative study.

SUBJECTS

A total of 135 individuals, age range 18-79 years, with chronic (> or = 1 year) traumatic paraplegia.

METHODS

The prevalences of diabetes mellitus, dyslipidaemia, hypertension, overweight, and smoking, were assessed in the study population and were compared with an age- and gender-matched sample of the general population in the region under study. History of myocardial infarction and medication for dyslipidaemia, hypertension, and diabetes mellitus were also recorded. chi2 tests were used to compare the paraplegic cohort with the general population sample.

RESULTS

Significantly more persons with paraplegia reported a history of myocardial infarction (5.9%) than those in the comparison group (0.7%). The prevalences of diabetes mellitus (5.9%), dyslipidaemia (11.1%), and hypertension (14.1%) were also significantly higher in the paraplegic group, as were drug treatment for these disorders.

CONCLUSION

Persons with paraplegia report increased prevalences of diabetes mellitus, hypertension, and dyslipidaemia, in particular, compared with the general population. Population-based screening and therapeutic counter-measures for these conditions may therefore be particularly indicated for this patient group.

Cardiovascular disease risk factors in persons with paraplegia: the Stockholm spinal cord injury study

OBJECTIVE

To examine cardiovascular disease risk factors and risk clusters in Swedish persons with traumatic wheelchair-dependent paraplegia.

DESIGN

Prospective examination.

SUBJECTS

A total of 135 individuals aged 18-79 years with chronic (>or= 1 year) post-traumatic paraplegia.

METHODS

Cardiovascular disease risk factors; dyslipidemia, impaired fasting glucose, hypertension, overweight, smoking, and medication usage for dyslipidemia, hypertension, and diabetes mellitus, were analyzed according to authoritative guidelines. Stepwise regression tested the effects of age, gender, and injury characteristics on cardiovascular disease risks.

RESULTS

High-prevalence risk factors were dyslipidemia (83.1%), hypertension (39.3%), and overweight (42.2%) with pervasive clustering of these risks. Being older was related to increased cardiovascular disease risk, except for dyslipidemia. Hypertension was more common in low-level paraplegia. Prevalence of impaired fasting glucose was lower than previously reported after paraplegia. A high percentage of persons being prescribed drug treatment for dyslipidemia and hypertension failed to reach authoritative targets for cardiovascular disease risk reduction.

CONCLUSION

Swedish persons with paraplegia are at high risk for dyslipidemia, hypertension, and overweight. Impaired fasting glucose was not as common as reported in some previous studies. Pharmacotherapy for dyslipidemia and hypertension often failed to achieve recommended targets. Population-based screening and therapeutic countermeasures to these cardiovascular disease risks are indicated.

Recovery from unilateral neglect after right-hemisphere stroke

PURPOSE

To show the recovery process for different forms of unilateral neglect (UN)--including personal neglect and neglect of far space--in relationship to impairment, disability, cognition and mood.

METHOD

Patients were tested at 2-4 weeks, at 6 months and at 1 year. We used the Behaviour Inattention Test and a test for personal neglect. We also used the NIH Stroke Scale, the Functional Independence Measure (FIM), the Mini-Mental State Evaluation and the Geriatric Depression Scale.

RESULTS

Peripersonal neglect diminishes within 6 months, but complete recovery occurred in only 13%. The prognosis for personal neglect and neglect of far space is better, with a recovery ratio at 6 months of 52% and 46%, respective. The correlations between UN and FIM are high. A few patients deteriorate in the absence of recurrent stroke.

CONCLUSIONS

For clinical purposes, it is practical to postpone UN evaluation until a couple of weeks after a stroke. Many of the patients who then have UN are likely to retain their UN, although many will improve. Patients with UN should receive special attention in the rehabilitation phase, as well as at discharge. One explanation of the worsening of UN seen in some patients, may be continuing cerebral atherosclerosis.

Clinician perceived good practice in end-of-life care for patients with COPD

Patients with chronic obstructive pulmonary disease (COPD) have significant end-of-life needs, but are much less likely than patients with cancer to access or receive appropriate palliative care. Little is known about the existing availability or quality of available services within the United Kingdom. We surveyed 100 NHS acute hospitals enquiring into the provision of care for patients with COPD and requesting examples of current good practice that might be used to set standards. Forty-two percent of hospitals had formal palliative care arrangements for patients with COPD, whereas 59% had plans to develop or further develop services. Analysis of qualitative data suggested four strands that highlighted good practice; teams, care pathways, service components and linkages. These data may help to inform the debate leading to the development of standards in end-of-life care for patients with COPD.

Long-term culture and neuronal survival after intraspinal transplantation of human spinal cord-derived neurospheres

There is heterogeneity in neural stem and progenitor cell characteristics depending on their species and regional origin. In search for potent in vitro-expanded human neural precursor cells and cell therapy methods to repair the injured human spinal cord, the possible influence exerted by intrinsic cellular heterogeneity has to be considered. Data available on in vitro-expanded human spinal cord-derived cells are sparse and it has previously been difficult to establish long-term neurosphere cultures showing multipotentiality. In the present paper, human spinal cord-derived neurospheres were cultured in the presence of EGF, bFGF and CNTF for up to 25 passages (>350 days) in vitro. In contrast to the human first trimester subcortical forebrain, spinal cord tissue>9.5 weeks of gestation could not serve as a source for long-term neurosphere cultures under the present conditions. After withdrawal of mitogens, cultured neurospheres (at 18 passages) gave rise to cells with neuronal, astrocytic and oligodendrocytic phenotypes in vitro. After transplantation of human spinal cord-derived neurospheres to the lesioned spinal cord of immuno-deficient adult rats, large numbers of cells survived at least up to 6 weeks, expressing neuronal and astrocytic phenotypes. These results demonstrate that it is possible to expand and maintain multipotent human spinal cord-derived neurospheres in vitro for extended time-periods and that they have promising in vivo potential after engraftment to the injured spinal cord.

Late human cytomegalovirus (HCMV) proteins inhibit differentiation of human neural precursor cells into astrocytes

Human cytomegalovirus (HCMV) is the most common cause of congenital infections in developed countries, with an incidence varying between 0.5-2.2%. Such infection may be the consequence of either a primary infection or reactivation of a latent infection in the mother and the outcome may vary from asymptomatic to severe brain disorders. Moreover, infants that are asymptomatic at the time of birth may still develop neurologic sequelae at a later age. Our hypothesis is that infection of stem cells of the central nervous system by HCMV alters the proliferation, differentiation or migration of these cells, and thereby gives rise to the brain abnormalities observed. We show that infection of human neural precursor cells (NPCs) with the laboratory strain Towne or the clinical isolate TB40 of HCMV suppresses the differentiation of these cells into astrocytes even at an multiplicity of infection (MOI) as low as 0.1 (by 33% and 67%, respectively). This inhibition required active viral replication and the expression of late HCMV proteins. Infection as late as 24 hr after the onset of differentiation, but not after 72 hr, also prevented the maturation of infected cultures. Furthermore, in cultures infected with TB40 (at an MOI of 1), approximately 54% of the cells were apoptotic and cell proliferation was significantly attenuated. Clearly, HCMV can reduce the capacity of NPCs to differentiate into astrocytes and this effect may provide part of the explanation for the abnormalities in brain development associated with congenital HCMV infection.

Cellular composition of long-term human spinal cord- and forebrain-derived neurosphere cultures

In vitro expanded neural precursor cells (NPCs) may provide a stable source for cell therapy. In search of the optimal cell source for spinal cord repair, we investigated influences of gestational age, regional heterogeneity, and long-term in vitro propagation. The cellular content of neurosphere cultures prior to and after in vitro differentiation was studied by immunocytochemistry and flow cytometry. Human forebrain and spinal cord NPCs deriving from first-trimester tissue were cultured as neurospheres in the presence of epidermal growth factor, basic fibroblast growth factor, and ciliary neurotrophic factor. Proteins characteristic for embryonic stem cells, i.e., Tra-1-60, Tra-1-81, and SSEA-4, were present in approximately 0.5% of the cells in donor tissues and neurospheres. The proportions of nestin- and proliferating cell nuclear antigen-immunoreactive (IR) cells were also maintained, whereas the CD133-IR population increased in vitro. Glial fibrillary acidic protein-IR cells increased in number, and in contrast the fraction of beta-tubulin III-IR cells decreased, at and beyond passage 5 in spinal cord but not forebrain cultures. However, dissociated and in vitro-differentiated forebrain- and spinal cord-derived neurospheres generated similar proportions of neurons, astrocytes, and oligodendrocytes. Gestational age of the donor tissue, which ranged from 4.5 to 12 weeks for forebrain and from 4.5 to 9.5 weeks for spinal cord, did not affect the proportion of cells with different phenotypes in culture. Thus, cellular composition of human neurosphere cultures differs as a result of long-term in vitro propagation and regional heterogeneity of source tissue, despite expansion under equal culture conditions. This could in turn imply that human spinal cord and forebrain NPCs present different repair potentials in in vivo settings.

Human cytomegalovirus inhibits neuronal differentiation and induces apoptosis in human neural precursor cells

Human cytomegalovirus (HCMV) is the most common cause of congenital infections in developed countries, with an incidence varying between 0.5 and 2.2% and consequences varying from asymptomatic infection to lethal conditions for the fetus. Infants that are asymptomatic at birth may still develop neurological sequelae, such as hearing loss and mental retardation, at a later age. Infection of neural stem and precursor cells by HCMV and consequent disruption of the proliferation, differentiation, and/or migration of these cells may be the primary mechanism underlying the development of brain abnormalities. In the present investigation, we demonstrate that human neural precursor cells (NPCs) are permissive for HCMV infection, by both the laboratory strain Towne and the clinical isolate TB40, resulting in 55% and 72% inhibition of induced differentiation of human NPCs into neurons, respectively, when infection occurred at the onset of differentiation. This repression of neuronal differentiation required active viral replication and involved the expression of late HCMV gene products. This capacity of HCMV to prevent neuronal differentiation declined within 24 h after initiation of differentiation. Furthermore, the rate of cell proliferation in infected cultures was attenuated. Surprisingly, HCMV-infected cells exhibited an elevated frequency of apoptosis at 7 days following the onset of differentiation, at which time approximately 50% of the cells were apoptotic at a multiplicity of infection of 10. These findings indicate that HCMV has the capacity to reduce the ability of human NPCs to differentiate into neurons, which may offer one explanation for the abnormalities in brain development associated with congenital HCMV infection.

Induction of dopaminergic neurons from growth factor expanded neural stem/progenitor cell cultures derived from human first trimester forebrain

Multipotent stem/progenitor cells derived from human first trimester forebrain can be expanded as free-floating aggregates, so called neurospheres. These cells can differentiate into neurons, astrocytes and oligodendrocytes. In vitro differentiation protocols normally yield gamma-aminobutyric acid-immunoreactive neurons, whereas only few tyrosine hydroxylase (TH) expressing neurons are found. The present report describes conditions under which 4-10% of the cells in the culture become TH immunoreactive (ir) neurons within 24h. Factors including acidic fibroblast growth factor (aFGF) in combination with agents that increase intracellular cyclic AMP and activate protein kinase C, in addition to a substrate that promotes neuronal differentiation appear critical for efficient TH induction. The cells remain THir after trypsinization and replating, even when their subsequent culturing takes place in the absence of inducing factors. Consistent with a dopaminergic phenotype, mRNAs encoding aromatic acid decarboxylase, but not dopamine-beta-hydroxylase were detected by quantitative real time RT-PCR. Ten weeks after the cells had been grafted into the striatum of adult rats with unilateral nigrostriatal lesions, only very few of the surviving human neurons expressed TH. Our data suggest that a significant proportion of expandable human neural progenitors can differentiate into TH-expressing cells in vitro and that they could be useful for drug and gene discovery. Additional experiments, however, are required to improve the survival and phenotypic stability of these cells before they can be considered useful for cell replacement therapy in Parkinson's disease.

HOW TO IDENTIFY POTENTIAL FALLERS IN A STROKE UNIT: VALIDITY INDEXES OF 4 TEST METHODS

OBJECTIVE

The aim of this study was to describe general characteristics of patients with stroke who have a tendency to fall and to determine whether certain test instruments can identify fallers.

METHODS

Patients treated in a stroke unit during a 12-month period were included. At inclusion assessments were made with Berg Balance Scale Berg Balance Scale, Stops Walking When Talking, Timed Up & Go (TUG) and diffTUG. At follow-up 6 or 12 months later, patients who had fallen were identified.

RESULTS

During the time from discharge to follow-up on 159 patients, 68 patients fell and 91 did not. Fallers fell more often during their initial hospital stay, used sedatives more often and were more visually impaired, compared with non-fallers. The Berg Balance Scale, Stops Walking When Talking and TUG results differed between fallers and non-fallers. The combined results of Berg Balance Scale and Stops Walking When Talking increased the possibility of identifying fallers.

CONCLUSION

Berg Balance Scale, Stops Walking When Talking and TUG can be used to evaluate which patients have a tendency to fall in order to carry out preventive measures. Berg Balance Scale can be used in all patients. Stops Walking When Talking can give additional information if the patient is able to walk. TUG is a possible choice, but fewer patients can perform it.

Identification of novel genes regulated in the developing human ventral mesencephalon

In the human embryo, from approximately 6 weeks gestational age (GA), dopaminergic (DA) neurons can be found in the ventral mesencephalon (VM). More specifically, the post-mitotic neurons are located in the ventral part of the tegmentum (VT), whereas no mature DA neurons are found in the neighboring dorsal part. We used Affymetrix HG-U133 GeneChip technology to compare genome-wide expression profiles of ventral and dorsal tegmentum from 8 weeks GA human embryos, in order to identify genes involved in specification, differentiation, and survival of mesencephalic DA (mDA) neurons. Known mDA marker genes including ALDH1A1, DAT1, VMAT2, TH, CALB1, NURR1, FOXA1, GIRK2, PITX3, RET, and DRD2 topped the list of 96 genes from HG-U133A with higher expression in VT, validating the experimental set-up. In addition, 28 probes from HG-U133B were identified whereof most are annotated to UniGene clusters with no gene associated or to genes of unknown function. Of these, the fifteen most regulated transcripts, representing changes down to 56% could be verified by quantitative real-time PCR (Q-PCR) on a developmental series of subdissected human embryonic and fetal brain material, resulting in not only a regional but also a temporal expression profile. This revealed a distinct DA-associated profile for in particular a putative transcription factor (FLJ45455) and the uncharacterized transmembrane proteins KIAA1145 and SLC10A4. The data presented here may help to device cell replacement and regenerative therapies for Parkinson's disease (PD).

Quality of life in terminal care—with special reference to age, gender and marital status

OBJECTIVES

This study was conducted to explore symptoms, other quality of life (QoL) aspects and impact of age, gender, marital status, cancer diagnosis and time of survival in patients with advanced cancer admitted to palliative care.

PATIENTS AND METHODS

A cross-sectional study of 278 cancer patients completing the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 at referral to palliative care.

MAIN RESULTS

Gynaecological and gastro-intestinal tract cancers were the most common. Mean age was 67 years; 62% were female. Median survival was 43 days and 39% lived less than 30 days. Patients reported impaired general QoL and high occurrence of symptoms (44 and 100% for diarrhoea and fatigue, respectively). Fatigue, appetite loss and dyspnoea were reported as most severe (mean values of 80, 59 and 51, respectively, 0-100 scales). Married/cohabiting patients and younger patients reported lower functional abilities and more symptoms. No impact of diagnoses on QoL parameters was found. Patients closest to death did not differ significantly from those with longer time to live in social functioning.

CONCLUSION

Young and married patients may be at higher risk for perceived low quality of life at the end of life. EORTC QLQ-C30 could be used as a clinical tool for screening of symptoms and reduced functioning in palliative care, but may not be appropriate for use in the most severely ill patients. Limitations of the instrument and the need for robust measurements of patient mix are discussed. Proxy ratings of physical symptoms and nurse responsibility to include QoL assessment in daily practice would increase attrition and decrease selection bias.

Increased fiber outgrowth from xeno-transplanted human embryonic dopaminergic neurons with co-implants of polymer-encapsulated genetically modified cells releasing glial cell line-derived neurotrophic factor

We investigated whether a continuous supply of glial cell line-derived neurotrophic factor (GDNF) via encapsulated genetically modified cells can promote survival and fiber outgrowth from xenotransplanted human dopaminergic neurons. Cells genetically engineered to continuously secrete GDNF were confined in hollow fiber-based macrocapsules. Each hemiparkinsonian rat received either a single C2C12-hGDNF capsule (n=8) or a C2C12-control capsule (n=8) concomitantly with human embryonic ventral mesencephalic cell suspension transplants. Our results show that fiber outgrowth in the area between the capsule and the graft is more extensive in rats with GDNF-releasing capsules than in rats with control capsules. We suggest that continuous and safe delivery of GDNF to the brain could be a potential way to optimize neural transplantation as a therapy for Parkinson's disease.

Postural steadiness and weight distribution during tandem stance in healthy young and elderly adults

BACKGROUND

Tandem stance is a clinical measure of standing balance considered to assess postural steadiness in a heel-to-toe position by a temporal measurement. To our knowledge, no studies have evaluated the change of postural steadiness, expressed as force variability, over time. The objective of this paper is to investigate postural steadiness during 30 s of tandem stance in healthy elderly and young adults, and to explore the weight distribution between legs during tandem stance.

METHODS

A cross-sectional analysis comparing ground reaction forces and muscle activity in 26 healthy elderly adults (mean age 70.6 years) and 27 healthy young adults (mean age 30.0 years). Ground reaction forces beneath both feet and muscle activity of ankle muscles were recorded while the subjects performed 30 s of tandem stance during two conditions.

FINDINGS

Two phases were identified in both groups: First a dynamic phase, a decrease in force variability during the first 3-4 s after foot placement, and thereafter a static phase, maintaining a certain level of force variability. Age-related changes were seen in the decrease in force variability (P<0.001) and ankle muscle activity (P<0.001). However, both groups placed more weight on the rear leg (P<0.001).

INTERPRETATION

The first few seconds of tandem stance pose the greatest challenge to postural steadiness and influence the static phase. We suggest that the dynamic phase is the most crucial period of time for assessing balance requirements. Independent of age, tandem stance is not a task for equal weight bearing.

Smoking during early pregnancy affects the expression pattern of both nicotinic and muscarinic acetylcholine receptors in human first trimester brainstem and cerebellum

Prenatal nicotine exposure is associated with an increased risk of complications during pregnancy and childhood. In this study the expression of nicotinic and muscarinic acetylcholine receptors in first trimester pons, medulla oblongata and cerebellum from abortus (5-12 weeks of gestation) of smoking and nonsmoking women was compared. A significant age-related increase in binding of nicotinic receptor subtype alpha4 was found in both pons and cerebellum only in fetal tissue from non-smoking women, while a similar increase was observed in medulla oblongata from fetuses exposed to smoking. A significant age-related increase in binding of muscarinic receptor subtype m2 was observed in pons from abortus of smoking compared with non-smoking women. The gene expression pattern of both alpha4 and alpha7 nicotinic receptor subunits was changed after smoking in all three regions investigated. Smoking also changed the expression of m1 and 2 muscarinic receptor mRNA in pons, m1 mRNA in cerebellum and the m3 mRNA in medulla oblongata. The findings indicate that early prenatal nicotine exposure affects the normal developmental pattern of the cholinergic system in human fetal brain.

One-leg stance in healthy young and elderly adults: a measure of postural steadiness?

OBJECTIVE

To investigate postural steadiness during 30 s of one-leg stance in healthy young and elderly adults, by analysing the pattern of the ground reaction force variability.

DESIGN

A laboratory set-up was used to analyse the variability of the ground reaction forces in relation to time as a measure of postural steadiness.

BACKGROUND

The one-leg stance test is a measure considered to assess postural steadiness in a static position by a temporal measurement. The common notion is that a better postural steadiness, i.e. less force variability, allows for longer time standing on one leg. However, there is lack of evidence how postural steadiness during one-leg stance changes over time.

METHODS

Twenty-eight healthy elderly and 28 healthy young adults were tested by means of force plates assessing ground reaction forces while performing one-leg stance.

RESULTS

During one-leg stance, two phases could be identified in both groups: First a dynamic phase, a rapid decrease of force variability, and thereafter a static phase, maintaining a certain level of force variability. During the first 5 s of one-leg stance the force variability decreased significantly more in the young group resulting in a lower force variability level during the static phase than in the elderly.

CONCLUSIONS

The difficulties in maintaining the static position in elderly seems dependent on the reduced initial decrease in force variability and/or musculoskeletal components. We suggest that the first 5 s are crucial when assessing balance during one-leg stance.

Distribution of presenilin 1 and 2 and their relation to Notch receptors and ligands in human embryonic/foetal central nervous system

Notch signaling in vertebrates is mediated by four Notch receptors (Notch-1, -2, -3, and -4) that are activated by interacting with at least five different Notch ligands, Jagged-1, Jagged-2, Delta-1, -2, and -3. Recent studies have shown that the gamma-secretase-like intramembranous cleavage of Notch receptors to release their cytoplasmic signaling domains requires the presenilin (PS) proteins 1 and 2 (PS1 and PS2). Here, we used immunohistochemistry to compare the distribution of all four Notch receptor proteins and three ligands in the context of co-localization with PS1 and PS2 in first trimester human central nervous system (CNS). In addition, we investigated Notch receptors and ligands expression by Western blotting. The study was performed on the forebrain and spinal cord of human embryonic/foetal CNS (5-11 gestational weeks). Results showed a divergent distribution of the different Notch receptor proteins with only Notch-1 being co-localized with PS1 and PS2. Notch-2 was only seen occasionally within the developing cortex and spinal cord. Notch-3 expression was restricted to neuroepithelial cells of the spinal cord and endothelial cells in blood vessels of both developing cerebral cortex and spinal cord. The weak, punctate staining of Notch-4 in the neuroepithelium of the spinal cord could not be confirmed with Western blotting. Neither Notch-2, nor -3 showed overlap with either PS1 or PS2 immunoreactivity. The ligand Jagged-1 was found sporadically in the neuroepithelial cell layer in cerebral cortex of the earlier stages of development and of the spinal cord during the first trimester while Jagged-2 was not detected. Jagged-1 and Jagged-2 immunoreactivities were not found in the 9-11-week cortex. No co-distribution of Jagged-1 and PS1 or PS2 was found. Delta-1 ligand expression was detected in neuroepithelial cells of the ventricular zone of the cerebral cortex, and also in maturating neurons in the cortical plate and ventral horns of the developing spinal cord. The presence of Notch-1, Delta-1 and Jagged-1 in the neuroepithelium of developing CNS indicates that Notch signaling in proliferating human progenitor cells only involves these two receptor ligands and that cleavage of Notch-1 is mediated both by PS1 and PS2. The strong immunoreactivity of Notch-1, Delta-1 and PS1 in the cortical plate and in maturating neurons of the spinal cord also suggests that these proteins may regulate the maturation processes of post-mitotic neurons. The pronounced PS1 immunoreactivity in neurites in the hindbrain and spinal cord without detectable expression of any Notch receptor or ligand suggests that a possible role for PS1 in neurite growth involves either gamma-secretase-mediated cleavage of other substrates or gamma-secretase-independent mechanisms.

Presenilin expression during induced differentiation of the human neuroblastoma SH-SY5Y cell line

Human neuroblastoma SH-SY5Y cells stably transfected with both wild-type and exon-9 deleted (deltaE9) presenilin constructs were used to study the role of the presenilin proteins during differentiation. Cells transfected with either wild-type or deltaE9 PS1, of which the latter abolishes normal endoproteolytic cleavage of the protein, showed no obvious differences in their ability to differentiate to a neuronal-like phenotype upon treatment with retinoic acid (RA). A defined pattern of PS1 expression was observed during differentiation with both RA and the phorbol ester TPA. Full-length PS1 was shown to increase dramatically within 5-24 h of RA treatment. TPA gave an earlier and longer lasting increase in full-length PS1 levels. The intracellular distribution pattern of PS1 was markedly altered following RA treatment. Within 24h PS1 was highly up-regulated throughout the cell body around the nucleus. Between 2 and 4 weeks PS1 staining appeared punctate and also localised to the nucleus. Increases in PS1 expression upon treatment with RA and TPA were blocked by treatment with cycloheximide, indicating a role of de-novo protein synthesis in this effect. PS2 expression remained unchanged during differentiation. Levels of full-length PS1 were also seen to increase during neurogenesis and neuronal differentiation in the forebrain of first trimester human foetuses between 6.5 and 11 weeks. These combined observations support the idea that PS1 is involved in neuronal differentiation by a mechanism likely independent of endoproteolysis of the protein.

Prognosis for patients with neglect and anosognosia with special reference to cognitive impairment

OBJECTIVE

To describe prognosis in patients with unilateral neglect, anosognosia, or both, within a community based stroke cohort.

METHODS

Patients (n = 377) were evaluated at baseline for the presence of neglect and anosognosia. After 1 year, the level of disability was established in survivors. Predictors for death and dependency were examined in multivariate analysis. The following independent variables were used: age, consciousness, hemianopia, arm paresis, leg paresis, sensory disturbance, aphasia, neglect, anosognosia, diabetes mellitus, cardiovascular disease, pre- and post-stroke cognitive impairment.

RESULTS

Age, consciousness and sensory disturbance predicted death. Post-stroke cognitive impairment, neglect, hemianopia, arm paresis and age predicted dependency.

CONCLUSION

Neglect in the acute phase, which occurs in patients irrespective of pre-stroke cognitive level, negatively affects disability after 1 year. Anosognosia more often occurs in patients who are cognitively impaired before the stroke. These patients often are ADL-dependent already, or become dependent because of cognitive impairment, not because of anosognosia.

Higher expression of alpha7 nicotinic acetylcholine receptors in human fetal compared to adult brain

Neuronal nicotinic acetylcholine receptors are thought to be involved in regulation of several processes during neurogenesis of the brain. In this study the expression of the alpha7 nicotinic acetylcholine receptor subtype was investigated in human fetal (9-11 weeks of gestation), middle-aged (28-51 years) and aged (68-94 years) medulla oblongata, pons, frontal cortex, and cerebellum. The specific binding of the alpha7 receptor antagonist [(125)I]alpha-bungarotoxin was significantly higher in fetal than in both middle-aged and aged medulla oblongata and aged pons. No significant decrease in [(125)I]alpha-bungarotoxin binding sites was observed from fetal to adult cortex and cerebellum. The alpha7 mRNA expression was significantly higher in all fetal brain regions investigated, except for aged cortex, than in corresponding middle-aged and aged tissue. The high expression of alpha7 nicotinic acetylcholine receptors in fetal compared to adult brain supports the view that these receptors play an important role during brain development.

Assessing unilateral neglect: shortcomings of standard test methods

INTRODUCTION

When investigating the incidence of unilateral neglect in a first-ever stroke population, we found that some patients showed clinical signs of neglect, but managed to pass our tests. The purpose of this paper is to describe the nature of such signs, and analyse why test instruments were insufficiently corresponding to those signs.

METHOD

One hundred and thirty-one consecutive patients with first-ever stroke in a community-based sample were evaluated for the presence of unilateral neglect. We used a test battery consisting of tests for visuo-spatial neglect, personal neglect, and anosognosia. Twenty cases of neglect were discovered by standard methods. We asked our collaborators at the wards to report any behavioural abnormality reminiscent of neglect present in patients who had normal test results. Such patients were evaluated clinically.

RESULTS

Nine cases with neglect-like symptoms were discovered. Our clinical evaluation of the nine patients indicated several possible explanations for their behavioural abnormalities, including motor neglect, neglect for far extrapersonal space, disturbances of proprioception, and spatial disturbances other than neglect.

CONCLUSION

Standard neglect tests do not cover all clinical forms of neglect. It is therefore important not to rely completely on test instruments when diagnosing neglect. More versatile test instruments are desired.

Societal services after traumatic spinal cord injury in Sweden

OBJECTIVE

Societal services after traumatic spinal cord injury in Sweden were investigated, including self-rated levels of satisfaction with the application process and resource allocation.

DESIGN

Survey of an incidence population.

SUBJECTS

Thirty-four persons of a total regional incidence population (n = 48) with traumatic spinal cord injury.

METHODS

Structured interviews using a standardized questionnaire.

RESULTS

About 25 separate services were identified being available for persons with traumatic spinal cord injury. The average number of applications per person was 5 (range 0-11). The most common service was "transportation service". Of the applications, 17% were partially or totally rejected. Most subjects received information about available services from a social worker. For 13 available services at least 1 subject claimed ignorance about its existence.

CONCLUSIONS

In Sweden, significant resources are allocated for allowing independence and financial compensation for individuals with traumatic spinal cord injury. However, this support system sometimes also results in frustration and disappointment. Insufficient information and co-ordination are reported as weaknesses. The persons' efforts to acquire knowledge of how the system works take time which could be better used for rehabilitation and full integration into the community.

High incidence rates of stroke in Orebro, Sweden: Further support for regional incidence differences within Scandinavia

BACKGROUND AND PURPOSE

As a basis for comparison of differences in stroke incidence in Scandinavian countries, a community-based stroke register was established in Orebro in the centre of Sweden.

METHODS

All first-ever cases of stroke were registered during a 12-month period 1999-2000. The study population was 123,503. The WHO definition of stroke was used. Cases were searched inside as well as outside hospital. Multiple overlapping sources and 'hot pursuit' technique were used in the process of case ascertainment.

RESULTS

388 cases of first-ever stroke were found, corresponding to a crude incidence rate of 314 (95% CI, 283-348) per 100,000 per year, 337 (95% CI, 294-386) for females, and 289 (95% CI, 248-336) for males. Adjusted to the European population, the corresponding rates were 254 (95% CI, 227-284) per 100,000 per year, 273 (95% CI, 238-311) for females and 232 (95% CI, 206-261) for males. The overall 28-day case-fatality rate was 19% (95% CI, 15-23). The case-fatality rates for the different subtypes of stroke were as follows: brain infarction, 10%; intracerebral haemorrhage, 20%; subarachnoidal haemorrhage 45%, and undetermined pathological type 56%.

CONCLUSIONS

The present study as well as other studies in northern and middle Scandinavia show significantly higher incidence rates than studies from other regions. The crude incidence rate, reflecting the age distribution of the population, is even higher, indicating a burden to the community that is rather increasing than decreasing.

Expression patterns of neurotrophic factor mRNAs in developing human teeth

Neurotrophic factors regulate survival, differentiation, growth and plasticity in the nervous system. In addition, based on their specific and shifting temporospatial expression patterns, neurotrophic factors have been implicated in morphogenetic events during tooth development in rodents. To determine whether these findings in rodents could be related to humans, we have now studied nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), neurotrophin-4 (NT-4), glial cell-line derived neurotrophic factor (GDNF), and neurturin (NTN) mRNA expression patterns in developing human teeth during gestational weeks 6.5-11. Using in situ hybridization histochemistry, we found distinct and specific patterns of neurotrophin and GDNF mRNA expression in the developing human teeth. NGF mRNA labeling was weak and confined predominantly to the dental papilla. BDNF mRNA labeling was stronger than NGF mRNA and was seen in the mesenchyme located lateral to the dental organ, as well as in epithelial structures (inner dental epithelium and enamel knot). NT-3 mRNA was observed in the dental papilla and in the area of the cervical loop. NT-4 mRNA was expressed in both oral and dental epithelia in all stages studied. GDNF mRNA was found in the dental follicle and at different sites in the inner dental epithelium. Weak NTN mRNA labeling was also found in the developing teeth. Based on these findings, we suggest that neurotrophins, GDNF and NTN might be involved in morphogenetic events during early stages of tooth development in humans. Protein gene product (PGP) 9.5-immunoreactive nerve fibers were observed in the dental follicle by 11 weeks coinciding with the labeling for neurotrophic factor mRNAs in this structure. This suggests that these neurotrophic factors might be involved in the innervation of dental structures. The rich expression of neurotrophic factors in developing dental tissues suggests that developing, or possibly adult, dental tissue might be used as an allograft source of trophic support for diseases of the nervous system.

Predictors of severe stroke: influence of preexisting dementia and cardiac disorders

BACKGROUND AND PURPOSE

There is little research into the impact of prestroke dementia on stroke severity and short-term mortality. We included prestroke dementia, along with other risk factors, to determine independent predictors of stroke severity and early death in a community-based stroke study.

METHODS

All patients (n=377) with a first-ever stroke were evaluated in terms of risk factors. Registration took place over a 12-month period. Stroke severity was evaluated with the National Institutes of Health Stroke Scale. Predictors of severe stroke and early death were analyzed in logistic regression models. The following independent variables were used: age, sex, living alone, arterial hypertension, ischemic heart disease, heart failure, atrial fibrillation, diabetes mellitus, transient ischemic attack, cigarette smoking, peripheral atherosclerosis, and dementia.

RESULTS

Risk factors for stroke were found in 82% of the patients. Heart failure, atrial fibrillation, and dementia were associated with more severe strokes. Dementia, atrial fibrillation, heart failure, and living alone were associated with death within 28 days of the event.

CONCLUSIONS

These results raise the question of whether certain high-risk patients, ie, patients with atrial fibrillation, heart failure, and dementia, can benefit from more aggressive primary and secondary stroke prevention measures.

Neglect and anosognosia after first-ever stroke: incidence and relationship to disability

Neglect and anosognosia are serious consequences of stroke. Authors have found great variations in their incidence and their relationship to disability has been unclear. We studied the incidence of neglect and anosognosia within the scope of a population-based stroke-incidence study, and also evaluated their impact on disability. Four tests of visuo-spatial neglect, four tests of personal neglect, and an anosognosia questionnaire were used. Sixty-two patients (23%) of the study group had visuo-spatial neglect according to our definition, 21 patients (8%) had personal neglect, and 48 (17%) showed signs of anosognosia. Using a multiple logistic regression model, we found that both neglect and anosognosia influenced disability. To ascertain the true incidence of neglect and anosognosia after stroke, it is necessary to use a community-based study design, where cases treated outside the hospital are included. Some of the variability found in previous incidence studies is likely to be explained by not using such a design.

Constitutive and inflammatory induction of alpha and beta chemokines in human first trimester forebrain astrocytes and neurons

Chemokine effects on leukocyte infiltration into the central nervous system (CNS) are key events in the inflammatory processes of neuroimmunologic and neuroinfectious diseases. Because, chemokines may play important roles in proliferation and differentiation of brain cells and in the initiation and progression of CNS inflammatory disorders, we analyzed constitutive and inflammatory-induced expression of alpha and beta chemokines in human first trimester forebrain cells. Constitutive induction of IL-8, MIP-1alpha, MIP-1beta, MCP-1 and regulated on activation, normal T-cell expressed, and secreted (Rantes) was detected in cryostat sections of embryonic forebrains in an age-dependent manner. Dissociated cell cultures were studied for spontaneous chemokine induction and after stimulation with the trypanosome lymphocyte triggering factor (TLTF), a novel trypanokine secreted by African trypanosomes that triggers a complex of immune responses. LPS and variant surface glycoprotein (VSG) were used as controls. In cultures, unstimulated cells expressed minimal chemokine levels except for Rantes. In response to TLTF and LPS, but not VSG, all chemokines were highly induced at the mRNA and protein levels in a dose- and age-dependent manner. Combined assays (in situ hybridization and immunohistochemistry) revealed that astrocytes and neurons are major sources for chemokines. These results illustrate the ability of resident brain cells to constitutively express chemokine genes, which may suggest an important role for chemokines during brain development. Furthermore, TLTF-induced chemokine expression in astrocytes and neurons indicate the capacity of TLTF to provoke neuroinflammation in the brain, which may have important therapeutic implications for the neurological manifestations of African trypanosomiasis.

Cloning and expression of the human N-methyl-D-aspartate receptor subunit NR3A

Native N-methyl-D-aspartate (NMDA) receptors are heteromeric assemblies of four or five subunits. The NMDA receptor subunits, NR1, NR2A, NR2B, NR2C, and NR2D have been cloned in several species, including man. The NR3A subunit, which in rodents is predominantly expressed during early development, seems to function by reducing the NMDA receptor response. The human homologue to the rat NR3A, however, had not been cloned. In order to study the functions of the human NR3A (hNR3A), we have cloned and sequenced the hNR3A. It was found to share 88% of the DNA sequence with the rat gene, corresponding to a 93% homology at the amino acid level. Based on available data from human genome databases, we localized the gene to chromosome 9. The transcript could be detected by in situ hybridization in human fetal spinal cord and forebrain. Two splice variants of NR3A have been reported in rat brain, the longer of the two containing a 60 bp insert in the intracellular domain. We were unable to detect this 60 bp insert in fetal or adult human brain, suggesting that only the short variant is expressed in humans.

Movement-provoked muscle torque and EMG activity in longstanding motor complete spinal cord injured individuals

Muscle resistance was evaluated by measurement of movement-provoked torque performed during simultaneous thigh muscle EMG recordings in individuals with a motor complete spinal cord injury (SCI). Fifteen men with a motor complete (ASIA grade A or B) cervical injury participated in the study. The activity started at an average of 0.11 seconds after the start of the provoking movement as evidenced by EMG recordings. However, no activity at all was found before the end of the movement provocation for 0.3 seconds in >60% of the test situations, whereas muscle torque was recorded in all cases. Significantly higher resistive muscle torque (p = 0.049) was provoked during extension movement compared with that of flexion. On the contrary, the maximum muscle activity was significantly higher (p = 0.009) during flexion movement compared with that during extension, with no differences between muscle groups. The resistive muscle torque seems to measure the passive viscoelastic component rather then the active spastic component of the movement-provoked muscle resistance in our group of motor complete SCI individuals.

The alpha7 nicotinic receptors in human fetal brain and spinal cord

The alpha7 nicotinic acetylcholine receptor subtype is believed to be involved in the regulation of neuronal growth, differentiation and synapse formation during the development of the human brain. In this study the expression of the alpha7 nicotinic acetylcholine receptor was investigated in human fetal brain and spinal cord of 5-11 weeks gestational age. Both the specific binding of [125I]alpha-bungarotoxin to prenatal brain membranes and the expression of alpha7 mRNA were significantly higher in the pons, medulla oblongata, mesencephalon and spinal cord of 9-11 weeks gestational age compared with cerebellum, cortex and subcortical forebrain. A significant positive correlation between gestational age and the expression of alpha7 mRNA was observed in all brain regions except cortex. A positive correlation was also observed between the gestational age and the [125I]alpha-bungarotoxin binding in the pons, medulla oblongata, mesencephalon, and cerebellum. Consequently, a significant relationship between the alpha7 mRNA levels and the binding sites for [125I]alpha-bungarotoxin was found in the fetal brain. The increasing levels of the alpha7 nicotinic acetylcholine receptor during the first trimester support the important role of nAChRs for the development of the central nervous system.

African trypanosomes activate human fetal brain cells to proliferation and IFN-gamma production

We addressed the host-parasite interplay and the immunopathogenetic events occurring in the central nervous system (CNS) during human African trypanosomiasis. Human first trimester forebrain cells were stimulated with a trypanosome lymphocyte-triggering factor (TLTF) and studied for their immune response as exemplified by cell proliferation and IFN-gamma production. TLTF induced proliferation of human first trimester forebrain cells and IFN-gamma production at the mRNA and protein levels. Astrocytes are the major producers of IFN-gamma in response toTLTE These data illustrated for the first time a direct effect of a parasite factor on human brain cells. TargetingTLTF during the course of the disease may be considered in preventing the deadly neurological complications of human African trypanosomiasis. NeuroReport

Spontaneous axonal regeneration in rodent spinal cord after ischemic injury

Here we present evidence for spontaneous and long-lasting regeneration of CNS axons after spinal cord lesions in adult rats. The length of 200 kD neurofilament (NF)-immunolabeled axons was estimated after photochemically induced ischemic spinal cord lesions using a stereological tool. The total length of all NF-immunolabeled axons within the lesion cavities was increased 6- to 10-fold at 5, 10, and 15 wk post-lesion compared with 1 wk post-surgery. In ultrastructural studies we found the putatively regenerating axons within the lesion to be associated either with oligodendrocytes or Schwann cells, while other fibers were unmyelinated. Immunohistochemistry demonstrated that some of the regenerated fibers were tyrosine hydroxylase- or serotonin-immunoreactive, indicating a central origin. These findings suggest that there is a considerable amount of spontaneous regeneration after spinal cord lesions in rodents and that the fibers remain several months after injury. The findings of tyrosine hydroxylase- and serotonin-immunoreactivity in the axons suggest that descending central fibers contribute to this endogenous repair of ischemic spinal cord injury.

Effects of functional electrical stimulation training for six months on body composition and spasticity in motor complete tetraplegic spinal cord-injured individuals

The effect of functional electrical stimulation (FES) training on body composition, assessed by computed tomography, and the effect of spasticity, assessed by both objective and subjective measures, are evaluated. Fifteen motor-complete spinal-cord-injured men participated in the study. Eight of the 15 subjects undertook FES cycling 3 times weekly for 6 months. Whole body computed tomography scans evaluated changes in body composition. Simultaneous Modified Ashworth Scale and electromyography (EMG) measurements, resistive torque (Kin-Com) and EMG measurements, and self-ratings with Visual Analogue Scale during four consecutive days were used to evaluate changes in spasticity. Lower extremity muscle volume increased by an average of 1300 cm3 (p < 0.001) in the training group compared to the control group, who experienced no change. Otherwise no changes in body composition were seen. Significant correlations (Spearman) were found between individual EMG activity recordings and movement-provoked Modified Ashworth Scale ratings in 26% of the test situations, irrespective of group and time. The objective and subjective evaluation of movement-provoked passive (viscoelastic) and active (spasticity-related) resistance remained unchanged.

Solid human embryonic spinal cord xenografts in acute and chronic spinal cord cavities: a morphological and functional study

While therapeutic spinal cord grafting procedures are of interest in the chronic spinal cord injury stage, previous experimental grafting studies, including human spinal cord tissue, have mainly focused on the acute stage. Therefore, solid human embryonic spinal cord grafts were implanted in acute or chronic spinal cord aspiration cavities of immunodeficient rats to compare the morphological and locomotor outcome to that of lesion alone cases. Locomotor function was assessed using the Basso, Beattie, and Bresnahan open-field locomotor rating scale up to 6 months, while the morphological evaluation of graft survival, growth, and integration was performed at 6 weeks or 6 months after implantation. Graft survival was 94% in both lesion models, while graft growth was enhanced in the chronic compared to the acute cavity group. Human specific Thy-1 and neurofilament immunoreactive fibers were observed up to 7 mm into host white matter, while aminergic fibers were observed up to 1 mm into the grafts. Abundant calcitonin gene-related peptide immunoreactive fibers in the grafts in the absence both of immunoreactive cell bodies and colocalized human-specific neurofilament immunoreactivity, suggested host fiber ingrowth. At 6 months, the grafted cases presented less central canal deformation and lower glial fibrillary acidic protein immunoreactivity at the host cavity border compared to that of the nongrafted cases. The strong compensatory regain of locomotor function after unilateral spinal cord lesions was not affected by the human spinal cord grafts. In conclusion, solid human embryonic spinal cord tissue transplanted to a cavity in the adult injured spinal cord results in beneficial morphological effects in both the acute and chronic spinal cord lesion.

Expression of presenilin-1 and Notch-1 receptor in human embryonic CNS

In vitro studies have shown that the Alzheimer's disease-related presenilin-1 protein can mediate Notch-1 receptor cleavage during signalling. In the present study, we compared the distribution of presenilin-1 and Notch-1 receptor immunoreactivities in human embryonic CNS tissue during the first trimester of development. Our aim was to gain insight into whether these proteins are likely to interact functionally during human fetal brain development. CNS material was obtained from routine abortions, cryosectioned and studied by means of immunohistochemistry with antibodies to presenilin-1 and Notch-1. At very early stages of embryonic development (four to five gestational weeks) intensive presenilin-1 immunoreactivity could be seen predominantly in neurites in the ventral horn of the spinal cord, where it overlapped with 200-kDa neurofilament immunoreactivity. Presenilin-1 immunoreactivity was also seen in neuroblasts of the ventricular zone of the tel- and mesencephalon, as well as of the brainstem. Notch-1 receptor appeared in neuronal and ependymal cells throughout the CNS. Seven- to eight-week CNS tissue showed similar patterns of presenilin-1 and Notch-1 receptor expression in the spinal cord and cerebral cortex as was seen at five weeks. Both proteins were localised in the neuroepithelial cell layer lining the ventricles, as well as in the cortical plate layer, where immunoreactivity was seen in the cell bodies. In addition, presenilin-1 immunoreactivity was seen in thin neurites in the subplate of the developing cortex. At 10 weeks, presenilin-1 immunoreactivity was reduced in the spinal cord. These results show that, although presenilin-1 and Notch-1 receptor are localised to the same differentiating cell populations in the human cerebral cortex, making a direct interaction possible, these proteins are otherwise confined to different neurons or neuronal compartments, suggesting a role for presenilin-1 during early CNS differentiation that does not involve Notch-1 receptor processing. Double staining for presenilin-1 in the endoplasmic reticulum and presenilin-1 in the Golgi showed overlap to some extent in investigated CNS regions, but not in neurites. This suggests that presenilin-1 function during neurogenesis is not exclusively correlated to protein processing within the endoplasmic reticulum and Golgi, but that presenilin-1 may also be involved in other processes, such as axonal and dendritic outgrowth or synaptic formation. In summary, our findings provide supportive evidence that the presenilin-1 protein is involved in the development and maturation of the human fetal CNS. The presence of presenilin-1 immunoreactivity in both the cell bodies and neurites of developing neurons strongly suggests divergent mechanisms of function for presenilin-1 during human brain development. These may include interactions with any of the Notch receptor proteins, as well as Notch-independent mechanisms.

RANTES promotes growth and survival of human first-trimester forebrain astrocytes

We have examined the role of alpha and beta chemokines in the promotion of the ontogenetic development of the brain. RANTES was expressed preferentially in human fetal astrocytes in an age-dependent manner. Astrocytes from 5-week-old brains showed high proliferation and reduced survival, whereas 10-week-old astrocytes exhibited opposite effects. These effects were suppressed by anti-RANTES or anti-RANTES receptor antibodies and were enhanced by recombinant RANTES. RANTES induced tyrosine phosphorylation of several cellular proteins and nuclear translocation of STAT-1 in astrocytes. Interferon-gamma (IFN-gamma) was required for RANTES effects because RANTES induced IFN-gamma and only 10-week-old astrocytes expressed the IFN-gamma receptor. Blocking of IFN-gamma with antibody reversed the effects of RANTES, indicating that cytokine/chemokine networks are critically involved in brain development.

Functional connections are established in the deafferented rat spinal cord by peripherally transplanted human embryonic sensory neurons

Functionally useful repair of the mature spinal cord following injury requires axon growth and the re-establishment of specific synaptic connections. We have shown previously that axons from peripherally grafted human embryonic dorsal root ganglion cells grow for long distances in adult host rat dorsal roots, traverse the interface between the peripheral and central nervous system, and enter the spinal cord to arborize in the dorsal horn. Here we show that these transplants mediate synaptic activity in the host spinal cord. Dorsal root ganglia from human embryonic donors were transplanted in place of native adult rat ganglia. Two to three months after transplantation the recipient rats were examined anatomically and physiologically. Human fibres labelled with a human-specific axon marker were distributed in superficial as well as deep laminae of the recipient rat spinal cord. About 36% of the grafted neurons were double labelled following injections of the fluorescent tracers MiniRuby into the sciatic and Fluoro-Gold into the lower lumbar spinal cord, indicating that some of the grafted neurons had grown processes into the spinal cord as well as towards the denervated peripheral targets. Electrophysiological recordings demonstrated that the transplanted human dorsal roots conducted impulses that evoked postsynaptic activity in dorsal horn neurons and polysynaptic reflexes in ipsilateral ventral roots. The time course of the synaptic activation indicated that the human fibres were non-myelinated or thinly myelinated. Our findings show that growing human sensory nerve fibres which enter the adult deafferentated rat spinal cord become anatomically and physiologically integrated into functional spinal circuits.

Expression of interleukin-6 in human dorsal root ganglion cells

The expression of Interleukin-6 (IL-6) was studied in normal dorsal root ganglia (DRG) of juvenile and foetal humans, using immunohistochemistry and in situ hybridization techniques. There was an expression of IL-6-like immunoreactivity in more than 75% out of neuronal cells in the juvenile ganglia with a peripheral localization, and also an expression in the foetal ganglion cells. There was a co-localization of IL-6 with substance P (SP) and calcitonin gene-related peptide (CGRP) in more than 60% of the DRG cells, respectively. By in situ hybridization 0.9% of the cells in the juvenile ganglia and 1.1% of the cells in the foetal ganglia showed a positive signal for IL-6. In addition, expression of IL-6 was found in juvenile medulla spinalis, preferentially in the white matter.

Lingual BDNF and NT-3 mRNA expression patterns and their relation to innervation in the human tongue: similarities and differences compared with rodents

Brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT-3) mRNAs are expressed in developing and adult rodent tongue and are important for the proper development of lingual gustatory and somatosensory innervation in rodents. Here, we wished to determine whether the findings in rodents apply to humans. By using in situ hybridization histochemistry, distinct, specific, and in some instances overlapping patterns of BDNF and NT-3 mRNA expression were found in the developing and adult human tongue, gustatory papillae, and taste buds. BDNF mRNA was expressed in the superior surface epithelium of the developing fungiform papillae (i.e., developing taste buds), in the epithelium covering the circumvallate papillae, and in the subepithelial mesenchyme. Interestingly, BDNF mRNA was expressed in the lingual epithelium before nerve fibers reached the epithelium, indicating a prespecialization of the gustatory epithelium before the arrival of nerves. In the adult fungiform papillae, BDNF mRNA labeling was found in taste buds and in restricted areas in the non-gustatory lingual epithelium. NT-3 mRNA was found in the developing lingual epithelium and gustatory papillae. NT-3 mRNA labeling was observed in the adult fungiform taste buds, overlapping with BDNF mRNA labeling, in contrast to what was seen in rodents. NT-3 mRNA was additionally found in restricted areas in filiform papillae. Protein gene product 9.5 (PGP) antibodies were used to investigate a possible correlation between lingual innervation and sites of neurotrophin gene activity. Adult human tongue innervation differed from that of rodents, possibly in part due to a different neurotrophin expression pattern in the human tongue. Based on these findings, we suggest that BDNF and NT-3 are important for the initiation and maintenance of the gustatory and somatosensory innervation also in humans. The broader and somewhat overlapping expression patterns of BDNF and NT-3 mRNAs, compared with rodents, suggest additional and possibly somewhat overlapping roles for BDNF and NT-3 in the human tongue and also indicate differences between species. It is important that interspecies differences be taken into consideration.

Ionotropic glutamate receptor expression in human spinal cord during first trimester development

Quantitative receptor autoradiography and immunoblotting were used to study the expression and distribution of AMPA, kainate and NMDA receptors in first trimester human spinal cord obtained from elective abortions ranging from 4 to 11.5 weeks of gestational age. Spinal cord tissue sections were processed for receptor autoradiography with the ligands [3H]AMPA, [3H]kainate and [3H]MK-801 and the optical density was measured separately in a dorsal region (alar plate) and ventral region (basal plate) of the autoradiographs. Binding sites for all three ligands were demonstrated already at 4-5.5 weeks of gestation and increased continuously during the first trimester both in the dorsal and ventral regions. [3H]AMPA binding to both high- and low-affinity sites increased from undetectable levels to about 35 and 400 fmol/mg tissue, respectively, during this period. A temporal difference in the distribution of [3H]AMPA binding sites was observed. The early homogeneous pattern of [3H]AMPA binding in both alar and basal plates had changed to a heterogeneous pattern at 11 weeks of gestation with the highest density of [3H]AMPA binding sites in the superficial layers of the immature dorsal horn. [3H]kainate and [3H]MK-801 binding sites were densely and homogeneously distributed already at 4 weeks, and steadily increased six- and two-fold, respectively, to about 100 fmol/mg tissue at 11.5 weeks of gestation. Immunoreactive bands corresponding to the NMDA receptor subunits NR1, NR2A, NR2B, NR2C and NR2D were demonstrated by immunoblotting at the earliest between 4.5 and 7 weeks and increasing concentrations were seen up to 11 weeks of gestation. These results suggest that AMPA, kainate and NMDA receptors are expressed in the human spinal cord early in embryogenesis.

Spasticity after traumatic spinal cord injury: nature, severity, and location

OBJECTIVE

To assess spasticity in a prevalence population of persons with traumatic spinal cord injury (SCI), and determine the degree of correspondence between self-reported spasticity and investigator-elicited spasticity using the modified Ashworth scale.

DESIGN

Survey of a near total (88%) prevalence population.

SETTING

Outpatient clinic of a university hospital.

PATIENTS

A total of 354 individuals with SCI.

MAIN OUTCOME MEASURES

The survey includes self-reported symptoms, neurologic examination (American Spinal Injury Association [ASIA] classification), physical therapy examination, range of motion (ROM), and complications.

RESULTS

Presence of problematic spasticity was significantly correlated with cervical incomplete (ASIA B-D) injury. Reports of beneficial effects of spasticity were significantly less common in women. Self-reported problematic spasticity was significantly correlated with extensor spasticity. Spasticity was elicitable by movement provocation in 60% of the patients reporting spasticity. Significant correlations were found between elicitable spasticity and limited ROM.

CONCLUSION

Flexion, extension, and abduction movements performed with the patient placed in a standardized supine test position are suitable both for test of ROM and degree of spasticity. Spasticity was not elicitable by movement provocation on physical examination in 40% of the patients who reported spasticity, thus indicating that the patient's self-report is an important complement to the clinical assessment. A significant association between spasticity and contractures (reduced ROM) was seen.

Nerve growth factor-induced stimulation of dorsal root ganglion/spinal cord co-grafts in oculo: enhanced survival and growth of CGRP-immunoreactive sensory neurons

Intraocular co-grafts of rat fetal spinal cord and dorsal root ganglia were used to examine the enhanced survival, growth, and differentiation of sensory neurons by nerve growth factor. E14 lumbar spinal segments were implanted into the anterior eye chamber of capsaicin-pretreated rats. Two weeks later, an E14 dorsal root ganglion was implanted beside the spinal cord graft. Nerve growth factor or vehicle was injected weekly for 4 weeks into the anterior eye chamber. Co-grafts were examined weekly and, at 6 weeks, processed for calcitonin gene-related peptide (CGRP) immunofluorescence. No differences in overall size were determined for the grafts. Co-grafts treated with nerve growth factor contained many more CGRP neurons (19.4 cells/20 microm) that were significantly larger (mean 764 microm2) than neurons from control co-grafts (8.6 cells/20 microm; mean 373 microm2). In co-grafts treated with nerve growth factor, CGRP-immunoreactive fibers were extensive in the dorsal root ganglion, adjacent iris, and spinal cord compared to control co-grafts. A few CGRP-positive motoneurons were observed in the spinal cord, but no differences in number or size of motoneurons were found. The current report demonstrates that spinal cord and dorsal root ganglia can be co-grafted in oculo for long periods of time. Many dorsal root ganglion neurons survive and send peripheral processes into the iris and central processes into the spinal cord under the influence of exogenous nerve growth factor. The intraocular graft paradigm can be of use to further examine the role of neurotrophic factors in regulating or modulating dorsal root ganglion and spinal cord neurons.

In vitro expansion of a multipotent population of human neural progenitor cells

The isolation and expansion of human neural progenitor cells have important potential clinical applications, because these cells may be used as graft material in cell therapies to regenerate tissue and/or function in patients with central nervous system (CNS) disorders. This paper describes a continuously dividing multipotent population of progenitor cells in the human embryonic forebrain that can be propagated in vitro. These cells can be maintained and expanded using a serum-free defined medium containing basic fibroblast growth factor (bFGF), leukemia inhibitory factor (LIF), and epidermal growth factor (EGF). Using these three factors, the cell cultures expand and remain multipotent for at least 1 year in vitro. This period of expansion results in a 10(7)-fold increase of this heterogeneous population of cells. Upon differentiation, they form neurons, astrocytes, and oligodendrocytes, the three main phenotypes in the CNS. Moreover, GABA-immunoreactive and tyrosine hydroxylase-immunoreactive neurons can be identified. These results demonstrate the feasibility of long-term in vitro expansion of human neural progenitor cells. The advantages of such a population of neural precursors for allogeneic transplantation include the ability to provide an expandable, well-characterized, defined cell source which can form specific neuronal or glial subtypes.

Tyrosine kinases are required for IFN-gamma-induced growth of human embryonic forebrain astrocytes

The cytokine IFN-gamma was shown to regulate growth and differentiation of human embryonic forebrain astrocytes. This work investigated a signalling pathway used by IFN-gamma during the process of growth regulation of human fetal astrocytes obtained from first trimester embryos. IFN-gamma induced significantly higher cell survival compared to that of unexposed cultures, and this survival could be suppressed by incubation with the tyrosine protein kinase (TPK) specific inhibitor tyrphostin A47 at the non-toxic concentration of 10(-6) M. The signal transducer and activator of transcription (STAT)-1 was translocated into the nucleus upon IFN-gamma stimulation, which was also blocked by incubation with A47. Our data demonstrate that TPKs are actively involved in growth regulation of the developing brain astrocytes induced by IFN-gamma.

Lift/transfer and technical aids for persons with severe acquired brain injury. An inventory of problems

A questionnaire about assistive devices for lift and transfer was distributed to all individuals evaluated at the Solberga Project outpatient service unit, a regional centre for long-term follow-up of severely brain injured persons in the Greater Stockholm area. The target group was 60 severely brain injured adults, of whom 57 (30 women and 27 men) answered a questionnaire created by one of the authors. The causes of injury in the study population were trauma (n = 27), cerebrovascular accident (n = 19), anoxia (n = 10) and other (n = 1). Thirty-two persons were quadriplegic after the injury and 21 were hemiplegic. More than half (33/57) reported problems with all five defined lift and transfer situations. Most (42/44) reported problems getting in and out of their wheelchairs. Technical aids were seldom used; 24 persons did not use any aids at all. The most commonly used aid was an adjustable bed. Most of the technical aids were used when the individual also had personal assistance. The persons who managed lift and transfer by themselves used few aids. It is reasonable to assume that severely brain injured individuals would be involved in more activities if they used technical aids more readily.