Neurological disorders in a rural Western Australian population

BACKGROUND

There is limited information on the causes of neurological disorders in an Australian rural setting.

METHODS

This study reports on a prospective cohort of 160 patients (95 women and 65 men) with a mean age of 55.1 years (standard deviation 19.78 years, range 12-92 years) receiving a neurological work-up from one neurologist attending the Geraldton and Midwest region of Western Australia over a 12-month period.

RESULTS

Patients were divided into 15 diagnostic classifications. Movement disorders were the most common diagnostic classification (38 of 160 or 23.75%) and Parkinson's disease was the most common movement disorder (30 of 38 or 78.95%) with an estimated period of prevalence of 187.5 persons per 1000. Of the other neurological disorder diagnosis classifications the following number of patients per group was observed: epilepsy (27 or 16.87%); neuromuscular disorders (22 or 13.75%); multiple sclerosis (12 or 7.5%); cerebrovascular disease (10 or 6.25%); headaches (7 or 4.37%); neurodegenerative (7 or 4.37%); dementias (6 or 3.75%); memory dysfunction (6 or 3.75%); gait disorders (4 or 2.5%); vestibular syndrome (3 or 1.87%); pain syndrome (3 or 1.87%); sensory syndrome (2 or 1.25%); brain injury (1 or 0.62%) and miscellaneous (12 or 7.5%). A high number of persons having Parkinson's disease was found.

CONCLUSION

Possible risk factors for Parkinson's disease for individuals living in Geraldton and Midwest region need to be investigated. This study raises issues pertaining to the provision of services and allocation of resources in rural areas, especially for patients with Parkinson's disease.

Harnessing CD36 to rein in inflammation

Maintaining health requires a dynamic balance between the influence of pro-inflammatory and anti-inflammatory mediators. While inflammation serves an important protective role against infection, unrestrained inflammation is acutely lethal and unresolved inflammation contributes to a broad range of chronic disorders. Immunotherapy with cytokines themselves or cytokine antagonists faces strict limitations due to efficacy, safety and cost. More successful treatment of the pro-inflammatory component of chronic disorders may emerge from strategies designed to reset the balance between pro and anti-inflammatory cytokines through physiological regulatory pathways. One emerging avenue for this approach is exploitation of the link between the cell surface protein CD36 and the anti-inflammatory cytokine interleukin-10 (IL-10). Agents that increase CD36 expression and agents that directly bind to CD36 have anti-inflammatory properties that may directly relate to induction of IL-10. The immunosuppressive effects of apoptotic cells were first reported more than a decade ago and have since been tested in animal models and several clinical trials. A recent publication demonstrates that induction of IL-10 by apoptotic cells is largely dependent upon the interaction between apoptotic cells and CD36, the receptor on monocytes and macrophages for apoptotic cells. This provides a direct mechanistic link between CD36 engagement and IL-10 induction, opening up new possibilities for using CD36 ligands, agents that increase CD36 expression or a combination of both to modulate inflammation and treat, or even prevent, an important set of chronic disorders.

XMODULATION IN MICEAND MEN: IL-10 PRODUCING CELLS INBLOOD AND LYMPHOID TISSUE

Background: The human immune system provides remarkable protection from a plethora of pathogens, but can cause damage when activated for a prolonged time (as inpersistent infections) or against self (autoimmunity). Therefore, mechanisms of immune system downregulation and control are imperative. There is little data on how the immune system is controlled in healthy individuals. We recently described a novel population of white blood cells that constitutively produce the immunomodulatory cytokine interleukin-10 (IL-10). Our objective was to further delineate the distribution of these cells in human and mouse models, as well as potential triggers for interleukin-10 production in vitro. Methods: Human and animal protocols were reviewed and approved by the institutional ethics board and animal care facilities, and informed consent was obtained from all human donors. The ex vivo percentage of peripheral blood CD36^+IL-10^+ mononuclear cells was assessed by intracellular flow cytometry in 10 healthy individuals. IL-10 production after exposure to twoCD36 ligands, thrombospondin and oxidized low density lipoprotein (oxLDL) was measured at 8 hours. Peripheral blood mononuclear cells and splenocytes from BL/6 (n=5) and Balb/c (n=1) micewere assessed for CD36^+IL-10^+ cells ex vivo as well. Results: The percentage of CD36^+IL-10^+ cells in peripheral blood fromhealthy individuals ranges between 0.1% and 0.9%. The percentage was similar in mouse peripheral blood, with a range of 0.4%-1.1%. These cells were also found in mouse spleen at a higher frequency than peripherally (1.1-1.5%). Human CD36^+IL-10^+ cells have more IL-10 when exposed to thrombospondin, oxLDL. Conclusions: Our novel population of IL-10 producing cells is found not only in healthy humans, but also in lymphoid tissue and blood from pathogen free mice. This highlights the evolutionary conservation of the cell across species, and suggests an important homeostatic function. The physiologic ligands for CD36 are ubiquitous in circulation, and ourin vitro data suggests a link between CD36 ligation and IL-10 production. IL-10 is a known immune system modulator, and its production by these cells may help maintain homeostaticcontrol of the immune system.

The character of anti-HCV T cell responses differs between spontaneous and treatment-induced viral clearance s

Introduction: Hepatitis C virus (HCV) is a common infection with approximately 170 million individuals infected worldwide. The majority of exposed individuals develop chronic infection, with viral clearance being the exception to the rule. Even with antiviral therapy, only 50-75% of treated individuals become HCV RNA negative. The role of the adaptive immune response, and particularly T cells, has been well established in other viral infections but its function in HCV infection is unclear, making it difficult to develop either prophylactic or therapeutic vaccine strategies. Objectives: Compare the breadth, specificity, and magnitude of anti-HCV T cell responses in individuals who are chronically HCV-infected with those who clear HCV spontaneously or after antiviral treatment. Methods: We assessed T cell responses in 3 groups of HCV exposed individuals: 18 people who were chronically HCV infected (anti-HCV antibody and HCV RNA positive), 5 who were exposed to HCV but cleared the virus without treatment (antibody positive, RNA negative), and 17 who responded to anti-HCV treatment (antibody positive but RNA negative after treatment). CD4+ T cell responses to HCV and recall antigens were measured by standard 3H-thymidine proliferation assay, and CD8+ T cell responses were evaluated by incubating peripheral blood mononuclear cells (PBMC) overnight with 15-mer peptides spanning the entire HCV-1a genome. The number of HCV-specific interferon-gamma (IFN-g)-producing cells per million PBMC was estimated by ELISPOT. Results: Anti-HCV CD4+ T cell responses were uncommon, and of low magnitude in all groups. Responses were only to peptides in the core region. The overall breadth of the anti-HCV CD8+ response was greatest in treated responders (average 43/44 peptide pools tested positive) and least in those who failed treatment (average 11/44). All clearers had responses to the NS5 region. The magnitude of the CD8+ response tended to be highest in the treated responders, but there was no significant difference between groups. Conclusions: The character of the anti-HCV T cell response differs not just between chronic infection and clearance, but also between spontaneous versus treatment-associated HCV clearance. This suggests that it is likely a combination of T cell breadth, magnitude and specificity that results in viral clearance. Based on these results, development of therapeutic and prophylactic vaccine strategies may need to target different T cell responses.

Population structure and habitat use of baboons (Papio hamadryas ursinus) in the Blyde Canyon Nature Reserve

Baboons are highly intelligent and ecologically flexible animals with attributes that allow them to exploit diverse habitats. As a result of their dietary flexibility they often exploit human habitats, causing damage to crops and forest plantations as well as to human dwellings. In the South African context this has led to baboons being regarded as problem animals and attempted extirpation is the most common approach to the damage they cause. This perception of and attitude toward baboons gives many conservationists cause for concern since all southern African cercopithecine primates are CITES listed and it has not been proven that this strategy is the best long-term solution. As part of a research programme focusing on the damage done by chacma baboons in pine plantations along the Drakensberg escarpment in Mpumalanga, a single troop in the Blyde Canyon Nature Reserve was studied to describe their patterns of habitat use. Vegetation and habitat surveys were conducted within the home range of the troop. The troop was habituated and each member’s activity, location and food items utilised were recorded over a 12 month period. The results of this study indicate that baboons utilised plant communities based on food production and availability rather than size in hectares. The results also indicate that the group size, foraging and food search strategies of this troop resembles that of the Drakensberg troops previously studied. The study troop employs two different forage modes of engagement depending on where they choose to forage while they avoid utilising an easily accessible pine plantation. Due to the troop’s long inter-birth intervals it is likely that the current forestry practice of extirpation may have a negative influence on baboon population viability in these areas.

Prostaglandin E2 receptor EP4 contributes to inflammatory pain hypersensitivity

Prostaglandin E(2) (PGE(2)) is both an inflammatory mediator released at the site of tissue inflammation and a neuromodulator that alters neuronal excitability and synaptic processing. The effects of PGE(2) are mediated by four G-protein-coupled EP receptors (EP1-EP4). Here we show that the EP4 receptor subtype is expressed by a subset of primary sensory dorsal root ganglion (DRG) neurons, and that its levels, but not that of the other EP1-3 subtypes, increase in the DRG after complete Freund' adjuvant-induced peripheral inflammation. Administration of both an EP4 antagonist [AH23848, (4Z)-7-[(rel-1S,2S,5R)-5-((1,1'-biphenyl-4-yl)methoxy)-2-(4-morpholinyl)-3-oxocyclopentyl]-4-heptenoic acid] and EP4 knockdown with intrathecally delivered short hairpin RNA attenuates inflammation-induced thermal and mechanical behavioral hypersensitivity, without changing basal pain sensitivity. AH23848 also reduces the PGE(2)-mediated sensitization of capsaicin-evoked currents in DRG neurons in vitro. These data suggest that EP4 is a potential target for the pharmacological treatment of inflammatory pain.

Primary sciatic nerve lymphoma: a case report and review of the literature

A patient with primary B cell non-Hodgkin's lymphoma of the sciatic nerve is described. He presented with neuropathic symptoms in the left leg, initially diagnosed as tarsal tunnel syndrome. Magnetic resonance imaging (MRI) identified the abnormality in the sciatic nerve. A fascicular biopsy of the sciatic nerve showed a diffuse large B cell non-Hodgkin's lymphoma. The patient was treated with chemotherapy and rituximab (anti-CD20 monoclonal antibody). Four months later he was in remission, and remains so 48 months from presentation. Primary lymphoma of single peripheral nerves may be a unique subtype of extranodal lymphoma, which usually follows an aggressive course and has a variable response to current therapeutic strategies. MRI is useful, alongside electrophysiological studies, in patients with atypical peripheral nerve symptoms.

Vegetation classification as the basis for baboon management in the Bourke’s Luck Section of the Blyde Canyon Nature Reserve, Mpumalanga

The Blyde Canyon Nature Reserve (BCNR) was identified as an important conservation area due to of its extraordinary diversity of plant species. Plant communities represent ecosystems and form the basis of any management plan for natural areas. If these ecosystems and their different potentials are unknown, they cannot be managed successfully. Baboons exploit diverse habitats including human environments where they often cause damage to crops and forest plantations. Baboons are regarded as particularly problematic residents of protected areas as conventional fences do not readily enclose them, their eclectic diets allow them to benefit from a range of agricultural endeavours, and they are behaviourally opportunistic. Thus as a first step to implementing a conservation policy to manage chacma baboons in the BCNR, it was necessary to have some understanding of their exploitation of natural habitats adjacent to areas where they do cause problems. Although a broad vegetation map of the BCNR exists, no detailed vegetation studies have been conducted on the largest part of the reserve. It was therefore decided to ndertake a detailed vegetation study of the home range of a single baboon troop within the Bourke’s Luck section of the BCNR. From a TWINSPAN classification, refined by Braun-Blanquet procedures, 13 plant communities, which can be grouped into seven major groups, were identified. A classification and description of these communities, as well as a vegetation map are presented. Data collected as part of this study also revealed that the baboons show preference to certain communities whilst avoiding others. These have important consequences in terms of the management strategies followed on the reserve.

RNA splicing capability of live neuronal dendrites

Dendrites are specialized extensions of the neuronal soma that contain components of the cellular machinery involved in RNA and protein metabolism. Several dendritically localized proteins are associated with the precursor-mRNA (pre-mRNA) splicing complex, or spliceosome. Although some spliceosome-related, RNA-binding proteins are known to subserve separate cytoplasmic functions when moving between the nucleus and cytoplasm, little is known about the pre-mRNA splicing capacity of intact dendrites. Here, we demonstrate the presence and functionality of pre-mRNA-splicing components in dendrites. When isolated dendrites are transfected with a chicken delta-crystallin pre-mRNA or luciferase reporter pre-mRNA, splicing junctions clustered at or near expected splice sites are observed. Additionally, in vitro synaptoneurosome experiments show that this subcellular fraction contains a similar complement of splicing factors that is capable of splicing chicken delta-crystallin pre-mRNA. These observations suggest that pre-mRNA-splicing factors found in the dendroplasm retain the potential to promote pre-mRNA splicing.

Habitual cave use and thermoregulation in chacma baboons (Papio hamadryas ursinus)

The willingness to utilise caves as shelters is held to have been important to early humans but dependent on pyrotechnology. Despite anecdotal evidence that non-human primates will also exploit caves there has as yet been no detailed account of such exploitation or of the reasons underlying it. Here we provide the first such data, on the frequency and patterning of the use of an underground cave system by baboons (Papio hamadryas)-and show that usage is determined, at least in part, by above-ground temperatures.

Gene therapy for central nervous system repair

The amelioration of the sequelae of CNS injury by gene therapy requires three post-injury events to be addressed: scarring, neuron death and axon regeneration. Administering anti-apoptotic, and axon growth promoting genes to neurons is inefficient, using nonviral vectors, because access to the transcriptional machinery is restricted by an intact nuclear membrane in G0 cells. Viral vectors have better transfection rates but a higher incidence of deleterious effects than non-viral vectors. Discrete targeted transfection of astrocytes, for example, about the wound with antifibrotic genes is essential to control scarring and for the inhibition of axon growth locally by gene products without transfecting neighboring and distant cells. Either rational or forced evolutionary design of vectors will ultimately achieve efficient safe gene transduction. Recombinant protein treatments for CNS repair have proved disappointing, probably because axotomized neurons are difficult to access in multiple disparate sites in the CNS after penetrant injury. Gene therapy has the potential to overcome these difficulties since sustained antiscarring/neurotrophic regimes are achievable after a single delivery to the site of injury by uptake by local injury responsive cells in the wound, and by axon terminals. Subsequent retrograde axonal transport delivers the therapeutic genes to all axotomized neurons throughout the CNS.

Sustained effects of gene-activated matrices after CNS injury

We show that when gene-activated matrices (GAM) are placed between the proximal and distal stumps of severed rat optic nerves, DNA is retained within the GAM, promoting sustained transgene expression in the optic nerve, in the GAM itself, and, more importantly, in axotomized retinal ganglion cells (RGC). Plasmids that encode basic fibroblast growth factor (FGF2), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT3) promote sustained survival of RGC for over 3 months after the initial injury. These findings suggest that immobilized DNA implanted into a CNS lesion will be delivered by axon terminal uptake and retrograde transport to axotomized neurons. GAM may therefore be a useful agent for promoting sustained neuron survival and axon regeneration. Whether further optimization of the matrices, plasmids, promoters, and genes present in the GAM will promote even more survival or, alternatively, axon regeneration remains to be determined.

Siblings with development delay, mild spasticity and subcortical cysts: a further leukoencephalopathy?

We present a family with mild neurological symptoms and intra-cerebral subcortical cysts on magnetic resonance imaging (MRI). Common clinical features are microcephaly, learning difficulties, spasticity, dyspraxia and restricted movements of the neck and shoulder. The family has features in common with vacuolating leukoencephalopathy of van de Knaap and Olivier and may represent a new variant.

Inner city disadvantage and family functioning

The co-existence of types of social, environmental and family disadvantage and domains of family dysfunction is explored through individual interviews and use of the Family Assessment Device in a cross-sectional study of 143 inner city families. The dependence upon social welfare by the family and the overall degree of disadvantage experienced both correlate significantly with all forms of family dysfunction. Marital disruption, poor physical care of the home or of the child(ren) and poor quality of mothering correlate significantly with difficulties both in role allocation and in affective involvement. Those families suffering more types of environmental disadvantage are more likely also to be dysfunctional in each domain of family life. Some possible mechanisms for these associations are highlighted and their implications for planning of effective interventions discussed.

Seroprevalence and seroincidence of Norwalk-like virus infection among Brazilian infants and children

To determine the importance of Norwalk-like viruses (NLVs) as pediatric pathogens in a developing country, the seroprevalence and seroincidence of this group of viruses in a cohort of children less than 4 years of age in an urban shantytown in northeastern Brazil was examined. Serum samples were collected approximately every 6 months from 135 children who were surveyed three times each week for diarrhea and vomiting. NLV IgG was measured by an enzyme immunosorbent assay (EIA) with recombinant Norwalk virus capsid protein. Overall NLV seroprevalence was 71%, and the overall NLV seroconversion rate was 0.7 seroconversions per child-year. The highest age-specific NLV seroconversion rate (0.8 seroconversions per child-year) was observed in the 13-24-month age group. For all study children, the incidence of diarrhea and vomiting was significantly greater (P < 0.01) during time periods spanned by serum pairs that indicated NLV seroconversion compared with time periods without NLV seroconversion. However, NLV seroconversion was not associated with gastrointestinal symptoms during the first year of life.

Mechanisms and impact of enteric infections

The increased recognition of both old and new enteric pathogens and their potential impact requires an improved understanding of pathogenesis and effective interventions. While the overwhelming mortality (> 3 million children per year) due to diarrheal diseases is well-recognized, the potential long-term impacts of enteric infections and early childhood diarrhea morbidity are just beginning to be appreciated. Furthermore, several enteric infections are now being recognized as causes of growth shortfalls with or without diarrhea; i.e., malnutrition may be one of the greatest yet of the "emerging infectious diseases." The increased appreciation of this extended impact calls for further quantification and improved understanding of the deranged physiology. In particular, persistent diarrheal illnesses exhibit common themes of blunted villi, disruption of intestinal barrier function and varying degrees of sub-mucosal inflammation for which lactulose/mannitol permeability and fecal lactoferrin provide respective quantification. Finally, such improved understanding will allow targeted interventions among those most vulnerable, which will enable further documentation of cost effectiveness and the potential for improved human development which is critical to reducing the widening disparity and population overgrowth which increasingly threaten our global security.

Female baboons do not raise the stakes but they give as good as they get

We used data from four chacma baboon, Papio cynocephalus ursinus, troops, living in two populations, to test the raise the stakes (RTS) strategy of reciprocity. Female baboons did not raise the stakes either within or across grooming bouts. Instead they time-matched grooming contributions and divided grooming into short episodes. In addition, analysis of the grooming behaviour of frequently versus infrequently grooming dyads did not reveal differences in grooming patterns predicted by the RTS strategy. We suggest time constraints preclude the escalation of grooming bout length as required by RTS; the data were more consistent with a strategy of give as good as you get. However, this strategy could not explain all the patterns observed, and we conclude that biological market theory represents a more appropriate framework for investigating female grooming dynamics than dyadic games based on the iterated prisoner's dilemma. We suggest that competitive altruism among individuals acts as a market force influencing an individual's value as a grooming partner. Copyright 2000 The Association for the Study of Animal Behaviour.