Selective loss of noradrenaline exacerbates early cognitive dysfunction and synaptic deficits in APP/PS1 mice.

Background: Degeneration of the locus coeruleus (LC), the major noradrenergic nucleus in the brain, occurs early and is ubiquitous in Alzheimer’s disease (AD). Experimental lesions to the LC exacerbate AD-like neuropathology and cognitive deficits in several transgenic mouse models of AD. Because the LC contains multiple neuromodulators known to affect amyloid toxicity and cognitive function, the specific role of noradrenaline (NA) in AD is not well understood. Methods: To determine the consequences of selective NA deficiency in an AD mouse model, we crossed dopamine -hydroxylase (DBH) knockout mice with amyloid precursor protein (APP)/presenilin-1 (PS1) mice overexpressing mutant APP and PS1. Dopamine -hydroxylase (/) mice are unable to synthesize NA but otherwise have normal LC neurons and co-transmitters. Spatial memory, hippocampal long-term potentiation, and synaptic protein levels were assessed. Results: The modest impairments in spatial memory and hippocampal long-term potentiation displayed by young APP/PS1 or DBH (/) single mutant mice were augmented in DBH (/)/APP/PS1 double mutant mice. Deficits were associated with reduced levels of total calcium/calmodulin-dependent protein kinase II and N-methyl-D-aspartate receptor 2A and increased N-methyl-D-aspartate receptor 2B levels and were independent of amyloid accumulation. Spatial memory performance was partly improved by treatment with the NA precursor drug L-threo-dihydroxyphenylserine. Conclusions: These results indicate that early LC degeneration and subsequentNAdeficiency inADmay contribute to cognitive deficits via altered levels of calcium/calmodulin-dependent protein kinase II and N-methyl-D-aspartate receptors and suggest that NA supplementation could be beneficial in early AD

The frequency of transforming growth factor-TGF-B gene polymorphisms in a normal southern Iranian population

Several single nucleotide polymorphisms (SNPs) of the transforming growth factor-β1 gene (TGFB1) have been reported. Determination of TGFB1 SNPs allele frequencies in different ethnic groups is useful for both population genetic analyses and association studies with immunological diseases. In this study, five SNPs of TGFB1 were determined in 325 individuals from a normal southern Iranian population using polymerase chain reaction-restriction fragment length polymorphism method. This population was in Hardy-Weinberg equilibrium for these SNPs. Of the 12 constructed haplotypes, GTCGC and GCTGC were the most frequent in the normal southern Iranian population. Comparison of genotype and allele frequencies of TGFB SNPs between Iranian and other populations (meta-analysis) showed significant differences, and in this case the southern Iranian population seems genetically similar to Caucasoid populations. However, neighbour-joining tree using Nei's genetic distances based on TGF-β1 allele frequencies showed that southern Iranians are genetically far from people from the USA, Germany, UK, Denmark and the Czech Republic. In conclusion, this is the first report of the distribution of TGFB1 SNPs in an Iranian population and the results of this investigation may provide useful information for both population genetic and disease studies. © 2008 The Authors

The multiple sclerosis risk sharing scheme monitoring study - early results and lessons for the future

Background: Risk sharing schemes represent an innovative and important approach to the problems of rationing and achieving cost-effectiveness in high cost or controversial health interventions. This study aimed to assess the feasibility of risk sharing schemes, looking at long term clinical outcomes, to determine the price at which high cost treatments would be acceptable to the NHS. Methods: This case study of the first NHS risk sharing scheme, a long term prospective cohort study of beta interferon and glatiramer acetate in multiple sclerosis ( MS) patients in 71 specialist MS centres in UK NHS hospitals, recruited adults with relapsing forms of MS, meeting Association of British Neurologists (ABN) criteria for disease modifying therapy. Outcome measures were: success of recruitment and follow up over the first three years, analysis of baseline and initial follow up data and the prospect of estimating the long term cost-effectiveness of these treatments. Results: Centres consented 5560 patients. Of the 4240 patients who had been in the study for a least one year, annual review data were available for 3730 (88.0%). Of the patients who had been in the study for at least two years and three years, subsequent annual review data were available for 2055 (78.5%) and 265 (71.8%) patients respectively. Baseline characteristics and a small but statistically significant progression of disease were similar to those reported in previous pivotal studies. Conclusion: Successful recruitment, follow up and early data analysis suggest that risk sharing schemes should be able to deliver their objectives. However, important issues of analysis, and political and commercial conflicts of interest still need to be addressed

Widespread sex differences in gene expression and splicing in the adult human brain

There is strong evidence to show that men and women differ in terms of neurodevelopment, neurochemistry and susceptibility to neurodegenerative and neuropsychiatric disease. The molecular basis of these differences remains unclear. Progress in this field has been hampered by the lack of genome-wide information on sex differences in gene expression and in particular splicing in the human brain. Here we address this issue by using post-mortem adult human brain and spinal cord samples originating from 137 neuropathologically confirmed control individuals to study whole-genome gene expression and splicing in 12 CNS regions. We show that sex differences in gene expression and splicing are widespread in adult human brain, being detectable in all major brain regions and involving 2.5% of all expressed genes. We give examples of genes where sex-biased expression is both disease-relevant and likely to have functional consequences, and provide evidence suggesting that sex biases in expression may reflect sex-biased gene regulatory structures

Gpr37l1 Modulates Seizure Susceptibility: Evidence from Mouse Studies and Analyses of a Human Gpr37l1 Variant

Progressive myoclonus epilepsies (PMEs) are disorders characterized by myoclonic and generalized seizures with progressive neurological deterioration. While several genetic causes for PMEs have been identified, the underlying causes remain unknown for a substantial portion of cases. Here we describe several affected individuals from a large, consanguineous family presenting with a novel PME in which symptoms begin in adolescence and result in death by early adulthood. Whole exome analyses revealed that affected individuals have a homozygous variant in GPR37L1 (c.1047G \u3e T [Lys349Asn]), an orphan G protein-coupled receptor (GPCR) expressed predominantly in the brain. In vitro studies demonstrated that the K349N substitution in Gpr37L1 did not grossly alter receptor expression, surface trafficking or constitutive signaling in transfected cells. However, in vivo studies revealed that a complete loss of Gpr37L1 function in mice results in increased seizure susceptibility. Mice lacking the related receptor Gpr37 also exhibited an increase in seizure susceptibility, while genetic deletion of both receptors resulted in an even more dramatic increase in vulnerability to seizures. These findings provide evidence linking GPR37L1 and GPR37 to seizure etiology and demonstrate an association between a GPR37L1 variant and a novel progressive myoclonus epilepsy

Coordination of opposing sex-specific and core muscle groups regulates male tail posture during Caenorhabditis elegans male mating behavior

Background To survive and reproduce, animals must be able to modify their motor behavior in response to changes in the environment. We studied a complex behavior of Caenorhabditis elegans, male mating behavior, which provided a model for understanding motor behaviors at the genetic, molecular as well as circuit level. C. elegans male mating behavior consists of a series of six sub-steps: response to contact, backing, turning, vulva location, spicule insertion, and sperm transfer. The male tail contains most of the sensory structures required for mating, in addition to the copulatory structures, and thus to carry out the steps of mating behavior, the male must keep his tail in contact with the hermaphrodite. However, because the hermaphrodite does not play an active role in mating and continues moving, the male must modify his tail posture to maintain contact. We provide a better understanding of the molecular and neuro-muscular pathways that regulate male tail posture during mating. Results Genetic and laser ablation analysis, in conjunction with behavioral assays were used to determine neurotransmitters, receptors, neurons and muscles required for the regulation of male tail posture. We showed that proper male tail posture is maintained by the coordinated activity of opposing muscle groups that curl the tail ventrally and dorsally. Specifically, acetylcholine regulates both ventral and dorsal curling of the male tail, partially through anthelmintic levamisole-sensitive, nicotinic receptor subunits. Male-specific muscles are required for acetylcholine-driven ventral curling of the male tail but dorsal curling requires the dorsal body wall muscles shared by males and hermaphrodites. Gamma-aminobutyric acid activity is required for both dorsal and ventral acetylcholine-induced curling of the male tail and an inhibitory gamma-aminobutyric acid receptor, UNC-49, prevents over-curling of the male tail during mating, suggesting that cross-inhibition of muscle groups helps maintain proper tail posture. Conclusion Our results demonstrated that coordination of opposing sex-specific and core muscle groups, through the activity of multiple neurotransmitters, is required for regulation of male tail posture during mating. We have provided a simple model for regulation of male tail posture that provides a foundation for studies of how genes, molecular pathways, and neural circuits contribute to sensory regulation of this motor behavior

New onset neuromyelitis optica in a young Nigerian woman with possible antiphospholipid syndrome: a case report

<p>Abstract</p> <p>Introduction</p> <p>Devic's neuromyelitis optica is an inflammatory demyelinating disease that targets the optic nerves and spinal cord. It has a worldwide distribution and distinctive features that distinguish it from multiple sclerosis. There has been no previous report of neuromyelitis optica from our practice environment, and we are not aware of any case associated with antiphospholipid syndrome in an African person.</p> <p>Case presentation</p> <p>We report the case of a 28-year-old Nigerian woman who presented with neck pain, paroxysmal tonic spasms, a positive Lhermitte's sign and spastic quadriplegia. She later developed bilateral optic neuritis and had clinical and biochemical features of antiphospholipid syndrome. Her initial magnetic resonance imaging showed a central linear hyperintense focus in the intramedullary portion of C2 to C4. Repeat magnetic resonance imaging after treatment revealed resolution of the signal intensity noticed earlier.</p> <p>Conclusion</p> <p>Neuromyelitis optica should be considered in the differential diagnoses of acute myelopathy in Africans. We also highlight the unusual association with antiphospholipid syndrome. Physicians should screen such patients for autoimmune disorders.</p

Aquaporin-4 and myelin oligodendrocyte glycoprotein antibodies in immune-mediated optic neuritis at long-term follow-up

OBJECTIVES: To re-evaluate serum samples from our 2007 cohort of patients with single-episode isolated ON (SION), recurrent isolated ON (RION), chronic relapsing inflammatory optic neuropathy (CRION), multiple sclerosis-associated ON (MSON) and neuromyelitis optica (NMO). METHODS: We re-screened 103/114 patients with available serum on live cell-based assays (CBA) for aquaporin-4 (AQP4)-M23-IgG and myelin-oligodendrocyte glycoprotein (MOG)-α1-IgG. Further testing included oligoclonal bands, serum levels of glial fibrillar acidic and neurofilament proteins and S100B. We show the impact of updated serology on these patients. RESULTS: Reanalysis of our original cohort revealed that AQP4-IgG seropositivity increased from 56% to 75% for NMO, 5% to 22% for CRION, 6% to 7% for RION, 0% to 7% for MSON and 5% to 6% for SION. MOG-IgG1 was identified in 25% of RION, 25% of CRION, 10% of SION, 0% of MSON and 0% of NMO. As a result, patients have been reclassified incorporating their autoantibody status. Presenting visual acuity was significantly worse in patients who were AQP4-IgG seropositive (p=0.034), but there was no relationship between antibody seropositivity and either ON relapse rate or visual acuity outcome. CONCLUSIONS: The number of patients with seronegative CRION and RION has decreased due to improved detection of autoantibodies over the past decade. It remains essential that the clinical phenotype guides both antibody testing and clinical management. Careful monitoring of the disease course is key when considering whether to treat with prophylactic immune suppression

Placebo-controlled study in neuromyelitis optica : ethical and design considerations

BACKGROUND: To date, no treatment for neuromyelitis optica (NMO) has been granted regulatory approval, and no controlled clinical studies have been reported. OBJECTIVE: To design a placebo-controlled study in NMO that appropriately balances patient safety and clinical-scientific integrity. METHODS: We assessed the "standard of care" for NMO to establish the ethical framework for a placebo-controlled trial. We implemented measures that balance the need for scientific robustness while mitigating the risks associated with a placebo-controlled study. The medical or scientific community, patient organizations, and regulatory authorities were engaged early in discussions on this placebo-controlled study, and their input contributed to the final study design. RESULTS: The N-MOmentum study (NCT02200770) is a clinical trial that randomizes NMO patients to receive MEDI-551, a monoclonal antibody that depletes CD19+ B-cells, or placebo. The study design has received regulatory, ethical, clinical, and patient approval in over 100 clinical sites in more than 20 countries worldwide. CONCLUSION: The approach we took in the design of the N-MOmentum trial might serve as a roadmap for other rare severe diseases when there is no proven therapy and no established clinical development path

Differential diagnosis of suspected multiple sclerosis: a consensus approach

BACKGROUND AND OBJECTIVES: Diagnosis of multiple sclerosis (MS) requires exclusion of diseases that could better explain the clinical and paraclinical findings. A systematic process for exclusion of alternative diagnoses has not been defined. An International Panel of MS experts developed consensus perspectives on MS differential diagnosis. METHODS: Using available literature and consensus, we developed guidelines for MS differential diagnosis, focusing on exclusion of potential MS mimics, diagnosis of common initial isolated clinical syndromes, and differentiating between MS and non-MS idiopathic inflammatory demyelinating diseases. RESULTS: We present recommendations for 1) clinical and paraclinical red flags suggesting alternative diagnoses to MS; 2) more precise definition of "clinically isolated syndromes" (CIS), often the first presentations of MS or its alternatives; 3) algorithms for diagnosis of three common CISs related to MS in the optic nerves, brainstem, and spinal cord; and 4) a classification scheme and diagnosis criteria for idiopathic inflammatory demyelinating disorders of the central nervous system. CONCLUSIONS: Differential diagnosis leading to MS or alternatives is complex and a strong evidence base is lacking. Consensus-determined guidelines provide a practical path for diagnosis and will be useful for the non-MS specialist neurologist. Recommendations are made for future research to validate and support these guidelines. Guidance on the differential diagnosis process when MS is under consideration will enhance diagnostic accuracy and precision