[Show abstract][Hide abstract] ABSTRACT: Late Epstein-Barr virus infection and hypovitaminosis-D as environmental risk factors in the pathogenesis of multiple sclerosis are gaining great interest. We, therefore, tested for in-vivo interdependence between Epstein-Barr-virus (EBV)-status and 25-hydroxyvitamin D3 (25(OH)D3) -level in healthy young individuals from a United Kingdom (UK) autumn cohort. EBV-load was measured by quantitative polymerase chain reaction and 25(OH)D3 levels by isotope-dilution liquid chromatography-tandem mass spectrometry. This young, healthy UK autumn cohort showed surprisingly low levels of 25(OH)D3 (mean value: 40.5 nmol/L ± 5.02). Furthermore, we found that low 25(OH)D3 levels did not impact on EBV load and anti-EBV nuclear antigen-1 (EBNA-1) titers. However, we observed a correlation between EBV load and EBNA-1 titers. These observations should be of value in the study of the potential relationship between hypovitaminosis-D and EBV-status in the pathophysiology of multiple sclerosis.
[Show abstract][Hide abstract] ABSTRACT: The potential to use Schwann cells (SCs) in neural repair for patients suffering from neurotrauma and neurodegenerative diseases is well recognized. However, significant cell death after transplantation hinders the clinical translation of SC-based therapies. Various factors may contribute to the death of transplanted cells. It is known that prolonged activation of P2X7 purinoceptors (P2X7R) can lead to death of certain types of cells. In this study, we show that rat SCs express P2X7R and exposure of cultured SCs to high concentrations of ATP (3-5 mM) or a P2X7R agonist, 2'(3')-O-(4-benzoylbenzoyl)ATP (BzATP) induced significant cell death rapidly. High concentrations of ATP and BzATP increased ethidium uptake by SCs, indicating increased membrane permeability to large molecules, a typical feature of prolonged P2X7R activation. SC death, as well as ethidium uptake, induced by ATP was blocked by an irreversible P2X7R antagonist oxidized ATP (oxATP) or a reversible P2X7R antagonist A438079. oxATP also significantly inhibits the increase of intracellular free calcium induced by minimolar ATP concentrations. Furthermore, ATP did not cause death of SCs isolated from P2X7R-knockout mice. All these results suggest that P2X7R is responsible for ATP-induced SC death in vitro. When rat SCs were treated with oxATP before transplantation into uninjured rat spinal cord, 35% more SCs survived than untreated SCs 1 week after transplantation. Moreover, 58% more SCs isolated from P2X7R-knockout mice survived after being transplanted into rat spinal cord than SCs from wild-type mice. This further confirms that P2X7R is involved in the death of transplanted SCs. These results indicate that targeting P2X7R on SCs could be a potential strategy to improve the survival of transplanted cells. As many other types of cells, including neural stem cells, also express P2X7R, deactivating P2X7R may improve the survival of other types of transplanted cells.
[Show abstract][Hide abstract] ABSTRACT: Nogo receptor 1 (NgR1) mediates the inhibitory effects of the several myelin-associated inhibitors (MAIs) on axonal regeneration in the central nervous system. A truncated soluble NgR1 (sNgR) has been reported to act as a decoy receptor to block the actions of MAIs. In this study, we fused the sNgR to nerve growth factor (NGF) and used NGF as a carrier to deliver sNgR to the intercellular space to neutralize MAIs. NGF in NGF-sNgR remained biologically active and induced sprouting of calcitonin gene related peptide containing axons when expressed in spinal cord using a lentiviral vector (LV). Secreted NGF-sNgR promoted neurite outgrowth of dissociated dorsal root ganglion neurons on myelin protein substrate. In a rat dorsal column transection model, regenerating sensory axons were found to grow into the lesion cavity in animals injected with LV/NGF-sNgR, while in animals injected with LV/GFP or LV/NGF-GFP few sensory axons entered the lesion cavity. The results indicate that NGF-sNgR fusion protein can reduce the inhibition of MAIs and facilitate sensory axon regeneration. The fusion constructs may be modified to target other molecules to promote axonal regeneration and the concept may also be adapted to develop gene therapy strategies to treat other disorders.
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVES: Suboptimal bone health is increasingly recognised as an important cause of morbidity. Multiple sclerosis (MS) has been consistently associated with an increased risk of osteoporosis and fracture. Various fracture risk screening tools have been developed, two of which are in routine use and a further one is MS-specific. We set out to compare the results obtained by these in the MS clinic population. DESIGN: This was a service development study. The 10-year risk estimates of any fracture and hip fracture generated by each of the algorithms were compared. SETTING: The MS clinic at the Royal London Hospital. PARTICIPANTS: 88 patients with a confirmed diagnosis of MS. OUTCOME MEASURES: Mean 10-year overall fracture risk and hip fracture risk were calculated using each of the three fracture risk calculators. The number of interventions that would be required as a result of using each of these tools was also compared. RESULTS: Mean 10-year fracture risk was 4.7%, 2.3% and 7.6% using FRAX, QFracture and the MS-specific calculator, respectively (p<0.0001 for difference). The agreement between risk scoring tools was poor at all levels of fracture risk. CONCLUSIONS: The agreement between these three fracture risk scoring tools is poor in the MS population. Further work is required to develop and validate an accurate fracture risk scoring system for use in MS. TRIAL REGISTRATION: This service development study was approved by the Clinical Effectiveness Department at Barts Health NHS Trust (project registration number 156/12).
[Show abstract][Hide abstract] ABSTRACT: Factors modifying the clinical penetrance of DYT1 dystonia are incompletely defined. Particularly, the contribution of extragenetic factors has been subject to only limited investigation and remains largely unexplored. A possible effect of childhood infections has been proposed, and the effect of other factors, such as perinatal adversity and trauma, has not been systematically investigated. We performed an exploratory analysis of the exposure to perinatal adversity, childhood infections, general anaesthesia and trauma comparing 39 manifesting carriers of the ∆GAG mutation, 23 non-manifesting carriers and 48 non-carriers from a multi-centre European series of 28 families with DYT1 dystonia, by means of a self-completed questionnaire and clinical interview. Detailed information on perinatal adversities (pre-term birth, complications at natural delivery, urgent caesarean section), previous childhood infections, and prior general anaesthesia or physical trauma was recorded. A positive association between a history of complications of vaginal delivery and manifestation of dystonia was detected, which was not confounded by age, gender, or education level (odds ratio 8.47, 95 % confidence interval 1.45-49.4, p = 0.02). We could not observe any significant association between presence of dystonia and the other investigated variables. Comparing non-manifesting carriers to non-carriers, the presence of the ∆GAG mutation per se was not associated with any of the environmental exposures explored. Perinatal adversities might modulate the clinical penetrance of DYT1 dystonia; their interaction with known genetic factors modifying penetrance of this condition should be investigated in new, larger collaborative studies.
[Show abstract][Hide abstract] ABSTRACT: A growing number of progressive heredodegenerative conditions mimic the presentation of Huntington's disease (HD). Differentiating among these HD-like syndromes is necessary when a patient with a combination of movement disorders, cognitive decline, behavioural abnormalities and progressive disease course proves negative to the genetic testing for HD causative mutations, that is, IT15 gene trinucleotide-repeat expansion. The differential diagnosis of HD-like syndromes is complex and may lead to unnecessary and costly investigations. We propose here a guide to this differential diagnosis focusing on a limited number of clinical features ('red flags') that can be identified through accurate clinical examination, collection of historical data and a few routine ancillary investigations. These features include the ethnic background of the patient, the involvement of the facio-bucco-lingual and cervical district by the movement disorder, the co-occurrence of cerebellar features and seizures, the presence of peculiar gait patterns and eye movement abnormalities, and an atypical progression of illness. Additional help may derive from the cognitive-behavioural presentation of the patient, as well as by a restricted number of ancillary investigations, mainly MRI and routine blood tests. These red flags should be constantly updated as the phenotypic characterisation and identification of more reliable diagnostic markers for HD-like syndromes progress over the following years.
Journal of neurology, neurosurgery, and psychiatry 09/2012;
The Journal of Physiology 04/2012; 590(Pt 7):1513-4.
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