Interferon-gamma activated calcium influx in peripheral blood lymphocytes from patients with primary and secondary progressive multiple sclerosis.

Interferon-gamma (IFN-gamma) contributes to the early events leading to T cell activation in relapsing-remitting (RR) multiple sclerosis (MS) by activating a transplasmalemma calcium influx, the detection of which is closely associated with clinical and MRI evidence of disease activity. The appearance of this influx represents one of the earliest peripheral events in the pathogenesis of RRMS. It is still questioned whether the same immune mediated mechanisms also operate in primary progressive (PP)MS. Fluorimetric evidence of the IFN-gamma activated calcium influx was sought in 16 patients with PPMS and 39 patients with secondary progressive (SP)MS. To compare peripheral versus CNS evidence of immune activation 11 of the patients with PPMS and 27 of the patients with SPMS underwent gadolinium enhanced brain MRI. The IFN-gamma activated influx was detected in peripheral blood lymphocytes from eight of 16 (50%) patients with PPMS, and 20 of 39 (51%) patients with SPMS, a frequency similar to that previously reported in patients with RRMS during phases of disease stability. Gadolinium enhancing brain MRI lesions were found in only one of 11 (9%) patients with PPMS and 12 of 27 (41%) with SPMS. Our study shows that peripheral blood lymphocytes from patients with PPMS and patients with SPMS express with the same frequency as patients with RRMS, an IFN-gamma dependent intracellular process leading to T cell activation able to trigger disease activity.     

Visual evoked potentials may be recorded simultaneously with fMRI scanning: A validation study

Integrating electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) data may help to optimize anatomical and temporal resolution in the investigation of cortical function. Successful removal of fMRI scanning artifacts from continuous EEG in simultaneous recordings has been reported. We assessed the feasibility of recording reliable visual evoked potentials (VEPs) during fMRI scanning using available artifact removing procedures. EEG during administration of visual stimuli was recorded using MRI-compatible 32-channel equipment in nine normal subjects (mean age, 23.9 +/- 2.5 years), with and without fMRI acquisition. fMRI scanning and cardioballistographic artifacts were removed after subtraction of averaged artifact waveforms. Consistency between VEPs waveforms and of P1 and N1 peak latencies and amplitudes in the two conditions was assessed. Good correlation was found between VEP waveforms (Pearson's correlation coefficient: r(P) between 0.76-0.94 across subjects; P < 0.0001) and between latency or amplitude of P1 and N1 peaks (latencies: r = 0.7, P < 0.035; amplitudes: r > 0.65, P < 0.05; Spearman rank correlation coefficient) in the two recording conditions. No significant differences were found between P1 and N1 parameters in the two conditions (Wilcoxon signed rank test). Consistent VEP waveforms, latencies, and amplitudes with and without fMRI scanning indicate that reliable VEPs may be obtained simultaneously with fMRI recording. This possibility might be helpful by shortening recording times and reducing variability from learning, habituation, and fatigue phenomena from separate recordings for the integration of event-related EEG and fMRI data.     

Immunological patterns identifying disease course and evolution in multiple sclerosis patients

Reliable, and easy to measure, immunological markers able to denote disease characteristics in multiple sclerosis (MS) patients are still lacking. We applied a multivariate statistical analysis on results obtained by measuring-by real-time RT-PCR-mRNA levels of 25 immunological relevant molecules in PBMCs from 198 MS patients. The combined measurement of mRNA levels of IL-1beta, TNF-alpha, TGF-beta, CCL20 and CCR3 was able to distinguish MS patients from healthy individuals. CXCR5, CCL5, and CCR3 combined mRNA levels identify primary progressive MS patients while TNF-alpha, IL-10, CXCL10 and CCR3 differentiate relapsing MS patients. Our results indicate that multi-parametric analysis of mRNA levels of immunological relevant molecules in PBMCs may represent a successful strategy for the identification of putative peripheral markers of disease state and disease activity in MS patients.     

Immature mouse unilateral carotid ligation model of stroke

Cerebral palsy in humans results from a diverse group of disorders that produce nonprogressive motor impairments in the developing brain. Stroke is an important cause of hemiparetic cerebral palsy in neonates and young children. We recently developed a new immature mouse model of stroke that demonstrates seizures, the severity of which correlates with brain injury. This model has strengths compared with other immature rodent models of ischemic injury, such as relative technical ease and the presence of seizures, as is seen in humans. This model also has relative weaknesses, such as the inability to titrate the severity of the injury with different periods of hypoxia. In addition, more work is needed to delineate the long-term consequences of the insult in this new model.     

Cerebrospinal fluid and serum markers of inflammation in autism

Systemic immune abnormalities have no known relevance to brain dysfunction in autism. In order to find evidence for neuroinflammation, we compared levels of sensitive indicators of immune activation: quinolinic acid, neopterin, and biopterin, as well as multiple cytokines and cytokine receptors, in cerebrospinal fluid and serum from children with autism, to control subjects with other neurologic disorders. In cerebrospinal fluid from 12 children with autism, quinolinic acid (P = 0.037) and neopterin (P = 0.003) were decreased, and biopterin (P = 0.040) was elevated, compared with control subjects. In sera from 35 persons with autism, among cytokines, only tumor necrosis factor receptor II was elevated compared with controls (P < 0.02). Decreased quinolinic acid and neopterin in cerebrospinal fluid are paradoxical and suggest dysmaturation of metabolic pathways and absence of concurrent infection, respectively, in autism. Alternatively, they may be produced by microglia but remain localized and not expressed in cerebrospinal fluid.     

Axonal injury and overall tissue loss are not related in primary progressive multiple sclerosis

BACKGROUND: There is an increasing body of evidence that magnetic resonance imaging-occult tissue damage is an important component of primary progressive multiple sclerosis (PPMS) pathology. Proton magnetic resonance spectroscopy (1H-MRS) can be used to measure in vivo whole-brain N-acetylaspartate (WBNAA) concentrations, the decrease of whose levels is considered a marker of neuronal-axonal injury. OBJECTIVES: To study WBNAA 1H-MRS as a tool to provide information about irreversible brain damage in PPMS and to investigate the relationship between WBNAA and other magnetic resonance imaging measures of MS disease burden, including brain atrophy. METHODS: The following magnetic resonance pulse sequences of the brain were obtained from 32 patients with PPMS and 16 age-matched healthy subjects: (1) dual-echo turbo spin-echo; (2) T1-weighted spin-echo; and (3) 1H-MRS to measure WBNAA concentration. Brain total lesion volumes were measured. Normalized brain volumes were calculated using a fully automated technique. Absolute WBNAA amounts were calculated using a phantom replacement method and were then corrected for individual subjects' brain size. RESULTS: Levels of WBNAA concentrations and normalized brain volumes were significantly lower in patients with PPMS (mean values, 10.2 mm and 1500.0 mL, respectively) than in healthy controls (mean values, 12.9 mm and 1585.2 mL). Both WBNAA concentrations and normalized brain volumes were included as independent factors in the final model of a multivariable analysis predicting the subjects' condition. No significant correlations were found between WBNAA values and normalized brain volumes, WBNAA and T2-weighted or T1-weighted lesion volumes. CONCLUSIONS: Axonal-neuronal damage in the brain of patients with PPMS seems to occur, at least partially, independently of the burden of magnetic resonance imaging-visible lesions. Whole-brain N-acetylaspartate values and normalized brain volumes were unrelated in this cohort, thereby suggesting that 1H-MRS and atrophy assessment may provide in vivo complementary information about the actual extent of brain damage in PPMS.     

A case of CPT deficiency, homoplasmic mtDNA mutation and ragged red fibers at muscle biopsy

A 45-year-old male patient had an episode of acute renal failure with myoglobinuria, myalgias, weakness, and markedly increased serum CK levels. Similar episodes had occurred in the past. Carnitine palmitoyl-transferase II (CPT II) deficiency was documented both biochemically and genetically. Interestingly, muscle biopsy also showed some ragged red fibers (RRF) and complete mitochondrial DNA (mtDNA) sequence disclosed a homoplasmic T3394C point mutation. This mutation is described in Leber's hereditary optic neuropathy (LHON) or in patients with diabetes mellitus.     

Developmental and tissue-specific regulation of a novel dysferlin isoform

Dysferlin plays an essential role in the muscle repair machinery, and its deficiency is associated with limb-girdle muscular dystrophy type 2B and with two different distal myopathies (Miyoshi myopathy and distal anterior compartment myopathy). Our aims were to characterize the pattern of dysferlin expression during myogenic cell differentiation and to assess possible differentially spliced isoforms of the DYSF gene. Human primary myogenic cells express a splice variant of dysferlin mRNA lacking exon 17 (Delta17), together with full-length dysferlin mRNA. Real-time polymerase chain reaction analysis of human myoblasts, myotubes, and normal skeletal muscle showed that Delta17 expression inversely correlates with muscle differentiation. Indeed, Delta17 is progressively replaced by the wild type as myoblast fusion proceeds, and it disappears in adult skeletal muscle. Conversely, Delta17 is the predominant dysferlin variant in mature peripheral nerve. Our findings suggest that the two proteins play different roles in myogenic cell differentiation and that dysferlin function in peripheral nerve might be accomplished by this novel isoform.     

The use of magnetic resonance imaging in multiple sclerosis: lessons learned from clinical trials

Magnetic resonance imaging (MRI) is an important paraclinical tool for the diagnosis of multiple sclerosis (MS) and for monitoring its disease course. The efficacy of most of the available MS disease-modifying treatments has been tested in clinical trials where MRI-derived quantities served as primary or secondary outcome measures. However, conventional MRI measures (i.e., the number and volume of contrast-enhancing, the volumes of T2-hyperintense and T1-hypointense lesions and the assessment of brain volume changes) are limited in terms of pathological specificity and, as a consequence, are modestly correlated with clinical measures of disease activity and have a modest prognostic value as predictors of MS evolution. In the present review, we discuss the main factors potentially responsible for the so-called 'clinical MRI paradox' and how modern quantitative MR-based techniques might contribute to, at least partially, overcome it. The lessons learned from MS trials suggest that future applications of MRI to assess MS evolution should rely upon the use of composite measures thought to reflect the various components of the disease, as well as on study protocols specifically designed on the individual trial characteristics.