NS170 Sigma-AldrichPhosphorylated Neurofilament (pNF-H) Sandwich ELISA Kit

Loss of aquaporin 4 and glial fibrillary acidic protein (GFAP) with necrosis and demyelination is a prominent pathologic feature of neuromyelitis optica (NMO). However, the clinicopathologic significance of astrocytic damage and its relation with demyelination are unknown.

Objectives are to examine North Carolina (NC) resident psychiatrists knowledge of commitment statutes and their willingness to involuntarily admit hypothetical patients who do not meet statutory criteria. It is hypothesized that the need for transportation may be a salient factor. In one vignette the patient had schizophrenia and the other alcohol dependence. The respondents were asked to make a decision about commitment and to rate how 9 specified factors affected their decision. Sixty-one residents responded. Thirty percent answered incorrectly about statutory provisions for 'mental illness' and 'dangerousness', 10% answered incorrectly that grave disability does not meet the dangerousness criterion, and 41% answered incorrectly about the NC statutory language of the 'least restrictive alternative' principle. While neither hypothetical patient met the commitment standard, 74% of respondents would involuntarily admit the patient with psychotic illness and 87% would involuntarily admit the patient with alcohol dependence. Training in commitment standards with clinical vignettes should be conducted with residents to protect patient rights.

Guillain-Barré syndrome (GBS) is an acute inflammatory polyneuropathy affecting the myelin-protein sheathing and the axons themselves to various degrees. Damage to these structures causes biomarkers to be released into the adjacent body fluid compartment. In case of the proximal nerve roots these biomarkers diffuse into the cerebrospinal fluid (CSF). Here we review the literature on CSF biomarkers in GBS, including a discussion of CSF basic findings, myelin sheath-associated markers (myelin basic protein), axonal damage markers (neurofilaments, tau, anti-ganglioside antibodies), glial and neuronal markers (neuron specific enolase, 14-3-3 proteins, S100B, hypocretin-1), immunological markers (different chemokines and complement factors, cystatin C, tumor necrosis factor-alpha) as well as recent advances in the field of CSF proteome analysis in GBS. Second, the different pathophysiological mechanisms reflected by these biomarkers are discussed. Finally, candidate biomarkers are reviewed with regard to their clinical relevance to act as a surrogate for the disease process, their value for improving prognostic accuracy and their potential to be used as predictors of treatment response.

The detection of neuron-specific proteins in blood might allow quantification of the degree of neuropathology in experimental and clinical contexts. We have been studying a novel blood biomarker of axonal injury, the heavily phosphorylated axonal form of the high molecular weight neurofilament subunit NF-H (pNF-H). We hypothesized that this protein would be released from damaged and degenerating neurons following experimental traumatic brain injury (TBI) in amounts large enough to allow its detection in blood and that the levels detected would reflect the degree of injury severity. An enzyme-linked immunosorbent assay (ELISA) capture assay capable of detecting nanogram amounts of pNF-H was used to test blood of rats subjected to experimental TBI using a controlled cortical impact (CCI) device. Animals were subjected to a mild (1.0 mm), moderate (1.5 mm), or severe (2.0 mm) cortical contusion, and blood samples were taken at defined times post-injury. The assay detected the presence of pNF-H as early as 6 h post-injury; levels peaked at 24-48 h, and then slowly decreased to baseline over several days post-injury. No signal above baseline was detectable in control animals. Analysis of variance (ANOVA) showed a significant effect of lesion severity, and post hoc analysis revealed that animals given a moderate and severe contusion showed higher levels of blood pNF-H than controls. In addition, the peak levels of pNF-H detected at both 24 and 48 h post-injury correlated with the degree of injury as determined by volumetric analysis of spared cortical tissue. Relative amounts of pNF-H were also determined in different areas of the central nervous system (CNS) and were found to be highest in regions containing large-diameter axons, including spinal cord and brainstem, and lowest in the cerebral cortex and hippocampus. These findings suggest that the measurement of blood levels of pNF-H is a convenient method for assessing neuropathology following TBI.

BACKGROUND: Loss of cortical neurons is a key pathological feature in neurodegenerative dementias. Cerebrospinal fluid (CSF) neurofilaments (Nf) are a biomarker for neuronal death and axonal loss. OBJECTIVE: To perform a meta-analysis to investigate the value of CSF Nf levels for the laboratory-supported differential diagnosis of neurodegenerative dementias. METHODS: A systematic review and meta-analysis of studies on CSF Nf heavy (NfH) and light (NfL) levels in patients with dementia. The dementia subgroups analysed were Alzheimer (AD), frontotemporal lobe dementia (FTLD), vascular dementia (SVD), minimal cognitive deficit (MCI). RESULTS: We identified 12 studies on CSF NfH and NfL levels which met the inclusion criteria and 11 were of a quality good enough to be used in this meta-analysis. CSF data was available on 818 patients (306 AD, 106 SVD, 98 FTLD, 25 MCI, 283 controls). Overall CSF NfH and NfL levels were higher in patients with AD, FTLD and SVD when compared to controls. The size of the effect ranged from 0.71 to 1.38. The strongest effect was observed for the comparison of FTLD patients with controls, both for NfL (1.38) and NfH (0.74). CSF NfL were also able to separate patients with FTLD from those with AD. CONCLUSION: At present we cannot recommend CSF NfH and NfL levels for use as a screening test in the diagnosis of dementia because of the rather small effect size. However, both neurofilament proteins may be of value for targeted investigation of some patients with FTLD, SVD and AD.

Peripherin, a Triton-insoluble protein, whose distribution was found to be restricted to neurons in the rodent and human peripheral nervous system, was characterized by its electrophoretic features (isoelectric point: 5.6; molecular weight: 56,000 daltons) and by its peptidic map after limited proteolysis. Comparative peptide analysis of the 70,000-dalton subunit of neurofilaments (70K NFP), vimentin and peripherin, was performed by two different methods; limited proteolysis with Staphylococcus aureus V8 protease yields a different peptidic map for each protein; treatment with N-chlorosuccinimide, which cleaves preferentially at tryptophan residues, yields only two peptides from each protein: the size of the two fragments indicates that these proteins possess a single tryptophan residue located in the central part of the molecule. A rabbit antiserum raised against mouse peripherin decorated an intracellular filamentous network in mouse neuroblastoma NIE 115 cell line. The IgG fraction of the antiserum recognizes peripherin and the smallest subunit of the neurofilament triplet (70K NFP)--but not vimentin--whereas a monoclonal anti-70K NFP recognizes only the 70K NFP. Moreover, peripherin displays the common antigenic determinant shared by all intermediate filament proteins. Hence, we propose that peripherin represents a new member of the intermediate filament protein family, and might belong to the neurofilament class.