Predicting Clinical Outcomes 7-10 Years after Severe Traumatic Brain Injury: Exploring the Prognostic Utility of the IMPACT Lab Model and Cerebrospinal Fluid UCH-L1 and MAP-2.

BACKGROUND: Severe traumatic brain injury (TBI) is a major contributor to disability and mortality in the industrialized world. Outcomes of severe TBI are profoundly heterogeneous, complicating outcome prognostication. Several prognostic models have been validated for acute prediction of 6-month global outcomes following TBI (e.g., morbidity/mortality). In this preliminary observational prognostic study, we assess the utility of the International Mission on Prognosis and Analysis of Clinical Trials in TBI (IMPACT) Lab model in predicting longer term global and cognitive outcomes (7-10 years post injury) and the extent to which cerebrospinal fluid (CSF) biomarkers enhance outcome prediction. METHODS: Very long-term global outcome was assessed in a total of 59 participants (41 of whom did not survive their injuries) using the Glasgow Outcome Scale-Extended and Disability Rating Scale. More detailed outcome information regarding cognitive functioning in daily life was collected from 18 participants surviving to 7-10 years post injury using the Cognitive Subscale of the Functional Independence Measure. A subset (n = 10) of these participants also completed performance-based cognitive testing (Digit Span Test) by telephone. The IMPACT lab model was applied to determine its prognostic value in relation to very long-term outcomes as well as the additive effects of acute CSF ubiquitin C-terminal hydrolase-L1 (UCH-L1) and microtubule associated protein 2 (MAP-2) concentrations. RESULTS: The IMPACT lab model discriminated favorable versus unfavorable 7- to 10-year outcome with an area under the receiver operating characteristic curve of 0.80. Higher IMPACT lab model risk scores predicted greater extent of very long-term morbidity (ß = 0.488 p = 0.000) as well as reduced cognitive independence (ß = - 0.515, p = 0.034). Acute elevations in UCH-L1 levels were also predictive of lesser independence in cognitive activities in daily life at very long-term follow-up (ß = 0.286, p = 0.048). Addition of two CSF biomarkers significantly improved prediction of very long-term neuropsychological performance among survivors, with the overall model (including IMPACT lab score, UCH-L1, and MAP-2) explaining 89.6% of variance in cognitive performance 7-10 years post injury (p = 0.008). Higher acute UCH-L1 concentrations were predictive of poorer cognitive performance (ß = - 0.496, p = 0.029), whereas higher acute MAP-2 concentrations demonstrated a strong cognitive protective effect (ß = 0.679, p = 0.010). CONCLUSIONS: Although preliminary, results suggest that existing prognostic models, including models with incorporation of CSF markers, may be applied to predict outcome of severe TBI years after injury. Continued research is needed examining early predictors of longer-term outcomes following TBI to identify potential targets for clinical trials that could impact long-ranging functional and cognitive outcomes.

HIV influences microtubule associated protein-2: potential marker of HIV-associated neurocognitive disorders.

OBJECTIVE: Postmortem brains of patients diagnosed with HIV-1-associated neurocognitive disorders (HAND) exhibit loss of dendrites. However, the mechanisms by which synapses are damaged are not fully understood. DESIGN: Dendrite length and remodeling occurs via microtubules, the dynamics of which are regulated by microtubule-binding proteins, including microtubule-associated protein 2 (MAP2). The HIV protein gp120 is neurotoxic and interferes with neuronal microtubules. We measured MAP2 concentrations in human cerebrospinal fluid (CSF) and MAP2 immunoreactivity in rat cortical neurons exposed to HIV and gp120. METHODS: First, we examined whether HIV affects MAP2 levels by analyzing the CSF of 27 persons living with HIV (PLH) whose neurocognitive performance had been characterized. We then used rat cortical neurons to study the mechanisms of HIV-mediated dendritic loss. RESULTS: PLH who had HAND had greater MAP2 concentrations within the CSF than cognitive normal PLH. In cortical neurons, the deleterious effect of HIV on MAP2-positive dendrites occurred through a gp120-mediated mechanism. The neurotoxic effect of HIV was blocked by a CCR5 antagonist and prevented by Helix-A, a peptide that displaces gp120 from binding to microtubules, conjugated to a nanolipoprotein particle delivery platform. CONCLUSION: Our findings support that HIV at least partially effects its neurotoxicity via neuronal cytoskeleton modifications and provide evidence of a new therapeutic compound that could be used to prevent the HIV-associated neuropathology.

Sequential ALK inhibitor treatment benefits patient with leptomeningeal metastasis harboring non-EML4-ALK rearrangements detected from cerebrospinal fluid: A case report.

A 47-year-old female with ALK-rearranged lung adenocarcinoma developed leptomeningeal metastasis (LM) after progression on first-line crizotinib. Alectinib 300 mg was commenced and the patient achieved clinical and radiographic improvements. After nine months of alectinib 300 mg, she started to experience symptomatic LM. Two concurrent non-EML4-ALK rearrangements, LOC388942-ALK and LINC00211-ALK, were identified from the CSF but not from the plasma samples. With the primary lung lesions remaining stable, the alectinib dose was increased to 600 mg twice daily which alleviated the clinical symptoms of symptomatic LM. After 7.6 months of alectinib 600 mg, the patient again experienced CNS progression. With both CSF and plasma samples revealing no druggable mutations, the alectinib dose was re-escalated to 900 mg twice daily, resulting in clinical benefits lasting for two months. Her therapy was then switched to lorlatinib which controlled the disease for 8.7 months until her demise. The LINC00211-ALK fusion, which retains the ALK kinase domain, detected from the CSF was the mechanism of treatment efficacy in this patient. The central nervous system (CNS) has been increasingly recognized as a site of treatment failure in multiple cancers, including non-small cell lung cancer (NSCLC). Our case demonstrated that alectinib dose-escalation and lorlatinib overcame ALK inhibitor resistance in the CNS in an ALK-positive LM patient. Furthermore, we provide the first clinical evidence of the efficacy of sequential ALK inhibitors in targeting LINC00211-ALK in a patient with LM.

Cerebrospinal Fluid Levels of Autophagy-related Proteins Represent Potentially Novel Biomarkers of Early-Stage Parkinson's Disease.

The roles of autophagy-related proteins as diagnostic or monitoring biomarkers in Parkinson's disease (PD) have not been clearly elucidated. We recruited 32 patients with early-stage PD and 28 control subjects, and evaluated parkinsonian motor symptoms and dopamine transporter imaging data. Cerebrospinal fluid (CSF) levels of LC3B, Beclin1, and LAMP-2 were estimated using ELISAs, and CSF levels of ATG5, ATG7, and p62 were examined by immunoblotting. Additionally, we also assessed the levels of α-synuclein, total tau, and phosphorylated tau in CSF using ELISAs. Significant differences in the levels of LC3B, LAMP-2, and Beclin1 were observed between the PD and control groups. Using 29.8 pg/mL as the cut-off value for a diagnostic biomarker of PD, CSF LC3B levels exhibited high sensitivity (96.9%) and specificity (89.3%) with an area under the curve of 0.982. Furthermore, LC3B was significantly correlated with the asymmetry index in the caudate and putamen, as estimated by a semi-quantitative analysis of [18F] N-(3-fluoropropyl)-2ß-carbon ethoxy-3ß-(4-iodophenyl) nortropane (FP-CIT) positron emission tomography (PET). CSF levels of LC3B represented a potential diagnostic and prognostic biomarker of early-stage PD in patients. Based on our findings, molecular biological changes in PD are associated with dysregulation of the lysosomal autophagy pathway.

Temporal Profile of Microtubule-Associated Protein 2: A Novel Indicator of Diffuse Brain Injury Severity and Early Mortality after Brain Trauma.

This study compared cerebrospinal fluid (CSF) levels of microtubule-associated protein 2 (MAP-2) from adult patients with severe traumatic brain injury (TBI) with uninjured controls over 10 days, and examined the relationship between MAP-2 concentrations and acute clinical and radiologic measures of injury severity along with mortality at 2 weeks and over 6 months. This prospective study, conducted at two Level 1 trauma centers, enrolled adults with severe TBI (Glasgow Coma Scale [GCS] score ≤8) requiring a ventriculostomy, as well as controls. Ventricular CSF was sampled from each patient at 6, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216, and 240 h following TBI and analyzed via enzyme-linked immunosorbent assay for MAP-2 (ng/mL). Injury severity was assessed by the GCS score, Marshall Classification on computed tomography (CT), Rotterdam CT score, and mortality. There were 151 patients enrolled-130 TBI and 21 control patients. MAP-2 was detectable within 6 h of injury and was significantly elevated compared with controls (p < 0.001) at each time-point. MAP-2 was highest within 72 h of injury and decreased gradually over 10 days. The area under the receiver operating characteristic curve for deciphering TBI versus controls at the earliest time-point CSF was obtained was 0.96 (95% CI 0.93-0.99) and for the maximal 24-h level was 0.98 (95% CI 0.97-1.00). The area under the curve for initial MAP-2 levels predicting 2-week mortality was 0.80 at 6 h, 0.81 at 12 h, 0.75 at 18 h, 0.75 at 24 h, and 0.80 at 48 h. Those with Diffuse Injury III-IV had much higher initial (p = 0.033) and maximal (p = 0.003) MAP-2 levels than those with Diffuse Injury I-II. There was a graded increase in the overall levels and peaks of MAP-2 as the degree of diffuse injury increased within the first 120 h post-injury. These data suggest that early levels of MAP-2 reflect severity of diffuse brain injury and predict 2-week mortality in TBI patients. These findings have implications for counseling families and improving clinical decision making early after injury and guiding multidisciplinary care. Further studies are needed to validate these findings in a larger sample.

Neonatal hypoxia-ischemia in rat increases doublecortin concentration in the cerebrospinal fluid.

Doublecortin (DCX) is a microtubule-associated protein widely used as an indicator of neurogenesis in immunohistochemical analyses of the postmortem adult brain. A recent study reported that DCX can be quantified in the cerebrospinal fluid (CSF) from healthy rats between postnatal day 0 (P0) and P30. However, it is currently unclear whether the concentration of DCX in the CSF (CSF-DCX) may represent a measure of endogenous neurogenesis. To address this question, this study examined the impact of a neonatal hypoxic-ischemic (HI) brain injury, known to induce neurogenesis, on CSF-DCX. HI was elicited at P7 in Sprague-Dawley rat neonates, and CSF was collected serially from the cisterna magna at P5 and P10, or at P10 and P15. A sandwich immunoassay was used to measure CSF-DCX. Brains from P10 neonates were analyzed immunohistochemically for neurogenesis and cell death markers. Mean CSF-DCX was significantly higher in HI- than in sham-exposed animals, at both P10 and P15. In the HI group at P10, CSF-DCX and stroke severity correlated positively. DCX immunoreactivity was increased in the ipsilateral neurogenic niches from the P10 HI brains in comparison with that of shams. The number of proliferative DCX-positive cells was higher in the ipsilateral hippocampal subgranular zone (SGZ) than in the HI contralateral or sham SGZ. Thus, neonatal HI brain injury disrupts the developmental time-course of DCX levels in the CSF. Our data suggest that the increased concentration of DCX in the CSF after neonatal HI is the result of both cellular injury and increased neurogenesis.

Distinct Lysosomal Network Protein Profiles in Parkinsonian Syndrome Cerebrospinal Fluid.

BACKGROUND: Clinical diagnosis of parkinsonian syndromes like Parkinson's disease (PD), corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) is hampered by overlapping symptomatology and lack of diagnostic biomarkers, and definitive diagnosis is only possible post-mortem. OBJECTIVE: Since impaired protein degradation plays an important role in many neurodegenerative disorders, we hypothesized that profiles of select lysosomal network proteins in cerebrospinal fluid could be differentially expressed in these parkinsonian syndromes. METHODS: Cerebrospinal fluid samples were collected from PD patients (n = 18), clinically diagnosed 4-repeat tauopathy patients; corticobasal syndrome (CBS) (n = 3) and PSP (n = 8); and pathologically diagnosed PSP (n = 8) and CBD patients (n = 7). Each patient set was compared to its appropriate control group consisting of age and gender matched individuals. Select lysosomal network protein levels were detected via Western blotting. Factor analysis was used to test the diagnostic sensitivity, specificity and accuracy of the select lysosomal network protein expression profiles. RESULTS: PD, CBD and PSP were markedly different in their cerebrospinal fluid lysosomal network protein profiles. Lysosomal-associated membrane proteins 1 and 2 were significantly decreased in PD; early endosomal antigen 1 was decreased and lysozyme increased in PSP; and lysosomal-associated membrane proteins 1 and 2, microtubule-associated protein 1 light chain 3 and lysozyme were increased in CBD. A panel of lysosomal-associated membrane protein 2, lysozyme and microtubule-associated protein 1 light chain discriminated between controls, PD and 4-repeat tauopathies. CONCLUSIONS: This study offers proof of concept that select lysosomal network proteins are differentially expressed in cerebrospinal fluid of Parkinson's disease, corticobasal syndrome and progressive supranuclear palsy. Lysosomal network protein analysis could be further developed as a diagnostic fluid biomarker in parkinsonian syndromes.

Biomarkers improve clinical outcome predictors of mortality following non-penetrating severe traumatic brain injury.

OBJECTIVE: This study assessed whether early levels of biomarkers measured in CSF within 24-h of severe TBI would improve the clinical prediction of 6-months mortality. METHODS: This prospective study conducted at two Level 1 Trauma Centers enrolled adults with severe TBI (GCS ≤8) requiring a ventriculostomy as well as control subjects. Ventricular CSF was sampled within 24-h of injury and analyzed for seven candidate biomarkers (UCH-L1, MAP-2, SBDP150, SBDP145, SBDP120, MBP, and S100B). The International Mission on Prognosis and Analysis of Clinical Trials in TBI (IMPACT) scores (Core, Extended, and Lab) were calculated for each patient to determine risk of 6-months mortality. The IMPACT models and biomarkers were assessed alone and in combination. RESULTS: There were 152 patients enrolled, 131 TBI patients and 21 control patients. Thirty six (27 %) patients did not survive to 6 months. Biomarkers were all significantly elevated in TBI versus controls (p < 0.001). Peak levels of UCH-L1, SBDP145, MAP-2, and MBP were significantly higher in non-survivors (p < 0.05). Of the seven biomarkers measured at 12-h post-injury MAP-2 (p = 0.004), UCH-L1 (p = 0.024), and MBP (p = 0.037) had significant unadjusted hazard ratios. Of the seven biomarkers measured at the earliest time within 24-h, MAP-2 (p = 0.002), UCH-L1 (p = 0.016), MBP (p = 0.021), and SBDP145 (0.029) had the most significant elevations. When the IMPACT Extended Model was combined with the biomarkers, MAP-2 contributed most significantly to the survival models with sensitivities of 97-100 %. CONCLUSIONS: These data suggest that early levels of MAP-2 in combination with clinical data provide enhanced prognostic capabilities for mortality at 6 months.

Lysosomal network proteins as potential novel CSF biomarkers for Alzheimer's disease.

The success of future intervention strategies for Alzheimer's disease (AD) will likely rely on the development of treatments starting early in the disease course, before irreversible brain damage occurs. The pre-symptomatic stage of AD occurs at least one decade before the clinical onset, highlighting the need for validated biomarkers that reflect this early period. Reliable biomarkers for AD are also needed in research and clinics for diagnosis, patient stratification, clinical trials, monitoring of disease progression and the development of new treatments. Changes in the lysosomal network, i.e., the endosomal, lysosomal and autophagy systems, are among the first alterations observed in an AD brain. In this study, we performed a targeted search for lysosomal network proteins in human cerebrospinal fluid (CSF). Thirty-four proteins were investigated, and six of them, early endosomal antigen 1 (EEA1), lysosomal-associated membrane proteins 1 and 2 (LAMP-1, LAMP-2), microtubule-associated protein 1 light chain 3 (LC3), Rab3 and Rab7, were significantly increased in the CSF from AD patients compared with neurological controls. These results were confirmed in a validation cohort of CSF samples, and patients with no neurochemical evidence of AD, apart from increased total-tau, were found to have EEA1 levels corresponding to the increased total-tau levels. These findings indicate that increased levels of LAMP-1, LAMP-2, LC3, Rab3 and Rab7 in the CSF might be specific for AD, and increased EEA1 levels may be a sign of general neurodegeneration. These six lysosomal network proteins are potential AD biomarkers and may be used to investigate lysosomal involvement in AD pathogenesis.

[Differential diagnosis of corticobasal syndrome (CBS) and its biomarkers].

Corticobasal degeneration (CBD) was initially thought to represent a clinicopathological entity, but recent studies have shown its considerable clinicopathological heterogeneity. Thus, the constellation of the findings initially considered characteristic of CBD is now named "corticobasal syndrome" (CBS), while the term "CBD" is used for the histopathological disorder. Multiple phenotypes associated with CBD pathology and multiple diseases associated with CBS, the latter of which are called "CBD mimickers," make the correct diagnosis of these conditions on the basis of only clinical symptoms and signs difficult. Therefore, the development of specific biomarkers for diagnosing each causative disease of CBS is extremely important. Abnormal accumulations of the microtubule-associated tau protein are found in both neurons and glia, and CBD is thus considered one of the tauopathies. Although some studies have measured total and phosphorylated tau in the CSF of patients with CBS, their results are inconclusive. Disease-specific truncation and/or phosphorylation of tau protein and its fragments in the CSF would be a promising biomarker candidate; however, its effectiveness still needs to be confirmed by further studies. Progress in biomarker development to differentiate CBD from CBD mimickers has been slow, but it is essential to improve diagnostic accuracy and to develop disease-modifying therapies.

Analysis of adult neurogenesis: evidence for a prominent "non-neurogenic" DCX-protein pool in rodent brain.

Here, we have developed a highly sensitive immunoassay for Dcx to characterize expression in brain and cerebrospinal fluid (CSF) of rodents. We demonstrate that Dcx is widely expressed during development in various brain regions and as well can be detected in cerebrospinal fluid of rats (up to 30 days postnatal). While Dcx protein level decline in adulthood and were detectable in neurogenic regions of the adult rodent brain, similar levels were also detectable in brain regions expected to bear no neurogenesis including the cerebral cortex and CA1/CA3 enriched hippocampus. We monitored DCX protein levels after paradigms to increase or severely decrease adult hippocampal neurogenesis, namely physical activity and cranial radiation, respectively. In both paradigms, Dcx protein- and mRNA-levels clearly reflected changes in neurogenesis in the hippocampus. However, basal Dcx-levels are unaffected in non-neurogenic regions (e.g. CA1/CA3 enriched hippocampus, cortex). These data suggest that there is a substantial "non-neurogenic" pool of Dcx- protein, whose regulation can be uncoupled from adult neurogenesis suggesting caution for the interpretation of such studies.

Expression of liquoral neuroprotection markers in children with acute lymphoblastic leukemia.

Brain damage related to intrathecal methotrexate in children with acute lymphoblastic leukemia (ALL) is still unclear. Neuroinflammatory mechanisms and intracerebral production of specific biomarkers, play a key role in determining neuroprotective mechanisms after brain injury. To determine whether the CSF concentrations of neuron-specific enolase (NSE), neurotrophic factors and doublecortin (DCX) are influenced by repeated intrathecal methotrexate administrations, we prospectively collected CSF samples from 10 children with ALL and 10 controls. Our results showed an increased expression of the liquoral markers. This up-regulation could be interpreted as a neuroprotective response of the brain against the neuronal damages induced by MTX.

NGF, DCX, and NSE upregulation correlates with severity and outcome of head trauma in children.

BACKGROUND: Secondary brain damage after traumatic brain injury (TBI) involves neuroinflammatory mechanisms, mainly dependent on the intracerebral production of specific biomarkers, such as cytokines, neurotrophic factors, and neuron-specific enolase (NSE). NSE is associated with neuronal damage, while neurotrophic factors play a neuroprotective role due to their ability to modulate neuronal precursor biosynthesis, such as doublecortin (DCX). However, the relationships between the expression of these factors and the severity and outcome of TBI are not understood. METHODS: To determine whether the concentrations of neurotrophic factors (nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], glial-derived neurotrophic factor [GDNF]), DCX, and NSE in the CSF of children with TBI correlate with the severity of brain damage and neurologic outcome, we prospectively collected CSF samples from 32 children at 2 and 48 hours after admission for severe TBI and from 32 matched controls. Severity of TBI was evaluated by Glasgow Coma Scale and neurologic outcome by Glasgow Outcome Score. RESULTS: Early NGF, DCX, and NSE concentrations correlated significantly with the severity of head injury, whereas no correlation was found for BDNF and GDNF. Furthermore, NGF and DCX upregulation and lower NSE expression were associated with better neurologic outcomes. No significant association was found between BDNF and GDNF expression and outcome. CONCLUSIONS: Nerve growth factor (NGF), doublecortin (DCX), and neuron-specific enolase concentrations in the CSF are useful markers of brain damage following severe traumatic brain injury (TBI). NGF and DCX upregulation correlates also with better neurologic outcome and could be useful to obtain clinical and prognostic information in children with severe TBI.

Nerve growth factor and doublecortin expression correlates with improved outcome in children with severe traumatic brain injury.

BACKGROUND: In the adult brain, migrating neuroblasts can replace damaged neurons after severe traumatic brain injury (TBI). Little is known about which factors determine the magnitude and amplification of neurogenesis after TBI, but there are some evidences that the nerve growth factor (NGF) and the doublecortin (DCX) can influence neurogenesis and neuronal repair. METHODS: This study investigates the NGF and DCX levels in the cerebrospinal fluid of 12 children with severe TBI and 12 matched controls, to determine the correlation between the expression of both these factors and the patients outcome. We collected cerebrospinal fluid samples 2 hours (Time T1) and 48 hours (Time T2) after brain injury. NGF levels were measured using a two-site immunoenzymatic assay, whereas the DCX expression by a Western blot analysis. RESULTS: At time T1 and T2, children with the best outcomes had higher levels of NGF than children with poor outcomes. Evaluating the change of NGF levels from time T1 to time T2, we found that the NGF up-regulation in the early time after injury was significantly associated with good outcomes of patients. Concomitantly, the expression of DCX increased only in patients with NGF up-regulation from time T1 to time T2. In others patients and in controls the expression of DCX remained unchanged. CONCLUSION: Based on these results, we hypothesize that NGF and DCX contribute to the mechanisms of neuroprotection and neuronal connection reorganization after TBI, playing a key role in the outcome of these patients.

Intraventricular nerve growth factor infusion improves cerebral blood flow and stimulates doublecortin expression in two infants with hypoxic-ischemic brain injury.

OBJECTIVE AND IMPORTANCE: Hypoxic-ischemic brain injuries in childhood are associated with poor neurological outcome. Recently, experimental and clinical works show that nerve growth factor (NGF) reduces neurological deficits and promotes endothelial cells proliferation and angiogenesis following hypoxic-ischemic brain injuries. After brain stroke, new neurons express a protein, called doublecortin (DCX), which indicates a new marker for neurogenesis and migrating neuroblasts. This study investigates the effects of intraventricular NGF administration in two infants with severe hypoxic-ischemic brain damage and its role in both the cerebral perfusion and neurogenesis. CLINICAL PRESENTATION: Two infants, aged 8 and 13 months, with hypoxic-ischemic brain damage, secondary to prolonged cardiorespiratory arrest, were treated with intraventricular NGF administration. Before the therapy, both infants were comatose, aphasic and showed flaccid tetraparesis. After 1 month NGF treatment, their neurological conditions improved, electro-encephalography (EEG) examinations showed increased alpha/theta ratio, and single photon emission computed tomography (SPECT) works demonstrated a better cerebral perfusion. The DCX expression in the cerebrospinal fluid (CSF) increased concomitantly with increasing levels of NGF. INTERVENTION: The drug utilized was 2.5S NGF purified and lyophilized from male mouse submaxillary glands. The NGF administration was started 4 months after ischemic brain injury. NGF (0.1 mg) was administered via the external drainage catheter into the right cerebral ventricle once a day for 10 consecutive days. CONCLUSION: Our study shows that the intraventricular NGF administration improves the cerebral perfusion and stimulates the pathway of neurogenesis differentiation with the activation of DCX biosynthesis.

Increased ALZ-50 immunoreactivity in CSF of pseudotumor cerebri patients.

Pseudotumor cerebri (PTC) is characterized by increased intracranial pressure and papilledema without a mass lesion. PTC predominantly affects obese women. Currently, the pathogenesis of PTC is obscure. Since cytoskeletal abnormalities are found in many neurodegenerative diseases, we hypothesized that some cytoskeletal protein might be involved in the pathophysiology of PTC. Western blotting with specific antibody probes was employed to evaluate ALZ-50 immunoreactive protein, cytoskeletal microtubule-associated protein (MAP), and glial fibrillary acidic protein (GFAP) in cerebrospinal fluid (CSF) samples from 8 PTC patients and 6 controls. Immunoblotting of ALZ-50 in CSF revealed intense staining of 50 kDa protein bands in 7 of 8 PTC patients, while weak staining was found in 4 of 6 controls. Moderate staining of ALZ-50 was seen in 1 of 8 PTC patients and in 2 of 6 controls. CSF blots with anti-ALZ-50 antibody also showed intense staining of a 65 kDa protein band in 3 of the 8 patients but in none of the controls. In anti-MAP CSF blots of the PTC patients and controls, weak staining of the MAP 60 kDa and 50 kDa protein bands was observed. Weak staining of 60 kDa bands was also observed in anti-GFAP CSF blots of all PTC patients and controls. In CSF blots reacted with anti-GFAP antibody, 65 kDa and 32 kDa bands were evident in some PTC patients, but in none of the controls. This study indicates that ALZ-50 immunoreactivity is elevated in CSF of PTC patients. The ALZ-50 immunoreactive protein, either normal tau protein or its phosphorylated variant, may be useful as a biomarker for the diagnosis of PTC. Since the ALZ-50 monoclonal antibody was generated against brain homogenate from Alzheimer's disease (AD) patients, this study suggests a possible link between PTC and AD.

Changes in free amino acid concentrations in serum, brain, and CSF throughout embryogenesis.

Using the developing chick embryo as a model and a very sensitive micromethod for amino acid analysis, a complete analysis is presented of the developmental changes in free amino acid concentration in the blood, in the CSF, and in two different brain regions (optic lobe and frontal lobe) of the chick embryo (from day 4 of incubation, until day 5 post hatching). The developmental profile of Lys is the only one that is almost identical in all three compartments. The developmental profiles of the serum and of the brain are very similar for Arg and Phe, less so for Leu and Gly, and towards the end of the embryonic period, similar also for Val, Ile, Trp, and Met. The amino acid concentrations in the CSF are either much lower than in serum and brain already at the earliest stages, or they progressively decline to levels lower than those in brain and serum, most rapidly between day 6 and 8 of embryonic life. The concentrations of neuroactive amino acids (Gln, Glu, Asp, GABA, Tau, and Gly) in both brain regions begin to increase very early, and continue to rise, except Tau, which goes through a maximum at day 8. Comparative analysis of the developmental profiles of each amino acid in serum, brain, and CSF reveals that the blood supply and the cellular uptake, retention, and metabolism by neural cells are the major determinants of the free amino acid pool of the developing brain.

Two-dimensional electrophoresis of cerebrospinal fluid proteins in normal and pathological conditions.

The two-dimensional polyacrylamide gel electrophoresis technique has been adapted for the analysis of human cerebrospinal fluid proteins. Proteins were detected by Coomassie brilliant blue stain and/or by silver stain. Highly reproducible protein patterns were obtained. We analyzed ten normal CSF specimens, thirty pathological CSF specimens and the corresponding sera. We mapped the protein patterns observed by examination of serum/CSF differences and by immunofixation. Preliminary observations on the changes in protein patterns in CSF specimens from patients with neurological disorders are reported.

The cerebrospinal fluid transferrin/tau proteins. A study by two-dimensional polyacrylamide gel electrophoresis (2D) and agarose isoelectrofocusing (IEF) followed by double-antibody peroxidase labeling and avidin-biotin amplification.

The cerebrospinal fluid (CSF) transferrin/Tau proteins were studied by two-dimensional polyacrylamide gel electrophoresis (2D) followed by immunoblotting and by agarose isoelectrofocusing (IEF), and subsequent double immunofixation, peroxidase staining and Avidin-Biotin Complex (ABC) amplification. The pattern of the Tau protein was similar but not equal to that of the transferrin (Tf). When a genetic variant of Tf was present in the serum, the same variant was also observed in the corresponding CSF Tf and in the Tau fraction. After neuraminidase treatment, both serum and CSF Tf moved to the Tau position on IEF and 2D. On 2D, no desialized precursors of the Tau proteins were detected, whereas the Tf precursors were always detected. No synthesis of the Tau globulin in the brain can, therefore, be inferred. In CSF not treated with neuraminidase, Tf is the only sialoglycoprotein clearly desialized, showing that the Tau fraction cannot be generated by neuraminidase action at CSF level. In fact, the treatment of serum and CSF proteins with neuraminidase produced a clear shift in the isoelectric mobility of all sialoglycoproteins. We clearly demonstrate that the Tau globulin is the result of neuraminidase activity not located in the CSF compartment. We suggest that Tf could be desialized by the action of neuraminidase at the brain level and then be "washed" into the CSF. Brain utilization of Tf, meeting the brain iron requirement, seems likely.