Neuron-specific enolase as a marker of neuronal lesions during various comas in man

Clinical Applications of Extracellular Vesicles in the Diagnosis and Treatment of Traumatic Brain Injury

Extracellular vesicles (EVs) have emerged as key mediators of cell-cell communication during homeostasis and in pathology. Central nervous system (CNS)-derived EVs contain cell type-specific surface markers and intralumenal protein, RNA, DNA, and metabolite cargo that can be used to assess the biochemical and molecular state of neurons and glia during neurological injury and disease. The development of EV isolation strategies coupled with analysis of multi-plexed biomarker and clinical data have the potential to improve our ability to classify and treat traumatic brain injury (TBI) and resulting sequelae. Additionally, their ability to cross the blood-brain barrier (BBB) has implications for both EV-based diagnostic strategies and for potential EV-based therapeutics. In the present review, we discuss encouraging data for EV-based diagnostic, prognostic, and therapeutic strategies in the context of TBI monitoring and management.

Evaluation of Preoperative and Postoperative S100β and NSE Levels in Liver Transplantation and Right Lobe Living-Donor Hepatectomy: A Prospective Cohort Study

BACKGROUND AND AIMS

This study aimed to evaluate plasma neuron-specific enolase (NSE) and S100β levels in orthotopic liver transplantation.

MATERIALS AND METHODS

A total of 56 patients who underwent orthotopic liver transplantation were divided into 3 groups. Healthy donors (group D), end-stage liver failure (ESLF) patients (recipient, group R), and ESLF patients diagnosed with hepatic encephalopathy (HE, group HE). Prognosis, preoperative routine laboratory findings, serum NSE, and S100β in samples obtained preoperation and first and sixth months postoperation were analyzed.

RESULTS

Serum NSE and S100β levels were significantly higher in ESLF patients compared to healthy donors, particularly during the preoperative period. There was a significant decrease in serum NSE and S100β in ESLF patients during the postoperative measurement periods compared to preoperative levels. Serum NSE and S100β levels measured at 3 different time points showed no significant difference between ESLF patients and ESLF patients with HE. However, the recent Model of End-Stage Liver Disease (MELD) and Child-Turcotte-Pugh (CTP) scores showed a significant correlation with serum NSE and S100β in ESLF patients diagnosed with HE. Serum NSE and S100β levels in healthy donors significantly increased within the first month following hepatectomy and decreased in the sixth month following surgery.

CONCLUSION

Although serum NSE and S100β levels significantly decreased with improved liver function in recipients following liver transplantation, there was no complete recovery within 6 months after surgery. The increase in serum levels of NSE and S100β in donors measured following hepatectomy was detected to remain slightly higher in the sixth postoperative months.

Impact of Intraoperative Hyperglycemia on Brain Structures and Volumes

BACKGROUND AND PURPOSE

In hyperglycemic patients, who succumbed to septic shock, an increased rate of apoptosis of microglial cells and damaged neurons of the hippocampus were found. However, the influence of perioperative glucose levels on hippocampal brain structures has not yet been investigated.

METHODS

As part of the ongoing BIOCOG project, a subgroup of N = 65 elderly nondemented patients were analyzed who underwent elective surgery of ≥60 minutes. In these patients, at least one intraoperative blood glucose (BG) measurement was available from the medical charts. Intraoperative glucose maximum was determined in each patient. Preoperatively and at 3 months follow-up, structural neuroimaging was performed with T1-weighted magnetization prepared rapid gradient-echo sequence (MP-Rage) and a dedicated high-resolution hippocampus magnetic resonance imaging (MRI). The MRI scans were analyzed to assess pre- or postoperative volume changes of the hippocampus as a whole and hippocampal subfields. We also assessed changes of frontal lobe volume and cortical thickness.

RESULTS

Overall, 173 intraoperative BG levels were obtained in 65 patients (median 2 per patient). A total of 18 patients showed intraoperative hyperglycemia (glucose maximum ≥150 mg/dL). Controlling for age and diabetes status, no significant impact of intraoperative hyperglycemia was found on the pre-post volume change of the hippocampus as a whole, hippocampal subfields, frontal lobe, and frontal cortical thickness.

CONCLUSIONS

This study found no effect of intraoperative hyperglycemia on postoperative brain structures and volumes including volumes of hippocampus and hippocampal subfields, frontal lobe, and frontal cortical thickness. Further studies investigating the impact of intraoperatively elevated glucose levels should consider a tighter or even continuous glycemic measurement and the determination of central microglial activation.

Loss of Mitochondrial Ndufs4 in Striatal Medium Spiny Neurons Mediates Progressive Motor Impairment in a Mouse Model of Leigh Syndrome

Inability of mitochondria to generate energy leads to severe and often fatal myoencephalopathies. Among these, Leigh syndrome (LS) is one of the most common childhood mitochondrial diseases; it is characterized by hypotonia, failure to thrive, respiratory insufficiency and progressive mental and motor dysfunction, leading to early death. Basal ganglia nuclei, including the striatum, are affected in LS patients. However, neither the identity of the affected cell types in the striatum nor their contribution to the disease has been established. Here, we used a mouse model of LS lacking Ndufs4, a mitochondrial complex I subunit, to confirm that loss of complex I, but not complex II, alters respiration in the striatum. To assess the role of striatal dysfunction in the pathology, we selectively inactivated Ndufs4 in the striatal medium spiny neurons (MSNs), which account for over 95% of striatal neurons. Our results show that lack of Ndufs4 in MSNs causes a non-fatal progressive motor impairment without affecting the cognitive function of mice. Furthermore, no inflammatory responses or neuronal loss were observed up to 6 months of age. Hence, complex I deficiency in MSNs contributes to the motor deficits observed in LS, but not to the neural degeneration, suggesting that other neuronal populations drive the plethora of clinical signs in LS.

Biomarkers

Biomarkers are key tools and can provide crucial information on the complex cascade of events and molecular mechanisms underlying traumatic brain injury (TBI) pathophysiology. Obtaining a profile of distinct classes of biomarkers reflecting core pathologic mechanisms could enable us to identify and characterize the initial injury and the secondary pathologic cascades. Thus, they represent a logical adjunct to improve diagnosis, track progression and activity, guide molecularly targeted therapy, and monitor therapeutic response in TBI. Accordingly, great effort has been put into the identification of novel biomarkers in the past 25 years. However, the role of brain injury markers in clinical practice has been long debated, due to inconsistent regulatory standards and lack of reliable evidence of analytical validity and clinical utility. We present a comprehensive overview of the markers currently available while characterizing their potential role and applications in diagnosis, monitoring, drug discovery, and clinical trials in TBI. In reviewing these concepts, we discuss the recent inclusion of brain damage biomarkers in the diagnostic guidelines and provide perspectives on the validation of such markers for their use in the clinic.

Biomarkers of mild traumatic brain injury in cerebrospinal fluid and blood

Mild traumatic brain injury (TBI), which is defined as a head trauma resulting in a brief loss of consciousness and/or alteration of mental state, is usually benign, but occasionally causes persistent and sometimes progressive symptoms. Whether a threshold for the amount of brain injury and/or individual vulnerability might contribute to the development of these long-term consequences is unknown. Furthermore, reliable diagnostic methods that can establish whether a blow to the head has affected the brain (and in what way) are lacking. In this Review, we discuss potential biomarkers of injury to different structures and cell types in the CNS that can be detected in body fluids. We present arguments in support of the need for further development and validation of such biomarkers, and for their use in assessing patients with head trauma in whom the brain might have been affected. Specifically, we focus on the need for such biomarkers in the management of sports-related concussion, the most common cause of mild TBI in young individuals, to prevent long-term neurological sequelae due to concussive or subconcussive blows to the head.

Regulation of neuron-specific enolase isozyme levels during differentiation of murine neuroblastoma cell cultures

A specific event which accompanies the terminal differentiation of most neurons is the isozymic enolase transition from the ?? form to the ?? and ?? adult neuronal forms. It is partly expressed during maturation of a mouse neuroblastoma clonal cell line (NIE-115). We demonstrate, in these cell cultures, that the significant increase in the concentration of ? gene product, expressed as ?? enolase during differentiation, is due to a parallel and similar increase in its synthesis. The capacities of poly (A)(+) RNA from undifferentiated and differentiated cultures to direct the synthesis of ? gene product were compared in a reticulocyte cell-free protein-synthesizing system. This translating capacity is stimulated in the same proportion as the rate of synthesis of ? antigen in differentiating cell cultures. Therefore the increase in the level of ? protein (expressed mostly as ?? enolase) during differentiation results from the increased translating activity or relative amount of ?mRNA.

Biomarker-based dissection of neurodegenerative diseases

The diagnosis of neurodegenerative diseases within neurology and psychiatry are hampered by the difficulty in getting biopsies and thereby validating the diagnosis by pathological findings. Biomarkers for other types of disease have been readily adopted into the clinical practice where for instance troponins are standard tests when myocardial infarction is suspected. However, the use of biomarkers for neurodegeneration has not been fully incorporated into the clinical routine. With the development of cerebrospinal fluid (CSF) biomarkers that reflect pathological events within the central nervous system (CNS), important clinical diagnostic tools are becoming available. This review summarizes the most promising biomarker candidates that may be used to monitor different types of neurodegeneration and protein inclusions, as well as different types of metabolic changes, in living patients in relation to the clinical phenotype and disease progression over time. Our aim is to provide the reader with an updated lexicon on currently available biomarker candidates, how far they have come in development and how well they reflect pathogenic processes in different neurodegenerative diseases. Biomarkers for specific pathogenetic processes would also be valuable tools both to study disease pathogenesis directly in patients and to identify and monitor the effect of novel treatment strategies.

Auditory neuropathy in hyperbilirubinemia: is there a correlation between serum bilirubin, neuron-specific enolase levels and auditory neuropathy?

This study evaluated whether a correlation exists between increased serum bilirubin and neuron-specific enolase (NSE) assays (a biochemical index of neuronal damage) and auditory neuropathy. Nineteen term neonates without hemolysis whose serum bilirubin levels were above 20 mg/dl and 27 healthy term newborns with bilirubin levels <13 mg/dl were included in the study. Auditory brainstem responses (ABRs) and transient evoked otoacoustic emissions (TEOAEs) of patients with hyperbilirubinemia were obtained before discharge. This preliminary study did not show any correlation between the serum NSE and bilirubin values. However, infants who had auditory neuropathy had significantly higher NSE levels, and thus these patients, being in the high-risk group, need close follow-up.

Cerebrospinal fluid levels of markers of brain parenchymal damage in Vietnamese adults with severe malaria

A retrospective study of cerebrospinal fluid (CSF) markers of brain parenchymal damage was conducted in Vietnamese adults with severe malaria. Three markers were analysed by immunoassays: the microtubule-associated protein tau, for degenerated axons; neuron-specific enolase (NSE), for neurons; and S100B for astrocytes. The mean concentration of tau proteins in the CSF was significantly raised in patients with severe malaria compared with controls (P=0.0003) as reported for other central nervous system diseases. By contrast, the mean concentration of NSE and S100B remained within the normal range. Tau levels were associated with duration of coma (P=0.004) and S100B was associated with convulsions (P=0.006). Concentrations of axonal and astrocyte degeneration markers also were associated with vital organ dysfunction. No association was found between the level of markers of brain parenchymal damage on admission and a fatal outcome. On admission to hospital, patients with severe malaria had biochemical evidence of brain parenchymal damage predominantly affecting axons.

Concentration of neuron-specific enolase and S100 protein in the subretinal fluid of rhegmatogenous retinal detachment

BACKGROUND

Neuron-specific enolase and S100 protein are markers of neuronal lysis. To assess the neuronal suffering in rhegmatogenous retinal detachment we quantified neuron-specific enolase and S100 protein in the subretinal fluid.

METHODS

The puncture was performed in the sclera with a Merseture 5/0 round needle, and the fluid was collected with a glass capillary tube. Twelve subretinal fluid samples were obtained from 12 eyes with rhegmatogenous retinal detachment undergoing retinal detachment surgery. Vitreous from ten eyes with macular hole or epimacular membrane served as negative control group, and vitreous collected during cornea procurement from ten deceased patients served as positive control group.

RESULTS

The mean concentration of neuron-specific enolase (in nanogrammes per millilitre) was 602 in the subretinal fluid of rhegmatogenous retinal detachment, 10.2 in the serum of these patients, 2.9 in the vitreous of the negative control group, and 364 in the positive control group. The mean concentration of S100 protein (in nanogrammes per millilitre) was 104 in the subretinal fluid of rhegmatogenous retinal detachment, <0.1 in the serum of these patients and in the vitreous of the control negative group, and 11.18 in the positive control group.

CONCLUSION

Neuron-specific enolase (NSE) and S100 are known to be good markers of brain stress and, thus, are good markers of retinal stress.

S-100b and neuron-specific enolase in patients with fulminant hepatic failure

Patients with fulminant hepatic failure (FHF) frequently develop cerebral edema and intracranial hypertension. The aim of this study was to evaluate circulating S-100b and neuron-specific enolase (NSE) levels as markers of neurological outcome in patients with FHF. In a subgroup of patients, the cerebral flux of S-100b and NSE was measured. We included 35 patients with FHF, 6 patients with acute on chronic liver disease (AOCLD), 13 patients with cirrhosis of the liver without hepatic encephalopathy, and 8 healthy subjects. Blood samples were obtained from catheters placed in the radial artery and internal jugular bulb. The net cerebral flux of S-100b and NSE was measured, and the effect of short-term hyperventilation, as well as the effect of high-volume plasmapheresis, on circulating levels of these two biomarkers was determined. Blood levels of S-100b were greater in patients with FHF and AOCLD than patients with cirrhosis and healthy subjects (median, 0.39 microg/L; range, 0.02 to 10.31 microg/L; and 1.11 microg/L; range, 0.19 to 4.84 microg/L v 0.05 microg/L; range, 0.02 to 0.27 microg/L; and 0.09 microg/L; range, 0.02 to 0.15 microg/L, respectively; P <.05, ANOVA). Among patients with FHF, blood levels of NSE tended to be greater in patients who subsequently developed cerebral herniation than in survivors (median, 10.5 microg/L; range, 5.2 to 15.9 microg/L v 5.1 microg/L; range, 2.8 to 12 microg/L; P =.05). There was no net cerebral flux of S-100b or NSE. Short-term hyperventilation had no effect on any of these measures, whereas high-volume plasmapheresis reduced circulating S-100b levels from 0.45 microg/L (range, 0.19 to 10.31 microg/L) to 0.42 microg/L (range, 0.11 to 6.35 microg/L; P =.01). In conclusion, blood levels of S-100b were elevated in almost all patients with FHF and AOCLD, but were unrelated to survival. Conversely, NSE showed a clear tendency toward greater circulating levels in patients with FHF who subsequently developed cerebral herniation than in survivors. This finding encourages further evaluation of NSE as a marker of neurological outcome in FHF.

Concentrations of nucleotides, nucleosides, purine bases, oxypurines, uric acid, and neuron-specific enolase in the cerebrospinal fluid of children with sepsis

To determine the effects of sepsis on cerebral energy metabolism, the cerebrospinal fluid adenosine monophosphate, inosine monophosphate, inosine, adenosine, guanosine, hypoxanthine, xanthine, and urate concentrations were determined by high-performance liquid chromatography and the neuron-specific enolase levels by means of an enzyme immunoassay method in 32 children with sepsis, without meningitis, aged between 2 months and 13 years, and in 160 age-matched controls. The septic group had significantly higher cerebrospinal fluid concentrations of inosine, adenosine, xanthine, and urate than controls. These results suggest that sepsis could provoke some degree of neuronal hypoxia and significant alterations of cerebral energy metabolism homeostasis.

Serum neuron-specific enolase as a predictor of intracranial lesions in children with head trauma: a pilot study

OBJECTIVE

To determine the reliability of serum neuron-specific enolase (NSE) levels in predicting intracranial lesions (ICL) in children with blunt head trauma (HT).

METHODS

A prospective pilot study was conducted of patients 0 to 18 years of age presenting to a children's hospital emergency department (ED) between December 1997 and October 1998. Children presenting within 24 hours of injury who required head computed tomography (CT) were eligible. Blood samples were obtained to measure serum NSE level. Data collected included patient demographics, historical information, Glasgow Coma Scale score (GCS), physical examination, head CT results, and outcome. Patients were assigned to one of two groups based on the head CT results (PICL; presence of intracranial lesion, or NICL; no intracranial lesion). Data were analyzed using Student's t-test and chi-square. The 95% confidence interval (95% CI) was calculated when appropriate. A receiver operating characteristic curve was constructed to determine the NSE level that yielded the highest sensitivity and specificity for predicting ICL.

RESULTS

Fifty patients were enrolled; 22 (45%) had abnormal head CT. No difference in demographics or mechanism of injury was observed between those with abnormal or normal CT scans. The mean GCS level was 11.9 +/- 4.2 for PICL and 13.9 +/- 2.6 for NICL (p = 0.045; 95% CI = -0.05 to -3.9). The mean NSE level was 26.7 +/- 21.4 for PICL and 17.7 +/- 7.8 for NICL (p = 0.048; 95% CI = 0.1 to 17.9). An NSE level > or = 15.3 ng/mL yielded a sensitivity of 77%, a specificity of 52%, and a negative predictive value of 74%.

CONCLUSIONS

These results suggest that serum NSE may be a useful screening tool for predicting ICL in children with blunt head trauma. However, the NSE alone was neither sensitive nor specific in predicting all patients with ICL.

Quantitative immunochemistry on neuronal loss, reactive gliosis and BBB damage in cortex/striatum and hippocampus/amygdala after systemic kainic acid administration

Cell specific markers were quantified in the hippocampus, the amygdala/pyriform cortex, the frontal cerebral cortex and the striatum of the rat brain after systemic administration of kainic acid. Neuron specific enolase (NSE) reflects loss of neurons, glial fibrillary acidic protein (GFAP) reflects reactive gliosis, and brain levels of serum proteins measures blood-brain-barrier permeability. While the concentration of NSE remained unaffected in the frontal cerebral cortex and the striatum, their GFAP content increased during the first three days. In the hippocampus and amygdala, NSE levels decreased significantly. GFAP levels in the hippocampus were unaffected after one day and decreased in the amygdala/pyriform cortex. After that, GFAP increased strikingly until day 9 or, in the case of amygdala/pyriform cortex, even longer. This biphasic time course for GFAP was accompanied by a decrease of S-100 during days 1-9 followed by a significant increase at day 27 above the initial level. The regional differences in GFAP and S-100 could result from the degree of neuronal degeneration, the astrocytic receptor set-up and/or effects on the blood-brain barrier.

Subtle brain damage cannot be detected by measuring neuron-specific enolase and S-100beta protein after carotid endarterectomy

OBJECTIVE

To assess whether subtle brain damage after carotid endarterectomy could be detected using serum levels of neuron-specific enolase (NSE) or S-100beta protein.

DESIGN

Prospective noninterventional study.

SETTING

University hospital.

PARTICIPANTS

Twenty-two patients undergoing carotid endarterectomy and 16 patients undergoing repair of abdominal aortic aneurysm.

INTERVENTIONS

Serum levels of NSE and S-100beta protein were measured in all patients before surgery and postoperatively at 12, 24, 36, and 48 hours. In patients undergoing carotid endarterectomy, neuropsychologic testing was performed before surgery and postoperatively at discharge from the hospital and after 3 months using a neuropsychologic test battery.

MEASUREMENTS AND MAIN RESULTS

Compared with abdominal aortic surgery patients, the preoperative serum concentration of NSE was significantly higher in carotid artery surgery patients. Postoperatively, the NSE serum level decreased significantly after uncomplicated carotid artery surgery, and the level was then similar to that in the aortic surgery patients. Before operation, the S-100beta protein levels were similar in the two groups, but a significant increase was seen in aortic surgery patients postoperatively. Neuropsychologic testing after uncomplicated carotid artery surgery revealed cognitive dysfunction in 2 of 20 (10%) of the patients after 5 days and 3 of 16 (19%) of the patients after 3 months. There was no correlation between the change in cognitive function and the changes in blood levels of either NSE or S-100 protein.

CONCLUSIONS

Subtle brain damage after carotid artery surgery could not be detected by measuring blood levels of NSE and S-100beta protein. The NSE level was significantly higher before carotid artery surgery and decreased postoperatively to the level observed in aortic surgery.

Quantification of axonal damage in traumatic brain injury: affinity purification and characterization of cerebrospinal fluid tau proteins

Diffuse axonal injury is a primary feature of head trauma and is one of the most frequent causes of mortality and morbidity. Diffuse axonal injury is microscopic in nature and difficult or impossible to detect with imaging techniques. The objective of the present study was to determine whether axonal injury in head trauma patients could be quantified by measuring levels of CSF tau proteins. Tau proteins are structural microtubule binding proteins primarily localized in the axonal compartment of neurons. Monoclonal antibodies recognizing the form of tau found in the CSF of head trauma patients were developed by differential CSF hybridoma screening using CSF from head trauma and control patients. Clones positive for head trauma CSF tau proteins were used to characterize this form of tau and for ELISA development. Using the developed ELISA, CSF tau levels were elevated >1,000-fold in head trauma patients (mean, 1,519 ng/ml of CSF) when compared with patients with multiple sclerosis (mean, 0.014 ng/ml of CSF; p < 0.001), normal pressure hydrocephalus (nondetectable CSF tau), neurologic controls (mean, 0.031 ng/ml of CSF; p < 0.001), or nonneurologic controls (nondetectable CSF tau; p < 0.001). In head trauma, a relationship between clinical improvement and decreased CSF tau levels was observed. These data suggest that CSF tau levels may prove a clinically useful assay for quantifying the axonal injury associated with head trauma and monitoring efficacy of neuroprotective agents. Affinity purification of CSF tau from head trauma patients indicated a uniform cleavage of approximately 18 kDa from all six tau isoforms, reducing their apparent molecular sizes to 30-50 kDa. These cleaved forms of CSF tau consisted of the interior portion of the tau sequence, including the microtubule binding domain, as judged by cyanogen bromide digestion. Consistent with these data, CSF cleaved tau bound taxol-polymerized microtubules, indicating a functionally intact microtubule binding domain. Furthermore, epitope mapping studies suggested that CSF cleaved tau proteins consist of the interior portion of the tau sequence with cleavage at both N and C terminals.

Neuron-specific enolase levels in the cerebrospinal fluid of neurologically healthy children

Levels of neuron-specific enolase (NSE) levels in the cerebrospinal fluid (CSF) of children without neurological disease were assessed. CSF samples were obtained from 37 subjects aged between 1 month and 13 years. All subjects had undergone lumbar puncture for diagnostic purposes, and were subsequently shown not to be suffering any form of neurological disease. NSE levels in CSF were determined by an enzyme immunoassay method. NSE level ranged from below the detection limit to 4.8 ng/ml (1.52+/-1.01 ng/ml). The present results may be useful as a basis for defining reference levels of NSE in CSF in post-neonatal children.

Serum and CSF levels of neuron-specific enolase (NSE) in cardiac surgery with cardiopulmonary bypass: a marker of brain injury?

We investigated whether neuron-specific enolase (NSE) in serum or cerebrospinal fluid (CSF) reflects subtle or manifest brain injury in children undergoing cardiac surgery using cardiopulmonary bypass (CPB). NSE was measured in serum (s-NSE) before, and up to, 102 h after surgery in 27 children undergoing cardiac surgery with CPB. In 11 children, CSF-NSE was also measured 48 or 66 h post-surgery. As erythrocytes contain NSE, hemoglobin concentration in the samples was determined spectrophotometrically at 550 nm (cut-off limit: absorbance 0.4 = 560 mg/l) in 14 children and in a further 13 children by spectroscopic multicomponent analysis (cut-off limit 5 micromol/l = 80 mg/l). One hundred and one of 214 post-operative serum samples (47%) had to be discarded because of hemolysis (18% spectrophotometrically at 550 nm and 88% with spectroscopic multicomponent analysis). On the first and second post-operative day, the median s-NSE values were significantly higher when compared with samples taken after 54 h or longer (P = 0.008 and P = 0.002). All CSF-NSE levels were within the normal range and below the s-NSE measured in the same patient. Although in our study elevated s-NSE seems to indicate brain injury in CPB-surgery, the low concentration of NSE in the post-operative CSF of 11 children puts the neuronal origin of s-NSE in question. NSE from other non-neuronal tissues probably contributes to the elevated s-NSE. Additionally, normal post-operative CSF-NSE values in two children with post-operative neurological sequelae might question the predictive value of CSF-NSE with regard to brain injury.

Serum neuron-specific enolase as a prognostic marker for irreversible brain damage in comatose cardiac arrest survivors

OBJECTIVE

To assess the use of serum neuron-specific enolase (S-NSE) level as a noninvasive predictor of CNS injury irreversibility in comatose cardiac arrest survivors.

METHODS

An observational, prospective clinical study was performed in a community hospital ED and intensive care unit. All cardiac arrest survivors (n = 52) with impaired neurologic status admitted between February 1994 and May 1995 were followed until return of consciousness (1) or death due to CNS failure (0). Serum samples for S-NSE determination (ng/mL) using the radioimmunoassay technique were obtained 24 hours after cardiac arrest. Data were analyzed using stepwise logistic regression with dichotomized predictors to validate the correlation between S-NSE (X) and outcome (Y), where X = 0 if < or = median and 1 if > median S-NSE level. Adjustment was made for the following variables: glucose level on admission, total epinephrine dose used before return of spontaneous circulation, and best Glasgow Coma Scale score on admission. These data were all available in 34 cases. In 16 cases, CSF enzymes at 48 hours postarrest were obtained and compared with S-NSE.

RESULTS

The logistic equation determining the influence of S-NSE (X) on outcome (Y) was: Y = 0.606-1.785X (odds ratio = 6; p = 0.020). There was no confounding effect of the other variables related to survival. The mean S-NSE value for all the patients was 34 (7.9-188). All the patients recovering consciousness (n = 15) had an S-NSE mean +/- SEM value of 17.5 +/- 2.4, with a maximum of 47.

CONCLUSION

These data support the conclusion that measurement of S-NSE at 24 hours post-cardiac arrest may supplement clinical assessment of hypoxic-ischemic encephalopathy after cardiac arrest.

Increased serum levels of neuron-specific enolase in epileptic patients and after electroconvulsive therapy--a preliminary report

Serum neuron-specific enolase (NSE) levels were studied by an enzymo-immunoassay method in 2 groups of patients: a group of epileptic patients, and a group of patients with refractory major depression after electroconvulsive therapy (ECT). In patients without organic neurological disease (n = 274) the mean serum NSE level (+/- S.D.) was 8.4 +/- 3.4 micrograms/l. No correlation with sex or age was observed. No significant difference was observed between epileptic patients without seizure or major electroencephalogram (EEG) abnormality, and a reference group. Significant increases were observed in 32 samples collected from patients with interictal EEG without spikes and waves before the 7th day after a seizure, in whom mean NSE was 21.5 +/- 9.4 micrograms/l, and in 26 samples from 4 patients without seizures but with spikes and waves in the interictal EEG, whose mean NSE was 20.6 +/- 11.5 micrograms/l. The increases of serum NSE levels in epileptic patients seem therefore to be linked to seizures and/or to EEG abnormalities. The consequences of these observations for the survey of epileptic patients, and for the diagnosis of cerebral tumors (mainly neuroblastoma) or for monitoring treatment after surgical resection, are discussed. In only 1 patient out of 6, an increase in serum NSE levels was observed with a peak about 12 h after ECT. No significant correlation with the ECT features (length of seizures, one- or two-sided electrodes) was observed.

The significance of neuron specific enolase levels in cerebrospinal fluid and serum after experimental traumatic brain damage

In the posttraumatic period, measurement of neural tissue enzymes in serum and cerebrospinal fluid gives quantitative information about the severity of the head injury. In our study, we evaluated the relationship between the serum and cerebrospinal fluid levels of neuron specific enolase and the severity of trauma. Head traumas at different severity were applied experimentally (Mild 0.038 N, Moderate 0.057 N, Severe 0.3 N). Serum and cerebrospinal fluid levels of neuron specific enolase were measured in trauma and control groups of rats. Only in the severe trauma group, the neuron specific enolase levels of cerebrospinal fluid were significantly increased. There was no statistically significant difference between the groups when serum neuron specific enolase levels were evaluated. Our data leads us to conclude that trauma, causing significant neural damage, results in an increase in cerebrospinal fluid neuron specific enolase levels, however the serum neuron specific enolase levels do not seem to run parallel with that increase.

Diagnostic significance of serum neuron-specific enolase and myelin basic protein assay in patients with acute head injury

BACKGROUND

Neuron-specific enolase (NSE) and myelin basic protein (MBP) in the peripheral venous blood (PVB) have been reported to be sensitive markers for judging the prognosis of patients with head injury. However, to our knowledge, the levels of NSE and MBP in the internal jugular venous blood (IJVB) have never been studied.

METHODS

In 25 patients with acute head injury, blood samples were taken from the internal jugular vein and the peripheral vein at the same time before any medical or surgical procedure was performed. The levels of NSE and MBP in the both venous blood samples were measured. The time interval between injury and sampling was 1.5-8.0 hours (mean 4.3 hours). The levels of NSE and MBP in the IJVB were compared to those in the PVB. The relationship between the clinical outcome and the serum levels of those was evaluated.

RESULTS

The levels of NSE and MBP in the IJVB were almost equal to those in the PVB. The levels of NSE and MBP were significantly higher in the patients who died than in those who survived. In the survivors, the levels of NSE and MBP in the IJVB were 17.6 +/- 11.4 ng/ml and 1.4 +/- 1.5 ng/ml, whereas in the patients who died, both levels were elevated to 51.3 +/- 27.3 ng/ml (p < 0.005) and to 11.3 +/- 9.5 ng/ml (p < 0.01), respectively.

CONCLUSIONS

The assay of serum NSE and MBP levels provides a reliable laboratory indicator of the degree of brain damage and allows early prediction of the prognosis in patients with acute head injury.

Neuron specific enolase in asphyxiated newborns: association with encephalopathy and cerebral function monitor trace

Neuron specific enolase (NSE) in serum and cerebrospinal fluid (CSF) and glutamate in CSF were investigated in the immediate postasphyctic period in 22 term newborn infants. The cerebral function monitor (CFM) pattern was also assessed and hypoxic-ischaemic encephalopathy (HIE) was graded. NSE was significantly increased in the CSF of infants with HIE (median value 25.4 micrograms/l) compared with control infants (10.0 micrograms/l). Infants with the highest concentrations died. NSE in CSF correlated with the degree of asphyxial damage. Glutamate and NSE in CSF did not correlate, presumably due to the different time factors of the release after the insult. NSE in CSF corresponded well with the type of CFM pattern, which was also highly predictive of outcome.

Neurotrophic and neuroprotective effects of neuron-specific enolase on cultured neurons from embryonic rat brain

We previously reported that the gamma gamma-isozyme of enolase, NSE), one of the glycolytic enzymes, promoted the survival of embryonic rat neocortical neurons in culture, but alpha alpha-isozyme (non-neuronal enolase) had no effect. In the present study, the neurotrophic effects of NSE on cultured mesencephalic and spinal neurons from rat embryo were examined. NSE promoted the survival of neurons not only in neocortical cultures but also in mesencephalic and spinal cord cultures. Furthermore, NSE showed neuroprotective action on cultured neocortical neurons in a low-oxygen atmosphere. By contrast, non-neuronal enolase did not show any neurotrophic or neuroprotective activities. To clarify the mechanism of the neurotrophic effect of NSE, the binding of NSE to cultured neurons was determined by radio-receptor assay using 125I-labelled NSE. The specific binding, which was dose-dependent, saturable, and calcium-dependent, could be detected. These results suggest that NSE has neurotrophic and neuroprotective effects on rather a broad spectrum of neurons in the central nervous system. The existence of specific binding of NSE to cultured neurons suggests the possibility that receptor-like or carrier-like molecules on the neuronal surface are involved in the neurotrophic activity of NSE.

Serum neurone-specific enolase concentrations in patients with neurological disorders

A radioimmunoassay (RIA) has been developed for neurone-specific enolase (NSE) and used to measure serum levels in patients with a range of neurological disorders. Serum NSE levels were within the normal range in 21 patients with multiple sclerosis and 4 patients with Guillain-Barre syndrome. Normal serum NSE levels were also recorded in patients with motor neurone disease, anterior spinal thrombosis, multi-infarct disease, benign intracranial hypertension and peripheral neuropathy. However, two patients in coma, one as a result of encephalitis, the other due to subarachnoid haemorrhage (SAH) had elevated serum NSE. In the former, serum NSE levels appeared to predict a deterioration in clinical state, levels later returning to normal before an improvement in clinical condition. In the patient with SAH, levels were elevated on admission and remained elevated until death. Serum NSE levels may be of use in predicting outcome in patients with acute neurological disease.

The fluctuations of neuron-specific enolase (NSE) levels of cerebrospinal fluid during bacterial meningitis: the relationship between the fluctuations of NSE levels and neurological complications or outcome

Neuron-specific enolase (NSE) is one of the glycolytic enzymes distributed exclusively in neurons. It was measured serially in the cerebrospinal fluid (CSF) of 10 children with bacterial meningitis during the illness using radio-immunoassay. The relationship between CSF-NSE levels and neurological complications or outcome was examined. CSF-NSE levels were significantly higher in the patients with bacterial meningitis than in the patients with the other central nervous system (CNS) infectious diseases, suggesting that CNS damage in those patients with bacterial meningitis was exacerbated. As CSF-NSE levels increased to above 25 ng/mL in the acute phase, all patients except one had subdural effusion. In those patients whose CSF-NSE level rose again during the illness, CNS complications or sequelae occurred. CSF-NSE may be a useful prognostic factor for predicting CNS damage in childhood bacterial meningitis.

Neuron-specific enolase concentrations in blood as a prognostic parameter in cerebrovascular diseases

BACKGROUND AND PURPOSE

To investigate the clinical relevance of plasma concentrations of neuron-specific enolase (NSE) in patients with severe cerebrovascular diseases, serial analyses were performed during the first 10 days after the acute event.

METHODS

Plasma samples taken from 61 patients (30 with brain infarction, 13 with intracerebral hemorrhage, 11 with cardiogenic hypoxia-ischemia, and 7 with myocardial infarction [as control group]) were analyzed for NSE concentration using an enzyme immunoassay. The time course of plasma NSE was correlated with clinical findings, clinical outcome, cranial computed tomography, intracranial pressure, and other laboratory data.

RESULTS

In cases of hypoxia-ischemia there was close correlation between plasma NSE values during the first 72 hours and the clinical outcome. In brain infarction and intracerebral hemorrhage, high plasma NSE mostly indicated an unfavorable outcome, but low values did not permit a reliable prognostic estimation. In cases of cerebral infarction and intracerebral hemorrhage with secondary neuronal destruction (for example, due to malignant edema), increasing NSE concentrations in plasma preceded the change of clinical or other diagnostic parameters.

CONCLUSIONS

The course of plasma NSE levels is seen as a relevant parameter for assessing the prognosis of cerebral hypoxia-ischemia. Additionally, it may prove to be a useful tool for monitoring space-occupying brain infarctions and intracerebral hemorrhages and therefore may contribute to improved therapeutic management of severe cerebrovascular diseases.

Neuron-specific enolase increases in cerebral and systemic circulation following focal ischemia

Neuron-specific enolase (NSE) is an isoform of the glycolytic enzyme, enolase, and is found in neurons and neuroendocrine cells. We evaluated cerebral immunohistologic and plasma changes in NSE in rats from 2 h to 15 days following permanent or transient middle cerebral artery occlusion (MCAO). At 1-2 days post-MCAO, loss of NSE immunofluorescence from within neurons to the extracellular space was observed in the infarcted areas of all MCAO animals. NSE also was identified intravascularly throughout the brain following MCAO. NSE in plasma was determined by a specific radioimmunoassay. Plasma NSE following permanent or transient MCAO was increased significantly from that observed in controls (2.8 +/- 0.3 ng/ml) beginning at 2 h and persisting for 2.5 days post-MCAO (maximum levels of 8.8 +/- 0.9 to 9.6 +/- 0.5 ng/ml after 6-12 h; P < 0.05, n = 4-9). Quantified contralateral forelimb and hindlimb neurological deficits in these animals were significant and persisted for at least 15 days following MCAO but were not observed following sham surgery. These data suggest that MCAO-induced cortical infarction and neurological dysfunction is associated with neuronal depletion and vascular redistribution of brain NSE resulting in a measurable increase in plasma NSE. Such diffusion of NSE into the cerebral vasculature and systemic circulation from ischemic tissue can be expected to serve as a marker for the incidence of cerebral damage in acute and chronic ischemic brain infarcts.

Cerebrospinal fluid 28-kDa calbindin-D as a possible marker for Purkinje cell damage

To examine the clinical value of 28-kDa calbindin-D (CaBP) in cerebrospinal fluid (CSF) as a marker for the damage to Purkinje cells, we measured CSF CaBP levels using an enzyme immunoassay method in 107 patients with cerebellar and other neurological diseases, and 26 controls. The mean CaBP level was markedly elevated in patients with cerebellar diseases, and the elevation of CaBP level was more frequent in the diseases involving Purkinje cells, such as multiple system atrophy (MSA) and subacute cerebellar degeneration in association with lung cancer. Further, in MSA patients, the CaBP levels decreased with duration of illness. The mean levels of CaBP were also elevated in some of the other diseases. We conclude that the elevations of CaBP levels are not specific for cerebellar diseases, but CSF CaBP may be a useful marker for examining the Purkinje cell involvement in cerebellar diseases.

CSF and serum brain-specific creatine kinase isoenzyme (CK-BB), neuron-specific enolase (NSE) and neural cell adhesion molecule (NCAM) as prognostic markers for hypoxic brain injury after cardiac arrest in man

Creatine kinase (CK) and its brain-specific isoenzyme (CK-BB), neuron-specific enolase (NSE), neural cell adhesion molecule (NCAM) and the ions sodium, potassium, chloride and calcium were measured both in CSF and serum and inorganic phosphate in CSF in order to assess their prognostic value in total brain ischemia due to cardiac arrest. The samples were collected at 4, 28 and 76 h after resuscitation. Twenty consecutive patients resuscitated from ventricular fibrillation or asystole were included in the study. Nine of the patients recovered consciousness (recovered) but eleven remained comatose (disabled). The follow-up period was 2 years after which only one patient was still alive. The earliest statistically significant differences between neurologically recovered and disabled patient groups were seen in CSF inorganic phosphate (P = 0.030) already at 4 h and CK-BB (P = 0.046) and NSE (P = 0.020) activity at 28 h. Later, at 76 h after the resuscitation CSF NSE differentiated the groups most clearly (P = 0.014). The values were higher in the disabled patients. A negative correlation between CSF parameters and Glasgow Coma scores was also seen at these timepoints. Statistically significant differences between the groups were seen in both CSF and blood pCO2, pO2, base excess (BE) and actual bicarbonate (HCO3-). CSF or serum NCAM has no prognostic value in anoxic-ischemic coma. The results suggest that in CSF CK-BB and NSE are useful prognostic indicators of hypoxic brain injury when measured 28-76 h after cardiac arrest whereas blood samples have no prognostic value.

In vivo activation of kainate receptors induces dephosphorylation of the heavy neurofilament subunit

Injection of kainic acid (KA) into the rat hippocampus reduced the phosphorylation-related immunoreactivity of the heavy subunit of neurofilament proteins (NF-H). The effect was demonstrated quantitatively with a dot-immunobinding assay and qualitatively by immunoblotting with monoclonal antibodies against phosphorylation-dependent and nonphosphorylation-related epitopes of NF-H. The KA-induced reduction affected 50% of the phosphorylated NF-H in half of the hippocampus after 48 h. At the same time, the nonphosphorylation-related NF-H immunoreactivity increased as revealed by immunoblotting, indicating a shift from phosphorylated to nonphosphorylated NF-H. The effects on NF-H preceded a decrease in content of the neuron-specific enolase, a soluble neuronal cytoplasmic protein. No alterations of the light subunit of neurofilament proteins occurred, suggesting that KA has a preferential effect on NF-H phosphorylation. N-Methyl-D-aspartate administered similarly did not lead to a rapid dephosphorylation of NF-H. We propose that kainate receptor-mediated dephosphorylation in NF-H is involved in the signal transduction of excitatory amino acids with consequences for neuronal functions dependent on intermediary filament phosphorylation.

Measurement of gamma-enolase release, a new method for selective quantification of neurotoxicity independently from glial lysis

We have developed a sensitive enzymatic-immunoassay to quantify the level of gamma-enolase (a specific neuronal enzyme) which is released from cultured cells after exposure to various toxins. We show that this method can estimate selectively neuronal cell death without significantly interfering with glial cell death. Indeed, no gamma-enolase is released when glial cells are killed with free-radical producing agents. Experiments comparing the levels of neuronal cell death induced by NMDA or free-radical producing drugs, performed either by measuring gamma-enolase release or using the classical fluorescein diacetate method, yielded similar results. In addition to selectively follow neuronal death in a mixed population of neurons and glial cells, this method provides a way of determining the cell death kinetics from a single culture dish, since enolase can be measured on small samples taken from the culture medium. Finally, we propose these two methods as being complementary and useful neuronal and other cellular death indexes and also to understand the complex problem of glial influence on neuronal survival or death.

CSF neuron-specific enolase as a quantitative marker of neuronal damage in a rat stroke model

A technique for chronic cisternal cerebrospinal fluid (CSF) sampling in conscious rats was used to obtain multiple 50 microliters samples before and up to 7 days after middle cerebral artery occlusion. Neuron-specific enolase (NSE) concentrations were measured by radioimmunoassay using a readily available kit. The volume of infarction was measured by integrating the area of damage on 9 evenly spaced histological sections of the forebrain. This correlated well (r = 0.97, P less than 0.001) with the concentration of CSF neuron-specific enolase integrated over the first 5 days post occlusion, in animals with pure cortical and mixed cortical and striatal lesions. The correlation was maintained in animals given the NMDA antagonist MK-801. There was also a good correlation between the CSF NSE concentration 3 days post-MCAO and the volume of infarction (r = 0.92, P less than 0.01). It is therefore possible that CSF neuron-specific enolase may be useful as a quantitative marker of ischaemic damage in humans and provide a useful adjunct in the assessment of neuroprotective drugs in stroke.

The pathogenesis of cerebral gliomatous cysts

In this study, the authors have examined the mechanism of the formation of tumor cysts. Cyst fluid samples were obtained during surgery and by percutaneous aspiration from 22 patients with cystic cerebral gliomas. The concentration of protein was measured in the cyst fluid and blood plasma. Analysis of brain tumor cyst fluids revealed that plasma proteins constituted a major fraction (92%) of cyst fluid proteins; moreover, the protein fractions occurred in concentrations (relative to the plasma concentrations) that were around 50-fold of those in cerebrospinal fluid. This strongly indicates blood-brain barrier disruption. Evidence from computed tomographic and magnetic resonance imaging scans as well as from electron microscopy of tumor cyst walls suggests the transition of spongy edematous tissue in or around tumors into the contents of associated cysts. Pathophysiologically, blood-brain barrier breakdown is inherent to the occurrence of vasogenic brain edema. It is therefore plausible that the development of cysts is related to peritumoral vasogenic edema.

Serum neurone specific enolase (NSE) levels as an indicator of neuronal damage in patients with cerebral infarction

A radioimmunoassay has been developed and used to measure serum neurone specific enolase (NSE) concentrations in 24 patients, following cerebral infarction. A significant correlation between cerebral infarct volume and maximum serum NSE concentration was observed (P = 0.047). Serum NSE was also assayed at times 24, 48, 72 and 96 h post ictus. At 72 h a significant correlation existed between serum NSE levels and infarct volume (P = 0.012), and levels appeared to be approaching statistical significance at 48 h (P = 0.067). No correlation existed at 24 and 96 h. In addition serum concentrations of NSE were compared to clinical outcome as determined by the Glasgow Outcome Score. Using the Mann-Whitney U test, there was no significant difference in maximum NSE level between patients graded 1-3 on the Glasgow Outcome Score and those graded 4 and 5. However, further studies are required on a larger population to more completely assess this. NSE may prove to be a useful marker of neuronal damage in the study of stroke, with particular application in the assessment of treatment.

Serum neuron-specific enolase levels after subarachnoid hemorrhage

We examined serum levels of neuron-specific enolase by enzyme immunoassay in 29 patients with subarachnoid hemorrhage due to ruptured cerebral aneurysm. Serum neuron-specific enolase levels were significantly higher in patients with a poor neurological status than in patients with a good neurological status on admission, and the greater the amount of subarachnoid blood, the higher the serum neuron-specific enolase level. Patients with a good outcome had low serum neuron-specific enolase levels throughout their courses. Serum neuron-specific enolase levels increased with development of delayed ischemic neurological deficits and, especially in poor outcome patients, high levels persisted until 3 weeks after the subarachnoid hemorrhage.

Changes of neuron-specific enolase concentration in plasma after cardiac arrest and resuscitation

The concentration of neuron-specific enolase (NSE) was measured in plasma of 18 patients after cardiac arrest and resuscitation (14 nonsurvivors and 4 survivors). In all patients, the NSE concentration was significantly higher in comparison to reference values. The highest concentration was measured in nonsurvivors. Time-course investigation in the first 24 h after cardiac arrest was performed in five patients. Two nonsurvivors and one survivor of the five patients showed a significant rise, and a NSE peak concentration of 42.7 micrograms/L, 13.6 micrograms/L, and 10.5 micrograms/L, respectively, was found 10-19 h after cardiac arrest.

Cerebrospinal fluid markers in neurological disorders

Cerebrospinal fluid (CSF) markers are a useful tool for determining disease progression or activity in some neurological disorders which need parameters both for evaluating treatments and investigating pathobiological evolution in research-oriented follow-up. A number of CSF proteins are reviewed with data on biological properties, analytical methods, clinical usefulness of: myelin basic protein, S-100 protein, glial fibrillary acidic protein, neural-cell adhesion molecule, neuron-specific enolase and others.

Development of a radioimmunoassay for neurone specific enolase (NSE) and its application in the study of patients receiving intra hepatic arterial streptozotocin and floxuridine

A radioimmunoassay has been developed for neurone specific enolase (NSE) and used to measure serum NSE levels in patients with neuroendocrine and non-neuroendocrine tumours following intra hepatic arterial chemotherapy. Ten patients were studied, 7 receiving streptozotocin and floxuridine for neuroendocrine tumours and three receiving cisplatinum for non-neuroendocrine neoplasms. All ten patients had liver metastases. In patients with tumours of neuroendocrine origin, a significant increase in serum NSE was recorded within 24 h of therapy. Slight increases in serum NSE levels were also recorded in three patients with non neuroendocrine tumours. These increases may reflect lysis of neuroendocrine cells within the tumour. Raised levels in non-neuroendocrine tumour patients may reveal damage done to healthy neuronal and neuroendocrine cells during treatment. NSE may be a useful marker of the extent of cell death following chemotherapy.

Detection of neuron specific enolase concentrations in cerebrospinal fluid from patients with neurological disorders by means of a sensitive enzyme immunoassay

An enzyme linked immunosorbent assay (ELISA) for the detection of neuron specific enolase (NSE) in cerebrospinal fluid (CSF) was developed. The sensitivity of the ELISA was less than 1 microgram/ml. This sensitivity is comparable with radioimmunoassays which have the disadvantage that radiolabelled products are used. The developed assay was used to measure cerebrospinal fluid neuron specific enolase (CSF-NSE) levels in 1178 patients with neurological disorders to establish its potential usefulness and clinical application. CSF-NSE levels in this group of patients were independent of sex and no correlation with age was found. CSF-NSE was significantly increased in Creutzfeldt-Jacob disease, meningeal hemorrhage, thrombosis, Guillain-Barré syndrome and in schizophrenia.

Clinical biochemistry of neuron specific enolase

The soluble brain protein 14-3-2 first described by Moore and McGregor in 1965 is now known to be a cell specific isoenzyme of the glycolytic enzyme enolase (EC 4.2.1.11), designated neuron specific enolase (NSE). It is not only a marker for all types of neurons, but also for all neuroendocrine or paraneuronal cells. The appearance of NSE is a late event in neural differentiation, thus making NSE a useful index of neural maturation. The demonstration that tumors of the nervous system and of neuroendocrine origin contain NSE has promoted the study of NSE as a possible tumor marker. Immunocytochemistry has been used to identify NSE in cytologic preparations from several types of tumors, offering useful indications for differential diagnosis. NSE levels in serum from tumor patients are not useful in the diagnosis of early stage disease. However, serum NSE levels have been shown to be helpful in the identification of advanced small cell lung cancer, neuroblastoma and several other neoplasms. The main use of serum NSE is the monitoring of chemotherapy and the detection of a relapse in these cases.

Elevated levels of the alpha subunit of GTP-binding protein Go in cerebrospinal fluid of patients with neurological disorders

By employing a highly sensitive immunoassay method, concentration of the alpha subunit of GTP-binding protein, Go (Go alpha), recently shown to be localized mainly in nervous tissues and neuroendocrine cells, was determined in cerebrospinal fluids (CSF) of 192 patients with various neurological disorders and 50 control subjects. The results were compared with CSF levels of neuron-specific enolase (NSE) and S-100b protein (S-100b) in the same samples. Normal levels of Go alpha were 51.9 +/- 21.7 pg/ml. The levels of Go alpha, as well as NSE and S-100b, in CSF were enhanced in some patients with acute conditions, e.g., meningitis (48%), encephalitis (100%), and cerebral infarct (56%). In these disorders, cases with enhanced Go alpha levels were more frequent than those with enhanced NSE or S-100b. Three patients with encephalitis whose Go alpha levels were more than 1000 pg/ml all died; the remaining two patients with encephalitis and slightly elevated Go alpha levels had a good prognosis. Concentration of Go alpha in CSF correlated well with that of NSE but poorly with that of S-100b. However, cervical spondylosis and demyelinating diseases, CSF levels of Go alpha were generally lower than those of NSE or S-100b. These results suggest that Go alpha in CSF is a useful marker for monitoring patients with acute neuronal damage. Since these three proteins are distributed differently in the central nervous system, simultaneous determination of Go alpha, NSE, and S-100b levels in CSF might provide valuable information about the pathophysiology of neurological disorders.

An immunobioluminescence assay for gamma-gamma enolase activity in human serum and cerebrospinal fluid

A solid phase immunobioluminescence assay for the measurement of gamma-gamma enolase activity in human serum and cerebrospinal fluid is described. The assay combines the specificity of the antiserum with the specificity of measuring enolase activity, thus making the assay highly specific for gamma-gamma enolase. The sensitivity of the method allows determinations in unconcentrated cerebrospinal fluid samples. The new immunobioluminescence assay has been compared with a radioimmunoassay method. The correlation is good both for serum and CSF samples. However, different correlation lines are found for serum and CSF.

Blood cell superoxide dismutase and enolase activities as markers of alcoholic and nonalcoholic liver diseases

Monitoring of chronic alcoholism would be facilitated by using sensitive biochemical markers in blood cells, mainly to detect differences between alcoholic subjects with or without liver injury. We propose two types of markers: the first one is superoxide dismutase (SOD) activity involved in the conversion of superoxide radicals (O2-.) formed during acetaldehyde oxidation by xanthine oxidase after chronic alcohol consumption; the second one is enolase activity with both isoenzyme forms: nonneuronal enolase (NNE) and neuron specific enolase (NSE) which has been shown to be modified in many injuries related to the glycolytic pathways. For SOD activity we found a significant increase in alcoholic patients with liver injury and mainly in cirrhotic patients with ascitis. Both enolase activities were also found to be significantly increased in alcoholic patients with liver injury but NNE activity was also increased in alcoholics without apparent liver disease. Our results suggest that increased activity of SOD and NSE in blood cells may be related to liver injury mainly in alcoholism while increased NNE activity may also be a marker of alcohol abuse without liver injury.

Cerebrospinal fluid neuron-specific enolase is decreased in multi-infarct dementia, but unchanged in Alzheimer's disease

Cerebrospinal fluid (CSF) levels of neuron-specific enolase (NSE) were measured in 22 patients with probable Alzheimer's disease and in 35 patients with multi-infarct dementia, and in 15 controls. CSF NSE in patients with Alzheimer's disease did not differ from those in controls. In patients with multi-infarct dementia without recent vascular events CSF NSE was lower than in controls or in Alzheimer patients. This finding is in accord with the prevailing opinion that vascular dementia is caused by multiple infarcts and not by continuous neuronal ischaemia.