Glial fibrillary acidic protein and neurofilament in children with cerebral white matter abnormalities

Glial fibrillary acidic protein (GFAP) is the major structural protein of the intermediate filaments found in glial cells. Increased levels in the cerebrospinal fluid (CSF) have been found to indicate gliosis. Neurofilament (NFL) is a structural element of neurons, mainly found in large myelinated axons. Its presence in the CSF has been suggested to reflect destruction of axons. The aim of this study was to see if GFAP and NFL in the CSF of children with neurological disabilities and an abnormal signal on magnetic resonance imaging (MRI) of the cerebral white matter could be used to clarify the underlying neuropathology. The potential of GFAP and NFL to differentiate a progressive disease from a stationary disorder was investigated, as was the correlation with disability and clinical findings. CSF from 26 children, eleven with progressive and 15 with non-progressive disorders, was analysed. GFAP was increased in all, interpreted to reflect gliosis. NFL was elevated in seven and considered to indicate ongoing neuroaxonal damage as all but one patient were found to have a progressive disease. GFAP did not differentiate between progressive and non-progressive disorders, although low levels were found in stationary and high levels in progressive disorders. The severity of the disability correlated with the NFL levels, but not with the concentration of GFAP.

Biological data and clinical symptoms as predictors of astrogliosis and neurodegeneration in patients with second-stage Trypanosoma brucei gambiense sleeping sickness

Concentrations of glial fibrillary acidic protein (GFAp) and light subunit neurofilament protein (NFL) in cerebrospinal fluid (CSF) were measured in patients with second-stage Trypanosoma brucei gambiense sleeping sickness. Correlations between GFAp and NFL in CSF as markers for astrogliosis and neurodegeneration, and clinical and biological data were investigated. Abnormal levels of GFAp and NFL were significantly associated with increasing CSF cell number and protein concentration, and with the absence of lymph nodes or the absence of trypanosomes in lymph node aspirate. A significant association was found between abnormal NFL and presence of trypanosomes in CSF, abnormal limb movements, difficulties in gait and coordination, and low Karnofsky index. By multivariate analysis, it was shown that increasing CSF cell number, increasing CSF protein concentration, and the absence of lymph nodes or the absence of trypanosomes in the lymph node aspirate were the best predictors for astrogliosis and neurodegeneration among the variables tested. These results demonstrate the importance of CSF cell count and protein determination in assessment of the severity of central nervous system involvement and reinforces the importance of laboratory diagnosis to assess the stage of the disease. The clinical symptoms studied were less useful in predicting astrogliosis or neurodegeneration.

Neurofilament protein in cerebrospinal fluid: a marker of white matter changes

The objective of this study was to compare cerebrospinal fluid (CSF) levels of the light subtype of the neurofilament proteins (NFL), tau, and beta-amyloid42 (Abeta42) in individuals with moderate or severe white matter changes (WMC) and in those with mild or no WMC. Twenty-two patients with Alzheimer's disease (AD), nine patients with subcortical vascular dementia (SVD), and 20 normal controls were included in the study. The occurrence of WMC was evaluated by a neuroradiologist using the Blennow-Wallin scale. Thirty-seven subjects had no or only punctate WMC; 14 had moderate to severe WMC. Both diagnostic group and WMC, but not gender or apolipoproteinE E4 inheritance, contributed to the variance in the CSF levels of tau, NFL, and Abeta42. In patients with moderate to severe WMC, CSF NFL (P < 0.01), but not CSF tau or CSF Abeta42, was increased also after correction for age, gender, and degree of cognitive impairment. A comparison between patients and controls with any signs of WMC and those without such signs yielded a similar result: CSF NFL (P < 0.001) was increased in the group with signs of WMC. As in numerous previous studies, we found that CSF tau was increased in AD (P < 0.001) compared with controls. Furthermore, CSF NFL was increased in both AD and SVD compared with controls (P < 0.001 for both). Although diagnostic group seems to be a stronger predictor of the variance found in CSF NFL, a clear association between the presence of WMC and increased CSF NFL was found. Because NFL is located mainly in large myelinated axons, increased CSF NFL in individuals with WMC probably reflects axonal degeneration.

Normal levels of clusterin in cerebrospinal fluid in Alzheimer's disease, and no change after acute ischemic stroke

The protein clusterin has been suggested to be involved in the pathogenesis of Alzheimer's disease (AD). Its expression is increased in brain regions affected by AD pathology, and to elucidate if there is a concomitant increase of clusterin also in the cerebrospinal fluid (CSF) in different neurological disorders, CSF samples from patients with AD, vascular dementia (VAD), Parkinson's disease (PD), and controls were analysed. Also longitudinal (five occasions) samples from patients with acute stroke were analysed, to follow any degenerative/regenerative phase after acute brain damage. However, there were no changes in CSF-clusterin levels from patients in AD, VAD, PD or acute stroke, as compared to controls. The increase of clusterin in brain tissue is suggested to reflect a regenerative response process, which here is shown not to be followed by a concomitant increase in the CSF. Thus, CSF-clusterin can not be used as an indicator or a diagnostic marker for AD.

Brain-specific proteins in the cerebrospinal fluid of severely asphyxiated newborn infants

Upcoming trials of neuroprotective strategies in severely asphyxiated newborn infants emphasize the need for early and objective markers of both good and bad long-term prognosis. Traditional markers such as neurological depression and seizures are not specific.

AIM

To study whether measurement in the cerebrospinal fluid of some proteins known to be specific to the central nervous system was in covariance with the clinical course and long-term prognosis.

METHODS

Twenty-two asphyxiated infants were included in the study and compared with a control group of 8 infants without signs of perinatal asphyxia. Cerebrospinal fluid (CSF) was collected during the first 4 d of life and analysed for neurofilament protein (NFp), glial fibrillary acidic protein (GFAp), protein S-100 and neuron-specific enolase (NSE).

RESULTS

The concentrations of all four proteins were significantly increased in the CSF of asphyxiated infants. The concentrations correlated significantly with other indicators of long-term prognosis and to neurological impairment at I y of age, or death before that time. Specifically, concentrations were excessively high in the five infants who died.

CONCLUSIONS

High concentrations of brain-specific proteins are released into the CSF of asphyxiated infants. It might therefore be useful to measure these concentrations when excluding patients with the gravest prognosis from neuroprotective trials.

CSF-neurofilament and levodopa tests combined with discriminant analysis may contribute to the differential diagnosis of Parkinsonian syndromes

The differentiation between Parkinson's disease (PD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) is important for prognostic and therapeutic purposes. In order to evaluate the diagnostic capability of two tests reflecting these items, patients fulfilling strict clinical criteria for PD (n=35), MSA (n=36) and PSP (n=14), were consecutively included. An analysis of neurofilament protein (NFL), a marker of axonal degeneration in the cerebrospinal fluid (CSF) and a levodopa test, recorded with optoelectronic technique were performed. Using discriminant analyses, the test's abilities to predict the clinical PD or non-PD (MSA and PSP) diagnoses were compared. Whereas the CSF-NFL and levodopa tests predicted 79 and 85% correct diagnoses respectively, the combined test predicted 90% correct diagnoses. We conclude that the CSF-NFL and levodopa tests provide detailed information of clinical variables on which the clinical diagnostic criteria are based. As they are pathologically unrelated, the diagnostic precision increases compared to clinical diagnoses when they are combined.

Serum levels of the brain-derived proteins S-100 and NSE predict long-term outcome after cardiac arrest

BACKGROUND AND PURPOSE

patients with cardiac arrest have a high mortality and the long-term outcome is doubtful. The prognosis is mainly dependent on clinical parameters. S-100 and neurone specific enolase (NSE) are established biochemical markers of central nervous system (CNS) injury. The purpose of this study was to validate the use of serum determinations of S-100 and NSE with neurological investigations in regard to brain damage and long-term outcome after cardiac arrest.

METHODS

neurological examinations were performed on 66 patients after cardiac arrest. Serum levels of S-100 and NSE were determined during the first 3 days of post arrest, using commercial luminescent immunoassays (LIAs). The main outcome variable was the Glasgow Outcome Scale (GOS), while secondary variables were the activity of daily living (ADL) index and mini mental state examination (MMSE). Outcome was determined at 1 year.

RESULTS

the serum levels of S-100 and NSE were increased during the first 3 days after the arrest and were related to coma depth, time of anoxia and abnormal brain stem reflexes. High levels predicted a poor outcome, according to the GOS (death, vegetative state and severe disability). The prognostic value of the brain damage markers was comparable with that of traditional clinical parameters. None of the secondary outcome variables (ADL and MMSE) was strongly associated with S-100 or NSE.

DISCUSSION

the serum levels of S-100 and NSE increased after cardiac arrest due to the anoxic brain damage. The determination of S-100 and NSE can be used as an adjunct to predict long-term outcome after cardiac arrest.

Brain specific proteins in posthaemorrhagic ventricular dilatation

Median neurofilament and glial fibrillary acidic protein concentrations in the cerebrospinal fluid of 18 infants with posthaemorrhagic ventricular dilatation were 20-200 times higher than control values. S-100 protein in cerebrospinal fluid was four times higher than control values. Glial fibrillary acidic protein concentrations correlated with death or disability and with parenchymal lesions but not with shunt dependence.

Antisense inhibition of BCL-2 expression induces retinoic acid-mediated cell death during differentiation of human NT2N neurons

Changes in expression of the proto-oncogene Bcl-2 are well known in the developing brain, with a high expression level in young post-mitotic neurons that are beginning the outgrowth of processes. The physiological significance of the Bcl-2 up-regulation in these neurons is not fully understood. We used a differentiation model for human CNS neurons to study the expression and function of Bcl-2. NT2/D1 human neuronal precursor cells differentiated into a neuronal phenotype in the presence of 10 microM retinoic acid for 3-5 weeks. This concentration of retinoic acid was not toxic to undifferentiated NT2/D1 cells but was sufficient to up-regulate the BCL-2 protein in 6 days. The BCL-2 levels increased further after 3 weeks, i.e. when the cells started to show neuronal morphology. Inhibition of the accumulation of endogenous BCL-2 with vectors expressing the antisense mRNA of Bcl-2 caused extensive apoptosis after 3 weeks of the retinoic acid treatment. The loss of neuron-like cells from differentiating cultures indicated that the dead cells were those committed to neuronal differentiation. Death was related to the presence of retinoic acid since withdrawal of retinoic acid after 16 days of treatment dramatically increased cell surviving. The ability of BCL-2 to prevent retinoic acid-induced cell death was also confirmed in undifferentiated NT2/D1 cells that were transfected with a vector containing Bcl-2 cDNA in sense orientation and exposed to toxic doses (40-80 microM) of retinoic acid. Furthermore, down-regulation of BCL-2 levels by an antisense oligonucleotide in neuronally differentiated NT2/D1 cells increased their susceptibility to retinoic acid-induced apoptosis. These results indicate that one function of the up-regulation of endogenous BCL-2 during neuronal differentiation is to regulate the sensitivity of young post-mitotic neurons to retinoic acid-mediated apoptosis.

Transient increase in total tau but not phospho-tau in human cerebrospinal fluid after acute stroke

An increase in cerebrospinal fluid (CSF)-total-tau, and recently also in CSF-phospho-tau, has been found in Alzheimer's disease (AD). However, the mechanisms for these changes are not known. We examined longitudinal CSF samples from nine patients with acute stroke. As compared with baseline levels (day 0-1), CSF-total-tau showed an increase at day 2-3 (179%; P=0.018), day 7-9 (257%; P=0.003), and after 3 weeks (425%; P=0.002) and returned to normal levels after 3-5 months (140%; NS). In contrast, there was no significant change in CSF-phospho-tau. These findings suggest that total tau and phospho-tau in CSF reflect different pathogenic processes in the brain; total-tau the degree of neuronal damage and phospho-tau the phosphorylation state of tau and thus possibly the formation of neurofibrillary tangles.

Cerebrospinal fluid markers for Alzheimer's disease evaluated after acute ischemic stroke

Potential cerebrospinal fluid (CSF) markers for Alzheimer's disease (AD) include tau protein, the 42 amino-acid form of amyloid beta (amyloid beta(1-42)) and apolipoprotein E (apoE). To study new aspects of these protein markers, we examined consecutive CSF samples from 26 patients with acute ischemic stroke. CSF samples were taken on day 0-1, day 2-3, day 7-9, 3 weeks and 3-5 months after the stroke. CSF-tau showed a marked increase day 2-3, which peaked after 1 week and returned to normal after 3-5 months. CSF-tau also showed correlation (r=0.95; p<0.01) with the size of the infarct. In contrast, CSF-amyloid beta(1-42) and CSF-apoE showed no significant changes during the period. The marked increase in CSF-tau levels after acute ischemic stroke indicate that CSF-tau reflect the degree of neuronal damage. The reason for unchanged levels of CSF-amyloid beta(1-42) and CSF-apoE after ischemic stroke remains unclear.

No evident neuronal damage after electroconvulsive therapy

Electroconvulsive therapy (ECT) is regarded as one of the most effective treatments for major depressive disorder but has also been associated with cognitive deficits possibly reflecting brain damage. The aim of this study was therefore to evaluate whether ECT induces cerebral damage as reflected by different biochemical measures. The concentrations in the cerebrospinal fluid (CSF) of three established markers of neuronal/glial degeneration, tau protein (tau), neurofilament (NFL) and S-100 beta protein, were determined in nine patients who fulfilled DSM-IV criteria for major depression. CSF samples were collected before and after a course of six ECT sessions. The CSF/serum (S) albumin ratio reflecting potential blood-brain barrier (BBB) dysfunction was also determined at these time points. The treatment was clinically successful with a significant decline of depressive symptoms in all patients as assessed by the Montgomery-Asberg Rating Scale for Depression. Several patients had signs of BBB dysfunction and/or neuronal damage before the start of treatment. Levels of CSF-tau, CSF-NFL and CSF-S-100 beta levels were not significantly changed by ECT. Also the CSF/S albumin ratio was found to be unchanged after the course of ECT. In conclusion, no biochemical evidence of neuronal/glial damage or BBB dysfunction could be demonstrated following a therapeutic course of ECT.

Growth hormone increases connexin-43 expression in the cerebral cortex and hypothalamus

Several studies indicate that systemic GH influences various brain functions. Connexin-43 forms gap junctions that mediate intercellular communication and establish the astroglial syncytium. We investigated the effects of peripheral administration of bovine GH (bGH) and recombinant human insulin-like growth factor I (rhIGF-I) on the expression of connexin-43 in the rat brain. Hypophysectomized female Sprague Dawley rats were substituted with cortisol (400 microg/kg x day) and L-T4 (10 microg/kg x day) and treated with either bGH (1 mg/kg x day) or rhIGF-I (0.85 mg/kg x day) for 19 days. The abundance of connexin-43 messenger RNA (mRNA) and protein in the brainstem, cerebral cortex, hippocampus, and hypothalamus was quantified by means of ribonuclease protection assays and Western blots. Treatment with bGH increased the amounts of connexin-43 mRNA and protein in the cerebral cortex and hypothalamus. No changes were found in the brainstem or hippocampus. Infusion of rhIGF-I did not affect connexin-43 mRNA or protein levels in any of the brain regions studied. These results show that administration of bGH increases the abundance of cx43 in specific brain regions, suggesting that GH may influence gap junction formation and thereby intercellular communication in the brain.

Difference in pathogenesis between herpes simplex virus type 1 encephalitis and tick-borne encephalitis demonstrated by means of cerebrospinal fluid markers of glial and neuronal destruction

We determined the extent of neuronal and glial cell destruction in 13 patients with herpes simplex type 1 (HSV-1) encephalitis, 15 patients with tick-borne encephalitis (TBE), and 20 noninfectious controls by analyzing the cerebrospinal fluid (CSF) concentrations of neurofilament protein (a marker of neurons, mainly axons), neuron-specific enolase (a marker of neurons, mainly somas), glial fibrillary acidic protein, and S-100 protein (markers of astrocytes). In addition, in patients with HSV-1 encephalitis CSF samples were collected serially before 7, 8-14, and 18-49 days and 3-10 months after the onset of neurological symptoms. In the acute stage of HSV-1 encephalitis we found markedly higher CSF levels of the cell damage markers than in patients with TBE. The concentration of cell damage markers in HSV-1 encephalitis decreased within 45 days after acute infection, except for neurofilament protein. The CSF concentrations of neurofilament protein increased during the second week, remained extremely high throughout the next month, and decrease thereafter. The changes in these markers of neuronal and glial destruction demonstrate the neuronal and astroglial cell damage during the first month after HSV-1 encephalitis. In contrast, most patients with TBE had signs only of slight astrogliosis, except for two patients with paresis.

Incidence of CSF abnormalities in siblings of multiple sclerosis patients and unrelated controls

We found that 19% (9/47) of healthy siblings of patients with clinically definite multiple sclerosis had an intrathecal immunological reaction with two or more 2 CSF-enriched oligoclonal bands (OCBs), in contrast to (4%) (2/50) unrelated healthy controls. Furthermore, in this group of nine healthy sibs the measles CSF IgG antibody titers were higher than that of the other sibs and that of controls. There were also differences in the serum titers for measles IgG antibody, which were higher in the group of all healthy sibs than in healthy volunteers, and (as with CSF titers) higher in the subgroup of healthy sibs with two or more 2 CSF-enriched OCBs than the other sibs. Thus a significant proportion of healthy siblings to MS patients have a partially hyperimmune condition similar to that occurring in MS, which in 19% manifested itself as an OCB reaction, in 9% as increased CSF measles IgG antibody titers, and in 21% as increased serum measles IgG antibody titers, these phenomena tending to occur in the same individuals. This condition is characterized by CSF-enriched OCBs with undefined specificity, although some increased antiviral reactivity is found both in the serum and CSF. While it needs further characterization, a genetic trait interacting with common infections is suggested. The recurrence risk of this condition is approximately five times higher than the 3-4% recurrence risk for manifest MS reported for sibs.

Cytoskeleton proteins in CSF distinguish frontotemporal dementia from AD

OBJECTIVE AND BACKGROUND

To investigate the CSF levels of tau and the light neurofilament protein (NFL) in patients with frontotemporal dementia (FTD) and other common dementia disorders as well as normal control subjects. Both proteins have been implicated in the pathophysiology of FTD.

METHODS

CSF levels of tau and NFL were investigated in 18 patients with FTD, 21 patients with early-onset AD (EAD), 21 patients with late-onset AD (LAD), and 18 age-matched control subjects.

RESULTS

Mean +/- SD CSF NFL levels were increased in patients with FTD (1442 +/- 1183 pg/mL; p < 0.05) and LAD (1006 +/- 727 pg/mL; p < 0.001) compared with control subjects (241 +/- 166 pg/mL) and in LAD compared with EAD (498 +/- 236 pg/mL; p < 0.05), and tended to be increased in FTD compared with EAD. CSF tau levels were increased in EAD (751 +/- 394 pg/mL; p < 0.01) and LAD (699 +/- 319 pg/mL; p < 0.01) compared with control subjects (375 +/- 170 pg/mL), and in EAD (p < 0.001) and LAD (p < 0. 01) compared with FTD (354 +/- 140 pg/mL). CSF NFL correlated positively with degree of cognitive impairment in FTD (r = 0.59; p < 0.05) and LAD (r = 0.61; p < 0.01). No significant differences were found in CSF NFL or CSF tau when comparing patients who did and did not possess the APOE-epsilon4 allele within each diagnostic group.

CONCLUSION

The results suggest a differential involvement of these cytoskeleton proteins in FTD and EAD, with NFL primarily involved in the pathophysiology of FTD and tau in that of EAD. The increase in CSF NFL found in LAD might reflect the white-matter degeneration found in a proportion of LAD cases.

Intrathecal release of nitric oxide and its relation to final brain damage in patients with stroke

The potential role of inflammatory mechanisms in the pathophysiology of ischemic brain damage has intensely been discussed. We have recently demonstrated that stroke patients display an intrathecal production of proinflammatory cytokines early after onset of symptoms. IL-1beta, one of these cytokines, stimulates the production of nitric oxide (NO), a potent inflammatory mediator. The aim of the present study was to investigate the intrathecal levels of nitrate, one of the main metabolites of NO in acute stroke and to relate its levels to brain damage. Stroke patients were prospectively studied with clinical evaluation, radiological assessment and analysis of intrathecal levels of nitrate by gas chromatography/mass spectrometry. In addition, simultaneous analyses of cytokines and of soluble Fas/APO-1 and bcl-2, two proteins regulating apoptosis, were performed. The intrathecal levels of nitrate were not significantly different in stroke patients compared to controls throughout the observation period. However, the intrathecal levels of nitrate increased significantly 3 months after stroke onset compared with the first 3 days. Interestingly, the levels of nitrate measured at stroke onset were negatively correlated to the final size of infarct volume (r = -0.69, p < 0.05) measured by MRI. In addition, patients with large infarcts displayed significantly (p = 0.008) lower levels of nitrate in cerebrospinal fluid compared to patients with small infarcts during the first 3 days after stroke onset. In contrast, the intrathecal levels of nitrate were significantly positively correlated (r = 0.79, p < 0. 001) to the neurological deficit and negatively correlated (r = -0. 76, p < 0.05) to bcl-2, a protein downregulating neuronal apoptosis, in the late stage of the stroke. Early NO production is associated with a smaller infarct volume, suggesting a protective effect, whereas late NO production is associated with severer neurological deficits, suggesting a neurotoxic effect. Treatment trials pertaining to modulate NO production in stroke should take into consideration the dual effect of NO on ischemic brain damage.

Intrathecal immune activation is associated with cerebrospinal fluid markers of neuronal destruction in AIDS patients

We analysed the relationship between cerebrospinal fluid (CSF) concentrations of the light subunit of the neurofilament protein (NFL, a marker of neurons, mainly axons), neopterin (a marker of immune activation), and quantitative HIV RNA levels in 47 patients with HIV-1 infection, 25 of whom had AIDS. In the AIDS patients, the mean levels of CSF NFL were high indicating neuronal destruction. The CSF NFL and the CSF neopterin concentrations were correlated in the subgroup of patients without CNS opportunistic infection (p < 0.05). There was no significant correlation between NFL and HIV RNA levels in CSF. In HIV seropositive patients without AIDS, only 3/22 had CSF NFL concentrations above the upper normal reference value. The results suggest that CNS neuronal destruction occurs frequently in patients with AIDS but rarely in those without AIDS, and that immune activation rather than the HIV viral load is associated with neurochemical signs of axonal destruction.

Protein markers in cerebrospinal fluid in experimental nerve root injury. A study of slow-onset chronic compression effects or the biochemical effects of nucleus pulposus on sacral nerve roots

STUDY DESIGN

Measurement of changes in cerebrospinal fluid concentrations of nerve tissue markers, total proteins, and immunoglobulin after compression of nerve root or application of nucleus pulposus in a pig model.

OBJECTIVES

To assess whether compression or application of nucleus pulposus to spinal nerve roots may cause increased levels of cerebrospinal fluid markers of nerve tissue damage and total proteins, and whether synthesis of immunoglobulins may be induced in cerebrospinal fluid.

SUMMARY OF BACKGROUND DATA

Previous studies have reported that there seems to be a relationship between elevated cerebrospinal fluid total protein concentrations, nerve tissue markers, clinical findings, and compression of the nerve root evaluated by radiologic changes in patients with sciatica.

METHODS

Subjects included 41 pigs, including 5 control animals. In two groups of experimental animals (n = 7; n = 5), an ameroid constrictor was slid onto the S1 nerve root. In two other groups (n = 7; n = 5), nucleus pulposus harvested from the L2-L3 disc was applied to the S1 nerve root. Two sham animal groups (n = 7; n = 5) underwent the same laminectomy. Twenty-one pigs underwent reoperation after 1 week, and 15 pigs after 4 weeks. A syringe was used to remove 3 mL of cerebrospinal fluid at L4-L5. Concentrations of total proteins, the light subunit of the neurofilament protein, S-100 protein, neuron-specific enolase, and glial fibrillary acidic protein were measured, and the presence of oligoclonal bands (immunoglobulins) were assayed in cerebrospinal fluid.

RESULTS

The pigs with compressed S1 nerve root had considerably higher neurofilament protein and total protein concentrations in their cerebrospinal fluid than the-control animals (P < 0.001 and P < 0.01, respectively) or the sham animals (P < 0.001 and P < 0.05) in the 1-week experiment. Nucleus pulposus did not induce a significant increase in concentrations of the different protein markers. The presence of oligoclonal bands in cerebrospinal fluid in the experimental groups did not differ between the control and sham animals.

CONCLUSIONS

The neurofilament protein and total protein concentrations in cerebrospinal fluid may have diagnostic importance in cases wherein clinical findings are not clearly related to the radiologic changes and vice versa. These protein markers also may be useful tools in different experimental models.

Cerebrospinal fluid markers of pathogenetic processes in vascular dementia, with special reference to the subcortical subtype

There is a need for improvement of the diagnosis of vascular dementia (VaD). Today, the clinician has to rely on clinical examination, history, and, possibly, brain imaging to identify cerebrovascular damage and other signs of VaD. The clinical diagnosis of subcortical VaD may be difficult because the clinical manifestation of this disorder is often similar to that of Alzheimer disease. There are also mixed forms of the two disorders. Biochemical diagnostic markers, which reflect the pathogenetic processes in the brain, would add to the accuracy of the diagnosis. There are some interesting candidate markers: the cerebrospinal fluid (CSF)/serum albumin ratio could be used to identify blood-brain barrier damage to the small intracerebral vessels, CSF sulfatide to identify ongoing demyelination of the white matter, CSF neuron-specific enolase to identify ongoing neuronal degeneration, and CSF tau protein and CSF neurofilament light protein to identify ongoing axonal degeneration. None of these potential markers is specific to subcortical VaD, but together and used in conjunction with the conventional diagnostic workup, they may be of diagnostic value.

Markers of nerve tissue injury in the cerebrospinal fluid in patients with lumbar disc herniation and sciatica

STUDY DESIGN

The light subunit of neurofilament protein, S-100 protein, neuron-specific enolase, and glial fibrillary acidic protein were determined in the cerebrospinal fluid in patients with lumbar disc herniation and in control patients.

OBJECTIVES

To determine whether nerve root injury caused by disc herniation increases the levels of nerve and glial cell injury markers in the cerebrospinal fluid.

SUMMARY OF BACKGROUND DATA

Markers of nerve tissue injury can be analyzed in the cerebrospinal fluid, allowing characterization of the cell types involved and the degree of disease in patients with neurologic disorders.

METHODS

Cerebrospinal fluid samples were obtained by preoperative lumbar puncture in patients who underwent surgery for lumbar disc herniation and in patients who underwent lower extremity surgery (control group), neurofilament protein (light subunit) and glial fibrillary acidic protein were analyzed by enzyme-linked immunosorbent assay and S-100 protein and neuron-specific enolase by radioimmunoassay and luminescence immunoassay, respectively. In the disc herniation group the concentrations of the four markers were evaluated regarding possible correlation to patient history, computed tomographic findings, and clinical findings.

RESULTS

Cerebrospinal fluid concentration of neurofilament protein (light subunit) and S-100 were increased in the disc herniation group compared with that in control subjects (1158 +/- 383 ng/L vs. 152 +/- 14 ng/L, P < 0.01; 1963 +/- 231 ng/L vs. 1003 +/- 152 ng/L, P < 0.05, respectively). No statistical differences in neuron-specific enolase and glial fibrillary acidic protein concentrations were observed between the groups. Disc herniation patients with fewer than 3 months' duration of subjective symptoms had higher neurofilament protein levels than did patients with longer duration. None of the markers was related to preoperative clinical or computed tomographic findings. Patients with persistent neurologic findings at follow-up 2-3 months after surgery had higher levels of neurofilament protein before surgery compared with-those without sequelae.

CONCLUSIONS

Patients with disc herniation and sciatica have increased concentrations of neurofilament protein and S-100 in the cerebrospinal fluid, which indicates damage of axons and Schwann cells in the affected nerve root.

Intrathecal expression of proteins regulating apoptosis in acute stroke

BACKGROUND AND PURPOSE

The neuronal death that accompanies an ischemic stroke has previously been attributed to a necrotic process. However, numerous studies in experimental models of ischemia have recently indicated that programmed cell death, also called apoptosis, may contribute to neuronal death. The aim of the present study was to investigate the intrathecal levels of proteins regulating apoptosis in acute stroke and to relate these levels to brain damage and to production of proinflammatory and anti-inflammatory cytokines.

METHODS

Thirty stroke patients were studied prospectively on days 0 to 4, 7 to 9, 21 to 26, and after day 90 with clinical evaluation, radiological assessment, and analysis of cerebrospinal fluid (CSF) levels of soluble (s) Fas/APO-1 and sbcl-2, 2 proteins that regulate apoptosis. In addition, analysis of the intrathecal levels of cytokines interleukin (IL)-1beta, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha was performed. Nineteen CSF samples from healthy subjects were used for control purposes. The patients were examined with MRI 1 to 3 months after stroke onset for measurement of infarct volume

RESULTS

Significantly decreased CSF levels of sFas/APO-1 were observed during the entire observation period, with a maximal decrease on day 21 after the onset of stroke. The intrathecal levels of sFas/APO-1 were significantly negatively correlated with the volume of brain infarct and with the neurological deficit 3 weeks and 3 months after the onset of the stroke. In addition, the intrathecal levels of sFas/APO-1 were significantly correlated with the levels of IL-1beta, IL-6, IL-10, and GM-CSF 3 weeks after the onset of the disease. The intrathecal levels of sbcl-2 were significantly decreased during the first 3 days after stroke onset and at the same time were positively correlated with the levels of IL-6 and tumor necrosis factor-alpha.

CONCLUSIONS

Our study demonstrates decreased intrathecal levels of proteins with antiapoptotic properties, suggesting that patients with acute stroke display a propensity toward apoptosis. Control of factors regulating apoptosis may lead to decreased delayed brain damage in stroke.

Decreased levels of S-100 protein in non-ulcer interstitial cystitis

Interstitial cystitis (IC) is a chronic debilitating condition which mainly affects women. Accumulated evidence indicates that IC is a heterogeneous syndrome. As compared to classic IC, the non-ulcer type of IC appears to be different concerning symptomatic, endoscopical and histological findings, as well as in response to various forms of treatment. S-100 is a neural protein considered to be located primarily in the axons. To explore further the neurogenic nature of the disease, we compared bladder wall S-100 content in controls and in patients with classic and non-ulcer IC. We noticed a decrease in S-100 content in non-ulcer IC as compared to controls. This may be an expression of altered peripheral innervation in non-ulcer IC, which, in turn, may be an indication of primary neurogenic etiology. The difference in S-100 content between classic and non-ulcer IC supports the hypothesis that they represent separate entities, which may explain differences in response to various treatments.

Increased cerebrospinal fluid ganglioside GD3 concentrations as a marker of microglial activation in HIV type 1 infection

Human immunodeficiency virus type 1 (HIV-1) invades the central nervous system (CNS) early in the infectious course. The predominant, productively infected cell type within the CNS is the microglial cell. We have analyzed the cerebrospinal fluid (CSF) levels of the ganglioside GD3, a microglia/macrophage and astrocyte marker, in 22 HIV-1-infected individuals at different stages of the disease, and in 44 age-matched HIV-negative, healthy controls. To distinguish between microglial/macrophage and astroglial involvement, the GD3 levels were compared with CSF levels of the glial fibrillary acidic protein (GFAp), which is expressed exclusively in astrocytes. A significantly higher mean CSF concentration of GD3 was found in HIV-1-infected patients compared to controls (56.7 and 40.1 nmol/L, respectively, p < 0.001). Seven of 22 HIV-1-infected patients had increased CSF levels of GD3 (above mean + 2 SD in controls), all but one of these had normal levels of GFAp, indicating a microglial activation or proliferation as the major source of the increased GD3 levels.

CSF neurofilament and glial fibrillary acidic protein in normal pressure hydrocephalus

We examined CSF levels of markers of neuronal degeneration and astrogliosis-the light subunit of the neurofilament triplet protein (NFL) and the glial fibrillary acidic protein (GFAP)-in 65 patients with normal pressure hydrocephalus (NPH). NFL was increased sixfold (864 +/- 1,538 [mean +/- SD] versus 156 +/- 81 ng/L; p < or = 0.001) and GFAP twofold (1,116 +/- 1,085 versus 637 +/- 295 ng/L; p < or = 0.01) in NPH patients compared with neurologically healthy age-matched controls. No correlation was found between any particular symptom or sign and GFAP levels in CSF. The levels of NFL, on the other hand, were higher in patients with severe symptoms compared with those with moderate or no symptoms. Furthermore, there was a correlation between a high level of NFL and gait disturbance, incontinence, psychometric incapability, and social dysfunction. A high preoperative NFL level was associated with favorable outcome after shunt surgery. This indicates that NFL is a marker of ongoing and possibly still-reversible axonal damage in NPH.

Increased serum levels of the S-100 protein are associated with hypoxic brain damage after cardiac arrest

BACKGROUND AND PURPOSE

Patients resuscitated from cardiac arrest have a high early mortality rate. Prognostic evaluation based on clinical observations is uncertain and would benefit from the use of biochemical markers of hypoxic brain damage. The astroglial protein S-100 is an established biochemical marker of central nervous system injury. The purpose of the present study was to validate the use of serum determinations of S-100 with regard to outcome after cardiac arrest.

METHODS

Levels of serum S-100 were measured with a radioimmunoassay in 41 patients the first 3 days after out-of-hospital cardiac arrest. The main outcome variable was fatal outcome within 14 days.

RESULTS

S-100 levels were increased after cardiac arrest compared with controls with the highest levels observed the first day. S-100 levels day 1 and 2 correlated to the degree of coma as well as to the time of anoxia. Seventeen patients died within 14 days after the cardiac arrest. The deceased patients had increased S-100 levels on days 1 through 3 compared with survivors. All patients (100%) with an S-100 level of > or =0.2 on day 2 after the cardiac arrest died within 14 days, and 89% of the patients with levels below this limit value survived (positive and negative predictive values). The corresponding predictive values on day 1 were 71% and 85%, respectively.

CONCLUSIONS

The present study shows that hypoxic brain damage after cardiac arrest can be estimated by measurement of serum S-100 concentrations. The method can be used in early prognostic evaluation of short-term outcome after cardiac arrest.

Increased cerebrospinal fluid levels of neurofilament protein in progressive supranuclear palsy and multiple-system atrophy compared with Parkinson's disease

More reliable tools are needed for the differentiation of Parkinson's disease (PD) from other parkinsonian disorders. The neurofilament protein (NFL) and the glial fibrillary acidic protein (GFAP) are main structural proteins of axons and fibrillary astroglial cells. By using enzyme-linked immunosorbent assays, these proteins were quantified in the cerebrospinal fluid (CSF) of 49 patients referred to the Department of Neurology for diagnostic consideration or treatment of parkinsonism of different etiologies. All patients were first diagnostically evaluated by strict clinical criteria. The procedure included a neurologic and neuro-ophthalmologic examination as well as computed tomography or magnetic resonance imaging. These were performed independently and in advance of the CSF analysis. A total of 19 patients were diagnosed as having PD, 12 had progressive supranuclear palsy (PSP), and 10 had multiple-system atrophy (MSA). Eight were diagnosed as having other diseases, such as arteriosclerotic parkinsonism and undefined parkinsonian syndromes. The content of NFL was significantly higher both in the PSP group (p < 0.001) and in the MSA group (p < 0.0001) compared with the PD group. The high values of NFL indicate an ongoing neuronal degeneration affecting mainly the axonal compartment in the PSP and MSA groups, whereas there was no difference in glial involvement as measured by GFAP in the PD, PSP, and MSA groups. There was a relation between high CSF levels of NFL in the various patient groups and the occurrence of pyramidal symptoms (p < 0.001), possibly reflecting the axonal damage to the corticospinal tract. Furthermore, mortality at 24-month follow up was associated with high NFL levels (p < 0.01). We conclude that analysis of NFL in CSF may become useful in the differential diagnosis of parkinsonian syndromes.

Intrathecal release of pro- and anti-inflammatory cytokines during stroke

A growing body of evidence points out the potential role of inflammatory mechanisms in the pathophysiology of ischaemic brain damage. We have recently demonstrated that stroke patients display an intrathecal production of proinflammatory cytokines, such as IL-1beta and IL-6 already within the first 24 h after the beginning of symptoms (Tarkowski et al., 1995). The aim of the present study was to investigate patterns of local inflammatory responses as a consequence of acute stroke. Thirty stroke patients were studied prospectively on days 0-3, 7-9, 21-26 and after day 90 with clinical evaluations, radiological assessments and analysis of cerebrospinal fluid (CSF) cytokine levels. In addition, 15 healthy control CSF samples were used. Significantly increased CSF levels of IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-10 were observed early during the stroke with a peak on day 2 for the proinflammatory cytokines IL-8 and GM-CSF, and on day 3 for the immunoregulatory cytokine IL-10. Patients with a brain infarct predominantly located in the white matter showed significantly higher levels of IL-8 in CSF than patients with an infarct mainly located in the grey matter. Also, high levels of intrathecal tumour necrosis factor-alpha (TNF-alpha) were associated with the presence of white matter disease. Our study demonstrates an intrathecal production of proinflammatory and immunoregulatory cytokines in patients with stroke, supporting the notion of localized immune response to the acute brain lesion. A better understanding of the inflammatory response in stroke may lead to new treatment strategies.

Extracellular glial fibrillary acidic protein and amino acids in brain regions of patients with subarachnoid hemorrhage--correlation with level of consciousness and site of bleeding

The extracellular fluid of two cortical regions was investigated in eight patients who underwent surgery for subarachnoid hemorrhage within 7-96 h after the rupture of an arterial aneurysm. Microdialysis samples, collected from the cortex of the ipsilateral gyrus rectus and temporal lobe for 52-127 h, were analyzed with respect to amino acids and the glial fibrillary acidic protein. In agreement with a previous study, an inverse relation was observed between total amino acid concentration and the level of consciousness. We also found that the concentration of glial fibrillary acidic protein was higher close to the bleeding site. Furthermore, we observed specific changes in the concentration of the protein and certain amino acids which coincided with clinical events such as increased intracranial pressure, vasospasm, ischemia and infarction. Finally, the concentrations of taurine may corroborate its function as an osmoequivalent.

Glial fibrillary acidic protein is increased in the cerebrospinal fluid of preterm infants with abnormal neurological findings

Glial fibrillary acidic protein (GFAP) is the structural protein of the intermediate filament of astroglia. The aims of the present study were to examine GFAP in the cerebrospinal fluid (CSF) of preterm infants at different postmenstrual ages and to evaluate the potential of GFAP to predict abnormal neurodevelopmental outcome. GFAP increased in correlation with postmenstrual age in preterm infants (n = 17) and full-term infants (n = 9). The levels were five times higher in preterm infants (n = 10) with an abnormal neonatal course and/or an abnormal neurological outcome than in healthy preterm infants. The positive predictive value of a GFAP higher than the 98th percentile of normal infants was 69%, while a GFAP level below this limit invariable predicted a good outcome. Simultaneously analysed noradrenaline, hypoxanthine and glutamate did not differ between the groups. We conclude that CSF GFAP increases with maturity and that CSF GFAP appears to be a promising marker for perinatal brain damage.

Early intrathecal production of interleukin-6 predicts the size of brain lesion in stroke

BACKGROUND AND PURPOSE

We have previously demonstrated that stroke influences systemic immune responses. The aim of the present study was to investigate patterns of local inflammatory response as a consequence of acute stroke.

METHODS

Thirty stroke patients were studied prospectively on days 0 to 3, 7 to 9, 21 to 26, and after day 90 with clinical evaluations, radiological assessments, and analysis of serum and cerebrospinal fluid cytokine levels.

RESULTS

Significantly increased levels of interleukin-6 (IL-6) in cerebrospinal fluid (P < .001) were observed in virtually all patients studied compared with healthy control subjects. This increase was observed during the whole observation period but was significantly more pronounced within the first days after stroke onset, with a peak level on days 2 and 3. This initial increase was significantly correlated (r = .65, P = .002) with the volume of infarct measured by MRI 2 to 3 months later. Serum levels of IL-6 in stroke patients were significantly lower than cerebrospinal fluid levels of IL-6 (P = .013) and did not display any significant correlation to the size of the brain lesion. Also, increase in intrathecal but not systemic production of IL-1 beta was observed early during the stroke. Only minor increases of cerebrospinal fluid interferon-gamma levels were observed in two patients.

CONCLUSIONS

Our study demonstrates an intrathecal production of IL-6 and IL-1 beta in patients with stroke, supporting the notion of localized inflammatory response to acute brain lesion. In addition, the significant correlation between early intrathecal production of IL-6 and the subsequent size of the brain lesion can be used as a prognostic tool, predicting the size of the brain damage before it is possible to accurately visualize it with radiological methods.

Glial fibrillary acidic protein in the cerebrospinal fluid: a possible indicator of prognosis in full-term asphyxiated newborn infants?

Glial fibrillary acidic protein (GFAP) is the structural protein of intermediate filaments in astroglia. GFAP has extensively been used as a marker of gliosis in neuropathology. It also appears in excessive amounts in the cerebrospinal fluid in various acute brain disorders. Hypoxic-ischemic encephalopathy after perinatal asphyxia is a condition in which levels of GFAP could be expected to be elevated if brain cell damage occurs. We examined levels of GFAP by a sensitive ELISA in the cerebrospinal fluid of full-term infants between 12 and 48 h after birth. Cerebrospinal fluid-GFAP increased 5-fold in infants after perinatal asphyxia compared with a reference group (675 versus 137 ng/L, p < 0.001). The levels of GFAP also increased gradually in accordance with the severity of the neurologic symptoms ranked as degree of hypoxic-ischemic encephalopathy. We conclude that the cerebrospinal fluid levels of GFAP might be an important adjunct in the neonatal assessment of infants subject to perinatal asphyxia, and together with other neuronal or glial proteins, it might also help in defining temporal relationships in asphyxia.

Analysis of glial fibrillary acidic protein in the cerebrospinal fluid of children investigated for encephalopathy

The clinical application of a newly developed highly sensitive ELISA method (20) to assay glial fibrillary acidic protein (GFAP) in the cerebrospinal fluid (CSF) was investigated in children and adolescents with neurological disorders. GFAP analysis was explored as a tool to differentiate disorders with ongoing astrocytosis. A consecutive series of 34 subjects, 17 boys and 17 girls, with nonprogressive and progressive neurological encephalopathies was compared to 10 healthy controls. The mean CSF GFAP concentration of the controls was 60.6 +/- 54 ng/l (SD). The group of 24 subjects (12 boys and 12 girls) with progressive neurologic disorders had higher mean CSF GFAP levels than the group of 10 subjects (5 boys and 5 girls) with non-progressive disorders, 222.6 +/- 186 and 127.5 +/- 86 ng/l, respectively. The progressive encephalopathies differed significantly from controls (p < 0.01) while the non-progressive did not. The mean GFAP concentration of the epilepsy cases (n = 18) and non-epilepsy cases (n = 16) was 212.9 +/- 196 and 174.0 +/- 132 ng/l, respectively. The epilepsy cases differed significantly from controls which could be explained by the dominance of progressive cases (15 out of 18).(ABSTRACT TRUNCATED AT 250 WORDS)

Glial fibrillary acidic protein in the cerebrospinal fluid of children with autism and other neuropsychiatric disorders

The cerebrospinal fluid (CSF) of 47 children and adolescents with autism was analyzed for the contents of two astroglial proteins, the glial fibrillary acidic protein (GFA) and S 100. The results were contrasted with those obtained in similarly aged cases with other neuropsychiatric disorders (n = 25) and in normal children (n = 10). S-100 did not discriminate the groups from each other. However, GFA in autism and autistic-like conditions was at a level almost three times that in the normal group. The results could implicate gliosis and unspecific brain damage in autism. An alternative model would be increased synapse turnover regardless of underlying cause.

The IOP-IOL. A probe into the eye

The intraocular lens (IOL) implant can be looked upon as a probe into the space of the eye. Adapting that view, it is logical to furnish the IOL-probe with biomedical sensors that would explore its environment. A sensor is presented for continuous monitoring of intraocular pressure (IOP), incorporated in the haptics of an IOL. The sensor consists of a capacitative spiral circuit, needing no energy, correlating its resonance frequency to the actual IOP. This resonance frequency is remotely and non-invasively detected by an external device located in a spectacle frame.

Immunocytochemical investigations on the presence of neuron-specific antibodies in the CSF of Parkinson's disease cases

The CSF and sera of 7 patients with Parkinson's disease were investigated immunocytochemically, in order to see if antibodies were present which recognized DA-ergic cell bodies in glutaraldehyde fixed rat brain. In 2 patients a marked labeling of DA-ergic neurons in the substantia nigra was observed, identified by anti-DA antiserum and by 6-OHDA induced degeneration, but also other neurons in the ventral mesencephalon were recognized. The other patients were weakly positive or negative. Sera gave unspecific labelling of all neurons. In one patient the sub-classes of IgG were investigated and found to be of IgG3 (labeling nerve terminals) and of IgG1-2, low affinity type (recognizing perikarya). The epitopes recognized have not been identified, but are unlikely to be DA-like, since blocking experiments and ELISA-tests gave negative results. The possible clinical importance of the results are discussed.

Antibodies in cerebrospinal fluid of some Alzheimer disease patients recognize cholinergic neurons in the rat central nervous system

The etiology of Alzheimer disease is unclear. However, immunological aberrations have been suggested to be critical factors in the pathogenesis of this neurodegenerative disease. This study was carried out to investigate if cerebrospinal fluid (CSF) from Alzheimer disease patients contains antibodies that recognize specific neuronal populations in the rat central nervous system. The results indicate that in a subgroup of patients this is indeed the case. The antibodies reported in this study have the following properties: (i) they recognize neuronal populations and components in the medial septum and spinal motor neurons in rats perfused with a mixture that fixes small neurotransmitter molecules; (ii) adsorption of the patient CSF with staphylococcal protein A-Sepharose and using a polyclonal antiserum against human IgG3 indicates that the immunocytochemical reaction in these brain regions is mainly due to the subclass IgG3; and (iii) the CSF immunocytochemical reaction is blocked by preincubation of the sections with a rabbit anti-acetylcholine antiserum. These results provide evidence that antibodies in the CSF of some, but not all, Alzheimer disease patients recognize acetylcholine-like epitopes in cholinergic neurons in the rat central nervous system.

Aspects of abstinence after morphine ingestion

Sprague-Dawley male rats were intoxicated with morphine, using an ingestion method where exposed and control rats received equivalent amounts of calories and nutrients. The degree of physical dependence on morphine was demonstrated by studying and quantifying abstinence symptoms after withdrawal or after administration of opiate antagonists. The aims of the study were (1) to further enlighten the specificity and validity of the intoxication method concerning physical dependence, and (2) to determine whether some of the abstinence signs might be of value to facilitate quantitation of the degree of physical dependence on morphine, with diet and fluid intake being maintained under control. Withdrawn rats showed a decreased fluid diet intake and a body weight loss, the latter partly due to anorexia. Other mild abstinence signs were irritation, tremor and some motor excitation. The body weight loss during the first day of morphine withdrawal was proportional to the accumulated drug dose (between 25 and 300 mg morphine PO/kg b.wt.). However, prolonged morphine treatment on one dose (340 mg/kg b.wt.) did not reinforce the body weight changes caused by morphine withdrawal. The succeeding weight gain some days after morphine withdrawal was not entirely dependent on the amount of fluid diet intake. Methadone was shown to partially block the decrease in diet intake and the weight loss seen during morphine withdrawal. The naloxone-precipitated withdrawal symptoms were motor excitation, cholinergic signs, body weight loss, diarrhoea and decreased diet intake. The weight loss 2 hr after naloxone administration to long-term intoxicated rats was proportional to the naloxone dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic effects of dichloromethane on amino acids, glutathione and phosphoethanolamine in gerbil brain

Mongolian gerbils were exposed to dichloromethane for three months by continuous inhalation at 210 ppm. Total free tissue amino acids, glutathione, and phosphoethanolamine were determined in the vermis posterior of the cerebellum and the frontal cerebral cortex. These two brain areas were chosen because humans occupationally exposed to dichloromethane have shown abnormalities in the electroencephalogram of the frontal part of the cerebral cortex. This study showed that long-term exposure of gerbils to dichloromethane (210 ppm) for three months leads to decreased levels of glutamate, gamma-aminobutyric acid, and phosphoethanolamine in the frontal cerebral cortex, while glutamine and gamma-aminobutyric acid are elevated in the posterior cerebellar vermis.

Neurotransmitter uptake in various brain regions of chronically morphinized rats

Rats were long-term morphine-intoxicated by a fluid-diet model ensuring an equal nutrient intake in morphinized and control rats. Uptake of neurotransmitters and D-ala2-met5-enkephalinamide (Enk) was studied in the particulate fractions (obtained at 10,000 g) from well defined brain regions of long-term intoxicated and morphine withdrawn rats. In control animals the accumulation of [3H]glutamate and [3H]gamma-aminobutyric acid (GABA) reached the highest tissue/medium (T/M) ratio values, 30-120, in the regions studied while monoamine T/M values were 2-10. No active uptake of [3H]Enk could be demonstrated. Striatum showed the most evident modifications in neurotransmitter uptake. In this region the equilibrium T/M ratio for [3H]glutamate and [3H]GABA was significantly lower in intoxicated rats versus controls. Moreover, the T/M ratio for [3H]5-hydroxytryptamine (5-HT) was lower, while that for [3H]dopamine (DA) was higher in abstinent rats in comparison with the controls. [3H]glutamate and [3H]GABA uptakes were also significantly lower, respectively, in frontal cortex, hippocampus and brain stem in intoxicated rats, while [3H]5-HT uptake was significantly lower in hypothalamus after morphine withdrawal. The possible involvement of the endogenous opioid system in the etiology of the alterations is discussed.

Immunohistochemical distribution of S-100 antigen in the urinary system of man and rat

The immunohistochemical distribution of S-100, a protein originally isolated from the brain, has been investigated at the light and electron microscopic levels in rat and man urinary systems. In both species the antigen essentially exhibited the same location, restricted, with different degrees of staining, to certain cells in the kidney, i.e. collecting tubules, thin limbs of Henle's loop and renal papillae.

Differentiation markers (S-100, GFAP, NSE and D2) in fetal rat brain cells during malignant transformation in cell culture

Malignant cell lines obtained by ethylnitrosourea (EtNU)-induced transformation of fetal rat brain cells in culture express protein markers of different types of neural cells. These are the nervous system-characteristic S-100 protein; glial fibrillary acidic protein (GFAP); neuron-specific-enolase (NSE), and the D2-cell adhesion molecule. S-100 protein was absent in fetal brain cells in culture, but gradually appeared in the later stages of malignant transformation and further increased at onset of rapid growth of atypical cells (stage IV). GFAP and D2 were weakly expressed in primary fetal brain cells and did not change throughout malignant transformation. NSE was present in both normal and carcinogen-treated fetal brain cells, and increased at later stages of malignant transformation. From stage III (40-100 days) some cultures were strongly positive and some negative, and the same was seen in the resulting tumorigenic cells about 100 days later. In conclusion the stepwise process of malignant transformation of brain cells in culture ended with a stable phenotype of cells capable of expressing varying types of differentiation markers. The presence of these markers in rat brain cells undergoing malignant transformation may indicate that EtNU given at 18th days of gestation is acting on multipotent neuroectodermal cells.

S-100 alpha-like immunoreactivity in tubules of rat kidney. A clue to the function of a "brain-specific" protein

The localization of the alpha and beta subunits of S-100 protein was studied in normal tissue where the identification of three subclasses of S-100 containing cells was derived: i) cells that contain both alpha and beta subunits; ii) cells that contain only the alpha subunit; and iii) cells that contain only the beta subunit. In this study monospecific antibodies against the S-100 alpha and beta subunits were used to characterize the S-100-like immunoreactivity in the rat kidney: Certain cells in the distal nephron, i.e., the connecting piece, collecting ducts, and the thin limb of Henle's loop, contained S-100 alpha immunoreactivity. Proximal tubules, the thick ascending limb of Henle's loop, the distal tubules, and the juxtaglomerular apparatus were negative. No S-100 beta immunoreactivity was found in kidney tubules. However, Schwann cells of renal pelvic nerves contained S-100 beta immunoreactivity. The presence of S-100 alpha antigen in certain cells of the kidney gives further support to the assumption that the alpha subunit of S-100a is related to cells that are highly involved in pH, electrolyte, and water regulation.

Differential localization of "brain-specific" S-100 and its subunits in rat salivary glands

In the rat, the S-100 antigens in the submandibular gland were found to be immunochemically identical with those in the brain (glial cells) when compared using crossed immunoelectrophoresis. Specific antibodies against the S-100a non-beta and against the S-100 beta subunit were prepared from antibodies against crude S-100 protein and from S-100 components (S-100a and b) by affinity chromatography. In the rat salivary glands a differential distribution of subunit immunoreactivity was clearly evidenced using indirect immunofluorescence. Certain intercalated duct cells of the submandibular gland as well as Schwann cells contained the S-100 beta subunit immunoreactivity exclusively, while other duct cells in parotid, submandibular, and sublingual glands contained S-100a non-beta subunit immunoreactivity. Both subunits were present in astrocytes and ependymal cells. The immunocytochemical localization of alpha and beta subunits is a promising technique for the classification of various types of S-100-containing cells.

S-100 protein in melanocytic tumors. An immunohistochemical investigation of benign and malignant melanocytic tumors and metastases of malignant melanoma and a characterization of the antigen in comparison to human brain

An immunohistochemical investigation regarding the presence of S-100 protein in benign and malignant, primary and metastatic melanocytic tumors is reported. The studied series consisted of 15 benign nevi, 3 blue nevi, 4 juvenile melanomas, 1 balloon cell nevus, 30 primary malignant melanomas of skin, mucous membranes and conjunctiva and 30 metastatic malignant melanomas. The immunohistochemical analysis showed positive staining for S-100 protein within the majority of the tumor cells in all benign tumors examined, except the balloon cell nevus, as well as in all the primary and metastatic malignant melanomas, including low-differentiated epitheloid or spindle-cell types without demonstrable melanin pigment. The results indicate that S-100 protein is a valuable marker for melanocytic tumors, especially in the fairly frequent dilemma of malignant melanoma presenting as a solitary non-pigmented metastasis of uncharacteristic light-microscopic appearance, and without known primary tumor. A characterization and quantification of the S-100 protein immunoreactivity in 5 metastatic malignant melanomas is presented. Using immuno-electrophoresis, the presence of 3 antigenic S-100 determinants was demonstrated within homogenates from the malignant melanomas, including the previously characterized S-100 A (alpha/beta) and S-100 B (beta/beta), and suggesting the presence of a hitherto undescribed variant of S-100 protein, possibly consisting of 2 alpha-subunits. Using rocket immuno-electrophoresis, the amount of S-100 protein was estimated.