Oxysterols and multiple sclerosis: Physiopathology, evolutive biomarkers and therapeutic strategy

Multiple sclerosis is an autoimmune disease that affects the central nervous system. Dysfunction of the immune system leads to lesions that cause motor, sensory, cognitive, visual and/or sphincter disturbances. In the long term, these disorders can progress towards an irreversible handicap. The diagnosis takes time because there are no specific criteria to diagnose multiple sclerosis. To realize the diagnosis, a combination of clinical, biological, and radiological arguments is therefore required. Hence, there is a need to identify multiple sclerosis biomarkers. Some biomarkers target immunity through the detection of oligoclonal bands, the measurement of the IgG index and cytokines. During the physiopathological process, the blood-brain barrier can be broken, and this event can be identified by measuring metalloproteinase activity and diffusion of gadolinium in the brain by magnetic resonance imaging. Markers of demyelination and of astrocyte and microglial activity may also be of interest as well as markers of neuronal damage and mitochondrial status. The measurement of different lipids in the plasma and cerebrospinal fluid can also provide suitable information. These different lipids include fatty acids, fatty acid peroxidation products, phospholipids as well as oxidized derivatives of cholesterol (oxysterols). Oxysterols could constitute new biomarkers providing information on the form of multiple sclerosis, the outcome of the disease and the answer to treatment.

Changes in the cerebrospinal fluid lipid profile following subarachnoid hemorrhage in a closed cranium model: Correlations to cerebral vasospasm, neuronal cell death and Interleukin-6 synthesis. A pilot study

BACKGROUND

Phospholipids and sphingolipids are cell membrane components, that participate in signaling events and regulate a wide variety of vital cellular processes. Sphingolipids are involved in ischemic stroke pathophysiology. Throughout cleavage of membrane sphingomyelin by sphingomyelinase in stroke patients, it results in increased Ceramide (Cer) levels in brain tissue. Different studies showed the evidence that sphingomyelinase with Cer production induces expression of interleukin (IL)-6 and have vasoconstrictive proprieties. With this study, we intend to evaluate cerebrospinal fluid (CSF) lipid profile changes in a rabbit closed cranium subarachnoid hemorrhage (SAH) model.

METHODS

A total of 14 New Zealand white rabbits were randomly allocated either to SAH or sham group. In the first group SAH was induced by extracranial-intracranial shunting from the subclavian artery into the cisterna magna. Intracranial pressure (ICP) and arterial blood pressure were continuously monitored. Digital subtraction angiography of the basilar artery, CSF and blood samples were performed at day 0 pre SAH and on day 3 post SAH. The amount of IL-6 and various lipids in CSF were quantified using ELISA and Liquid Chromatography-Mass Spectrometry respectively. Cell death was detected in bilateral basal cortex, hippocampus (CA1 and CA3) using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL).

RESULTS

SAH Induction led to acute increase of ICP and increased delayed cerebral vasospasm (DCVS). At follow up CSF IL-6 levels showed a significant increase compared to baseline. Between baseline and follow up there were no significant differences in any of the measured CSF Lipids irrespective of subgroups. No relevant correlation was found between IL-6 and any of the sphingolipids. We found a correlation between baseline and follow up for the phospholipids phosphatidylethanolamine and phosphatidylcholine.

CONCLUSIONS

Neuronal apoptosis, DCVS and IL-6 seems not to be related to changes in CSF lipid profiles except for PEA and PC in a rabbit closed cranium SAH model.

Cerebrospinal fluid lipidomics: effects of an intravenous triglyceride infusion and apoE status

INTRODUCTION

High-fat diets increase risk for Alzheimer's disease, but individuals with the risk gene APOE ε4 (E4) paradoxically have improved memory soon after high fat feeding. Little is known about how dietary lipids affect CNS lipids, especially in older adults.

OBJECTIVES

We analyzed the lipidomic signature of cerebrospinal fluid (CSF) in older adults who underwent both a saline and TG infusion. We further analyzed these data by E4 carrier status.

METHODS

Older adults (n = 21, age 67.7 ± 8.6) underwent a 5-h TG and saline infusion on different days in random crossover design; lumbar CSF was collected at the end of the infusion. Lipids were extracted using dichloromethane/methanol and 13 classes of lipids analyzed using the Lipidyzer platform consisting of an AB Sciex 5500 MS/MS QTraps system equipped with a SelexION for differential mobility spectrometry (DMS). Multiple reaction monitoring was used to target and quantify 1070 lipids in positive and negative ionization modes with and without DMS.

RESULTS

The TG infusion increased total lipids in the CSF, including the appearance of more lipids at the detection limit in the TG samples compared to saline (Chi square p < 0.0001). The infusion increased the total level of diacylglycerols and lysophosphatidylcholines and reduced dihydroceramides. Of the possible 1070 lipids detectable, we found 348 after saline and 365 after TG infusion. Analysis using MetaboAnalyst revealed 11 specific lipids that changed; five of these lipids decreased after TG infusion, and four of them differed by E4 status, but none differed by cognitive diagnosis or sex.

CONCLUSION

These results in older adults show that blood lipids affect lipid profiles in CSF and such profiles are modified by APOE status. This suggests that how the CNS handles lipids may be important in the AD phenotype.

CNS, lung, and lymph node involvement in Gaucher disease type 3 after 11 years of therapy: clinical, histopathologic, and biochemical findings

A Caucasian male with Gaucher disease type 3, treated with continuous enzyme therapy (ET) for 11 years, experienced progressive mesenteric and retroperitoneal lymphadenopathy, lung disease, and neurological involvement leading to death at an age of 12.5 years. Autopsy showed significant pathology of the brain, lymph nodes, and lungs. Liver and spleen glucosylceramide (GluCer) and glucosylsphingosine (GluS) levels were nearly normal and storage cells were cleared. Clusters of macrophages and very elevated GluCer and GluS levels were in the lungs, and brain parenchymal and perivascular regions. Compared to normal brain GluCer (GC 18:0), GluCer species with long fatty acid acyl chains were increased in the patient's brain. This profile was similar to that in the patient's lungs, suggesting that these lipids were present in brain perivascular macrophages. In the patient's brain, generalized astrogliosis, and enhanced LC3, ubiquitin, and Tau signals were identified in the regions surrounding macrophage clusters, indicating proinflammation, altered autophagy, and neurodegeneration. These findings highlight the altered phenotypes resulting from increased longevity due to ET, as well as those in poorly accessible compartments of brain and lung, which manifested progressive disease involvement despite ET.

Lipidomic analysis of cerebrospinal fluid by mass spectrometry-based methods

Lipids are natural substances found in all living organisms. Essential to the integrity of cell membranes, they also have many biological functions linked to energy storage and cell signaling, and are involved in a large number of heterogeneous diseases such as cancer, diabetes, neurological disorders, and inherited metabolic diseases. Lipids are challenging to analyze because of their huge structural diversity and numerous species. Up to now, lipid analysis has been achieved by targeted approaches focusing on selected families and relying on extraction protocols and chromatographic methods coupled to various detectors including mass spectrometry. Thanks to the technological improvements achieved in the fields of chromatography, high-resolution mass spectrometry and bioinformatics, it is possible to perform global lipidomic analyses enabling the concomitant detection, identification and relative quantification of many lipid species belonging to different families. The aim of this review is to focus on mass spectrometry-based methods to perform lipid and lipidomic analyses and on their application to the analysis of cerebrospinal fluid.

In vitro, high-resolution 1H and 31P NMR based analysis of the lipid components in the tissue, serum, and CSF of the patients with primary brain tumors: one possible diagnostic view

In vitro, high-resolution (1)H and (31)P NMR based qualitative and quantitative analyses of the lipid components of the tissue, serum, and CSF of patients with primary brain tumors were performed. Proton NMR spectra of the lipid extract of serum (blood specimen collected before the surgical procedure) and surgically discarded tissue showed that the total cholesterol (T.CHOL) and choline containing phospholipids (PL) were significantly higher in quantity in medulloblastoma and glioblastoma multiforme as compared to normal subjects. Serum lipid extracts of grade II/ III gliomas showed a higher quantity of PL than normal subjects. Cholesterol esters (CHOLest) were detectable in the tissue lipid extract of the patients with tumors and absent in normal tissue. There was a reduction in the quantity of CHOLest in the serum lipid extract of the tumor patients as compared to normal subjects. Ratio of PL to T.CHOL in serum lipid extract showed a significant difference between different grades of tumors versus normal subjects, while, a significant difference was observed only in medulloblastoma versus normal subjects in tissue lipid extract. Ratio of CHOL to CHOLest distinguishes the different grades of tumors versus normal subjects as well as between different grades of tumors (except medulloblastoma versus glioblastoma). The ratio of the Ph (total phospholipids except phosphatidylcholine) to PC (phosphatidylcholine) in (31)P NMR based study showed a significant difference in all grades of tumors (except medulloblastoma) in normal subjects in tissue lipid extract as well as between different grades of tumors. Medulloblastoma could be differentiated from glioblastoma as well as from normal subjects in serum lipid extract by the ratio of the Ph to PC. Proton NMR spectra of the lipid extract of CSF showed that the CHOL, CHOLest, and PL were present in the patients with tumors, although these were absent in the patients with meningitis, motor neuron disease, and mitochondrial myopathies as well as in normal subjects. PL and T.CHOL provided discrimination between different grades of tumors (except glioblastoma versus medulloblastoma) in the lipid extract of the CSF. This study suggests the role of lipid estimation in CSF and serum as a complementary diagnostic tool for the evaluation of brain tumors preoperatively. NMR-based lipid estimation of post-surgical tumor tissue may also contribute to differentiating the tumor types.

Combining lipidomics and proteomics of human cerebrospinal fluids

Lipids from dietary sources or from de novo synthesis are transported while bound to proteins to other tissues where they are used for cell membrane synthesis or stored for energy generation. In cell membranes or in plasma, lipids can undergo several modifications that are important in cell function. Several proteins orchestrate the transport, biosynthesis, and modification of lipids. Thus, the intersection of lipids and proteins is important in human metabolic pathways. Recent advances in mass spectrometry and bioinformatics have made it possible to obtain compositional (structural and functional) data of lipid molecular species and proteins in biological samples. This combination of lipidomics and proteomics is advantageous because it allows us to better define biochemical pathways, discover new drug targets, and better understand the pathophysiology of several diseases.

Cerebrospinal Profiling of Proteins, Lipids, Small Molecules, and Elements: Application to the Study of Migraine Pathophysiology

BACKGROUND AND OBJECTIVES

The fundamental reason that the migraine phenotype is experienced by sufferers and not by the more fortunate populace is not known. We believe a common biochemical pathway is involved, and are attempting to reveal this by using an objective and broad survey of molecular composition, rather than the conventional hypothesis-driven approaches that are narrowly focused and subjective.

METHODS

This article discusses the application of CSF bioanalysis in a clinical sample and summarizes preliminary findings, which are described more fully in papers currently in press.

RESULTS

In migraineurs during a migraine attack, compared with a migraine-free period, changes have been documented in the concentrations of specific proteins, lipids, small molecules, and elements in the CSF The degree to which these changes are specific to migraine remains to be determined.

CONCLUSIONS

As the CSF profiles for proteins, lipids, small molecules, and elements become better delineated in both healthy individuals and in disease states such as migraine, measurement of changes in CSF composition will provide the potential for improving diagnosis, correlating molecular events with symptoms, developing new therapeutic strategies, and enhancing the ability to monitor the results of therapy.

Characterization and direct quantitation of sphingoid base-1-phosphates from lipid extracts: a shotgun lipidomics approach

Here, we have extended shotgun lipidomics for the characterization and quantitation of sphingosine-1-phosphate (S1P) and dihydrosphingosine-1-phosphate (DHS1P) in crude lipid extracts in the presence of ammonium hydroxide by using precursor ion scanning of m/z 79.0 (corresponding to [PO(3)](-)) in the negative-ion mode. It is demonstrated that a broad linear dynamic range for the quantitation of both S1P and DHS1P and a detection limit at low amol/mul concentration are achieved using this approach. The developed method for the quantitation of sphingoid base-1-phosphates is generally simpler and more efficient than other previously published methods. Multiple factors influencing the quantitation of sphingoid base-1-phosphates, including ion suppression, extraction efficiency, and potential overlapping with other molecular species, were examined extensively and/or are discussed. Mass levels of S1P and DHS1P in multiple biological samples, including human plasma, mouse plasma, and mouse brain tissues (e.g., cortex, cerebellum, spinal cord, and brain stem), were determined by the developed methodology. Accordingly, this technique, as a new addition to shotgun lipidomics technology, will be extremely useful for understanding the pathways of sphingolipid metabolism and for exploring the important roles of sphingoid base-1-phosphates in a wide range of physiological and pathological studies.

Ruptured spinal dermoid cyst with disseminated intracranial fat droplets

Fat droplets in the cerebrospinal fluid (CSF) is a well-known complication of ruptured intracranial dermoid tumours. We report an unusual case of a ruptured spinal dermoid tumour. MR images showed a tethered spinal cord and an intramedullary fat-containing mass. Fat droplets were revealed in the ventricles and the cisternal spaces on brain CT and brain MR. In the English literature, a ruptured spinal dermoid tumour accompanying a tethered spinal cord is extremely rare.

Identification of disease markers in human cerebrospinal fluid using lipidomic and proteomic methods

Lipids comprise the bulk of the dry mass of the brain. In addition to providing structural integrity to membranes, insulation to cells and acting as a source of energy, lipids can be rapidly converted to mediators of inflammation or to signaling molecules that control molecular and cellular events in the brain. The advent of soft ionization procedures such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) have made it possible for compositional studies of the diverse lipid structures that are present in brain. These include phospholipids, ceramides, sphingomyelin, cerebrosides, cholesterol and their oxidized derivatives. Lipid analyses have delineated metabolic defects in disease conditions including mental retardation, Parkinson's Disease (PD), schizophrenia, Alzheimer's Disease (AD), depression, brain development, and ischemic stroke. In this review, we examine the structure of the major lipid classes in the brain, describe methods used for their characterization, and evaluate their role in neurological diseases. The potential utility of characterizing lipid markers in the brain, with specific emphasis on disease mechanisms, will be discussed. Additionally, we describe several proteomic strategies for characterizing lipid-metabolizing proteins in human cerebrospinal fluid (CSF). These proteins may be potential therapeutic targets since they transport lipids required for neuronal growth or convert lipids into molecules that control brain physiology. Combining lipidomics and proteomics will enhance existing knowledge of disease pathology and increase the likelihood of discovering specific markers and biochemical mechanisms of brain diseases.

Spontaneous rupture of spinal dermoid cyst with disseminated lipid droplets in central canal and ventricles

Free fat in the ventricular space is a rare but well recognized complication of ruptured tumour of dermal origin. However, only 1 patient of spontaneous rupture of spinal dermoid tumour with disseminated fat in the central canal and ventricles has been described in the literature. The authors report an extremely rare case of ruptured intraspinal dermoid and passage of free fatty droplets via the patent central canal to the intracranial CSF space. The detailed clinical presentation, radiological findings, and review of the literature are presented. Despite being rarely reported, spinal dermoid cyst can rupture spontaneously, and free fat disseminate into the ventricles, and in extremely rare cases, fat can enter into the central canal. It is underlinerd that a prompt detection, with the help of MRI is essential in cases of spinal dermoid tumour cyst, with sudden deterioration in neurological condition, keeping in mind, the possibility of free fat in the central canal.

[Diagnostics of traumatic fat embolism]

The article deals with diagnosis and treatment of fat embolism concomitant with trauma. A new term is suggested, i.e. liqoroglobulism, which is concomitant with the cerebral form of fat embolism. The results of investigations of patients, who endured fat embolism, are presented. A new method is suggested for the treatment of fat embolism, i.e. a combination of hemosorption and liquosorption. A thesis on that the blood-brain barrier is damaged in the cerebral form of fat embolism is formulated.

Stability of mRNA/cationic lipid lipoplexes in human and rat cerebrospinal fluid: methods and evidence for nonviral mRNA gene delivery to the central nervous system

Clinical applications of gene therapy require advances in gene delivery systems. Although numerous clinical trials are already underway, the ultimate success of gene therapies will depend on gene transfer vectors that facilitate the expression of a specific gene at therapeutic levels in the desired cell populations without eliciting cytotoxicity. In clinical applications for which transient expression is desirable, mRNA delivery is of particular interest. We have shown cationic lipid-mediated mRNA delivery to be feasible, efficient, and reproducible in vitro. mRNA delivery to the cerebrospinal fluid (CSF) in vivo would provide a means of vector distribution throughout the central nervous system (CNS). This study examined the functional integrity and protection from degradation of mRNA/cationic complexes (lipoplexes) in human cerebrospinal fluid (hCSF) in vitro and expression of these lipoplexes in vivo. Results obtained from gel electrophoresis indicate that cationic lipids protect mRNA transcripts from RNases in hCSF for at least 4 hr. This is in contrast to the total disappearance of nonlipid-complexed mRNA in less than 5 min. We confirmed the importance of RNase activity by incubating mRNA transcripts encoding luciferase or green fluorescent protein (GFP) in hCSF to which RNase inhibitors had been added. After incubation, these solutions were used to transfect Chinese hamster ovary (CHO) cells in vitro. Next, assays for both GFP and luciferase were used to demonstrate functional integrity and translation of the mRNA transcripts. Finally, we delivered in vitro transcribed mRNA vectors encoding for Hsp70 and luciferase to the lateral ventricle of the rat in a series of preliminary in vivo experiments. Initial immunohistochemistry analysis demonstrates that the distribution, uptake, and expression of reporter sequences using lipid-mediated mRNA vector delivery is extensive, as we earlier reported using similar methods with DNA vectors but that the expression may be less intense. Expression was noted in coronal sections throughout the rat brain, confirming the potential for lipid-mediated mRNA delivery to the CNS. These findings confirm that complexing mRNA with cationic lipid before exposure to CSF confers protection against RNase activity, facilitating distribution, cellular uptake, and expression of mRNA delivered into the CNS.

Resistance of human cerebrospinal fluid to in vitro oxidation is directly related to its amyloid-beta content

Amyloid-beta (A beta) peptide, a major constituent of senile plaques and a hallmark of Alzheimer's disease (AD), is normally secreted by neurons and can be found in low concentrations in cerebrospinal fluid (CSF) and plasma where it is associated with lipoproteins. However, the physiological role of A beta secretion remains unknown. We measured the resistance to in vitro oxidation of CSF obtained from 20 control subjects and 30 patients with AD, and correlated it with CSF levels of antioxidants, lipids and A beta. We found that the oxidative resistance, expressed as a duration of the oxidation lag-phase, was directly related to CSF levels of A beta 1-40, A beta 1-42 and ascorbate and inversely to levels of fatty acids. These data suggest that, besides ascorbate, A beta is another major physiological antioxidant for CSF lipoproteins.

Lipid-associated sialoprotein in the cerebrospinal fluid: association with brain malignancies

BACKGROUND

Changes in the glycosylation process by tumor cells result in larger amounts of sialoproteins on their surface compared with normal cells. Sialoproteins then are released into the surrounding environment primarily by shedding or cell lysis. In the current study, the authors attempted to evaluate whether lipid-associated sialoprotein (LSP) in the cerebrospinal fluid (CSF) can distinguish patients with primary and metastatic brain tumors from those without brain tumors as well as determine response to treatment.

METHODS

CSF samples were obtained from a tissue bank. The concentration of LSP was determined after chloroform:methanol extraction followed by protein precipitation. One-way analysis of variance and Scheffe pairwise comparisons were used for statistical analysis.

RESULTS

The CSF of neurologically normal controls, patients with a normal leukocyte count (< or = 5/microl), and patients with various neurologic disorders or systemic tumors without central nervous system (CNS) malignancies contained similar levels of LSP. The CSF from patients with a normal leukocyte count and newly diagnosed primary or metastatic brain tumors contained on average 3.7-fold higher levels of LSP compared with CSF from patients without CNS tumors (P = 0.0001). The CSF from patients with brain tumors with progressive disease not responding to treatment contained high levels of LSP comparable to the levels found in newly diagnosed patients. The CSF from treatment-responsive patients contained decreased levels of LSP similar to that found in control patients.

CONCLUSIONS

The LSP in CSF may be a useful marker with which to determine the presence of intracranial malignancies and assess response to treatment.

Rupture of spinal dermoid tumors with spread of fatty droplets in the cerebrospinal fluid pathways

Cranial and spinal MRI was carried out at 0.5 or 1.5 T in five patients with spinal dermoid tumours. Free fatty material was appreciated within the normally communicating cerebrospinal fluid pathways in all five cases and in one case fat droplets were also observed within a dilated central canal of the spinal cord. While dissemination of lipid within the subarachnoid space and ventricles is easily understandable, the presence of lipid droplets within the central canal is more difficult to explain, since the central canal is only potential in the adult. When a dermoid tumor is suspected, we recommend MRI of the entire central nervous system, to detect possible leakage of fat from rupture of a cystic portion of the tumour.

Time-course of oxidation of lipids in human cerebrospinal fluid in vitro

Oxidative mechanisms play an important role in the pathogenesis of Alzheimer's disease, Parkinson's disease and other neurodegenerative diseases. To assess whether the oxidation of brain lipoproteins plays a role in the development of these pathologies, we investigated whether the lipoproteins of human cerebrospinal fluid (CSF) are susceptible to oxidative modification in vitro. We studied oxidation time-course for up to 100 h of human CSF in the absence (autooxidation) or presence of exogenous oxidants. Autooxidation of diluted CSF was found to result in a slow accumulation of lipid peroxidation products. The time-course of lipid hydroperoxide accumulation revealed three consecutive phases, lag-phase, propagation phase and plateau phase. Qualitatively similar time-course has been typically found in human plasma and plasma lipoproteins. Autooxidation of CSF was accelerated by adding exogenous oxidants, delayed by adding antioxidants and completely inhibited by adding a chelator of transition metal ions. Autooxidation of CSF also resulted in the consumption of endogenous ascorbate, alpha-tocopherol, urate and linoleic and arachidonic acids. Taking into account that (i) lipid peroxidation products measured in our study are known to be derived from fatty acids, and (ii) lipophilic antioxidants and fatty acids present in CSF are likely to be located in CSF lipoproteins, we conclude that lipoproteins of human CSF are modified in vitro during its autooxidation. This autooxidation appears to be catalyzed by transition metal ions, such as Cu(II) and Fe(III), which are present in native CSF. These data suggest that the oxidation of CSF lipoproteins might occur in vivo and play a role in the pathogenesis of neurodegenerative diseases.

[Fibrinogen and lipids: associated risk factors for ischemic cerebral stroke]

The study included 55 patients (18 females, 37 males); aged 32-75 yr. who divided into three groups according to the severity of clinical picture: 12 people with reversible ischaemic stroke (RIS), 20 with progressive ischaemic stroke (PIS), 23 with complete stroke (CS). Levels of total cholesterol, high density lipoproteins (HDL), apolipoproteins A1 and B (ApoA1 and ApoB), fibrinogen (Fb) and Lp (a) were measured. Lipid factor of atherosclerosis (ATHi) was quantified. Qualitative evaluation of lipids contents in cerebrospinal fluid (CSR) was performed. Distribution of cholesterol--containing lipids among the fractions, despite low values, had clearly atherogenic profile. 12% patients with irreversible ischaemic stroke, 16% with progressive ischaemic stroke and 85% with complete stroke had Fb level above 4 g/l. Lp (a) levels in all cases were significantly higher in the cells isolated from CSF. The severity of the stroke correlated with increasing levels of lipids in the cells isolated from SF. There was correlation between LDL cholesterol and content of lipids in the cells from CSF.

Microsequencing of bovine cerebrospinal fluid apolipoproteins: identification of bovine apolipoprotein E

In studies of bovine plasma lipoproteins, apolipoprotein E (apoE) was not found associated with alpha-lipoproteins isolated over a broad range of densities. However, studies of cerebrospinal fluid (CSF) lipoproteins from other mammals have shown that apoE is a major apolipoprotein associated with high density lipoprotein, a fact that prompted us to determine if this were also the case in bovine CSF. CSF samples were obtained from animals with a surgically implanted catheter. Most analyzed samples were obtained from cows at various stages of the postpartum period; however, a few samples also were obtained at term or during pregnancy. Analyses of isolated ultracentrifugal fractions by polyacrylamide gel electrophoresis revealed the presence of two apo, with the expected molecular weights for apoE and apoA-I. By using both matrix-assisted laser desorption mass spectrometry and microsequencing techniques, we demonstrated that these apo are indeed apoE and apoA-I.

Chemical characterization of a family of brain lipids that induce sleep

A molecule isolated from the cerebrospinal fluid of sleep-deprived cats has been chemically characterized and identified as cis-9,10-octadecenoamide. Other fatty acid primary amides in addition to cis-9,10-octadecenoamide were identified as natural constituents of the cerebrospinal fluid of cat, rat, and human, indicating that these compounds compose a distinct family of brain lipids. Synthetic cis-9,10-octadecenoamide induced physiological sleep when injected into rats. Together, these results suggest that fatty acid primary amides may represent a previously unrecognized class of biological signaling molecules.

[Lipid peroxidation in the blood and spinal fluid of patients with craniocerebral injuries]

The content of the products of lipid peroxide oxidation in the plasma of blood flowing from the brain was higher in patients with moderate and severe craniocerebral injury than in patients with no marked functional and metabolic disorders. The concentration of these products in the cerebrospinal fluid was still higher. In patients with severe craniocerebral injury there was also an increase in the content of free fatty acids in blood flowing from the brain and in the content of ferrous iron ions in the cerebrospinal fluid. The intensification of the processes of lipid peroxide oxidation in the brain may play an essential role in determining the severity of the traumatic damage.

[Comparative studies on the lipid content of the cerebrospinal fluid and serum lipoprotein fractions in patients with discopathic changes]

The reported investigations were carried out in 12 subjects with low back pains caused by lumbar discopathy. The studied material were cerebrospinal fluid samples obtained during lumbar tap and blood obtained from the antecubital vein. In the fluid, serum and lipoprotein fractions the concentrations of cholesterol, triglycerides and phospholipids were determined. It was found that the concentration of the lipids determined in the cerebrospinal fluid in patients with discopathy was not different from that demonstrated in healthy subjects. The lipid content of the fluid differed significantly from that of the serum but was very similar to the composition of lipids in the high density lipoprotein fraction (HDL). The summed up concentration of cholesterol, triglycerides and phospholipids was about 170 times lower than that in the HDL fraction.

Thiobarbituric acid reactive substances and vitamin E in serum and cerebrospinal fluid from patients with cerebral apoplexy

Thiobarbituric acid (TBA) reactive substances in serum and cerebrospinal fluid from patients with cerebral apoplexy were determined and their relationship to this disease was studied. TBA reactants in serum were elevated in patients with cerebral apoplexy, but there was no difference between patients with brain tumor or other neurological disease and healthy persons. TBA reactants in cerebrospinal fluid in patients with cerebral aneurysm, cerebral arterial and venous anomalies or intracerebral hematoma, and its levels in patients with cerebral infarction or brain tumor were also higher than in healthy persons. Serum alpha-tocopherol levels were elevated in patients with cerebral infarction, but were relatively low in patients with cerebral aneurysm, cerebral arterial and venous anomalies or intracerebral hematoma. The reverse was the case with cerebrospinal fluid levels of alpha-tocopherol. That is, the sequence of decreasing level of alpha-tocopherol in cerebrospinal fluid was intracerebral hematoma, cerebral aneurysm, cerebral arterial and venous anomalies, and cerebral infarction. The levels of TBA reactive substances in patients with cerebral apoplexy showed a positive correlation between serum and cerebrospinal fluid, and the levels of alpha-tocopherol showed a similar correlation.

Hyperlipidaemia diagnosed at lumbar puncture

A patient presenting with subarachnoid haemorrhage and high lipid concentrations in the cerebrospinal fluid (taken at lumbar puncture), who has later shown to have type V hyperlipidaemia is described. This case, so far as can be ascertained by the authors, is the first report of hyperlipidaemia being diagnosed from CSF examination.

Use of the sulfo-phospo-vanillin reaction in a routine method for determining total lipids in human cerebrospinal fluid

Adult human cerebrospinal fluid (CSF) was assayed for total lipid levels by the sulfo-phospho-vanillin color reaction. Lipids in a 1-2 ml sample of CSF are extracted with a 2:1 chlofoform-methanol mixture and the solvent extract, after equilibration with 0.74 percent potassium chloride, is evaporated to dryness. The lipid in the residue is estimated by the sulfo-phospho-vanillin reaction. The extraction process is essentially quantitative for lipid mixtures normally found in CF. The technique has an average coefficient of variation of 1.5 percent and the recovery of added lipids is nearly quantitative. It can be used as a rapid routine method for estimating CSF total lipids and several samples can be processed simultaneously. Estimations of total lipid levels using the sulfo-phospho-vanillin reaction agree quite well with the results obtained by densitometric quantitation of charred lipids. A preliminary analysis of 22 samples of adult human CSF containing normal levels of total protein gave an average total lipid level of 0.78 (+/- 0.07 SEM) mg/dl. Total lipid levels in CSF did not significantly correlate with age. However lipid levels in CSF show a significant positive correlation with CSF total protein levels.

Floating Myodil--a new sign of fat in the ventricles

A case in which a remarkable series of CT studies demonstrated a dermoid cyst is reported. There was leakage of fat into the ventricular system which caused hydrocephalus due to adhesions partly obstructing the fourth ventricular outlets. The latter was confirmed by a ventriculogram using Myodil which dissolved in, or combined with, the fat produced by the tumour. This resulted in a high attenuation substance of lower specific gravity than CSF, which appeared to cause acute ventriculitis.

[The cerebro-spinal fluid: chemical values for diagnosis of meningitis (author's transl)]

We describe the chemical values of the normal cerebro-spinal fluid and any variation during meningitis. We also refere the physical peculiarity and the variations of non-proteins-nitrogen, of enzymes, of glucose and its metabolites, of proteins and cells. On the picture we resume the most significative variation for differential diagnosis among bacterial, viral and tuberculous meningitis.

Fatty change in the brain in perinatal and unexpected death

The presence of fat-laden cells in the cerebrospinal fluid is usually associated with a fatty change found particularly in the area of the tapetum in the postnatal infant. In a series of 307 child deaths the presence of fatty change in this area of the brain was age-related, decreased with age, and was rarely present over the age of 4 years. It was particularly common in stillborns and in children dying with respiratory distress, but was rare in children dying from acute surgical conditions or from acute infections. It was found in one-half of a series of 41 infants found unexpectedly dead and in whom no adequate cause of death was found. The most likely cause of this fatty change is thought to be chronic hypoxia.

The CSF lipid content in brain atrophy

Significantly low CSF values for cholesterol and total lipids were found in a group of patients with brain atrophy in comparison with a control group. It is possible that these changes are a function of reduced brain mass or of defect in brain lipid metabolism in brain atrophy patients. Further metabolic studies are required to clarify the biochemical aspects of brain atrophy.