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The central nervous system (CNS) is a known HIV reservoir, yet little is known about drug exposure in the brain. Our primary objective was to quantify exposure of three common antiretrovirals in brain tissue and compare exposures to plasma and cerebrospinal fluid (CSF). We also sought to identify pockets of brain most vulnerable to inadequate drug exposures and examine the role of meningitis in drug penetration into the CNS. Tenofovir, lamivudine, and efavirenz concentrations were measured using liquid chromatography and tandem mass spectrometry in plasma and CSF from 14 individuals with HIV, 7 with cryptococcal meningitis. In four individuals (three with meningitis) drug concentrations were also measured in 13 distinct brain tissue regions. In subjects with meningitis, geometric mean ratio (95% confidence interval) of tenofovir CSF to plasma was 66% (7-598%) and 14% (6-31%) in subjects without meningitis. Lamivudine CSF penetration was 100% (25-409%) in subjects with meningitis and 30% (24-37%) in subjects without meningitis. Tenofovir brain tissue concentrations were 36% (14-124%) of plasma and 49% (1-572%) of CSF. Lamivudine brain concentrations were 37% (23-64%) of plasma and 27% (1-104%) of CSF. Efavirenz brain tissue concentrations were 128% (108-179%) of plasma. Tissues collected postmortem provide a unique opportunity to assess drug distribution in tissues difficult to sample in living subjects. CSF is a poor surrogate for drug exposure throughout the CNS. Antiretrovirals differentially penetrate into the CNS and penetration may be enhanced by meningitis., (© 2019 The Authors. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

The lack of a single predictive or diagnostic test in multiple sclerosis (MS) remains a major obstacle in the patient's care. The aim of this study was to investigate metabolic profiles, especially lipids in cerebrospinal fluid (CSF) using 1 H-NMR spectroscopy and metabolomics analysis to discriminate MS patient group from the control ones. In this study, 19 MS patients and 19 controls, without neurological problems, patients were enrolled. To obtain the CSF metabolic profiles, NMR spectroscopy was used. Hydrophilic and hydrophobic compounds were analyzed using univariate and multivariate supervised analysis orthogonal partial least square discriminant analysis (OPLS-DA). Targeted OPLS-DA analysis of 32 hydrophilic and 17 hydrophobic compounds obtained 9 hydrophilic metabolites and 8 lipid functional groups which had the highest contribution to patient's group separation. Lower concentrations of CSF hydrophilic and hydrophobic compounds were observed in MS patients as compared to control group. Acetone, choline, urea, 1,3-dimethylurate, creatinine, isoleucine, myo-inositol, leucine, and 3-OH butyrate; saturated and monounsaturated acyl groups of ω-9, ω-7, ω-6, ω-3, and fatty acid, triglycerides, 1,3-DG, 1-MG, and unassigned component signal at 3.33 ppm were the most important signal compounds in group separation. Analysis of metabolic profile of raw CSF and their lipid extract shows decreased levels of many compounds and led to the conclusion that MS patients could have a disturbance in many metabolic pathways perhaps leading to the decreased level of acetyl-CoA and/or inflammation. CSF metabolic profile analyses could be used as a fingerprint for early MS diagnosis.

The diagnosis of drowning is still a difficult task in forensic science. Biochemical changes in different body fluids have been examined for the identification of drowning. However, none of them alone gives accurate results in the diagnosis of drowning and differentiation of saltwater and freshwater drowning. This study aimed to examine cerebrospinal fluid changes in drowned rabbits. Six groups of rabbits were used including immersed dead rabbits in freshwater or saltwater (as control groups), alive fully conscious rabbits drowned in freshwater and saltwater, and anesthetized rabbits drowned in freshwater and saltwater. Cerebrospinal fluid electrolytes except for potassium levels were significantly higher in rabbits drowned consciously in saltwater than their level in the control group. In rabbit drowned in freshwater, the examined electrolytes decreased significantly. In addition, urea, creatinine, uric acid, glucose, and tumor necrosis factor were different in cases of freshwater and saltwater drowning from those of control rabbits. Electrolytes and biochemical changes of unconscious rabbits drowned in water showed no significant difference from those of control rabbits. Cerebrospinal fluid examination in drowning gives promising results in the diagnosis of drowning. In addition, the differentiation between freshwater and saltwater drowning was possible.

Background: We explored the establishment of abnormal blood-brain barrier (BBB) permeability and its relationship to neuropathogenesis during primary human immunodeficiency virus (HIV) infection by evaluating the cerebrospinal fluid (CSF) to serum albumin quotient (QAlb) in patients with primary HIV infection. We also analyzed effects of initiating combination antiretroviral therapy (cART)., Methods: The QAlb was measured in longitudinal observational studies of primary HIV infection. We analyzed trajectories of the QAlb before and after cART initiation, using mixed-effects models, and associations between the QAlb and the CSF level of neurofilament light chain (NFL), the ratio of N-acetylaspartate to creatinine levels (a magnetic resonance spectroscopy neuronal integrity biomarker), and neuropsychological performance., Results: The baseline age-adjusted QAlb was elevated in 106 patients with primary HIV infection (median time of measurement, 91 days after infection), compared with that in 64 controls (P = .02). Before cART initiation, the QAlb increased over time in 84 participants with a normal baseline QAlb (P = .006) and decreased in 22 with a high baseline QAlb (P = .011). The QAlb did not change after a median cART duration of 398 days, initiated at a median interval of 225 days after infection (P = .174). The QAlb correlated with the NFL level at baseline (r = 0.497 and P < .001) and longitudinally (r = 0.555 and P < .001) and with the ratio of N-acetylaspartate to creatinine levels in parietal gray matter (r = -0.352 and P < .001 at baseline and r = -0.387 and P = .008 longitudinally) but not with neuropsychological performance., Conclusion: The QAlb rises during primary HIV infection, associates with neuronal injury, and does not significantly improve over a year of treatment. BBB-associated neuropathogenesis in HIV-infected patients may initiate during primary infection., (© The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Creatinine is the most important parameter to be determined in the diagnosis of renal, muscular and thyroid function. The most common method for the determination of creatinine is Jaffe's reaction, a routine practice for blood and urine analysis. However, in cases of icteric and haemolyzed blood samples, interference occurs during the estimation of creatinine by other constituents present in the blood like bilirubin, creatine, and urea, which lead to wrong diagnosis. To overcome such difficulty, we have developed a silver nanoparticle (Ag NPs) based sensor for the selective determination of creatinine. In this study, a new approach has been given to the traditional Jaffe's reaction, by coating Ag NPs with picric acid (PA) to form an assembly that can selectively detect creatinine. The Ag NPs based sensor proficiently and selectively recognizes creatinine due to the ability of picric acid to bind with it and form a complex. The nanoassembly and the interactions were investigated by transmission electron microscopy (TEM), dynamic light scattering (DLS) analysis, UV-Vis spectroscopy, FT-IR spectroscopy and ESI-MS, which demonstrated the binding affinity of creatinine with PA-capped Ag NPs. A linear correlation was obtained in the range of 0.01 μM-1 μM with an R(2) value of 0.9998 and a lower detection limit of 8.4 nM. The sensor was successfully applied to different types of blood and CSF samples for the determination of creatinine, and the results were compared to that of the Jaffe's method. With the advantages of high sensitivity, selectivity and low sample volume, this method is potentially suitable for the on-site monitoring of creatinine.

Plasma, urine and cerebrospinal fluid (CSF) were examined for biochemical markers of dementia. Protein-conjugated acrolein (PC-Acro) and the amyloid-β (Aβ)40/42 ratio in plasma can be used to detect mild cognitive impairment (MCI) and Alzheimer's disease (AD). In plasma, PC-Acro and the Aβ40/42 ratio in MCI and AD were significantly higher relative to non-demented subjects. Furthermore, urine acrolein metabolite, 3-hydroxypropyl mercapturic acid (3-HPMA)/creatinine (Cre) and amino acid-conjugated acrolein (AC-Acro)/Cre in AD were significantly lower than MCI. It was also shown that reduced urine 3-HPMA/Cre correlated with increased plasma Aβ40/42 ratio in dementia. The Aβ40/PC-Acro ratio in CSF, together with Aβ40 and Aβ40/42 ratio, was lower in AD than MCI. Increased plasma PC-Acro and Aβ40/42 ratio and decreased urine 3-HPMA/Cre correlated with cognitive ability (MMSE). These results indicate that the measurements of acrolein derivatives together with Aβ and Cre in biologic fluids is useful to estimate severity of dementia., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Biochemical detection of inborn errors of creatine metabolism or transport relies on the analysis of three main metabolites in biological fluids: guanidinoacetate (GAA), creatine (CT) and creatinine (CTN). Unspecific clinical presentation of the diseases might be the cause that only few patients have been diagnosed so far. We describe a LC-MS/MS method allowing fast and reliable diagnosis by simultaneous quantification of GAA, CT and CTN in urine, plasma and cerebrospinal fluid (CSF) and established reference values for each material. For quantification deuterated stable isotopes of each analyte were used as internal standards. GAA, CT and CTN were separated by reversed-phase HPLC. The characterization was carried out by scanning the ions of each compound by negative ion tandem mass spectrometry. Butylation is needed to achieve sufficient signal intensity for GAA and CT but it is not useful for analyzing CTN. The assay is linear in a broad range of analyte concentrations usually found in urine, plasma and CSF. Comparison of the "traditional" cation-exchange chromatography and LC-MS/MS showed proportional differences but linear relationships between the two methods. The described method is characterized by high speed and linearity over large concentration ranges comparable to other published LC-MS methods but with higher sensitivity for GAA and CT. In addition, we present the largest reference group ever published for guanidino compounds in all relevant body fluids. Therefore this method is applicable for high-throughput approaches for diagnosis and follow-up of inborn errors of creatine metabolism and transport., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Several studies indicate that changes in cerebrospinal fluid (CSF) composition depend on the disease stage and reflect modification of brain energy metabolism (BEM). Also, it has been reported that a decline in cognitive functions may be mitigated by incorporating nutraceuticals in the diet., Objective: Assuming the beneficial effect of nutraceuticals on BEM and oxidative damage, the aim of this study was to determine if the administration of a nutraceutical compound results in changes of select CSF biomarkers in healthy adult Beagle dogs., Methods: Two separate CSF and blood samples were obtained from 11 healthy adult Beagle dogs, before and after 50 days of treatment with a veterinary combined nutraceutical. CSF analysis included a total nucleated cell count, total protein, glucose, sodium, chloride, potassium, pyruvate, and lactate concentrations, and calculation of lactate/pyruvate ratio. CBC and serum biochemistry were also performed. The Wilcoxon test was used to analyze the significance of the changes after nutraceutical treatment., Results: All studied variables remained within reference intervals, before and after treatment. A significant increase in CSF sodium and glucose concentration, and a decrease in lactate levels, was observed after treatment (P < .05), and the lactate/pyruvate ratio was decreased after treatment (P = .05). In serum, sodium and chloride concentrations were significantly increased (P < .05), and creatinine concentration was significantly decreased (P < .05) after treatment., Conclusions: After 50 days of treatment with a nutraceutical compound, CSF glucose, sodium, and lactate concentrations, and L/P ratio were significantly different, suggesting an influence of nutraceuticals' administration on CSF composition., (©2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.)

Guanidinoacetate (GAA) and creatine (Cr) are creatine deficiency syndromes (CDS) biochemical markers. We describe a liquid chromatography - tandem mass spectrometry method (LC/MSMS) performing simultaneous analysis of GAA, Cr and creatinine (Crn). Study of Cr uptake by fibroblasts for Cr transporter defect diagnosis is also assessed. The three butylated compounds were separated by liquid chromatography and MSMS quantification was achieved by isotopic dilution with electrospray positive ion mode. Linearity was demonstrated from 0 to 600, 675 and 4500 μmol/L and limit of quantification was 0.1, 0.04 and 0.9 μmol/L for GAA, Cr, and Crn respectively. Intra- and inter-assay precision for each analyte was better than 11%, and standard recoveries ranged from 83 to 109%. Reference values in cerebrospinal fluid samples for subjects ≥14 years were also established for GAA and Cr. Five fibroblast cell lines were used for Cr uptake study. Cr uptake by fibroblasts increased with the Cr media concentrations and was significantly inhibited by 3-guanidinopropionate (500 μmol/L), a Cr transporter inhibitor (96h incubation, [Cr media] = 25 μmol/L, p<0.05). A reliable LC/MSMS method for the diagnosis of CDS was developed in different biological fluids. Finally, results of the Cr uptake study reinforce the interest of this technique to diagnose Cr transporter deficiencies.

Neurobiological markers in cerebrospinal fluid (CSF) and in serum, previously found to co-vary with destructive personality traits in violent offenders, were explored in a general population sample of 21 patients undergoing knee surgery. Results on the Karolinska Scales of Personality (KSP) and the Temperament and Character Inventory (TCI) were compared with CSF/serum albumin ratios and serum concentrations of beta-trace protein (betaTP) (as markers for blood-brain barrier (BBB) permeability), to CSF/serum albumin ratios between the dopamine and serotonin metabolites homovanillic acid (HVA)/5-hydroxyindoleacetic acid (HIAA) and to CSF and serum ratios between activated thyroid hormone (T3) and its precursor T4. Serum betaTP concentrations correlated with CSF/serum albumin ratios (P=0.018), but not with preoperative serum creatinine concentrations. Serum betaTP correlated significantly with Monotony Avoidance and Impulsiveness; CSF HVA/5-HIAA ratios with Irritability and low Cooperativeness. The betaTP is a potential serum marker for the integrity of the BBB that does not necessitate lumbar puncture. Thyroid hormones did not correlate with personality traits. As reported in forensic psychiatric patients, aggressive, unempathic personality traits were thus associated with increased dopaminergic activity in relation to the serotonergic activity and impulsivity to increased BBB permeability also in a general population group., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

Background: By using surface enhanced laser desorption/ionisation- time of flight mass spectrometry (SELDI-TOF MS) an amyloid beta (Abeta) profile was shown in cerebrospinal fluid (CSF) of patients with dementia., Objective: To investigate the Abeta-profile in serum with SELDI-TOF MS, to evaluate if this profile resembles CSF profiles and to investigate the correlation between intensity of Abeta-peptide-peaks in serum and clinical, demographical and genetic variables., Methods: Duplicate profiling of Abeta by an SELDI-TOF MS immunocapture assay was performed in 106 patients, suffering from Alzheimer's Disease or Vascular Dementia and age-matched non-demented control patients. Linear regression analyses were performed to investigate the intensities of four selected Abeta peaks as dependent variables in relation to the independent clinical, demographic or genetic variables., Results: Abeta37, Abeta38 and Abeta40 were found among additional unidentified Abeta peptides, with the most pronounced Abeta peak at a molecular mass of 7752. This profile partly resembled the CSF profile. The clinical diagnosis was not a predictive independent variable, however ABCB1 genotypes C1236T, G2677T/A, age and creatinine level showed to be related to Abeta peak intensities in multivariate analyses., Conclusions: We found an Abeta profile in serum that partly resembled the CSF profile in demented patients. Age, creatinine levels, presence of the APOE epsilon4 allele and ABCB1 genotypes (C1236T and G2677T/A) were correlated with the Abeta serum profile. The role of P-gp as an Abeta transporter and the role of ABCB1 genotypes deserves further research. The investigated serum Abeta profile is probably not useful in the diagnosis of dementia.

Unlabelled: Postmortem phenomena can change and alter biochemical components in body fluids such as blood and as cerebrospinal fluid (CSF). AIMS OF THE STUDY WERE: (a) to analyse urea, glucose, potassium, chloride, protein, creatinine, calcium, alkaline phosphatase and cortisol in CSF fluid and (b) to compare results between two age groups, between groups with or without mental or degenerative neurological illness and between a group reported as dying from natural causes and a group that had a violent death., Materials and Methods: The study was carried out in Hospitalet de Llobregat (Barcelona) of 55 corpses. Samples were obtained following section of the corpus callosus, through the lateral ventricles and frozen to -80 degrees C until processed., Results: Significant differences were found in urea levels between the two age groups, in protein between natural and violent death groups and in alkaline phosphatase between the two age groups and between the natural and violent death group. Cortisol levels revealed significant difference between the two age groups and is those supplying natural and violent death., Conclusions: The study indicates to the need for further studies designed to include groups with defined diagnose of mental or degenerative disorders as well as different age groups.

Metabolite levels in cerebrospinal fluid from patients with lower back pain and/or sciatica caused by disc herniation or spinal stenosis were compared with levels in pain-free controls using proton magnetic resonance spectroscopy. Significant differences for several metabolites were found in patients with pain compared with controls. Most changes were found in the group with disc herniation, including reductions in glucose, alanine, and lactate, suggesting increased aerobic metabolism in this group. There was a significant reduction in the level of glucose in the group with spinal stenosis irrespective of whether the patients were compared with the whole control group (age-weighted) or with age-matched controls. Additionally, inositol and creatinine were reduced in patients with disc herniation. Inositol was also significantly reduced in the spinal stenosis group when age matched to controls. Insofar as the levels of pain recorded by the patients with lumbar pathology were similar in the two groups, it seems more likely that the reductions in metabolite levels recorded in the group with disc herniations are related to disc pathology rather than the perception of pain. However, the possibility that pain perception contributes to the metabolic changes cannot be excluded., (Copyright 2002 Wiley-Liss, Inc.)

The purpose of the study was to investigate the sequence of processes occurring during and after hypoxia-induced acidemia. We used proton nuclear magnetic resonance spectroscopy, which provides an overview of metabolites in cerebrospinal fluid (CSF), reflecting neuronal metabolism and damage. The pathophysiological condition of acute fetal asphyxia was mimicked by reducing maternal uterine blood flow in 14 unanesthetized pregnant ewes. CSF metabolites were measured during hypoxia-induced acidemia, and during the following recovery period, including the periods at 24 and 48 h after the hypoxic insult. Maximum values of the following CSF metabolites were reached during severe hypoxia (pH

Hepatic guanidinoacetate methyltransferase deficiency induces a deficiency of creatine/phosphocreatine in muscle and brain and an accumulation of guanidinoacetic acid (GAA), the precursor of creatine. We describe a patient with this defect, a 4-year-old girl with a dystonic-dyskinetic syndrome in addition to developmental delay and therapy-resistant epilepsy. Several methods were used in the diagnosis of the disease: (1) the creatinine excretion in 24-hour urine was significantly lowered, whereas the creatinine concentration in plasma and in randomly collected urine was not strikingly different from control values; (2) the Sakaguchi staining reaction of guanidino compounds in random urine samples indicated an enhanced GAA excretion; (3) GAA excretion measured quantitatively by guanidino compound analysis using an amino acid analyzer was markedly elevated in random urine samples; (4) in vivo 1H magnetic resonance spectroscopy (MRS) revealed a strong depletion of creatine and an accumulation of GAA in brain; (5) in vivo phosphorus 31 MRS showed a strong decrease of the phosphocreatine resonance and a resonance identified as guanidinoacetate phosphate; and (6) in vitro 1H MRS showed an absence of creatine and creatinine resonances in cerebrospinal fluid and the occurrence of GAA in urine. For early detection of this disease, we recommend the Sakaguchi staining reaction of urine from patients with dystonic-dyskinetic syndrome, seizures, and psychomotor retardation. Positive results should result in further investigations including quantitative guanidino compound analysis and both in vivo and in vitro MRS. Although epilepsy was not affected by orally administered creatine (400 to 500 mg/kg per day), this treatment resulted in clinical improvement and an increase of creatine in cerebrospinal fluid and brain tissue.

Cerebrospinal fluid (CSF) collected at the atlanto-occipital site and serum were obtained from 10 male, 8-week-old, Holstein calves after sedation with xylazine hydrochloride. Glucose, creatine kinase, alkaline phosphatase, urea nitrogen, creatinine, sodium, potassium, chloride, calcium, phosphorus, total protein, and albumin were determined in serum and CSF. Optical characteristics, specific gravity, total red blood cell and nucleated cell counts and differentials were also evaluated in the CSF. Additionally, CSF protein electrophoresis and immunoglobulin concentrations were determined. Then, albumin quotients (AQ) were derived. Erythrocytes were observed in 9 of 10 CSF samples. Total nucleated cell counts ranged from 0-10 cells x 10(6)/L with a mean of 3 cells x 10(6)/L. Differential nucleated cell count in the CSF consisted primarily of lymphocytes/small mononuclear cells (57%), fewer monocytes/ large mononuclear cells (38%), and scant neutrophils (4%) and eosinophils (0.05%). The concentration of sodium (134 to 139 mEq/L) was similar to that of serum, but the concentration of potassium (2.8 to 3 mEq/L) was lower than that of serum. Creatine kinase activity (0 to 4 U/L) of CSF was markedly lower than serum activity. The CSF glucose concentration was approximately 80% of the serum value. Cerebrospinal fluid total protein concentration determined by electrophoresis ranged from 110 to 330 mg/L with a mean of 159 mg/L. Cerebrospinal fluid albumin ranged from 48 to 209 mg/L with a mean of 86 mg/L. In all CSF samples, radial immunodiffusion of unaltered CSF and concentrated CSF (four-fold concentration) revealed quantities undetectable by the present techniques in which the lowest standard values for IgG1, IgG, and IgM determinations was 70 mg/L and IgG2 was 30 mg/L. The albumin quotient ranged from 0.15 to 0.65 with a mean of 0.25. Based on the results of this study, CSF may be collected at the atlanto-occipital site safely and efficiently in calves, and reported values for CSF from adult cattle may not be suitable for evaluation of CSF collected from immature cattle.

The purine metabolites hypoxanthine, xanthine and urate as well as creatinine were measured in cerebrospinal fluid (CSF) from two groups of patients and a reference sample group. In one of the patient groups lumbar CSF was collected in 2 ml portions until a total volume of 14 ml was withdrawn. Every second portion was analysed for its content of the metabolites in focus. In the other patient group both cisternal CSF and a fixed volume (20 ml) of lumbar CSF were obtained and analysed. An increase in concentration of hypoxanthine, xanthine and creatinine and a decrease in urate concentration was found in the successive CSF specimens. The mean individual increase in hypoxanthine concentration between the first and the last 2 ml portion was as high as 39.6%, while it was lower for xanthine, 21.5%, and creatinine, 6.7%. The decrease in urate concentration was 17.2%. The results from the other patient group were in good agreement with these findings. The concentrations in the cisternal CSF was 162% of that in lumbar CSF for hypoxanthine, 155% for xanthine, 123% for creatinine and 80% for urate. Mechanisms behind inter- and intraindividual differences in gradients are discussed.

Parathyroid hormone is reported to be a possible causal factor of abnormalities of electroencephalograms of patients with renal failure. In this study, the parathyroid hormone levels were compared in the circulation and cerebrospinal fluid of seven normal subjects and 22 patients with renal failure including those who showed abnormal electroencephalograms. The circulating levels of both C-terminal and N-terminal parathyroid hormone in the subjects studied showed a positive correlation (C-terminal, r = 0.58, P less than 0.01; N-terminal, r = 0.61, P less than 0.01) with the grade of abnormality of the electroencephalogram. However, the levels of C-terminal and N-terminal parathyroid hormone in the cerebrospinal fluid of both normal subjects and patients with renal failure were below the detectable limit (C-terminal, less than 0.1 ng/ml; N-terminal, less than 2.3 pg/ml). These data suggest that in patients with renal failure, the effect of parathyroid hormone on the central nervous system is mediated in some other way than via the cerebrospinal fluid.

A prospective high performance liquid chromatography (HPLC) study was performed in eighteen patients with head injury and stroke and four control volunteers to evaluate creatinine and purine metabolites concentration (adenosine, inosine, hypoxanthine, uric acid) in cerebrospinal fluid (CSF). The present HPLC method is rapid, accurate and sensitive in the same isocratic run and no specimen pretreatment of 0.02 ml CSF is necessary. The creatinine level in CSF was increased from 122 to 169 mumol/l in some patients, and was found unrelated to that of serum. The uric acid levels varied between 5.8 and 121 mumol/l and were associated with decrease in Glasgow Coma Scale score and had a critical point of 30 mumol/l. We present initial results in application of HPLC method to measure the creatinine and purine metabolites in CSF. This preliminary report presents that these high levels in CSF of head injury and stroke patients probably reflect tissue damage and an increased tissue catabolism.

Time and temperature effects on postmortem cerebrospinal fluid samples from 60 adult mongrel dogs were studied. After death the dogs were held at 4, 20, or 37 degrees C for intervals of 3, 6, 12, 24, or 48 h. Antemortem and postmortem cerebrospinal fluid was evaluated for sodium, chloride, potassium, urea nitrogen, glucose, creatinine, calcium, phosphorus, and carbon dioxide. Sodium and urea nitrogen values remained stable. Chloride may be of forensic science value. Low levels of postmortem calcium might indicate antemortem hypocalcemia; high levels of postmortem glucose may indicate antemortem hyperglycemia. Calcium and creatinine levels increased slightly but continually after death; carbon dioxide values dropped.

Concentrations of creatinine in cerebrospinal fluid (CSF) from schizophrenic patients and healthy control subjects were determined by a liquid chromatographic method. The concentration of creatinine in CSF from schizophrenic patients was lower (42.8 nmol/ml) than that of the controls (54.4 nmol/ml). The concentration of creatinine was correlated to the levels of homovanillic acid and 5-hydroxyindoleacetic acid. Treatment of the schizophrenic patients with sulpiride (800 mg daily), but not with chlorpromazine, elevated the concentration of creatinine in the CSF.

An easy method for collecting cerebrospinal fluid (CSF) was developed using a catheter inserted into the cisterna magna of rabbits. Levels of guanidino compounds in CSF collected by this method were measured. Levels of guanidinoacetic acid and creatinine increased at the onset of a pentylenetetrazol (PTZ)-induced convulsion. These levels normalized 2 h after the convulsion. The arginine level started to decrease 2 h after the convulsion, continued to decrease gradually and normalized 4 days after the convulsion. These results suggest that guanidinoacetic acid and creatinine are related to the initiation of PTZ-induced convulsions, and that 4 days are required for the metabolism of guanidino compounds to return to normal after a convulsion in rabbits.

Concentrations of hypoxanthine, xanthine, uric acid and creatinine were measured in CSF of patients suffering form presenile and senile dementia of Alzheimer type (PDAT, SDAT) and multi infarct dementia (MID) and in a reference group of young neurotic patients. There was no difference in hypoxanthine concentration, but there was a marked elevation of xanthine concentration in each dementia group, independent of the type of dementia. There was a significant elevation of uric acid in SDAT and MID but not in PDAT. The concentration of uric acid was higher in MID than in SDAT. There was a higher level of creatinine in the dementia groups, but no difference was seen among the dementia groups. These results are discussed in order to better interpret the etiology and the differentiated diagnosis of the types of dementia.

In this method for simultaneously determining hypoxanthine, xanthine, urate, and creatinine in cerebrospinal fluid, centrifuged sample is directly injected on a reversed-phase liquid-chromatographic column. On elution with potassium phosphate buffer the compounds are quantified by their absorbance at 260 nm. Random error (CV) was between 1.2 and 3.4% and analytical recoveries were 99-104% at physiological concentrations.

In an attempt to chemically estimate cerebral energy metabolism, creatine and creatinine was measured in cerebrospinal fluid and plasma of up to 135 patients with RDC diagnoses of major depressive disorders. A strong positive age effect and a significant subdiagnostic difference were detected for both substances in CSF, but not in plasma. Primary unipolar patients had higher concentrations than either secondary unipolar or bipolar patients. Further, the two CSF measures correlated highly significantly and positively with the CSF monoamine metabolites HVA and 5-HIAA and the purine metabolites hypoxanthine and xanthine. Results indicate alterations in energy metabolism to be involved in affective disorders as well as in the regulation of monoamine and purine turnover.

An improved and direct analysis of endogenous creatinine levels using the reversed-phase mode of high performance liquid chromatography (RPLC) is described. The analysis is rapid, the sensitivity of the spectrophotometric detection is in the nanomole range, and the sample preparation requires only filtration to remove the particulate matter. Identification of chromatographic peaks was achieved by means of absorbance ratios, stopped-flow UV spectra and prechromatographic incubation of samples with creatinine amidohydrolase. Reported in this paper are representative chromatograms of samples of amniotic fluid, urine, and cerebrospinal fluid (CSF). The ranges of creatinine concentrations in 10 samples of amniotic fluid, urine and CSF were 0.774--1.850, 99--454.5 and 0.648--1.05 mg/100 ml, respectively. This highly specific and simple assay offers several improvements over previously used methods.

Brains of methoxyflurane-anesthetized chickens were perfused from a lateral cerebral ventricle to cisterna magna with an artificial cerebrospinal fluid (CSF) containing trace quantities of radioiodinated human serum albumin (RIHSA) or inulin (1.0 mg/ml) to measure CSF bulk absorption. In addition, it contained either trace quantities of 22Na, 42K, 45Ca or [14C]creatinine; the concentrations of the latter three were varied to determine permeability coefficients (K-D's) as a function of concentration. A mass balance for the tracer molecules was calculated to determine their movement into brain or blood. K-D's for 45Ca, 42K, 22Na, and creatinine (Cr) were unaffected by perfusion time and the latter two were larger than previously reported (3). The lack of effect of time on K-D and the large values for K-D22Na and K-D-Cr are attributed to anesthetic effects on brain blood flow. K-D-Cr and K-D42K were larger than K-D22Na or K-D45Ca and K-D's for 45Ca, Cr, and 42K were independent of their inflow concentrations. An active transport process is suggested for potassium and creatinine, but one that is located at sites other than the ependymal wall. Bulk flow clearance accounted for RIHSA movement from CSF, whereas nonbulk clearance accounted for 50% of 22Na and 45Ca movement and 90% of 42K clearance. Fifty percent of 42K and 25% of 22Na and 45Ca were found in brain. The large recovery of 42K in brain supports the hypothesis that intracellular potassium serves as an exchangeable pool for the tracer.

The brain ventricular system of the adult dog was perfused with an artificial cerebrospinal fluid (CSF) containing inulin, creatinine and radioactively labeled p-aminohippuric acid (PAH) and mannitol. Inflow and outflow rates and concentrations of test molecules were measured at different intraventricular pressures, allowing calculation of their steady-state rates of removal from the ventricles. Clearance of inulin, a measure of CSF bulk absorption varied nearly with intraventricular pressure (- 15 to +12 cm H2O relative to the external auditory meatus). The efflux coefficient (Ko; representing clearance of a molecule by means other than bulk absorption) for mannitol was independent of intraventricular pressure. Ko's for PAH and creatinine were pressure dependent. PAH and creatinine efflux may be related to the amount of fourth ventricular choroid plexus surface exposed to the perfusion fluid. Ko's for creatinine and PAH (46 plus or minus 4 mul/min; 34 plus or minus 4mul/min, respectively) were significantly greater than mannitol (16 plus or minus 8 mul/min) at comparable intraventricular pressures, suggesting that both creatinine and PAH leave the CSF by an active process in addition to passive diffusion.