Cerebrospinal fluid appearance

Body fluids other than urine have considerably less complex low-molecular-weight component spectrums, at least at the concentration levels that can be detected by these analyzers. For example, blood serum samples, when compared with urine, will have about one-fourth as many chromatographic peaks of UV-absorbing constituents and carbohydrates and about one-half as many ninhydrin-positive and organic acid chromatographic peaks. Cerebrospinal fluid appears to have about the same complexity in UV-absorbing and carbohydrate components as does blood serum, and perspiration falls somewhere between urine and serum. 

The histaminergic neurons have several well-developed primary and secondary dendrites that overlap with each other. Furthermore, long dendrites from histaminergic neurons located close to the mammillary recess or to the basal surface of the mammillary body appear to penetrate into the ependymal layer and make contact with cerebrospinal fluid. Thus, it is likely that neuroactive substances such as cytokines, present in the cerebrospinal fluid, may influence the discharge activity of TMN neurons (Wada et al., 1991). Unlike the dopaminergic neurons, which are known to release dopamine from their dendrites, there is no evidence that these histaminergic dendrites store and/or release HA. 

Table V contains data for two model substances, p-aminohippurate (PAH) and phenol red. Consideration of the highest values in this table tells you where the major portions of the substances appear. For example, urine and bile show the largest concentrations of PAH and phenol red. Both compounds appear in significant concentrations in the kidney while the values in muscle, brain and cerebrospinal fluid (CSF) are invariably lower than the values seen in plasma. The values in parentheses (Table V) are percent of the administered dose in a given tissue or fluid compartment. They add to the previous information by revealing the overall importance of a particular compartment in the disposition of a substance. For example, while the hepatic concentrations of PAH and phenol red at 4 hrs. are only about 2-fold those of plasma, the large size of the shark liver relative to its body weight, typically about 10%, leads to the appearance of 30-40% of these substances in the liver. The relative handling of these compounds by the urinary and biliary system is obvious from considering the percentage figures. Thus in 24 hours phenol red is about equally distributed in the bile and urine (38 vs 31%) the urinary route is the dominant route of excretion of PAH, i.e., 56 vs 2%.

The role of serotonin (5-hydroxytryptamine, 5-HT) has also been extensively studied in depressed patients. Whereas the overall psycho-physiological effects of noradrenaline in the CNS appear to be linked to drive and motivation, 5-HT is primarily involved in the expression of mood. It is not surprising therefore to find that the serotonergic system is abnormal in depression. This is indicated by a reduction in the main 5-HT metabolite, 5-hydroxy indole acetic acid (5-HIAA), in the cerebrospinal fluid of severely depressed patients and a reduction in 5-HT and 5-HIAA in the limbic regions of the brain of suicide victims. The 5-HT receptor function also appears to be abnormal in depression. This is indicated by an increase in the density of cortical 5-HT2a receptors in the brains of suicide victims and also on the platelet membrane of depressed patients. Platelets may be considered as accessible models of the nerve terminal. 

Borreliosis is a disease that frequently and typically affects both the central and peripheral nervous systems (Table 13 for a historical overview, see Table 14). Owing to the frequent occurrence in our area, it is possible to observe highly variable clinical manifestations as well as different types of pathological appearances in cerebrospinal fluid. Current methods used in neuroborreliosis diagnosis include the evaluation of specific antibodies IgM, IgG detected by ELISA, Western blot, and PCR. 

Reductions in renal and hepatic function do not alter plasma drug concentrations, and ketoconazole is not removed by hemodialysis or peritoneal dialysis. Penetration into cerebrospinal fluid is negligible, so that ketoconazole is ineffective in the treatment of fungal meningitis. Since only small amounts of active drug appear in the urine, ketoconazole is not effective in the treatment of Candida cystitis. 

Oxytocin, a nine amino acid peptide, is synthesized primarily in the paraventricular and supraoptic (SON) nuclei of the hypothalamus, from which it is released to the general circulation through the posterior pituitary (Insel et ah, 1997). However, oxytocinergic fibers have also been found to project from the PVN to the limbic system and several autonomic centers in the brain stem. This central OT pool appears to be independent of pituitary OT release cerebrospinal fluid (CSF) and plasma OT responses to numerous stimuli are not correlated (Insel, 1997). Oxytocin and its analog (or partner) peptide vasopressin are found only in mammals. A related peptide, vasotocin, thought to be the evolutionary precedent of these peptides, is found in reptiles and birds. The first known actions of OT were its peripheral effects on the physiology of new mothers. In mammals, OT stimulates milk ejection and uterine contraction, essential aspects of maternal physiology (Insel et ah, 1997). 

Fluman studies seem to support the animal data on the role of neurotrophic factors in stress states. Depression appears to be associated with a drop in BDNF levels in the cerebrospinal fluid and serum as well as with a decrease in tyrosine kinase receptor activity. Conversely, administration of antidepressants increases BDNF levels in clinical trials and may be associated with an increase in hippocampus volume in some patients. 

Saquinavir should be taken within 2 hours after a fatty meal for enhanced absorption. Saquinavir is 97% protein-bound, and serum half-life is approximately 2 hours. Saquinavir has a large volume of distribution, but penetration into the cerebrospinal fluid is negligible. Excretion is primarily in the feces. Reported adverse effects include gastrointestinal discomfort (nausea, diarrhea, abdominal discomfort, dyspepsia) and rhinitis. When administered in combination with low-dose ritonavir, there appears to be less dyslipidemia or gastrointestinal toxicity than with some of the other boosted PI regimens. 

Phenytoin is highly bound to plasma proteins. It appears certain that the total plasma level decreases when the percentage that is bound decreases, as in uremia or hypoalbuminemia, but correlation of free levels with clinical states remains uncertain. Drug concentration in cerebrospinal fluid is... 

The permanent positive charge of QTA influences distribution in vivo and prevents passage of blood-brain barrier and blood-cerebrospinal fluid barrier [30, 31]. Myolitic QTA are muscarinic receptor antagonists but allow a better therapeutic index as they are insoluble in lipids and thus poorly systemically absorbed (e.g. bioavailability of A-butyl-scopolamine after oral intake <1 % [30]). Therefore, spasmolytic activity in the GIT (by, e.g. cimetropium, butropium or /V-butyl-scopolamine, Fig. 1), respiratory tract (ipratropium, Fig. 1) and overactive bladder (trospium, Fig. 1) appears as the primary local effect whereas systemic side effects are markedly minimized or absent [32-34],... 

Biotinidase activity in cerebrospinal fluid and the brain is very low. This suggests that the brain may not recycle biotin effectively and depends on biotin transported across the blood-brain barrier. Several symptomatic children who have failed to exhibit peripheral lactic acidosis or organic aciduria have had elevated lactate or organic acids in their cerebrospinal fluid. This compartmentalization of the biochemical abnormalities may explain why the neurological symptoms usually appear before other symptoms. Peripheral metabolic ketoacidosis and organic aciduria subsequently occur with prolonged metabolic compromise. 

Virkkunen M, Nuutila A, Goodwin FK, Linnoila M. 1987b. Cerebrospinal fluid monoamine metabolite levels in male arsonists [published erratum appears in Arch Gen Psychiatry 1989 Oct 46(10) 960]. Arch Gen Psychiatry 44 241-247. 

SI 1. Souverijn, J. H., Peet, R., Smit, W. G., Serree, H. M., andBruyn, G. W., TheHAF enigma Origin and clinical consequences of the appearance of high alkaline fractions on isoelectric focusing patterns of cerebrospinal fluid. J. Neurol. Sci. 97(1), 117-128 (1990). 

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