This study is concerned with the mechanism of exchange of sodium between plasma and cerebrospinal fluid (CSF). Several workers (1, 2) have reported that there is no significant difference between the concentration of sodium in plasma and CSF. Merritt and Fremont-Smith (3) reported that the average concentration of sodium in CSF, in man, exceeded the plasma concentration by about four mEq. Davso...

Radiological Sciences, King’s College, London, U.K. Departments of Radiology and Surgery, University of Minnesota, U.S.A. Philips Medical Systems, Best, the Netherlands. The shape of the brain and the position of anatomical structures can change during neurosurgical procedures. Such changes can be due to to differences between the patient’s position in acquisition and during surgery, reduction ...

Chuckwalla lizards (genus Sauromalus) may accumulate substantial quantities of body fluid in extracoelomic, lateral abdominal spaces called accessory lymph sacs. The lymph sac fluid (LSF) of S. hispidus is similar to that of serum in Na+, K+ and Cl- concentrations, but the total protein content (3.58 +/- 0.20 g dl-1) is only half that measured in serum (7.05 +/- 0.26 g dl-1). These analyses con...

Fluid shifts are commonplace in chronic hemodialysis patients during the intra- and interdialytic periods. In this study, we evaluated fluid shifts of body compartments using both bioimpedance spectroscopy and blood volume monitoring from the start to the end of hemodialysis. 24 stable hemodialysis patients were included on the study. Relative change of blood volume was progressively reduced fr...

There are at least two problems in estimating the volume of a body fluid compartment. First, a substance must be found which is distributed in the volume to be measured, and second, a method must be made available which will measure the distribution of the substance. In the literature, substance and method are rarely, if ever, separated. Kruhoffer (1), for example, states that an ideal indicato...

There are at least two problems in estimating the volume of a body fluid compartment. First, a substance must be found which is distributed in the volume to be measured, and second, a method must be made available which will measure the distribution of the substance. In the literature, substance and method are rarely, if ever, separated. Kruhoffer (1), for example, states that an ideal indicato...

BACKGROUND We have compared the pharmacokinetics and brain distribution of lidocaine, racemic bupivacaine (bupivacaine), and levobupivacaine in awake, spontaneously breathing rats. METHODS Lidocaine (0.5 mg x kg x min), bupivacaine (0.1 mg x kg x min), or levobupivacaine (0.1 mg x kg x min) was continuously administered to rats for 2 h (n = 12, each anesthetic). Blood samples and cerebral dia...

Hydrogen peroxide (H(2)O(2)) scavenging systems of spruce (Picea abies) needles were investigated in both extracts obtained from the extracellular space and extracts of total needles. As assessed by the lack of activity of symplastic marker enzymes, the extracellular washing fluid was free from intracellular contaminations. In the extracellular washing fluid ascorbate, glutathione, cysteine, an...

Traumatic brain injury causes diffuse axonal injury and loss of cortical neurons. These features are well recognized histologically, but their in vivo monitoring remains challenging. In vivo cortical microdialysis samples the extracellular fluid adjacent to neurons and axons. Here, we describe a novel neuronal proteolytic pathway and demonstrate the exclusive neuro-axonal expression of Pavlov's...

Salt has been used as a food preservative and part of the human diet for thousands of years. Consequently, human dietary sodium chloride intake is significantly higher than that needed to sustain life. Fortunately, kidneys function to regulate sodium chloride excretion to maintain proper levels of sodium chloride and extracellular volume when dietary salt intake changes. If the kidneys are prop...