Erythropoietin in the cerebrospinal fluid of patients with aneurysmal subarachnoid haemorrhage originates from the brain.

Recent years' research has revealed a specific, neuroprotective erythropoietin (EPO) system in the central nervous system (CNS) that is upregulated by hypoxia. The presence and dynamics of EPO in the cerebrospinal fluid (CSF) of patients with subarachnoid haemorrhage (SAH) has not been investigated. We collected a total of 83 corresponding serum and CSF samples from 18 patients with aneurysmal SAH and compared the concentrations of EPO with those of blood-derived markers of blood-brain barrier function (albumin, transferrin, alpha(2)-macroglobulin) and with those of proteins with well-known CNS synthesis (prealbumin, apolipoprotein E).

Sympathetic control of hemodynamics during moderate head-up tilt in human subjects.

To confirm sympathetic control of hemodynamics during postural change, sympathetic nerve activity supplying the anterior tibial muscle (MSNA) was measured by microneurography and muscle blood flow (MBF) by the xenon washout method during graded head-up tilt from 0 degrees horizontal to 30 degrees in 5 degrees increments. MSNA was represented as the increase in burst rate with increased tilt angle. The increments of MSNA from 0 degree horizontal were statistically significant at all tilt angles.

Central venous pressure in humans during microgravity.

Based on the results of head-down simulation studies and the results of parabolic flights, the hypothesis was tested that central venous pressure (CVP) in humans increases during microgravity (weightlessness) compared with during the ground-based supine position. CVP was recorded with an intravascular pressure transducer in seven healthy humans during short (20-s) periods of microgravity created by parabolic-flight maneuvers and in one astronaut before, during, and up to 3 h after launch of the Spacelab D-2 mission (Space Transport System-55). When the subjects were supine during the parabolic maneuver, CVP decreased during microgravity from 6.

Relative role of low- and high pressure reflexes on sympathetic activity in humans during simulated gravitational stress.

In order to determine the relative role of low- and high-pressure reflexes, respectively, on forearm sympathetic nerve activity (fSNA), 10 normal male subjects underwent a 4-step (5 min each) graded lower body negative pressure (LBNP) from -10 to -50 mmHg. Central venous pressure (CVP) and stroke volume gradually decreased (p<0.05), and arterial pulse pressure (PP) abruptly decreased at LBNP of -50 mmHg.

Volume-homeostatic mechanisms in humans during a 12-h posture change.

On one day six male subjects underwent an upright seated (SEAT) study, and on another day they were subjected to a head-down tilt of 3 degrees (HDT). Compared with SEAT, HDT induced prompt increases in central venous pressure (CVP) from -0.5 +/- 0.

Plasma volume, fluid shifts, and renal responses in humans during 12 h of head-out water immersion.

Changes in plasma volume (PV) throughout 12 h of thermoneutral (34.5 degrees C) water immersion (WI) were evaluated in eight subjects by an improved Evans blue (EB) technique and by measurements of hematocrit (Hct), hemoglobin (Hb), and plasma protein concentrations (Pprot). Appropriate time control studies (n = 6) showed no measurable change in PV.

Circulation, kidney function, and volume-regulating hormones during prolonged water immersion in humans.

To investigate whether prolonged water immersion (WI) results in reduction of central blood volume and attenuation of renal fluid and electrolyte excretion, these variables were measured in connection with 12 h of immersion. On separate days, nine healthy males were investigated before, during, and after 12 h of WI to the neck or during appropriate control conditions. Central venous pressure, stroke volume, renal sodium (UNaV) and fluid excretion increased on initiation of WI and thereafter gradually declined but were still elevated compared with control values at the 12th h of WI.

Telescience testbed in human space physiology.

The present telescience testbed study was conducted to evaluate the feasibility of physiological experimentation under restricted conditions such as during simulated weightlessness induced by using a water immersion facility, a reduced capacity of laboratory facilities, a delay and desynchronization of communication between investigator and operator, restrictions of different kinds of experiments practiced by only one operator following a limited time line and so on. The three day's experiments were carried out following the same protocols. The operators were changed every day, but was the same the first and the third day.

Repeated plasma volume determination with the Evans Blue dye dilution technique: the method and a computer program.

This paper describes a reliable multiple sample Evans Blue dye dilution technique and a Pascal program which computes plasma and blood volume on the basis of this technique. The program performs needed corrections and dye disappearance curve fitting. It provides menu-driven facilities for data correction, graphic display of the dye disappearance curve, and print-out of all the involved data.

pH effect on the COHb absorption spectrum: importance for calibration of the OSM3 and measurement of circulating hemoglobin and blood volume.

An easy method to measure blood volume is clinically needed. We used carbon monoxide (CO) and the OSM3 to measure circulating hemoglobin and blood volume with the indicator dilution principle. 50 mL of CO was administered into a closed rebreathing system and taken up via the lungs, and the amount of hemoglobin in the blood was calculated from the increase in carboxyhemoglobin fraction after 10 min.

Human cardiovascular reactions to simulated hypovolaemia, modified by the opiate antagonist naloxone.

Six healthy males were exposed to 20 mm Hg lower body negative pressure (LBNP) for 8 min followed by 40 mm Hg LBNP for 8 min. Naloxone (0.1 mg.

Central venous pressure in humans during short periods of weightlessness.

Central venous pressure (CVP) was measured in 14 males during 23.3 +/- 0.6 s (mean +/- SE) of weightlessness (0.