Search results for "Concentration"

Is there a critical tissue oxygen tension for bioenergetic status and cellular pH regulation in solid tumors?

1996

Bioenergetic and metabolic status have been correlated with tissue oxygenation in murine fibrosarcomas (FSaII) of varying sizes (44-600 mm3). Ratios of beta-nucleoside triphosphates to inorganic phosphate (beta NTP/P) and phosphocreatine to inorganic phosphate (PCr/P(i)) ratios derived from 31P nuclear magnetic resonance spectroscopy (NMR) were positively correlated to median tissue O2 tension (pO2) values using O2-sensitive needle electrodes. pH declined during growth with intracellular acidosis being evident in tumors350 mm3. Whereas lactic acid formation greatly contributed to this decline in small and medium-sized tumors, adenosine triphosphate (ATP) hydrolysis and slowing down of the a…

Intracellular acidosis in murine fibrosarcomas coincides with ATP depletion, hypoxia, and high levels of lactate and total Pi

1994

Bioenergetic and metabolic status of murine FSaII tumours were evaluated using 31P MRS, acid extracts ('global' techniques) and quantitative bioluminescence ('microregional' assay). Data obtained from s.c. tumours of varying sizes (44-600 mm3) have been correlated with the oxygenation status evaluated using O2-sensitive needle electrodes. beta-NTP/Pi and phosphocreatine (PCr)/Pi ratios derived from 31P MRS were positively correlated to the median tissue pO2 values. pH declined during growth with intracellular acidosis being evident in tumours > 350 mm3. Whereas lactic acid formation greatly contributed to this decline in small- and medium-sized tumours, ATP hydrolysis and slowing down of th…

Prediction of dilutional acidosis based on the revised classical dilution concept for bicarbonate

2004

Due to the controversy surrounding the term dilutional acidosis, the classical dilution concept for bicarbonate has been rigorously revised for the prediction of pH, actual bicarbonate concentration, and base excess. In the algorithms derived for buffer solutions, blood, and whole body (1-, 2-, and 3-fluid compartment), only bicarbonate is considered. On dilution at constant Pco2, the final concentration of bicarbonate is the sum in terms of pH, due to the following processes: dilution, formation from chemical reaction with the nonbicarbonate buffers phosphate, hemoglobin, and plasma proteins, and transfer from erythrocytes and interstitial fluid to plasma. At constant Pco2, the level of c…

Base Excess and Lactate Concentration in Infusion Solutions and Blood Products

2002

Prenatal manganese serum levels and neurodevelopment at 4 years of age

2020

Abstract Background The excess of manganese (Mn) causes severe deleterious effects in the central nervous system, and the developing brain is especially sensitive to Mn overload. However, results of prospective studies regarding Mn neurodevelopmental effects remain inconclusive. The present study aims at studying the association of prenatal Mn exposure and neurodevelopment at 4–5 years of age. Methods: Mn serum concentration was measured in 1465 pregnant women from the INMA (INfancia y MedioAmbiente, Environment and Childhood) Project. Neurodevelopment was assessed using a standardized version of the McCarthy Scales of Children's Abilities (MSCA). Multivariate regression models were used fo…

Normal Values of Oxygen Concentration in Human Blood

1984

Under physiological conditions, the oxygen supply as the product of O2-concentration (mlO2/dl; %(v/v)) and perfusion is influenced by many factors (cf. Fig. 1): perfusion on one hand, oxygen partial pressure (pO2; mmHg), haemoglobin (Hb) concentration (g/dl) and O2 binding power of Hb on the other hand. Under pathological conditions, oxygen supply disturbances are related to hypoxemia, i.e. reduction of O2-concentration in the blood. The differential diagnosis of hypoxemia includes normoxic, hypoxic and circulatoric disturbances of oxygen supply (cf. Fig. 1). Thus it is necessary to describe a NORMOXIC HYPOXEMIA (anemic or toxemic), a HYPOXIC HYPOXEMIA (decreased O2-concentration caused by …

Muscarinic mobilization of choline in rat brain in vivo as shown by the cerebral arterio-venous difference of choline.

1987

In anesthetized rats, the choline levels of cerebrospinal fluid and plasma obtained from blood collected from peripheral vessels (carotid artery, cardiac vessels) and from the transverse sinus were determined with a radioenzymatic assay. Cortical release of choline was studied using the "cup technique." The plasma choline level of the peripheral blood (11.5 mumol/L) was lower than that of the sinus blood. The resulting cerebral arterio-venous difference of choline was negative (3.2 mumol/L) and reflected the net release of choline from the whole brain. The plasma choline levels were not different irrespective of whether the rats were anesthetized with ether, urethane, or pentobarbital. Howe…

Hypercholesterolemia and haemostatic function changes

1990

Patients with hypercholesterolemia have elevated levels of LDL and reduced plasma concentration of HDL.

Medical and occupational preconditions for vibration-induced spinal disorders: occupational disease no. 2110 in Germany.

1994

The current state of scientific knowledge of the biodynamic behaviour of the vertebral column under the influence of whole-body vibration whilst sitting and results from epidemiological studies caused the medical board of experts on occupational health of the Federal Ministry of Labour in Germany to add a new occupational disease to the official list of occupational diseases. The occupational disease “diseases of the lumbar spine from disc degeneration caused by long-term (mainly vertical) whole-body vibration exposure” has been introduced. The medical preconditions with the symptoms and the diagnostic methods are presented. With regard to the occupational preconditions for the acknowledgem…

P01-92 - Early Changes are Associated with late Changes of BDNF Serum Levels in Inpatients with Major Depression During Short-term Antidepressant Tre…

2010

ObjectivesMean BDNF serum concentration is lower in patients with major depression (MD) as compared to healthy controls. BDNF increases during the course of antidepressant treatment. This increase has been associated with symptom amelioration. The aim of this study was to analyse the relation between early and late BDNF changes during antidepressant treatment.MethodsForty-six patients with MD according to DSM-IV were included for this study. Patients were treated as clinically indicated. Depression severity was assessed by HAMD-17 by trained raters from baseline to week 6 in weekly intervals. Serum at each visit (baseline, V1-V6) was obtained from whole blood after centrifugation with 1.000…