scholarly journals In vivo Measurement of Regional Brain and Tumor pH Using [14C]Dimethyloxazolidinedione and Quantitative Autoradiography

1985 ◽  
Vol 5 (3) ◽  
pp. 369-375 ◽  
Author(s):  
James B. Arnold ◽  
Larry Junck ◽  
David A. Rottenberg
Keyword(s):  
Water Content ◽  
Gray Matter ◽  
Quantitative Autoradiography ◽  
Water Volume ◽  
Consistent Difference ◽  
Extracellular Water ◽  
Tissue Water ◽  
Constant Weight ◽  
Tumor Ph

Using [14C]dimethyloxazolidinedione ([14C]-DMO) and quantitative autoradiography, we estimated tissue pH (pHt) and intracellular pH (pHi) in nine regions of the normal rat brain and in intracerebrally implanted RG-2 gliomas. Calculations of regional pHt, based on equilibrium tissue and arterial plasma [14C]DMO concentration, ranged from 6.83 to 6.94; pHi, calculated assuming an extracellular water volume of 0.15 ml/g for gray matter and 0.11 ml/g for white matter, ranged from 6.61 to 6.78. No consistent difference was found in pH, or pHi between white and gray matter regions. Tumor tissue water content was determined by drying to constant weight, and extracellular space water volume ( Ve) was estimated with [14C]sucrose in nephrectomized rats using quantitative autoradiography. Tumor pHt ranged from 7.08 to 7.18. For Ve = 0.17 (measured), pHi was 6.94–7.06; for Ve = 0.30 (assumed), the corresponding range for pHi was 6.63–6.90. Thus, the RG-2 glioma is not more “acidic” than adjacent brain tissue and its “alkaline” pHt probably reflects a large extracellular water content and plasma-like extracellular pH.

scholarly journals Water Compartmentalization and Spread of Ischemic Injury in Thick-Slice Ischemia Model

2002 ◽  
Vol 22 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Sabina Hrabětová ◽  
Kevin C. Chen ◽  
Daniel Masri ◽  
Charles Nicholson
Keyword(s):  
Water Content ◽  
Extracellular Space ◽  
Cell Swelling ◽  
Extracellular Potassium ◽  
Tissue Water ◽  
Diffusion Analysis ◽  
Artificial Cerebrospinal Fluid ◽  
Water Redistribution ◽  
Total Tissue

Water compartmentalization was studied in a thick-slice (1000 μm) model of ischemia by combining water-content measurements with extracellular diffusion analysis. Thick slices bathed in artificial cerebrospinal fluid continually gained water. Total tissue water content was increased by 67% after 6 hours of the incubation. Diffusion measurements using the tetramethylammonium method showed that the extracellular space, typically occupying 20% of brain tissue in vivo, was decreased to 10% at 30 minutes and 15% at 6 hours in both deep and superficial layers of thick slices. Quantification of water compartmentalization revealed that water moved initially from the extracellular space into the cells. Later, however, both compartments gained water. The initial cell swelling was accompanied by dramatic shifts in potassium. An initial rise of extracellular potassium to about 50 mmol/L was measured with a potassium-selective microelectrode positioned in the center of the thick slice; the concentration decreased slowly afterwards. Potassium content analysis revealed a 63% loss of tissue potassium within two hours of the incubation. In thick slices, ionic shifts, water redistribution, and a loss of synaptic transmission occur in both deep and superficial layers, indicating the spread of ischemic conditions even to areas with an unrestricted supply of nutrients.

scholarly journals THz and mm-Wave Sensing of Corneal Tissue Water Content: In Vivo Sensing and Imaging Results

2015 ◽  
Vol 5 (2) ◽  
pp. 184-196 ◽  
Author(s):  
Zachary D. Taylor ◽  
James Garritano ◽  
Shijun Sung ◽  
Neha Bajwa ◽  
David B. Bennett ◽  
...  
Keyword(s):  
Water Content ◽  
Corneal Tissue ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Imaging Results ◽  
In Vivo Sensing

Measurement of airway mucosal perfusion and water volume with an inert soluble gas

1988 ◽  
Vol 65 (1) ◽  
pp. 264-271 ◽  
Author(s):  
A. Wanner ◽  
J. A. Barker ◽  
W. M. Long ◽  
A. T. Mariassy ◽  
A. D. Chediak
Keyword(s):  
Blood Flow ◽  
Dimethyl Ether ◽  
Transient State ◽  
Mucosal Blood Flow ◽  
Water Volume ◽  
Tracheal Mucosa ◽  
Tissue Water ◽  
Pharmacological Agents ◽  
Tracheal Mucosal Blood Flow

The purpose of this study was to develop and validate a new in vivo technique for the measurement of tracheal mucosal blood flow (Qtr) and tissue water volume (VH2O) with an inert soluble gas. The technique was based on the notion that the uptake of dimethyl ether (VDME) from an isolated tracheal segment is governed by VH2O (transient state) and Qtr (steady state). In lightly anesthetized sheep, an endotracheal tube with two cuffs placed 14.5-16.5 cm apart was placed to create a chamber into which dimethyl ether was introduced and from which VDMME into the mucosa was determined with a sensitive pneumotachograph. Mean Qtr was 1.20 ml/min (range 0.87-1.73), and mean VH2O was 1.67 ml (range 1.27-2.26). Qtr correlated with cardiac output but not with body weight or tracheal mucosal surface area determined by He dilution. VH2O did not show a correlation with any of these parameters. The response to selected pharmacological agents suggested that the measurements of Qtr and VH2O are independent of each other and from changes in tracheal diameter. Mean Qtr was 80% of mean tracheal mucosal blood flow measured with radiolabeled microspheres. We concluded that the inert soluble gas method is capable of measuring in vivo the perfusion and a water compartment of the intact tracheal mucosa.

scholarly journals PVCURVE: A COMPUTER SPREADSHEET TEMPLATE FOR EVALUATING PRESSURE-VOLUME CURVES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1096e-1096
Author(s):  
Robert Augé
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Accurate Estimate ◽  
Water Volume ◽  
Tissue Water ◽  
Additional Information ◽  
Spreadsheet Analysis ◽  
Spreadsheet Template ◽  
Total Tissue

The determination of tissue water potential components is important for understanding plant growth and response to the environment. Pressure-volume (PV) analysis is often considered to give the most accurate estimate of symplastic osmotic potential. Additional information about tissue water relations can also be computed from PV curves estimates of bulk cell wall elasticity, symplastic water volume, and turgor potential at various states of tissue water content. The generation of PV curves is a time-consuming procedure, however, and involves considerable computation. This presentation describes a computer spreadsheet template for traditional evaluation of a PV curve through linear regression of the zero turgor segment. The template allows real-time plotting of the inverse ψ/ water loss relating, provides estimates of most commonly calculated PV characteristics and permits instant graphic visualizations of changes in water potential components and elasticity with changes in water potential, total tissue water and symplastic water content. The advantages of spreadsheet analysis of PV curves are simplicity, consistency, thoroughness and speed. A fleeting acquaintance with spreadsheet software and a thorough understanding of pressure-volume theory on the part of the user is assumed.

Autoradiography of the water compartments in developing teeth of young mice

1977 ◽  
Vol 232 (4) ◽  
pp. F358-F363
Author(s):  
G. E. Lyman ◽  
W. J. Waddell
Keyword(s):  
Water Content ◽  
Electron Microprobe ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Radioactive Material ◽  
Reliable Indicator ◽  
Extracellular Water ◽  
Tissue Water ◽  
Water Compartments ◽  
Total Tissue

The distribution of [14C-a1acetyl-4-aminoantipyrine ([14C]NAAP), as indicators of total tissue water, and [carboxy-14C]inulin ([14C]inulin), as an indicator of extracellular water, were studied by autography in mice 4-16 days old. An autographic technique was used that does not translocate or remove the radioactive material. Photometric densities of the autoradiographs revealed wide variations in radioactivity among the various areas of the teeth. Evidence for binding of [14C]urea to bone limits the usefulness of this compound as an indicator. Although [14C]inulin appeared to be a reliable indicator, it is difficult to correlate its distribution with the progress of mineralization determined by electron microprobe analysis. [14C]NAAP was considered to be the most reliable indicator; it revealed that the water content of various areas of the teeth ranged from 7 to 100% of that in blood.

scholarly journals In vivo Measurement of Regional Brain and Tumor pH Using [14C]Dimethyloxazolidinedione and Quantitative Autoradiography. II: Characterization of the Extracellular Fluid Compartment Using pH-Sensitive Microelectrodes and [14C]Sucrose

1986 ◽  
Vol 6 (4) ◽  
pp. 435-440 ◽  
Author(s):  
James B. Arnold ◽  
Richard P. Kraig ◽  
David A. Rottenberg
Keyword(s):  
Brain Tissue ◽  
Extracellular Space ◽  
Extracellular Fluid ◽  
Water Volume ◽  
Normal Brain ◽  
In Vivo Measurement ◽  
Tumor Ph ◽  
Fluid Compartment ◽  
Arterial Ph

We measured the extracellular (interstitial) pH (pHe) of RG-2 rat gliomas using H+-sensitive microelectrodes and estimated the volume of tumor extracellular space based on the tissue-plasma ratio of [14C]sucrose. The average RG-2 pHe was 7.63 ± 0.15 (mean ± SD, n = 6), whereas the average pHe of contralateral brain tissue was 7.34 ± 0.10 (n = 3) and arterial pH was 7.36 ± 0.02. RG-2 extracellular space water volume was estimated to be 0.3 ml water/g tissue. In separate experiments in normal, nontumored rats, intracellular pH (pHi) was calculated for nine gray and white matter regions based on measurements of tissue and plasma [14C]dimethyloxazolidinedione concentration. pHi values ranged from 6.80 to 6.94, and no consistent gray–white differences were observed. Our data suggest that tumor pHi is not more acidic than that of normal brain tissue and that the observed alkalinity of primary brain tumors is due to the presence of a large alkaline extracellular space.

Spectroscopic imaging of human disease

1996 ◽  
Vol 54 ◽  
pp. 884-885
Author(s):  
D.J. Meyerhoff
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Human Disease ◽  
Morphological Changes ◽  
Magnetic Field Gradient ◽  
Spectroscopic Imaging ◽  
Resonance Spectroscopy ◽  
Tissue Water

Magnetic Resonance Imaging (MRI) observes tissue water in the presence of a magnetic field gradient to study morphological changes such as tissue volume loss and signal hyperintensities in human disease. These changes are mostly non-specific and do not appear to be correlated with the range of severity of a certain disease. In contrast, Magnetic Resonance Spectroscopy (MRS), which measures many different chemicals and tissue metabolites in the millimolar concentration range in the absence of a magnetic field gradient, has been shown to reveal characteristic metabolite patterns which are often correlated with the severity of a disease. In-vivo MRS studies are performed on widely available MRI scanners without any “sample preparation” or invasive procedures and are therefore widely used in clinical research. Hydrogen (H) MRS and MR Spectroscopic Imaging (MRSI, conceptionally a combination of MRI and MRS) measure N-acetylaspartate (a putative marker of neurons), creatine-containing metabolites (involved in energy processes in the cell), choline-containing metabolites (involved in membrane metabolism and, possibly, inflammatory processes),

scholarly journals Isoflurane in Contrast to Propofol Promotes Fluid Extravasation during Cardiopulmonary Bypass in Pigs

2013 ◽  
Vol 119 (4) ◽  
pp. 861-870 ◽  
Author(s):  
Hege Kristin Brekke ◽  
Stig Morten Hammersborg ◽  
Steinar Lundemoen ◽  
Arve Mongstad ◽  
Venny Lise Kvalheim ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
Water Content ◽  
Interstitial Fluid ◽  
Outcome Analysis ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Edema Formation ◽  
Fluid Extravasation ◽  
Isoflurane Anesthesia ◽  
Total Tissue

Abstract Background: A highly positive intraoperative fluid balance should be prevented as it negatively impacts patient outcome. Analysis of volume-kinetics has identified an increase in interstitial fluid volume after crystalloid fluid loading during isoflurane anesthesia. Isoflurane has also been associated with postoperative hypoxemia and may be associated with an increase in alveolar epithelial permeability, edema formation, and hindered oxygen exchange. In this article, the authors compare fluid extravasation rates before and during cardiopulmonary bypass (CPB) with isoflurane- versus propofol-based anesthesia. Methods: Fourteen pigs underwent 2 h of tepid CPB with propofol (P-group; n = 7) or isoflurane anesthesia (I-group; n = 7). Fluid requirements, plasma volume, colloid osmotic pressures in plasma and interstitial fluid, hematocrit levels, and total tissue water content were recorded, and fluid extravasation rates calculated. Results: Fluid extravasation rates increased in the I-group from the pre-CPB level of 0.27 (0.13) to 0.92 (0.36) ml·kg−1·min−1, but remained essentially unchanged in the P-group with significant between-group differences during CPB (pb = 0.002). The results are supported by corresponding changes in interstitial colloid osmotic pressure and total tissue water content. Conclusions: During CPB, isoflurane, in contrast to propofol, significantly contributes to a general increase in fluid shifts from the intravascular to the interstitial space with edema formation and a possible negative impact on postoperative organ function.

Water content of rat adipose tissue and isolated adipocytes in relation to cell size

1976 ◽  
Vol 231 (5) ◽  
pp. 1568-1572 ◽  
Author(s):  
M DiGirolamo ◽  
JL Owens
Keyword(s):  
Adipose Tissue ◽  
Water Content ◽  
Cell Volume ◽  
Cell Size ◽  
Intracellular Water ◽  
Male Rats ◽  
Fat Cells ◽  
Fat Cell ◽  
Tissue Water ◽  
Adipose Mass

Epididymal adipose tissue composition and adipocyte water content were studied in male rats during growth and development of spontaneous obesity. The data show that a highly significant positive correlation exists between fat-cell volume and intracellular water space (IWS) (r=.967, P less than .001). Intracellular water, expressed as picoliters per fat cell, varied from 1.5-2 in small fat cells (mean vol, 30-50 pl) to 9-10 in large cells (800-1,000 pl). When expressed as percent of fat-cell volume, IWS varied from 5-7% in the small fat cells to 1-1.3% in the large ones. Total adipose tissue water continued to increase with increasing adipose mass. Similarly, total adipocyte water increased with enlarging cell size and tissue mass. The contribution of total adipocyte water (as contrasted to that of nonadipocyte water) to total tissue water, however, was found to be limited (less than 23%) and to decline progressively with adipose mass expansion.

scholarly journals Aromatase inhibitors in breast cancer.

2004 ◽  
Vol 11 (2) ◽  
pp. 179-189 ◽  
Author(s):  
P E L√∏nning
Keyword(s):  
Breast Cancer ◽  
Aromatase Inhibitors ◽  
Cancer Biology ◽  
Postmenopausal Breast Cancer ◽  
Phase Iii ◽  
Cross Resistance ◽  
Consistent Difference ◽  
Clinical Effects ◽  
Endocrine Regulation

The development of aromatase inhibitors for breast cancer therapy is a result of successful translational research exploring the biochemical effects of different compounds in vivo. Studies assessing plasma oestrogen levels as well as in vivo aromatase inhibition have revealed a consistent difference with respect to biochemical efficacy between the third generation compounds (anastrozole, letrozole and exemestane) and the previous, first and second generation drugs, corresponding to the improved clinical effects of these compounds as outlined in large phase III studies. Thus, endocrine evaluation has been found to be a valid surrogate parameter for clinical efficacy. Moreover, the results from these studies have added important biological information to our understanding of endocrine regulation of breast cancer. Based on the clinical results so far, aromatase inhibitors are believed to play a key role in future adjuvant therapy of postmenopausal breast cancer patients and potentially also for breast cancer prevention. Interesting findings such as the lack of cross-resistance between steroidal and non-steroidal compounds should be further explored, as this may add additional information to our understanding of breast cancer biology.

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