Search results for "BICARBONATE"
showing 10 items of 119 documents
A proton-translocating H+-ATPase is involved in C6 glial pH regulation.
1998
AbstractGlial cells extrude acid equivalents to maintain pHi. Although four mechanisms have been described so far, pHi-control under physiological conditions is still not sufficiently explained. We therefore investigated whether a H+-translocating ATPase is involved in glial pHi homeostasis using an established glial cell line (C6 glioma). In the absence of bicarbonate, the inhibition of H+-ATPases by NEM led to a pHi decrease. The application of a more specific inhibitor (NBD-Cl) showed that the H+-ATPase involved is of the vacuolar type. Inhibition went along with delayed cell swelling. Together with the fact that glial acidification was far more pronounced in Na+-free media, this may ser…
Endothelial Cell Swelling and Brain Perfusion
1997
Background: Whereas the contribution of glial swelling to no-reflow conditions in the ischemic penumbra or during reperfusion after global ischemia is widely discussed, little is known about cell volume control of endothelial cells under reperfusion conditions. Methods: The effect of extracellular acidosis-a key mediator of secondary brain damage-on cell volume was studied in the GM7373 endothelial cell line. Experiments were performed at pH = 6.0 in the presence or absence of bicarbonate, and during exposure to inhibitors of specific transport systems such as ethyl isopropyl amiloride or 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid. Results: Endothelial swelling to 111.1 ± 3.4% was f…
Ibuprofen degradation using a Co-doped carbon matrix derived from peat as a peroxymonosulphate activator
2021
The wider presence of pharmaceuticals and personal care products in nature is a major cause for concern in society. Among pharmaceuticals, the anti-inflammatory drug ibuprofen has commonly been found in aquatic and soil environments. We produced a Co-doped carbon matrix (Co-P 850) through the carbonization of Co2+ saturated peat and used it as a peroxymonosulphate activator to aid ibuprofen degradation. The properties of Co-P 850 were analysed using field emission scanning electron microscopy, energy filtered transmission electron microscopy and X-ray photoelectron spectroscopy. The characterization results showed that Co/Fe oxides were generated and tightly embedded into the carbon matrix …
Modelling the transport of carbonic acid anions through anion-exchange membranes
2003
Electrodiffusion of carbonate and bicarbonate anions through anion-exchange membranes (AEM) is described on the basis of the Nernst � /Planck equations taking into account coupled hydrolysis reactions in the external diffusion boundary layers (DBLs) and internal pore solution. The model supposes local electroneutrality as well as chemical and thermodynamic equilibrium. The transport is considered in three layers being an anion exchange membrane and two adjoining diffusion layers. A mechanism of
pH and salivary sodium bicarbonate during the administration protocol for methotrexate in children with leukemia
2007
Objective: To analyze the behavior of pH and sodium bicarbonate (NAHCO3) in the saliva of patients with leukemia during the administration protocol for Methotrexate (Mtx). Materials and Methods: A controlled clinical essay was carried out on 23 patients between 4 and 18 years of age with high-risk Acute Lymphoblastic Leukemia. Sampling was carried out at To : basal condition; T1 : 12 hours after intravenous administration of sodium bicarbonate, before administering Mtx and T2 : 3 hours after administering Mtx, the time of maximum concentration. Chiron-Diagnostic 378® equipment was used to determine pH and sodium bicarbonate. The data was interpreted using Analysis of Variance at the 5% sign…
The accuracy of calculated base excess in blood.
2002
Most equations used for calculation of the base excess (BE, mmol/l) in human blood are based on the fundamental equation derived by Siggaard-Andersen and called the Van Slyke equation: BE = Z x [[cHCO3-(P) - C7.4 HCO3-(P)] + beta x (pH -7.4)]. In simple approximation, where Z is a constant which depends only on total hemoglobin concentration (cHb, g/dl) in blood, three equations were tested: the ones proposed by Siggaard-Andersen (SA), the National Committee for Clinical Laboratory Standards (NCCLS) or Zander (ZA). They differ only slightly in the solubility factor for carbon dioxide (alphaCO2, mmol/l x mmHg) and in the apparent pK(pK'), but more significantly in the plasma bicarbonate conc…
Mineralization of bone-related SaOS-2 cells under physiological hypoxic conditions
2015
Inorganic polyphosphate (polyP) is a physiological energy-rich polymer with multiple phosphoric anhydride bonds. In cells such as bone-forming osteoblasts, glycolysis is the main pathway generating metabolic energy in the form of ATP. In the present study, we show that, under hypoxic culture conditions, the growth/viability of osteoblast-like SaOS-2 cells is not impaired. The addition of polyP to those cells, administered as amorphous calcium polyP nanoparticles (aCa-polyP-NP; approximate size 100 nm), significantly increased the proliferation of the cells. In the presence of polyP, the cells produce significant levels of lactate, the end product of anaerobic glycolysis. Under those conditi…
The importance of potassium citrate and potassium bicarbonate in the treatment of uric acid renal stones
2017
Uric acid calculi can also be treated without surgery, with simple medical lytic therapy. After appropriate dietary adjustments and add of mineral water, the needed amount of alkali supplementation can increase pH values of the urine in order to dissolve the stones. Treatment should be prolonged to prevent stone recurrence. A case of bilateral renal uric acid stones that were successfully treated by alakalizing treatment was presented.
Model-Based Decision Support System for Individual Prescription of the Dialysate Bicarbonate Concentration in Hemodialysis
1992
A decision support system has been developed that determines the optimal dialysate bicarbonate concentration in hemodialysis therapy for each patient individually. The knowledge about the behavior of the acid-base state during treatment has been provided by a mathematical model for the description of dynamic exchange processes during hemodialysis. This model simulates the sodium and water distribution, the acid-base state as well as the ventilation. The decision support system uses the model for the prediction of the end-dialysis acid-base state and calculates by means of linear optimization the dialysate bicarbonate concentration which is necessary to reach a specified end-dialysis state.…
Improving the mechanical properties of unidirectional flax fabrics reinforced epoxy composites by sodium bicarbonate treatment
2017
Despite their beneficial effects on the adhesion between natural fibers and polymeric matrices, chemical pretreatments have become less attractive since they are expensive and harmful to environment. The present paper deals with the effect of an eco-friendly and cost effective treatment, based on the use of a sodium bicarbonate solution, on the mechanical performances of flax reinforced epoxy composites. Materials and methods: A commercial epoxy resin and unidirectional flax fabrics (190 g/m2 areal density) were used as matrix and reinforcement, respectively. The fabrics were soaked in 5 and 10 wt% solutions of sodium bicarbonate for 5 days at 25°C, then dried at 105°C for 1 day. By using u…