Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Solutions”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,243 records · Page 69Linked to original sources
PubMed2005

Amoebicidal activity of multipurpose contact lens solutions.

PURPOSE: To compare the amoebicidal activity of two commercially available multipurpose contact lens care systems, by using cyst and trophozoite growth of two strains each of Acanthamoeba castellanii and Acanthamoeba polyphaga. METHODS: Trophozoites and cysts of Acanthamoeba species, isolated from corneal ulcers and an ATCC strain, were exposed to two commonly used multipurpose solutions and a saline control for 4 or 6 hours at ambient temperature. After neutralization of the disinfecting solution, track forming units were enumerated on Escherichia coli-seeded nutrient agar plates. RESULTS: There were significant differences (P<0.01) between solutions, strains, and cysts or trophozoites, but not between the different periods. Solution 2, containing polyquaternium-1 and myristamidopropyl dimethylamine (among other ingredients), gave greater mean log reductions than did solution 1, containing polyaminopropyl biguanide and poloxamine (among other ingredients). Both solutions generally reduced more trophozoites than cysts. CONCLUSIONS: The multipurpose solution containing polyquaternium-1 and myristamidopropyl dimethylamine reduced more cysts and trophozoites than did the alternative solution tested. Because there were differences in the effect of the multipurpose solutions on strains, it is recommended that more than one strain or species of Acanthamoeba be tested to determine efficacy of disinfecting solutions. The lack of difference between disinfection times may indicate that 4 hours could be considered as an adequate disinfecting time to ensure sufficient kill of Acanthamoeba species.

Acanthamoeba castellanii↗
PubMed1998

Bicarbonate and bicarbonate/lactate peritoneal dialysis solutions for the treatment of infusion pain.

A randomized, double-blind, cross-over study was undertaken to determine the effects of novel bicarbonate (38 mM) and bicarbonate (25 mM)/lactate (15 mM) containing peritoneal dialysis (PD) solutions on infusion pain in patients who experienced inflow pain with conventional lactate (40 mM) solution. Pain was assessed using a verbal rating scale and the validated McGill Pain Questionnaire (MPQ). Eighteen patients were recruited to the study. Both novel solutions resulted in highly statistically significant reductions in inflow pain compared to the control lactate solution, as assessed with both the verbal rating scale and the MPQ. For all pain variables assessed, the bicarbonate/lactate solution was more effective than the bicarbonate solution in alleviating pain. In conclusion, both solutions reduced the infusion pain experienced with control solution, but the bicarbonate/lactate solution appears to be the most effective. In contrast to the most widespread current treatment, which is the manual injection of sodium bicarbonate, the bicarbonate/lactate solution does not have the associated increased risk of peritonitis.

Bicarbonates↗
PubMed1996

The intraocular pressure lowering effect of timolol in gel-forming solution.

The effect on the intraocular pressure (IOP) of 0.5% timolol solution given twice daily was compared to 0.5% timolol in gel-forming solution given once daily. Patients (n = 223) having an IOP of above 22 mmHg were recruited from 16 eye specialist centres in Scandinavia and Finland. The patients were randomized to two treatment groups, timolol solution treatment and timolol in gel-forming solution treatment. Eyes with and without pseudoexfoliation were included. The patients were stratified regarding the presence or not of pseudoexfoliation, to ensure appropriate distribution of this condition. No difference in intraocular pressure reducing effect was registered for the two groups. The pressure reducing effect of the two modes of treatment was not affected by the presence or not of pseudoexfoliation. The study also included registration of local and systemic signs and symptoms possibly related to the study medications. Blurring of vision occurred more often in patients given 0.5% timolol in gel-forming solution compared to timolol solution. The heart rate decreased statistically significantly in patients given timolol solution, but not in patients given timolol in gel-forming solution. This study suggests that treatment with 0.5% timolol in gel-forming solution once a day may be equally as good as 0.5% timolol solution given twice a day in patients with glaucoma both with and without pseudoexfoliation.

Adrenergic beta-Antagonists↗
PubMed1991

Search for the ideal oral rehydration solution: studies in a model of secretory diarrhoea.

In situ perfusion of whole rat small intestine was used to compare the efficacy of five oral rehydration solutions in promoting water and sodium absorption in normal intestine and secreting intestine after exposure to cholera toxin. Solutions varied in their sodium (35-90 mmol/l) and glucose (111-200 mmol/l) concentrations, molar ratio of glucose:sodium (1.2-5.8), and osmolality (281-331 mOsmol/kg), and contained either bicarbonate (18-30 mmol/l) or citrate (10 mmol/l). In normal intestine all solutions promoted net water absorption. Cholera toxin induced reproducible water secretion but all solutions reversed this to absorption. Water absorption was greatest with solutions containing sodium 60 mmol/l and glucose 111 or 140 mmol/l, and with a glucose:sodium ratio approximately 2, in both normal and secreting intestine. All solutions promoted net glucose absorption in both normal and secreting intestine. Net sodium absorption occurred with solutions containing greater than or equal to 60 mmol/l sodium in normal intestine but sodium secretion occurred from all solutions in secreting intestine. Sodium movement was directly related to the sodium concentration of the solution and sodium secretion occurred despite net water and glucose absorption. We consider that these studies may guide future development of oral rehydration solutions.

Animals↗
PubMed1994

Regulation of intracellular pH in cardiac muscle during cell shrinkage and swelling in anisosmolar solutions.

The effect on intracellular pH (pHi) of exposure to solutions of progressively increasing osmolarity from 418 to 620 mosM and to hyposmolar solutions (240 mosM) was examined in guinea pig ventricular muscle using ion-selective microelectrodes. Exposure of tissue to 418 mosM Tyrode solution (100 mM sucrose added) produced an intracellular alkalosis of approximately 0.1 U, whereas exposure to 620 mosM solution (300 mM sucrose added) caused an intracellular acidosis of approximately 0.1 U. The maximal rate of recovery of pHi from acidosis induced by an NH4Cl prepulse increased progressively as extracellular osmolarity was raised from 310 to 620 mosM. This suggests that the acidosis observed at steady state in 620 mosM solution is not due to inhibition of the Na(+)-H+ exchanger. In the presence of 10 microM ryanodine, exposure to 620 mosM solution produced a sustained intracellular alkalosis. We suggest that the decrease in pHi during exposure to 620 mosM solution is due, at least in part, to the acidifying influence of Ca2+ release from the sarcoplasmic reticulum. This decrease in pHi is expected to contribute to the negative inotrop reported in studies of cardiac contractility in markedly hyperosmolar solutions. There was no change in pHi when tissue was exposed to hyposmolar solution. However, the maximal rate of recovery of pHi from acidosis was slower in hyposmolar than in isosmolar solution, despite a concomitant decrease in the intracellular buffer capacity. This suggests that osmotic cell swelling results in inhibition of the sarcolemmal Na(+)-H+ exchanger.

Amiloride↗
PubMed1997

Remineralization of enamel subsurface lesions by casein phosphopeptide-stabilized calcium phosphate solutions.

Casein phosphopeptides (CPP) stabilize amorphous calcium phosphate (ACP), localize ACP in dental plaque, and are anticariogenic in animal and in situ human caries model. In this vitro study, CPP-stabilized calcium phosphate solutions were shown to remineralize subsurface lesions in human third-molar enamel. Solutions were used to examine the effect of CPP-calcium phosphate concentration on remineralization. Other solutions were used to examine the effect of increasing pH, which decreased the concentrations of free calcium and phosphate ions and increased the level of CPP-bound ACP. Although most of the remineralizing solutions were supersaturated with respect to the amorphous and crystalline calcium phosphate phases, the solutions were stabilized by the CPP such that spontaneous precipitation of calcium phosphate did not occur. After a ten-day remineralization period, enamel lesions were sectioned, subjected to microradiography, and the mineral content determined by microdensitometry. All solutions deposited mineral into the bodies of the lesions, with the 1.0% CPP-calcium phosphate (pH 7.0) solution replacing 63.9 +/- 20.1% of mineral lost at an averaged rate of 3.9 +/- 0.8 x 10(-8) mol hydroxyapatite/m2/s. The remineralizing capacity was greater for the solutions with the higher levels of CPP-stabilized free calcium and phosphate ions. Remineralization was not significantly correlated with either the CPP-bound ACP of the degrees of saturation for hydroxyapatite, octacalcium phosphate, or ACP. However, remineralization was significantly correlated with the degree of saturation for dicalcium phosphate dihydrate (CaHPO4.2H2O), but his was attributed to the significant correlation of remineralization with the activity gradients from the solution into the lesion of some calcium phosphate ions and ion pairs, in particular the neutral ion pair CaHPO4(0). The CPP, by stabilizing calcium phosphate in solution, maintain high-concentration gradients of calcium and phosphate ions and ion pairs into the subsurface lesion and thus effect high rates of enamel remineralization.

Calcium↗
PubMedDate not supplied

The solubility of calcium and phosphate in two specialty amino acid solutions.

BACKGROUND: The purpose of this study was to determine precipitation limits and construct curves for calcium and phosphorus in parenteral nutrition solutions compounded with specialty amino acid solutions. METHODS: The effect of temperature, concentration of amino acids, and pH on the solubility of calcium and phosphate was studied for two specialized amino acid solutions: NephrAmine and HepatAmine. Ten amino acid solutions were manufactured with NephrAmine and 12 with HepatAmine at amino acid concentrations of 0.8%, 1.5%, and 2%. The final dextrose concentration was 10%. Some of the solutions were tested with the additive cysteine hydrochloride, 40 mg cysteine/g of protein, and some were buffered with sodium bicarbonate or hydrochloric acid to model the pH of a combined fat emulsion and total parenteral nutrient (TPN) solution. Calcium gluconate and potassium phosphate were added to test samples of each TPN solution. A range of calcium concentrations of 2.5 to 40 mEq/L and phosphate concentrations of 2.5 to 40 mmol/L were tested. After storage at room temperature (25 degrees C) for 18 hours, solutions were inspected for precipitation. At the end of the 18-hour period, the solutions were held in a water bath at 37 degrees C for 30 minutes and inspected for precipitation and microcrystallization. RESULTS: Solubility curves were plotted to represent Ca-PO4 solubility limits before visual or microscopic precipitation. These curves depend on the variables of time, temperature, concentration, and pH. CONCLUSIONS: These data and graphs will help the clinical pharmacist estimate Ca-PO4 solubility limits and prevent precipitation of TPN solutions formulated with NephrAmine or Hepatamine.

Amino Acids↗
PubMed2005

Prevention of peritoneal sclerosis: a new proposal to substitute glucose with carnitine dialysis solution (biocompatibility testing in vitro and in rabbits).

AIM: Commercial glucose peritoneal dialysis solutions expose the peritoneum to hyperosmolar glucose containing variable amounts of non-enzymic breakdown products of glucose. These solutions are toxic for the peritoneum. The aim of the present study is to compare in vitro and in vivo characteristics of a new dialysis solution containing carnitine, a naturally occurring compound, as substitute of glucose. MATERIAL AND METHODS: We compared in vitro and in the rabbit a new peritoneal dialysis solution containing carnitine, with two standard bicarbonate glucose peritoneal dialysis solutions and a solution containing icodextrin. RESULTS: In vitro and in vivo the solution containing carnitine seems to be more biocompatible than standard glucose solutions and those containing icodextrin. CONCLUSIONS: In our study the peritoneal dialysis solution containing carnitine seems to prevent the mesothelial changes observed with solutions containing glucose. Since carnitine has been extensively studied and seems to be well tolerated by hemodialysis patients, even at high doses for long periods, clinical trials in humans may be planned in the near future.

Animals↗
PubMed2005

Effect of solution composition of plasmid DNA on gene transfection following liver surface administration in mice.

We investigated the effect of plasmid DNA (pDNA) solution composition on gene transfection following liver surface administration in mice. Gene transfection experiments in situ and in vivo were performed using the following pDNA solutions: dextrose solution, NaCl solution, phosphate buffer, phosphate-buffered saline, Tris/HCl buffer with EDTA, Tris/HCl buffer with EDTA and Triton X-100, and water. In in situ experiments, we used a glass cylindrical diffusion cell that limited the contact area between the liver surface and the naked pDNA solution. The gene transfection at the site of diffusion cell attachment increased in hypotonic solution, and decreased in hypertonic solution, compared with isotonic solution. In in vivo experiments, instillation of naked pDNA solution onto the liver surface using a micropipette caused no significant differences in gene transfection in the applied lobe. These results suggest that it is important to select the optimal pDNA solution composition to control the gene transfection.

Administration, Topical↗
PubMed2005

Terahertz pulsed spectroscopy as a new tool for measuring the structuring effect of solutes on water.

Absorption spectra of aqueous solution of ''chaotropes'' (structure maker) and ''kosmotropes'' (structure breaker) have been recorded in the mid-infrared (MIR) and terahertz (THz) spectral region. A different impact of the two groups of solutes on the absorption spectrum of water was found in the recorded THz spectra. A concentration-dependent increased absorption across the investigated THz spectral region (0.04-2 THz, 1.3-66 cm(-1), respectively) has been recorded for all studied chaotropic solutions, whereas the opposite has been obtained for kosmotrope containing solutions. In the case of ionic solutes a further increase in absorption towards higher frequencies was measured. The distinction between chaotrope and kosmotrope solutes was, as expected, also possible in the MIR spectral region. Depending on the structure-forming effect of the solute the OH stretch vibration of the water (around 3400 cm(-1)) was slightly shifted. A red shift has been observed for solution of kosmotropes, whereas a blue shift was observed in the case of solutions containing chaotropes. Compared to the MIR spectral region the structure influencing effect of solutes can be more efficiently studied in the THz spectral region, which provides information from interactions between neighboring water molecules.

Complex Mixtures↗
PubMed2001

Peritoneal glucose exposure and changes in membrane solute transport with time on peritoneal dialysis.

Peritoneal solute transport increases with time on treatment in a proportion of peritoneal dialysis (PD) patients, contributing to ultrafiltration failure. Continuous exposure of the peritoneum to hypertonic glucose solutions results in morphologic damage that may have a causative role in changes in peritoneal function. The purpose of this analysis was to establish whether increased exposure to glucose preceded changes in solute transport in a selected group of long-term PD patients. Peritoneal solute transport, residual renal function, peritonitis rate, and peritoneal exposure to glucose were recorded prospectively in a cohort of 303 patients at a single dialysis center. A subgroup of individuals, treated continuously for 5 yr, were identified and defined retrospectively as having either stable or increasing transport status. Of the 22 patients who were treated continuously for 5 yr, 13 had stable solute transport (solute transport at start, 0.67 [+/-0.1]; at 5 yr, 0.67 [+/-0.1]), whereas 9 had a sustained increase (solute transport at start, 0.56 [+/-0.08]; at 5 yr, 0.77 [+/-0.09]). Compared with the stable patients, those with increasing transport had earlier loss in residual renal function and were exposed to significantly more hypertonic glucose during the first 2 yr of treatment that preceded the increase in solute transport. This was associated with greater achieved ultrafiltration compensating for the reduced urinary volumes in these patients. Further increases in glucose exposure were observed as solute transport continued to rise. Peritonitis, including severity of infection and causative organism, was similar in both groups. In this selected group of long-term survivors on PD, an increase in solute transport with time was preceded by increased peritoneal exposure to hypertonic glucose. This is supportive evidence that hypertonic glucose may play a causative role in alterations in peritoneal membrane function.

Adult↗
PubMed2006

Adaptation of the ion exchange method for the determination of the free ionic fraction of cadmium in solution.

The understanding of the availability of a metal in soil necessitates a minimum knowledge about its speciation in the soil solution. Here, we evaluated an alternative to the use of ion exchangers for estimating the free ionic fraction of cadmium (FCd) in solution. It is based on the exchange selectivity coefficient (VK) rather than the distribution coefficient (DK) to estimate FCd. Because VK for the Cd-Ca exchange for the used Amberlite resin was independent of the solution Ca concentration (0.5-7.5 mM) and pH (range: 4.5-6), the experiment on a solution mimicking the analyzed solution to estimate VK was not necessary. The influence of variable Ca and Mg concentrations in solution on FCd was assessed in synthetic solutions containing either citrate or malate. The best way to estimate FCd seemed to treat the exchange data as if Ca was solely present. However, neither the proposed approach nor those applying DK prevent the overestimation of FCd when Ca is partly complexed in the analyzed solution. A method intending to estimate two replicates of FCd for a given, unique solution was also studied on solutions issued from sorption-desorption experiments performed on a humic podzol. It consists of two successive supplies of a known resin mass to a unique sample. Both estimates were close and not significantly different.

Cadmium↗
PubMed1995

Brain edema and neurological status with rapid infusion of lactated Ringer's or 5% dextrose solution following head trauma.

Rapid infusion of 0.25 ml/g of 0.9% saline over 30 minutes has been shown to have no effect on electrolyte balance, neurological severity score (NSS), or brain edema, following closed head trauma (CHT). Rapid infusion of the same volume of 5% dextrose solution decreased blood sodium concentration, increased edema, and decreased NSS following CHT. In the present study the authors examined the effect of rapid infusion (30 minutes) of smaller volumes of 5% dextrose (0.08 ml/g and 0.16 ml/g) and of 0.25 ml/g lactated Ringer's solution on blood electrolyte concentrations, plasma osmolality, brain edema, and NSS. The purposes of this study were to determine whether rapid infusion of a large volume of lactated Ringer's solution could be given after CHT without increasing mortality or brain edema or producing electrolyte disturbances, and whether small volumes of 5% dextrose could be infused with few or none of the deleterious effects expected from large volumes of 5% dextrose. One hundred eighteen rats, which survived halothane anesthesia and CHT, were randomly assigned to one of 15 experimental groups. Fluids were administered beginning 1 hour after scalp incision or CHT. The NSS, extent of edema, blood electrolyte concentrations, and plasma osmolality in the groups treated with lactated Ringer's solution were not significantly different from those values in the nontreated groups. In addition, the mortality rate after CHT was not increased by administration of lactated Ringer's solution. The groups treated with 5% dextrose solution showed a significantly higher mortality rate, but the NSSs of the surviving rats were not different from controls. None of the groups treated with 0.16 ml/g 5% dextrose solution survived 24 hours. Although blood glucose concentration increased to 1126 +/- 102 g% (mean +/- standard deviation) and 1568 +/- 283 g% and blood sodium concentration decreased to 110.4 +/- 4.6 mEq/L and 92.0 +/- 5.2 mEq/L in the groups treated with 0.08 ml/g and 0.16 ml/g of 5% dextrose solution, respectively, plasma osmolality was normal and no significant difference could be found between the brain tissue specific gravity of animals in the nontreated and 5% dextrose treatment groups. It is concluded that in the CHT model used in this study, the large volume of lactated Ringer's solution did not affect blood electrolyte concentration, neurological outcome, or formation of brain edema, whereas smaller volumes of 5% dextrose solution increased blood glucose and decreased blood sodium concentrations, did not affect plasma osmolality, and had a deleterious effect on neurological outcome.

Animals↗
PubMed1999

Contractions in human detrusor smooth muscle induced by hypo-osmolar solutions.

PURPOSE: The aim of this study was to investigate stretch activated channels in human detrusor using hypo-osmolar solutions to produce cell deformation. Stretch activated channels could provide another mechanism by which detrusor myocytes may be coupled. MATERIALS AND METHODS: Human detrusor removed at surgery was dissected into strips and also enzymatically digested and cultured. Strips (5x1x1 mm.) were mounted in an organ bath and perfused with gassed Tyrode's. Hypo-osmolar solutions were made by removal of NaCl. Gadolinium (Gd3+), a blocker of stretch activated channels (SACs), and diltiazem, an L-type Ca2+ channel antagonist were used at 10 microM concentrations. Mean data +/- S.E.M. are expressed as a percentage of maximal tension produced by 1 microM carbachol for each patient. Enzymatically disaggregated, human detrusor was cultured in flasks, passaged and placed on glass coverslips. Once confluent the cells were incubated with the Ca2+ sensitive fluorochrome Fura-2AM. Coverslips were placed in a bath on the stage of EPI-fluorescence microscope and solutions were perfused through the bath (5 ml. per minute, 35C, pH 7.4). Changes in fluorescence emission ratio (proportional to changes in cytosolic Ca2+) were measured. RESULTS: Hypo-osmolar solutions produced a tension increase in the strips and a Ca2+ influx in the cells. In the strips in paired experiments Gd3+ and diltiazem significantly reduced the response to hypo-osmolar solution (87%+/-16% v. 51%+/-12.5%, p = 0.003, n = 10 for Gd3+), and (69%+/-11% v. 37%+/-9%, p = 0.001, n = 9 for diltiazem). In Ca2+ free solution responses were significantly reduced (65%+/-10% v. 21%+/-8%, p = 0.001, n = 9). In the cells in paired experiments, 10 microM Gd3+ significantly reduced the elevation of cytosolic Ca2+ in response to hypo-osmolar solutions (median 0 v. 0.38 (62 cells, n = 7 bladders)), as did Ca2+ free hypo-osmolar solution (median 0 v. 0.44 (46 cells, n = 7)). 10 microM diltiazem (L-type Ca2+ channel antagonist) did not influence the response to hypo-osmolar solution (p = 0.14, median 0.5 v. 0.54 (31 cells, n = 4)). CONCLUSIONS: Hypo-osmolar solutions produced a tension increase in human detrusor that appears to be dependent on upon influx of Ca2+ through stretch activated channels (SACs), influx of Ca2+ through L-type Ca2+ channels and also on release of intracellular Ca2+.

Calcium Channel Blockers↗
PubMed1999

A comparative study of the chemical stability of various mitomycin C solutions used in glaucoma filtering surgery.

OBJECTIVE: To determine the chemical stability of various mitomycin C (MMC) solutions used in glaucoma filtering surgery. METHODS: A survey of the MMC solutions currently in use in 21 hospitals (11 in Canada, 10 in the United States) was conducted. A comparative study of the chemical stability of five different representative solutions was performed. The effects of buffer and storage variables on the chemical breakdown of MMC in the solutions were studied by means of high-performance liquid chromatography (HPLC). RESULTS: The survey revealed 33 different variations (including recipes and storage conditions) in the preparation of MMC solutions. Although the majority of the hospitals (15 of 21; 72%) were preparing stable solutions, six of the hospitals (28%) were preparing potentially unstable solutions. The stability of the solutions varied in a nonuniform manner when stored at different temperatures in different buffers. CONCLUSION: The lack of standardization and quality control of MMC solutions used in filtering surgery allows for the possibility of hospitals preparing unstable solutions.

Buffers↗
PubMed2002

Effect of hypertonic saline solution on the left ventricular functions of isolated hearts from burned rats.

OBJECTIVE: To study the effect of hypertonic saline solution on the left ventricular functions of isolated hearts from burned rats. METHODS: Thirty-six Wistar rats were used and divided into 4 groups: (1) normal hearts perfused with isotonic Krebs-Henseleit solution; (2) normal hearts perfused with Krebs-Henseleit solution which contained 215 mmol/L Na+; (3) hearts of rats suffered from 25% TBSA third degree burn and perfused with isotonic Krebs-Henseleit solution; (4) hearts of the burned rats perfused with Krebs-Henseleit solution which contained 215 mmol/L Na+. The systolic and diastolic functions of the left ventricle were observed. RESULTS: During perfusion, there were very short periods of decrease in heart systolic and diastolic functions at first, but they recovered very soon and even became stronger than normal both in the normal and burned rats. The systolic and diastolic functions of the hearts increased very significantly when the perfusion solution was changed to isotonic solution from the hypertonic solutions. The effect of the hypertonic saline solution on the ventricular systolic and diastolic improvements was stronger in the hearts of the burned rats than that in the normal hearts. CONCLUSIONS: Hypertonic saline solution can directly affect myocardium and significantly improve the ventricular systolic and diastolic functions, especially in the hearts of the burned rats.

Animals↗
PubMed2002

[Effect of a dialysis solution with icodextrin on ultrafiltration and selected metabolic parameters in patients treated with peritoneal dialysis].

BACKGROUND: To date, peritoneal dialysis has been performed almost exclusively using dialysis solutions containing glucose as the osmotic agent. Use of these solutions is fraught with problems regarding adequate fluid removal from the body and is also associated with undesirable metabolic effects; hence the search for alternative osmotic agents. A dialysis solution with the glucose polymer icodextrin generates ultrafiltration on the principle of colloidal osmosis. The aim of the study was to establish the effect of icodextrin-base dialysis solution on the magnitude of ultrafiltration and evaluate selected metabolic parameters of patients treated by ambulatory peritoneal dialysis. METHODS AND RESULTS: A total of 9 patients whose glucose-based solution was replaced by an icodextrin-based solution during the night-time exchange were evaluated. A control group of 9 patients used glucose-solution during all exchanges. Night-time bag ultrafiltration, blood pressure, and the serum levels of lipids, insulin, leptin, maltose, and amylase were determined before icodextrin administration (time 0), at one-month intervals (time 1, 2, 3), and one month after study completion (time 4). In icodextrin-treated patients, ultrafiltration rose from 246.5 +/- 60.5 ml (mean +/- SEM) at time 0 to 593.1 +/- 87.4 ml; p < 0.01, at time 1, to 547 +/- 67 ml; p < 0.05, at time 2, and to 586.7 +/- 58.8 ml; p < 0.01, at time 3, the icodextrin administration led to a rise in maltose from 0.02 +/- 0.01 g/l at time 0 to 0.1 +/- 0.1 g/l; p < 0.01, at time 1, to 1.0 +/- 0.09 g/l; p < 0.01, at time 2, and to 1.1 +/- 0.09 g/l; p < 0.01, at time 3, with a fall to zero values at time 4 (NS). Icodextrin administration was followed by a decrease in leptinemia from 34.6 +/- 17.2 ng/ml at time 0 to 21.7 +/- 8.9 ng/ml; p < 0.05, at time 1, to 21.4 +/- 9.5 ng/ml; p < 0.05, at time 2, and to 15.9 +/- 24.1 ng/ml; p < 0.05 at time 4. Insulin and lipid levels were not affected. There was no change in the above parameters in the control group. Icodextrin-treated patients reduced their antihypertensive medication, but not statistically significantly. CONCLUSION: Icodextrin administration significantly increase ultrafiltration thus providing for effective control of hydration status without the need for high-level glucose-based dialysis solutions. The use of a glucose polymer-based dialysis solution is associated with a significant yet reversible rise in serum maltose. The decrease in leptin may signal a reduction in body weight after replacing glucose in dialysis solutions with icodextrin, or enhanced rates of leptin elimination as a result of ultrafiltration-induced convective transport.

Adult↗
PubMed2002

Volume osmotic flows of non-homogeneous electrolyte solutions through horizontally mounted membrane.

Results of an experimental study of volume osmotic flows in a single-membrane osmotic-diffusive cell, which contains a horizontal, microporous, symmetrical polymer membrane separating water and binary or ternary electrolyte solutions are presented. In the experimental set-up, water was placed on one side of the membrane. The opposite side of the membrane was exposed to binary or ternary solutions. As binary solutions, aqueous potassium chloride or ammonia solutions were used, whereas potassium chloride in 0.25 mol x l(-1) aqueous ammonia solution or ammonia in 0.1 mol x l(-1) aqueous potassium chloride solution were used as ternary solutions. Two (A and B) configurations of a single-membrane osmotic-diffusive cell in a gravitational field were studied. In configuration A, water was placed in a compartment above the membrane and the solution below the membrane. In configuration B the position of water and solution was reversed. Furthermore, the effect of amplification of volume osmotic flows of electrolyte solutions in the single-membrane osmotic-diffusive electrochemical cell was demonstrated. The thermodynamic models of the flux graviosmotic and amplification effects were developed, and the volume flux graviosmotic effect for configurations A and B of a single-membrane osmotic-diffusive cell was calculated. The results were interpreted within the conventional instability category, increasing the diffusion permeability coefficient value for the system: concentration boundary layer/membrane/concentration boundary layer.

Ammonia↗