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PubMed1991

St. Thomas' Hospital cardioplegic solution. Beneficial effect of glucose and multidose reinfusions of cardioplegic solution.

The intention of this study was to determine whether glucose is beneficial in a cardioplegic solution when the end products of metabolism produced during the ischemic period are intermittently removed. The experimental model used was the isolated working rat heart, with a 3-hour hypothermic 10 degrees C cardioplegic arrest period. Cardioplegic solutions tested were the St. Thomas' Hospital No. 2 and a modified Krebs-Henseleit cardioplegic solution. Glucose (11 mmol/L) was beneficial when multidose cardioplegia was administered every 30 minutes. Including glucose in Krebs-Henseleit cardioplegic solution improved postischemic recovery of aortic output from 57.0% +/- 1.8% to 65.8% +/- 2.2%; p less than 0.025. The addition of glucose to St. Thomas' Hospital No. 2 cardioplegic solution improved aortic output from 74.6% +/- 1.9% to 87.4% +/- 1.9%; p less than 0.005. Furthermore, a dose-response curve showed that a glucose concentration of 20 mmol/L gave no better recovery than 0 mmol/L, and glucose in St. Thomas Hospital No. 2 cardioplegic solution was beneficial only in the range of 7 to 11 mmol/L. In addition, we showed that multidose cardioplegia was beneficial independent of glucose. Multidose St. Thomas' Hospital No. 2 cardioplegia, as opposed to single-dose cardioplegia, improved aortic output recovery from 57.4% +/- 5.2% to 74.6% +/- 1.9%; p less than 0.025, and with St. Thomas' Hospital No. 2 cardioplegic solution plus glucose (11 mmol/L) aortic output recovery improved from 65.9% +/- 2.9% to 87.4% +/- 1.9%; p less than 0.005. Hence, at least in this screening model, the St. Thomas' Hospital cardioplegic solution should contain glucose in the range of 7 mmol/L to 11 mmol/L, provided multidose cardioplegia is given. We cautiously suggest extrapolation to the human heart, on the basis of supporting clinical arguments that appear general enough to apply to both rat and human metabolisms.

Animals↗

PubMed1988

Head injury and hemorrhagic shock: studies of the blood brain barrier and intracranial pressure after resuscitation with normal saline solution, 3% saline solution, and dextran-40.

The effect of fluid resuscitation from hemorrhagic shock on cerebral edema, intracranial pressure (ICP), and blood brain barrier function was investigated in the presence of a simulated head injury. Beagle dogs were anesthetized and ICP was measured via a right subarachnoid bolt while a contralateral epidural balloon was inflated in the left hemicranium to mimic a closed head injury. Forty percent of the dogs' blood was shed and the shock state was maintained for 1 hour. Resuscitation was initiated with shed blood and a volume of either normal saline solution (NS, n = 5), 10% dextran-40 (D-40, n = 6), or hypertonic (3%) saline solution (HS, n = 6) equal to the amount of shed blood. Evans blue solution was infused intravenously, and intravascular volume was then maintained with normal saline solution. Control (n = 5) dogs did not undergo shock, but received equivalent volumes of normal saline solution and Evans blue solution. The dogs were killed after 2 hours of resuscitation, and the brains were removed, weighed, and fixed in formalin. The average intracranial pressure value after epidural balloon inflation was 18.6 +/- 0.80 mm Hg and decreased equally in all groups during the shock period, averaging 10.8 +/- 1.24 mm Hg at the end of the shock period. Fluid resuscitation markedly elevated ICP in the NS and D-40 groups, reaching maximal values of 46.6 +/- 12.11 mm Hg and 45.3 +/- 28.95 mm Hg, respectively. Maximal ICP values in control and HS groups measured 21.8 +/- 1.36 mm Hg and 15.8 +/- 2.04 mm Hg, respectively (p less than 0.25 for HS versus NS control). Wet brain weights were significantly less in the HS group compared with either NS or D-40 groups (p less than 0.05). Coronal sections of fixed HS brains showed deep cortical Evans blue staining on the side of balloon injury. Therefore, in the presence of an intracranial mass lesion, resuscitation with hypertonic (3%) saline solution is accompanied by lower ICP values and less cerebral edema than is isotonic saline or colloid resuscitation. Blood brain barrier function is not restored by hypertonic saline solution resuscitation.

Animals↗

PubMed1987

Studies on the physical state of water in living cells and model systems. VI. Concentration-dependent sustained volume changes of dialysis sacs containing aqueous solution of native and denatured protein, gelatin, and oxygen-containing polymers immersed in solutions of Na salt and of sugar and sugar alcohol.

In this paper we studied the volume changes of dialysis sacs containing concentrated solutions of native and denatured proteins and of oxygen-containing polymers after immersion in aqueous solution of Na-citrate, D-glucose, and sorbitol of varying concentration. The results confirm the theory of cell volume regulation: volume changes of living cells in different solutions represent a balance between the tendency of intracellular proteins -- which exist in the fully extended conformation -- to polarize, sorb, and draw into the sac or cell more water and the opposite tendency to lose water from the sac or cell created by the lower level of the solutes in the cell or sac water than in the external medium. The lower level of the solutes is the consequence of the reduced solvency of the polarized water in the sac or cell water for large and complex solutes like sugar and free amino acids. This study adds another important physico-chemical attribute of the living cell that can be duplicated by aqueous solutions of gelatin, oxygen-containing polymers like PEO and PEG as well as urea-denatured proteins but not, or only weakly so, by aqueous solutions of native proteins or SDS-denatured proteins.

Animals↗

PubMed2000

Human albumin solution for resuscitation and volume expansion in critically ill patients. The Albumin Reviewers.

BACKGROUND: Human albumin solutions are used in a range of medical and surgical problems. Licensed indications are the emergency treatment of shock and other conditions where restoration of blood volume is urgent, burns, and hypoproteinaemia. Human albumin solutions are more expensive than other colloids and crystalloids. OBJECTIVES: To quantify the effect on mortality of human albumin and plasma protein fraction (PPF) administration in the management of critically ill patients. SEARCH STRATEGY: We searched the Cochrane Injuries Group trials register, Cochrane Controlled Trials Register, Medline, Embase and BIDS Index to Scientific and Technical Proceedings. Reference lists of trials and review articles were checked, and authors of identified trials were contacted. The search was last updated in November 1999. SELECTION CRITERIA: Randomised controlled trials comparing albumin/PPF with no albumin/PPF, or with a crystalloid solution, in critically ill patients with hypovolaemia, burns or hypoalbuminaemia. DATA COLLECTION AND ANALYSIS: We collected data on the participants, albumin solution used, mortality at the end of follow up, and quality of allocation concealment. Analysis was stratified according to patient type. We assessed publication bias using the regression test for funnel plot asymmetry. MAIN RESULTS: We found 30 trials meeting the inclusion criteria and reporting death as an outcome. There were 156 deaths among 1419 trial participants. For each patient category the risk of death in the albumin treated group was higher than in the comparison group. For hypovolaemia the relative risk of death following albumin administration was 1.46 (95% confidence interval 0.97 to 2.22), for burns the relative risk was 2.40 (1.11 to 5.19), and for hypoalbuminaemia the relative risk was 1.69 (1.07 to 2.67). The pooled relative risk of death with albumin administration was 1.68 (1.26 to 2.23). Overall, the risk of death in patients receiving albumin was 14% compared to 8% in the control groups, an increase in the risk of death of 6% (3% to 9%). These data suggest that for every 17 critically ill patients treated with albumin there is one additional death. REVIEWER'S CONCLUSIONS: There is no evidence that albumin administration reduces the risk of death in critically ill patients with hypovolaemia, burns or hypoalbuminaemia, and a strong suggestion that it may increase the risk of death. These data suggest that the use of human albumin in critically ill patients should be urgently reviewed and that it should not be used outside the context of a rigorously conducted randomised controlled trial.

Blood Proteins↗

PubMed2000

Diffusion Coefficients of Three Organic Solutes in Aqueous Sodium Dodecyl Sulfate Solutions.

Tracer diffusion coefficients of phenol, toluene, and benzoic acid in aqueous solutions of sodium dodecyl sulfate (SDS) were measured by the Taylor dispersion technique. In addition, the viscosities and densities of the SDS solutions were measured. For phenol and toluene, the effect of micelle formation on the diffusion coefficient is pronounced. When the SDS concentration is below the critical micelle concentration (cmc), the diffusion coefficients are almost independent of the SDS concentration. However, above the cmc there is a rapid decrease in the diffusion coefficients, and the apparent diffusion coefficients of the two solutes are the weighted average of free solute diffusion and the micelle diffusion. A model is presented to describe the diffusion behavior of the two solutes in aqueous micellar solutions of SDS. The interaction between the two solutes and the micelles has been investigated and the fraction of each solute that is solubilized by the micelles is estimated from the measured apparent diffusion coefficient. For benzoic acid, the diffusion coefficient is dependent on the joint contribution of the benzoic acid molecules that are solubilized by the micelles as well as the corresponding benzoate ions. The effect of micelle formation on the diffusion coefficient of benzoic acid is not as pronounced as for phenol and toluene. Copyright 2000 Academic Press.

Journal Article↗

PubMed1979

Thermochemistry of aqueous solutions of alkylated nucleic acid bases. II. Apparent molar relative enthalpies of dilution of solutions containing uracil and thymine derivatives.

Apparent molar relative enthalpies of dilution phi(L)of aqueous solutions of a series of alkylated diketopyrimidines: m(1)Ura, m(1,3)(2)Ura, m(1,3)(2)Thy, m(1,3,6)(3)Ura and e(1,3)(2)Thy were measured as a function of concentration of the solutes at three temperatures 298.15, 308.15 and 318.15 K. Dilution proved to be an endothermic process over the whole range of molalities m and temperatures studied for all compounds except the e(1,3)(2)Thy solution, the dilution of which, with the exception of the lowest concentrations (m > 0.2-0.3) was an exothermic process. Partial molar relative enthalpies of dilution -L(2)(m) derived from phi(L)(m) functions were analysed as if they were composed of two additive contributions: an endothermic one -L(2), (m(1)) and an exothermic one 1.2, (m(as)0), owing to the presence in the solutions of a free monomer m(1) or associated species m(as), respectively. Partial molar heat capacities of the solutes, evaluated by differentiation of -L(2)(m) functions in respect to temperature, decreased with the rise of concentration in the order of the tendency of the solutes to stacking association. Changes in heat content and in heat capacity of solutions upon their dilution are interpreted in terms of involvement of hydrophobic hydration and association of the solutes.

Journal Article↗

PubMed2005

Effect of "inverse melting transition" of aqueous triblock copolymer solutions on solute rotational dynamics.

Rotational dynamics of two structurally similar hydrophobic solutes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and 1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DPP), has been investigated in 30% wv aqueous solution of triblock copolymer, poly(ethylene oxide)(20)-poly(propylene oxide)(70)-poly(ethylene oxide)(20) as a function of temperature. This study has been undertaken in an attempt to explore how the dynamics of a solute molecule solubilized in a copolymer solution is influenced when it undergoes sol-to-gel transition. It has been observed that the anisotropy decays of both DMDPP and DPP can be described by biexponential functions in the sol as well as in the gel phase. This observation has been rationalized on the basis of the probe molecule undergoing two different kinds of motion rather than being located in two different regions of the micelle. Even in the gel phase, which results as a consequence of micelle-micelle entanglement due to an increase in their volume fraction, the rotational relaxation of the solutes is similar to that observed in the micellar solution. The outcome of this work indicates that even though these gels have very high macroscopic viscosities and hence do not flow, the microenvironments experienced by the solutes are akin to that of a micellar solution.

Journal Article↗

PubMed2004

Potential of far-ultraviolet absorption spectroscopy as a highly sensitive quantitative and qualitative analysis method for aqueous solutions, part I: determination of hydrogen chloride in aqueous solutions.

This paper reports the usefulness of far-ultraviolet (FUV) absorption spectroscopy in highly sensitive quantitative and qualitative analysis of aqueous solutions. We propose a totally new idea for the utilization of FUV spectroscopy in pure water and aqueous solution analyses. We use an absorption band near 170 nm due to an n --> sigma* transition of water. The intensity of the foot of this band, which can be observed in the 190-210 nm region by use of an ordinary ultraviolet-visible (UV-Vis) spectrometer, is very sensitive to changes in hydration and hydrogen bonds of water. To demonstrate the potential of FUV spectroscopy in analytical chemistry, we undertook three kinds of experiments. The first one is concerned with the discrimination of eight kinds of commercial natural mineral water. The eight kinds of mineral water can be discriminated straightforwardly from the spectral patterns in the 190-250 nm region without any spectral pretreatment or spectral analysis such as multivariate analysis. The second experiment is the determination of hydrogen chloride (HCl) in aqueous solutions. FUV spectra of aqueous solutions of HCl over a concentration of 0-20 ppm were measured. A calibration model for predicting the concentration of HCl in the aqueous solutions was developed based on the absorbance at 193 nm. This method does not require any spectral pretreatment or multivariate analysis. The correlation coefficient and standard error of prediction of the calibration model developed are 0.9987 and 0.18 ppm, respectively. The detection limit of the proposal method for the determination of HCl in aqueous solutions was estimated to be 0.5 ppm (13.7 microM). The determination of HCl was also tried for natural mineral water to which HCl solutions with the concentrations of 2, 4, 6, 8, 12, 16, and 20 ppm were artificially added. The third study was the determination of ammonia (NH3) and hydrogen peroxide (H2O2) in aqueous solutions containing both NH3 and H2O2. It has been found that the present method is also useful for the determination of the two-component system.

Hydrochloric Acid↗

PubMed2005

Epidural migration of new methylene blue in 0.9% sodium chloride solution or 2% mepivacaine solution following injection into the first intercoccygeal space in foal cadavers and anesthetized foals undergoing laparoscopy.

OBJECTIVE: To determine the relationship between epidural cranial migration and injectate volume of an isotonic solution containing dye in laterally recumbent foal cadavers and evaluate the cranial migration and dermatome analgesia of an epidural dye solution during conditions of laparoscopy in foals. ANIMALS: 19 foal cadavers and 8 pony foals. PROCEDURES: Foal cadavers received an epidural injection of dye solution (0.05, 0.1, 0.15, or 0.2 mL/kg) containing 1.2 mg of new methylene blue (NMB)/mL of saline (0.9% NaCl) solution. Length of the dye column and number of intervertebral spaces cranial and caudal to the injection site were measured. Anesthetized foals received an epidural injection of dye solution (0.2 mL/kg) containing saline solution or 2% mepivacaine. Foals were placed in a 100 head-down position, and pneumoperitoneum was induced. Dermatome analgesia was determined by use of a described electrical stimulus technique. Foals were euthanatized, and length of the dye column was measured. RESULTS: Epidural cranial migration of dye solution in foal cadavers increased with increasing volume injected. No significant difference was found in epidural cranial migration of a dye solution (0.2 mL/kg) between anesthetized foals undergoing conditions of laparoscopy and foal cadavers in lateral recumbency. Further craniad migration of the dye column occurred than indicated by dermatome analgesia. CONCLUSIONS AND CLINICAL RELEVANCE: Epidural cranial migration increases with volume of injectate. On the basis of dermatome analgesia, an epidural injection of 2% mepivacaine (0.2 mL/kg) alone provides analgesia up to at least the caudal thoracic dermatome and could permit caudal laparoscopic surgical procedures in foals.

Anesthesia, Epidural↗

PubMed1989

Absorption of water and solute from glucose-electrolyte solutions in the human jejunum: effect of citrate or betaine.

The inclusion in oral rehydration solutions of solutes that are actively co-transported with sodium has been suggested as a means of increasing the effect of glucose on water absorption by the small intestine. Using a modified perfusion system we have examined water and solute absorption in the normal human intestine from two effervescent glucose-electrolyte solutions, containing either citrate or betaine hydrochloride, and compared the absorption rates with those from a commonly used bicarbonate-containing oral rehydration solution. Absorption of citrate (355 +/- 87 mumol/cm/h) and betaine (313 +/- 125 mumol/cm/h) occurred from the respective solutions. The inclusion of 46 mmol/l citrate or 36 mmol/l betaine in effervescent oral rehydration solutions had no effect on water or solute absorption.

Betaine↗

PubMed1998

Use of Amuchina 50% solution versus povidone-iodine 10% solution for transfer-set change in peritoneal dialysis patients.

The goal of this study was to compare the safety and efficacy of Amuchina 50% solution versus that of povidone-iodine 10% solution for transfer-set change in peritoneal dialysis (PD) patients in a tertiary referral university hospital. The transfer sets were changed using povidone-iodine 10% solution as disinfectant prior to March 1995. Thereafter Amuchina 50% solution was used. Thus data were collected on all the transfer sets changed between January 1993 and August 1997. Amuchina is an electrolytic chloroxidizer. Chlorine is the active ingredient with a pH of 9.5-10.5. Amuchina 50% solution contains chlorine (0.55%). One hundred ninety-nine transfer sets were changed using povidone-iodine 10% solution in 60 PD patients from January 1993 to March 1995. One hundred twenty-eight transfer sets were changed using Amuchina 50% solution in 65 patients from April 1995 to August 1997. The soaking times and nursing times were 2 and 5 minutes, respectively, with Amuchina, and 10 and 20 minutes, respectively, with povidone-iodine 10%. No episode of peritonitis occurred related to transfer-set change in either group. The transfer-set change using Amuchina 50% solution is safe and cost-effective in PD patients.

Anti-Infective Agents, Local↗

PubMed2000

Retention of problem solutions: the re-solution effect.

Four experiments compared the re-solution performance of prior solvers with that of prior nonsolvers given the correct solutions. Experiments 1 and 2 challenged Weisberg and Alba's (1981) contention that solving a problem and being shown the solution yield equivalent problem knowledge. In both experiments, students who initially solved problems showed near-perfect recall of the solutions after a 1-week delay, far superior to recall by students who had been shown the correct answers. In Experiment 3, solves showed poor solution retention when the connection between the problem and the solution was not meaningful. Experiment 4 showed that with meaningful problems, solvers and those merely provided with solutions have qualitatively different problem representations. The findings can be explained in terms of differential understanding of problems and their solutions.

Humans↗

PubMed1988

[Effect of a 10% and 6% hydroxyethyl starch solution (molecular weight 200,000/0.62) in comparison with a 10% dextran solution (molecular weight 40,000) on flow properties of blood and tissue oxygen pressure in patients with intermittent claudication].

In a randomized, double-blind cross-over study in 10 patients with intermittent claudication, 2 concentrations (6% and 10%) of a hydroxyethyl starch (HES) solution of mean molecular weight 200,000 and of substitution degree 0.62 were compared to a 10% low-molecular-weight dextran solution of mean molecular weight 400,000. In addition to several hemorheological parameters, the behavior of the tissue oxygen pressure directly in the ischemic lower leg muscles of patients with chronic arterial occlusive vascular disease (stage IIb) was examined. 500 ml of the solutions described above were infused over a period of 30 min. Parameters such as tissue oxygen pressure and flow properties of blood were determined before infusion, immediately upon terminating infusion and 30, 60, 90, 120 and 180 min thereafter. A reduction of hematocrit values and of whole blood viscosity was observed, which was most pronounced with the 10% solutions. The plasma viscosity increased significantly with both the 10% dextran solution as well as with the 10% HES solution. This behavior was less pronounced with the 6% solution. Measurement of the erythrocyte aggregation yielded an increase in values after infusion which was more significant for the 10% than for the 6% HES solution. The tissue oxygen pressure, as a measure of the tissue oxygen supply, remained more or less constant during hypervolemic hemodilution, despite reduced hematocrit values in the dextran group and in the 10% HES group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed2004

Proabsorptive effect of gum arabic in isotonic solutions orally administered to rats: effect on zinc and other solutes.

We have previously shown that the addition of gum arabic (GA) to oral rehydration solution (ORS) enhances water and electrolyte absorption during jejunal perfusion in rats under anesthesia. This study investigates whether GA by oral administration could be equally effective in rats. Isotonic solutions containing 25 g/L GA (AG), or without GA (A0) were administered via oral tube to lightly anesthetized adult female rats. Similar experiments were conducted with hypertonic solutions containing no GA (B0), or either 10 (B10) or 50 g/L GA (B50). Blood concentrations of sodium, glucose, glutamate, zinc, and tritiated water were determined at 0, 15, 30, 60, 90, 120, and 180 minutes, and results between treatments were compared. Administration of the isotonic, GA-containing solution (AG) resulted in a higher blood zinc level than with the isotonic GA-free solution (A0) from 15 minutes throughout 180 minutes. Blood zinc at 15 minutes (means +/- SEM) was as follows: for A0: 69.3 +/- 2.0, for AG: 83.4 +/- 3.5 nmol/L, P=0.002. At 180 minutes, A0: 52.6 +/- 1.8; AG: 68.1 +/- 4.6 nmol/L, P=0.004. The corresponding areas under the curve (AUC) were as follows: for A0: 10,737 +/- 214; for AG: 13,919 +/- 765 nmol x min/L, P<0.001). Glucose, glutamate, sodium, and tritiated water body distribution presented no differences in blood concentrations. For sodium and tritiated water body distribution, there was a significant time effect (P<0.0001). In hypertonic solutions, blood zinc levels declined over time, possibly due to their osmotic, counter-absorptive action, thus obscuring possible opposite effects of GA. GA appears to be an effective enhancer of zinc absorption when orally administered in isotonic solutions to laboratory animals. This proabsorptive capacity could be attributed to some of the physicochemical and biochemical properties of GA and suggest possible applications of GA in liquid formulas and solid food preparations.

Absorption↗

PubMedDate not supplied

A clinical trial comparing University of Wisconsin solution and cold cardioplegic solution with load-independent mechanical parameters.

To evaluate the efficacy of University of Wisconsin solution for clinical heart transplantation, load-independent parameters were used to assess left ventricular function after transplantation. Donor hearts were arrested with and stored in buffered cold cardioplegic solution for control (n = 5) and University of Wisconsin solution for the experimental group (n = 5). Orthotopic transplantations were performed in a routine manner. Mean donor age (cardioplegic solution, 28 +/- 5.2 years; University of Wisconsin solution, 28 +/- 5.1 years) and ischemic times (cardioplegic solution, 181 +/- 27 minutes; University of Wisconsin solution, 224 +/- 23 minutes) were similar. Two hours after reperfusion of the heart, transesophageal echocardiography was used to image the left ventricle at the mid-papillary muscle level, and a high-fidelity catheter-tipped manometer was placed in the left ventricle to record left ventricular pressure simultaneously. These images were digitized during apneic baseline conditions and during an acute reduction in preload from inferior vena caval occlusion. The left ventricular cross-sectional areas were measured and matched with left ventricular pressure from the catheter-tipped manometer to reveal pressure-area relationships. The baseline parameters fractional area change and stroke force were calculated. End-systolic elastance, the slope of end-systolic pressure-area relationship and preload recruitable stroke force, the slope of stroke force versus end-diastolic area were calculated from the inferior vena cava occlusion measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

PubMed1990

Rat liver preservation. II. Combining UW solution with Eurocollins solution or Ringer's lactate abrogates its protective effect.

The mechanisms by which cold preservation solutions exert their protective effects are only partially understood. The consequences of mixing different solutions, with presumably different modes of action, may be additive and beneficial or may be deleterious. It is commonplace in clinical liver preservation to use Ringer's lactate (RL), Eurocollins (EC), and University of Wisconsin (UW) solution in sequence for washout of blood, precooling, and cold storage of the organ. In this study, 114 Sprague Dawley rats received orthotopic liver transplants that were flushed in various sequences with RL, EC, and UW solutions. One-week animal survival served as the criterion of preservation success. The results demonstrated that liver preservation with UW solution alone is significantly superior (P less than 0.01) to any combination of RL, EC, and UW solutions and may explain some of the instances of primary nonfunction in clinical liver transplantation.

Adenosine↗

PubMed1990

Cardioplegia for transplantation: failure of extracellular solution compared with Stanford or UW solution.

Crystalloid cardioplegia with an extracellular fluid formulation is widely used for donor heart protection. A survey of 109 transplant programs yielded 62 replies with 42% of respondents using variations of extracellular solution and 45% using the dextrose and mannitol-based Stanford solution. These two commonly used clinical solutions and University of Wisconsin (UW) solution, which has had success in clinical hepatic and renal transplantation, were compared in a canine model of cardiac transplantation. After antegrade hypothermic cardioplegic arrest, the experimental hearts were excised and stored at 4 degrees C for 6 hours (n = 29). An oxygenated, blood-primed isolated heart preparation was used for reperfusion. After a rest of 45 minutes, cardiac output was increased against constant afterload until a left atrial pressure of 15 mm Hg was reached. The maximum cardiac performance measured by cardiac index, minute work, and stroke work was highly significantly better with Stanford or UW solution protection than with the extracellular solutions (p less than 0.0001). Assuming a cardiac index of 50 mL.kg-1.min-1 is necessary for successful separation from cardiopulmonary bypass, only 1 of 14 extracellular and 15 of 15 Stanford and UW animals would have survived (p less than 0.0001). This study strongly suggests that extracellular cardioplegia is inferior for cardiac transplantation and that programs using this solution should reevaluate their method of myocardial protection for donor hearts.

Animals↗

PubMed1973

Dilute solution approximation and generalization of the reflection coefficient method of describing volume and solute flows.

Kedem and Katchalsky introduced an approximation for dilute solutions which requires that the quantity (Deltapi/Deltapi(i))ø(i) be much less than one. Zelman attempted to generalize the reflection coefficient concept to apply to solutions of multiple solutes, both penetrable and impenetrable, of concentrations sufficiently high for the approximation not to work. By simple algebraic manipulation, Zelman introduced a pair of new reflection coefficients, and a third new parameter gamma which he misleadingly calls the "deviation from the dilute solution approximation." It is shown here that the original Kedem-Katchalsky form for the flow equations can be preserved in such a way that no new coefficients need be introduced and an explicit statement of the effect of the dilute solution approximation can be made. There is an option of using a new set of conjugate driving forces for the solute flows or, alternatively, incorporating the nondilute solution correction in the coefficients in a clear way.

Biological Transport↗