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PubMed1990

Prolonged cardiac preservation. Evaluation of the University of Wisconsin preservation solution by comparison with the St. Thomas' Hospital cardioplegic solutions in the rat.

The University of Wisconsin solution differs from other types of solutions used for organ preservation because it contains high-energy phosphate precursors (adenosine and phosphate), impermeants (lactobionate and raffinose), an oncotic agent (pentafraction), and antioxidants (allopurinol and glutathione). These components have the potential to enhance the preservation of ATP, reduce intracellular and extracellular edema, and attenuate free-radical-mediated injury. The University of Wisconsin solution has been demonstrated to enhance and extend the preservation of the liver, pancreas, and kidney, but its potential role in the heart remains unproven. We have evaluated the University of Wisconsin solution (Du Pont) by comparing it with the St. Thomas' Hospital cardioplegic solutions No. 1 and No. 2 (Plegisol), which are used in Europe and the United States for routine cardiac surgery and transplantation. For each solution, 10 isolated working rat hearts were arrested by 10 ml of the solution (at 4 degrees C) and then maintained immersed in the same solution for 4 hours at 4 degrees C. Mean recovery of functional indexes (expressed as a percentage of their preischemic control values) after use of the University of Wisconsin solution were as follows: peak aortic pressure, 90.6 +/- 1.0; dP/dt, 71.5 +/- 5.5; aortic flow, 81.6 +/- 4.7; coronary flow, 87.5 +/- 3.5; and cardiac output, 82.6 +/- 3.5. In contrast, the mean recoveries after St. Thomas' Hospital solution No. 1 were as follows: peak aortic pressure, 82.8 +/- 1.3; dP/dt, 49.7 +/- 3.0; aortic flow, 58.4 +/- 5.3; coronary flow, 79.6 +/- 5.9; and cardiac output, 63.0 +/- 4.9. In contrast still, mean recoveries after St. Thomas' Hospital solution No. 2 were as follows: peak aortic pressure, 83.1 +/- 1.2; dP/dt, 40.7 +/- 6.1; aortic flow, 37.0 +/- 5.1; coronary flow, 65.8 +/- 3.6; and cardiac output, 43.1 +/- 5.6. The recovery of all indexes were significantly superior (p less than 0.005) after preservation with University of Wisconsin solution compared with either of the St. Thomas' Hospital solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed2004

Bowel preparation for colonoscopy: a randomized controlled trial comparing polyethylene glycol solution, one dose and two doses of oral sodium phosphate solution.

OBJECTIVES: To compare three bowel preparation regimens for colonoscopy in terms of the quality of preparation, the side effects and patient acceptance. METHODS: A total of 299 patients who underwent colonoscopy were randomized to three bowel preparation regimens: polyethylene glycol solution (n = 106), or a single dose (n = 92) or two doses (n = 101) of sodium phosphate solution. The colonoscopists who recorded the quality of bowel preparation were blind to the preparation regimens. The discomforts associated with bowel preparation and patient acceptance of the preparation were also recorded. RESULTS: Two doses of sodium phosphate solution achieved significantly better bowel preparation than polyethylene solution or a single dose of sodium phosphate solution (p < 0.05). Although two doses of sodium phosphate solution was associated with more dizziness and anal irritation, patients preferred preparation with sodium phosphate solution than with polyethylene glycol solution. Of the 69 patients in the sodium phosphate solution groups who had prior experience of bowel preparation using polyethylene glycol solution, 55 patients (80%) stated that they preferred sodium phosphate solution. CONCLUSION: Two doses of sodium phosphate solution achieved better bowel preparation than polyethylene glycol solution and was more acceptable to patients. A single dose of sodium phosphate did not achieve similar bowel preparation to two doses of the solution.

Adult↗
PubMed1992

Water and solute absorption from a new hypotonic oral rehydration solution: evaluation in human and animal perfusion models.

Controversy continues regarding the optimal composition of glucose electrolyte oral rehydration solutions for the treatment of acute diarrhoea. Four perfusion models (normal human jejunum, normal rat small intestine, cholera toxin treated secreting rat small intestine and rotavirus infected rat small intestine) have been developed and used to compare the efficacy of a hypotonic oral rehydration solution with standard United Kingdom British National formulary and developing world oral rehydration solutions (WHO). Despite obvious physiological and pathophysiological differences between these models there was general congruence in the water and solute absorption profiles of the different oral rehydration solutions. Hypotonic oral rehydration solution promoted significantly greater water absorption than other oral rehydration solutions in all rat models (p < 0.001) but apparently increased water absorption failed to achieve significance in human jejunum. British National Formulary-oral rehydration solution was unable to reverse net water secretion in both rotavirus and cholera toxin models. Net sodium absorption from hypotonic and WHO-oral rehydration solutions was significantly greater than from the low sodium British National Formulary-oral rehydration solutions (p < 0.001) except in the rotavirus model when absorption was similar to hypotonic-oral rehydration solutions. These findings show that there is agreement in the apparent efficacy of oral rehydration solutions in these animal and human perfusion models, and that improved water absorption with adequate sodium absorption may be achieved by reducing oral rehydration solution osmolality.

Adolescent↗
PubMed2001

Superior 12-hour heart preservation with pinacidil hyperpolarizing solution compared to University of Wisconsin solution.

BACKGROUND: novel donor heart preservation solution was formulated to produce hyperpolarized arrest with the potassium channel opener, pinacidil. The superior cardioprotective efficacy of this solution has been demonstrated previously when compared to University of Wisconsin solution following 4 hours of hypothermic ischemia. This study tested the hypothesis that pinacidil solution may extend preservation time and provide superior cardioprotective efficacy following 12 hours of ischemia. METHODS: Sixteen rabbit hearts were assigned to receive either pinacidil solution or University of Wisconsin solution in a crystalloid-perfused Langendorff model. Thirty minutes of initial perfusion preceded baseline data acquisition. Left ventricle pressure-volume curves were generated by inflating an intra-ventricular latex balloon. Following cardioplegic administration, hearts underwent 12 hours of hypothermic storage. After 60 minutes of reperfusion, post-ischemic data were acquired. RESULTS: Pinacidil solution demonstrated significantly better myocardial preservation compared to University of Wisconsin solution, with better recovery of developed pressure (53.0 +/- 11.1% vs 20.7 +/- 4.3%, p = 0.017, respectively), post-ischemic coronary flow (55.3 +/- 12.6% vs 23.9 +/- 4.3%, p = 0.034), maximum systolic dP/dT (46.4 +/- 8.3% vs 20.2 +/- 5.1%, p = 0.018) and minimum diastolic -dP/dT (65.3 +/- 10.8% vs 20.2 +/- 5.1%, p = 0.002). Diastolic compliance, expressed as baseline/post-ischemic diastolic slope ratios, was also better preserved by pinacidil solution (0.55 +/- 0.09) vs University of Wisconsin solution (0.40 +/- 0.03) (p = 0.135). CONCLUSIONS: A novel pinacidil solution resulted in improved donor heart preservation during 12 hours of hypothermic ischemia compared to the "gold standard," University of Wisconsin solution. Adopting alternative strategies of hyperpolarized arrest may allow extension of preservation time beyond the limits of traditional depolarizing solutions.

Animals↗
PubMedDate not supplied

A comparison of UW cold storage solution and St. Thomas' solution II: a 31P NMR and functional study of isolated porcine hearts.

Although University of Wisconsin cold storage solution provides excellent preservation for the pancreas, the kidney, and the liver after extended cold ischemic storage, its ability to preserve the heart for extended cold storage periods is not yet proved. This study was carried out to evaluate the effect of University of Wisconsin solution on heart preservation and to compare it to modified St. Thomas' solution II with respect to the capacity to preserve high-energy phosphates and contractile function in pig hearts. Hearts were arrested with either University of Wisconsin cold storage solution or St. Thomas' solution II (10 ml/kg) and kept ischemic at 12 degrees C or 4 degrees C for 8 hours. Functional recovery after the preservation period was assessed by means of ventricular function curves of the isovolumically contracting Langendorff model perfused with modified Krebs-Henseleit solution. Phosphorus 31 nuclear magnetic resonance spectroscopy was used to monitor high-energy phosphates and intracellular pH during preservation and reperfusion. At 12 degrees C, hearts arrested and preserved with University of Wisconsin solution showed a rapid decrease in phosphocreatine and adenosine triphosphate. With St. Thomas' solution, phosphocreatine and adenosine triphosphate decreased slowly. Functional recovery was poorer with University of Wisconsin solution than with St. Thomas' solution. Hearts preserved at 4 degrees C with either solution showed no significant differences in high-energy phosphate content and functional recovery. Rigorous control of the low temperature (4 degrees C) is necessary when University of Wisconsin solution is used for heart preservation.

Adenosine↗
PubMed2001

Absorption of 193- and 213-nm laser wavelengths in sodium chloride solution and balanced salt solution.

OBJECTIVE: To determine absorption coefficients for sodium chloride solution (saline) and balanced salt solution at the 193- and 213-nm laser wavelengths. METHODS: Absorption coefficients were obtained for each of the component species found in balanced salt solution. This was achieved by measuring laser pulse transmission through solutions of varying concentration. The experiments were repeated using the 193-nm excimer and 213-nm solid-state laser wavelengths. Results for each species were then used to obtain an overall absorption coefficient and penetration depth for balanced salt solution and 0.9% sodium chloride solution. RESULTS: Absorption coefficients in balanced salt solution for the 193- and 213-nm wavelengths were found to be 140 and 6.9 cm(-1), respectively. In 0.9% sodium chloride solution, the absorption coefficient was 81 cm(-1) at 193 nm and 0.05 cm(-1) at 213 nm. At 193 nm, absorption in balanced salt solution was dominated by sodium chloride. Sodium citrate emerged as the dominant species of absorption at 213 nm. CONCLUSIONS: For the species investigated, we found reduced absorption for the longer wavelength of 213 nm. While the difference in wavelength between 193 and 213 nm is within about 10%, the respective molar absorption coefficients varied by 1 to 4 orders of magnitude. This indicates that predictions for the wavelength-dependent changes of absorption coefficients of other solutions are unreliable. CLINICAL RELEVANCE: Fluid placed on the surface of the cornea during keratorefractive surgery has proved to be a barrier to ablation for the 193-nm wavelength. The increased penetration depth through sodium chloride solution and balanced salt solution for the longer 213-nm laser wavelength may mean that these solutions cannot be used as a masking agent for keratorefractive procedures performed with this wavelength.

Absorption↗
PubMed1994

Parenteral aluminum loading in critical care medicine. Part I: Aluminum content of infusion solutions and solutions for parenteral nutrition.

BACKGROUND: For patients with disturbed aluminum (Al) excretion, a high Al intake is not without risk. As main aluminum sources infusion solutions and solutions for parenteral nutrition have been identified. This study will give current survey of aluminum loading of the above-mentioned preparations. MATERIAL AND METHODS: The aluminum loading of 139 different infusion solutions and solutions for parenteral nutrition was determined. The solutions were from the clinical pharmacy of the Klinikum Steglitz of the Free University Berlin or were bought in a public pharmacy. The aluminum content was determined by means of two different, independent analytical methods: a) graphite furnace atomic absorption spectroscopy (GFAAS) and b) inductively coupled plasma atomic emission spectroscopy (ICP-AES). The agreement of the measured values was good except for five samples, where different values were found. Mistakes due to contamination were excluded on the basis of the results of measuring standard reference materials. RESULTS: Small-volume additives of TPN (total parenteral nutrition) formulations were highly contaminated with aluminum, e.g. Ca and phosphate solutions (29-12,000 micrograms/l), vitamin C solutions (700-1,200 micrograms/l) and trace element solutions (67-6,200 micrograms/l). Furthermore about 44% of the crystalline amino acid solutions and lipid emulsions had an aluminum content of 25 to 55 micrograms/l. Low aluminum levels were found in carbohydrate solutions, NaCl and KCl solutions and in distilled water (aqua ad injectabilia). CONCLUSIONS: Many of the solutions for parenteral nutritional support have an aluminum content which exceeds, in part considerably, the suggested threshold concentration of 25 micrograms/l (0.93 mumol/l), recommended by the American Society for Clinical Nutrition (ASCN) and the American Society for Parenteral and Enteral Nutrition (ASPEN). The pharmaceutical industry should be required to check the manufacturing process for avoidable sources of contamination, and threshold values for aluminum loading by intravenously applied pharmaceuticals should be laid down in the German and European pharmacopoeia. In cases where contaminations cannot be eliminated during the manufacturing process after careful checking, the aluminum content of the infusion solution should be declared for the user.

Aluminum↗
PubMed1998

A comparison of the University of Wisconsin solution and the modified Kawakami solution for initial flush and coronary perfusion in long-term canine heart preservation.

BACKGROUND: We compared two different solutions, the University of Wisconsin (UW) solution (intracellular-like) and the modified Kawakami (mK) solution (extracellular-like), for initial flush of coronary vascular beds before simple storage and following coronary perfusion. METHODS: After a right thoracotomy in the 4th intercostal space, the donor heart was isolated by ligating the azygos vein and venae cavae, and cross-clamping the aorta. Cardiac arrest was then obtained with a cold GIK solution. Following initial flush of coronary vascular beds, the donor heart was resected, stored utilizing a combination of simple immersion and coronary perfusion, and then transplanted. A total of 48 mongrel dogs was divided into three groups each using different solutions for the initial flush of coronary vascular beds and for coronary perfusion. In group I (n=10) the UW solution was used for both initial flush and coronary perfusion. In group II (n=7) the mK solution was used for both initial flush and coronary perfusion, and in group III (n=7) the UW solution was used for initial flush and the mK solution for coronary perfusion. Intracellular high-energy phosphate was surveyed by 31P-nuclear magnetic resonance spectroscopy. RESULTS: After 12-hour simple immersion and 1-hour coronary perfusion, phosphocreatine and adenosine triphosphate were significantly (p<0.05) higher in group III than in groups I and II. The high-energy phosphate levels of the graft tissue were better in groups I and III than in group II. Orthotopic transplantation was then performed using 10 preserved grafts in group I and seven preserved grafts of group III. After transplantation, left ventricular (LV) pressure of group I animals recovered to 82.3% and group III recovered to 95.8% of the control values. LV dp/dt of group I and III animals recovered to 76.5% and 96.7% of the control values, respectively. CONCLUSIONS: The UW solution, which is acceptable for both initial flush and simple storage, is not suitable for continuous coronary perfusion even for a short period due to its high viscosity. A combination of the UW solution both for initial flush and the following cold simple immersion and the mK solution for continuous coronary perfusion is appropriate for long-term preservation of the canine heart.

Adenosine↗
PubMedDate not supplied

University of Wisconsin solution provides superior myocardial preservation compared with Stanford cardioplegic solution.

The efficacy of the University of Wisconsin solution to safely prolong preservation times for kidney, pancreas, and liver transplantation is established, but its efficacy in enhancing myocardial preservation is not yet clear. We studied the effects of Stanford cardioplegic solution and the University of Wisconsin solution both in preserving the myocardium and in protecting it from the effects of reperfusion injury after 6 hours of preservation. In 28 rat hearts we measured changes in high-energy phosphate content (with magnetic resonance spectroscopy) and histologic changes (edema, endothelial changes, myocyte architecture) during preservation and changes in high-energy phosphate content, histologic status, and performance (aortic systolic and diastolic pressure, heart rate, rhythm) in Langendorff and working hearts during reperfusion. No significant differences in the kinetics of high-energy phosphate changes were noted between the two cardioplegic solutions during preservation. However, at the end of 6 hours of preservation, hearts in the Stanford cardioplegic solution group were more edematous (p < 0.01) than those in the University of Wisconsin group. During reperfusion, no significant differences in the kinetics of high-energy phosphates were noted between the two cardioplegic solutions. None of the hearts in the University of Wisconsin solution group developed ventricular fibrillation at the start of reperfusion, but all hearts in the Stanford group did so. Once sinus rhythm was established no significant differences in developed pressure or heart rate were found between the two solutions. After 2.5 hours of reperfusion, hearts in the Stanford group were more edematous (p < 0.002) and had a greater disruption of myocyte architecture (p < 0.002) and greater arteriolar endothelial injury (p < 0.004). In conclusion, the University of Wisconsin solution better protects the myocardium in this rat model than does Stanford solution. The mechanism for this beneficial effect of the University of Wisconsin solution appears to be due to its better preservation of the microvasculature rather than differences in preservation of high-energy phosphates.

Adenosine↗
PubMed1993

Competitive adsorption of albumin against collagen at solution-air and solution-polyethylene interfaces.

The adsorption of human serum albumin (HSA) from the binary mixtures with collagen was monitored at solution-air and solution-polyethylene interfaces by the in situ measurements. The results clearly demonstrate that on both interfaces albumin is the only adsorbing protein within a large collagen solution concentration range. At the albumin concentration equal to 0.005 mg/mL, the presence of collagen in solution results in the enhancement of albumin adsorption at solution-air interface relative to its adsorption from the single protein system. The same phenomenon is manifested at the solution-polyethylene interface, although the increase in albumin adsorption at this interface occurs at the albumin concentration equal to 0.01 mg/mL. These results are attributed to the lowering in the solution-air and solution-polyethylene interfacial tensions, and thus to the increase in the spreading characteristics of albumin in the presence of collagen molecules. The desorption experiments carried out with a buffer solution on polyethylene surfaces reveal the irreversibility of adsorbed albumin from both the single and the binary mixtures with collagen. When after 20 h of adsorption from the solutions containing albumin only, collagen was added to these solutions or when the samples after that period of time were first rinsed with a buffer and then with a collagen solution, the amounts of albumin remaining at the surfaces were in both cases reduced by one-half.

Adsorption↗
PubMed1988

Reducing cocaine solution use by promoting the use of a lidocaine-phenylephrine solution.

A program to reduce the use of cocaine solution in a university teaching hospital by promoting the use of a lidocaine-phenylephrine solution is described. To reduce the use of cocaine solution, pharmacists promoted the use of a mixture of lidocaine 3% and phenylephrine 0.25% in place of cocaine solution for nasotracheal intubation procedures. Because initial clinical use of the lidocaine-phenylephrine solution by the anesthesia service was successful, the pharmacy department began in December 1986 to actively promote use of the solution to the bronchoscopy service, the emergency service, and select inpatient nursing units. Educational measures included an article in the pharmacy and therapeutics newsletter detailing the safety and efficacy of the solution, pharmacist description of the program to physicians and nurses, and designation of the solution as a free floor stock item on nursing units. By 1988, total cocaine solution use had decreased by 66% from the 1984 average of 145.7 doses per month to an average of 50.0 doses per month; overall use of topical anesthetics remained constant. The nursing staff supported the use of the lidocaine-phenylephrine solution because it eliminated the extensive record keeping necessary for the cocaine solution. The program to decrease the amount of cocaine solution used was successful and will be expanded to other areas of the hospital.

Anesthesia↗
PubMed1998

Hypothermic preservation of isolated rat lungs in modified bicarbonate buffer, EuroCollins solution or St Thomas' Hospital cardioplegic solution.

OBJECTIVES: Inadequate preservation solutions limit lung storage times and, consequently, transplant programs. To address this problem we established an isolated, ventilated and perfused rat lung preparation. Here we report the effects of hypothermic storage in EuroCollins solution, St Thomas' Hospital cardioplegic solution and a modified bicarbonate buffer solution. METHODS: Lungs from male Wistar rats (230-330 g) were perfused via the pulmonary artery with modified bicarbonate buffer (37 degrees C, 15 ml/min, constant flow) and ventilated by positive pressure (tidal volume:1.6-1.8 ml, 80 breaths/min). Vascular resistance (pulmonary artery pressure:perfusate flow ratio) and airways compliance (tidal volume:tracheal pressure ratio) were measured. After a control perfusion period (20 min), lungs were flushed with, then immersed in, bicarbonate buffer (4 degrees C) for varying periods (0-24 h). After storage, lung function was assessed during 20 min reperfusion. Having established a suitable period for study, storage in EuroCollins, St Thomas' Hospital cardioplegic solution or bicarbonate buffer were compared. RESULTS: Pulmonary compliance (ml/cmH2O) was significantly (P < 0.05) reduced in lungs stored for 6 h in modified bicarbonate buffer (0.026 +/- 0.008), EuroCollins solution (0.013 +/- 0.002) or St Thomas' Hospital solution (0.025 +/- 0.005) compared to unstored lungs (0.068 +/- 0.007). Vascular resistance, (1.32 +/- 0.13 cmH2O/ml per min) in unstored lungs, was similar in lungs stored in St Thomas' Hospital solution but increased significantly in lungs stored in modified bicarbonate buffer (3.22 +/- 0.78 cmH2O/ml per min) or EuroCollins solution (4.66 +/- 0.57 cmH2O/ml per min). CONCLUSIONS: Hypothermic storage of rat lungs for 6 h in modified bicarbonate buffer or St Thomas' Hospital solution causes less increase in vascular resistance on reperfusion than EuroCollins solution.

Animals↗
PubMed1997

Efficacy of normal saline solution versus heparin solution for maintaining patency of peripheral intravenous catheters in children.

OBJECTIVES: Literature reports support the use of normal saline solution for maintaining patency of peripheral intermittent intravenous infusion devices (PIID) in the adult population; however, there are limited data regarding this policy in the pediatric population. The purpose of this study was to establish the effects of heparin flush and saline solution flush solutions in maintaining patency of infusion devices in the pediatric population, and to establish cost-saving implications related to both procedures. The specific aims of the study included the following: (1) to determine the efficacy of normal saline solution flush for peripheral i.v. access devices for the pediatric population, and (2) to establish cost-saving implications related to normal saline solution versus heparin flush for PIIDs in terms of pharmacy costs and costs related to nursing time. METHODS: The study was a prospective, randomized, double-blind controlled trial of flushing solutions. The control group (n = 77) received 3 ml of a 10 units heparin/ml normal saline solution i.v. flush. The experimental group (n = 73) received 3 ml of normal saline solution only for the i.v. flush. Routine hospital procedure for flushing was followed during the study period. RESULTS: Descriptive and correlation statistics were used to analyze the data; chi 2, t test, and analysis of variance were calculated. There were no significant differences between the two groups for demographics or complications. Annual cost savings were computed for both procedures with an estimated annual savings of nursing time and unit cost of solutions equaling $27,594. The savings per procedure was estimated at $9.45. DISCUSSION: This study provided support for the efficacy of normal saline solution as an alternative to heparin solutions for the maintenance of peripheral i.v. devices. Implications include elimination of risks associated with heparin (drug incompatibilities, thrombosis syndrome, hypersensitivity reactions, local tissue damage, and iatrogenic hemorrhage); decreased potential for infection associated with breaks in the integrity of the i.v. system; substantial money savings as a result of the change to normal saline solution realized by the patient and the institution; and decreased nursing time. By simplifying the procedure, nurses have more time to provide aspects of nursing care to patients.

Adolescent↗
PubMed1984

Functional and metabolic effects of cardioplegia induced by a young's solution (YNG solution) as assessed in isolated atrial preparations and in isolated perfused heart preparations of the guinea pig.

p6e protective effects of Young's solution (YNG solution), a cardioplegic solution, on the myocardial function and metabolism were assessed in isolated atrial preparations and isolated perfused heart preparations of the guinea pig. In atrial preparations, the time to arrest of the contraction became shorter as the concentrations of the K+, Mg++, and K+-Mg++ solutions increased, while the time to resumption of the contraction was lengthened. There was no difference in the time to arrest between K+ and K+-Mg++ solutions, but the time to resumption was reduced with K+-Mg++ solution to about half the value with K+ solution. YNG solution represented an optimum solution for obtaining a quick cardiac arrest and quick resumption of contraction. In the isolated perfused heart, the time to arrest was similar for all the cardioplegic solutions used and the heart stopped in diastole. However, the time to arrest was longer with cold Krebs-Henseleit's solution (cold cardioplegia). The time to resumption of the contraction was the shortest with YNG solution, which yielded the highest mitochondrial respiratory control ratio (RCR) and ADP/O ratio. There was a negative correlation between the time to resumption of contraction and mitochondrial RCR or ADP/O ratio (r = -0.50 and -0.58, respectively).

Animals↗
PubMed1993

Extended cardiopulmonary preservation: University of Wisconsin solution versus Bretschneider's cardioplegic solution.

Application of the University of Wisconsin cold storage solution has rapidly expanded to include medium-term to long-term preservation of virtually all intraabdominal organs. Its use in intrathoracic organ transplantation has also been suggested. We therefore examined the efficacy of the University of Wisconsin solution in a primate allotransplantation model for preservation of hearts, and as a simple single-solution system for static preservation of heart-lung blocks, for periods of ischemia ranging from 6 to 24 hours. For comparison, we employed the histidine-tryptophane-ketoglutarate cardioplegic solution of Bretschneider. University of Wisconsin solution provided superior results with regard to clinical outcome and hemodynamic recovery of hearts after ischemic periods of up to 16 hours. This was in contrast to Bretschneider's solution, which allowed storage of hearts for periods of only up to 10 hours. Heart-lung blocks were equally well preserved with either University of Wisconsin or Bretschneider's solution after 6 to 12 hours, although the University of Wisconsin solution group exhibited a more notable increase in pulmonary water content. This was in accordance with histological data, which suggested that, although hemodynamic recovery of hearts stored for periods longer than 10 hours was poor, preservation of pulmonary ultrastructure was far superior using Bretschneider's solution as compared with University of Wisconsin solution after an ischemic period of up to 16 hours.

Adenosine↗
PubMed1992

A comparison of histadine lactobionate solution with University of Wisconsin solution for rat liver and heart preservation.

We developed a new solution mainly composed of Na-lactobionate and histidine (HL) and compared the effectiveness of this solution with that of University of Wisconsin (UW) solution using orthotopic liver and heterotopic heart transplantation in rats. The new solution has a higher sodium content and a lower potassium content (Na, 90 mEq/l; K, 45 mEq/l) than UW. Hydroxyethyl starch, adenosine, dexamethasone and insulin are not included. Buffering capacity is increased by adding histidine (90 mM/l) together with KH2PO4 (20 mM/l). Rat liver was perserved in either UW or HL solution hypothermically for 24 h and then transplanted orthotopically into the recipient rat. The heart was preserved in either solution for 18 h and transplanted heterotopically into the recipient rat. The 1-week survival rate for rats receiving livers preserved in UW for 24 h at 4 degrees C was 29% (5/17). In contrast, the new solution (HL) gave a 78% (11/14) survival rate (P < 0.01). The 1-week heart graft survival rate, using UW solution was 50% (3/6), following 18-h cold preservation, whereas all hearts (7/7) continued to beat for over a week using new HL solution (P < 0.05). These results demonstrated that the new HL solution, with a substantial buffering capacity, was superior to UW solution in rat liver and heart preservation.

Adenosine↗
PubMed1991

Effect of solution phase composition on the interaction between aqueous model solutes and polymeric container materials.

The interaction between several marker solutes and a polyolefin laminate polymer was studied in several solutions. Solutions studied included mixtures of sodium chloride and dextrose (at concentrations more less typical of i.v. administration solutions) and several actual i.v. products [lactated Ringer's injection, Dianeal, Travasol (amino acid) injection, and alcohol/dextrose injection]. The interaction properties of the candidate container material correlated well with the solute's octanol-water partition coefficient. For nonionic species, the magnitude of the container/solution interaction was independent of solution phase composition. For the ionic test solute, solution pH, which impacts the speciation of the solute, was the only solution composition variable that significantly influenced the interaction. Thus water (or a weak buffer solution) is suggested as an appropriate model solvent for use in container compatibility evaluations involving i.v.-related products.

Chromatography, High Pressure Liquid↗
PubMed2000

A mathematical model of solute coupled water transport in toad intestine incorporating recirculation of the actively transported solute.

A mathematical model of an absorbing leaky epithelium is developed for analysis of solute coupled water transport. The non-charged driving solute diffuses into cells and is pumped from cells into the lateral intercellular space (lis). All membranes contain water channels with the solute passing those of tight junction and interspace basement membrane by convection-diffusion. With solute permeability of paracellular pathway large relative to paracellular water flow, the paracellular flux ratio of the solute (influx/outflux) is small (2-4) in agreement with experiments. The virtual solute concentration of fluid emerging from lis is then significantly larger than the concentration in lis. Thus, in absence of external driving forces the model generates isotonic transport provided a component of the solute flux emerging downstream lis is taken up by cells through the serosal membrane and pumped back into lis, i.e., the solute would have to be recirculated. With input variables from toad intestine (Nedergaard, S., E.H. Larsen, and H.H. Ussing, J. Membr. Biol. 168:241-251), computations predict that 60-80% of the pumped flux stems from serosal bath in agreement with the experimental estimate of the recirculation flux. Robust solutions are obtained with realistic concentrations and pressures of lis, and with the following features. Rate of fluid absorption is governed by the solute permeability of mucosal membrane. Maximum fluid flow is governed by density of pumps on lis-membranes. Energetic efficiency increases with hydraulic conductance of the pathway carrying water from mucosal solution into lis. Uphill water transport is accomplished, but with high hydraulic conductance of cell membranes strength of transport is obscured by water flow through cells. Anomalous solvent drag occurs when back flux of water through cells exceeds inward water flux between cells. Molecules moving along the paracellular pathway are driven by a translateral flow of water, i.e., the model generates pseudo-solvent drag. The associated flux-ratio equation is derived.

Animals↗