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PubMed2004

[In vitro experimental study of the effects of different introcular irrigating solutions on the viability of rat retinal neuron cells].

OBJECTIVE: To observe the effects of different introcular irrigating solutions on the viability of retinal neuron cells, their antioxidant ability, and to find the ideal introcular irrigating solution. METHODS: Retinal neuron cells from Sprague Dawley rats (postnatal 1 - 3 days) were cultured in the 4 different introcular irrigating solutions which were BSS plus, BSS plus + drugs (tobramycin1.6 ten thousand unit/L, desamethasone 16 mg/L and adnephrin 1 mg/L), new irrigating solution and lactated Ringer's solution + drugs. Cell viability was determinated by MTT [3,(4,5-Dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide] assay, LDH release was tested by LDH assay and apoptotic cell death was evaluated by the TUNEL (TdT-mediated dUTP nick-end labeling) assay after retinal neuron cells were cultured in the different introcular irrigating solutions for 4, 12, 24, 48 hours. MDA (malondialdehyde) production was tested after the cells exposed to 30 micro mol/L H(2)O(2) for 4 hours. All data was analyzed in Dunnett's ANOVA way. RESULTS: The cell viability was decreased and the rate of LDH released and cell apoptosis was increased. These effects were shown to be time-dependent for the same solution. At the same time point, the effects on cellular survive was variable in deferent introcular irrigating solutions, BSS plus is the lowest, BSS plus + drugs and modified irrigating solution are midst, and lactated Ringer's solution + drugs is the highest. The result of MDA assay showed that both BSS plus and modified irrigating solution can inhibit the oxidative damage induced by H(2)O(2). CONCLUSION: Modified introcular irrigating solution may be an better introcular irrigating solution according to its little effect on cell viability, its antioxidant function and lower cost.

Acetates↗
PubMed1994

Effects of cerebroplegic solutions during hypothermic circulatory arrest and short-term recovery.

UNLABELLED: Previous studies have suggested that a simple crystalloid "cerebroplegic" solution may prolong the safe duration of hypothermic circulatory arrest. We tested the hypothesis that pharmacologic modification of the cerebroplegic solution would further enhance cerebral protection. Forty-six 4-week-old miniature piglets underwent core cooling to 15 degrees C nasopharyngeal temperature and 2 hours of hypothermic circulatory arrest. Twelve animals had a 50 ml/kg dose of saline infused into the carotid artery system at the onset of hypothermic circulatory arrest and repeat doses of 10 ml/kg every 30 minutes during arrest. Eleven animals received the same initial and repeat doses of University of Wisconsin organ preservation solution and 10 received University of Wisconsin solution with 7.5 mg/L of MK-801, an excitatory neurotransmitter antagonist. In 13 control animals blood was partially drained from the piglet before 2 hours of circulatory arrest at 15 degrees C and no cerebroplegic solution was infused. All solutions were delivered at 4 degrees C. Brain temperature (n = 24) at the onset of hypothermic circulatory arrest was 15.0 degrees +/- 0.1 degrees C (mean +/- standard error). Brain temperature after cerebroplegic infusion dropped to 13.0 degrees +/- 0.3 degrees C and stayed lower than brain temperature in the control group throughout the hypothermic circulatory arrest period. Recovery of cerebral adenosine triphosphate and intracellular pH determined by phosphorus 31 magnetic resonance spectroscopy (n = 22) was significantly improved by saline infusion and was further improved with University of Wisconsin solution and University of Wisconsin solution plus MK-801 (p < 0.001). Recovery of cerebral blood flow measured by microspheres (n = 24) also was augmented by University of Wisconsin solution (p < 0.001) but not in the presence of MK-801. The vascular resistance response to acetylcholine and nitroglycerin suggested that MK-801 has a direct vasoconstrictive effect. Recovery of cerebral oxygen consumption (n = 24) was increased by University of Wisconsin solution and University of Wisconsin solution with MK-801 (p = 0.002). Brain water content (n = 46) was significantly lower in all cerebroplegia-treated groups than in controls (p < 0.001). CONCLUSION: Cerebroplegia improves short-term recovery after 2 hours of circulatory arrest in hypothermic piglets. Pharmacologic modification with University of Wisconsin solution further improves the recovery of cerebral blood flow and metabolism. MK-801 does not augment the protective effects of University of Wisconsin solution and reduces the recovery of cerebral blood flow by a direct vascular action. Modified cerebroplegia may provide a novel approach to improved cerebral protection when prolonged hypothermic circulatory arrest is necessary.

Adenosine↗
PubMed1990

Endothelial cell toxicity of solid-organ preservation solutions.

Endothelial cell damage caused by myocardial cardioplegic solutions (Bretschneider HTK and St. Thomas' Hospital No. 2) or renal and hepatic cold storage solutions (modified Collins and University of Wisconsin solution) was assessed in monolayer cultures of adult human venous endothelial cells at 4 degrees to 10 degrees C with phase-contrast microscopy. St. Thomas' Hospital solution caused the cells to contract, resulting in disruption of monolayer integrity and opening of intercellular gaps, and resulted in a 24-hour postexposure survival of 51.0% +/- 2.4%. Bretschneider HTK solution altered cellular morphology less and produced the best postexposure survival (80.2% +/- 2.6%; p less than 0.001). Although morphology was altered the least with University of Wisconsin solution, postexposure survival with this solution, which was similar to that with modified Collins solution, was superior to that with St. Thomas' (p less than 0.01) but inferior to that with Bretschneider HTK (p less than 0.05). The superior protection provided by Bretschneider HTK was due to its additives histidine, tryptophan, and KH-2-oxygluterate (p less than 0.005), and to its low chloride content (p less than 0.005). Furthermore, modifying St. Thomas' solution by decreasing its chloride content improved cell survival to 71.2% +/- 2.3% (p less than 0.001). Normothermic (37 degrees C) exposure to Bretschneider HTK, modified Collins, and University of Wisconsin solution was cytotoxic, whereas normothermic exposure to St. Thomas' cardioplegia was not. In conclusion, the preservation solution that is the least harmful to endothelial cells at hypothermia is Bretschneider HTK cardioplegic solution.

Adenosine↗
PubMed1997

Liver transplantation from non-heart beating donors in rats: influence of viscosity and temperature of initial flushing solutions on graft function.

BACKGROUND: We evaluated the effect of warm (37 degrees C) versus cold (4 degrees C) solutions as the initial flush for liver preservation from non-heart beating donors in rats. METHODS: An initial flush was performed just before donor hepatectomy with cold or warm University of Wisconsin solution (UW), UW without hydroxyethyl starch, sodium lactobionate sucrose solution, or lactated Ringer's solution as the control group. A separate group also used as control received no initial flushing. Liver transplantation was performed, and the graft function was determined by survival and assessment of enzyme release. The viscosity of each solution and the vascular resistance of the graft were measured. RESULTS: The 7-day survival rate was 83% and 100% in the warm and cold sodium lactobionate sucrose solution groups and 60% and 50% in the warm and cold lactated Ringer's solution groups, respectively. In the no-initial-flush group, rats did not survive. The 7-day survival rate was 67% and 0% in the warm and cold UW groups, respectively. Eliminating the hydroxyethyl starch from the cold UW improved the survival to 67%. Serum alanine aminotransferase levels 1 day after transplantation in the no-initial-flush and the cold UW groups were significantly higher than those of the remaining groups. At 4 degrees C the viscosity was higher in the UW (86.2 cp) compared to hydroxyethyl starch-free UW solution (30.9 cp), lactated Ringer's solution (24.5 cp), and sodium lactobionate sucrose solution (32.7 cp). The viscosity of UW at 37 degrees C was 34.7 cp. Vascular resistance correlated well with the viscosity. Livers flushed with solutions with a low viscosity showed lower vascular resistance than those flushed with cold UW and led to better survival. CONCLUSIONS: These data suggest that the viscosity of the initial flushing solution may play an important role in determining the outcome of organ procurement from non-heart beating donors.

Adenosine↗
PubMed1992

Warm Carolina rinse solution prevents graft failure from storage injury after orthotopic rat liver transplantation with arterialization.

An injury to nonparenchymal cells, characterized by loss of viability of sinusoidal endothelial cells and activation of Kupffer cells, occurs after reperfusion of livers stored for transplantation. Recently, a new solution, Carolina rinse solution, was shown to prevent reperfusion injury to endothelial cells in vitro almost completely and to improve graft survival after orthotopic rat liver transplantation (ORLT) without arterialization. ORLT with arterialization permits longer cold storage of donor livers and more closely models human surgery. Therefore, we evaluated the effects of Carolina rinse solution on graft survival after ORLT with arterialization in syngeneic Lewis rats. Just prior to implantation, donor livers stored in University of Wisconsin (UW) solution were rinsed with 30 ml of Ringer's solution, saline, or Carolina rinse solution at 1 degree-4 degrees C. In livers stored for 15 h and rinsed with Ringer's or saline solution, long-term graft survival was only 8%. Using Carolina rinse solution containing 1 mmol and 200 mumol adenosine per liter, graft survival improved to 40% and 80%, respectively. Graft survival did not improve when using Carolina rinse solution with adenosine omitted or Ringer's solution containing 200 mumol adenosine per liter. Livers were also rinsed with Carolina rinse solution containing 200 mumol adenosine per liter at 28 degrees-30 degrees C rather than at 1 degree-4 degrees C. With warm Carolina rinse solution, survival improved further to 100%, 80%, and 50% after 15, 18, and 21 h of storage. After 18 h of storage, light and electron microscopy demonstrated marked denudation of the sinusoidal lining and activation of Kupffer cells in grafts rinsed with Ringer's solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed2003

Wettability of polytetrafluoroethylene by aqueous solutions of two anionic surfactant mixtures.

Advancing contact angle (theta) measurements were carried out on mixtures of aqueous solutions of sodium dodecyl sulfate (SDDS) and sodium hexadecyl sulfonate (SHDSs) on polytetrafluoroethylene (PTFE). The obtained results indicate that there were only small contact angle changes over the range of surfactant concentrations in the solution, corresponding to the unsaturated surfactant layer at the aqueous solution-air interface. However, when saturation of the surfactant layer was achieved a considerable decrease in the contact angle (increase in costheta) as a function of concentration was observed. The dependence of costheta on the monomer mole fraction of SHDSs in the mixture of the surfactants (alpha) for aqueous solutions of mixtures at concentrations corresponding to the critical micelle concentration (CMC) had a maximum at alpha=0.2. From the results of these measurements and application of the Gibbs and Young equations the ratio of the excess concentration of surfactants at the solid-aqueous solution interface to the excess of their concentration at the aqueous solution-air interface was calculated. On the basis of the measurements and calculations it was found that there was a straight linear relationship between the adhesion tension and surface tension of aqueous solutions of surfactant mixtures at a given alpha, and that the slope of the obtained straight lines was equal to -1, which suggests that the surface excess of the surfactant concentrations at the PTFE-solution interface is the same as that at the solution-air interface for a given bulk concentration of the surfactant mixtures. The dependence of the surface concentration excess at the PTFE-solution interface on the monomer mole fraction of SHDSs in the mixture of the surfactants for the concentration region of the mixture of aqueous solutions, corresponding to a saturated monolayer, had a maximum at alpha=0.4, probably resulting from increased degree of binding between adsorbed surface-active ions and counterions. It was also found that the critical surface tension of PTFE wetting by aqueous solutions of two anionic surfactant mixtures was equal to 23.35 mN/m, which was higher than the critical surface tension of wetting determined from straight linear dependence between costheta and surface tension of alkanes (19.94 mN/m). This suggests that polar interaction at PTFE-aqueous solutions of surfactant mixtures can probably take place.

Alkanesulfonates↗
PubMed2000

Effects of various arterial infusion solutions on red blood cells in the newborn.

AIM: To examine in vitro the effects of brief contact with various infusion solutions on red blood cells from newborn infants, as occurs in the "waste" syringe during routine blood sampling from umbilical artery catheters. The mixture of blood and solution in the "waste" syringe is usually reinfused into the baby. Reinfused red blood cells may be damaged by the infusion solution. It is hypothesised that an isotonic amino acid solution would cause no red blood cell agglutination and no more haemolysis than many commonly used solutions. METHODS: Blood was obtained from the placentas of 15 normal term babies. Haemolysis was estimated by measuring plasma (free) haemoglobin after mock blood sampling. Agglutination was measured semiquantitatively by direct observation. RESULTS: A 0.25% normal saline solution caused 5.4% haemolysis, significantly more than all the other fluids tested. There was less haemolysis with 0. 25% normal saline when there was complete mixing of blood and solution within the "waste" syringe. Normal saline and isotonic sodium acetate solutions caused < 0.1% haemolysis, significantly less than all the other fluids tested. The isotonic amino acid solution caused 0.8% haemolysis, which is similar to that caused by the remaining solutions tested. Agglutination was seen with isotonic dextrose and with the two isotonic amino acid solutions containing cysteine. CONCLUSIONS: Isotonic amino acid solution (without added cysteine) caused no agglutination and the same or less haemolysis than many commonly used solutions and may offer advantages in nutrition and fluid balance.

Agglutination Tests↗
PubMed2006

Comparison of kinetic characteristics of amino acid-based and dipeptide-based peritoneal dialysis solutions.

UNLABELLED: A mixture of dipeptides (DP) has been proposed as alternatives (to glucose and amino acids, (AA)) osmotic agent in peritoneal dialysis (PD) solutions. DP based solutions may have metabolic and nutritional advantages compared to AA based solutions, as some sources of AA (such as tyrosine) are poorly soluble in water. In a previous study, we compared the kinetic characteristics of DP and AA based solutions; however, the amount of AA differed substantially. The aim of the present study was to compare solutions with almost equal amounts of AA. METHODS: The following solutions were used: (1) amino acid (AA) solution containing leucine, valine, lysine, isoleucine, threonine, phenylalanine and histidine (tyrosine was omitted because of its poor solubility), (2) dipeptide (DP) solution containing leucyl-valine, lysyl-isoleucine, threonyl-phenylalanine and histidyl-tyrosine. Sixteen Sprague-Dawley rats were divided in two groups and were subjected to intraperitoneal injection of either 25 mL of AA (n=8) or DP solution. Dialysate and blood samples were taken frequently postinfusion for measurement of AA and DP concentrations as well as AA from DP. RESULTS: Kinetic models were developed for estimation of diffusive mass transport coefficient between peritoneal cavity and blood (K BD), DP hydrolysis rate coefficient (K H) and AA clearance in the body (K C). Calculations showed that K H is about ten times lower than K BD. Thus, hydrolysis rate in peritoneal cavity is much lower than the diffusive transport rate of DP. K BD for AA appeared to be similar to K BD for dipeptides. K C was much higher than K BD for AA. This finding explains the rapid clearance of amino acids from blood. Nevertheless, the AA-based solution resulted in much higher peak concentrations of AA in blood after 120 min of the dwell than AA concentrations achieved following the use of the DP-based solution. CONCLUSIONS: Peritoneal transport characteristics of AA and DP were similar; however their kinetics in blood differs substantially. The DP solution resulted in a less pronounced increase in AA concentrations in blood, suggesting that DP solution could provide AA in a more physiological way.

Amino Acids↗
PubMed2006

Should adding albumin to parenteral nutrient solutions be considered an unsafe practice?

PURPOSE: The technical issues surrounding the use of albumin in parenteral nutrient (PN) solutions are reviewed. SUMMARY: Five criteria have been suggested to determine which compounds are optimal for addition to PN solutions: (1) stable dosage regimen over 24 hours, (2) pharmacokinetic profile supporting a 24-hour infusion, (3) stable PN solution infusion rate, (4) documented physical stability over at least 24 hours, and (5) documented chemical stability over at least 24 hours. Albumin is stable in solutions containing dextrose and electrolytes, but its stability in solutions containing dextrose and amino acids has not been evaluated. Signs of precipitation and flocculation have been reported when albumin and zinc chloride were added simultaneously to a two-in-one PN solution. Similar to hemoglobin, albumin is nonenzymatically glycosylated in vivo. One of the most common complications associated with the use of PN solutions is catheter-related bloodstream infection. Albumin 25 g/L in two-in-one PN solutions has been shown to clog 0.2-microm filters. Albumin products have historically contained a large amount of aluminum contamination; thus, the addition of albumin to PN solutions would further contribute to accumulated aluminum contaminants in patients receiving PN therapy, particularly neonates. CONCLUSION: Based on the available evidence, the addition of albumin to PN solutions cannot be recommended. The potential for complications due to infection and physical and chemical incompatibility and instability exists. Adding albumin to PN solutions can affect infusion flow rates and pump pressures, thereby compromising the appropriate delivery of PN solutions to patients. The theoretical risk of glycosylation and related complications outweigh potential benefits of albumin administration via PN solution.

Albumins↗
PubMed1995

The buffering ability of commonly employed cardiopulmonary bypass solutions and alkalizing agents.

This experiment evaluated the hydrogen ion (H+) buffering capacity (BC) of solutions and alkalizing agents employed during cardiopulmonary bypass (CPB). A solution's BC can be determined when a known quantity of H+ is titrated into the solution and the change () in pH (-log of the hydrogen ion activity ([H+]a)) is measured ([H+]a/mmole H+). Eleven solutions were studied:Lactated Ringers (LR), 0.9% NaCl (NS), Plasma-Lyte A, Hespan (6% hetastarch), banked donor blood with citrate phosphate dextrose adenine (CPDA-1), fresh donor blood, THAM, sodium bicarbonate (NaHCO3; 1 mEq/ml), high potassium crystalloid cardioplegic solution (HKCCPS), oxygenated crystalloid cardioplegic solution (OCCPS), and adult crystalloid priming solution (AP) per institutional protocol. The solutions were studied at three temperatures: 37 degrees C, 28 degrees C, and 18 degrees C. The null hypothesis stated there was no difference in the BC of the solutions studied. The solutions were first titrated to the same starting pH of 8.0. The solutions were then titrated with a predetermined concentration of hydrochloric acid (HCl) to a pH of 7.0. A higher quantity of H+ added to a solution indicated a greater ability of that solution to buffer H+ within pH limits of 8.0 to 7.0. The data was analyzed with a two way ANOVA and Bonferonni method. A p value < 0.05 was considered to be statistically significant. The significant results of our study indicated that THAM demonstrated the best BC, followed in decreasing order by NaHCO3, banked blood, fresh blood, HKCCPS, AP, OCCPS, Plasmalyte, LR, Hespan, and NS.

Analysis of Variance↗
PubMed2001

Islet cryopreservation using intracellular preservation solutions.

Cryopreservation of islets adds great flexibility to clinical islet transplant programs. Methods of islet cryopreservation have traditionally utilized permeating cryoprotectants contained within isotonic solutions without specifically addressing issues of ionic balances, buffering capacity, or oxygen free radicals that occur during hypothermic stresses. These factors may become significant issues during low-temperature storage and during the freezing and thawing process. Since its development in the early 1980s, the University of Wisconsin (UW) organ preservation solution has become the standard vascular flush and preservation solution. Recently, Hypothermosol preservation solution (HTS) was developed as a hypothermic blood substitute. The unique characteristics and composition of these preservation solutions may be important when developing solutions specific for the cryopreservation of cells and tissues. It was the aim of this study to evaluate these two hypothermic preservation solutions as the media used in cryopreservation of islets. Groups of canine islets [5000 islet equivalents (IE)/group] were cryopreserved using the standard protocol of stepwise addition of dimethyl sulfoxide (DMSO) to 2 M, controlled nucleation, slow cooling (0.25 degrees C/min), and rapid thawing (200 degrees C/min). The cryopreservation solutions were made with 1) UW solution, 2) HTS solution, or 3) Medium 199 solution with 10% fetal calf serum (FCS). Additional control groups included islets cryopreserved using 4) HTS, 5) UW solution, and 6) Medium 199 alone, without DMSO. Recovery of islets immediately following thawing was equivalent between the groups with the exception of the islets cryopreserved without DMSO (groups 4-6, p < 0.05). After 48 h of postcryopreservation tissue culture, islet recovery was highest in the groups frozen with UW and HTS (mean +/- SEM) (79.8 +/- 1.9% and 82.5 +/- 1.5%, p < 0.05 vs. group 3, 69.1 +/- 3.3%, p < 0.05, ANOVA). Less than 15% of the islets were recovered when they were cryopreserved without the cryoprotectant DMSO (groups 4-6). Functional viability was assessed by measuring the glucose-stimulated insulin secretion during static incubation after 48-h culture. The stimulation indexes were 4.6 +/- 1.0, 4.2 +/- 0.8, 3.6 +/- 1.2, 0.6 +/- 0.5, and 0.4 +/- 0.2 for islets in groups 1-5, respectively. This study demonstrates that postcryopreservation survival can be improved using intracellular-based preservation solutions, including UW or HTS, in conjunction with DMSO.

Animals↗
PubMed1987

Endothelium-dependent relaxations in rabbit aorta are depressed in artificial buffered solutions.

Contractile and relaxant responses of rabbit aortae in artificial buffered (Tris and N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) solutions were compared with those in bicarbonate-buffered solution. EC50 values for responses to KCl in aortae equilibrated in Tris and N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid were slightly less than those in bicarbonate; maximum contractions did not differ. There were no significant differences in contractile responses to prostaglandin Fa alpha or histamine in the three buffered solutions. In aortae precontracted with prostaglandin F2 alpha, both acetylcholine and the calcium ionophore, A23187, elicited much less relaxation in artificial buffered solutions than in bicarbonate-buffered solutions. Maximum relaxations to nitroprusside or D600 did not differ among the three solutions. Relaxant responses to isoproterenol were also depressed in artificial buffered solutions. Endothelial damage eliminated relaxant responses to acetylcholine and A23187, as well as the difference in responsiveness to KCl and isoproterenol noted in artificial buffered compared with bicarbonate-buffered solutions. Within the same solution, endothelial damage alone did not alter the responsiveness to KCl or histamine. Total and La -resistant Ca++ binding was similar in all three buffered solutions. Thus, contractile responses are not depressed in Tris- or N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered solutions, whereas endothelium-dependent relaxations are attenuated in similar solutions. Overall, the results imply that, in artificial buffered solutions, the production and/or release of an endothelium derived relaxing factor is attenuated or that its action on aortic smooth muscle is, in some manner, functionally antagonized.

Animals↗
PubMed1983

The physiologic effects of oxygen transport by hemoglobin solutions.

Two chronic animal models and one acute animal model were used to evaluate exchange transfusion with stroma-free hemoglobin solutions. A direct comparison was made between stroma-free hemoglobin solutions having differing oxygen offloading characteristics as well as a colloid solution consisting of 7% bovine albumin. These studies involved a partial exchange involving approximately 50% of the animal's blood volume to simulate a clinically more appropriate partial blood replacement situation. We noted a consistent increase in the arterial oxygen content of animals exchanged with the stroma-free hemoglobin solutions and some modest improvement in oxygen dynamics. Our studies examining myocardial contractility, especially those carried out in the right heart bypass swine preparation failed to substantiate any difference between an exchange with albumin or stroma-free hemoglobin solutions. The conscious animal models examined both at rest and at exercise demonstrated marked differences in exercise response. Animals exchanged transfused with stroma-free hemoglobin solutions often had an almost normal exercise response while those animals exchanged with non-oxygen carrying albumin solution frequently failed to exercise on a treadmill. Blood flow measurements using radiolabeled microspheres were performed in chronically instrumented swine. These animals had a normal variation in organ blood flow during exercise which was noted both during the control period as well as following exchange with stroma-free hemoglobin solutions. Animals exchanged transfused with albumin had a marked derangement in organ blood flow apparently reflecting the decreased oxygen availability. Results from these three studies substantiate a significant benefit to animals undergoing a 50% exchange when that exchange is done with an oxygen carrying solution such as stroma-free hemoglobin solutions as opposed to a non-oxygen carrying but oncotically active solution such as albumin solution. These studies seem to offer encouragement to the continued investigation and ultimate clinical utilization of hemoglobin solutions as an appropriate blood substitute.

Animals↗
PubMed1994

Effects on the peritoneal membrane of rabbits of a single bicarbonate solution containing glycylglycine.

So far, no one has devised ideal, on-line mixed bicarbonate solutions for hemodialysis and continuous ambulatory peritoneal dialysis (CAPD) because current preparations can lead to precipitation of calcium and magnesium carbonate during treatment. The author has prepared a new, single bicarbonate dialysis solution that contains glycylglycine (BiGG). With a bicarbonate/glycylglycine ratio of 30/10 mM/L, this solution has a stable pH of 7.35; sterilized through a 0.22 micron filter, it remains stable for over 15 months when stored at 10 degrees-40 degrees C. When infused (40 mL/kg bw) in rabbits daily for 25 days, the BiGG solution showed excellent peritoneal-membrane tolerance and biocompatibility. Comparative ultrafiltration (UF) studies with BiGG and standard lactate (La) solutions in rabbits showed that net UF with La solution peaked at 2 h and decreased significantly at 4 h and 6 h. Net UF with BiGG solution peaked at 4 h and was sustained at 6 h; in all instance it was greater than that of La solution by approximately 15%, 30%, and 40% at 2, 4, and 6 h, respectively. During the initial 2-h dwell period, the pH of La solution increased from an initial 5.5 to 7.18, whereas that of the BiGG solution remained stable at 7.35. In all rabbits, the peritoneal fluid contained phosphatidylcholine at all times. However, its concentration was significantly higher in animals receiving the BiGG solution than in those receiving the La solution. The author concludes that this new single BiGG PD solution is simple to use, stable, and of a normal pH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1996

[Comparison of the protective prorerties of St. Thomas', Tyers', and Bretschneider's cardioplegic solutions in the neonatal rabbit heart].

Many studies suggest that single-dose and multidose cardioplegia are protective in the ischemic adult heart, but in the neonatal heart single-dose cardioplegia is only protective, whereas multidose cardioplegia is damaging. We examined three clinically used cardioplegic solutions to compare the protective properties of single-dose and multidose cardioplegia in the neonatal rabbit heart (aged 7 to 10 days). The clinical solution studied were St. Thomas', Typers' and Bretschneider's solutions. In isolated working hearts (n = 8/group), cardiac function was assessed prior to 10 hours of ischemia (20 degrees C) and again after 35 min reperfusion (15 min Langendorff, 20 min working). All hearts received a pre-ischemic infusion (10 ml) of cardioplegic solution. The cardioplegic solution was given either as a single infusion (single-dose) or as repeated infusions (multidose) with 5 ml of cardioplegic solution every hour. The changes in coronary vascular resistance (CVR) during repeated cardioplegic infusions were measured in the multidose groups. During 15 min of Langendorff reperfusion, creatine kinase (CK) leakage and CVR were evaluated in all hearts. The results revealed that single-dose cardioplegia provided significantly better functional recovery than multidose cardioplegia in hearts given St. Thomas' or Tyers' solutions, while using Bretschneider solution single-dose cardioplegia Tended to provide better functional recovery. Post-ischemic CK leakages were higher in hearts given Bretschneider's solution in both single-dose and multidose cardioplegia. In hearts given St. Thomas' and Tyers' solutions, post-ischemic CVR in the single-dose group is lower than that in the multidose group, whereas post-ischemic CVR was lowest in the multidose group using Bretschneider's solution. Among multidose groups, CVR prior to reperfusion was lowest in Breschneider's solution as well. In conclusions, these results confirmed that, using the clinical solutions studied, single-dose cardioplegia provided better functional recovery than multidose cardioplegia in the neonatal rabbit heart. However, low CVR in Bretschenider's multidose cardioplegia suggested the better protection in coronary vasculature although functional recovery was poor.

Animals↗
PubMedDate not supplied

Effects of acidity, glucose degradation products, and dialysis fluid buffer choice on peritoneal solute and fluid transport in rats.

OBJECTIVE: To evaluate the effects of acidity, glucose degradation products (GDP), and different solution buffer systems on solute and fluid transport during acute peritoneal dialysis (PD) in rats. DESIGN: Dialysis fluid (16 mL) containing 2.5% glucose as the osmotic agent was instilled intraperitoneally in Wistar rats (280 g) via a thin catheter in dwells lasting 4 hours. Blood and dialysis fluid samples (25 microL) were taken for measurement of glucose, sodium, and radioactive markers. The mass transfer area coefficient (MTAC or PS) for glucose and for 51Cr-EDTA (given as an intravenous infusion) and the peritoneal clearance (Cl) of 125I albumin (RISA), as well as the clearance of RISA to plasma (Cl --> P) were assessed for a commercial, heat-sterilized, acidic PD solution (2.5% glucose, pH 5.5; Gambrosol, Gambro, Lund, Sweden), containing GDP, and for four filter-sterilized solutions containing either lactate (40 mmol/L, pH 5.5 or 7.2), bicarbonate (38 mmol/L, pH 7.2), or pyruvate (40 mmol/L, pH 7.2) as buffers and being devoid of GDP. RESULTS: The initial pH of the acidic solutions increased rapidly, and attained physiological levels within 40 minutes. The initial drop of sodium, which is expected during the first part of the dwell, was significantly more pronounced with neutral than with acidic lactate. The PS for glucose and 51Cr-EDTA were slightly, but significantly, higher with the acidic and heat-sterilized solution (Gambrosol) than with the neutral, sterile-filtered lactate-buffered solution (p < 0.01), especially early during the dwell. Such an increase may be due to initial vasodilatation, and hence, recruitment of capillaries by the combination of acidity and GDP. However, there were no significant differences with respect to small solute PS values among sterile-filtered solutions, regardless of the presence of acidity or of buffer choice. CONCLUSION: There were no major differences in fluid and solute transport among sterile-filtered PD solutions having differing buffer systems and pH. Neither were there any effects of GDP alone. However, the combination of a low pH and the presence of GDP in the PD solutions seemed to cause significant increases in peritoneal small solute transport.

Animals↗
PubMedDate not supplied

Biocompatibility of a peritoneal dialysis solution with amino acids: histological evaluation in the rabbit.

OBJECTIVE: To determine the biocompatibility of a peritoneal dialysis (PD) solution containing amino acids compared to PD solutions containing glucose. DESIGN: The biocompatibility of three dialysis solutions containing 1.1% amino acids, 1.36% glucose, and 3.86% glucose, respectively, was evaluated in vivo in rabbits. METHODS: After 60 days of PD, peritoneal histological changes in rabbits were investigated by light and transmission electron microscopy. The parameters investigated were: (1) mesothelial damage; (2) submesothelial edema; (3) submesothelial cell infiltration; (4) submesothelial fibrosis; and (5) vascular alterations. Semiquantitative evaluations were performed for all the above alterations; quantitative morphometric evaluation was performed for mesothelial damage (cubic transformation of the mesothelium, areas devoid of mesothelium, submesothelial edema) and thickness of peritoneal arteriole walls. RESULTS: (1) Mesothelial damage was practically nonexistent in rabbits dialyzed with the solution containing amino acids, and intermediate and severe with low-glucose and high-glucose solutions, respectively. Both controls and rabbits dialyzed with amino acid solution showed flat continuous mesothelium; rabbits dialyzed with low-glucose solution showed cubic continuous mesothelium; and rabbits dialyzed with high-glucose solution showed cubic discontinuous mesothelium. Cytopathic mesothelial effects were slight with the solution containing amino acids and severe with both the low- and high-glucose solutions. Duplication and thickening of mesothelial basement membrane were never observed. (2) Submesothelial edema showed a worsening trend from controls to rabbits dialyzed with solution containing amino acids, low glucose, and high glucose. (3) No difference in submesothelial infiltration was found between groups. (4) Submesothelial fibrosis was never observed. (5) Vascular alterations were never observed. CONCLUSION: These results are evidence that PD solution with amino acids is more biocompatible than high- and also low-glucose solutions.

Amino Acids↗
PubMed1991

The viability of microorganisms in preservation solutions.

In 1988 the University of Wisconsin solution was introduced into clinical transplantation. This solution is unique in that it contains no glucose but rather raffinose, lactobionate, and hydroxyethyl starch. In addition, it contains two antibiotics, penicillin and bactrim. Prior studies have shown that other preservation solutions allow the transmission of bacterial contamination from organ donor to recipient. However, there are no data on whether UW solution, with its unique composition and extended preservation times, allows bacterial transmission. We undertook the present study to establish if bacteria remain viable in UW solution at extended preservation times. Cultures of both aerobic (Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa) and anaerobic (Bacteroides fragilis) bacteria were suspended at 10(5), 10(4), 10(2), and 10(1) org./ml (calibrated from a .5 Macfarland turbidity standard) in both Eurocollins and UW preservation solutions. Samples were then stored in an ice bath to stimulate organ preservation. The organisms were removed and plated on blood and chocolate agar at 0, 6, 12, 18, 24, and 36 hr postsuspension. The samples were then incubated at 37 degrees C and read for growth at 24-48 hr after plating. Our results showed growth of all organisms except S epi in both preservation solutions, at all dilutions and preservation times. S epi grew in the Eurocollins solution at all dilutions and preservation times but did not grow in the UW solution. When the experiment was repeated omitting penicillin from the UW solution, S epi grew at all dilutions and preservation times. These results demonstrate that in spite of the inclusion of two different antibiotics, the majority of the common bacterial contaminants of the organ donor remain viable in UW solution with extended preservation times. It may be possible therefore to omit these antibiotics from the UW solution and obtain similar results. It is also important to note that routine culturing remains an expensive but necessary part of organ procurement and preservation.

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