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PubMed1992

Evaluation of a pyridoxylated hemoglobin polyoxyethylene conjugate solution as a perfusate for small intestine preservation.

A new type of artificial blood, pyridoxylated hemoglobin-polyoxyethylene conjugate (PHP) solution, (developed by PHP research group of the department of health and welfare of Japan, and produced by Ajinomoto Co., Inc. Tokyo) as an oxygen-carrying component, has been recently devised using hemoglobin obtained from hemolyzed human erythrocytes. Recently, the studies using this solution as a preservation solution were performed in some instances. To examine the mechanism of improved viability using this solution as a preservation solution, we developed a model of orthotopic small intestine transplantation (OIT) in the rat. As a baseline study, we compared parameters of viability of the grafts preserved in Collins and UW solution to those preserved in PHP solution including a survival rate, a serum level total protein and albumin, and a change in body weight after transplantation. In our study, the simple hypothermia storage together with intestinal perfusion preservation with PHP solution was performed. Animals were divided into 6, 12, and 24 hr preservation groups. All of the rats survived after 6 hr preservation following transplantation. However, in 12 hr storage, five of six rats in PHP solution preservation survived and recovery in body weight after grafting was better than those with Collins and UW solution. We conclude that the PHP solution is, therefore, considered to possibly be a more suitable perfusate for small intestine preservation than Collins and UW solution.

Adenosine↗
PubMed1991

Comparative ultrastructural study of rat livers preserved in Euro-Collins or University of Wisconsin solution.

University of Wisconsin solution greatly lengthens the time liver storage is possible compared with all previous solutions used. To test whether this improvement is related to better preservation of the endothelial cell, which is thought to be the most vulnerable cell type in cold storage, we compared time-related ultrastructural changes in rat livers stored in this solution or in Euro-Collins solution. Rat livers were harvested after combined arterial and portal perfusion with the cold-storage solution. They were then preserved for different lengths of time in the same solution at 4 degrees C before being perfusion-fixed and processed for light and electron microscopy. The first preservation damage was noted in endothelial cells; the time course of the lesions was similar in both solutions. After 2 hr of storage, enlarged and ruptured fenestrae with many gaps were observed. Swollen at 4 hr, the endothelial cells became stringlike at 10 hr, leading to stripped sinusoidal walls. Hepatocytes appeared better preserved in University of Wisconsin solution. The amount of glycogen, maintained near the control level at 24 hr in the latter, decreased dramatically between 0 and 4 hr in Euro-Collins solution, as ultrastructurally observed and biochemically confirmed. Furthermore, sinusoidal obstruction by blebs originating from the hepatocytes and quantified by image analysis on electron micrographs was markedly delayed. It was significantly less pronounced in University of Wisconsin solution at 24 hr than in Euro-Collins solution at 2 hr (p less than or equal to 0.05). Our findings confirm that endothelial cells are highly susceptible to preservation damage and show that University of Wisconsin solution does not improve preservation during storage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1993

Cardioplegic effect of University of Wisconsin solution on hypothermic ischemia of rat myocardium assessed by mitochondrial oxidative phosphorylation.

The effectiveness of the University of Wisconsin solution and the Collins' M solution for preservation of rat hearts was compared by examining histologic appearance, tissue water content, and mitochondrial respiratory functions after prolonged hypothermic storage and subsequent heterotopic transplantation. Survival of transplanted hearts after 5 days of reperfusion was markedly lowered by storage in Collins' M solution for 15 hours. Hearts stored in University of Wisconsin solution for 10 hours showed no increase in myocardial necrosis after 5 days of reperfusion, whereas hearts stored in University of Wisconsin solution for 15 hours and Collins' M solution for 10 and 15 hours showed a significant increase in tissue necrosis. University of Wisconsin solution reduced tissue swelling during hypothermic storage, whereas Collins' M solution did not cause such reduction. The yield of mitochondrial protein after reperfusion was significantly decreased by storage in either solution, especially after 15 hours in Collins' M solution. Mitochondrial oxidative phosphorylation was significantly inhibited by storage, especially by storage in Collins' M solution and subsequent reperfusion. These results indicate that myocardial injury, after prolonged ischemia and reperfusion, results in a decrease in functionally and structurally intact mitochondria that is dependent on preservation conditions. University of Wisconsin solution protects isolated hearts against ischemia and reperfusion injury possibly by preventing cellular and mitochondrial deterioration.

Adenosine↗
PubMed1989

Faster gastric emptying for glucose-polymer and fructose solutions than for glucose in humans.

This study examined the rates of gastric emptying for water and 13 different carbohydrate-containing solutions in seven subjects, using conventional gastric intubation techniques. The rates of gastric emptying for water and a 10% glucose-polymer solution were also measured during 90 min of treadmill running at 75% of each subject's maximum oxygen consumption (VO2max). At rest, 15% glucose-polymer (P) and fructose (F) solutions emptied more rapidly from the stomach and provided a faster rate of carbohydrate delivery than did a 15% glucose (G) solution (p less than 0.05). The G solutions showed a constant energy delivery rate of 3.3 kcal.min-1; energy delivery from P and F solutions rose with increasing solution concentrations. The osmolality of the gastric aspirate predicted the rate of gastric emptying for all solutions (p less than 0.05) but overestimated rates of emptying for 10% and 15% P solutions and underestimated emptying rates for 10% and 15% F solutions. Exercise at 75% VO2max decreased the rate of gastric emptying of water but not of 10% P solutions. Thus the different rates of gastric emptying for different carbohydrate-containing solutions were not entirely explained by differences in osmolality. Furthermore, exercise may have different effects on the gastric emptying rates of water and carbohydrate solutions.

Adult↗
PubMed2006

Antibacterial effects of chitosan solution against Legionella pneumophila, Escherichia coli, and Staphylococcus aureus.

Chitosan has been shown to have antibacterial activities on the growth of a wide variety of bacteria. Chitosan solution has been sold commercially for use as an antibacterial agent. Chitosan solution contains not only chitosan but also organic acids as solvents and desalted Japan Sea Proper Water (dJSPW). We aimed to clarify whether chitosan solution has antibacterial activity against bacteria invading bath water, and then to explore the causative factor among these ingredients. The antibacterial activity of full-strength chitosan solution and of 10(2)- and 10(4)-fold chitosan solution diluted with purified water was studied against Legionella pneumophila serogroups 1 (L. pneumophila SG1) and 6 (L. pneumophila SG6), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) for 7 days at 37 degrees C. To clarify the causative factor in the antibacterial activity against E. coli, the antibacterial activities of the full-strength and diluted chitosan solutions for 24 h were examined. L. pneumophila SG1 and SG6, and E. coli could not survive in the chitosan solution or in the 10(2)-fold dilute solution for over a day at 37 degrees C. The cells of S. aureus were found to have decreased more than 2.46 log cfu/ml after 1 day of incubation, not only in the chitosan solutions, but also in phosphate buffer solution as a control. No inhibitory effect of dJSPW on the growth of the bacteria was observed. The antibacterial activity of the chitosan solution was lower compared with those of the organic acids solutions, and it increased with decreasing pH value. We observed the antibacterial activity of chitosan solution against L. pneumophila SG1 and SG6, and E. coli, suggesting it may be due to the decreased pH value derived from organic acids rather than from chitosan itself or dJSPW.

Acids↗
PubMed1999

Stability and compatibility of teicoplanin in parenteral nutrition solutions used in pediatrics.

AIMS: To investigate teicoplanin added to pediatric parenteral nutrition solutions in terms of its stability, its compatibility with parenteral nutrition solution components, and its diffusion through an antibacterial filter material. METHODS: Three binary solutions with and without teicoplanin were studied. Different solution compositions and teicoplanin concentrations were used: A (98.3 +/- 8.2 mg/l), B (116.3 +/- 12.4 mg/l), and C (162.7 +/- 16.2 mg/l). Concentrations of teicoplanin and of solution components, osmolality, and pH of each solution were measured at H0, after 24 h at room temperature, after 24 h at +4 degrees C followed by 24 h at room temperature, and after 144 h at +4 degrees C followed by 24 h at room temperature (H168). Teicoplanin concentrations were also measured before and after passage of each solution through a 0.22 micro filter. RESULTS: Teicoplanin concentrations remained unchanged from H0 to H168 in solutions A (99.6 +/- 8.3 mg/l), B (116.9 +/- 12. 3 mg/l), and C (162.4+12.9 mg/l). During the H0-H168 interval, iron and methionine were the only components that showed significant decreases, which were similar in solutions without teicoplanin [iron, -6.1% (A), -6.8% (B), and -4.5% (C); methionine, -7.3% (A) and -8. 7% (B)] and in those with teicoplanin [iron, -6.2% (A), -7.1% (B), and -4.0% (C, nonsignificant); methionine, -10.5% (A) and -10.7% (B)], indicating that they were not dependent on the presence of teicoplanin. Teicoplanin levels after filtration were identical to prefiltration values in solutions A (86.4 +/- 5.0 vs 89.8 +/- 3.4 mg/l) and B (112.6 +/- 4.3 vs 115.3 +/- 9.0 mg/l) but were 10.0% lower in solution C (161.6 +/- 3.9 vs 145.4 +/- 4.0; P << 0.001). CONCLUSIONS: Teicoplanin can be added to pediatric parenteral nutrition solutions to treat central venous catheter-related infections due to teicoplanin-susceptible organisms since its concentrations and those of solution components remain stable over time.

Anti-Bacterial Agents↗
PubMed2006

Testing assumptions about solute concentration dependence in liquid crystal NMR.

The NMR spectra of four solutes, used as probes of liquid crystal orientational order, were analyzed. For each solute, samples were prepared at different solute concentrations, and the concentration dependence was used to extrapolate zero-concentration properties. The mean-field (Maier-Saupe) model when applied to solutes neglects solute-solute interactions and assumes all solutes in a mixed-solute sample see the same average environment. The first assumption is only valid as one approaches zero concentration, while experiments are typically carried out at concentrations between 0 and 10 mol %. The solute concentration dependence has in the past been "scaled out" using an internal solute reference as an orientational standard. We measured the concentration dependence of the orientational order parameter and calculate the corresponding interaction energies based on a mean-field interaction potential for a solute. We find agreement at the 3% level between experiments for different solutes while using (i) the zero-concentration values as solute-dependent orientational references and (ii) scaling to either order parameters or interaction energies; these two scalings gave equivalent but not identical results. We find, too, that errors inherent in the experiment and the calculations will limit attempts to refine the theory to push the comparisons beyond the 2% level.

Journal Article↗
PubMed2004

Stabilization of model membranes during drying by compatible solutes involved in the stress tolerance of plants and microorganisms.

Many organisms accumulate compatible solutes under environmental stress conditions. Cyanobacteria accumulate compatible solutes in response to increased external salinity, with tolerance increasing from Suc (sucrose) or trehalose to 2-O-(alpha-D-glucopyranosyl)-glycerol and glycinebetaine accumulating species. It is not clear how these different solutes influence salt tolerance. One possible explanation may be a differential ability of these solutes to stabilize membranes under stress conditions. We therefore performed drying experiments with liposomes in the presence of compatible solutes. Suc, trehalose and sorbitol protected liposomes from leakage of a soluble marker and from membrane fusion during drying and rehydration. 2-O-(alpha-D-glucopyranosyl)-glycerol was less effective and glycinebetaine showed hardly any effect. In combination with Suc, the latter two solutes showed improved protection. Lipid-phase transitions are known to contribute to solute leakage from liposomes. We determined phase transitions in dry membranes in the absence or presence of the solutes, using Fourier-transform infrared spectroscopy. The ability of the solutes to decrease the phase transition temperature corresponded closely to their ability to protect the liposomes against solute leakage. All solutes interacted with the phosphate in the lipid headgroups. The magnitude of the shift in the asymmetric P=O stretching vibration correlated closely with the lipid-phase transition temperature. This indicates that the degree of membrane protection afforded by the solutes is mainly determined by their ability to interact with the membrane lipids. However, this is not a determinant of cellular protection against salt stress, as the solutes show a reverse order when ranked with regard to protection against these stresses.

Betaine↗
PubMed2003

Stability and microbiology of inhalant N-acetylcysteine used as an intravenous solution for the treatment of acetaminophen poisoning.

STUDY OBJECTIVE: Intravenous N-acetylcysteine has been used as an antidote for acetaminophen poisoning for more than 25 years in Europe and Canada. In the United States, only the oral administration of N-acetylcysteine is approved by the US Food and Drug Administration. Many physicians routinely use the inhalant preparation as an intravenous formulation; however, no stability, microbiology, or pyrogen studies have been performed. In this study, we evaluate the stability and microbiology of inhalational N-acetylcysteine compounded as an intravenous formulation. METHODS: A total of 8 N-acetylcysteine solutions (solution A through H) were prepared by injecting 150 mL of 20% solution through a 22-microm filter to 1 L of 5% dextrose (D(5)W; 2.6% solution). Solutions A through C were prepared at ambient conditions (25 degrees C [77 degrees F], 65% relative humidity), and solution D was prepared at accelerated conditions (40 degrees C [104 degrees F], 75% relative humidity) for stability testing. The assays were performed by means of high-performance liquid chromatography at 0, 4, 8, 12, 24, 36, 48, 60, and 72 hours according to US Pharmacopeia XXIV methodology. Solutions E through G were assessed for bacterial growth, and solution H underwent pyrogen testing by using a Limulus amebocyte lysate method. RESULTS: Solutions A through C remained stable for at least 60 hours (<10% decomposition), but at 72 hours, there was a 10.3%, 14.9%, and 13.4% degradation, respectively. Under accelerated conditions (solution D), stability lasted for more than 72 hours. Solutions E through G remained free from bacterial growth at 72 hours, and solution H tested negative for endotoxins-pyrogens. CONCLUSION: Inhalational N-acetylcysteine prepared as an intravenous solution meets US Pharmacopeia standards for stability up to 60 hours and is free from bacteria and their byproducts, offering a viable alternative to the traditional use of oral N-acetylcysteine.

Acetaminophen↗
PubMed2002

Tissue-dissolving capacity and antibacterial effect of buffered and unbuffered hypochlorite solutions.

OBJECTIVE: The goal of this study was to compare the dissolving potential of Dakin's solution with that of equivalent buffered and unbuffered sodium hypochlorite solutions on fresh and decayed tissues. In addition, the antimicrobial effect of Dakin's solution and equivalent unbuffered hypochlorite was tested. STUDY DESIGN: Tissue specimens were obtained from freshly dissected pig palates. Unbuffered 2.5% and 0.5% sodium hypochlorite solutions and 0.5% solutions buffered at a pH of 12 and a pH of 9 (Dakin's solution) were tested on fresh and decayed tissue. Tissue decay was assessed histologically. Antimicrobial testing was performed with Enterococcus faecalis in dentin blocks and on filter papers. RESULTS: The 2.5% NaOCl solution was substantially more effective than the three 0.5% solutions in dissolving the test tissues. Buffering had little effect on tissue dissolution, and Dakin's solution was equally effective on decayed and fresh tissues. No differences were recorded for the antibacterial properties of Dakin's solution and an equivalent unbuffered hypochlorite solution. CONCLUSIONS: In contrast to earlier statements, the results of this study do not demonstrate any benefit from buffering sodium hypochlorite with sodium bicarbonate according to Dakin's method. An irrigation solution with less dissolving potential may be obtained by simply diluting stock solutions of NaOCl with water.

Analysis of Variance↗
PubMed1996

Phase I study of the safety and pharmacologic effects of diaspirin cross-linked hemoglobin solution.

OBJECTIVE: To evaluate the safety, pharmacokinetics, and pharmacodynamics of diaspirin cross-linked hemoglobin solution (DCLHb) in normal, healthy volunteers. DESIGN: Randomized, double-blind, controlled, crossover study. SETTING: Phase I research facility of a contract research organization. PATIENTS: Twenty-four healthy adult volunteers. INTERVENTIONS: Diaspirin cross-linked hemoglobin solution (25, 50, or 100 mg/kg) or equal volume of lactated Ringer's solution was infused on day 1; the alternate solution was infused 6 days later. Laboratory analyses, electrocardiograms, and Holter and telemetry monitoring were performed to assess organ function, pharmacokinetics, and potential toxicity. Vital signs, pulse oximetry, laser Doppler flowmetry, and toe temperature were measured to evaluate diaspirin cross-linked hemoglobin solution's pharmacodynamic effects. MEASUREMENTS AND MAIN RESULTS: There were no serious adverse events associated with diaspirin cross-linked hemoglobin solution infusion. Abdominal pain occurred in three subjects after control infusion and in six subjects after diaspirin cross-linked hemoglobin solution infusion; no treatment was required. A dose-related increase in lactic dehydrogenase (LDH)-5 isoenzyme concentrations was observed in 12 subjects after diaspirin cross-linked hemoglobin solution infusion. There were no associated increases in the circulating concentrations of total LDH, aspartate aminotransferase, alanine aminotransferase, or alkaline phosphatase. Total serum creatine kinase concentrations increased significantly after infusion of 100 mg/kg of diaspirin cross-linked hemoglobin solution; the isoenzyme creatine kinase-myocardial band (CK-MB) was not increased, nor were there any abnormal electrocardiogram findings. There were no differences in laser Doppler, pulse oximetry, or toe temperature measurements during or after either infusion. The half-life of diaspirin cross-linked hemoglobin solution was 2.5 hrs for the 25- and 50-mg/kg doses and 3.3 hrs for the 100-mg/kg dose. A dose-related increase in blood pressure occurred with diaspirin cross-linked hemoglobin solution. CONCLUSIONS: Diaspirin cross-linked hemoglobin solution doses of 25, 50, and 100 mg/kg are well tolerated, without evidence of organ dysfunction or toxicity. Diaspirin cross-linked hemoglobin solution's pressor effect is without evidence of decreased peripheral perfusion. Further investigations of its use in certain patient populations are warranted.

Adult↗
PubMed2005

Phenol-containing saline solution as a diluent for adenosine 5'-monophosphate in bronchial challenge testing.

OBJECTIVES: To investigate the effect of dissolving adenosine 5'-monophosphate (AMP) with phenol-containing saline solution on the stability and the bronchoconstrictive properties of this indirect agonist. METHODS: Eleven subjects with asthma well controlled with short-acting inhaled beta2-agonists as required or with inhaled corticosteroids were studied. Bronchial challenge tests with AMP dissolved with either normal saline solution or saline solution containing 0.4% phenol were performed on separate days. Furthermore, to assess the potential influence of the phenol-containing saline solution on the stability of the bronchoconstrictor agent, AMP solutions in concentrations of 40 microg/mL and 400 microg/mL were prepared in saline solution and phenol-containing saline solution and, after 30 min, the AMP levels were determined by high-performance liquid chromatography (HPLC) assay. RESULTS: The geometric mean AMP provocative concentration causing a 20% fall in FEV1 (PC20) was 13.49 mg/mL (95% confidence interval [CI], 6.76 to 26.91) for the saline solution method, and AMP PC20 for the saline solution with phenol method was 8.91 mg/mL (95% CI, 3.39 to 23.44) [p = 0.18]. No significant differences were found between the concentrations of AMP made in saline solution compared to those made in phenol-containing saline solution measured by HPLC. CONCLUSION: These observations indicate that normal saline solution with or without phenol can be used as the diluent for AMP. However, since a potential risk with AMP of industrial sources is the bacterial contamination, adding a preservative such as phenol to a saline solution diluent might be recommended.

Adenosine Monophosphate↗
PubMed1995

Evaluation of the effects of saline versus bicarbonate-containing mixed salts solutions on rabbit corneal epithelium in vitro.

Rabbit corneas were incubated, over 4 h in vitro, with the corneal epithelial surface exposed to various solutions to assess their utility as incubation solutions for physiological, pharmaceutical or toxicological studies. The corneal endothelium was perfused with a 35 mM bicarbonate-mixed salts solution equilibrated at 36 degrees C. Corneal thickness, corneal hydration or epithelial cell appearance (as assessed by scanning electron microscopy) were found to be similar to in vivo if a 35 mM bicarbonate, mixed salts solution (equilibrated with 5% CO2-air) was used for the epithelium. Some swelling (14 microns h-1), increased hydration and minor cell exfoliation were seen if this 35 mM bicarbonate solution was equilibrated with 5% CO2-95% O2 (hyperoxia). Solutions with only 5 mM bicarbonate (0.5% CO2-air) produced rapid swelling, large increases in hydration and marked cellular damage. Slightly hypertonic (310 mOsm kg-1) solutions containing 5 mM bicarbonate caused some swelling at 15 microns h-1, small increases in hydration and some cell damage but the swelling and cellular damage were further reduced by making the solution slightly more hypertonic (325 mOsm kg-1) by addition of NaCl and KCl. Saline (NaCl 0.9% or 0.97%) or phosphate-buffered saline (PBS) (300 mOsm kg-1) produced swelling at 21-28 microns h-1, 30% increases in hydration and almost total destruction of the superficial cell layers. These studies confirm in vivo experiments that saline (and also buffered saline solutions) are rather toxic to the corneal epithelium and thus should not be used as epithelial incubation solutions. Even when using mixed salts solutions and even with bicarbonate present, small differences in composition can have marked effects on corneal thickness, hydration or cell appearance. Hyperoxic solutions appear to be mildly cytotoxic compared with normoxic solutions.

Animals↗
PubMed2003

Repeated constriction to respiration-induced hypocapnia is not mimicked by isocapnic alkaline solution in rabbit basilar artery in situ.

The purpose of this study was to test whether constriction of the cerebral vasculature in response to respiration-induced hypocapnia was mimicked by isocapnic alkaline solution. Since the regulation of the cerebral vasculature by hypocapnia necessitates vessels to constrict repeatedly in response to hypocapnic challenge, we tested whether repeated challenge with isocapnic alkaline solution was also associated with constriction. In contrast to our previous demonstration that repeated hypocapnic challenge elicited constrictions of similar magnitudes in rabbit basilar artery in situ, repeated challenge with isocapnic alkaline solution resulted in reduced constriction. Constriction to hypocapnia was also reduced following isocapnic alkaline solution. Since we previously demonstrated that constrictions to hypocapnia and isocapnic alkaline solution were endothelin-1 dependent, we tested whether the inhibition of hypocapnia- and isocapnic alkaline solution-induced constrictions following isocapnic alkaline solution was due to reduced endothelin-1 constriction. Endothelin-1 constriction was not reduced following isocapnic alkaline solution. Thus, constriction to isocapnic alkaline solution does not mimic constriction to hypocapnia. The results further suggest that the decreased constriction to isocapnic alkaline solution is due to blockade of endothelin-1 release, and that both hypocapnia and isocapnic alkaline solution share a common step in their endothelin-1 release pathways that can be inhibited by isocapnic alkaline solution.

Animals↗
PubMed1997

Effects of an isotonic oral rehydration solution, enriched with glutamine, on fluid and sodium absorption in patients with a short-bowel.

AIM: To compare the effects of a standard oral rehydration solution with a polymeric glucose isotonic solution enriched with glutamine on water and sodium absorption in the short bowel. METHODS: Six patients with high jejunostomy were tested in a random order on 2 consecutive days with the standard solution (20 g/L glucose, 94 mmol/L sodium, 292 mOsm/kg osmolality) and a solution containing maltodextrins (18 g/L Glucidex 12; hydrolysis of 18 g of Glucidex 12 yields 20 g glucose) enriched with 14.6 g/L of glutamine (94 mmol/L sodium, 282 mOsm/kg osmolality). Solutions were administered via a naso-gastric tube at a rate of 2 mL/min. Jejunal effluent for each solution was collected during an 8-h period, after a 14-h equilibrium period. RESULTS: The net 8-h fluid absorption was not significantly different between the standard solution and the solution with glutamine (333 +/- 195 and 213 +/- 251 mL, respectively (mean +/- S.E.M.)). Net sodium absorption was higher for the standard solution than for the solution with glutamine (15 +/- 15 vs. 2 +/- 20 mmol, P < 0.05). The rate of glucose absorption was not different between the solutions. CONCLUSION: The replacement of glucose by maltodextrins and the addition of glutamine to the standard oral rehydration solution, without changing its sodium content or osmolality, results in a reduction of sodium absorption in the short-bowel syndrome.

Adult↗
PubMed1995

University of Wisconsin solution preserves myocardial calcium current response to isoproterenol in isolated canine ventricular myocytes.

BACKGROUND: University of Wisconsin (UW) solution has been shown to be an effective solution for cold storage of various organs. This study was designed to evaluate the subcellular protective mechanism of UW solution during cardiac myocyte storage using patch-clamp techniques for the first time as a tool for the detection of myocyte viability. METHODS AND RESULTS: The protective effects of UW solution on the preservation of dihydropyridine-sensitive Ca2+ channel current response to catecholamine were evaluated in canine cardiac ventricular cells by measurement of single channel open probability. Single ventricular myocytes were isolated and stored in UW solution, in Stanford (SF) solution, or in St Thomas' (ST) solution at 4 degrees C for 2, 6, 12, and 24 hours, and after each storage period, recordings were made of cell-attached single Ca2+ channel currents. When 0.1 mumol/L isoproterenol was applied, percent mean open probability of the Ca2+ channel tested in freshly isolated cells was 167 +/- 4% (n = 24) of controls (100%). The response was decrescent with increased duration of the hypothermic storage and was only 130 +/- 12% (n = 4) after 24 hours of storage in SF solution and 135 +/- 9% (n = 7) in ST solution. However, it was significantly highly preserved as much as 165 +/- 9% (n = 6) in UW solution. Ca2+ channel kinetics and channel conductance were not changed after up to 24 hours of hypothermic storage. CONCLUSIONS: Hypothermic storage of canine cardiac myocytes in UW solution preserved beta-adrenergic response, which suggests that UW solution during cold storage preserved high-energy phosphates in myocytes that are responsible for Ca2+ channel phosphorylations.

Adenosine↗
PubMed2006

Effect of suckling isotonic or hypertonic solutions of sodium bicarbonate or glucose on abomasal emptying rate in calves.

OBJECTIVE: To determine and compare the abomasal emptying rates in calves suckling milk replacer or an isotonic or hypertonic solution of NaHCO(3) or glucose. ANIMALS: 5 male Holstein-Friesian calves that were < 30 days of age. PROCEDURES: Calves were fed 2 L of milk replacer or isotonic (300 mOsm/L) or hypertonic (600 mOsm/L) solutions of NaHCO(3) or glucose containing acetaminophen (50 mg/kg). Venous blood samples and transabdominal ultrasonographic abomasal dimensions were obtained periodically after feeding, and abomasal luminal pH was continuously monitored by placement of a luminal pH electrode through an abomasal cannula. Abomasal emptying rate was assessed by the time to maximal plasma acetaminophen concentration, ultrasonographic determination of the half-time of abomasal emptying, and the time for luminal pH to return to within 1 pH unit of the preprandial value. RESULTS: Hypertonic NaHCO(3) solution was emptied slower than an isotonic NaHCO(3) solution, isotonic glucose solution was emptied slower than an isotonic NaHCO(3) solution, and hypertonic glucose solution emptied slower than an isotonic glucose solution. CONCLUSIONS AND CLINICAL RELEVANCE: An electrolyte solution for oral administration with a high osmolarity and glucose concentration may lead to a slower resuscitation of dehydrated diarrheic calves because such solutions decrease the abomasal emptying rate and therefore the rate of solution delivery to the small intestine. Whether slowing of the abomasal emptying rate in dehydrated diarrheic calves suckling an oral electrolyte solution is clinically important remains to be determined.

Abomasum↗
PubMedDate not supplied

Improved heart preservation with UW preservation solution.

Despite the good clinical results obtained with the current heart preservation techniques, these methods need to be improved. The UW solution has provided excellent preservation for the pancreas, kidney, and liver after extended cold ischemic storage times. We have tested the ability of the UW solution to store hearts for 5 and 12 hours and compared the results with those obtained from hearts preserved by either Stanford or modified Collins' solutions. Three groups of five canine hearts each underwent 5 hours, and three groups of five canine hearts underwent 12 hours of ischemia at 4 degrees C. Then the hearts were reperfused in an isolated working canine heart preparation. Those hearts preserved for 5 hours had nearly normal ventricular function and adenosine triphosphate contents and were able to maintain normal tissue electrolyte concentration and water contents. After 12 hours of storage time only adenosine triphosphate contents were similar among the groups. Hearts preserved with the UW solution rapidly recovered, reaching nearly normal left ventricular function by 60 minutes of reperfusion; hearts preserved by the modified Collins' solution recovered more slowly, but function was good after 120 minutes of reperfusion. Hearts preserved by the Stanford solution never attained adequate function. The three groups of hearts preserved for 12 hours did not differ in their ability to utilize lactate or in their rates of oxygen utilization. Tissue water and sodium contents were considerably lower in the hearts preserved with the UW solution after 150 minutes of reperfusion compared with hearts stored in the modified Collins' or Stanford solutions. Hearts stored 12 hours in the UW solution under cold ischemic conditions recovered left ventricular function rapidly after reperfusion with normal blood, utilized lactate and oxygen at normal rates, and were able to regulate tissue water and sodium contents to nearly normal levels. Because of the superior preservation obtained by the UW solution, the solution deserves further evaluation for possible future use in clinical heart transplant programs.

Adenine Nucleotides↗