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1
Nakata, T., W. Berard, E. Kogosov, and N. Alexander. "Hypothalamic NE release and cardiovascular response to NaCl in sinoaortic-denervated rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 260, no. 4 (April 1, 1991): R733—R738. http://dx.doi.org/10.1152/ajpregu.1991.260.4.r733.
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We determined the activity of noradrenergic neurons in the nucleus of the posterior hypothalamus (PH) of sinoaortic-denervated (SAD) and sham-operated (SO) rats during cardiovascular responses to intravenous (iv) or local brain dialysis of NaCl. PH extracellular norepinephrine (NE) was collected by microdialysis from freely moving rats, and dialysate NE was measured by radioenzymatic assay. Three days after SAD or SO, mean arterial pressure (MAP) and heart rate (HR) were significantly higher in SAD rats than SO rats. Basal levels of PH dialysate were also significantly elevated in SAD rats. Local dialysis of PH with hypertonic NaCl produced pressor and tachycardiac responses coupled with increased NE release in PH in both groups, but the increases in MAP and dialysate NE were larger in SAD than SO rats. Ganglionic blockade with iv hexamethonium elicited significantly larger depressor and bradycardiac responses in SAD rats, whereas the percent increase of dialysate NE was smaller than that of SO rats. The iv infusion of hypertonic NaCl produced larger pressor responses in SAD than SO rats and a significant increase in dialysate NE from PH of SAD but not SO rats. These findings indicate that 1) PH is an important site of NaCl action and 2) noradrenergic input in PH receives tonic inhibitory input from baroreflex pathways and contributes to cardiovascular hyperactivity and hypertension in SAD rats.
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Oettinger, C. W., and J. C. Oliver. "Normalization of uremic acidosis in hemodialysis patients with a high bicarbonate dialysate." Journal of the American Society of Nephrology 3, no. 11 (May 1993): 1804–7. http://dx.doi.org/10.1681/asn.v3111804.
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Uremic acidosis accompanies chronic renal failure in hemodialysis patients because of a retention of nonvolatile acids. Standard bicarbonate (39 mEq/L) and acetate (38 mEq/L) dialysates do not completely correct the acidosis. The acid-base and biochemical effect of a high-bicarbonate (42 mEq/L) dialysate was evaluated in 38 patients during high-efficiency and high-flux dialysis over 12 wk. All patients were dialyzed on standard bicarbonate dialysate before the study and for 8 wk after the study. In order to monitor potential excessive alkalosis, predialysis and postdialysis arterial blood gases were measured in seven patients who initially had a normal predialysis pH. Serum chemistries revealed no significant changes in predialysis BUN, calcium, ionized calcium, or phosphorus during the 12-wk study. There was no change in postdialysis ionized calcium or phosphorus. Predialysis and postdialysis serum total CO2 (STCO2) increased over the 12-wk study (P < 0.0001). By week 12, 75% of the hemodialysis patients had an STCO2 > 23 mEq/L and no patient had an STCO2 > 30 mEq/L predialysis. After the 8-wk washout, all chemistries were no different from prestudy concentrations. Predialysis blood gases in seven patients with normal predialysis HCO3 revealed a significant increase (P < 0.009) in PCO2 and HCO3 over the 12-wk study; predialysis pH and PO2 did not change. There was no significant change in postdialysis blood gases. It was concluded that: (1) a high-bicarbonate dialysate corrects predialysis acidosis in 75% of hemodialysis patients without causing progressive alkalemia, hypoxia, or hypercarbia; and (2) predialysis BUN, calcium, ionized calcium, and phosphorus are unaffected by high-bicarbonate dialysate.
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Cave, Grant, Rachel Kee, Martyn Harvey, and Zimei Wu. "pH Gradient Liposomes Extract Protein Bound Amitriptyline in Peritoneal Dialysis—Exploratory Work." International Journal of Molecular Sciences 23, no. 19 (September 30, 2022): 11577. http://dx.doi.org/10.3390/ijms231911577.
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Poisoning is a significant cause of injury-related death worldwide. Dialysis is usually ineffective in removing the toxin once it has been absorbed because of drug protein binding and high volumes of distribution. In this work, we explore whether the addition of liposomes to peritoneal dialysate could extract protein bound amitriptyline. Liposomes were prepared using the thin film hydration method. In the in vitro experiment, 3 mL of 20% albumin with a concentration of 6000 nmol/L amitriptyline in a proprietary dialysis cartridge was dialysed against 125 mL of phosphate-buffered saline with and without 80 mg 1,2-dioleoyl-sn-glycero-3-phosphoglycerol (DOPG) liposomes. In the in vivo arm, peritoneal dialysis was undertaken in 6 rats with pH gradient liposome augmented dialysate after intravenous amitriptyline injection. Peritoneal blood flow was estimated by CO2 extraction. Total amitriptyline extracted was compared to freely dissolved (non-protein bound) and total amitriptyline perfusing the membrane during the peritoneal dwell. Mean liposome size for DOPG and acidic centre pH gradient liposomes was 119 nm and 430 nm, respectively. In the in vitro experiment, more amitriptyline was extracted into the liposome containing dialysate than the control dialysate (40 +/− 2 nmol/L vs. 27 +/− 1 nmol/L). In the in vivo experiment, the total amitriptyline in dialysate was 5240 +/− 2750 nmol. Mean total free amitriptyline perfusing the peritoneal membrane was 93 +/− 46 nmol. Mean total blood amitriptyline perfusing the peritoneal membrane was 23,920 +/− 6920 nmol. Two of the six animals were excluded due to overestimation of peritoneal blood flow. This exploratory work suggests the addition of liposome nanoparticles to peritoneal dialysate extracted protein bound amitriptyline from blood.
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Pawlaczyk, Krzysztof, Malgorzata Kuzlan-Pawlaczyk, Katarzyna Wieczorowska Tobis, Alicja Polubinska, Justyna Wisniewska, Dirk Faict, Cliff J. Holmes, and Andrzej Breborowicz. "Bicarbonate/Lactate Dialysis Solution Improves In Vivo Function of Peritoneal Host Defense in Rats." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 19, no. 2_suppl (February 1999): 370–77. http://dx.doi.org/10.1177/089686089901902s60.
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Objective To assess the in vivo peritoneal inflammatory reaction in rats dialyzed with neutral, bicarbonatelactate-buffered dialysis fluid. Methods Chronic peritoneal dialysis was performed for 4 weeks in Wistar rats with two solutions: (1) 40 mmol/l lactate-buffered fluid, pH 5.2, with a glucose concentration of 2.27 gldl (lac); and, (2) 15 mmolll lactate and 25 mmolll bicarbonate-buffered fluid, pH 7.0 -7.5, with a glucose concentration of 2.27gldl (Bic-lac). After 4 weeks, two peritoneal equilibration tests (PET 1 and PET 2) were performed in all animals with each respective solution. PET 1 was done with test solutions alone, whereas, on a subsequent day, PET 2 was performed with test solutions supplemented with endotoxin [lipopolysaccharide (IPS)] to induce peritonitis. Results During PET 1 no consistent differences were detected in peritoneal permeability between the lac and Bic-lac groups. Total dialysate cell count in the Bic-lac animals was lower than in rats treated with lac fluid: that is, at 8 hours, the respective counts were 1858 ± 524 cellslμl versus 2785 ± 1162 cellslμl (p < 0.01). Dialysate from animals dialyzed with Bic-lac contained more macrophages (at 4 hours: 53.6% ± 35.8% versus 35.8% ± 8.8%, p < 0.001) and fewer neutrophils (at 4 hours: 3.6% ± 1.8% versus 15.4%± 6.1%, p < 0.001) as compared to those dialyzed with the lac solution. Concentration of nitrites in 8-hour dwell dialysate samples from Bic-lac rats was lower than that in the lac group (0.98 ± 0.28 μmollml versus 2.32 ± 0.87 μmollml, p < 0.002), but cytokine levels in the dialysates were comparable. During PET 2, the in -crease in peritoneal permeability resulting from the lPS induced inflammatory response was similar for both test solutions. Dialysate cell count was higher in the lac group versus the Bic-lac group (at 8 hours: 8789 ± 4862 cellslμl versus 3961 ± 581 cellslμl, p < 0.001), contained more neutrophils (at 8 hours: 80.0% ± 11.3% versus 54.8% ± 4.4%, p < 0.001) and fewer macrophages (at 8 hours: 6.8% ± 5.6% versus 21.2% ± 3.3%, p < 0.05). During peritonitis, we found a higher overall dialysate concentration of both tumor necrosis factor (TNFα: +53%, p < 0.05) and of interferon gamma (lFN-y: +303%, p < 0.02), in the Bic-lac group than in the lac group. Conclusions A lower dialysate cell count, higher percentage of macrophages, and lower percentage of neutrophils in dialysate suggest that Bic-lac fluid induces a diminished nonspecific inflammatory response of the peritoneal cavity during dialysis. However, after in vivo stimulation, peritoneal cells from animals dialyzed with Bic-lac solution possess an augmented ability to produce inflammatory cytokines.
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Nakata, T., W. Berard, E. Kogosov, and N. Alexander. "Cardiovascular change and hypothalamic norepinephrine release in response to environmental stress." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 264, no. 4 (April 1, 1993): R784—R789. http://dx.doi.org/10.1152/ajpregu.1993.264.4.r784.
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The major objective of this study was to compare the magnitude and duration of cardiovascular (CV) responses to acute environmental stresses with the associated patterns of noradrenergic activity in the paraventricular nucleus (PVN) and posterior nucleus (PH) of the hypothalamus. Simultaneous microdialysis samples of extracellular norepinephrine (NE) were collected at 5-min intervals from PVN and PH and the CV responses were recorded before, during, and for 15 min after acute shaker (cage oscillation) stress or inhalation of ether vapor in freely moving rats. Five minutes of shaker stress, 60 and 150 cycles/min, elicited pressor responses coupled with increases in dialysate NE from both PVN and PH in a frequency-dependent manner. Tachycardia occurred at 150 but not 60 cycles/min. Ten minutes after 60 cycles/min and 15 min after 150 cycles/min, NE efflux in PH was still increased, whereas in PVN it returned to control as had arterial pressure and heart rate. Ether vapor elicited a transient CV response but a continuing efflux of NE in PH and PVN. Urethan anesthesia raised baseline values of dialysate NE in PH and PVN but significantly attenuated cardiovascular and dialysate NE responses to shaker stress. We conclude that acute environmental stress simultaneously elicits CV responses and the efflux of NE from PVN and PH but, during or after stress, CV values may return to control levels while NE efflux remains elevated in PVN and/or PH.
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Kaombe, Divina D., Yanhong Du, and Michael J. Lewis. "Mineral partitioning in milk and milk permeates at high temperature." Journal of Dairy Research 79, no. 1 (September 13, 2011): 1–6. http://dx.doi.org/10.1017/s0022029911000616.
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The soluble phase of milk was separated at 20 and 80°C using ultrafiltration. The resulting permeates were then subjected to further ultrafiltration and dialysis at close to these two temperatures. It was found that pH, Ca2+ and soluble Ca decreased as the separation temperature increased both in original UF permeates and in dialysates obtained from these permeates, but P decreased only slightly. The major reason for these changes was due to the precipitation of calcium phosphate/citrate complexes onto the casein micelle with concomitant release of H+. The pH of both permeates and dialysates from milk at 20°C were slightly higher than for milk. When UF permeates collected at 20 and 80°C, were each dialysed at both these temperatures, the dialysate collected at 80°C showed much less temperature dependence for pH and ionic calcium compared with that collected at 20°C. This is in contrast to milk, which shows considerable temperature dependence for pH and ionic calcium. Further experiments revealed that the pH and Ca2+ concentration of permeates showed high temperature dependence above the temperature at which they were separated, but a much lower temperature dependence below that temperature. These findings suggest that dialysis and UF of milk at high temperature provide the best means yet for estimating the pH and ionic calcium of milk at that temperature.
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Vu, Lien H., John A. Kellum, William J. Federspiel, and Matthew E. Cove. "Carbon dioxide removal using low bicarbonate dialysis in rodents." Perfusion 34, no. 7 (April 2, 2019): 578–83. http://dx.doi.org/10.1177/0267659119839284.
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Background: Extracorporeal carbon dioxide removal may be used to manage hypercapnia, but compared to dialysis, it’s not widely available. A recent in vitro study showed that dialysis with low bicarbonate dialysates removes CO2. Objective: To show that bicarbonate dialysis removes CO2 in an animal model to validate in-vitro findings and quantify the effect on arterial pH. Methods: Male Sprague-Dawley hypercapnic rats were dialyzed with either a conventional dialysate (PrismasolTM) or a bicarbonate-free dialysate (Bicarb0). The effect of dialysis on standard blood gases and electrolytes was measured. Results: Partial pressure of CO2 and bicarbonate concentration in blood decreased significantly after exposure to Bicarb0 compared to PrismasolTM (filter outflow values 12.8 vs 81.1 mmHg; p < 0.01 for CO2 and 3.5 vs 22.0 mmol/L; p < 0.01 for bicarbonate). Total CO2 content of blood was reduced by 459 mL/L during dialysis with Bicarb0 (filter inflow 546 ± 91 vs filter outflow 87 ± 52 mL/L; p < 0.01), but was not significantly reduced with PrismasolTM. Conclusions: Bicarbonate dialysis removes CO2 at rates comparable to existing low-flow ECCO2R.
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La Milia, Vincenzo, Monica Limardo, Monica Crepaldi, and Francesco Locatelli. "Effects of Ionized Sodium Concentrations on Ultrafiltration Rate in Peritoneal Dialysis Using Lactate and Lactate/Bicarbonate Solutions." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 29, no. 2 (March 2009): 158–62. http://dx.doi.org/10.1177/089686080902900209.
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Objective To investigate the possible effects of different concentrations of ionized sodium (NaI) on peritoneal ultrafiltration (UF) rate using lactate (Lac) and lactate/bicarbonate (Lac/Bic) dialysis solutions. Design Two random consecutive (after an interval of 48 hours) peritoneal equilibration tests (PETs) were performed in 13 patients (4 males and 9 females) on regular continuous ambulatory peritoneal dialysis (PD) treatment for at least 3 months. Two different PD solutions containing anhydrous glucose 3.86% were used: a 40 mmol/L Lac solution and a 15/25 mmol/L mixed Lac/Bic solution. Concentrations of total sodium (NaT) and NaI were measured by flame photometer and direct ion-selective electrode respectively. Results Dialysate concentrations of NaT were not different during PETs using Lac and Lac/Bic. Dialysate concentrations of NaI in fresh PD solutions were different (133.3 ± 1.7 vs 128.2 ± 3.9 mmol, p < 0.0001); however, these differences disappeared just after the end of the infusion of the fresh solutions. Peritoneal UF rate was not significantly different during PETs using Lac versus Lac/Bic (609 ± 301 mL vs 542 ± 362 mL). The dialysate-to-plasma ratios of sodium concentrations at 60 minutes of the PETs (which are expressions of free water transport) were not different using Lac versus Lac/Bic (0.89 ± 0.04 vs 0.89 ± 0.04 respectively, p = 0.96). All the other classical parameters of the PET were not different between Lac and Lac/Bic. Conclusions The higher dialysate concentrations of NaI due to lower dialysate pH and consequently the higher effective osmolality of the fresh Lac PD solutions did not influence peritoneal UF rate, probably because of the fast reduction of NaI concentrations due to rapid correction of dialysate pH at the end of the infusion of Lac solutions into the peritoneal cavity.
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Douvdevani, Amos, Jayson Rapoport, Aviva Konforti, Moshe Zlotnik, and Cidio Chaimovitz. "The Effect of Peritoneal Dialysis Fluid on the Release of Il-113 and Tnfa by Macrophages/Monocytes." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 13, no. 2 (April 1993): 112–17. http://dx.doi.org/10.1177/089686089301300206.
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Objective To study the effect of dialysis fluid on the release of interleukin-1β (IL-1β) and tumor necrosis factor (TNFα) by peritoneal macrophages (PM) and peripheral blood mononuclear cells (MNC), and the time course and factors involved in this effect Design PM and MNC were incubated for various periods with Dianeal itself, or Dianeal of varying pH and composition.IL-1 β was measured by radioimmunoassay and TNFα by cytotoxicity assay. Patients PM were obtained by centrifugation of dialysis effluent from 3 continuous ambulatory peritoneal dialysis (CAPD) patients. MNC were obtained from healthy volunteers. Results Dialysis fluid inhibited the release of both cytokines. Indomethacin had no effect on the inhibition of TNFα release caused by dialysis fluid. Thus prostaglandins are not involved in this inhibition. Solutions of pH 5.2 and high lactate concentration caused an identical inhibition to that caused by dialysate, whereas the presence or absence of glucose had no effect. Thus it seems that pH and lactate are the important inhibitory factors. Time course studies showed that the inhibition of TNFα release was substantial after only 15 minutes of incubation with dialysate, whereas the inhibition of IL-1 β became significant only after 60 minutes of incubation. Conclusions Even though dialysate pH rises within 15–30 minutes after instillation into the abdomen, the initial low pH present for only a short time could have a significant effect on TNFα release by peritoneal macrophages, and thus on their ability to mount a normal inflammatory response. Lactate also has a significant inhibitory role. It is suggested that commercial dialysis solutions should have a pH of 7. Oandthata physiological buffer other than lactate be used.
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McCormick, Brendan B., Salim Mujais, Francine Poirier, Nicole Page, and Susan Lavoie. "Metabolic Effects of Incremental Doses of Intraperitoneal Amino Acids on Automated Peritoneal Dialysis." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 30, no. 2 (March 2010): 201–7. http://dx.doi.org/10.3747/pdi.2009.00040.
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BackgroundThe use of amino acid (AA) dialysate to ameliorate protein-energy malnutrition has been limited by adverse metabolic effects.ObjectiveWe undertook this study to examine the acute metabolic effects of escalating doses of AAs delivered with lactate/bicarbonate dialysate on automated peritoneal dialysis (APD).Patients and Methods12 APD patients were treated with conventional lactate-buffered dialysate (week 1), followed by lactate/bicarbonate-buffered dialysate (week 2), then 2 – 2.5 L 1.1% AA solution were added (week 3), and then an additional 2 – 2.5 L 1.1% AA were added (week 4). The primary outcomes were change in serum bicarbonate and pH, change in protein catabolic rate (PCR), and change in normalized ultrafiltration (milliliters/gram of carbohydrate infused).ResultsSerum bicarbonate rose from week 1 to week 2 (28.9 ± 3.2 vs 26.9 ± 4.1 mmol/L, p = 0.03). Addition of one bag of AAs led to a decline in plasma bicarbonate (26.9 ± 2.1 vs 28.9 ± 3.2 mmol/L, p < 0.01), which was further magnified by the addition of the second bag of AAs (23.8 ± 2.7 vs 26.9 ± 2.1 mmol/L, p < 0.01). Serum bicarbonate fell significantly by week 4 compared to week 1 (23.8 ± 2.7 vs 26.9 ± 3.2 mmol/L, p < 0.01) although there was no significant change in venous pH or PCR when week 4 was compared to week 1. Normalized ultrafiltration was stable for the first 3 weeks but rose significantly in week 4 compared to week 1 (5.32 ± 2.30 vs 4.14 ± 1.58 mL/g, p = 0.03).ConclusionsHigher doses of AAs mixed with newer bicarbonate/lactate dialysate on APD result in a small decrease in serum bicarbonate but improved normalized ultrafiltration. This merits further study as both a nutritional supplement and a glucose-sparing strategy.
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Parikova, Alena, Dirk G. Struijk, Machteld M. Zweers, Monique Langedijk, Natalie Schouten, Nicole van den Berg, Saskia Duis, and Raymond T. Krediet. "Does the Biocompatibility of the Peritoneal Dialysis Solution Matter in Assessment of Peritoneal Function?" Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 27, no. 6 (November 2007): 691–96. http://dx.doi.org/10.1177/089686080702700617.
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Background Peritoneal function tests are performed in peritoneal dialysis (PD) patients to characterize peritoneal membrane status. A low pH/high glucose degradation product (GDP) dialysis solution is used as the test solution. The objective of the present study was to compare a 3.86% glucose, low pH/high GDP dialysis solution (pH 5.5) with a 3.86% glucose, normal pH/low GDP dialysis solution (pH 7.4) in assessments of peritoneal membrane function. Methods Two standard peritoneal permeability analyses (SPA) were performed in 10 stable PD patients within 2 weeks. One SPA was done with the 3.86% low pH/high GDP solution, and the other with the 3.86% normal pH/low GDP solution. The sequence of the two tests was randomized. Results Fluid transport parameters and glucose absorption were not different between the two groups. No differences were found for the mass transfer area coefficients (MTACs) of low molecular weight solutes calculated over the whole dwell. However, MTAC urea in the first hour of the dwell was higher in the test done with low pH/high GDP dialysate, suggesting more peritoneal vasodilation. No difference was found in protein clearances. Sodium sieving at multiple time points during the dwell was similar with the two solutions. Conclusion The results obtained with the glucose-containing normal pH/low GDP dialysis solution were similar to those obtained with the glucose-containing low pH/high GDP dialysate in assessments of peritoneal membrane function.
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Douvdevani, A., J. Rapoport, A. Konforty, R. Yulzari, A. Moran, and C. Chaimovitz. "Intracellular acidification mediates the inhibitory effect of peritoneal dialysate on peritoneal macrophages." Journal of the American Society of Nephrology 6, no. 2 (August 1995): 207–13. http://dx.doi.org/10.1681/asn.v62207.
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Commercial peritoneal dialysis solution (CDS) is known to have a detrimental effect on the capacity of peritoneal macrophages (PM phi) to kill bacteria and produce acute phase cytokines. This cytotoxic effect is largely caused by the low pH of CDS. Because the cytoplasmic pH (pHi) is an important determinant of cellular function, the effect of CDS on the pHi of PM phi from continuous ambulatory peritoneal dialysis patients was studied. The pHi of PM phi was measured fluorometrically in N-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES)-buffered salt solution (HBSS) or CDS at pH values of 5.3, 6.5, and 7.0, values that represent the pH existing in dialysate during the first 30 min of dwell time. For any given pH of the experimental medium, the pHi was always more acidic in CDS than in HBSS. When PM phi were incubated with a lactate-containing HBSS, a cellular acidification was observed that was similar to that attained by exposure to CDS at the same pH. This supports the hypothesis that the decrease in pHi was due to the influx of lactic acid from the CDS into the PM phi. In order to demonstrate a causal association between the CDS-induced cellular acidification and a defect in phagocytosis and cytokine production, these functions were studied after pHi clamping by means of K+/nigericin. It was found that clamping pHi to values below 6.5 led to a markedly reduced tumor necrosis factor-alpha production and phagocytosis. However, at values of pHi > 6.5, these functions were normal. (ABSTRACT TRUNCATED AT 250 WORDS)
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MacLean, David A., Virginia A. Imadojemu, and Lawrence I. Sinoway. "Interstitial pH, K+, lactate, and phosphate determined with MSNA during exercise in humans." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 278, no. 3 (March 1, 2000): R563—R571. http://dx.doi.org/10.1152/ajpregu.2000.278.3.r563.
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The purpose of the present study was to use the microdialysis technique to simultaneously measure the interstitial concentrations of several putative stimulators of the exercise pressor reflex during 5 min of intermittent static quadriceps exercise in humans ( n = 7). Exercise resulted in approximately a threefold ( P < 0.05) increase in muscle sympathetic nerve activity (MSNA) and 13 ± 3 beats/min ( P < 0.05) and 20 ± 2 mmHg ( P < 0.05) increases in heart rate and blood pressure, respectively. During recovery, all reflex responses quickly returned to baseline. Interstitial lactate levels were increased ( P < 0.05) from rest (1.1 ± 0.1 mM) to exercise (1.6 ± 0.2 mM) and were further increased ( P < 0.05) during recovery (2.0 ± 0.2 mM). Dialysate phosphate concentrations were 0.55 ± 0.04, 0.71 ± 0.05, and 0.48 ± 0.03 mM during rest, exercise, and recovery, respectively, and were significantly elevated during exercise. At the onset of exercise, dialysate K+ levels rose rapidly above resting values (4.2 ± 0.1 meq/l) and continued to increase during the exercise bout. After 5 min of contractions, dialysate K+ levels had peaked with an increase ( P < 0.05) of 0.6 ± 0.1 meq/l and subsequently decreased during recovery, not being different from rest after 3 min. In contrast, H+ concentrations rapidly decreased ( P < 0.05) from resting levels (69.4 ± 3.7 nM) during quadriceps exercise and continued to decrease with a mean decline ( P < 0.05) of 16.7 ± 3.8 nM being achieved after 5 min. During recovery, H+ concentrations rapidly increased and were not significantly different from baseline after 1 min. This study represents the first time that skeletal muscle interstitial pH, K+, lactate, and phosphate have been measured in conjunction with MSNA, heart rate, and blood pressure during intermittent static quadriceps exercise in humans. These data suggest that interstitial K+ and phosphate, but not lactate and H+, may contribute to the stimulation of the exercise pressor reflex.
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Shaw, L. M., R. Altman, B. C. Thompson, and L. Fields. "Factors affecting the binding of disopyramide to serum proteins." Clinical Chemistry 31, no. 4 (April 1, 1985): 616–19. http://dx.doi.org/10.1093/clinchem/31.4.616.
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Abstract We investigated the influence of the following factors on the binding of disopyramide to serum proteins: method of drug quantification [enzyme immunoassay (EMIT) compared with liquid chromatography (HPLC)], separation technique (ultrafiltration vs equilibrium dialysis), temperature, pH, and total concentration of disopyramide. EMIT and HPLC measurements of disopyramide in ultrafiltrates prepared from 50 sera agreed well: EMIT = 1.046 HPLC + 0.042, (r = 0.928, SEE = 0.04 mg/L). Free disopyramide concentrations in ultrafiltrates of dialyzed sera were similar to those measured in the corresponding dialysates by the EMIT method for 30 patients' sera: ultrafiltrate of serum retentate = 1.053 dialysate + 0.042. Concentrations of free [14C]disopyramide were little affected by temperature. The concentration of free disopyramide decreased as the pH was increased from 7.0 to 7.8. The concentration of free disopyramide, as determined by ultrafiltration, is strongly and directly related to total drug concentration. In the sera of 50 cardiac patients receiving chronic therapy with disopyramide and with total disopyramide concentrations of 0.5 to 5.8 mg/L, the proportion of free disopyramide ranged from 16 to 54%.
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Wieczorowska–Tobis, Katarzyna, Renata Brelinska, Janusz Witowski, Jutta Passlick–Deetjen, Thomas P. Schaub, Holger Schilling, and Andrzej Breborowicz. "Evidence for Less Irritation to the Peritoneal Membrane in Rats Dialyzed with Solutions Low in Glucose Degradation Products." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 24, no. 1 (January 2004): 48–57. http://dx.doi.org/10.1177/089686080402400105.
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Background Acidic pH and the presence of glucose degradation products (GDP) are believed to compromise the biocompatibility of peritoneal dialysis fluids (PDF). The present study examines the effects of long-term exposure to GDP and low pH by comparing conventional PDF and a new, neutral pH, low GDP solution. Methods All experiments were performed using a chronic infusion model of dialysis in nonuremic rats. The animals were treated for 6 weeks with 2 daily injections of 4.25% glucose-containing PDF. The following PDF were tested: CAPD3 (single-chamber bag, low pH, high GDP), CAPD3 pH 7.4 (single-chamber bag, neutral pH, high GDP), CAPD3-Balance (double-chamber bag, neutral pH, low GDP). All test solutions were obtained from Fresenius Medical Care, Bad Homburg, Germany. Results After 6 weeks of exposure, peritoneal permeability to water, urea, creatinine, glucose, and sodium, assessed by peritoneal equilibration test, was similar in all groups. However, compared to other PDF, dialysis with CAPD3-Balance was associated with reduced concentrations of protein and hyaluronan in the dialysate, decreased peritoneal eosinophilia, and reduced dialysate levels of chemokines CCL2/MCP-1 and CCL5/RANTES. Morphologic changes in the peritoneal membrane of CAPD3-Balance-treated animals were much less pronounced and included reduced vascular density, preservation of the mesothelial monolayer and intercellular junction, and no reduplication of the submesothelial basement membrane. Conclusions A new generation of PDF with physiologic pH and low GDP level produce less irritation to the peritoneal membrane and better preserve its structural integrity. This effect seems to be related predominantly to minimized GDP concentrations.
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Ahrenholz, P., R. E. Winkler, W. Ramlow, M. Tiess, and O. Thews. "On-Line Hemodiafiltration with Pre- and Postdilution: Impact on the Acid-Base Status." International Journal of Artificial Organs 21, no. 6 (June 1998): 321–27. http://dx.doi.org/10.1177/039139889802100601.
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With on-line formation of the substitution fluid, high substitution rates in predilution (PRD) and postdilution (POD) can be obtained (Fresenius 4008 On-Line HDF, Gambro AK 100 Ultra). The substitution fluid is branched off from the dialysate produced by the dialysate delivery system of the HDF machine. Under these conditions it is desirable to consider the effect of the different treatment modes on the acid-base status. Using Fresenius 4008 On-Line HDF machines, ESRD-patients were treated alternately with high-flux hemodialysis (HD), postdilution HDF (POD-HDF) and predilution HDF (PRD-HDF), while all other treatment parameters were kept constant, in particular the bicarbonate dialysate concentration. Plasma-HCO3, - pH and -pCO2 were measured and compared with the results of a multicompartment bicarbonate model developed by Thews. Also plasma-pO2 and K+ were measured. The results showed no significant differences between HD, POD- and PRD-HDF. Acidosis was corrected effectively and no excessive compensation of the acid-base disturbance was observed.
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Bunchman, Timothy E., and Sudarshan H. Ballal. "Treatment of Inflow Pain by pH Adjustment of Dialysate in Peritoneal Dialysis." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 11, no. 2 (April 1991): 179–80. http://dx.doi.org/10.1177/089686089101100216.
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Park, Min Sun, Olof Heimbürger, Jacek Waniewski, Andrzej Werynski, Hi Bahl Lee, Jonas Bergström, and Bengt Lindholm. "The Effect of Dialysate Acidity on Peritoneal Solute Transport in the Rat." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 15, no. 4 (October 1995): 312–19. http://dx.doi.org/10.1177/089686089501500406.
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Objective To investigate the possible effect of unphysiologically low pH in dialysis fluid on peritoneal transport. Design A 4-hour single-cycle experimental session of peritoneal dialysis was performed in six 5prague-Dawley rats using Dianeal 3.86% solution modified by adding 5 mmol/L of sodium hydroxide, neutral pH solution (NpH5) (pH 7.4). The intraperitoneal volume (V D) and peritoneal bulkfluid reabsorption (aa) were calculated using a marker, 1311–labeled human serum albumin (RI5A). The diffusive mass transport coefficient (KBD) as well as sieving coefficient (5) for glucose, urea, sodium, and potassium were calculated using the Babb-Randerson-Farrell model. The same study was performed in seven rats using Dianeal 3.86% solution, acidic pH solution (ApH5) (pH 5.7) to provide control values. Results The dialysate pH was stable with NpH5; 45 min after the infusion of ApH5 it increased rapidly and reached the physiological value 7.4. Dialysate volume and KBD values for sodium and potassium with NpH5 were significantly higher than with ApH5, while the KBD values for glucose and urea did not differ between the two solutions. 5 values for sodium and urea did not differ between the two solutions, while the values for glucose and potassium with NpH5 were significantly higher and lower, respectively, than the values with ApH5 (0.92±1.04 vs 0.04±0.63 and 0.56±060 vs 1.15±0.39, p < 0.05). The absorption of glucose from the dialysis solution expressed as a percentage of the initial amount of dialysate glucose was significantly lower with NpH5 than with ApH5 at 30 min (17.3±1.7% vs 29.7±2.0%, p < 0.05). Conclusion We conclude that the peritoneal transport of fluid and small solutes might to some extent be influenced by the acidity of the dialysis solution. The vasodilatory effect of acidic dialysis solution might be the most important mechanism for these differences. However, a larger KBD value and a lower 5 value for potassium and higher 5 values for glucose during dialysis with the neutral dialysis solution may indicate that transport mechanisms other than simple passive transport are involved in peritoneal transport for glucose and electrolytes.
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Wieczorowska–Tobis, Katarzyna, Arkadiusz Styszynski, Andrzej Breborowicz, and Dimitrios G. Oreopoulos. "Comparison of the Biocompatibility of Phosphate-Buffered Saline Alone, Phosphate-Buffered Saline Supplemented with Glucose, and Dianeal 3.86%." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 21, no. 3_suppl (December 2001): 362–64. http://dx.doi.org/10.1177/089686080102103s68.
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Objective We compared the effects of intraperitoneal infusion of phosphate-buffered saline (PBS, pH 7.4), of PBS supplemented with 3.86% glucose (G), and of standard dialysis solution [Dianeal 3.86%: Baxter Healthcare Corporation, Deerfield, IL, U.S.A. (D)] on intraperitoneal inflammation in dialyzed rats. Methods After catheter implantation, rats were infused on day 1 with PBS, on day 3 with PBS+G, on day 5 with D, and on day 7 again with PBS (PBS-2). After a 4-hour dwell, dialysate samples were collected and analyzed. Results All dialysate parameters studied [dialysate cell count, neutrophil:macrophage ratio (Ne:Ma), and total protein], except tumor necrosis factor alpha (TNFα), were comparable during both PBS infusions. During dialysis with PBS+G, the inflammatory response was suppressed as compared with the first dialysis with PBS (cell count, p < 0.001; Ne:Ma, p < 0.05; TNFα, p < 0.001; total protein, p < 0.001). During dialysis with D, peritoneal inflammatory parameters were further suppressed (cell count, p < 0.001 vs PBS and p < 0.01 vs PBS+G; Ne:Ma, p < 0.001 vs PBS and p < 0.05 vs PBS+G; TNFα, p < 0.001 vs PBS and p < 0.001 vs PBS+G; total protein, p < 0.001 vs PBS and p < 0.01 vs PBS+G). Conclusions Hypertonicity of the dialysis fluid suppresses intraperitoneal inflammatory parameters in rats. The suppression was even more severe when Dianeal 3.86% was used. That finding could be due to the low pH and presence of GDPs in the fluid.
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Kashem, Abul, Yasuo Nomoto, Ryoji Tanabe, Makoto Nishina, Haruko Endoh, Keiko Nakajima, Masayuki Endoh, Hideto Sakai, and Hiroe Nakazawa. "The Effect of Dialysate Glucose on Phagocyte Superoxide Generation in Capd Patients." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 18, no. 1 (January 1998): 52–59. http://dx.doi.org/10.1177/089686089801800106.
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Objective In the present study, we investigated the influence of dialysate glucose on superoxide (02) generation by peripheral and peritoneal phagocytes in continuous ambulatory peritoneal dialysis (CAPD) patients. Design Peripheral polymorphonuclear leukocytes (PMNL) and mononuclear leukocytes (MNL), and peritoneal cells were isolated from peripheral blood and peritoneal effluents, respectively, and their oxidative metabolism was assessed by measuring 02 generation after stimulation with a soluble stimulant [phorbol myristate acetate (PMA), 1 mg/mL, Sigma Chemical, St. Louis, MO, U.S.A.] using the chemiluminescence method. Dialysate glucose effect on 02 generation was also studied in vitro by exposing peripheral PMNL and MNL from healthy controls to peritoneal dialysis fluid (PDF) containing glucose or amino acids at a neutral pH for different time periods. Results The amount of 02 generation by both peripheral and peritoneal phagocytes in CAPD patients was significantly higher than that in the control, and the response was greater in patients who were dialyzed with high glucose dialysate than those using low glucose dialysate. In an in vitro study, all incubated cells, except the control, showed suppression of 02 generation in the early dwell time (2 hr), and subsequently showed increased responses (peaking at 6 hr), although lower in degree than those observed in vivo. In contrast, amino acid-based PDF exhibited no such effect on 02 generation at identical pH with similar or lower osmolality. Furthermore, the respective increased or decreased oxidative responses with the increased or decreased PDF glucose concentrations in the same patient confirmed the positive effect of PDF glucose on phagocyte 02 generation. Conclusion It is suggested that increased 02 generation by peritoneal and circulating phagocytes in CAPD patients is at least partly due to the enhancement of hexose monophosphate shunt activity by increasing glucose metabolism in phagocytes, and the increased 02 generation might be involved in long-term complications of CAPD. Therefore, a suitable alternative osmotic agent is needed to provide a more physiological environment to minimize the adverse effects of glucose on cell functions.
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Khaldi, Ahmad, Alois Zauner, Michael Reinert, John J. Woodward, and M. Ross Bullock. "Measurement of Nitric Oxide and Brain Tissue Oxygen Tension in Patients after Severe Subarachnoid Hemorrhage." Neurosurgery 49, no. 1 (July 1, 2001): 33–40. http://dx.doi.org/10.1097/00006123-200107000-00005.
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Abstract OBJECTIVE Nitric oxide (NO), one of the most powerful endogenous vasodilators, is thought to play a major role in the development of delayed vasospasm in patients with subarachnoid hemorrhage (SAH). However, the role of the production of cerebral NO in patients with SAH is not known. In other SAH studies, NO metabolites such as nitrite and nitrate have been demonstrated to be decreased in cerebrospinal fluid and in plasma. METHODS In this study, a microdialysis probe was used, along with a multiparameter sensor, to measure NO metabolites, brain tissue oxygen tension, brain tissue carbon dioxide tension, and pH in the cortex of patients with severe SAH who were at risk for developing secondary brain damage and vasospasm. NO metabolites, glucose, and lactate were analyzed in the dialysates to determine the time course of NO metabolite changes and to test the interrelationship between the analytes and clinical variables. RESULTS Brain tissue oxygen tension was strongly correlated to dialysate nitrate and nitrite (r2 = 0.326;P < 0.001); however, no correlation was noted between brain tissue oxygen tension and NO metabolites in cerebrospinal fluid (r2 = 0.018;P = 0.734). No significant correlation between NO production, brain tissue carbon dioxide tension, and dialysate glucose and lactate was observed. CONCLUSION Cerebral ischemia and compromised substrate delivery are often responsible for high morbidity rates and poor outcomes after SAH. The relationship between brain tissue oxygen and cerebral NO metabolites that we demonstrate suggests that substrate delivery and NO are linked in the pathophysiology of vasospasm after SAH.
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Cho, Yeoungjee, David W. Johnson, David A. Vesey, Carmel M. Hawley, Elaine M. Pascoe, Margaret Clarke, and Nicholas Topley. "Higher Dialysate Matrix Metalloproteinase-2 Levels are Associated with Peritoneal Membrane Dysfunction." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 36, no. 1 (January 2016): 16–25. http://dx.doi.org/10.3747/pdi.2013.00274.
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♦ Background Peritoneal dialysis (PD) patients develop progressive and cumulative peritoneal injury with longer time spent on PD. The present study aimed to a) describe the trend of peritoneal injury biomarkers, matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1), in incident PD patients, b) to explore the capacity of dialysate MMP-2 to predict peritoneal solute transport rate (PSTR) and peritonitis, and c) to evaluate the influence of neutral pH, low glucose degradation product (GDP) PD solution on these outcomes. ♦ Methods The study included 178 participants from the balANZ trial who had at least 1 stored dialysate sample. Changes in PSTR and peritonitis were primary outcome measures, and the utility of MMP-2 in predicting these outcomes was analyzed using multilevel linear regression and multilevel Poisson regression, respectively. ♦Results Significant linear increases in dialysate MMP-2 and TIMP-1 concentrations were observed ( p < 0.001), but neither was affected by the type of PD solutions received (MMP-2: p = 0.07; TIMP-1: p = 0.63). An increase in PSTR from baseline was associated with higher levels of MMP-2 ( p = 0.02), and the use of standard solutions over longer PD duration ( p = 0.001). The risk of peritonitis was independently predicted by higher dialysate MMP-2 levels (incidence rate ratio [IRR] per ng/mL 1.01, 95% confidence interval [CI] 1.005 – 1.02, p = 0.002) and use of standard solutions (Biocompatible solution: IRR 0.45, 95% CI 0.24 – 0.85, p = 0.01). ♦ Conclusion Dialysate MMP-2 and TIMP-1 concentrations increased with longer PD duration. Higher MMP-2 levels were associated with faster PSTR and future peritonitis risk. Administration of biocompatible solutions exerted no significant effect on dialysate levels of MMP-2 or TIMP-1, but did counteract the increase in PSTR and the risk of peritonitis associated with the use of standard PD solutions. This is the first longitudinal study to examine the clinical utility of MMP-2 as a predictor of patient-level outcomes.
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Curtis, J. R., and B. Sampson. "Aluminium Kinetics during Haemodialysis with the Redy 2000 Sorbsystem." International Journal of Artificial Organs 12, no. 11 (November 1989): 683–87. http://dx.doi.org/10.1177/039139888901201103.
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Aluminium kinetics of the Redy 2000 Sorbsystem using D3260 cartridges and the latest pre-treatment protocol have been studied in vitro and in vivo. In 7 patients, aluminium kinetics were studied during haemodialysis using the Redy 2000 Sorbysystem, D3260 cartridges, S557 acetate concentrate and Gambro hollow fibre dialyser (cuprophane 120M). The same patients were also studied during conventional haemodialysis using the Gambro AK10 proportionating system with acetate dialysate and Gambro hollow fibre dialyser (cuprophane 120M). There was no significant rise in plasma aluminium concentration during dialysis on the Redy 2000 Sorbsystem. The post-dialysis plasma aluminium concentrations were significantly higher after conventional haemodialysis, however, and the explanation for this is not clear but is not accounted for by differences in the degree of ultrafiltration during the studies. A significant rise in dialysate aluminium concentration was observed after 4 hours of dialysis on the Redy 2000 Sorbsystem. The manufacturer's ammonia test papers appear to be too insensitive as indicators of cartridge exhaustion and dialysate pH may be better. The D3260 cartridges should be used for a maximum of 4 hours only. Further long-term studies of aluminium kinetics using this system are justified.
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Nataatmadja, Melissa, Yeoungjee Cho, Elaine M. Pascoe, Darsy Darssan, Carmel M. Hawley, and David W. Johnson. "Association between Peritoneal Glucose Exposure and Peritonitis in Peritoneal Dialysis Patients: TheBalANZ Trial." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 37, no. 4 (July 2017): 407–13. http://dx.doi.org/10.3747/pdi.2016.00263.
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BackgroundGlucose is the primary osmotic medium used in most peritoneal dialysis (PD) solutions, and exposure to glucose has been shown to exert detrimental effects both locally, at the peritoneal membrane, and systemically. Moreover, high dialysate glucose exposure may predispose patients to an increased risk of peritonitis, perhaps as a result of impaired host defences, vascular disease, and damage to the peritoneal membrane.MethodsIn this post-hoc analysis of a multicenter, multinational, open-label randomized controlled trial of neutral pH, low-glucose degradation product (GDP) versus conventional PD solutions ( balANZ trial), the relationship between peritonitis rates of low (< 123.1 g/day) versus high (≥ 123.1 g/day) dialysate glucose exposure was evaluated in 177 incident PD patients over a 2-year study period.ResultsPeritonitis rates were 0.44 episodes per patient-year in the low-glucose exposure group and 0.31 episodes per patient-year in the high-glucose exposure group, (incidence rate ratio [IRR] 0.69, p = 0.09). There was no significant association between dialysate glucose exposure and peritonitis-free survival on univariable analysis (high glucose exposure hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.40 –1.08) or on multivariable analysis (adjusted HR 0.64, 95% CI 0.39 – 1.05). Moreover, there was no relationship between peritoneal glucose exposure and type of organism causing peritonitis. Physician-rated severity of first peritonitis episodes was similar between groups, as was rate and duration of hospital admission.ConclusionsOverall, this study did not identify an association between peritoneal dialysate glucose exposure and peritonitis occurrence, severity, hospitalization, or outcomes. A further large-scale, prospective, randomized controlled trial evaluating patient-level outcomes is merited.
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Waniewski, J., O. Heimbürger, A. Werynski, and B. Lindholm. "Simple Models for Fluid Transport during Peritoneal Dialysis." International Journal of Artificial Organs 19, no. 8 (August 1996): 455–66. http://dx.doi.org/10.1177/039139889601900806.
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Peritoneal fluid transport can be predicted using different simplified formulas. To evaluate three such models, fluid transport was studied in 38 single six hour dwell studies using standard glucose 1.36% (n=9), 2.27% (n=9) and 3.86% (n=20) dialysis fluids as well as amino acid 2.70% fluid (n=8) in 33 patients on continuous ambulatory peritoneal dialysis (CAPD). Dialysate volume and the peritoneal absorption rate were measured using radioiodinated serum albumin (RISA) as a marker. The dialysate volume over dwell time curves were examined using three mathematical models of fluid transport for solutions with a crystalloid osmotic agent: Model P based on phenomenologically derived exponential function of time (Pyle, 1981), Model OS based on linear relationship between the rate of net volume change, Qv, to the difference of osmolality in dialysate and blood, and Model G based on linear relationship between Qv and the difference of glucose concentration in dialysate and blood. All these models provided a good description of the measured dialysate volume over time curves, however the descriptions with Models OS and G for glucose 3.86% fluid were slightly but significantly less precise. The coefficients of Model OS were stable in time, but the coefficients of Model G and P dependend in general on the time period used for their estimation, especially for glucose 3.86% dialysis fluid. The evaluation of dwell studies with solutions containing amino acid 2.70% (instead of glucose) as osmotic agent, using Model OS and P, showed that the transport coefficients were stable in time and both models provided equally precise descriptions. These results suggested that all three models can be used but models P and OS can be preferred for pratical applications such as predictions of fluid transport with alternative cristalloid osmotic agents. Furthermore, we found that the peritoneal barrier for fluid transport may change transiently during exchanges with the standard glucose - based dialysis fuid, whereas such changes were not observed with the amino acid-based fluid. This discrepancy may be due to a different composition of the dialysis fluids, including osmotic agent, buffer and pH.
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Moncrief, Jack, Robert Popovich, Everett Simmons, and Zhengzhi He. "Catheter Obstruction with Omental Wrap Stimulated by Dialysate Exposure." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 13, no. 2_suppl (January 1993): 127–29. http://dx.doi.org/10.1177/089686089301302s34.
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A new Implantation technique and catheter design (Moncrlef-Popovlch Catheter) were tested in the continuous ambulatory peritoneal dialysis (CAPO) dog model. With this technique the catheter distal (external) segment was Implanted in a subcutaneous tunnel for 4–6 weeks. Therefore, no irrigation of exposure to dialysate was present. Secondary exteriorization and irrigation (CAPO exchanges) demonstrated no episodes of primary catheter obstruction. Fifteen mongrel female dogs had 30 catheters implanted; 2 catheters simultaneously in each dog. One catheter was implanted with the interabdominal segments in the pelvis and the second interabdominal segment directed upward In direct contact with the omentum. Following initial irrigation, all catheters were patent, but within 24–48 hours all upwardly directed catheters were obstructed. Nine of the 15 downwardly directed catheters became obstructed by omentum wrapping around the catheter within 5 days. Preliminary studies have failed to demonstrate the cause of this “omental stimulation,” which occurs with peritoneal contact with fresh dialysate. Possible explanations include pH, osmolality, flow direction, volume, vasodilator effect of osmols or lactate, and glucose, among others. This effect needs study, and this model would allow evaluation of improvements in the biocompatibility of dialysis fluids.
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Sonikian, M., J. Gogusev, J. Zingraff, S. Loric, B. Quednau, G. Bessou, W. Siffert, T. B. Drüeke, H. P. Reusch, and F. C. Luft. "Potential effect of metabolic acidosis on beta 2-microglobulin generation: in vivo and in vitro studies." Journal of the American Society of Nephrology 7, no. 2 (February 1996): 350–56. http://dx.doi.org/10.1681/asn.v72350.
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Beta 2-microglobulin (beta 2M) is responsible for dialysis-associated amyloidosis. Level of beta 2M in plasma increase during chronic renal failure; however, retention does not appear to be the sole mechanism responsible. The effect of metabolic acidosis on beta 2M production was examined. Thirty-six patients with stable chronic renal insufficiency, 12 uremic patients before their first dialysis, 8 hemodialysis patients who were assigned to acetate or bicarbonate dialysate and then crossed over to the alternative regimen, and 6 normal subjects given NH4Cl to initiate metabolic acidosis were studied. In vitro studies in the human myeloid cell line U 937 were also performed. beta 2M protein was measured with ELISA, beta 2M mRNA was measured with reverse transcription polymerase chain reaction, and the U 937 cells were studied at two pH levels with FACScan flow cytometry. The cells were exposed in vitro up to 60 min in a buffered incubation medium to either pH 5.10 or pH 7.34. An inverse correlation was found between beta 2M and bicarbonate concentrations in plasma in the stable chronic renal failure patients (r = -0.54; P < 0.05) and in the uremic patients before their first dialysis (r = -0.72; P < 0.05). In hemodialysis patients, blood pH and plasma bicarbonate values were lower (P < 0.05) and beta 2M concentrations in plasma were higher (P < 0.05) with acetate than with bicarbonate dialysate. In normal men, NH4Cl resulted in an increase (P < 0.05) in beta 2M mRNA expression in lymphocytes by an average factor of 1.5 (range, 1.1 to 1.8). In U 937 cells, the cell surface expression of beta 2M and HLA Class I heavy chain assembled with beta 2M decreased at low pH compared with normal pH. Concomitantly, an increase in beta 2M release into the supernatant was observed, possibly as the result of beta 2M dissociation from cell surface HLA Class I complex. The results suggest that metabolic acidosis may enhance cellular beta 2M generation and release.
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Molina Nuñez, Manuel, Rosa de Alarcón, Susana Roca, Gracia Álvarez, María Soledad Ros, Cristina Jimeno, Laura Bucalo, Isabel Villegas, and María Ángeles García. "Citrate versus Acetate-Based Dialysate in On-Line Haemodiafiltration. A Prospective Cross-Over Study." Blood Purification 39, no. 1-3 (2015): 181–87. http://dx.doi.org/10.1159/000371569.
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Background and Aims: A bicarbonate dialysate acidified with citrate (CD) has been reported to have local anticoagulant effect and improves biocompatibility. This study examines the effect of CD on dialysis efficiency, coagulation, acid-base status, electrolytes, and inflammation in patients in on-line hemodiafiltration (OL-HDF). Methods: 35 patients in OL-HDF were enrolled in a prospective, cross-over study for a 24-week period and two phases alternating CD and acetate dialysate fluid (AD). Parameters on study were predialysis levels of bicarbonate and ionic calcium, reactive C Protein (CRP), and beta-2 microglobulin (B2MG) and postdialysis levels of activated tromboplastine time, bicarbonate, and ionized calcium. Results: No significant differences in coagulation parameters, pH, and predialysis bicarbonate were found. The postdialysis bicarbonate and postdialysis calcium were lower with CD. Dialysis efficiency was greater with CD. Regarding inflammatory parameters, both CRP and B2MG were lower using CD. Conclusion: The use of CD is safe and effective in OL-HDF, and it improves dialysis efficacy, postdialysis alkalosis, and inflammation.
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YOSHIDA, Masaki. "Effect of pH and Osmolality in Dialysate Fluids on Active Oxygen Generation by Polymorphonuclear Leukocytes." Journal of the Japanese Association for Infectious Diseases 67, no. 5 (1993): 444–51. http://dx.doi.org/10.11150/kansenshogakuzasshi1970.67.444.
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Tejedor, A., D. Conesa, N. Hernando, L. Hernando, and J. M. Lopez-Novoa. "Absence of an endogenous regulator of Na+,K+-ATPase activity in the tissues of cirrhotic rats." Biochemistry and Cell Biology 66, no. 3 (March 1, 1988): 218–30. http://dx.doi.org/10.1139/o88-029.
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Microsomal Na+,K+-ATPase isolated from the renal cortex of rats with CCl4-induced cirrhosis (CIR) showed a higher specific activity than the enzyme obtained from control rats (COR). Kinetic studies showed a lower K0.5 for ATP (0.08 ± 0.03 vs. 0.24 ± 0.04 mM; p < 0.05), a lower Na+ activation constant (9.6 ± 1.5 vs. 19.0 ± 1.7 mM; p < 0.05), and a higher K+ activation constant (1.2 ± 0.1 vs. 0.6 ± 0.1 mM; p < 0.05) for CIR. The optimal pH of the enzyme was 0.5 units higher in CIR than COR. The fluorescence of eosin-treated enzymes indicated a higher ratio of E1/E2 forms of Na+,K+-ATPase in CIR. The K+-activated p-nitrophenylphosphatase (pNPPase) activity of the enzyme was lower in CIR than COR rats (1.5 ± 0.1 vs. 2.2 ± 0.1 mU/mg; p < 0.05). Dialysing (24 h) COR microsomes reproduced most of the changes observed in CIR enzymes (kinetics, optimal pH, and eosin fluorescence). Lyophilized dialysate of COR, but not of CIR microsomes, inhibits Na+,K+-ATPase activity. These results suggest that a dialysable inhibitor modifies the Na+,K+-ATPase activity in the kidney of COR which is almost absent in that of CIR. The absence of this factor may lead to the overall inability to excrete Na+ in the cirrhotic state.
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Ayuzawa, Nobuhiro, Yoshitaka Ishibashi, Yutaka Takazawa, Haruki Kume, and Toshiro Fujita. "Peritoneal Morphology after Long-Term Peritoneal Dialysis with Biocompatible Fluid: Recent Clinical Practice in Japan." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 32, no. 2 (March 2012): 159–67. http://dx.doi.org/10.3747/pdi.2010.00234.
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♦BackgroundMorphology changes of the peritoneal membrane after long-term peritoneal dialysis (PD) consist of denudation of peritoneal mesothelial cells, interstitial sclerosis, and hyalinizing vasculopathy. Those changes are considered to be the result of uremia and bioincompatible effects of conventional acidic lactate-buffered dialysate with glucose degradation products (GDPs). In the last decade, biocompatible dialysate with neutral pH and low GDPs has become widely used. Clinical practice has been modified in Japan, especially for anuric patients, and now includes the use of hybrid therapy. The impact on peritoneal morphology has not been well reported.♦ ObjectiveThe aim of the present study was to investigate the long-term effect on peritoneal morphology and function of biocompatible fluid use and current clinical practice in Japan, including hybrid dialysis therapy.♦MethodsWe evaluated peritoneal biopsy specimens from patients who had undergone PD for more than 3 years. We used the average peritoneal thickness (APT) of the submesothelial compact zone as a marker of interstitial sclerosis and the lumen/vessel diameter ratio (L/V ratio) at postcapillary venules as a marker of hyalinizing vasculopathy. Demography and other data for the patients, including dialysate-to-plasma (D/P) ratio of creatinine, were obtained at baseline and every 6 months by peritoneal equilibration test.♦ResultsBetween 2002 and 2009, 110 patients started PD therapy with biocompatible dialysate at Tokyo University Hospital. Among them, 11 patients (8 men, 3 women; age: 54.2 ± 11.8 years; 1 with diabetes mellitus) were enrolled into this morphology study. The mean duration of PD in this group was 61 ± 11.3 months, and the mean time to peritoneal biopsy was 58 ± 15.1 months. The median APT was 180 μm (96 – 1424 μm), and the median L/V ratio was 0.66 (0.46 – 0.74). No obvious correlations between APT, L/V ratio, and PD duration were detected. The D/P creatinine of the 11 patients was maintained at a favorably low value, comparable with that of the other 99 patients.♦ConclusionsPeritoneal dialysis therapy using biocompatible dialysate in conjunction with modification of clinical practice may minimize the progression of peritoneal interstitial sclerosis and hyalinizing vasculopathy, preserving favorable peritoneal function for more than 3 years.
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Garcia, Hector, Julio Hernández-Jaras, María del Carmen Cruz, Isabel Agramunt, Consuelo Calvo, and Vicente Cerrillo. "Short- and Medium-Term Increase of CA125 in Peritoneal Effluent using a Neutral-pH Solution." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 23, no. 4 (July 2003): 375–80. http://dx.doi.org/10.1177/089686080302300411.
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♦ Objective To investigate the effects of an alternative peritoneal dialysis (PD) solution composed of a lactate/bicarbonate (Lac/Bic) mixture (35/2 mmol/L), pH 7.0, on the appearance of cancer antigen 125 (CA125) in the peritoneal effluent. ♦ Methods Eight stable PD patients received a conventional solution containing 35 mmol/L lactate (Lac) for 11.9 ± 9.2 months, and then changed to Lac/Bic for 3.1 ± 0.7 months. Each patient acted as his/her own control. ♦ Results We studied 4 males and 4 females with a mean age of 57.4 ± 16.8 years. Higher concentrations (U/mL) ( p < 0.005) and appearance rates (AR) (U/min) ( p < 0.05) of CA125 in the dialysate were observed with Lac/Bic than with Lac, during the sampling times of the peritoneal equilibration test (10, 120, and 240 minutes) and in the overnight effluent: CA125 5.7 versus 0.6, 18.9 versus 1.9, 29.7 versus 3.7, and 43.2 versus 5.5 U/mL; and AR 1177 versus 125, 354 versus 36,297 versus 37, and 194 versus 26 U/min, respectively. Mean CA125 content in the 24-hour dialysate was 34.2 U/min (baseline) and 30.9 U/min (11.9 months) with Lac, and 207.9 U/min and 185 U/min after 1.6 and 3.1 months with Lac/Bic ( p = 0.009). The intraperitoneal pH was more physiological during the dwell with the Lac/Bic solution. ♦ Conclusions The CA125 levels in the peritoneal effluent with Lac/Bic are an effect of the solution's neutral pH, as other factors of the prescription were constant. The Lac/Bic solution is more biocompatible than Lac, reflecting short- and medium-term changes in the mesothelial cells, whose clinical significance has not yet been determined.
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CHANTAYSAKORN, PANITA, and R. L. RICHTER. "Antimicrobial Properties of Pepsin-Digested Lactoferrin Added to Carrot Juice and Filtrates of Carrot Juice." Journal of Food Protection 63, no. 3 (March 1, 2000): 376–80. http://dx.doi.org/10.4315/0362-028x-63.3.376.
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The objective of this study was to determine the antimicrobial activity of pepsin-digested lactoferrin added to carrot juice and filtrates prepared from carrot juice. Lactoferrin isolated from raw skim milk was digested by pepsin for 4 h at pH 3. The digest of lactoferrin was lyophilized, and the antimicrobial activity of the digests was determined in peptone-yeast-glucose broth, carrot juice, permeate from carrot juice, and the dialysate of carrot juice permeate using Esherichia coli (American Type Culture Collection strain 35343) as the test organism. Growth of E. coli and the inhibitory effect of the peptide were greater in peptone-yeast-glucose broth at pH 7 than at pH 4. The peptic digest of lactoferrin did not have antimicrobial properties in carrot juice at concentrations of less than 10 mg/ml of juice. Carrot juice was filtered through a membrane with a molecular weight rejection of 10,000 or 500 Da, and the permeate was dialyzed against distilled water. Growth of E. coli was delayed in the filtrate by 5 mg but not by 1 mg of the peptic digest of lactoferrin per ml of filtrate. Bacterial counts of the control and experimental samples were not significantly different after 24 h of incubation. The peptic digest of lactoferrin at a concentration of 5 mg of digest per ml of dialysate was bacteriostatic toward E. coli after 24 h of incubation at 23°C. Dialysis of permeate caused a percentage reduction in cation concentration in the permeate ranging from 69.23% (Co) to 99.32% (Na). The antimicrobial activity of lactoferrin added to carrot juice was probably inhibited by cations.
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Calzavara, P., G. Calconi, G. Da Rin, E. Canini, and F. Paolini. "A New Biosensor for Continuous Monitoring of the Spent Dialysate Urea Level in Standard Hemodialysis." International Journal of Artificial Organs 21, no. 3 (March 1998): 147–50. http://dx.doi.org/10.1177/039139889802100305.
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This study gives the results in terms of precision and repeatability of a new on-line urea monitoring system (Ureascan P2 Hospal) capable of measuring the urea concentrations in the spent dialysate. The Ureascan P2 Hospal (UP2H), fitted on single-pass dialysis machines (Integra-Hospal), functions by the presence of a disposable mini-reactor containing urease. The passage through the reactor of a minimum quantity of spent dialysate from the filter diluted with a pH 7 buffer solution (1 ml/min) increases its ionic strength, which is detected by a differential measurement of conductivity in proportion to the urea concentration in the dialysis liquid. We studied 13 dialysis sessions, with bicarbonate buffer, in 8 anuric patients. From 4 to 7 dialysate samples were taken during each treatment to determine the urea and 65 samples were analysed overall. Urea values from the UP2H were compared with those measured on the Dimension Du Pont analyser. Simple linear regression analysis showed an excellent correlation between the 2 measuring methods (r=0.987; p<0.001). The Bland-Altman test gave an average difference between the urea values measured with the UP2H and in the laboratory of 1.3±1.2 mg/dl. The agreement limits between 2 SD were - 1.2 mg/dl and +3.8 mg/dl respectively. In conclusion, the UP2H we have developed has proved to be a reliable and very useful instrument for adapting, through the urea kinetic mathematical models, the dialysis dose for individual patients.
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Hamada, Chieko, Kayo Hayashi, Ichiyu Shou, Masanori Inaba, Yuuki Ro, Hiroaki Io, Kunimi Maeda, Mitsumine Fukui, and Yasuhiko Tomino. "Pharmacokinetics of Calcitriol and Maxacalcitol Administered into Peritoneal Dialysate Bags in Peritoneal Dialysis Patients." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 25, no. 6 (November 2005): 570–75. http://dx.doi.org/10.1177/089686080502500613.
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Objectives It is well known that injection of calcitriol (CT) or maxacalcitol (OCT) is very effective in hemodialysis patients with secondary hyperparathyroidism (2HPT). However, it is difficult to use these drugs with peritoneal dialysis (PD) patients with 2HPT because these drugs must be injected two or three times per week. The objective of the present study was to evaluate the stability of physiological activities of CT and OCT in PD bags and to determine the CT or OCT dosage for intraperitoneal (IP) administration. Materials and Methods We added CT 1.5 μg or OCT 10 μg to Dianeal PD-2 (approximate pH = 5.0, calcium = 0.87 mmol/L; Baxter, Tokyo, Japan), Midpeliq 250 (approximate pH = 7.0, Ca = 1.0 mmol/L; Terumo Corporation, Tokyo, Japan), and Peritoliq 250 (approximate pH = 5.5, Ca = 1.0 mmol/L; Terumo Corp.). Dialysis solutions were collected from the PD bags at 0, 1, 4, 8, 12, 24, 48, and 72 hours after addition of CT and OCT. The activities of CT and OCT in the dialysis effluent were measured by radioimmunoassay. The levels of serum and effluent OCT after a single IP administration of 10 μg OCT were examined in 4 PD patients with advanced 2HPT. Results Although the levels of CT and OCT in PD bags made of polyvinyl resins decreased by 70% – 75% immediately after injection, levels in PD bags made of polypropylene resins decreased only slightly. The concentration of CT mixed into the acidic solution in glass containers was stable; the decreased concentration of CT in the PD solution might be due to adsorption onto polyvinyl resins. The maximum serum concentration after IP administration of 10 μg OCT was 750 pg/mL after 5 minutes, and remained at 500 pg/mL at 60 minutes. These results show good peritoneal transport of OCT but not rapid disappearance, unlike intravenous administration. Conclusions If peritoneal administration of vitamin D derivatives is contemplated, it is important to select the composition of PD bag resins, type of vitamin D analog, and time lag to use when deciding the dosage of injectable vitamin D preparations, such as OCT or CT, for IP administration to PD patients. It appears that IP administration in overnight dwells might be useful for PD patients as a complementary vitamin D preparation.
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MacLean, Dave A., Kathryn F. LaNoue, Kristen S. Gray, and Lawrence I. Sinoway. "Effects of hindlimb contraction on pressor and muscle interstitial metabolite responses in the cat." Journal of Applied Physiology 85, no. 4 (October 1, 1998): 1583–92. http://dx.doi.org/10.1152/jappl.1998.85.4.1583.
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We used the microdialysis technique to measure the interstitial concentration of several putative metabolic stimulants of the exercise pressor reflex during 3- and 5-Hz twitch contractions in the decerebrate cat. The peak increases in heart rate and mean arterial pressure during contraction were 20 ± 5 beats/min and 21 ± 8 mmHg and 27 ± 9 beats/min and 37 ± 12 mmHg for the 3- and 5-Hz stimulation protocols, respectively. All variables returned to baseline after 10 min of recovery. Interstitial lactate rose ( P < 0.05) by 0.41 ± 0.15 and 0.56 ± 0.16 mM for the 3- and 5-Hz stimulation protocols, respectively, and were not statistically different from one another. Interstitial lactate levels remained above ( P < 0.05) baseline during recovery in the 5-Hz group. Dialysate phosphate concentrations (corrected for shifts in probe recovery) rose with stimulation ( P < 0.05) by 0.19 ± 0.08 and 0.11 ± 0.03 mM for the 3- and 5-Hz protocols. There were no differences between groups. The resting dialysate K+ concentrations for the 3- and 5-Hz conditions were 4.0 ± 0.1 and 3.9 ± 0.1 meq/l, respectively. During stimulation the dialysate K+ concentrations rose steadily for both conditions, and the increase from rest to stimulation ( P < 0.05) was 0.57 ± 0.19 and 0.81 ± 0.06 meq/l for the 3- and 5-Hz conditions, respectively, with no differences between groups. Resting dialysate pH was 6.915 ± 0.055 and 6.981 ± 0.032 and rose to 7.013 ( P < 0.05) and 7.053 ( P < 0.05) for the 3- and 5-Hz conditions, respectively, and then became acidotic (6.905, P < 0.05) during recovery (5 Hz only). This study represents the first time simultaneous measurements of multiple skeletal muscle interstitial metabolites and pressor responses to twitch contractions have been made in the cat. These data suggest that interstitial K+ and phosphate, but not lactate and H+, may contribute to the stimulation of thin fiber muscle afferents during contraction.
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Zhou, Hui, Ashley Ribera, Amonae Dabbs-Brown, Uliana Danilenko, and Hubert W. Vesper. "Measurement of Free Testosterone in Serum Using Equilibrium DialysisCoupled With ID-UHPLC-MS/MS: Comparison Between Equilibrium Devices." Journal of the Endocrine Society 5, Supplement_1 (May 1, 2021): A760. http://dx.doi.org/10.1210/jendso/bvab048.1545.
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Abstract Free testosterone (FT) has been used as a biomarker in clinical patient care and public health research to assess and manage patients with androgenic abnormalities. The latest Endocrine Society clinical practice guideline for testosterone therapy in men with hypogonadism recommends measuring FT for those with borderline and low total testosterone concentrations, or those who have conditions that change SHBG concentrations, such as some metabolic or hormonal diseases, certain medication use, or SHBG genetic polymorphisms. Measuring FT is technically challenging and shows high variability. The CDC clinical standardization program is developing a high throughput method using the gold-standard equilibrium dialysis (ED) procedure with isotope dilution ultra-high-performance liquid chromatography tandem mass spectrometry (ID-UHPLC-MS/MS). A serum sample was dialyzed against a protein-free HEPES buffer (pH 7.4) at 37 °C until equilibrium. After isolating endogenous FT from protein-bound testosterone by ED, isotope-labeled internal standard (13C3-testosterone) was added to the dialysate for quantification. Certified pure primary reference material (National Measurement Institute M914) was used to prepare calibrators, enabling traceable quantitation and ensuring measurement trueness. FT was further isolated from the dialysate matrix using supported liquid extraction and a chromatographic separation from interfering compounds and quantitation by tandem MS. The dialysis step requires maintaining the endogenous free hormone equilibrium so that results in dialysate reflect FT concentrations in the blood without influence from dilution, temperature, or pH. The dialyzer system has a 1:1 sample-to-buffer volume and has been used in reference measurement procedures for free hormone measurements, serving as the standard for method performance comparison. Four commercially available devices designed for high throughput in a multiple well-plate format, requiring respective sample-to-buffer ratios, were evaluated for their recovery, speed, ease of automation by a liquid handling system, repeatability, and robustness. Preliminary results showed that a device with 1:1 sample-to-buffer volume had the most comparable results to those obtained from the standard dialyzer, with the mean bias less than 15%. The device with the highest sample-to-buffer ratio showed bias as high as 50%. These data suggest that controlling sample-to-buffer ratio is a critical step in ED FT method.
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Htay, Htay, Yeoungjee Cho, Elaine M. Pascoe, Darsy Darssan, Carmel Hawley, and David W. Johnson. "Predictors of Residual Renal Function Decline in Peritoneal Dialysis Patients: ThebalANZ Trial." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 37, no. 3 (May 2017): 283–89. http://dx.doi.org/10.3747/pdi.2016.00206.
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ObjectivePreservation of residual renal function (RRF) is associated with improved survival. The aim of the present study was to identify independent predictors of RRF and urine volume (UV) in incident peritoneal dialysis (PD) patients.MethodsThe study included incident PD patients who were balANZ trial participants. The primary and secondary outcomes were RRF and UV, respectively. Both outcomes were analyzed using mixed effects linear regression with demographic data in the first model and PD-related parameters included in a second model.ResultsThe study included 161 patients (mean age 57.9 ± 14.1 years, 44% female, 33% diabetic, mean follow-up 19.5 ± 6.6 months). Residual renal function declined from 7.5 ± 2.9 mL/min/1.73 m2at baseline to 3.3 ± 2.8 mL/min/1.73 m2at 24 months. Better preservation of RRF was independently predicted by male gender, higher baseline RRF, higher time-varying systolic blood pressure (SBP), biocompatible (neutral pH, low glucose degradation product) PD solution, lower peritoneal ultrafiltration (UF) and lower dialysate glucose exposure. In particular, biocompatible solution resulted in 27% better RRF preservation. Each 1 L/day increase in UF was associated with 8% worse RRF preservation ( p = 0.007) and each 10 g/day increase in dialysate glucose exposure was associated with 4% worse RRF preservation ( p < 0.001). Residual renal function was not independently predicted by body mass index, diabetes mellitus, renin angiotensin system inhibitors, peritoneal solute transport rate, or PD modality. Similar results were observed for UV.ConclusionsCommon modifiable risk factors which were consistently associated with preserved RRF and residual UV were use of biocompatible PD solutions and achievement of higher SBP, lower peritoneal UF, and lower dialysate glucose exposure over time.
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Wadhwa, Nand K., M. Seliger, Harly E. Greenberg, Edward Bergofsky, and Wallace B. Mendelson. "Sleep Related Respiratory Disorders in End-Stage Renal Disease Patients on Peritoneal Dialysis." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 12, no. 1 (January 1992): 51–56. http://dx.doi.org/10.1177/089686089201200112.
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Study Objective To assess the possible effects of peritoneal dialysis (PD) on sleep-related respiration, which might result from dialysate bulk load in the abdomen and/or alterations in metabolic control of respiration during sleep. Design Subjective and objective measures of sleep were prospectively compared on randomly assigned nights with PD fluid (2.0 L) and without PD fluid in the peritoneal cavity in 11 end-stage renal disease (ESRD) patients on PD. Setting Tertiary-referral university hospital. Patients and Methods Fifteen consecutive patients on peritoneal dialysis who complained of chronic sleep disturbance and requested sedative were selected. Four patients declined polysomnographic studies. Consequently, 11 ESRD patients (8 males and 3 females) with a mean age of 63±4 (SEM) years were studied. Results Eight of the 11 patients reported multiple types of sleep difficulties. Polysomnographic recordings revealed significant primarily obstructive sleep apnea in 6 of 11 patients on at least 1 of 2 nights. Arterial blood pH, paO2, and paC02 did not differ between nights with and without PD fluid in the peritoneal cavity in the group as a whole. In the 6 patients with sleep apnea, Pa02 was significantly lower (p<0.05) during the night with (Pa02=78±7 mmHg) than during the night without PD fluid (Pa02=92±4 mmHg). In the apneic patients, the amount of dialysate drained in the morning was negatively correlated with the minimum arterial oxygen saturation during the night (r=-0.94; p<0.005). Conclusions This study indicates a significant relationship between PD patients with chronic sleep disturbance and sleep apnea syndrome. These data suggest that apneic patients may be susceptible to complications of dialysate bulk effect on oxygen desaturation.
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Park, Sun-Hee, Eun-Gyui Lee, In-San Kim, Yong-Jin Kim, Dong-Kyu Cho, and Yong-Lim Kim. "Effect of Glucose Degradation Products on the Peritoneal Membrane in a Chronic Inflammatory Infusion Model of Peritoneal Dialysis in the Rat." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 24, no. 2 (March 2004): 115–22. http://dx.doi.org/10.1177/089686080402400202.
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Background Long-term use of the peritoneal membrane as a dialyzing membrane is hampered by its eventual deterioration. One of the contributing factors is glucose degradation products (GDPs) in the dialysis solution. In this study, we evaluated the effect of a low GDP solution on peritoneal permeability, the structural stability of the peritoneal membrane, and vascular endothelial growth factor (VEGF) production in a chronic inflammatory infusion model of peritoneal dialysis (PD) in the rat. Methods Male Sprague–Dawley rats were divided into 3 groups: a conventional solution group (group C, n = 12), a test solution group (group T, n = 12), and a normal control group (group NC, n = 8). Group T rats were infused with low GDP solution (2.3% glucose solution with two compartments), and group C rats with conventional dialysis solution (2.3% glucose solution), adjusted to pH 7.0 before each exchange. Animals were infused through a permanent catheter with 25 mL of dialysis solution. In both groups, peritoneal inflammation was induced by infusing dialysis solution supplemented with lipopolysaccharide on days 8, 9, and 10 after starting dialysate infusion. Peritoneal membrane function was assessed before and 6 weeks after initiating dialysis using the 1-hour peritoneal equilibration test (PET) employing 4.25% glucose solution. Both VEGF and transforming growth factor β1 (TGFβ1) in the dialysate effluent were measured by ELISA. The number of vessels in the omentum was counted after staining with anti-von Willebrand factor, and the thickness of submesothelial matrix of the trichrome-stained parietal peritoneum was measured. Peritoneal tissue was analyzed for VEGF protein using immunohistochemistry. Results At the end of 6 weeks, the rate of glucose transport (D/D0, where D is glucose concentration in the dialysate and D0 is glucose concentration in the dialysis solution before it is infused into the peritoneal cavity) was higher in group T ( p < 0.05) than in group C. Dialysate-to-plasma ratio (D/P) of protein was lower in group T ( p < 0.05) than in group C; D/Purea, D/Psodium, and drain volumes did not differ significantly between groups C and T. Dialysate VEGF and TGFβ levels were lower in group T ( p < 0.05) than in group C. Immunohistochemical studies also revealed less VEGF in the peritoneal membranes of group T. There were significantly more peritoneal blood vessels in group C ( p < 0.05) than in group T, but the thickness of submesothelial matrix of the parietal peritoneum was not different between the two groups. The VEGF levels in the dialysate effluent correlated positively with the number of blood vessels per field ( r = 0.622, p < 0.005). Conclusion Using a chronic inflammatory infusion model of PD in the rat, we show that dialysis with GDP-containing PD fluid is associated with increased VEGF production and peritoneal vascularization. Use of low GDP solutions may therefore be beneficial in maintaining the function and structure of the peritoneal membrane during long-term PD.
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Jones, G. V., B. M. Wall, H. H. Williams, D. N. Presley, D. G. Sapir, and C. R. Cooke. "Modulation of plasma aldosterone by physiological changes in hydrogen ion concentration." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 262, no. 2 (February 1, 1992): R269—R275. http://dx.doi.org/10.1152/ajpregu.1992.262.2.r269.
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To assess the effect of extracellular hydrogen ion concentration (PH+) on aldosterone secretion, studies in which other known modulators could be controlled were performed on 13 patients undergoing hemodialysis. High (35 mM) or low (14-17 mM) dialysate bicarbonate concentrations were utilized on separate days to either decrease or increase PH+, while plasma potassium concentrations (PK) were held at constant levels and changes in plasma renin activity (PRA) were minimized by avoiding changes in body weight. Changes in PH+ were associated with concordant changes in plasma aldosterone concentration (Pa) in both high- and low-bicarbonate studies. When these changes in Pa in high- and low-bicarbonate studies were analyzed together as a function of corresponding changes in PH+, a significant correlation could be demonstrated (r = 0.659, P less than 0.001). There was no correlation between changes in Pa and changes in PK, plasma sodium, plasma adrenocorticotropic hormone (ACTH), or PRA. Using the same methods to control PH+ and other variables during hemodialysis, the effects of altered PH+ on ACTH-stimulated aldosterone and cortisol secretion were evaluated in studies on six patients who received incremental infusions of ACTH after pretreatment with dexamethasone. In these studies, there was no demonstrable effect of PH+ on Pa or plasma cortisol concentration. We conclude that physiological changes in PH+ have a weak modulating effect on basal aldosterone secretion that may not be evident in the presence of other acutely applied stimuli.
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Hart, Kevin, Martyn Harvey, Mingtan Tang, Zimei Wu, and Grant Cave. "Liposomes to Augment Dialysis in Preclinical Models: A Structured Review." Pharmaceutics 13, no. 3 (March 16, 2021): 395. http://dx.doi.org/10.3390/pharmaceutics13030395.
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In recent years, a number of groups have been investigating the use of “empty” liposomes with no drug loaded as scavengers both for exogenous intoxicants and endogenous toxic molecules. Preclinical trials have demonstrated that repurposing liposomes to sequester such compounds may prove clinically useful. The use of such “empty” liposomes in the dialysate during dialysis avoids recognition by complement surveillance, allowing high doses of liposomes to be used. The “reach” of dialysis may also be increased to molecules that are not traditionally dialysable. We aim to review the current literature in this area with the aims of increasing awareness and informing further research. A structured literature search identified thirteen papers which met the inclusion criteria. Augmenting the extraction of ammonia in hepatic failure with pH-gradient liposomes with acidic centres in peritoneal dialysis is the most studied area, with work progressing toward phase one trials. Liposomes used to augment the removal of exogenous intoxicants and protein-bound uraemic and hepatic toxins that accumulate in these organ failures and liposome-supported enzymatic dialysis have also been studied. It is conceivable that liposomes will be repurposed from the role of pharmaceutical vectors to gain further indications as clinically useful nanomedical antidotes/treatments within the next decade.
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Ramirez, G., G. L. Collice, S. James, C. C. Johns, and W. P. Nelson. "Increase in P50 with the use of Bicarbonate Hemodialysis." International Journal of Artificial Organs 10, no. 6 (November 1987): 361–66. http://dx.doi.org/10.1177/039139888701000607.
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We studied the effect of bicarbonate and acetate on oxygenation during dialysis in ten male chronic dialysis patients. The dialysis delivery system and dialysate constituents were identical except for the use of either bicarbonate or acetate. We found no hemodynamic differences between the two kinds of dialysis. Blood PO2 fell by a similar amount, but blood PCO2 was higher during bicarbonate dialysis. The blood pH became alkalotic by the second hour of bicarbonate dialysis and remained so throughout the dialysis, whereas blood pH became alkalotic only at the end of acetate dialysis. The P50 increased significantly only during bicarbonate dialysis, but 2.3 DPG concentration did not change. Red cell volume, assessed by the mean corpuscular hemoglobin concentration, was unchanged. Without changes in the red cell volume we cannot explain the observed changes in P50 in the absence of concomitant changes in 2.3 DPG concentration.
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Cai, Michael M. X., Edward R. Smith, Annette Kent, Louis Huang, Timothy D. Hewitson, Lawrence P. McMahon, and Stephen G. Holt. "Calciprotein Particle Formation in Peritoneal Dialysis Effluent is Dependent on Dialysate Calcium Concentration." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 38, no. 4 (July 2018): 286–92. http://dx.doi.org/10.3747/pdi.2017.00163.
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Background The accumulation of fetuin-A-containing calciprotein particles (CPP) in the serum of patients with renal disease and those with chronic inflammation may be involved in driving sterile inflammation and extraosseous mineral deposition. We previously showed that both fetuin-A and CPP were present in the peritoneal dialysis (PD) effluent of stable PD patients. It is unknown whether different PD fluids might affect the formation of CPP in vivo. Method Peritoneal effluent from 12 patients was collected after a 6-hour dwell with 7 different commercial PD fluids. Calciprotein particles and inflammatory cytokines were measured by flow cytometry. Results High inter-subject variability in CPP concentration was observed. Peritoneal dialysis fluids containing 1.75 mmol/L calcium were associated with enhanced formation of CPP in vivo, compared with fluids containing 1.25 mmol/L calcium. Osmotic agent, fluid pH, and glucose concentration did not affect CPP formation. Peritoneal dialysis effluent CPP levels were not associated with changes in inflammatory cytokines. Conclusion High calcium-containing PD fluids favor intraperitoneal CPP formation. This finding may have relevance for future PD fluid design.
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Gao, Zhaohui, Jialiu D. Li, Lawrence I. Sinoway, and Jianhua Li. "Effect of muscle interstitial pH on P2X and TRPV1 receptor-mediated pressor response." Journal of Applied Physiology 102, no. 6 (June 2007): 2288–93. http://dx.doi.org/10.1152/japplphysiol.00161.2007.
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Activation of purinergic P2X receptors and transient receptor potential vanilloid type 1 (TRPV1) on muscle afferent nerve evokes the pressor response. Because P2X and TRPV1 receptors are sensitive to changes in pH, the aim of this study was to examine the effects of muscle acidification on those receptor-mediated cardiovascular responses. In decerebrate rats, the pH in the hindlimb muscle was adjusted by infusing acidic Ringer solutions into the femoral artery. Dialysate was then collected using microdialysis probes inserted into the muscles, and pH was measured. The interstitial pH was 7.53 ± 0.01, 7.22 ± 0.02, 6.94 ± 0.04, and 6.59 ± 0.03 in response to arterial infusion of the Ringer solution at pH 7.4, 6.5, 5.5, and 4.5, respectively. Femoral arterial injection of α,β-methylene-ATP (P2X receptor agonist) in the concentration of 0.25 mM (volume, 0.15–0.25 ml; injection duration, 1 min) at the infused pH of 7.4, 6.5, and 5.5 increased mean arterial pressure (MAP) by 29 ± 2, 24 ± 3, and 21 ± 3 mmHg, respectively ( P < 0.05, pH 5.5 vs. pH 7.4). When pH levels in the infused solution were 7.4, 6.5, 5.5, and 4.5, capsaicin (1 μg/kg), a TRPV1 agonist, was injected into the artery. This elevated MAP by 29 ± 4, 33 ± 2, 35 ± 3, and 40 ± 3 mmHg, respectively ( P < 0.05, pH 4.5 vs. pH 7.4). Furthermore, blocking acid-sensing ion channel (ASIC) blunted pH effects on TRPV1 response. Our data indicate that 1) muscle acidosis attenuates P2X-mediated pressor response but enhances TRPV1 response; 2) exaggerated TRPV1 response may require lower pH in muscle, and the effect is likely to be mediated via ASIC mechanisms. This study provides evidence that muscle pH may be important in modulating P2X and TRPV1 responsiveness in exercising muscle.
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B, Sandhya, and Nagamani T.S. "Isolation, Purification and Analysis of Pancreatic Lipase from ‘Gallus gallus domesticus’." International Journal of Innovative Science and Research Technology 5, no. 7 (July 29, 2020): 590–94. http://dx.doi.org/10.38124/ijisrt20jul338.
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This article discusses the isolation of pancreatic lipase enzyme from the pancreas of Gallus gallus domesticus. Whereas lipase catalyses the hydrolysis and the synthesis of esters formed from glycerol and long-chain fatty acids. Lipases occur widely in nature, it involves applications like organic syntheses, hydrolysis of fats, oils, modification of fats, flavor enhancement in food processing, detergent industries, pharmaceutical industries, chemical analyses, and biodiesel production. Pancreatic lipase was purified to the homogeneity by 70% saturated Ammonium sulphate further, it was dialysate using the dialysis membrane and then gel filtration chromatography was carried out by Sephadex G-75 and DEAE cellulose. The molecular weight of purified lipase sample was determined by SDSPAGE, it was found to be 98KDa. The lipase was active in the pH range of 5-10 with an optimum pH of 6.0. The optimum temperature for the hydrolysis of olive oil was 37ºC in the range of 25ºC - 50ºC.
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Breborowicz, A., H. Rodela, L. Martis, and D. G. Oreopoulos. "Intracellular Glutathione in Human Peritoneal Mesothelial Cells Exposed in vitro to Dialysis Fluid." International Journal of Artificial Organs 19, no. 5 (May 1996): 268–75. http://dx.doi.org/10.1177/039139889601900503.
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Effect of peritoneal dialysis fluids on glutathione (GSH/GSSG) level in human peritoneal mesothelial cells was tested in in vitro experiments. To mimic in vivo conditions, cells were initially exposed to dialysis fluids (Dianeal 1.36%, Dianeal 2.27%, Dianeal 3.86%) that subsequently were diluted with dialysate effluent at time intervals. GSH/GSSG concentration in cells initially decreased but returned to normal values thereafter. This decrease in the intracellular concentration of glutathione was less when pH of the tested dialysis fluid was adjusted to 7.3. In further experiments with mesothelial cells exposed to Earle's salts solution supplemented with glucose and/or lactate, we have shown that in the presence of low pH, lactate is the main factor causing depletion of intracellular glutathione. When added to the dialysis solution at a concentration of 0.1 mM, L-2-oxothiazolidine-4-carboxylate, a precursor of glutathione, not only prevents the initial decrease in glutathione concentration but also augments the final intracellular level of this thiol.
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Ing, T. S., M. L. Yang, V. L. Yang, F. K. M. Wong, Y. L. Cheng, S. R. Guddeti, and A. W. Yu at. "Effect of an Acidic Pyruvate-based Peritoneal Dialysis Solution on the pH of a Residual Peritoneal Dialysate Fluid." Artificial Organs 20, no. 3 (March 1996): 264–66. http://dx.doi.org/10.1111/j.1525-1594.1996.tb04436.x.
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Topley, Nicholas, Tomasz Liberek, Chandra Mistry, Gerald A. Coles, and John D. Williams. "Cell Function, Viability, and Icodextrin." Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis 14, no. 2_suppl (February 1994): 28–32. http://dx.doi.org/10.1177/089686089401402s04.
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The bioincompatibility of conventional dialysis fluids is related primarily to the combination of low pH and high lactate concentrations. This results in the reduction of intracellular pH and a consequent inhibition of cell function. The use of high glucose concentrations to increase fluid osmolality adds to the cytotoxicity and has a further inhibitory effect on peritoneal cells. The clinical need for fluids that provide sustained ultrafiltration has led to a novel approach using a high molecular weight glucose polymer (icodextrin) to generate an ultrafiltration gradient in an iso-osmolar fluid. In the studies presented we have had the opportunity of examining, in the laboratory setting, the biocompatibility of such a fluid. As in previous studies with conventional fluids, pH per se has a profound effect on most modalities of cell function. In addition, there appearto be a few areas where problems can be ascribed to icodextrin itself. Furthermore, it is possible that Staph. epidermidis survives better in icodextrin than in conventional dialysate. Whether the benefits of sustained ultrafiltration outweigh the possible disadvantages outlined can only be judged when the results from ongoing clinical trials are available.
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Lamoreaux, William J., David L. Smalley, Larry M. Baddour, and Alfred P. Kraus. "Scanning Electron Microscopy of Staphylococcus Epidermidis Adherence to Continuous Ambulatory Peritoneal Dialysis Catheters." Proceedings, annual meeting, Electron Microscopy Society of America 43 (August 1985): 520–21. http://dx.doi.org/10.1017/s0424820100119429.
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Infections associated with the use of intravascular devices have been documented and have been reported to be related to duration of catheter usage. Recently, Eaton et al. reported that Staphylococcus epidermidis may attach to silastic catheters used in continuous ambulatory peritoneal dialysis (CAPD) treatment. The following study presents findings using scanning electron microscopy (SEM) of S. epidermidis adherence to silastic catheters in an in vitro model. In addition, sections of polyvinyl chloride (PVC) dialysis bags were also evaluated by SEM.The S. epidermidis strain RP62A which had been obtained in a previous outbreak of coagulase-negative staphylococcal sepsis at local hospitals was used in these experiments. The strain produced surface slime on exposure to glucose, whereas a nonadherent variant RP62A-NA, which was also used in these studies, failed to produce slime. Strains were grown overnight on blood agar plates at 37°C, harvested from the surface and resuspended in sterile saline (0.85%), centrifuged (3,000 rpm for 10 minutes) and then washed twice in 0.1 M phosphate-buffered saline at pH 7.0. Organisms were resuspended at a concentration of ca. 106 CFU/ml in: a) sterile unused dianeal at 4.25% dextrose, b) sterile unused dianeal at 1.5% dextrose, c) sterile used dialysate previously containing 4.25% dextrose taken from a CAPD patient, and d) sterile used dialysate previously containing 1.5% dextrose taken from a CAPD patient.