Papers by Jacek Waniewski
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis
Background It has been shown that hyaluronan (HA) can decrease peritoneal fluid absorption. It is... more Background It has been shown that hyaluronan (HA) can decrease peritoneal fluid absorption. It is not known, however, how various molecular weights and various concentrations of hyaluronan affect peritoneal fluid absorption rate. Methods A study of 4-hour dwells, with frequent dialysate and blood sampling, was performed in male SpragueCawley rats (6 7 rats in each group) with 1311 albumin as an intraperitoneal volume marker. Each rat was infused intraperitoneally with 25 mL of 1.5% glucose solution alone or 1.5% glucose solution containing hyaluronan at various molecular weights (MW -85 kC, 280 kC, 500 kC, and 4 MC) or containing hyaluronan of MW 500 kC at various concentrations (0.01%,0.05%,0.1%,0.5%). Two additional groups were infused with 40 mL of 1.36% glucose dialysate alone or 1.36% glucose dialysate with 0.01 % hyaluronan (MW 500 kC) to test the effect of hyaluronan when high dialysate fill volume was used. Results Addition of 0.01% hyaluronan significantly decreased periton...
Nephrology Dialysis Transplantation, 2018
Nephrology Dialysis Transplantation, 2021
Background and Aims In dialysis patients, urine volume is an easy-to-obtain marker of residual ki... more Background and Aims In dialysis patients, urine volume is an easy-to-obtain marker of residual kidney function but information is lacking of its potential value as an estimate of the renal contribution to total clearance of small solutes. We explored whether correlations of urine volume with different estimations of the residual renal function for urea, creatinine, and phosphorus, could be used to assess renal solute clearances and renal mass removal for investigated solutes. Method In an observational study of 94 non-anuric (urine output ≥ 100 mL per 24 hours) patients (54% men, median age 59 [45 - 68] year, BMI 25.8 [21.4 - 27.7] kg/m2) undergoing automated (n = 59) or continuous ambulatory (n = 35) peritoneal dialysis (PD), we evaluated renal, peritoneal and total (renal plus peritoneal) solute removal (g/week) and clearance (L/week) in relation to urine volume (L/day). Urine volume, renal clearances, ratio of urine solute to serum solute concentration, removed mass of each solut...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1999
Objective To evaluate the convective transport characteristics of glucose and the effect of high ... more Objective To evaluate the convective transport characteristics of glucose and the effect of high glucose and insulin during experimental peritoneal dialysis in rat. Methods Male Sprague–Dawley rats weighing 300 – 400 g were used in this study. Mannitol (5%) was used as osmotic agent. Glucose was added to dialysis solution to yield a concentration of 100 mg/dL (group 1) or 300 mg/dL (group 2). Mannitol solution (5%) containing the same concentration of electrolytes and lactate but without glucose was used as control (group 3). In group 2, blood sugar was maintained at approximately 300 mg/dL by continuous intravenous infusion of 25% glucose solution and 0.9% NaCl solution. A 2-hour dwell study was performed with 30 mL of test solutions. Intraperitoneal volume was calculated by volume marker (18.5 kBq of 131I-human radioiodinated serum albumin, RISA) dilution with corrections made for the elimination of RISA from the peritoneal cavity (KE) and sample volume. The diffusive mass transpo...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1998
Background We reported anomalous transport characteristics of potassium during experimental perit... more Background We reported anomalous transport characteristics of potassium during experimental peritoneal dialysis in rats and suggested that mechanisms of peritoneal potassium transport could be other than simple passive transport. Intracellular transport of potassium in cultured human mesothelial cells was reported to be regulated by three different pathways, such as channels blocked by ouabain, channels blocked by furosemide, and other. Objective To investigate the effect of ouabain on peritoneal potassium and water transport characteristics. Methods A single 4-hour peritoneal dwell was performed in 28 5prague-Dawley rats. To minimize the diffusive transport of potassium, 4.5 mmol/L of KCI was added into conventional dialysis solution with 3.86% glucose [acidic peritoneal dialysis solution (APD)]. To evaluate the effect of the pH of dialysis solution on the transport of potassium and water, 4 mmol/L of NaOH was added into the potassium -containing study solutions [neutral peritoneal...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1999
Background The peritoneal equilibration test (PET) is widely used to classify a patient's per... more Background The peritoneal equilibration test (PET) is widely used to classify a patient's peritoneal transport characteristics. However, PET is laborious and the prediction of fluid removal based on PET is generally poor. It is believed that osmosis by glucose occurs partially through transcellular water channels, resulting in sieving of sodium and decrease of dialysate sodium concentration when using hypertonic glucose dialysate. Objective In this study, we investigated the possibility of using dialysate sodium concentration to classify the patient's peritoneal transport characteristics. Methods A 6-hour dwell study with frequent dialysate and plasma sampling was performed in 46 patients using 2 L of 3.86% glucose dialysate with 1311-albumin as an intraperitoneal volume (IPV) marker. The peritoneal transport of sodium, creatinine, glucose, and fluid was evaluated. Results The dialysate sodium concentration at 240 min (ONa240) significantly correlated with O/P creatinine (r ...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1994
ObjectiveThree transport components are involved in solute transport in peritoneal dialysis: diff... more ObjectiveThree transport components are involved in solute transport in peritoneal dialysis: diffusion, convective transport, and peritoneal reabsorption of dialysate (fluid and solutes). The relative impact of these components on measurable transport characteristics (dialysateto-plasma concentration ratio, diffusive mass transport coefficient, unidirectional clearances) may depend on the direction of solute transport, that is, from blood to dialysate or vice versa. The application of the bidirectional characteristics for the assessment of fluid and solute transport in peritoneal dialysis is reviewed and evaluated.Data SourcesTheoretical analysis as well as computer simulations were applied to discuss available data from our own studies on peritoneal transport as well as from published clinical, experimental, and theoretical studies in the same field.Study SelectionThirty-three relevant clinical and experimental studies as well as theoretical analyses derived from the literature wer...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1993
Objective To evaluate the potential clinical role of amino acids as an osmotic agent. Design The ... more Objective To evaluate the potential clinical role of amino acids as an osmotic agent. Design The peritoneal transport of fluid, amino acids, and other solutes was investigated during a 6–hour single-cycle peritoneal dialysis with PDA 1% versus 1.36% glucose (n=6) or PDA 2.7% versus 3.86% glucose solution (n=9). Patients Fifteen stable nondiabetic continuous ambulatory peritoneal dialysis (CAPD) patients. Results The fractional absorption of the osmotic agents at 6 hours was higher with PDA 2.7% versus glucose 3.86% (p<0.005). The diffusive mass transport coefficient, KeD’ calculated for a period of dialysate isovolemia was higher with PDA 2.7% versus PDA 1% for essential, nonessential (p<0.005), and total (p<0.05) amino acids. The intraperitoneal volume-over-time curves and KqD values for urea, creatinine, glucose, albumin, β2microglobulin, and total protein did not differ between the amino acid solutions and the corresponding glucose solutions. KeD for urea was significant...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1994
Reabsorption of fluid and solutes from the peritoneal cavity poses several problems for the corre... more Reabsorption of fluid and solutes from the peritoneal cavity poses several problems for the correct estimation of peritoneal dialysate volume and ultrafiltration rate with macromolecular volume markers. Although physiological mechanisms of peritoneal reabsorption (direct lymphatic absorption vs reabsorption to the peritoneal tissue) are being currently discussed, many experimental and clinical studies have demonstrated that peritoneal reabsorption of the marker is mainly a bulk “backflow” out of the peritoneal cavity. Theoretical bases for the estimation of peritoneal dialysate volume and cumulative ultrafiltration of fluid including the correction for peritoneal reabsorption are reviewed. A widely applied simplified method which, however, neglects the impact of ultrafiltration on marker concentration is also discussed. The systematic errors involved in the application of the simplified method are usually less than 10% in the standard conditions; however, in specific cases they may ...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1996
Analysis of kinetic studies of peritoneal solute transport involves the need for discrimination b... more Analysis of kinetic studies of peritoneal solute transport involves the need for discrimination between three transport components: diffusion, convective transport, and peritoneal absorption. The description of convective transport in standard clinical conditions of continuous ambulatory peritoneal dialysis (CAPO), as well as in isochratic measurements, has met some problems related to the paradoxical and often anomalous values of sieving coefficient, a parameter that characterizes solute drag with the flow of ultrafiltrate. A possible explanation of some of these results is the time dependence of the transport parameters, which is in contrast to their assumed steadiness. These anomalies as well as the time dependence of the transport parameters are confined more to the standard glucose-based dialysis fluid than to some alternative dialysis fluids. Furthermore, the most striking anomalies have been found for small electrolytes as well as for osmotic agents, which are applied in high...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1999
Four mathematical models and for the description of peritoneal transport of fluid solutes are rev... more Four mathematical models and for the description of peritoneal transport of fluid solutes are reviewed. The membrane model is usually applied for (1) separation of transport components, (2) formulation of the relationship between flow components and their driving forces, and (3) estimation of transport parameters. The three-pore model provides correct relationships between various transport parameters and demonstrates that the peritoneal membrane should be considered heteroporous. The extended threepore model discriminates between heteroporous capillary wall and tissue layer, which are assumed to be arranged in series; the model improves and modifies the results of the three-pore model. The distributed model includes all parameters involved in peritoneal transport and takes into account the real structure of the tissue with capillaries distributed at various distances from the surface of the tissue. How the distributed model may be applied for the evaluation of the possible impact o...
The International Journal of Artificial Organs, 2020
Background:The H+mobilization model has been recently reported to accurately describe intradialyt... more Background:The H+mobilization model has been recently reported to accurately describe intradialytic kinetics of plasma bicarbonate concentration; however, the ability of this model to predict changing bicarbonate kinetics after altering the hemodialysis treatment prescription is unclear.Methods:We considered the H+mobilization model as a pseudo-one-compartment model and showed theoretically that it can be used to determine the acid generation (or production) rate for hemodialysis patients at steady state. It was then demonstrated how changes in predialytic, intradialytic, and immediate postdialytic plasma bicarbonate (or total carbon dioxide) concentrations can be calculated after altering the hemodialysis treatment prescription.Results:Example calculations showed that the H+mobilization model when considered as a pseudo-one-compartment model predicted increases or decreases in plasma total carbon dioxide concentrations throughout the entire treatment when the dialysate bicarbonate ...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 2000
Objective The dialysate concentration of large proteins increases, on average, linearly during th... more Objective The dialysate concentration of large proteins increases, on average, linearly during the whole peritoneal dialysis dwell, and this linear pattern seems to be independent of the rate of ultrafiltration induced by dialysis fluid. However, we observed a high variability of protein kinetics in individual dwell studies. Therefore, we studied the details of the kinetic pattern of peritoneal transport. Design and Methods Kinetics of β2-microglobulin, albumin, and total protein was examined in 23 clinically stable continuous ambulatory peritoneal dialysis patients using Dianeal 3.86% (15 dwell studies) or Dianeal 1.36% (9 dwell studies) dialysis fluid. Dialysate volume was measured using radioisotopically labeled albumin as a volume marker, with corrections for sample volume and absorption of fluid and marker from the peritoneal cavity. The generalized version of the Babb–Randerson–Farrell model was applied to estimate diffusive mass transport coefficient (KBD) and sieving coeffic...
Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis, 1995
Objective To investigate the possible effect of unphysiologically low pH in dialysis fluid on per... more 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...
Frontiers in Physiology, 2019
Background and objective: During peritoneal dialysis (PD), the period of effective net peritoneal... more Background and objective: During peritoneal dialysis (PD), the period of effective net peritoneal ultrafiltration during long dwells can be extended by using the colloidal osmotic agent icodextrin but there are few detailed studies on ultrafiltration with icodextrin solution exceeding 12 h. We analyzed kinetics of peritoneal ultrafiltration in relation to icodextrin and its metabolites for 16-h dwells with icodextrin. Design, setting, participants, and measurements: In 20 clinically stable patients (mean age 54 years; 8 women; mean preceding time on PD 26 months), intraperitoneal dialysate volume (V D) was estimated from dilution of 125 I-human serum albumin during 16-h dwell studies with icodextrin 7.5% solution. Sodium was measured in dialysate and plasma. In 11 patients, fractional absorption of icodextrin from dialysate, dialysate, and plasma amylase and high and low (Mw <2 kDa) Mw icodextrin fractions were analyzed. Results: Average V D increased linearly with no difference between transport types. At 16 h, the cumulative net ultrafiltration was 729 ± 337 ml (range −18 to 1,360 ml) and negative in only one patient. Average transcapillary ultrafiltration rate was 1.40 ± 0.36 ml/min, and peritoneal fluid absorption rate was 0.68 ± 0.38 ml/min. During 16 h, 41% of the initial mass of icodextrin was absorbed. Plasma sodium decreased from 138.7 ± 2.4 to 136.5 ± 3.0 mmol/L (p < 0.05). Dialysate glucose G2-G7 oligomers increased due to increase of G2-G4 metabolites while G6-G7 metabolites and higher Mw icodextrin fractions decreased. In plasma maltose and maltotriose (G2-G3 metabolites) increased while higher Mw icodextrin oligomers were almost undetectable. Dialysate amylase increased while plasma amylase decreased. Conclusions: Icodextrin resulted in linear increase of V D with sustained net UF lasting 16 h and with no significant difference between peritoneal transport types. In plasma, sodium and amylase declined, G2-G3 increased whereas larger icodextrin fractions were not detectable. In dialysate, icodextrin mass declined due to decrease of high Mw icodextrin fractions while low Mw metabolites, especially G2-G3, increased. The ability of icodextrin to provide sustained UF during very long dwells-which is usually not possible with glucose-based solutions-is especially important in anuric patients and in patients with fast peritoneal transport.
American Journal of Nephrology, 2019
Background: Achieving euvolaemia using ultrafiltration (UF) during haemodialysis (HD) without ind... more Background: Achieving euvolaemia using ultrafiltration (UF) during haemodialysis (HD) without inducing haemodynamic instability presents a major clinical challenge. Transcapillary refill is a key factor in sustaining the circulating blood volume (BV) during UF, which is in turn predicted by the rate of refilling. However, absolute plasma refilling rate (PRR), its determinants and variability with UF rate (UFR), have not been reported in the literature. Method: We studied paired HD sessions (n = 48) in 24 patients over 2 consecutive mid-week HD treatments. Plasma refilling was measured using real-time, minute-by-minute relative BV changes obtained from the integrated BV monitoring device during UF. A fixed bolus dilution approach at the start of HD was used to calculate absolute BV. The first control HD session was undertaken with a standard UFR required to achieve the prescribed target weight, while during the second study session, a fixed (high) UFR (1 L/h) was applied, either in t...
Nephrology Dialysis Transplantation, 2019
capacity. Uremic serum of CKD patients may be involved in the development of this sarcopenia. The... more capacity. Uremic serum of CKD patients may be involved in the development of this sarcopenia. The aim of the study was to analyse the effect of uremic toxins on the myogenic and fibrogenic differentiation process in cultured myoblast C2C12. METHODS: Cultured murine myoblast C2C12 cells were used for all experiments. Cells were grown during seven days with 2% horse serum, to promote myogenic differentiation, in the presence or absence of indoxyl sulphate (25mg/ml) and p-cresol (10mg/ml). These doses correspond to the uremic toxins serum levels found in early stages of CDK. Myotube formation was evaluated at several times by immunofluorescence staining of desmin and myosin heavy chain (MHC) using a confocal microscopy. To analyse the expression of myogenic factors, western blot and immunofluorescence staining were performed, using specific mouse antibodies for MHC and myogenin. To assess the expression of fibrogenic factors, western blot and immunofluorescence staining were performed, using specific mouse antibodies for transforming growth factor beta 1 (TGF-b1) and type I collagen. RESULTS: C2C12 myoblasts treated with uremic toxins shown a significant decrease in the number of myotubes at 3 and 7 days compared with cells treated with vehicle. The expression of myogenin, a transcriptional factor involved in myogenic differentiation, increased in control cells after 72 h of culture according with the beginning of myotube formation, whereas myogenin expression was significantly lower in cells treated with uremic toxins at any time. This result suggests that uremic toxins were inhibiting the expression of this factor and consequently the myogenic differentiation. By contrast, uremic toxins treatment increased TGB-b and collagen I expression, two important factors involved in myoblast fibrogenic differentiation. CONCLUSIONS: Uremic toxins serum levels found in early stages of CKD reduce myotube formation in cultured myoblast, disrupting the myogenic differentiation process and promoting fibrogenic factors expression. These results point to a role of uremic toxins impairing the muscle regeneration process, which could be involved in CKD-related sarcopenia and frailty.
Nephrology Dialysis Transplantation, 2019
Care). A Rh sequence is usually 18 sessions during 12 weeks. All patients signed an informed cons... more Care). A Rh sequence is usually 18 sessions during 12 weeks. All patients signed an informed consent form. The efficacy of Rh was evaluated on pain relief and wound healing. RESULTS: 31 patients were prescribed Rh. The indications were ischemic wounds related to peripheral vascular disease (PVD; 19%) and PVD+diabetes (61%), calciphylaxis (10%), cholesterol emboli (7%) and intestine ischemia (3%). Three categories of patients could be individualized. Group A (11 patients), complete Rh sequence with a stop because of significant improvement; Group B (10 patients), premature stop (patient choice (1); stroke (1); surgery (1), amputations (2), sepsis (1), and deaths (4)). Group C (10), still under Rh because of healing delay or developing new wounds. See Table
Nephrology Dialysis Transplantation, 2019
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Papers by Jacek Waniewski