Peritoneal Permeability Research Articles

The mechanism of endostar on ascites formation in vivo and in vitro.

e21013 Background: Angiogenesis and vessel hyperpermeability are the two important factors leading to the formation of ascites. Many studies have demonstrated that Endostar strongly inhibits the growth of a variety of murine and xenotransplanted human tumors by suppressing the neovascularization. The study was designed to explore the mechanism of action correlated with tumor ascites in vivo and in vitro. Methods: In vivo, the mice models of tumor ascites with S180 and H22 cell lines were established. Model animals were randomly distributed into 4 groups with 12 mice respectively. 3 groups received different doses of endostar treatment.The control group received 0.9% normal saline. Four mice in each group were undertaken peritoneal capillar permeability experiments. The mice were slowly injected with 0.25 ml of 5 % Evan blue dye from vena caudalis. After 2 h, the mice were killed to collect ascites. The optical density of Evan blue was measured at 540 nm wavelength to indirectly reflect the concentration of Evan blue dye. In vitro, MTT assay was performed to evaluate the proliferation of S180 and H22 cells in the absence or presence of endostar. Tumor cells (1×104cells/well) were incubated with various concentrations of endostar. Invasiveness of Endostar on tumor cells was determinated by Transwell invasion chamber model. Results: In vivo. Results showed that Endostar (dose at 8,16mg/kg) could markedly suppress ascites production and peritoneum permeability, and down-regulated the levels of VEGF, MMP-2 and CD44v6 in blood serum and ascites fluid (P<0.05, respectively). Endostar showed mild apoptosis and cell cycle on S180 and H22 cells (P>0.05). In vitro. Results from incubation of S180 cells and H22 cells with various concentrations of endostar suggested significant inhibition of VEGF, MMP-2 and CD44v6 by ELISA (P<0.05, respectively),and down-regulated the expressions of VEGFmRNA and OPNmRNA by Real-time PCR, and reduced the expressions of OPN, αVβ3 integrin and HIF-1α by Western blot analysis. Conclusions: Those results revealed for the first time that Endostar could profoundly suppress ascites formation through the expressions of VEGF, MMP2, CD44v6, OPN and αVβ3 integrin, rather than induced cells apoptosis and proliferation.

Anti-inflammatory, antiviral and quantitative study of quercetin-3-O- β-D-glucuronide in Polygonum perfoliatum L.

Quercetin-3-O- β-D-glucuronide, isolated from Polygonum perfoliatum L., was evaluated by antiviral efficacy against influenza A virus and anti-inflammatory activity in vivo in mouse, and it was used for quality evaluation of P. perfoliatum L.. In vivo study, oral administration of quercetin-3-O- β-D-glucuronide significantly suppressed ear edema induced by dimethyl benzene and peritoneal permeability induced by acetic acid in mice, and quercetin-3-O- β-D-glucuronide also showed to possess inhibitory activity against influenza A virus (FLUAV). In the present study, additionally, a rapid, simple and sensitive method for quantitative analysis of quercetin-3-O- β-D-glucuronide in P. perfoliatum L. was developed using high performance liquid chromatography (HPLC) coupled with photodiode array detection. The separation was carried out on a Lichrosher-C18 column (250 mm × 4.6 mm, 5 μm) together with a C18 guard column at isocratic elution systems of methanol (A) and 0.05% aqueous phosphoric acid (B) (43:57, v/v) with detection wavelength at 258 nm and column temperature at 30 °C. The method was validated for linearity, repeatability, limit of quantification (LOQ), precision and robustness. The contents of quercetin-3-O- β-D-glucuronide in 28 samples from different regions of China were between 0.06% and 2.09%. The developed analytical method was applied to investigate P. perfoliatum L. and for quality control of the herb.

Kinetic evidence for facilitated peritoneal transport of benzoic acid in rats.

To evaluate the dose dependency in apparent peritoneal permeability (Pd) of benzoic acid as a model compound for a monocarboxylic acid transport system, a kinetic model, which involves changes in the volume and osmolality of the dialysate as well as the diffusion and convection of drugs across the peritoneum, was applied. We compared the Pd value of benzoic acid to that of phenobarbital which is a more lipophilic drug than benzoic acid. The concentration-time courses of phenobarbital in both peritoneal cavity and serum after the intraperitoneal administration with various doses were parallel according to dose, whereas those of benzoic acid varied in a dose-dependent manner. Using the values of unbound fraction (Fu), the value of Pd for unbound drugs was estimated. The Pd values of benzoic acid at 20 micrograms mL-1 was three times the value determined at 1000 micrograms mL-1. We suggest that certain facilitated transport systems constitute the mechanism of enhanced peritoneal membrane permeability of benzoic acid.

Bixa orellana Leaves Extract Inhibits Bradykinin-Induced Inflammation through Suppression of Nitric Oxide Production

Objective: The present study was conducted to assess the anti-inflammatory effect of a crude aqueous extract of Bixa orellana leaves (AEBO) and to examine the possible involvement of nitric oxide (NO) in its anti-inflammatory mechanism. Materials and Methods: The air-dried, powdered leaves were soaked in distilled water (1:20 w/v) at 50°C for 24 h and the supernatant obtained was freeze-dried (yield 8.5% w/w). The dosage was recorded as the mass of extract per kg b.w. of rats in all inflammatory assays (bradykinin-induced paw edema, peritoneal vascular permeability and NO assay). Results: Pretreatment with AEBO for 4 consecutive days exhibited significant inhibitory activity against inflammatory models, the bradykinin-induced hind paw edema model and bradykinin-induced increased peritoneal vascular permeability at both doses in dose-dependent manner. In addition, AEBO was also found to significantly suppress the production of NO at doses of 50 and 150 mg/kg. Conclusion: This study provides scientific data to support the traditional use of B. orellana leaves in treating inflammation. Results from this study suggest that AEBO exerts anti-inflammatory effects. Part of this anti-inflammatory effect may be associated with its antibradykinin activity and may be related to a reduction of the NO production.

Thalidomide Prevents the Progression of Peritoneal Fibrosis in Mice

Thalidomide is clinically recognized as a therapeutic agent for multiple myeloma and has been known to exert anti-angiogenic actions. Recent studies have suggested the involvement of angiogenesis in the progression of peritoneal fibrosis. The present study investigated the effects of thalidomide on the development of peritoneal fibrosis induced by injection of chlorhexidine gluconate (CG) into the mouse peritoneal cavity every other day for 3 weeks. Thalidomide was given orally every day. Peritoneal tissues were dissected out 21 days after CG injection. Expression of CD31 (as a marker of endothelial cells), proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), α-smooth muscle actin (as a marker of myofibroblasts), type III collagen and transforming growth factor (TGF)-β was examined using immunohistochemistry. CG group showed thickening of the submesothelial zone and increased numbers of vessels and myofibroblasts. Large numbers of VEGF-, PCNA-, and TGF-β-positive cells were observed in the submesothelial area. Thalidomide treatment significantly ameliorated submesothelial thickening and angiogenesis, and decreased numbers of PCNA- and VEGF-expressing cells, myofibroblasts, and TGF-β-positive cells. Moreover, thalidomide attenuated peritoneal permeability for creatinine, compared to the CG group. Our results indicate the potential utility of thalidomide for preventing peritoneal fibrosis.

Laparoscopic interventions in children on peritoneal dialysis

Introduction: The benefits of peritoneal dialysis (PD) are multiple. However, it is connected with the risk of numerous complications, both infectious and non-infectious. Laparoscopic interventions in children on PD have seldom been presented. Aim: To analyse laparoscopic interventions in 23 children (mean age 10.2 ±5.2 years) treated with PD. Methods: Performed procedures (30) included: diagnostic (explorative) laparoscopy, laparoscopic replacement of the catheter and laparoscopic recanalisation of occluded catheter. Results: In 29 cases laparoscopy with reduced invasive procedures was completed. During surgery 5 catheters were removed. In 16 cases of catheter malfunction, omental wrap releasing, recanalization and/or reposition was done, including omentectomy in 9 cases. In 6 cases of acute abdomen symptoms, 3 adhesiolysis procedures in bowel obstruction, 2 appendectomies and in 1 case laparoscopic reduction of intussusception were done. There were no intraoperative complications. After surgery PD was continued in 19 children. Catheter survival rate was 261 ±297 days. Laparoscopic surgery had no influence on peritoneal permeability or adequacy of PD treatment. Conclusion: Laparoscopic technique is highly effective in children on PD especially related to catheter malfunction. It is an excellent option that enables restarting of PD shortly after the surgery.

Peritoneal macrophage infiltration is correlated with baseline peritoneal solute transport rate in peritoneal dialysis patients

High baseline peritoneal solute transport rate is reportedly associated with reduced patient and technique survival in continuous peritoneal dialysis (PD) patients. However, the determinants of baseline peritoneal solute transport rate remain uncertain. The aim of this study was to investigate the relationship between peritoneal local inflammation, angiogenesis and systemic inflammation and baseline peritoneal permeability. Peritoneal biopsy specimens from 42 pre-dialysis uraemic patients and 11 control individuals were investigated. Immunohistochemistry for CD68-positive macrophages, chymase- and tryptase-positive mast cells, interleukin-6 (IL-6)-positive cells, CD3-positive T cells, CD20-positive B cells, neutrophils and CD31- and pathologische anatomie Leiden-endothelium (PAL-E)-positive blood vessels in the peritoneum was performed. Baseline dialysate-to-plasma ratio for creatinine (D/P Cr) was determined within 6 months of PD induction. Clinical and laboratory parameters were measured at the time of peritoneal biopsy. Factors associated with peritoneal permeability were assessed by multiple linear regression analysis. Pre-dialysis uraemic peritoneum showed infiltration by CD68-positive macrophages, and mast cells, as compared with controls. Baseline D/P Cr was correlated with density of CD68-positive macrophages (P < 0.001), IL-6-positive cells (P < 0.001), CD31-positive (P < 0.05) and PAL-E-positive blood vessels (P < 0.05) and serum albumin (P < 0.05). However, baseline peritoneal permeability was not correlated with infiltration by mast cells, B cells, T cells, neutrophils, serum C-reactive protein or other clinical factors. On multiple linear regression analysis, the number of CD68-positive macrophages in peritoneum was an independent predictor for baseline peritoneal permeability (P = 0.009). Peritoneal macrophage infiltration is predominant in uraemic patients and is an important factor in predicting baseline peritoneal permeability.

Peritoneal Albumin and Protein Losses Do Not Predict Outcome in Peritoneal Dialysis Patients

Peritoneal clearance of albumin-unlike the transport of small molecules-is defined by both vascular surface area and size-selective permeability. Few studies have supported a positive correlation between peritoneal albumin loss and mortality. The aim of this study was to investigate whether baseline peritoneal loss and clearance of albumin and other proteins is a risk factor of death in peritoneal dialysis patients. All incident peritoneal dialysis patients in our center during the last 15 years were included. Mass-transfer area coefficient of creatinine and peritoneal clearances of albumin, β₂-microglobulin, α₂-macroglobulin, and immunoglobulin G were calculated during a standard peritoneal permeability analysis. The total amount of albumin loss in the dialysate was also calculated. Overall mortality was studied with an intention-to-treat analysis. Two hundred fifty-seven patients were included. High baseline albumin clearance was associated with fast transport status, the presence of peripheral arterial disease, and a high comorbidity index, whereas C-reactive protein levels did not differ from the patients with low albumin clearance. Age, high comorbidity score, C-reactive protein levels >10 mg/L, and a low serum albumin were associated with mortality. Peritoneal albumin clearances and albumin loss were not associated with death in crude and adjusted analysis. Similarly, peritoneal clearances of immunoglobulin G, α₂-macroglobulin, and β₂-microglobulin were not determinants of survival. Baseline peritoneal albumin and protein clearances are associated with signs of comorbidity, but this does not have a measurable effect on patient survival.

Experimental Peritoneal Sclerosis Models Should Not Be Based on Chlorhexidine Gluconate Anymore

Background/Aims: Currently available rodent models of peritoneal sclerosis are not based on clinically relevant factors: renal failure in combination with exposure to bioincompatible fluids. Our aim was to develop a chronic peritoneal infusion model of peritoneal sclerosis in rats with renal failure. Methods: Male Wistar rats underwent a catheter implantation and a 70% nephrectomy. They were randomly divided into three peritoneal infusion groups: chlorhexidine gluconate/ethanol (CGE) + Dianeal (Baxter Healthcare, Castlebar, Ireland), CGE + buffer (Physioneal without glucose; Baxter, Nivelles, Belgium) and Dianeal alone. After 8 weeks a peritoneal permeability test was performed and omental tissue was obtained for morphometrics. Results: The CGE + Dianeal group (n = 6) and CGE + buffer (n = 6) group showed high peritoneal clearances of small solutes and proteins, ultrafiltration failure, impaired free water transport, severe fibrosis and high vessel counts, but the groups did not differ significantly. The Dianeal group (n = 6) showed significantly lower clearances of small solutes and proteins, normal ultrafiltration and sodium sieving, and significantly lower fibrosis scores and vessel counts. Conclusions: Abnormalities seen in peritoneal sclerosis can be induced in a peritoneal infusion model in rats with renal failure. However, the addition of a bioincompatible dialysis solution had no contributing role, probably because the effects were overruled by those of CGE.

Initial high peritoneal transport status is not a predictor of mortality in peritoneal dialysis patients

Objective: Initial high peritoneal permeability in peritoneal dialysis (PD) patients was previously thought to be a poor prognostic factor. We aimed to study the factors that determine the initial transport status and prognosis in PD patients. Methods: This was an observation cohort study that enrolled 551 fresh uremic patients who commenced PD in a single PD center from January 1994 to December 2004. Patients with different initial peritoneal transport status were analyzed and determinants of the initial peritoneal transport status were evaluated. All patients were followed up to investigate the risks of mortality. Results: At the start of PD, only age and sex were determinants of the initial peritoneal transport status upon multiple linear regression analysis. The average duration of the study follow-up was 45.4 ± 29.4 months. In the follow-up, a regression toward mean of transport status was found. About 107 patients died during the observation period. Cox-multivariate analysis revealed only age (RR = 1.06, p < 0.001), comorbidity index (RR = 2.31, p < 0.001), serum albumin (RR = 0.58, p = 0.008), and percentage of lean body mass (RR = 0.97, p = 0.008) to be independent predictors of mortality. Conclusion: We observed that the initial peritoneal transport status is not a determinant factor of long-term mortality. The reason may be due to a consequence of regression toward mean of the transport status. Whether the observed longitudinal regression-to-mean phenomenon change represent any physiologic relevance is hard to define. Further studies on the underlying mechanisms are needed.

The short peritoneal equilibration test in pediatric peritoneal dialysis

The peritoneal equilibration test (PET) is the gold standard method for defining peritoneal membrane permeability and for prescribing peritoneal dialysis (PD) therapy on an individual basis. However, it is laborious, consumes nursing time, and requires many hours to be performed. Therefore, several authors have attempted to validate a short PET protocol, with controversial results. To evaluate the concordance between the 2-h (short) and 4-h (classical) peritoneal equilibrium test, a prospective observational protocol was applied in three PD centers (Mexico, Chile, and Uruguay) between July 1, 2008 and July 31 2009. PET protocol: the night prior to the test, each patient received five exchanges, 1 h each, at the same glucose concentration as previously used. Afterwards, a 2.5% glucose dialysis solution was used for a dwell time of 4 h. Exchange fill volume was 1,100 ml/m2 body surface area. The next morning, the 4-h dwell was drained, and Dianeal 2.5% was infused. Three dialysate samples at 0, 2, and 4 h were obtained. A single blood sample was obtained at 120 min. Creatinine D/P and glucose D/D0 ratios were calculated at hours 0, 2, and 4. Patients were categorized as low, low average, high average, or high transporters according creat D/P and gluc D/D0 results. Pearson and Kappa test were used for numerical and categorical correlations, respectively, and p<0.05 was considered significant. Eighty-seven PET studies were evaluated in 74 patients, 33 males, age 11.1+/-5.05 years old. A positive linear correlation of 92% between 2 and 4-h creat D/P and 80% between 2 and 4-h gluc D/D0 (p<0.001) was founded. The Kappa test showed a significant concordance between creat D/P and gluc D/D0 categories at 2 and 4 h (p<0.001). When analyzing cut-off-value categories, creat D/P was founded to be lower and gluc D/D0 higher than other experiences. This multicentric prospective study strongly suggests that PET obtained at 2 h and 4 h, based on either creatinine or glucose transport, provides identical characterization of peritoneal membrane transport capacity in PD children.

The time course of peritoneal transport parameters in peritoneal dialysis patients who develop encapsulating peritoneal sclerosis

Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD). The first aim was to analyse the risk of EPS in patients who had developed ultrafiltration failure (UFF). The second aim was to identify specific peritoneal transport alterations that distinguish patients with UFF from patients who will develop EPS. All patients of this study were treated with PD between July 1995 and December 2008 in the Academic Medical Center, Amsterdam, the Netherlands. Risk analysis: all PD patients who developed UFF after at least 2 years of PD. Peritoneal transport analysis: all patients who had PD for at least 55 months were included: 12 EPS patients, 21 patients with UFF and 26 patients with normal ultrafiltration (UF). The peritoneal function was measured yearly with a standard peritoneal permeability analysis. UFF was defined as net UF < 400 mL after a 4-h dwell with a 3.86% dialysis solution. Risk analysis: Of the 48 UFF patients, 10 eventually developed EPS. Fifty percent of the patients who continued PD for more than 3 years after the establishment of UFF developed EPS. Peritoneal function analysis: No differences were present for the time courses of solute transport and fluid transport between the EPS and the UFF groups. Overall, the EPS and normal UF groups had lower values for the effective lymphatic absorption rate (ELAR) than the UFF group. The risk of EPS increases with continuation of PD while UFF is present. Transport characteristics are similar between EPS patients and UFF patients without this complication. A constantly low ELAR may distinguish the EPS patients from those with UFF only.

Pathological changes in chronic eosinophilic peritonitis in peritoneal dialysis patient.

We report the pathological findings of the peritoneum in a patient with chronic eosinophilic peritonitis. Peripheral blood eosinophilia was confirmed before insertion of Tenckhoff catheter. Eosinophilic peritonitis continued from the second day after initiation of peritoneal dialysis for 18 months. Pathological findings showed numerous eosinophils in peritoneal blood vessels. Mast cells were also detected in the peritoneum, while neoangiogenesis was not prominent. The highly permeable state of the peritoneal membrane may be due to inflammatory mediators, such as tryptase. Mast cells may be involved in high peritoneal permeability in such patients.

Quantitative evaluation and assessment of peritoneal morphologic changes in peritoneal dialysis patients

Morphologic changes of the peritoneum such as peritoneal fibrosis and vasculopathy develop during peritoneal dialysis (PD). In 2002, Williams et al. reported microscopic characteristics of peritoneal changes in PD patients. These studies pointed out the importance of establishing a global standard for qualitative and quantitative histological evaluations. The objectives of the present study are (i) to verify the methods for assessing peritoneal thickness and classifying vasculopathy in peritoneal specimens using the assessment of Williams et al. and (ii) to propose a simple assessment that reflects clinical features such as PD duration and peritoneal function. Parietal peritoneal samples were obtained from 35 patients that included 27 patients with PD and 8 uraemic patients without PD. In all samples, the maximum and average thicknesses of the submesothelial compact (SMC) zone were measured to assess peritoneal interstitial fibrosis using KS400 imaging analysis. Vasculopathy was also assessed by calculation of patency rates of the vascular lumens using the diameter and area, and by measurement of dimensions of vascular wall hyalinization in each vessel specimen. The median values of maximum and average thicknesses of the SMC zone exceeded 200 μm in uraemic patients without PD treatment. There was a significant relationship between the maximum and average thicknesses of the SMC zone (P < 0.0001). Four to 30 vessels were examined in each participant. Various grades of vasculopathy were observed in each specimen. According to the predominant vasculopathy found in each vessel, the prevalence of serious vasculopathy increased with increasing PD duration. Vascular patency calculated from wall thickness was significantly related to that calculated by the area and to the thickness of hyalinization. Average vascular patency assessed from 5 to 10 vessels in each patient having diameters ranging from 10 to 40 μm was related to PD duration and to peritoneal function (D4/P). A random-points measurement of average SMC thickness provides a descriptive evaluation of the severity of peritoneal fibrosis that minimizes artefacts during processing and avoids human error. In addition, the average patency in post-capillary venules appears to accurately reflect clinical features such as PD duration and peritoneal permeability.

How Can Prognosis for Diabetic ESRD Be Improved?

Although the prognosis of patients who have diabetes and are receiving renal replacement therapy has greatly improved, survival and medical rehabilitation rates continue to be significantly worse than those of nondiabetic patients, mainly because of pre-existing severely compromised cardiovascular conditions. In this scenario, the nephrology community had to do its best in order to offer the best treatment options to these patients using a multifaceted approach. The most common RRT modality in patients with diabetes is still hemodialysis, but it gives rise to a number of clinical problems, in particular difficulties in the management of the vascular access and high frequency of intradialytic hypotension. Recent data suggest that efficient high-flux treatments have the potential of improving morbidity and mortality of diabetics with ESRD. Sodium profiling during the dialysis session may be also of importance in reducing intradialytic hypotension and helping in achieving the prescribed body weight. Patients who have diabetes and are on peritoneal dialysis have to face a progressive increase in peritoneal permeability, loss of ultrafiltration, and peritoneal fibrosis, all phenomena being accelerated in patients with diabetes and ultimately leading to an increased technique failure. However, the two dialytic modalities are comparable in terms of outcomes in the short term.

Early Diagnostic Markers for Encapsulating Peritoneal Sclerosis: A Case-Control Study

Encapsulating peritoneal sclerosis (EPS) is a severe complication of long-term peritoneal dialysis (PD). The aim of this study was to investigate whether dialysate levels of cancer antigen-125 (CA125), K(+), interleukin (IL)-6, and vascular endothelial growth factor (VEGF) are early diagnostic markers of EPS. Therefore, we analyzed the time courses of the above described dialysate markers in EPS patients and controls. Dialysate and serum samples of 11 EPS patients and 31 control patients, all treated with PD for at least 57 months, were longitudinally collected during standard peritoneal permeability analyses. CA125 and IL-6 were measured in dialysate only, K(+) and VEGF were measured in both dialysate and serum. CA125 and IL-6 are expressed as appearance rates (AR). The linear mixed model was used to analyze the time courses. Sensitivity and specificity were calculated based on the results of the last 2 time points. No differences in the time courses of the different markers were present between the groups. For K(+) and VEGF attributed to local production, no differences between the groups were found. However, AR-CA125 was lower during the last 3 years prior to EPS (p < 0.05) and AR-IL-6 tended to be higher 2 years prior to EPS (p = 0.09). The combination of AR-CA125 < 33 U/min and AR-IL-6 > 350 pg/min had a sensitivity of 70% and a specificity of 89% for the development of EPS. Compared to controls, AR-CA125 showed lower values and AR-IL-6 tended to be higher during the last years prior to the diagnosis of EPS. The sensitivity and specificity of the combination of CA125 and IL-6 indicate their potential use for an early diagnosis of EPS.

The Effects of a Dialysis Solution with a Combination of Glycerol/Amino Acids/Dextrose on the Peritoneal Membrane in Chronic Renal Failure

Long-term peritoneal dialysis (PD) with conventional glucose based, lactate-buffered PD fluids may lead to morphological and functional alterations of the peritoneal membrane. It was hypothesized that long-term exposure to a different buffer and a mixture of osmotic agents would cause less peritoneal abnormality. To investigate the effects of long-term exposure to a bicarbonate/lactate-buffered dialysis solution with a mixture of osmotic agents: glycerol 1.4%, amino acids 0.5%, and dextrose 1.1% (= 1% glucose) (GLAD) in a rat model with chronic kidney failure. All rats underwent a peritoneal catheter implantation and a 70% nephrectomy. Thereafter, the rats were randomly divided into 3 groups: GLAD, 3.86% Dianeal (Baxter, Nivelles, Belgium), and buffer (Physioneal without glucose, Baxter). All rats were infused daily for 16 weeks with the appropriate PD fluid. Afterwards, a peritoneal permeability analysis (SPARa) was performed using 3.86% Physioneal in all groups. After the SPARa, the rats were sacrificed to obtain tissue samples for morphometric determinations. Omental tissue was stained with picro Sirius red for assessment of fibrosis and with CD31 for vessel density. GLAD and Dianeal showed faster small solute transport compared to the hypotonic buffer. No differences between the groups were present in ultrafiltration. Dianeal had the lowest value for free water transport and the highest protein clearances. Total triglyceride in plasma was not different between GLAD and the buffer. Vessel density after GLAD exposure (20 V/F) was very similar to the value found for the buffer solution (17 V/F); Dianeal caused a significantly higher value (35 V/F, p < 0.01). Also, the amount of fibrosis was higher in the Dianeal-exposed rats (p < 0.01). Both hypertonic dialysis solutions increased peritoneal solute transport. GLAD exposure was associated with the best preservation of peritoneal morphology. The results of GLAD were very similar to those of the bicarbonate/lactate-buffered solution without osmotic agents. Studies in humans are needed for further assessment of GLAD.

Acute peritoneal dialysis in very low birth weight neonates using a vascular catheter

We report on our experience with acute peritoneal dialysis (APD) in 16 very low birth weight neonates ranging from 24.6 to 30.2 weeks' gestation with a birth weight ranging from 630 g to 1,430 g using a 14-gauge Arrow vascular catheter for APD access. The underlying causes of acute renal failure were: sepsis (7), necrotizing enterocolitis (4), patent ductus arteriosus (3), hydrops fetalis (1), intracranial hemorrhage (3), pulmonary hemorrhage (2), pneumonia (1), and perinatal asphyxia (1). Among 12 patients, the APD was successful for the control of hyperkalemia, fluid overload, and metabolic acidosis. The peritoneal permeability and transport were at their maximum at a short dwell time with rapid exchanges. Complications associated with the APD were: peritonitis (2), leakage (2), hemoperitoneum (1), and hernia (1). During the dialysis, four patients died; there were three episodes of catheter-related complications in these patients. At 60 days after the withdrawal of the APD, 10 patients were alive, and had full recovery of their renal function. Therefore, APD in premature neonates with a 14-gauge Arrow vascular catheter was safe and effective. This procedure helped manage the hemodynamic and metabolic imbalance of acute renal failure and was associated with few complications.

The peritoneal kinetic study performed with hypertonic glucose permits better evaluation of UF capacity and determination of sieving of sodium

The use of solutions containing hypertonic glucose (3.86%/4.25%) has been postulated as the method of choice for study the peritoneal function, and permits a better evaluation of the ultrafiltration (UF) capacity. The aim of our study was to analyze the UF capacity and its relation with the peritoneal permeability and sieving of sodium, performing the peritoneal kinetic study with hypertonic glucose solutions. We performed 184 peritoneal kinetic studies with hypertonic glucose solutions in stable patients on peritoneal dialysis (PD), with a mean time on PD of 16 +/- 22 months. We measured the mass transfer coefficient of creatinine (CrMTC), dialysate to plasma ratio of creatinine (D/PCr), UF capacity and sieving of sodium at 60 minutes (difNa60). The mean values were: CrMTC: 9.1 +/- 4.5 ml/min, D/PCr: 0.71 +/- 0.09, UF 759 +/- 233 ml/4 h and difNa60: 4.7 +/- 2.3. The best multivariate model that predicts the UF capacity included: difNa60, CrMTC, age and time on PD (r = 0.57; p > 0.0001). In patients with UF lower than 600 ml/4 h (Percentil 25) the correlation between UF and CrMTC was lost, but remains the correlation with difNa60 (r = 0.48). The patients with previous peritonitis (n = 38) showed no differences in UF, CrMTC or D/Pcr, but the had lower difNa60 (3.7 +/- 2.8 vs. 4.9 +/- 2.1; p = 0.002) than the remaining patients. The peritoneal kinetic study performed with hypertonic glucose allows to standardize the UF capacity and by determination of sieving of sodium, the early detection of water transport alterations, before the UF capacity and small solutes permeability alteration develops.

Arterial Pulse Wave Velocity and Peritoneal Transport Characteristics Independently Predict Hospitalization in Chinese Peritoneal Dialysis Patients

Cardiovascular disease (CVD) is the most common cause of mortality in chronic peritoneal dialysis (PD) patients. Increased arterial stiffness may be related to a high peritoneal permeability resulting in fluid overload in PD patients. We studied the relations between arterial stiffness, peritoneal transport, and radiographic parameters of systemic fluid overload in a cohort of Chinese PD patients. Prospective cohort study. University referral center. We studied 107 PD patients. Vascular pedicle width and cardiothoracic ratio were measured from a plain postero-anterior chest radiograph. Pulse wave velocity (PWV) was determined at carotid-femoral (C-F) and carotid-radial sites. Peritoneal transport was determined by the dialysate-to-plasma ratio (D/P) of creatinine at 4 hours of dwell. Patients were followed for 9.4 +/- 4.6 months. Duration of hospitalization; actuarial and technique survival. There were no relationships between radiographic measures, arterial PWV, and D/P creatinine. However, both C-F PWV and D/P creatinine were independent predictors of the number of hospitalizations for CVD. None of the parameters correlated with mortality in this study. There were no relationships between radiological parameters of fluid overload, peritoneal transport characteristics, and arterial PWV. Both C-F PWV and D/P creatinine were independent predictors of the number of hospitalizations for CVD. Our result suggests that arterial stiffness and high peritoneal transport each contribute to the development of CVD in this group of patients.