bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased Leukocyte Rolling in Newly Formed Mesenteric Vessels in the Rat during Peritoneal Dialysis
Authors: Zareie Mohammad , Van Lambalgen Anton A. , De Vriese An S. , Van Gelderop Edwin , Lameire Norbert , Ter Wee Piet M. , Beelen Robert H.J. , van den Born Jacob , Tangelder Geert-Jan 
Published: February 2020

Objective Long-term peritoneal dialysis (PD) is associated with the development of functional and structural alterations of the peritoneal membrane. The present study reports the effects of chronic exposure to PD fluid on mesenteric leukocyte–endothelium interactions, using intravital video microscopy. Methods Rats ( n = 7) received 10 mL lactate-buffered 3.86% glucose-containing PD fluid daily during a 5-week period via a subcutaneously implanted mini access port that was connected via a catheter to the peritoneal cavity. In a first control group ( n = 8), catheters were implanted but no fluid was instilled; a second control group ( n = 8) remained untreated. The number of rolling and adherent leukocytes as well as blood flow and other fluid dynamic variables were analyzed in mesenteric postcapillary (diameter 10 – 25 μ) and collecting (diameter 26 – 40 μ) venules. Neovascularization was semiquantitatively assessed after inspection of video images and by light and electron microscopy. Using FITC-labeled albumin, microvascular leakage was examined. Results Rats exposed to PD fluid showed a more than twofold increase in the number of rolling leukocytes ( p < 0.01); the number of adherent leukocytes was not changed. Furthermore, exposure to PD fluid induced severe neovascularization in rat mesentery. No microvascular leakage was observed in the various groups. The observed differences could not be explained by differences in systemic or local hemodynamic parameters or peripheral leukocyte counts, but is most likely associated with new vessel formation. Conclusions Exposure of rat peritoneal membrane to conventional PD fluid for 5 weeks affected local leukocyte–endothelium interactions. In addition, severe angiogenesis was induced, whereas microvascular permeability remained unaltered.
Spatial Distribution of Dialysate in Patients and its Implications to Intradialysate Diffusion
Authors: Hills Brian A. , Birch Seamus , Burke John R. , LaMont Anthony C. 
Published: February 2020

Objective To visualize and quantify the spatial distribution of dialysate in patients on continuous ambulatory peritoneal dialysis (CAPD) and, hence, estimate diffusion times for fluid “pockets” wherever intradialysate concentration gradients may not be dissipated by convective currents. Design Contrast medium was added to the dialysate of three supine CAPD patients before an exchange prior to computed tomographic (CT) scanning. Spatial information in the CT scanner was then downloaded to other computers and processed to produce impressive three-dimensional models of dialysate distribution using “wire frame technology.” Results Models differed between patients but all demonstrated pooling of dialysate in the paracolic gutters, subphrenic space, and, especially, in the pelvic cavity. Some pockets of fluid were almost isolated. Quantitatively, the models can account for over 80% of the volume of the exchange (2.5 L), displaying an effective area of contact of 913 – 1450 cm2 between parietal peritoneum and dialysate. This amounts to only 11% – 21% of the anatomic area, again emphasizing the uneven distribution of dialysate. Ignoring very thin (< 0.1 mm) films of dialysate, the bulk (80%) had mean thicknesses ranging from 1.6 to 1.9 cm. Transcendental equations for bulk diffusion were then applied to these findings to determine a theoretical time for urea of about 2 – 3 hours to half-saturation, or 5 – 7 hours to 80% saturation, in the absence of convective currents. Conclusions The distribution of dialysate within the peritoneal cavity is very uneven, resulting in long diffusion times in fluid pockets wherever convective currents may be minimal. Hence, intradialysate diffusion should not be ignored when modeling peritoneal dialysis.
The Association of Peritoneal Transport Properties with 24-Hour Blood Pressure Levels in Capd Patients
Authors: Tonbul Zeki , Altintepe Lutfullah , Sözlü Çetin , Yeksan Mehdi , Yildiz Alaattin , Türk Süleyman 
Published: February 2020

← Objectives We aimed to investigate the effects of peritoneal transport characteristics on blood pressure (BP) parameters, measured by 24-hour ambulatory blood pressure monitoring (ABPM), and on the development of left ventricular hypertrophy (LVH) in continuous ambulatory peritoneal dialysis (CAPD) patients. ← Design Cross-sectional and prospective design. ← Setting Tertiary-care center. ← Patients 25 CAPD patients (11 male, 14 female; mean age 47 ± 14 years) were included. Mean time on CAPD was 22.9 ± 18 months and all patients had been dialyzed for more than 6 months. The patients were divided into high, high-average, low-average, and low transport groups according to peritoneal equilibration test results. ← Main Outcome Measures Daytime and nighttime systolic and diastolic BP and left ventricular mass index among the different peritoneal transport groups; changes in BP parameters before and after increase in ultrafiltration. ← Results On 24-hour ABPM records, 13 patients (52%) were found to be hypertensive. Both mean systolic and diastolic BP were significantly increased in high-transporter groups compared to low transporters in both daytime and nighttime BP parameters. Left ventricular mass index was higher in high transporters compared to low transporters, without reaching statistical significance: 160 ± 23 vs 119 ± 41 g/m2, p > 0.05. Following increase in ultrafiltration, mean systolic (145 ± 13 vs 128 ± 5 mmHg, p < 0.001) and diastolic (96 ± 10 vs 81 ± 3 mm Hg, p < 0.001) BP decreased, and BP levels returned to normotensive levels in 6 (46%) of the 13 hypertensive patients, requiring discontinuation of antihypertensive drugs. ← Conclusion Improvement in volume status resulted in a decrease in both daytime and nighttime BP. Differences in peritoneal transport properties were associated with the development of hypertension and LVH.
Prolonged Stability of Antimicrobial Activity in Peritoneal Dialysis Solutions
Authors: Dooley David P. , Tyler J. Robert , Wortham William G. , Harrison Linda S. , Starnes William F. , Collins George R. , Ozuna Irene S. , Violet Patty L. , Ward John A. 
Published: February 2020

← Objective To evaluate the stability of the antimicrobial chemical and bioactivity of gentamicin, vancomycin, and gentamicin and vancomycin in combination, and the stability of the bioactivity of ceftazidime, admixed in standard peritoneal dialysis solutions and then maintained over a 14-day period at room temperature or under refrigeration. ← Setting Peritoneal dialysis center and microbiology laboratory at a military, teaching medical center. ← Measurements Standard peritoneal dialysate bags admixed with gentamicin, vancomycin, gentamicin and vancomycin in combination, or ceftazidime were stored at either 4°C or 20°C for 14 days. Sequential aliquots were withdrawn and assayed for antibiotic activity by bioassay and, except for ceftazidime, immunoassay for chemical activity. The bioassay was performed using a standardized Kirby–Bauer disc method. Significance was determined by ANOVA and, where the effect size was significant at the p < 0.05 level, the application of the paired t-test or the Wilcoxon signed rank test to the difference in activity between the first and last samples. ← Results Antibiotic concentration by immunoassay did not significantly deteriorate over 14 days for vancomycin or gentamicin when either room temperature or refrigerated samples were studied. By bioassay, gentamicin and ceftazidime, but not vancomycin, lost moderate but significant activity over 14 days when refrigerated bags were assayed (except for an insignificant decrement in gentamicin in the combined vancomycin and gentamicin bags). Bags stored at room temperature, in general, lost significant bioactivity over 14 days, but to levels where clinical efficacy would still be expected. The vancomycin bioassay performed on the combination bags demonstrated a remarkably enhanced bioactivity, presumably reflecting synergy with gentamicin. ← Conclusion These data indicate that the study antibiotics admixed with peritoneal dialysis fluids retain stable chemical activity, whether refrigerated or kept at room temperature, for at least 14 days. A moderate decrement in bioactivity occurred for study antibiotics when stored either refrigerated or at room temperature over 14 days, although clinically significant levels were maintained. The clinical significance of a possible synergy between vancomycin and gentamicin is yet to be determined.
Single Exposure of Mesothelial Cells to Glucose Degradation Products (GDPs) Yields Early Advanced Glycation End-Products (AGEs) and a Proinflammatory Response
Authors: Welten Angelique G.A. , Schalkwijk Casper G. , Ter Wee Piet M. , Meijer Sybren , Van Den Born Jacob , Beelen Robert J.H. 
Published: February 2020

← Background Fluids commonly used for peritoneal dialysis (PD) have a low pH and a high glucose content. Furthermore, heat sterilization of dialysis fluids degrades some of the glucose into glucose degradation products (GDPs), such as methylglyoxal (MGO) and 3-deoxyglucosone (3-DG). Mesothelial cells (MCs) form the first line in the peritoneal cavity and are constantly exposed to these nonphysiological conditions. Since MCs play an important role in the regulation of inflammatory responses in the peritoneal cavity, we studied the kinetics of MC uptake of highly purified GDP species, along with their effect on various cellular biological and immunological parameters. ← Methods Methylglyoxal and 3-DG were purified and added to MC cultures. Complexing to medium components or uptake by MCs was analyzed over time by HPLC of the culture supernatant and by immunocytochemistry of MCs for MGO-modified proteins. Furthermore, MCs were exposed to a single dose of MGO or 3-DG and analyzed for apoptosis, proliferation by MTT assay, and [3H]-thymidine incorporation. Incorporation of [35S]-methionine was determined in order to analyze de novo protein synthesis. Expression of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1), CD44, and vascular cell adhesion molecule-1 (VCAM-1) was analyzed by cell-bound ELISA. Effects of MGO and 3-DG on cytokine production were also analyzed. ← Results Substitution of MGO and 3-DG in culture medium resulted in a spontaneous decrease in MGO over time, whereas 3-DG levels decreased minimally. The concentration of these GDPs was more reduced in the presence of MCs, indicating binding to and/or uptake by MCs of these GDPs. Mesothelial cells that had been cultured in the presence of MGO showed positive staining with a monoclonal that specifically recognizes MGO-modified proteins, demonstrating complexing to mesothelial cellular proteins. Cell-bound ELISA showed a two- to threefold induction of expression of VCAM-1 by MGO and 3-DG; the expression of ICAM-1 and CD44 was not changed. Mesothelial cells showed a twofold increase in interleukin (IL)-6 and IL-8 production after exposure to 3-DG. Furthermore, incubation with MGO and 3-DG induced apoptosis and reduced the proliferation of cells, but did not influence protein synthesis. ← Conclusions In the current report we demonstrate that MCs take up MGO and 3-DG and form early advanced glycation end-products. Upon short exposure to a single GDP, MCs react with enhanced cytotoxic damage and a proinflammatory response, evidenced by increased VCAM-1 expression and elevated production of IL-6 and IL-8.
Sources of Staphylococcus Aureus for Patients on Continuous Ambulatory Peritoneal Dialysis
Authors: Herwaldt Loreen A. , Boyken Linda D. , Coffman Stacy , Hochstetler Linda , Flanigan Michael J. 
Published: February 2020

← Objective This study was designed to determine whether family members and health care workers are a source of Staphylococcus aureus for patients on peritoneal dialysis. ← Design Over 36 months, cultures were obtained from the nares of patients, family members that cared for the patients’ catheters, and health care workers in a dialysis unit. Pulsed-field gel electrophoresis was performed on all S. aureus isolates. ← Setting A university-based peritoneal dialysis program. ← Participants 74 patients, 32 family members, and 17 health care workers. ← Interventions None. ← Main Outcome Measures The number of patients that acquired S. aureusstrains during the study period. ← Results Of the 48 patients whose initial nares cultures were negative, 7 (15%) acquired S. aureus strains. Overall, 24 of 53 (45%) patients that had 2 or more cultures obtained during the study gained strains. Potential sources were not identified for strains gained by 11 (46%) patients. Five patients appeared to acquire their strains from family members; however, other patients also shared related strains; 8 patients acquired strains shared by other patients. ← Conclusions Family members and other patients appeared to be important sources of S. aureus for patients on peritoneal dialysis. Health care workers that carry S. aureus transiently may be important intermediaries. Good hand hygiene is essential to prevent transmission of S. aureus to these susceptible patients.
Suitable Dialytic Indicators for Pediatric Peritoneal Dialysis Patients: The Alternative to Creatinine Clearance
Authors: Ishikura Kenji , Hataya Hiroshi , Ikeda Masahiro , Honda Masataka 
Published: February 2020

← Objective Owing to the discord between body weight and body surface area (BSA), creatinine clearance (CCr) is predisposed to be small in pediatric patients on peritoneal dialysis (PD). Alternatively, Kt/V creatinine (Kt/V creat), which is normalized to total body water (TBW) rather than BSA, could be a better dialytic indicator. In this study, the efficiency of dialysis and the nutritional status of pediatric patients on chronic PD were examined, and the utility of dialytic indicators was evaluated. ← Patients and Methods 49 patients under 20 years old, in stable condition, and on PD were analyzed. Weekly total Kt/V of urea (Kt/V urea), CCr, Kt/V creat, and normalized protein equivalent of nitrogen appearance (nPNA) were measured for all patients and for patients under 6 years old. The target value was 2.0/week for Kt/V urea and 60 L/week/1.73 m2 for CCr, as recommended by the Kidney Disease Outcomes Quality Initiative guidelines. The target value for Kt/V creat was set as 1.52/week, using a male model with a height of 170 cm and a body weight of 65 kg. ← Results The mean values of delivered Kt/V urea, CCr, Kt/V creat, and nPNA (and proportion of patients that achieved each target value) for all patients were 2.25 ± 0.57/week (67.4%), 53.8 ± 19.3 L/week/1.73 2m (26.5%), 1.83 ± 0.73/week (65.3%), and 1.11 ± 0.42 g/day, respectively. The values for patients under 6 years old were 2.38± 0.26/week (90.0%), 45.9 ± 12.8 L/week/1.73 2m (10.0%), 1.94 ± 0.51/week (90.0%), and 1.52 ± 0.67 g/day, respectively. Stepwise multiple regression analyses revealed that the relationship between CCr and Kt/V urea was affected by the patient's age. ← Conclusions Our pediatric patients achieved the recommended target value of Kt/V urea. At the same time, the nPNA results reflected the patient's status well. However, CCr appeared to be inappropriate as an indicator for patients under 6 years old. Kt/V creat is suggested to be a better dialytic indicator for these patients.
Staphylococcus Aureus Prophylaxis and Trends in Gram-Negative Infections in Peritoneal Dialysis Patients
Authors: Piraino Beth , Bernardini Judith , Florio Tracey , Fried Linda 
Published: February 2020

Objective To examine gram-negative exit-site infection and peritonitis rates before and after the implementation of Staphylococcus aureus prophylaxis in peritoneal dialysis (PD) patients. Design Prospective data collection with periodic implementation of protocols to decrease infection rates in two PD programs. Patients 663 incident patients on PD. Interventions Implementation of S. aureus prophylaxis, beginning in 1990. Main Outcome Measures Rates of S. aureus, gram-negative, and Pseudomonas aeruginosa exit-site infections and peritonitis. Results Staphylococcus aureus exit-site infection and peritonitis rates fluctuated without significant trends during the first decade (without prophylaxis), then began to decline during the 1990s subsequent to implementation of prophylaxis, reaching levels of 0.02/year at risk and zero in the year 2000. Gram-negative infections fell toward the end of the 1980s, due probably to the implementation of better connectology. However, there have been no significant changes for the past 6 years. There was little change in P. aeruginosa infections over the entire time period. Pseudomonas aeruginosa is now the most common cause of catheter infection and catheter-related peritonitis. Conclusions Prophylaxis against S. aureus is highly effective in reducing the rate of S. aureus infections but has no effect on gram-negative infections. Pseudomonas aeruginosa is now the most serious cause of catheter-related peritonitis.
Is the Peritoneum a Significant Transport Barrier in Peritoneal Dialysis?
Authors: Flessner Michael , Henegar Jeffrey , Bigler Steven , Genous Lori 
Published: February 2020

Objectives The anatomic peritoneum is often considered equivalent to the barrier between the dialysate and the blood, and is also called “the peritoneal membrane.” Our hypothesis is that the normal peritoneum is not a significant barrier to solute or water flow. The goal of this study was to explore the effects of alteration of the anatomic peritoneum on the transperitoneal transport of water and solute. Design In vivo transport experiments were carried out in control and treated rats. Treatments consisted of frequent mixing of the peritoneal solution versus no mixing, drying the peritoneum prior to the experiment, or selective removal of the entire peritoneum. Transport experiments were carried out via a plastic chamber affixed to the parietal peritoneum. After measuring solute transport or osmotically induced filtration, the tissue underlying the chamber was collected and stained for histology. Results Mixing the chamber solution every 5 minutes versus no mixing over 90 minutes did not result in a significant change in the mass transfer coefficient for mannitol (MTCmannitol, n = 14, p > 0.25). Drying the peritoneum prior to the transport experiment did not significantly alter the MTC of albumin or mannitol ( n = 17, p > 0.6; n = 19, p > 0.1, respectively). Manual drying did not remove or significantly alter the apparent peritoneal coating on the surface of the mesothelium. Removal of the entire peritoneum did not significantly alter the osmotically induced volume flux from the tissue, nor did it change the MTCmannitol ( n = 9, p > 0.9; n = 9, p > 0.4, respectively). Conclusions Mixing of the solution directly over the tissue, manual drying of the peritoneum, or removal of the entire peritoneum does not result in significant alterations in transport. We conclude that the anatomic peritoneum is relatively unimportant as a physical transport barrier in peritoneal dialysis.
Disturbed Appetite Patterns and Nutrient Intake in Peritoneal Dialysis Patients
Authors: Wright Mark , Woodrow Graham , O'Brien Siobahn , King Neil , Dye Louise , Blundell John , Brownjohn Aleck , Turney John 
Published: February 2020

Objective Malnutrition is common among peritoneal dialysis (PD) patients. Reduced nutrient intake contributes to this. It has long been assumed that this reflects disturbed appetite. We set out to define the appetite profiles of a group of PD patients using a novel technique. Design Prospective, cross-sectional comparison of PD patients versus controls. Setting Teaching hospital dialysis unit. Patients 39 PD patients and 42 healthy controls. Intervention Visual analog ratings were recorded at hourly intervals to generate daily profiles for hunger and fullness. Summary statistics were generated to compare the groups. Food intake was measured using 3-day dietary records. Main Outcome Measures Hunger and fullness profiles. Derived hunger and fullness scores. Results Controls demonstrated peaks of hunger before mealtimes, with fullness scores peaking after meals. The PD profiles had much reduced premeal hunger peaks. A postmeal reduction in hunger was evident, but the rest of the trace was flat. The PD fullness profile was also flatter than in the controls. Mean scores were similar despite the marked discrepancy in the profiles. The PD group had lower peak hunger and less diurnal variability in their hunger scores. They also demonstrated much less change in fullness rating around mealtimes, while the mean and peak fullness scores were little different. The reported nutrient intake was significantly lower for PD. Conclusion The data suggest that PD patients normalize their mean appetite perception at a lower level of nutrient intake than controls, suggesting that patient-reported appetite may be misleading in clinical practice. There is a loss of the usual daily variation for the PD group, which may contribute to their reduced food intake. The technique described here could be used to assess the impact of interventions upon the abnormal PD appetite profile.
Histologic Change of Peritoneal Membrane in Relation to Adequacy of Dialysis in Continuous Ambulatory Peritoneal Dialysis Patients
Authors: Savidaki Irini , Karavias Dionisios , Sotsiou Florentia , Alexandri Sotiria , Kalliakmani Pantelitsa , Presvelos Dimitrios , Papachristou Evagelos , Goumenos Dimitrios S. , Vlachojannis Jannis G. 
Published: February 2020

Background Long-term exposure of peritoneal membrane to bioincompatible dialysis solutions leads to structural changes and loss of ultrafiltration capability. Objective We studied the possible relationship between histologic change and the transport characteristics of peritoneal membrane and adequacy of dialysis in continuous ambulatory peritoneal dialysis (CAPD) patients. Patients and Methods The study included 18 CAPD patients (11 men, 7 women) who underwent a peritoneal biopsy either at initiation of treatment (group A, n = 9) or after a mean of 4 years on CAPD (group B, n = 9). The morphologic changes in the mesothelial cells and the vascular compartment and the thickness of the submesothelial collagenous zone were estimated and compared with observations from 6 patients with normal renal function who underwent biopsy of the parietal peritoneum during abdominal surgery. The relationship of the observed changes in CAPD patients to results from a peritoneal equilibration test (PET) and to adequacy of dialysis [total weekly creatinine clearance (CCr) and Kt/V urea] were also investigated. Results The main histologic changes in both groups of patients were loss of mesothelial cells and decrease in the normal mesothelial surface, thickening of the submesothelial collagenous zone, and presence of vascular hyalinosis. The thickness of the submesothelial collagenous zone in both groups of patients was significantly greater than that found in controls (410 μm and 580 μm vs 50 μm, p < 0.05). Although no significant difference was found between morphologic change in the peritoneal membrane of uremic patients starting on CAPD and those who had been on peritoneal dialysis (PD) for a mean period of 4 years, a trend was observed toward more severe lesions in the latter patients. The PET, CCr, and Kt/V urea were not significantly different in the two groups of patients. Those parameters also showed no significant changes when examined at initiation of CAPD and after a mean of 4 years of PD in the same patients (group B). No significant correlations were observed between the histologic changes and the PET, CCr, or Kt/V in both groups of patients. Conclusions Significant structural changes are observed in the peritoneal membrane of uremic patients, and those changes become worse with CAPD treatment. Structural changes are not followed by functional changes during the first 4 years on CAPD.