Laparoscopic observations of adhesions between peritoneal dialysis catheters and intraperitoneal organs: A retrospective, observational study.

Laparoscopy provides extensive data for the decannulation of a peritoneal dialysis catheter and is being increasingly used to diagnose encapsulating peritoneal sclerosis. However, there are few reports on the methods of decannulation of peritoneal dialysis catheters. In this study, we examined the laparoscopic findings and postoperative complications of patients undergoing peritoneal dialysis catheter removal. A total of 119 laparoscopic decannulations of peritoneal dialysis catheters were performed between 2003 and 2018 at the Juntendo University Hospital and Juntendo University Nerima Hospital. Laparoscopy was performed during peritoneal dialysis catheter removal by a gastrointestinal surgeon. Patient characteristics such as age, sex, duration of peritoneal dialysis, history of peritonitis and age at the time of peritoneal dialysis termination were assessed. Of these 119 cases, 19 (16.0%) showed adhesion between the peritoneal dialysis catheter and intraperitoneal organs. There were 13 (10.9%) cases involving a tangled omentum, 4 (3.4%) cases involving the small intestine and 2 (1.7%) cases of adhesions extending from the bowels to the abdominal wall. No postoperative complications were associated with the laparoscopic surgery. In these cases, blind decannulation of the peritoneal dialysis catheter may result in injury to the gastrointestinal tract in patients with adhesions. Therefore, we need to pay attention to adhesions between peritoneal dialysis catheters and intraperitoneal organs, and laparoscopy could be a valuable tool in detecting such adhesions and ensuring patient safety.

Impact of Transferrin Saturation and Anemia on Radial Artery Calcification in Patients with End-Stage Kidney Disease.

Background: Arterial calcification is an important factor in determining the prognosis of patients with chronic kidney disease (CKD). Few studies on aortic calcification have involved radial artery calcification (RAC). This study aimed to analyze risk factors for RAC in patients with end-stage kidney disease (ESKD) and investigate the relationship between subsequent cardiovascular events (CVE) and vascular access trouble (VAT). Methods: This cohort study included 64 consecutive patients with ESKD who initiated hemodialysis and underwent a procedure for the creation of a primary radiocephalic arteriovenous fistula (RCAVF). Small arterial specimens were obtained from patients during RCAVF surgery. Tissue samples were stained with von Kossa, and arterial microcalcification was evaluated. We analyzed the association between preexisting arterial microcalcifications, clinical characteristics, CVE, and VAT. Results: In the univariate analysis, RAC patients demonstrated high systolic blood pressure (sBP), low hemoglobin (Hb), and low transferrin saturation (TSAT) (<0.05, <0.05, and <0.05, respectively). In the multivariate analysis, Hb (HR−0.516 (0.278−0.959), p < 0.05), TSAT (HR−0.0012 (0.00000248−0.597), p < 0.05), and sBP (HR−1.037 (1.001−1.073), p < 0.05) were independent risk factors for RAC. The cumulative incidence rate of CVE/VAT was not associated with RAC for one year. Conclusion: RAC was associated with sBP, TSAT, and anemia; however, no association with CVE/VAT was observed.

Coronary Artery Bypass Grafting in Patients with Chronic Kidney Disease: Chronic Kidney Disease Has an Independent Adverse Effect on the Long-Term Outcome of Coronary Artery Bypass Grafting.

We examined short- and long-term outcomes of coronary artery bypass grafting (CABG) in patients with ischemic heart disease and the effect of renal function on these outcomes. We included 2783 patients who underwent primary elective CABG at a single institution between 2002 and 2020 (age: 67.6 ± 10.2 years; male: 2281 male). They were stratified based on their preoperative estimated glomerular filtration rate and underwent off-pump CABG (completion rate, 98.1%); 57.6% cases used bilateral internal thoracic arteries (BITA). In-hospital mortality rate was 1.0%. Logistic regression analysis revealed that low left ventricular function (<40%), but not chronic kidney disease (CKD) severity, was an independent predictive risk factor for postoperative hospital mortality. Significant differences existed in respiratory complications, infections, and hospitalization duration according to CKD severity. Deep sternal wound infection rate was 0.5%. The mean follow-up period was 7.1 (0-18.5) years. Estimated 10-year survival rates were negatively correlated with CKD severity; in the Cox hazard model, severe CKD was an independent predictor of long-term survival. We examined the relationship between preoperative and intraoperative factors and their effects on long-term survival using propensity score matching by dividing the renal function severity into G1-2 and G3-5. Renal function severity, age, and operative time were independent risk factors. No prognostic improvement was observed with BITA grafts; graft patency was superior in the right internal thoracic artery (52/52; 100%) than in the great saphenous vein (48/59; 81.4%) in G5. Post-CABG in-hospital mortality was unrelated to renal function, but CKD severity strongly influenced long-term survival. Operation time was an important predictor of long-term prognosis in patients with impaired renal function. Treatment plans, including graft and anastomosis-site selections, should be designed to shorten the operation time. In conclusion, using the right internal thoracic artery in CABG is more beneficial in patients with CKD and cardiovascular comorbidities.

Predictive Value of 1-Week Postoperative Ultrasonography Findings for the Patency Rate of Arteriovenous Fistula.

INTRODUCTION: Most guidelines in different countries recommend waiting more than 2 weeks for the initial cannulation of an arteriovenous fistula (AVF) after its creation. Although an experienced examiner can subjectively determine if an AVF is ready for early cannulation, there is a lack of objective information to guide whether early cannulation is appropriate or how early cannulation may affect an AVF's primary patency. The current study examined the relationship between the initial cannulation and the prognosis of AVF, considering ultrasonography (US) findings. METHODS: This retrospective observational study enrolled 103 patients with end-stage renal disease who had started hemodialysis therapy from 2013 to 2015 at the Juntendo University Hospital. All patients had been given a primary AVF before or after the initiation of dialysis, had undergone US examinations both before and 7 days after surgery, had initially cannulated the AVF at ≥7 days after surgery, and were observed for over 1 year. RESULTS: The factor associated with the loss of primary patency was a resistance index of brachial artery ≥0.65 on US examination at 7 days after surgery. There was no significant difference in patency rate between the early (within 14 days after surgery) and late initial cannulation groups (≥15 days after surgery). CONCLUSION: Because a resistance index <0.65 on US findings at 7 days after surgery was a good indicator for predicting an excellent patency rate when we performed first cannulation of AVF located in the forearm within 2 weeks after its creation, 1-week postoperative US evaluation may provide crucial information.

Multicenter laparoscopic evaluation of the peritoneum in peritoneal dialysis patients.

Laparoscopic findings have been used to confirm peritoneal degenerations in peritoneal dialysis (PD) therapy. This study evaluated morphological changes in the peritoneum and their clinical relevance in patients undergoing PD. Laparoscopic findings at the rectovesical peritoneum were evaluated and scored using an imaging system at the time of PD catheter removal in this multicenter study. Angiogenesis evaluated by the vascular score (VS), color changes score (CCS), plaque score (PS), PD duration, history of peritonitis, dialysate/plasma creatinine (D/P Cr) levels, and age at PD termination were statistically analyzed. The VS of patients with PD duration more than 96 months was significantly decreased compared with that of the other patients and was negatively correlated with D/P Cr levels at PD termination. The CCS for patients with PD duration more than 96 months were significantly higher than those for the other patients and positively correlated with D/P Cr levels at PD termination. The PS of patients with recurring peritonitis were significantly higher than those of the other patients. Diminished vascularity and increased color changes in the peritoneum may be predictive of D/P Cr levels with peritoneal degradation. Laparoscopic evaluation of the abdominal cavity can provide detailed information about peritoneal injury.

Interventional nephrology: current status and clinical impact in Japan.

BACKGROUND: Current status and clinical significance of interventional nephrology has not been reported from Japan. METHODS: Questionnaires were mailed twice to the directors of all 534 Japanese certificated nephrology training institutions in 2014. The main questions were current performance, categorized annual procedure volume and managers of peritoneal dialysis (PD) access, vascular access (VA) surgery, endovascular intervention, and kidney biopsy. Frequencies of nephrologist involvement between high volume center and low volume center and association between the level of nephrologists' involvement to each procedure and annual procedure volume were examined. RESULTS: 332 (62.2%) institutions answered performance of all procedures and 328 (61.4%) institutions answered all procedure volume. Kidney biopsy, VA surgery, endovascular intervention and PD access surgery were performed by any doctors in 94.2, 96.3, 88.4, and 76.2% and each involvement of nephrologist was 93.9, 54.1, 53.1 and 47.6%, respectively. Cochran-Armitage analyses demonstrated significant increases in all 4 procedure volume with greater management by nephrologists (p < 0.01). Nephrologists involvement to VA surgery associated with procedure volume increase in not only VA surgery, but also PD catheter insertion (p < 0.01) and kidney biopsy (p < 0.05). And nephrologists involvement to PD catheter insertion also associated with surgical volume increase in both VA surgery (p < 0.01) and endovascular intervention (p < 0.05). CONCLUSIONS: Main manager of all 4 procedures was nephrologist in Japan. Each procedure volume increased as nephrologists become more involved. Acquisition of one specific procedure by nephrologist associated with increase not only in this specific procedure volume, but also the other procedure volume.

Pancreatic lipase activity in overnight effluent predicts high transport status in peritoneal dialysis patients.

BACKGROUND: Long-term peritoneal dialysis (PD) causes peritoneal morphological and functional changes, resulting in high transport status featuring increased peritoneal permeability. High transport status is diagnosed by peritoneal equilibration test (PET), a reliable but time-consuming method. We identifed a reliable biomarker in peritoneal effluent to predict high transport status in PD patients. METHODS: We collected peritoneal effluent and serum from 33 PD patients and measured common laboratory test parameters. High transport status was determined by PET if the dialysate/plasma ratio of creatinine at 4h dwell (D/P Cr 4h) was ≥0.81. RESULTS: There were significant correlations between D/P Cr 4h and some laboratory parameters in overnight effluent (pancreatic lipase activity, r=0.65, p<0.001; ß2-microglobulin concentration, r=0.59, p<0.001; IL-6 concentration, r=0.53, p<0.001; and CA125 concentration, r=0.29, p=0.027). In a multivariate logistic regression analysis, the pancreatic lipase activity in overnight effluent was identified as an independent predictor of high transport status even after adjusting for age, PD duration, and glomerular filtration rate [OR=1.43 (95% CI: 1.11-1.83), p=0.005]. CONCLUSIONS: The pancreatic lipase activity in overnight effluent is an independent predictor of high transport status in PD patients.

Predictive factors associated with increased progression to dialysis in early chronic kidney disease (stage 1-3) patients.

BACKGROUND: It has been reported that echocardiographic parameters are independently associated with the progression to dialysis in patients with chronic kidney disease (CKD) (stages 3-5). The objective of the present study was to evaluate whether physical, biochemical, and echocardiographic parameters are associated with the progression to dialysis in early CKD (stage 1-3) patients. METHODS: This retrospective study enrolled 272 CKD patients who underwent echocardiography at the time of diet education, renal biopsy, and the examination of kidney injuries at Juntendo University Hospital, Tokyo, Japan, from 2001 to 2010. All of these CKD patients were classified into stages 1-3. The study patients received regular follow-up at our outpatient clinic in our division. The renal end point was defined as commencement of dialysis. RESULTS: Patients with progression to dialysis were significantly associated with higher levels of left ventricular mass index (LVMI), urinary protein, systolic blood pressure, many kinds of anti-hypertensive drugs, and lower levels of albumin and hemoglobin. In a Cox proportional hazard regression analysis, LVMI [hazard ration (HR) 1.018; 95 % confidence interval (CI) 1.007-1.029; p = 0.002], urinary protein and hemoglobin were independently associated with factors for progression to dialysis in early CKD patients. CONCLUSION: This study of patients in early CKD demonstrated that higher LVMI and urinary protein and that lower levels of hemoglobin in blood were associated with progression to dialysis. LVMI evaluated by echocardiography may identify a high risk of progression to dialysis in early CKD patients.

Impact of anaemia treatment for left ventricular remodelling prior to initiation of dialysis in chronic kidney disease patients: Efficacy and stability of long acting erythropoietin stimulating agents.

AIM: Anaemia is a common complication in patients with chronic kidney disease (CKD), which may initiate or accelerate left ventricular (LV) hypertrophy (LVH). The present study is a retrospective analysis to assess whether anaemia treatment is independently associated with LV remodelling prior to initiation of dialysis in CKD patients. METHODS: Biochemical and physical values were collected over a period of more than 120 days prior to the initiation of dialysis in 27 patients with CKD. The left ventricular mass index (LVMI) was evaluated by echocardiography twice (at the baseline and the follow-up at the initiation of the dialysis period). RESULTS: Patients using long-acting erythropoietin stimulating agents (L-ESA) had the tendency of maintaining higher levels of haemoglobin (Hb) than those using short-acting ESA (S-ESA). Patients using L-ESA showed a more significant improvement in the erythropoietin resistance index (ERI) than those of using S-ESA. In a multivariate regression analysis, the average Hb level for the observational period, the level of Hb at the initiation of dialysis and the use of L-ESA were independently associated factors for the LVMI at the initiation of dialysis. A lower LVMI at the initiation of dialysis and an improvement of the LVMI during the observational period were detected in the highest tertile of average Hb (10.4 g/dL). CONCLUSION: Long-acting ESA was effective and stable when treating anaemia until the start of dialysis. It is important to treat anaemia for the prevention of LV remodelling in CKD patients. These findings have some therapeutic implications for treatment strategies for pre-dialysis patients.

Long-term outcome of encapsulating peritoneal sclerosis (EPS) patients in a single center.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is the most serious complication of peritoneal dialysis (PD) with a high mortality rate. The objective of the present study was to determine the clinical characteristics, the incidence rate, and the long-term outcome of EPS patients compared with control patients. METHODS: Two hundred and seventy patients with end-stage kidney disease were started on PD from 1987 to 2013 in the Juntendo University Hospital. EPS was diagnosed by clinical findings, radiological findings, and macroscopic inspection at the time of laparoscopy or surgical operation. Patient medical records were analyzed retrospectively, including clinical characteristics, laboratory findings, treatment modality, and outcomes. Using a Kaplan-Meier analysis, we compared the survival rate between EPS patients and control PD patients, matched for age, gender, diabetes, and duration of PD. RESULTS: Among 270 PD patients, 13 patients (4.8 %) developed EPS. The mean duration of PD was 120.5 ± 42.8 months. There were no significant difference in demographic findings between EPS and control PD patients. Among the EPS patients, seven patients died, of which four deaths were directly attributed to EPS. All four patients that had had surgical enterolysis were doing well and had no recurrences. No significant difference in the survival rate between EPS and control PD patients was observed in the Kaplan-Meier analysis. CONCLUSIONS: There was no significant difference in the survival rate between EPS patients and control PD patients. It appears that an early diagnosis by laparoscopy and accurate treatment, including surgical enterolysis, might improve mortality.

Oral Astaxanthin Supplementation Prevents Peritoneal Fibrosis in Rats.

BACKGROUND: Preventing peritoneal damage during peritoneal dialysis is critical. Reactive oxygen species (ROS) have an important role in peritoneal damage; however, few studies have investigated this. We aimed to determine the effects of oral astaxanthin (AST) supplementation in a peritoneal fibrosis (PF) rat model. METHODS: Thirty-seven Sprague-Dawley rats were divided into 5 groups: Control 1 (fed a normal diet without stimulation), Control 2 (fed an AST-supplemented diet without stimulation), Group 1 (fed a normal diet with 8% chlorhexidine gluconate [CG] stimulation for 3 weeks), Group 2 (fed a 0.06% AST-supplemented diet with CG stimulation), and Group 3 (fed a 0.06% AST-supplemented diet that was initiated 4 weeks before CG stimulation). Peritoneal fibrosis, vascular proliferation, and fibrosis-related factor expression were examined. RESULTS: Peritoneal thickness was significantly suppressed by AST supplementation. Astaxanthin diminished the number of CD68-, 8-hydroxy-2'-deoxyguanosine (8-OHdG)-, and monocyte chemoattractant protein-1 (MCP-1)-positive cells. Type 3 collagen, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and MCP-1 mRNA expression was significantly lower in Group 3 than in Group 1. Increased transforming growth factor-ß (TGF-ß) and Snail mRNA expression, vascular density, and the number of α-smooth muscle actin (α-SMA)-positive cells were also decreased in Group 3. CONCLUSION: Astaxanthin suppressed PF development through the inhibition of inflammation and oxidation in PF rats. It appears that the anti-oxidative agent AST may be useful for the prevention of peritoneal damage.

Adipose-derived mesenchymal stem cells transplantation facilitate experimental peritoneal fibrosis repair by suppressing epithelial-mesenchymal transition.

BACKGROUND: Prevention or reversal of peritoneal damage is critical in peritoneal dialysis. Although autologous cell transplantation has beneficial effects on tissue repair in various organs, few studies have investigated the effects of transplantation of adipose-derived mesenchymal stem cells (ASCs) on peritoneal fibrosis (PF). Thus, we examined the mechanism of facilitated peritoneal reconstruction induced by ASC transplantation on chlorhexidine gluconate (CG)-induced PF in rats. METHODS: To induce PF in rats, continuous-infusion pumps containing 8 % CG were placed in the abdominal cavity for 21 days. The pumps were removed on day 22 and ASCs were immediately injected into the peritoneal cavity. Morphological alterations and mRNA expression levels of fibrosis-related factors were examined on days 29 and 35. RESULTS: ASC transplantation significantly facilitated peritoneal repair. mRNA expression of tumor necrosis factor-α, interleukin-1ß, monocyte chemotactic protein-1, and epithelial-mesenchymal transition (EMT) markers such as Snail and α-smooth muscle actin were suppressed, whereas that of vascular endothelial growth factor (VEGF) and platelet-derived growth factor-BB (PDGF-BB) were overexpressed after ASC transplantation. Immunofluorescence indicated that some transplanted ASCs expressed VEGF and PDGF-BB and differentiated into vascular cells. CONCLUSIONS: ASC transplantation facilitates peritoneal repair by suppressing EMT and modulating inflammation and angiogenesis during the early phase of tissue repair in experimental PF.

Comparison between the fixation of peritoneal dialysis catheters to the peritoneal wall and the conventional placement technique: clinical experience and follow-up of a new implant technique for peritoneal dialysis catheters.

Peritoneal dialysis (PD) catheters often become severely dislocated, which may lead to malfunction. With the aim of preventing this complication, we have developed a simple method of fixing the catheter downwards in the peritoneal cavity (fixation technique), a technique that does not require a laparoscope. Sixteen patients were implanted using the conventional placement technique and 25 patients were implanted using the fixation technique. The location of the catheter tip was classified from grade 1 (downward, normal) to 5 (dislocated). The frequency of dislocation (defined as the extended time and/or decrease in volume when draining the PD solution) was measured for both the fixation technique and conventional placement technique. There was a significant difference in grade between the fixation technique (2.72 ± 1.01) and conventional technique (3.92 ± 1.31). The time until first dislocation was significantly different between the fixation technique (59.3 ± 48.1 days) and conventional technique (8.8 ± 14.6 days). The time until any dislocation was significantly different between the fixation technique (69.2 ± 41.9 days) and conventional technique (12.9 ± 13.7 days). Complications were not significantly different between the fixation technique and conventional technique. The fixation technique appears to be simple, safe, and useful for preventing severe dislocation and for lengthening the time until dislocation in PD patients.

Paracrine effects of transplanted mesothelial cells isolated from temperature-sensitive SV40 large T-antigen gene transgenic rats during peritoneal repair.

BACKGROUND: The prevention and restoration of peritoneal damage is a critical mission in peritoneal dialysis (PD). Transplantation of mesothelial cells has been suggested to suppress peritoneal injury during PD. Few studies have examined the efficacy and safety of cell transplantation. We evaluated the paracrine effects of mesothelial transplantation during peritoneal repair using immortalized temperature-sensitive mesothelial cells (TSMCs) in chlorhexidine gluconate (CG)-induced peritoneal fibrosis rats. METHODS: Continuous-infusion pumps containing 8% CG were placed into the abdominal cavity for 21 days. After the removal of the pumps, the TSMCs were injected into the peritoneal cavity at Day 22 (Tx-1 group) or 29 (Tx-2 group). Morphological findings and mRNA expressions of regeneration-related factors were examined at Days 22, 29 and 35. RESULTS: Peritoneal thickness was aggravated in the Tx-1 group. Levels of transforming growth factor (TGF)-ß, vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 mRNA in the Tx-1 group at Day 35 were comparable with those at Day 22. The levels of Snail, B-Raf and ERK-1, markers of epithelial to mesenchymal transition and of the RAS/MAPK pathway in the Tx-1 group, were significantly higher than those in the Tx-2 group. TGF-ß and VEGF were produced from the transplanted mesothelial cells and the surrounding cells in the Tx-1 group. CONCLUSION: It appears that the paracrine effect of transplanted mesothelial cells during peritoneal repair is associated with its surrounding condition. It is important to determine the most appropriate time for developing peritoneal repair through mesothelial transplantation.

Campylobacter bacteremia in hemodialysis patients by eating raw meat - the importance of sanitary education.

In 2011, simultaneous, widespread outbreaks of food poisoning by contaminated enterohemorrhagic Escherichia coli in beef, which killed four and hospitalized more than 30 people, occurred in Japan. While the press was widely reporting this disaster, two maintenance hemodialysis patients were suffering from Campylobacter bacteremia by eating undercooked meat. One patient was infected with C. upsaliensis and the other with C. fetus. Although these patients could be successfully treated, they led us to consider the characteristics of C. upsaliensis and C. fetus as opportunistic pathogens, as well as changes in dietary behaviors and food markets. Moreover, they emphasized the need for hemodialysis patients to be not only educated in that they should restrict potassium, phosphate and water intake, but also that they should take care of food sanitation.

Differentiation of bone marrow-derived cells into regenerated mesothelial cells in peritoneal remodeling using a peritoneal fibrosis mouse model.

Marked thickening of the peritoneum and vasculopathy in the submesothelial compact zone have been reported in long-term peritoneal dialysis patients. Bone marrow (BM)-derived cell lines are considered to be useful tools for therapy of various diseases. To clarify the role of BM-derived cells in the peritoneal fibrosis (PF) model, we analyzed several lineages of cells in the peritoneum. BM cells from green fluorescent protein (GFP) transgenic mice were transplanted into naïve C57Bl/6 mice. Chlorhexidine gluconate (CG) was injected intraperitoneally to induce PF. Immunohistochemical analysis was performed with parietal peritoneum using anti-Sca-1 or -c-Kit and -GFP antibodies. Isolated BM cells were also transplanted into the CG-stimulated peritoneum. BM-derived cells from GFP transgenic mice appeared in the submesothelium from days 14 to 42. Both GFP- and stem cell marker-positive cells were observed in the submesothelium and on the surface. Isolated c-Kit-positive cells, transplanted into the peritoneal cavity, differentiated into mesothelial cells. In this study, we investigated whether or not BM-derived cells play a role in the repair of PF and immature cells have the potential of inducing repair of the peritoneum. The findings of this study suggest a new concept for therapy of PF.

Establishment of a peritoneal mesothelial cell line from a transgenic rat harbouring the temperature-sensitive simian virus 40 large T-antigen gene.

BACKGROUND: Establishing a peritoneal mesothelial cell (MC) line in which the native characteristics of primary MCs are constantly maintained in vivo is of great significance for investigating their morphological and functional changes in peritoneal dialysis. We established transgenic (Tg) rats that expressed the temperature-sensitive tsA58 mutant of the simian virus 40 large T-antigen (tsSV40T), which served as a source of immortalized rat cell lines. The cells were immortalized at a permissive temperature of 33 degrees C, although they were differentiated at a non-permissive temperature of 38 degrees C. In this study, we established a novel MC line from tsSV40T Tg rats and evaluated its characteristics. METHODS: MCs were isolated from 8-week-old tsSV40T Tg rats and cloned. MCs from 8-week-old Wistar rats were used as controls. These cells were immunohistochemically and phenotypically evaluated by immunofluorescence, phase contrast and electron microscopy. The production of plasminogen activator inhibitor 1 (PAI-1) from MCs stimulated by tumour necrosis factor-alpha (TNF-alpha) was measured. RESULTS: The tsSV40T MCs showed a cobblestone-like appearance at 33 and 38 degrees C, which was similar to normal primary cultured MCs. Microvilli-like structures were observed on the cell surface by a scanning electron microscope at 33 and 38 degrees C. Wilms tumour-1 and pancytokeratin, as MC markers, were expressed at 33 and 38 degrees C. Following TNF-alpha stimulation, PAI-1 production of tsSV40T MCs was similar to that of normal primary cultured MCs. CONCLUSION: We established a novel, conditionally immortalized MC line that continuously retained the characteristics of primary cultured peritoneal MCs. This cell line might be a useful tool for various types of in vitro biological research on peritoneal dialysis.

Inhibitory effects of matrix metalloproteinase inhibitor ONO-4817 on morphological alterations in chlorhexidine gluconate-induced peritoneal sclerosis rats.

BACKGROUND: The activity of gelatinase, matrix metalloproteinase-2, in effluent was increased in peritoneal dialysis patients with encapsulated peritoneal sclerosis (EPS) and in chlorhexidine gluconate-induced peritoneal sclerosing (PS) animal models. The objective of the present study was to investigate the effect of matrix metalloproteinase inhibitor (ONO-4817), an anticancer agent with anti-angiogenesis and anti-infiltration effects, on the development of peritoneal fibrosis in chlorhexidine gluconate-induced PS rats. METHODS: Forty-five Sprague-Dawley (S-D) rats were intraperitoneally injected with saline as control (n = 15) or with chlorhexidine gluconate (CH) (1.5 ml/100 g) in the CH group (n = 15). ONO-4817 (5 mg/rat) was administered intravenously to CH rats (the ONO-4817 group, n = 15) from initiation to the end of the study. After 22 days of ONO-4817 administration, the rats were sacrificed and the parietal peritoneum was harvested. The gene expressions of transforming growth factor-beta (TGF-beta), alpha-smooth muscle actin (alpha-SMA) and type I collagen in the peritoneum were analysed by the reverse transcription-polymerase chain reaction (RT-PCR). Peritoneal tissues were also evaluated immunohistologically. RESULTS: ONO-4817 significantly inhibited thickening of the submesothelial layer and accumulation of type I collagen in the peritoneum. ONO-4817 also prevented increases of the number of macrophages and blood vessels. The expressions of TGF-beta, alpha-SMA and type I collagen in the peritoneum were markedly suppressed in ONO-4817-treated rats. CONCLUSION: It appears that the administration of the MMP inhibitor ONO-4817 might be a new approach to the amelioration of PS.

Pharmacokinetics of calcitriol and maxacalcitol administered into peritoneal dialysate bags in peritoneal dialysis patients.

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 microg or OCT 10 microg 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 microg OCT were examined in 4 PO 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 microg 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.

Morphologic changes of peritoneum and expression of VEGF in encapsulated peritoneal sclerosis rat models.

BACKGROUND: Simple sclerosis consisted of a thin layer of submesothelial sclerotic tissue in peritoneal dialysis patients. Encapsulated peritoneal sclerosis (EPS) was characterized by thick sclerotic tissue involving vascular alterations in peritoneal dialysis patients. The objective of the present study is to evaluate serial morphologic changes and expressions of angiogenic factors [i.e., vascular endothelial growth factor (VEGF), angiopietin-1 (Ang-1), and angiopoietin-2 (Ang-2)] in EPS rat models. METHODS: Twenty-four rats were given a daily intraperitoneal injection of chlorhexidine gluconate and ethanol dissolved in saline (CH). Nine rats were injected with CH and anti-VEGF neutralizing antibody simultaneously. Quantitative blood vessel evaluation was performed by staining for GS1-lectin. The mRNA expression of VEGF, Ang-1, Ang-2, and their receptors was evaluated by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Immunohistochemical staining was performed in peritoneal vessels using anti-VEGF, Ang-1, and Ang-2 antibodies. Hematopoietic stem cells were detected using anti-CD34 antibody. RESULTS: The vessel area, diameter, and length gradually increased until day 21, and then decreased. VEGF and Ang-2 mRNA expressions gradually increased until day 35. In contrast, Ang-1 peaked at day 21 and then decreased significantly. VEGF blockade improved the experimental EPS. In immunohistochemistry, the vessels stained by VEGF and Ang-2 were detected in subfibrous layer. CD34-positive cells were markedly stained at day 21. CONCLUSION: Neoangiogenesis was observed in a rat model of experimental EPS. VEGF and angiopoietin/Tie system play an important role in the neoangiogenesis in this model. An analysis using this experimental rat model may elucidate the development of EPS in peritoneal dialysis patients.