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Biomedical subjects

Dimitrios G Oreopoulos

Publications and source records attributed to Dimitrios G Oreopoulos.

At least 37 records · Page 2Linked to original sources
PubMed2004

Is there a need for low sodium dialysis solution for peritoneal dialysis patients?

Cardiovascular disease is a leading cause of death in patients with end-stage renal disease (ESRD), and hypertension and volume expansion are highly prevalent in long-term peritoneal dialysis (PD) patients. The ADEMEX study made it clear that increased small-solute clearance does not lead to better outcomes. To manage the problem, current clinical practice uses strategies of dietary salt and fluid restriction, diuretics, antihypertensive drugs, icodextrin, extra day dwells, and (as a last resort) PD combined with hemodialysis (HD) or switch to HD. Nevertheless, the prevalence of hypertension remains alarmingly high. In this article, we briefly discuss the therapeutic measures currently available for treating hypertension and volume overload in PD patients, the limitations of those measures, and the possibility of increasing sodium removal by reducing the dialysate sodium level.

Antihypertensive Agents↗
PubMed2004

Serum levels of prostate-specific antigen and vitamin D in peritoneal dialysis patients.

Measuring the free:total ratio of prostate-specific antigen (f/t-PSA) can improve the specificity of single-serum PSA values, distinguishing between benign prostatic hyperplasia (BPH) and prostatic carcinoma (PCa) in men over the age of 50. Additionally, clinical trials have shown that dihydroxyvitamin D3 can slow the rate of PSA rise in PCa patients. However, little is known regarding the applicability of those findings in men undergoing chronic peritoneal dialysis (CPD). In the present study, we investigated the prevalence of increased serum PSA levels among CPD patients and correlated those values with serum levels of vitamin D [25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3]. We undertook a cross-sectional study of 71 male CPD patients without a known history of prostate cancer from 24 centers in Canada, Greece, and Turkey. All of the patients were more than 50 years of age. In these patients, we measured serum concentrations of PSA, free PSA (f-PSA), total PSA (t-PSA), prostate alkaline phosphatase (PAP), 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and intact parathyroid hormone (iPTH). We recorded serum PSA levels < 4 ng/mL in 62 patients (87.3%, group A) and levels > 4 ng/mL in 9 patients (12.7%, group B). The f/t-PSA ratio was < 0.25 in 16 patients (22.5%). Group B patients were older than those in group A (median: 73 years vs. 65 years, p < 0.01) and had a lower body weight (median: 66.5 kg vs. 76.7 kg, p < 0.05). We observed no statistically significant difference between the two groups for serum 1,25-dihydroxyvitamin D3 (median: 9.8 ng/mL vs. 10.1 ng/mL) or 25-hydroxyvitamin D3 (8 ng/mL vs. 8.2 ng/mL) levels. Also, we observed no correlation between vitamin D levels and f/t-PSA, but iPTH levels were significantly higher in group A (200.5 pg/mL vs. 61.2 pg/mL, p < 0.04). Also, serum PAP levels correlated significantly with PSA (r = 0.49, p = 0.01) and with f-PSA (r = 0.56, p = 0.000). Our results showed no clear relationship between vitamin D and serum levels of PSA or-of f/t-PSA in PD patients. However, further studies are needed to better define the uses of these PSA markers in PD patients because, in such patients, other relevant factors might be implicated in their predictive value.

Aged↗
PubMed2003

Glucose-induced changes in the phenotype of human peritoneal mesothelial cells: effect of L-2-oxothiazolidine carboxylic acid.

BACKGROUND: During peritoneal dialysis, mesothelial cells are chronically exposed to high concentrations of glucose. Therefore, the cytotoxic effect of glucose may alter the function and reactivity of these cells. METHODS: For 4 weeks, human peritoneal mesothelial cells were cultured in vitroin medium supplemented with 45 mM glucose or 45 mM mannitol or with 45 mM glucose and 1 mM L-2-oxothiazolidine-4-carboxylic acid (OTZ), the latter being a precursor for glutathione synthesis. Peroxidation of the mesothelial cell lipids, synthetic activity and reaction of these cells to peritoneal dialysis fluids were studied. RESULTS: In contrast to mannitol, glucose enhanced the peroxidation of the cellular lipids (+65%, p < 0.01) an effect that was prevented by OTZ. Synthesis of hyaluronan and vascular endothelial growth factor was reduced in mesothelial cells treated with glucose by 36% (p < 0.01) and 44% (p < 0.05), respectively; both glucose effects were reversed when cells were incubated with glucose plus OTZ. Monocyte chemoattractant protein-1 synthesis by cells exposed to glucose was increased by 31% (p < 001), and again that effect was prevented by OTZ. Glucose and mannitol stimulated synthesis of fibronectin (+32%, p < 0.05). Mesothelial cells chronically exposed to glucose became activated after subsequent exposure to the dialysis fluid, as reflected by the increased release of interleukin (IL)-6, in contrast to control mesothelial cells, in which IL-6 synthesis was suppressed. CONCLUSIONS: Chronic exposure of mesothelial cells to glucose changes their synthetic activity and their reaction after exposure to dialysis fluids. Some of these effects are prevented by OTZ, which suggests that glucose-induced free radicals are responsible for a change in mesothelial cell phenotype under the conditions of peritoneal dialysis.

Carrier Proteins↗
PubMed2003

Differences in survival on peritoneal dialysis between oriental Asians and Caucasians: one center's experience.

BACKGROUND: Recently it has been suggested that the survival of dialysis patients may differ among different races. Both registry data and data from Asian countries indicates that Asians on peritoneal dialysis may survive longer than their Caucasian counterparts. In the present study, we performed a detailed analysis of survival differences between oriental Asians and Caucasians on peritoneal dialysis in our multiethnic, multicultural program. METHODS: Retrospectively we analyzed the survival data for patients who started peritoneal dialysis after January 1, 1996 and before December 31, 1999, in our hospital. They were followed for at least for two years. Excluded from the present analysis were those who survived for less than three months on peritoneal dialysis. The patient demographic characteristics, comorbidities, and residual renal function at the start of dialysis were collected. Indices for adequacy of dialysis were collected 1-3 months after the initiation of dialysis. Actuarial survival rates were determined by the Kaplan-Meier method. The Cox proportional hazards model was used to classify risk factors for a high mortality. RESULTS: There were 87 Caucasians and 29 Oriental Asian peritoneal dialysis patients. No differences were found in age, gender, primary renal disease, and residual renal function between the two groups. The Caucasians had significantly higher body surface area and urea volume and higher incidence of cardiovascular diseases. Even with slightly higher dialysis dose, the peritoneal creatinine clearance was significantly lower among the Caucasians than among Asians. There was no difference in the peritoneal D/P value between the two groups. However, compared to the Caucasians, the 24hr peritoneal fluid removal and total fluid removal volumes were significantly lower in the Asian patients. The one, two, three and four year survival rates were 95.8%, 91%, 86% and 80% for Asians and 91.3%, 78.1%, 64.7% and 54.1% for Caucasians. Significant predictors for a higher mortality were the presence of cardiovascular disease (42% increase in risk), Caucasians (39% increase in risk) and older age (37% increase in risk for age older than 65). CONCLUSIONS: Our study confirms that oriental Asians on peritoneal dialysis patients survive much longer than their Caucasian counterparts; this was partly due to the fact that Asian patients have less cardiovascular disease when they began peritoneal dialysis. Due to their smaller body size, the Asians tended to have a higher peritoneal small solute clearances despite their smaller dialysis doses, indicating that, to achieve the same solute clearance targets, Asians need a smaller dialysis dose compared to Caucasians.

Asian People↗
PubMed2003

Fatigue in chronic peritoneal dialysis patients.

Fatigue is a common complaint in long term dialysis patients that may influence their quality of life. The present study was carried out in order to evaluate the prevalence and course of fatigue in a group of chronic PD patients and to find the possible factor(s) related to its development. We retrospectively reviewed 100 charts of the patients previously on PD. The presence or absence of fatigue in the 1st and last clinic visits and the 1st and 2nd changes in fatigue state were studied according to the monthly clinical records of the primary nurses. Data regarding dialysate volume, urine volume, weekly erythropoietin (EPO) dose, hemoglobin, hematocrit, blood urea, serum creatinine, residual renal creatinine and urea clearances, dialysate to peritoneal creatinine ratio (D/P Cr), total weekly Kt/V and total creatinine clearance/1.73 m2 body surface area (TCrCl) were collected. Fifty-five patients were male and 45 female. The mean age at the 1st clinic visit was 61.3 +/- 16 years. At the 1st visit 55 patients had fatigue and 45 did not. In 32 of the 55 patients fatigue disappeared after a mean duration of 7.9 +/- 8.4 months and in 31 of the 45 patients fatigue appeared after a mean duration of 8 +/- 6.8 months. So at the last visit the frequency of fatigue increased significantly from 55% to 67% (p < 0.001). In patients with fatigue the mean age and female percentage were higher (64.2 +/- 14.1 vs 57.8 +/- 17.6, p = 0.05 and 1.2 vs 0.5, p < 0.05 respectively), mean hemoglobin concentration was lower (104.4 +/- 14.7 vs 110.6 +/- 14.2 g/L, p < 0.04) and mean EPO dose was higher (6379.6 +/- 7142 vs 3395.4 +/- 4337.8 units/week, p < 0.02) at the 1st clinic visit. EPO dose was also higher in patients with fatigue at the last visit (8253.7 +/- 10317.3 units/wk vs 4736.4 +/- 5432.5, p < 0.03). No correlation was found between dialysis adequacy according to either weekly Kt/V or TCrCl and nutritional state according to nPCR and frequency of fatigue. We conclude that fatigue is a common symptom in PD patients and it's prevalence increases over time. Anemia seems to be the most important factor associated with fatigue. Dialysis adequacy and nutritional state did not show any correlation with the frequency of fatigue in our study.

Adult↗
PubMed2003

Glucose and mannitol have different effects on peritoneal morphology in chronically dialyzed rats.

In previous studies, we showed that glucose reduces the morphologic changes in rat peritoneum caused by chronic intraperitoneal administration of 0.9% NaCl solution. In the present study, we set out to determine if the observed results were attributable to hyperosmolarity or to the metabolic effect of the glucose. Intraperitoneal catheters were implanted in 19 rats. The animals were then intraperitoneally exposed twice daily for 30 days to 20 mL 0.9% saline supplemented with either 250 mmol/L glucose (GLU, n = 9) or 250 mmol/L mannitol (MAN, n = 10). Control rats did not undergo catheter implantation or the dialysis procedure (CON, n = 6). At the end of the study, a 1-hour peritoneal equilibration test (PET) using Dianeal 3.86% (Baxter Healthcare SA, Castlebar, Ireland) was performed in every dialyzed rat to analyze peritoneal transport. Afterward, the rats were humanely killed by bleeding, and a semi-quantitative scale was used to evaluate adhesions in the peritoneal cavity. Imprints of the visceral mesothelium and samples of the visceral peritoneum (liver) were then taken and analyzed by light microscopy. The PET results for glucose, urea, creatinine, and total protein were comparable in both experimental groups. We found that intraperitoneal adhesions were more severe in the MAN group (6 rats with adhesions graded > 3) than in the GLU group (only 1 such rat). No difference in peritoneal thickness was observed between the experimental groups (MAN: 54.9 +/- 17.8 microns; GLU: 51.2 +/- 14.5 microns); however, in both experimental groups, the thickness was greater than in the CON group (3.9 +/- 0.6 microns). The density of the peritoneal blood vessels tended to be greater in the MAN group than in the GLU group (0.158 +/- 0.072 vessels/1000 microns 2 vs. 0.085 +/- 0.067 vessels/1000 microns 2, p = 0.0541). No visible blood vessels were evident in the CON group. The density of mesothelial cells was higher in the MAN group than in the GLU group (2456 +/- 333 cells/mm 2 vs. 2090 +/- 322 cells/mm 2, p < 0.05), and, in both experimental groups, the cell density was higher than in the CON group (817 +/- 100 cells/mm 2, p < 0.01). The nucleus: cytoplasm area ratio in mesothelial cells was comparable in the MAN and GLU groups (0.206 +/- 0.039 and 0.176 +/- 0.045), but that ratio was higher in both experimental groups than in the CON group (0.086 +/- 0.010, p < 0.01). We conclude that glucose-induced changes in the peritoneum of rats exposed to chronic peritoneal dialysis depend on both osmotic and metabolic effects.

Animals↗
PubMed2003

Morphologic changes in the liver of dialyzed rats--preliminary observations.

Peritoneal dialysis affects both the quantity and quality of connective tissue in the visceral peritoneum. In the present study, we report the alterations observed in the morphology of the superficial liver lobuli of dialyzed rats. The studies were performed in male Wistar rats weighing 250-350 g. Rats were exposed intraperitoneally to 0.9% NaCl, phosphate-buffered saline (PBS), or commercial dialysis solutions containing 3.86% glucose (Dianeal 3.86%: Baxter Healthcare SA, Castlebar, Ireland; CAPD3 and CAPD3-Balance: Fresenius Medical Care, Bad Homburg, Germany) twice daily for 4-6 weeks. At the end of the study, samples of the liver were taken and stained for light microscopy (hematoxylin and eosin, van Gieson). The results obtained in dialyzed rats were compared with those from the control, non dialyzed animals. In control animals, the surface of the hepatic parenchyma was smooth. In all dialyzed rats, irrespective of the solution used, folding of the surface of the liver parenchyma was found owing to penetration of connective tissue elements between the hepatocytes. In effect, folds of hepatocytes within the liver capsule became detached and isolated from the remaining cells of the lobules. The distinctive feature of that pathologic change was that its severity increased with the thickness of the peritoneum. The change was seen in rats exposed to any of the experimental solutions, and therefore appeared to be attributable to a non-specific reaction caused by exposure of the peritoneum to dialysis fluid and not to specific components of the fluid. The observed alterations in morphology seem to suggest disturbed function within the affected lobules. Further studies are necessary to confirm this hypothesis.

Animals↗
PubMed2002

Renal stone disease, elevated iPTH level and normocalcemia.

BACKGROUND: There is a well established relationship between primary hyperparathyroidism and recurrent calcium-containing calculi. Traditionally, the diagnosis is confirmed by the presence of elevated intact parathyroid hormone (iPTH) and serum ionised calcium levels. The prevalence and role of elevated iPTH in the presence of normocalcemia in patients with renal stone disease is poorly understood. The aim of the present study was to describe the findings in patients who had renal stone disease, an elevated iPTH level and normocalcemia. METHODS: During the last decade, 414 patients, who had normal renal function, were investigated and treated for renal calculi in the Renal Stone Clinic of the Toronto Western Hospital. Of these 414 patients, 40 (9.6%) had an elevated intact iPTH level and normal serum calcium (total and ionised) on repeated measurements. In all these patients we performed detailed clinical and laboratory investigations to determine risk factors for stone formation. Correlation analysis was done using Pearson test and the weights of factors influencing iPTH level were compared using multiple regression analysis. RESULTS: The average duration of a history of stone disease was 12.0 +/- 10.5 years. Most of these patients had passed their stones spontaneously, 15 underwent lithotripsy, in six the stones were removed by basket catheters and one patient each had partial nephrectomy, nepholithotomy or uretero-lithotomy. Twelve had a positive family history, two had history of intestinal malabsorption and one patients had a history of immobilisation. All of these patients had elevated serum parathyroid hormone in the range of 3% to 134% (median 20.5%) above upper limit of normal (F = M); all had normal serum total and ionised calcium and normal urine excretion of calcium (except in one). Additional risk factor for stone formation included: low level of 25-hydroxyvitamin D in four patients, low output and high urine osmolality in four patients, high urine sodium in nine and high oxalate excretion in eight patients. Citrate excretion was low in seven, magnesium excretion in six patients and tubular reabsorption of phosphate in 22 patients. Urine hydroxyprolin was increased in two and decreased in four patients. Combined abnormalities were found in 14 while 17 patients did not have any abnormality apart from elevated iPTH level. Multiple regression analysis did not suggest that any of the selected predictors had a significant influence on PTH release. CONCLUSIONS: 9.6% of patients with recurrent kidney stones had normocalcemia and elevated iPTH level in the presence of normal renal function. The study did not show any distinct pattern of abnormalities that would suggest a mechanism of stone disease in these patients. Further investigations are necessary to determine the significance of elevated iPTH in normocalcemic patients with renal stone disease and establish whether we should consider neck exploration for parathyroidectomy in these patients.

Adolescent↗
PubMed2002

Beyond Kt/V: redefining adequacy of dialysis in the 21st century.

I presume that every dialysis patient needs a minimal amount of dialysis, since less dialysis will lead to death. Until we come up with a better index, for hemodialysis, I propose that we should return to Scribner's 1974 recommendation on adequacy of dialysis and concentrate on the homeostatic function of the kidney, as indicated in Table 1. For those who still want to measure dialysis dose by Kt/V, the optimal dose for HD is a Kt/V of 1.2/treatment and for PD 1.7/week. None of these would be adequate without good UF and control of patients' fluid status. Frequent (4, 5, 6 or 7 days/week) and prolonged dialyses (5-8 hours) should be the norm and I believe that the Hemodialysis Product should be used as a guide, pending confirmation by prospective studies. A high hemodialysis product reflects much more closely the function of the normal kidneys than 3-4 hours of dialysis three times a week with a Kt/V of 1.2 per session. Peritoneal dialysis that is already continuous needs to improve its efficiency. For PD patients, I believe that the total daily volume (Kt) might be a better index of adequacy, especially if it is combined with a good ultrafiltration (at least of 1 L/day) and blood pressure control. Of course, this has to be confirmed in the future. In the anuric patients, the daily volume can be kept to 8 L/day if the patient is free of symptoms, but should be increased to 10-12 L/day for CAPD and 15-20 L/day for APD patients if they develop symptoms of underdialysis and fluid overload.

Blood Urea Nitrogen↗
PubMed2002

Glucose suppresses peritoneal inflammatory reactions and mesothelial hyperplasia caused by intraperitoneal saline infusion.

In the past, we had observed that infusion of normal saline into the peritoneal cavity stimulates an inflammatory response. In the present study, we examined what effect the addition of glucose to normal saline would have on the peritoneal inflammatory response and change in peritoneal morphology. After catheter implantation, rats were infused intraperitoneally (i.p.) for 3 days with Dianeal 1.36% (Baxter Healthcare Corporation, Deerfield, IL, U.S.A.). Dialysate samples were collected on day 3 after a 4-hour dwell. Next, rats were exposed to either NaCl (n = 7) or NaCl with glucose 250 mmol/L (Glu, n = 7) twice daily for 4 weeks. After 2 weeks and 4 weeks of the study, dialysate samples were collected after a 4-hour dwell to analyze the activity of inflammatory reaction. At the end of the experiment, imprints of peritoneal mesothelium were taken. Control animals (C, n = 6) did not undergo catheter implantation or the dialysis procedure. The inflammatory reaction--cell count, cell differentiation, nitric oxide production, protein loss, and monocyte chemoattractant protein-1 (MCP-1) concentration in dialysate expressed as a percentage of the initial value--did not change during the study in rats exposed to NaCl. On the other hand, in Glu-treated animals, the protein concentration was decreased after 4 weeks of the study (74% +/- 23%, p < 0.05), as was MCP-1 (24% +/- 12%, p < 0.05). The nitrites concentration was decreased after 2 weeks (72% +/- 19%; p < 0.05). Intraperitoneal adhesions were found in 6 rats of the NaCl group (86%) and in only 4 rats (57%) of Glu group. In the NaCl rats, a higher density of mesothelial cells was observed (2792 +/- 510 cells/mm2) as compared with Glu rats (2028 +/- 561 cells/mm2; p < 0.05) and with control rats (1629 +/- 422 cells/mm2, p < 0.05). The NaCl group also showed a higher nucleus: cytoplasm surface ratio (0.25 +/- 0.03) as compared with the Glu group (0.18 +/- 0.02, p < 0.01) and with the control group (0.14 +/- 0.01, p < 0.01). Addition of glucose to normal saline suppresses the peritoneal inflammatory response and mesothelial hyperplasia occurring with intraperitoneal infusion of NaCl solution alone.

Animals↗
PubMedDate not supplied

Chronic peritoneal dialysis in the elderly.

Available data indicate that peritoneal dialysis (PD) offers some advantages for the increasing number of elderly patients with ESRD, such as hemodynamic stability, steady-state metabolic control, good control of hypertension, independence from hospital visits, and avoidance of repeated vascular access. Early referral promotes the establishment of peritoneal access and minimizes the consequences of uremia and subsequent morbidity and frequent hospitalization. Elderly patients have similar modality-related complications such as peritonitis, catheter-related complications, exit-site and tunnel infection, and hernias as younger patients. Comorbid conditions, malnutrition, and psychosocial status influence the survival of elderly patients on PD. Elderly patients are compliant and highly motivated to cooperate in treatment. They are more tolerant of changes and losses and have a greater sense of well-being, less illness and modality-related stress, and fewer mood disturbances. Despite comorbid conditions, that significantly impair self-performance of dialysis, PD can be performed successfully if they have family support or access to a network of medical and social support, that is, home nurses, rehabilitation services, and chronic care dialysis units, or nursing homes.

Aged↗
PubMedDate not supplied

Colonization-resistant antimicrobial-coated peritoneal dialysis catheters: evaluation in a newly developed rat model of persistent Pseudomonas aeruginosa peritonitis.

OBJECTIVE: Development of a rat model of persistent peritonitis and evaluation of the ability of liposomal ciprofloxacin hydrogel-coated silicone to resist colonization. DESIGN: A newly developed model of persistent Pseudomonas aeruginosa peritonitis to compare the ability of liposomal ciprofloxacin hydrogel (LCH)-coated silicone versus plain silicone for resistance to bacterial colonization. ANIMALS: Male Sprague-Dawley rats. RESULTS: Inoculating the peritoneum of rats with 1 mL 0.5% agar containing 10(6) colony-forming units (cfu)/mL P. aeruginosa in the presence of a plain silicone coupon resulted in persistent peritonitis for at least 7 days. Plain silicone coupons in all 40 rats were colonized (median 2.54 x 10(3) cfu/cm2; range 5.0 x 10(1)-1.0 x 10(6) cfu/cm2) and peritoneal washings were consistently culture-positive. In contrast, the LCH coupons removed after 7 days from the 40 test rats were sterile, as were the peritoneal washings, and there was no evidence of peritonitis. Blood cultures were negative in both groups. CONCLUSIONS: Liposomal ciprofloxacin hydrogel-coated silicone resists colonization in this rat model of persistent P. aeruginosa peritonitis.

Animals↗
PubMedDate not supplied

Normal or low initial PTH levels are not a predictor of morbidity/mortality in patients undergoing chronic peritoneal dialysis.

OBJECTIVE: During the past few decades, the pattern of bone disease in uremic patients has changed significantly. There has been an increase in the number of patients with normal or low initial parathyroid hormone (PTH) levels, particularly in patients on chronic peritoneal dialysis (CPD). Previous authors have described a higher prevalence of bone pain, microfractures, and fractures, and higher mortality among these patients. The aim of this study was to determine the incidence, morbidity, and mortality of patients who had a low or normal intact PTH (iPTH) level when they started CPD. DESIGN: We reviewed the records of 251 patients in our program that started CPD during the past 5 years (January 1996-December 2000). Clinical data, laboratory variables, medication, and dialysis parameters/dose were available at every clinic visit (approximately every 4 weeks). Intact PTH was used to express parathyroid function; values 3 times higher than the upper limit of normal (ULN) were assumed to be optimal. Variables predictive of the development of parathyroid dysfunction were calculated by univariate and multivariate logistic regression analysis. RESULTS: Of the patients who started CPD, 15.5% had iPTH values below the ULN (7.6 pmol/L), and an additional 29.5% had an iPTH of less than 3 times the ULN (i.e., between 7.6 and 22.8 pmol/L). We call these two groups of patients the normal/low initial iPTH group. During the follow-up period (3-63 months), we found a trend toward increasing iPTH levels. By the end of the study period, 61.2% of those with normal/low initial iPTH remained in the normal/low iPTH range, and 38.8% had converted to a group with an iPTH range higher than 22.8 pmol/L. The patients who converted their iPTH grouping were younger, fewer of them were diabetics (p = not significant), and they were more frequently on low calcium dialysate (p < 0.05). Hyperphosphatemia was an independent risk factor for subsequent iPTH changes during the course of continuous ambulatory PD treatment. All patients in the normal/low iPTH groups had a low prevalence of bone fractures (3.5%). Also, patients who remained in the normal/low iPTH group at the end of the follow-up period did not have more fractures than those who converted to the hyperparathyroid group (3.8% vs 3.1%). We found no differences in bone fractures between patients with iPTH levels below 22.8 and those with levels above 22.8 pmol/L (3.5% vs 5.4%), nor were there differences in patient and technique survival between these two groups. CONCLUSION: Normal/low initial iPTH is a frequent finding among patients starting CPD. Serum phosphorus was an independent risk factor for subsequent iPTH changes during the course of CPD treatment. Use of low calcium dialysate was significantly higher in patients who converted their iPTH into the high iPTH range. Very few patients with low/normal iPTH had bone-related symptoms (pain and fractures), and their morbidity and mortality did not differ from those patients with a high initial iPTH level.

Blood Urea Nitrogen↗
PubMedDate not supplied

L-2-oxothiazolidine-4-carboxylate: an agent that modulates lipopolysaccharide-induced peritonitis in rats.

OBJECTIVE: L-2-Oxothiazolidine-4-carboxylate (OTZ), a cysteine precursor, is a substrate for intracellular glutathione synthesis. As shown previously, OTZ prevents free-radical induced cellular damage during in vitro simulation of peritoneal dialysis. In the present study, we examined the effect of adding OTZ to peritoneal dialysis solution on peritoneal function and structure during lipopolysaccharide (LPS)-induced peritonitis in rats. In addition, we studied the effects of pretreatment with OTZ (given orally) on the effects of LPS-induced peritonitis in rats. METHODS: Peritonitis was induced in rats by adding LPS (5 microg/mL) to the dialysis fluid. For acute experiments, rats were exposed to a single infusion of dialysis solution containing LPS or to LPS plus 5 mmol/L OTZ; peritoneal cell counts and permeability were determined after 4 hours. Alternatively, rats were pretreated with OTZ added to the drinking water (0.1%) for 10 days prior to infusion of LPS. For chronic experiments, peritoneal dialysis was performed over a 3-week period in rats with implanted peritoneal catheters. On days 8, 9, and 10 of the experiment, the rats were infused intraperitoneally with solution containing LPS (5 micro/mL), or LPS plus 5 mmol/L OTZ, to induce acute peritonitis. At the end of dialysis (10 days after the episodes of peritonitis), peritoneal function was assessed using a peritoneal equilibration test (PET), and peritoneal biopsies were taken to assess effects on peritoneal morphology. RESULTS: In the acute experiments, exposure to LPS led to increased peritoneal cell counts (+61% vs control, p < 0.05) and enhanced permeability of the peritoneum, leading to a loss in ultrafiltration (-63%, p < 0.0005). The glutathione concentration in peritoneal leukocytes also decreased during acute peritonitis (-31%, p < 0.05). During LPS-induced peritonitis, OTZ prevented the increase in dialysate cell count and the decrease in cellular glutathione content. Simultaneous administration of OTZ did not prevent the increased peritoneal permeability induced by LPS. However, in rats pretreated with OTZ, LPS-induced permeability to protein was significantly lower than in the nontreated animals (0.049 +/- 0.011 vs 0.087 +/- 0.034, p < 0.05). In the chronic experiments, LPS-induced peritonitis did not lead to any functional differences in peritoneal transport at the end of 3 weeks of dialysis. However, LPS-induced peritonitis led to increased thickness of the peritoneum and neovascularization within peritoneal interstitium compared to peritonitis-free animals. In contrast to the LPS-treated animals, the peritoneum of the rats exposed to LPS in the presence of OTZ was of a thickness similar to that in the control rats. CONCLUSION: Supplementation of dialysis fluid with OTZ prevented changes in cellular glutathione levels and dialysate cell counts during acute peritonitis in rats. During chronic dialysis in rats exposed to intermittent peritonitis episodes, OTZ prevented increased thickening and neovascularization of the peritoneum. Our results suggest this may help to protect the peritoneal membrane during episodes of peritonitis.

Administration, Oral↗
PubMedDate not supplied

Predictors of outcome following bacterial peritonitis in peritoneal dialysis.

OBJECTIVE: No studies have been done to examine factors that predict the outcome of bacterial peritonitis during peritoneal dialysis (PD), beyond the contribution of the organism causing the peritonitis, concurrent exit-site or tunnel infection, and abdominal catastrophes. DESIGN: In this study we examined several clinical and laboratory parameters that might predict the outcome of an episode of bacterial peritonitis. Between March 1995 and July 2000, we identified 399 episodes of bacterial peritonitis in 191 patients on dialysis. RESULTS: There were 260 episodes of gram-positive peritonitis, 99 episodes of gram-negative peritonitis, and 40 episodes of polymicrobial peritonitis. Gram-positive peritonitis had a significantly higher resolution rate than either polymicrobial peritonitis or gram-negative peritonitis. Staphylococcus aureus episodes had poorer resolution than other gram-positive infections. Nonpseudomonal peritonitis had a better outcome than Pseudomonas aeruginosa episodes. Among all the gram-negative infections, Serratia marcescens had the worst outcome. Episodes associated with a purulent exit site had poor outcome only on univariate analysis. For those peritonitis episodes in which the PD fluid cell count was > 100/microL for more than 5 days, the nonresolution rate was 45.6%, compared to a 4.2% nonresolution rate when the cell count returned to 100/microL or less in less than 5 days. Those patients that had a successful outcome had been on continuous ambulatory PD for a significantly shorter period of time than those patients that had nonresolution. The nonresolution rate for those patients that had been on PD for more than 2.4 years was 24.4%, compared to 16.5% for those that had been on PD for less than 2.4 years (p = 0.05). CONCLUSION: The duration of PD and the number of days the PD effluent cell count remained > 100/microL were the only factors that independently predicted the outcome of an episode of peritonitis. Caucasians seem to have a higher nonresolution (failure) rate compared to Blacks. Other variables, such as the number of peritonitis episodes before the episode in question, vancomycin-based initial empiric treatment, serum albumin level, total lymphocyte count and initial dialysate white blood cell count, age, sex, diabetes, previous renal transplantation, and the use of steroids did not affect the outcome of peritonitis.

Adult↗