The assessment of stress level, anxiety, depressive symptoms, and defense mechanisms among Polish and English medical students.

INTRODUCTION: Medical education is proven to be associated with a high degree of psychological stress. Different coping strategies used by students have been investigated on their efficacy. So far, studies on medical students have been limited to a single population. AIM OF THE STUDY: Our study aimed to identify differences in the prevalence of depressive symptoms, anxiety, stress levels, and defense mechanisms among two groups of medical students, the Polish and English-speaking divisions. MATERIALS AND METHODS: The study included two groups of first-year medical students, the Polish and English-speaking divisions, comprising 305 participants (n = 204 Polish, n = 101 English, men = 127, women = 176). It was divided into two periods: the students received author questionnaires during an exam-free academic period and then completed the same questionnaires during an exam session. The survey contained questions pertaining to demographics and studying habits among participants and included the Defense Style Questionnaire and Depression Anxiety Stress Scales. Data were analyzed using STATISTICA version 12.0, and p ≤ 0.05 was considered significant. RESULTS: Polish medical students presented with significantly increased overall stress levels (p = 0.007858) and depressive symptoms (p = 0.030420) compared to the English division students. Polish students also presented with more symptoms of stress, depression, and anxiety during the exam period compared to the exam-free period (p = 0.000625), which did not apply to the English-speaking students. The English division students reached higher scores in the mature defense mechanisms section than the Polish students (p = 0.000001). The use of mature defense mechanisms correlated negatively with the intensity of stress, anxiety, and depressive symptoms in both groups, while immature defense mechanisms promoted higher values of those variables (p = 0.000001). CONCLUSIONS: Our study showed significant and multidirectional differences between medical students of the Polish and English divisions attending the same university. Such results could suggest that strategies aimed at reducing depressive symptoms among medical students ought to be adapted towards the needs of a specific population.

Space-based estimation of the solar UV-B doses for psoriasis heliotherapy in Poland using OMI data for the period 2005-2011.

A UV model is proposed to reconstruct the biologically weighted doses at the ground-level, erythemal, vitamin D(3), and antipsoriatic effective doses, based on the space data from the Ozone Monitoring Instrument on board of NASA EOS Aura spacecraft for the period 2005-2011. The model is training using the results of spectral UV measurements carried out at Belsk, Poland. The model outcome is verified using the UV spectra measured at Hradec Kralove, Czech Republic. The model uncertainty is almost the same for all examined action spectra and comparable to that found in earlier studies on differences between the satellite overpasses and ground-based erythemal data. Antipsoriatic doses, taken during 2h exposure periods near local noon, are reconstructed for selected sites in Poland to find if heliotherapy would be an alternative to standard treatment of psoriasis by tube irradiation in medical cabinets. Mountain-resort in the southern Poland, Zakopane, and rural-site in Central Poland, Belsk, are among the best location of potential heliotherapy centers in Poland for late spring/summer season. Leba, resort on the Baltic Sea coast, is a potential heliotherapy center in June and July. The methodology to disclose possible heliotherapy periods over the territory of Poland could be extended to any region. It would help to prepare an optimal schedule of antipsoriatic heliotherapy that accounts for local weather conditions and medical standards of using UV cabinets.

Effectiveness of heliotherapy for psoriasis clearance in low and mid-latitudinal regions: a theoretical approach.

The action spectrum for psoriasis clearance is reconstructed taking into account the results obtained in the early 1980s. The antipsoriatic action spectrum is used for weighting the medical cabinet UV spectra, and the solar spectra measured in San Diego (USA) and Belsk (Poland). The mean cumulative antipsoriatic effective dose of 450 mJ cm(-2), due to TL-01 (UVB narrowband) tubes, is taken by a patient with skin phototype II during routine 20 phototherapy sessions carried out in a phototherapy cabinet in the Medical University of Lódz. Thus, the daily mean dose of value 22.5 mJ cm(-2) is proposed as the threshold for daily solar dose for numbers of out-door exposures to clear psoriasis. We assume that the heliotherapy will last a whole month with every day 2h exposition to the direct sunlight around local noon. The heliotherapy will be successful if weather conditions permit at least 20 days with the daily exposure over the threshold. The minimum cumulative ambient erythemal dose, necessary for psoriasis clearance, is estimated as 144 standard erythema dose (SED) for the whole heliotherapy period. We find that heliotherapy could be effectively used in March through October (San Diego) and in June through August (Belsk). Thus, the heliotherapy against psoriasis is possible not only at southern resorts but even at the mid-latitude sites.

No evidence of HTLV-I infection in patients with mycosis fungoides and Sezary syndrome.

The involvement of human T-cell lymphotropic virus type I (HTLV-I) in the etiology of cutaneous T-cell lymphomas (CTCL) is still controversial. The aim of the study was to evaluate the role of HTLV-I in the pathogenesis of mycosis fungoides (MF) and Sezary syndrome (SS) in Polish patients. The studied group consisted of 42 patients with MF, 5 with SS and 25 with chronic dermatitis. DNA was extracted from snap-frozen and paraffin-embedded skin biopsies and from peripheral blood. Polymerase chain reaction (PCR or nested PCR) was carried out for amplification of different regions of HTLV-I genome. Primer sets flanking pX, p 19, U5, tax and pol genes were used in the investigation. The presence of HTLV-I antibody was examined in 46 sera samples with the use of anti-HTLV-I/II EIA test. HTLV-I antibodies were not detected in any collected sera samples. PCR with two primer sets homologous to the pX region of HTLV-I showed negative results in all samples investigated. To confirm these results two other primer pairs specific for U5 and gag regions were designed. With these primer pairs no PCR product, except that in positive control, was observed. For more sensitive amplification a nested-PCR with pol and tax specific primers was performed. HTLV-I probably does not play an important role in the pathogenesis of MF in Polish patients.

Thermoluminescent dosimetry in rotary-dual technique of the total skin electron irradiation.

The aim of the study was to discuss the results of thermoluminescent dosimetry (TLD) in rotary-dual technique of the total skin electron irradiation (TSEI RD), to confirm beam calibration and monitor unit calculations and to provide data for making clinical decisions. Between May 2001 and April 2002, in 3 cases of mycosis fungoides, 736 dosimetric checks were performed in 34 points at the skin. CaF2:MnTLD-400 cubes (1/8"x1/8"x0.015") were used for in vivo dosimetry. Doses were computed and analyzed for all locations. Percent of described dose and SD for the following localizations from 34 points were: anterior abdomen (reference point) 100+/-6%, upper back 100+/-8%, right calf 98+/-10%, left foot (mid dorsum) 97+/-8%, posterior neck 93+/-6%, right hand (mid dorsum) 78+/-10%, hand fingers 57+/-10%, top of right shoulder 56+/-14%, left groin 35+/-20%, perineum 22+/-17%. The correlations between patient's height and measured doses were sufficient for the following localizations: scalp (top rear), occiput, elbows, hand fingers and hands (mid dorsum). The correlations between obesity index and measured doses were sufficient for the following localizations: shoulders and lateral neck, groins, and perineum. Dosimetric checks at the reference point confirm that our beam calibration technique and monitor unit calculation are accurate. TLD shows that for some parts of the skin such as shoulder, hands and perineum boost fields were required. The correlations with obesity index and height for several sites suggest that boost fields must be customized for each patient.

[Regular menstrual bleeding in a woman after hysterectomy]. / Regularne krwawienia miesiaczkowe u kobiety po wycieciu macicy.

The authors present a rare case of 39 years old woman, who had regular monthly bleedings mimicking menstruation during the two years after abdominal hysterectomy (without the adnexa). The woman was operated on in 1997 because of large uterine myoma and presented no other pathology in the abdominal cavity. She also suffered from autoimmunological anemia and chorea, which decreased her life activity and resulted in lack of gynecological care after the operation. The patient misunderstood the effect of surgery and mistook bleedings for signs of normal hormonal function. Deep external endometriosis of vaginal cuff and surrounding tissues was the cause of 'menstruation'. All this tissues were surgically removed. An immunological mechanism which plays role in endometriosis, chorea and anemia, was discussed.

Intraperitoneal hyaluronan administration in conscious rats: absorption, metabolism, and effects on peritoneal fluid dynamics.

BACKGROUND: Hyaluronan (HA) is a major component of interstitial tissue that participates in fluid homeostasis, response to inflammation, and wound healing. Previous studies have shown that intraperitoneal administration of HA can affect peritoneal fluid transport during short peritoneal dialysis exchanges in anesthetized rats. We sought to investigate the effect of high molecular weight HA on peritoneal permeability in conscious rats during dialysis exchanges up to 8 hours in duration. In addition, we sought to investigate the absorption of HA from the peritoneal cavity, its accumulation in peritoneal tissues, and its metabolism in normal and uremic rats. METHODS: Experiments were performed on male Wistar rats infused with 30 mL peritoneal dialysis solution (Dianeal, Baxter Healthcare; Castelbar, Ireland) containing 10 mg/dL HA or with Dianeal alone (control). Peritoneal fluid removal (net ultrafiltration), permeability to glucose, creatinine, and total proteins, and tissue and blood levels of HA were determined in separate groups of rats at 1,2, 4, 6, and 8 hours after intraperitoneal infusion. Hyaluronan appearance and disappearance from plasma were also studied for 24 hours in separate groups of normal and uremic rats. RESULTS: Net ultrafiltration was significantly greater (27%) in rats infused with HA at 4, 6, and 8 hours (p < 0.01) compared to controls. Transperitoneal equilibration of protein was reduced by 27% (p < 0.001) at 4 hours and by 30% (p < 0.01) at 8 hours. During the 8-hour exchange, peritoneal clearance of creatinine increased by 27% (p < 0.01), whereas the clearance of total protein decreased by 27% (p < 0.005). After 8 hours, 25.7% +/- 3.1% of the administered HA was absorbed from the peritoneal cavity, peritoneal tissue HA concentration was increased by 117% (p < 0.001), and plasma HA levels increased by 435% (p < 0.001). Plasma HA levels returned to normal within 24 hours after intraperitoneal administration in both healthy and uremic rats. CONCLUSIONS: Hyaluronan added to dialysis fluid is absorbed from the peritoneal cavity and accumulates in peritoneal tissues. Hyaluronan supplementation produces changes in peritoneal permeability, leading to higher net ultrafiltration and peritoneal creatinine clearance, whereas total protein clearance decreases. The HA that is absorbed from the peritoneal cavity appears to be rapidly metabolized in both healthy and uremic rats.

Multidirectional approach to study peritoneal dialysis fluid biocompatibility in a chronic peritoneal dialysis model in the rat.

BACKGROUND: Peritoneal dialysis causes the functional and morphological changes in the peritoneum that result from the bioincompatibility of dialysis solutions. We present a model of chronic peritoneal dialysis in the rat that can be used for testing the biocompatibility of dialysis fluids. Methods and Results. Long-term exposure of the peritoneum to dialysis solutions can be performed in rats with implanted peritoneal catheters. Sampling of the dialysate allows the evaluation of intraperitoneal inflammation by examining cell differential and dialysate cytokine levels. Peritoneal permeability can be evaluated at designed time intervals with the peritoneal equilibration test (PET). At the end of dialysis, peritoneal histology is studied with light and electron microscopy. CONCLUSIONS: Such a multidirectional approach is an effective way to test biocompatibility of dialysis solutions.

Effects of intraperitoneal heparin on peritoneal transport in a chronic animal model of peritoneal dialysis.

BACKGROUND: Heparin has anti-inflammatory effects and is often added to the peritoneal dialysis fluid to prevent fibrin formation. Conjugation of heparin to the surface of biomaterials has been shown to improve its biocompatibility. In this study, we describe for the first time an experimental chronic peritoneal dialysis model with repeated dwell studies in non-uraemic rats and evaluate the effect of addition of heparin to glucose-based peritoneal dialysis fluid on peritoneal fluid and solute transport. METHODS: Wistar male rats, weighing 340+/-15 g, with implanted peritoneal catheters were infused during 1 month, twice per day with 20 ml of Dianeal 1.36%+antibiotics (AB; n = 10) or Dianeal 1.36%+antibiotics+heparin 2500 U/l (HAB; n = 9). After 10 (DS 1) and 30 days (DS 2), a dwell study was performed in rats with free access to drinking water, by infusing 30 ml of Dianeal 3.86%. Dialysate samples were obtained at 0, 2, 30, 60, 120 and 240 min. Blood samples were drawn before and at the end of the dwell. Radiolabelled serum albumin was used as macromolecular volume marker. RESULTS: Peritoneal volumes during DS 1 were significantly greater for the HAB group as compared with the AB group. No differences in ultrafiltration were found during DS 2 for HAB vs AB. However, peritoneal volumes were significantly higher for DS 2 compared with DS 1 in the AB group. The amount of glucose absorbed over time did not differ between the solutions, while fluid absorption tended to be lower in the HAB group. CONCLUSIONS: Heparin may improve peritoneal fluid transport possibly due to better healing and reduced peritoneal inflammation as shown in this novel animal model of chronic peritoneal dialysis with repeated dwell studies.

The effect of icodextrin-based solutions on peritoneal transport in rats undergoing chronic peritoneal dialysis.

BACKGROUND: We evaluated the effect of icodextrin on peritoneal permeability and inflammation in an experimental chronic peritoneal dialysis (PD) model with repeated dwell studies (DSs) in non uremic rats. METHODS: Male Wistar rats with implanted peritoneal catheters were infused twice daily for 3 weeks with 20 mL Dianeal 3.86% (Baxter Healthcare Corporation, Deerfield, IL, U.S.A.) (n = 11) or icodextrin 7.5% (n = 12). After 10 days (DS1) and 21 days (DS2), a 4-hour DS using 30 mL icodextrin solution was performed in conscious animals. Radioiodinated serum albumin (RISA) was used as a macromolecular volume marker. Blood samples were drawn before the start of the dwell and at its end. RESULTS: We observed a steady increase in intraperitoneal volume (IPV) versus dwell time (0-240 minutes) during DS1 and DS2 in both groups. No significant differences in peritoneal permeability to solutes were observed between the groups. However, in both groups, IPV volume was significantly higher during DS2 after the 4-hour dwell time [IPV icodextrin: 34.4 +/- 1.4 mL (DS1), 35.4 +/- 1.1 mL (DS2), p < 0.002; IPV Dianeal: 34.2 +/- 0.9 mL (DS1), 35.2 +/- 0.7 mL (DS2), p < 0.01]. CONCLUSION: Changes of peritoneal permeability seen during in vivo experimental models of chronic peritoneal dialysis in rats with repeated dwell studies are comparable to results obtained in humans on continuous ambulatory peritoneal dialysis (CAPD).

Prevalence of bacterial vaginosis in adolescent girls.

The age-related increase in the prevalence of bacterial vaginosis was determined in adolescent virginal and sexually active girls aged 13 to 18 years. Higher rates were recorded for girls with two or more sexual partners. Considering the potential spectrum of consequences of bacterial vaginosis, preventive strategies are required in this age group, not only for bacterial vaginosis but also for other sexually transmitted diseases.

IL-17 stimulates intraperitoneal neutrophil infiltration through the release of GRO alpha chemokine from mesothelial cells.

IL-17 is a newly discovered cytokine implicated in the regulation of hemopoiesis and inflammation. Because IL-17 production is restricted to activated T lymphocytes, the effects exerted by IL-17 may help one to understand the contribution of T cells to the inflammatory response. We investigated the role of IL-17 in leukocyte recruitment into the peritoneal cavity. Leukocyte infiltration in vivo was assessed in BALB/Cj mice. Effects of IL-17 on chemokine generation in vitro were examined in human peritoneal mesothelial cells (HPMC). Administration of IL-17 i.p. resulted in a selective recruitment of neutrophils into the peritoneum and increased levels of KC chemokine (murine homologue of human growth-related oncogene alpha (GROalpha). Pretreatment with anti-KC Ab significantly reduced the IL-17-driven neutrophil accumulation. Primary cultures of HPMC expressed IL-17 receptor mRNA. Exposure of HPMC to IL-17 led to a dose- and time-dependent induction of GROalpha mRNA and protein. Combination of IL-17 together with TNF-alpha resulted in an increased stability of GROalpha mRNA and synergistic release of GROalpha protein. Anti-IL-17 Ab blocked the effects of IL-17 in vitro and in vivo. IL-17 is capable of selectively recruiting neutrophils into the peritoneal cavity via the release of neutrophil-specific chemokines from the peritoneal mesothelium.

Dialysis solution containing hyaluronan: effect on peritoneal permeability and inflammation in rats.

BACKGROUND: Hyaluronan (HA), a high molecular weight mucopolysaccharide found in interstitial tissues and fluid, is lost from the peritoneal cavity during peritoneal dialysis. In order to determine the role of HA in peritoneal function, we investigated the effects of exogenous HA on peritoneal permeability, markers of intraperitoneal inflammation, and peritoneal morphology in rats exposed to peritoneal dialysis solution for four weeks. METHODS: Wistar rats were infused intraperitoneally, twice daily, with conventional, hypertonic dialysis solution (Dianeal 3.86%; control) or Dianeal solution containing 10 mg/dL of high molecular weight HA. Peritoneal permeabilities and clearances of solutes and protein were determined using a modified peritoneal permeability test (peritoneal equilibration test) at the beginning and the end of the treatment. Peritoneal volume and ultrafiltration were determined using a macromolecular marker and by gravimetric methods. Peritoneal inflammation was determined by cell counts and differential and by the measurement of cytokine concentrations in the dialysate effluent. Peritoneal thickness and HA content were determined in liver and mesentery biopsies taken at the end of the experiment. RESULTS: After four weeks of exposure to the dialysis solution, transperitoneal protein equilibration was significantly lower in HA-treated rats compared with rats treated with Dianeal alone (46% lower for albumin, P < 0.003; 33% lower for total protein, P < 0.001). The total drained volume after a four hour dwell was 29% higher in the HA group compared with the control (P < 0.001), yielding a positive net ultrafiltration in the HA group versus a negative net ultrafiltration in controls. Peritoneal clearances of urea and creatinine tended to be elevated in HA-treated rats, while clearances of total protein and albumin tended to be lower. Dialysate effluent from rats exposed to HA contained a lower percentage of neutrophils (8.8 +/- 22.8 +/- 9.5%, P < 0.01) and lower levels of the cytokines, tumor necrosis factor-alpha (11.2 +/- 14.7 vs. 42.3 +/- 35.3 pg/mL, P < 0.05) and monocyte chemoattractant protein-1 MCP-1 (72.0 +/- 86.5 vs. 402.4 +/- 258.3 pg/mL, P < 0.02), compared with rats treated with Dianeal alone. The thickness of the peritoneal interstitium showed a similar increase in both groups, but mesenteric tissue from the HA group contained more HA (48%, P < 0.01) than tissue from control animals. CONCLUSIONS: The addition of HA to peritoneal dialysis solution decreases protein permeability, increases ultrafiltration, and decreases cytokine levels and the proportion of peritoneal neutrophils in dialysate from rats exposed to hypertonic dialysis solution. These results suggest that exogenous HA may help to protect the peritoneal membrane during exposure to dialysis solutions. These benefits, if sustained in the clinical setting, could lead to improvements in the therapy of peritoneal dialysis.

Effect of N-acetylglucosamine on function of peritoneal leukocytes.

OBJECTIVE: To compare effects of N-acetylglucosamine (NAG)-based and glucose-based dialysis fluids on the function of peritoneal leukocytes in conditions of peritoneal dialysis. DESIGN: In vitro experiments on ex vivo isolated rat peritoneal leukocytes. MATERIALS: Peritoneal leukocytes were isolated from rats on chronic peritoneal dialysis. On alternate days, fluid exchanges were performed with NAG-based or glucose-based dialysis solutions. After a 4-hour dwell, dialysate was drained and peritoneal leukocytes were incubated in vitro +/- lipopolysaccharide (LPS). Production of nitrites (index of NO synthesis), tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and interferon gamma (IFN-gamma) by unstimulated or stimulated peritoneal leukocytes originating from NAG-based or glucose-based fluid was measured. RESULTS: Dialysate cell count was lower during exchanges with NAG-based fluid (2113+/-615 cells/microL) as compared to glucose-based fluid (3643+/-1108 cells/microL; p < 0.01). Differential cell count was similar in both studied groups. Unstimulated peritoneal leukocytes from NAG-based dialysate produced more NO (nitrites) (0.65+/-0.07 micromol per 10(6) cells) than did cells from glucose-based dialysate (0.26+/-0.09 micromol per 106 cells, p < 0.01). Stimulated peritoneal leukocytes from NAG-based dialysate produced more cytokines than did cells from glucose-based dialysate: TNFalpha, 135.2+/-37.0 pg versus 70.2+/-21.8 pg per 10(6) cells respectively, p < 0.01; IL-1beta, 143.2+/-60.9 pg versus 99.1+/-22.4 pg per 10(6) cells respectively, p < 0.05; IFN-gamma, 16.2+/-12.5 pg versus 6.0+/-1.8 pg per 10(6) cells respectively, p < 0.01. CONCLUSIONS: We demonstrated that rat peritoneal leukocytes exposed in vivo to NAG-based dialysis fluid have better ability to produce inflammatory mediators than do peritoneal leukocytes from the same donor, but exposed in vivo to glucose-based dialysis solution.

Bicarbonate/lactate dialysis solution improves in vivo function of peritoneal host defense in rats.

OBJECTIVE: To assess the in vivo peritoneal inflammatory reaction in rats dialyzed with neutral, bicarbonate-lactate-buffered dialysis fluid. METHODS: Chronic peritoneal dialysis was performed for 4 weeks in Wistar rats with two solutions: (1) 40 mmol/L lactate-buffered fluid, pH 5.2, with a glucose concentration of 2.27 g/dL (Lac); and, (2) 15 mmol/L lactate and 25 mmol/L bicarbonate-buffered fluid, pH 7.0-7.5, with a glucose concentration of 2.27 g/dL (Bic-Lac). After 4 weeks, two peritoneal equilibration tests (PET 1 and PET 2) were performed in all animals with each respective solution. PET 1 was done with test solutions alone, whereas, on a subsequent day, PET 2 was performed with test solutions supplemented with endotoxin [lipopolysaccharide (LPS)] to induce peritonitis. RESULTS: During PET 1 no consistent differences were detected in peritoneal permeability between the Lac and Bic-Lac groups. Total dialysate cell count in the Bic-Lac animals was lower than in rats treated with Lac fluid: that is, at 8 hours, the respective counts were 1858+/-524 cells/microL versus 2785+/-1162 cells/microL (p < 0.01). Dialysate from animals dialyzed with Bic-Lac contained more macrophages (at 4 hours: 53.6%+/-35.8% versus 35.8%+/-8.8%, p < 0.001) and fewer neutrophils (at 4 hours: 3.6%+/-1.8% versus 15.4%+/-6.1%, p < 0.001) as compared to those dialyzed with the Lac solution. Concentration of nitrites in 8-hour dwell dialysate samples from Bic-Lac rats was lower than that in the Lac group (0.98+/-0.28 micromol/mL versus 2.32+/-0.87 micromol/mL, p < 0.002), but cytokine levels in the dialysates were comparable. During PET 2, the increase in peritoneal permeability resulting from the LPS-induced inflammatory response was similar for both test solutions. Dialysate cell count was higher in the Lac group versus the Bic-Lac group (at 8 hours: 8789+/-4862 cells/microL versus 3961+/-581 cells/microL, p < 0.001), contained more neutrophils (at 8 hours: 80.0%+/-11.3% versus 54.8%+/-4.4%, p < 0.001) and fewer macrophages (at 8 hours: 6.8%+/-5.6% versus 21.2%+/-3.3%, p < 0.05). During peritonitis, we found a higher overall dialysate concentration of both tumor necrosis factor (TNFalpha: +53%, p < 0.05) and of interferon gamma (IFN-gamma: +303%, p < 0.02), in the Bic-Lac group than in the Lac group. CONCLUSIONS: A lower dialysate cell count, higher percentage of macrophages, and lower percentage of neutrophils in dialysate suggest that Bic-Lac fluid induces a diminished nonspecific inflammatory response of the peritoneal cavity during dialysis. However, after in vivo stimulation, peritoneal cells from animals dialyzed with Bic-Lac solution possess an augmented ability to produce inflammatory cytokines.

Evaluation of the effect of uremia on peritoneal permeability in an experimental model of continuous ambulatory peritoneal dialysis in anephric rats.

Anephric rats were maintained on continuous ambulatory peritoneal dialysis (CAPD). Peritoneal permeability was assessed during a standard 4-hour peritoneal equilibration test (PET) performed with Dianeal 3.86% (Baxter Healthcare, Deerfield, Illinois, U.S.A.). The effect of uremia on peritoneal permeability was evaluated in an experimental protocol in which each animal served as its own control. In each rat, PET1 (control) was performed before removal of kidneys and PET2 (uremia) was performed four days after removal of kidneys. Net ultrafiltration during a 4-hour exchange with Dianeal 3.86% was higher during PET1 (3.8 +/- 2.3 mL) than during PET2 (-1.3 +/- 3.3 mL), p < 0.05. Peritoneal permeability to urea and glucose was similar in both series. Transperitoneal equilibration of creatinine concentration was faster in uremic animals: D/P at 4 hours was 0.94 +/- 0.06 during PET2 versus 0.77 +/- 0.08 during PET1, p < 0.001. The opposite difference was seen for total protein: D/Px 1000 after a 4-hour dwell was 51.4 +/- 19.8 during PET2 versus 70.3 +/- 12.9 during PET1, p < 0.05. Our results show that uremia modifies the permeability of the peritoneum to both water and solutes.

The effect of N-acetylglucosamine as a substrate for in vitro synthesis of glycosaminoglycans by human peritoneal mesothelial cells and fibroblasts.

The effect of N-acetylglucosamine (NAG) on in vitro synthesis of glycosaminoglycans by human peritoneal mesothelial cells and fibroblasts was studied. In contrast to isosmotic concentrations of glucose, NAG increases the synthesis of hyaluronan by mesothelial cells and fibroblasts in a dose-dependent manner. This effect of NAG can be demonstrated in the presence of increased glucose levels in a medium, or in a medium mixed with effluent dialysate obtained from continuous ambulatory peritoneal dialysis (CAPD) patients. Glucose inhibits synthesis of sulphated glycosaminoglycans by peritoneal mesothelial cells and fibroblasts, whereas NAG stimulates their production. Our results demonstrate that NAG is an effective stimulator of the in vitro glycosaminoglycans synthesis by human peritoneal mesothelial cells and fibroblasts.

The characteristics of peritoneal healing after catheter insertion in a rat model of peritoneal dialysis.

The aim of this study was to characterize the process of peritoneal healing after catheter insertion in a rat model of peritoneal dialysis using a 1.36% solution (Baxter Dianeal). After catheter insertion (day 1 of experiment), 12 rats were injected daily with 20 mL of 1.36% dialysis solution for 2 weeks. Every second day a sample of 4 hour dialysate was taken from every rat for biochemical analysis, cell count, cell differentiation, and nitrites measurement. The measured parameters decreased during the experiment and stabilized during the second week after catheter insertion. In cell differentiation, we observed an increase in the number of macrophages, with a parallel decrease in the number of neutrophils that was reflected in a significant decrease in the neutrophils/macrophages ratio. Our results suggest that the process of peritoneal healing after catheter implantation in rats lasts about 2 weeks, and therefore that any biocompatibility study of peritoneal dialysis solutions in rats should be performed at least 2 weeks after catheter insertion.