Living-engineered valves for transcatheter venous valve repair

BACKGROUND

Chronic venous insufficiency (CVI) represents a major global health problem with increasing prevalence and morbidity. CVI is due to an incompetence of the venous valves, which causes venous reflux and distal venous hypertension. Several studies have focused on the replacement of diseased venous valves using xeno- and allogenic transplants, so far with moderate success due to immunologic and thromboembolic complications. Autologous cell-derived tissue-engineered venous valves (TEVVs) based on fully biodegradable scaffolds could overcome these limitations by providing non-immunogenic, non-thrombogenic constructs with remodeling and growth potential.

METHODS

Tri- and bicuspid venous valves (n=27) based on polyglycolic acid-poly-4-hydroxybutyrate composite scaffolds, integrated into self-expandable nitinol stents, were engineered from autologous ovine bone-marrow-derived mesenchymal stem cells (BM-MSCs) and endothelialized. After in vitro conditioning in a (flow) pulse duplicator system, the TEVVs were crimped (n=18) and experimentally delivered (n=7). The effects of crimping on the tissue-engineered constructs were investigated using histology, immunohistochemistry, scanning electron microscopy, grating interferometry (GI), and planar fluorescence reflectance imaging.

RESULTS

The generated TEVVs showed layered tissue formation with increasing collagen and glycosaminoglycan levels dependent on the duration of in vitro conditioning. After crimping no effects were found on the MSC level in scanning electron microscopy analysis, GI, histology, and extracellular matrix analysis. However, substantial endothelial cell loss was detected after the crimping procedure, which could be reduced by increasing the static conditioning phase.

CONCLUSIONS

Autologous living small-diameter TEVVs can be successfully fabricated from ovine BM-MSCs using a (flow) pulse duplicator conditioning approach. These constructs hold the potential to overcome the limitations of currently used non-autologous replacement materials and may open new therapeutic concepts for the treatment of CVI in the future.

In vitro fabrication of autologous living tissue-engineered vascular grafts based on prenatally harvested ovine amniotic fluid-derived stem cells

Amniotic fluid cells (AFCs) have been proposed as a valuable source for tissue engineering and regenerative medicine. However, before clinical implementation, rigorous evaluation of this cell source in clinically relevant animal models accepted by regulatory authorities is indispensable. Today, the ovine model represents one of the most accepted preclinical animal models, in particular for cardiovascular applications. Here, we investigate the isolation and use of autologous ovine AFCs as cell source for cardiovascular tissue engineering applications. Fetal fluids were aspirated in vivo from pregnant ewes (n = 9) and from explanted uteri post mortem at different gestational ages (n = 91). Amniotic non-allantoic fluid nature was evaluated biochemically and in vivo samples were compared with post mortem reference samples. Isolated cells revealed an immunohistochemical phenotype similar to ovine bone marrow-derived mesenchymal stem cells (MSCs) and showed expression of stem cell factors described for embryonic stem cells, such as NANOG and STAT-3. Isolated ovine amniotic fluid-derived MSCs were screened for numeric chromosomal aberrations and successfully differentiated into several mesodermal phenotypes. Myofibroblastic ovine AFC lineages were then successfully used for the in vitro fabrication of small- and large-diameter tissue-engineered vascular grafts (n = 10) and cardiovascular patches (n = 34), laying the foundation for the use of this relevant pre-clinical in vivo assessment model for future amniotic fluid cell-based therapeutic applications.

Arterial hypertension and progression of chronic kidney disease in children during 10-year ambulatory observation

The aim of this study was the long-term retrospective analysis of chronic kidney disease (CKD) progression in children, especially with regard to the presence of hypertension (HTN). The average rate of progression of CKD was higher in patients with HTN than without HTN. Hypertension treatment requires multidrug schemes which need to be intensified with extended time of CKD duration.

Androgens concentrations and second-to fourth-digit ratio (2D:4D) in girls with congenital adrenal hyperplasia (21-hydroxylase deficiency)

OBJECTIVES

Excessive hyperandrogenism, though proper hydrocortisone supplementation is a frequent clinical problem in girls with congenital adrenal hyperplasia (CAH). This may result from autonomic regulation of androgen production established in prenatal life. It has been suggested that the length of the second finger relative to the length of the fourth finger (2D;4D ratio) is negatively related to prenatal testosterone concentration.

DESIGN AND SETTING

The retrospective study aimed to establish the relationship between the level of androgenization in utero determined using 2D:4D ratio and serum androgen concentrations in treated girls with CAH (21-OH deficiency) has been performed on 19 girls with CAH (21-OH deficiency) at the age of 3.7-19 years (mean 13.8 ± 4.07 years). All subjects were adequately treated with hydrocortisone (10-19 mg/m2; mean 13.81 ± 4.07 mg/m2). Anthropometric measurements of digits length were performed in all girls on X-rays obtained for bone age estimation. Apart from it, serum androgens concentrations (testosterone, androstenedione, s-DHEA) and 17-OH-progesterone (17-OHP) were assayed.

RESULTS

Mean androgens serum concentrations in examined group were: testosterone 150.21 ± 155.44 ng/ml; androstenedione 4.15 ± 5.32 ng/ml, s-DHEA 70.39 ± 85.52 µg/dl. Mean 2D:4D ratio was 0.96 ± 0.04. Analysis of correlation showed positive linear correlations between testosterone, s-DHEA and 2D:4D ratio (r=0.53, p=0.023 and r=0.53; p=0.019, respectively).

CONCLUSIONS

2D:4D ratio parameter may be a simple test in indentification of female CAH patients prone to excessive androgen secretion despite proper treatment. The autonomization of adrenal androgens production in foetal life may cause its elevated levels in female patients with CAH although treated adequately.

Successful pregnancy in a chronically hemodialyzed patient with end-stage renal failure

A 36 year-old female with chronic kidney failure due to hypertension and who was being treated with hemodialysis for eight months, was admitted to the hospital on the suspicion of being pregnant. Gynecological examination and ultrasound scan confirmed the pregnancy. Gestation was diagnosed in the 29^th week after the patient felt fetal movements. Intensification of the dialysis treatment was started immediately after the diagnosis was made.

Theoretical analysis of solvent effects on nitrogen NMR chemical shifts in oxazoles and oxadiazoles

Using quantum chemistry methods we have evaluated the solvent effects on the (14)N NMR chemical shifts in five oxa- and oxadiazoles dissolved in twelve solvents. These solvents differ in their polarity with the dielectric constants varying from 2 to 80. Moreover, three of them have a hydrogen-bond donor character. All possible hydrogen-bonding in the water solution with the oxygen and nitrogen (hydrogen-acceptor) centers in oxazoles (2) and oxadiazoles (3) have been considered in our studies. It has been shown that both the pure solvent and hydrogen-bonding effects are significant and result in (14)N magnetic shielding increase. In water solutions the pure solvent effect is larger than the hydrogen-bonding effect. In addition, the solvent effect has been analyzed in terms of its direct and indirect contributions. It should be emphasized that our theoretical results for (14)N chemical shifts in oxa- and oxadiazoles remain in a very good agreement with the accurate experimental data.

Diurnal rhythm of blood pressure, heart rate and adrenergic activity in patients with normotension treated with continuous ambulatory peritoneal dialysis and haemodialysis

PURPOSE

People with normotension and with essential hypertension are subjected to the diurnal rhythm of blood pressure (BP) with higher values during the day than during the night. Among dialysed patients nocturnal reduction of BP is blunted. The aim of the study was to evaluate diurnal BP rhythm and adrenergic activity measured as values of catecholamines.

MATERIAL AND METHODS

Study was performed among dialysed patients with normotension: 13 haemodialysed patients (HD), 8 patients treated by continuous ambulatory peritoneal dialysis (CAPD) and 10 controls (C). Ambulatory BP monitoring (ABPM) was done by using Micro SJ7400 AMP device. Catecholamines concentrations were measured by HPLC-ED method before and after cold pressure test.

RESULTS

There was no significant difference between manual measurements of BP done by dialysis nurses and mean values of 24-hours ABPM in CAPD group and C group and 48-hours ABPM among HD patients. Diurnal BP was blunted in 80% of HD patients during the day of haemodialysis, 70% during the day without haemodialysis and in CAPD group in 50%. Heart rate (HR) variability was comparable in HD and CAPD groups and significant lower than in C group. Baseline noradrenaline (NA) as well as NA (ng/ml) post cold pressure test levels were significantly higher among HD patients (463 +/- 21, 546 +/- 31) and CAPD patients (452 +/- 76, 527 +/- 92) as compared with C (206 +/- 53*, 315 +/- 61*). (x +/- SD), *p<0.001

CONCLUSIONS

Despite increased adrenergic activity and altered diurnal rhythmof BP and HR exist in dialysed patients we didn't find directly relationship. Another or composed factors couldaffect diurnal rhythm of BP and HR.

Chlamydia trachomatis infection in chronically hemodialyzed patients

PURPOSE

In the general population there is association between Chlamydia trachomatis (Ch. trachomatis) infection and reactive arthritis (RA). RA is a systemic illness characterized by inflammatory synovitis. Arthritis tends to be oligoarticular and involves mainly the lower limbs. The aim of this study is to assess the age and sex specific prevalence of Ch. trachomatis infection in dialysis population and to find possible relationship between manifestation of infection and renal osteodystrophy.

MATERIAL AND METHODS

The study was conducted in 53 patients: 22 women (W) and 31 men (M), with a mean age of 58.1 +/- 15 years, treated with HD for 28.5 +/- 28.2 months. The Ch. trachomatis infection was assessed by the detection IgG antibodies for Ch. trachomatis. Also some other biochemical parameters of osteodystrophy, inflammation and malnutrition were measured.

RESULTS

The presence of a high titre of anti-Ch. trachomatis antibodies was found in 22 patients--41% [G IgG (+)]. Mean level of anti-Ch. trachomatis antibodies was significantly higher in G IgG (+) than in seronegative patients [G IgG (-)]: 19.0 +/- 8.6 vs 4.0 +/- 2.1 U/ml, p<0.001. There was no difference in mean age of seropositive and seronegative patients for Ch. trachomatis (62.4 +/- 13.1 vs 56.2 +/- 15.9 years). We did not observe in both groups of patients any differences in mean level of C-reactive protein (CRP): 12106.2 +/- 10791.0 vs 14015.3 +/- 11194.3 ng/ml. The mean ferritin level was significantly higher in G IgG (+): 624.3 +/- 375.7 vs 418.3 +/- 341.4 ng/ml, p<0.05. Significant negative correlations were found in G IgG (+) between IgG antibodies and transferrin saturation (r=-0.645719, p<0.001) and between CRP and calcium (r=-0.4526, p<0.05). IgG antibodies were detected frequently in W (60%) than in M (29%). Mean level of IgG was significantly higher in seropositive W than in seropositive M (23.3 +/- 7.8 vs 12.1 +/- 4.2 U/ml, p<0.0001). The seropositive W were older (67.9 +/- 11.8 vs. 53.8 +/- 11.0 years, p<0.02) and seropositive W were shorter treated with HD (18.1 +/- 16.6 vs 43.7 +/- 30.6 months, p<0.02). The mean serum calcium conc. and phosphorus were significantly lower in seropositive W (2.1 +/- 0.1 vs 2.3 +/- 0.2 mmol/l, p<0.05 and respectively 1.3 +/- 0.3 vs 1.8 +/- 0.2 mmol/l, p<0.005). Likewise the mean transferrin saturation (TS) was significantly lower in that group (25.7 +/- 7.3 vs 38.0 +/- 11.3%, p<0.01). There were no differences between seropositive men and women in mean serum concentrations of CRP, iPTH, albumin and hemoglobin. We found in seropositive W significant negative correlation between IgG antibodies and age (r=-0.633, p<0.02).

CONCLUSIONS

The patients treated with HD were quite frequently shown significantly elevated level of IgG antibodies for Ch. trachomatis. It could have be connected with past infection. The antibodies were more commonly detected in women, particularly in younger patients. No relationship between osteodystrophy and Ch. trachomatis infection was found.

Low-T3 syndrome and signal-averaged ECG in haemodialysed patients

The study was designed to evaluate the potential link between low-T3 syndrome and signal-averaged ECG parameters (SAECG) in a group of hemodialyzed patients (HD-pts). 52 selected HD-pts (without relevant thyroid and cardiac diseases) were included. SAECGs were performed postdialysis together with evaluating free triiodothyronine (fT3), free thyroxine (fT4), reverse triiodothyronine (rT3), thyroid stimulating hormone levels and echocardiography. For each SAECG, QRS duration (QRSd), root-mean-square voltage of the terminal 40 ms of the QRS (RMS40), and low-amplitude signal duration (LAS40) were measured. Abnormal SAECGs were found in 30.8 % of HD-pt. HD-pts with decreased fT3 and increased rT3 values (low-T3 positive) revealed higher QRSd and LAS40 values in comparison with low-T3 negative HD-pts (p = 0.019, p < 0.001 respectively). Low-T3 positive HD-pts had lower RMS40 values than low-T3 negative patients (p < 0.001). The Pearson test showed significant correlations between QRSd and fT3 (r = -0.592, p < 0.001); QRSd and rT3 (r = 0.562, p < 0.001); RMS40 and fT3 (r = 0.432, p = 0.009); RMS40 and rT3 (r = -0.325, p = 0.025). On multivariate analysis, both fT3 and rT3 levels were found to be independent predictors of QRSd and RMS40 values. Our study showed that decreased fT3 and increased rT3 concentrations due to low-T3 syndrome influence SAECG parameters in HD-pt.

Changes of endogenous erythropoietin level and iron status during a 30-month hemodialysis treatment of a group of patients

In our earlier paper we found that among 50 hemodialysis patients (HD pts) 48% (24 pts) control anemia with hemoglobin (Hb) concentration >9.5 g/dl and hematocrit (Hct) >30% without recombinant human erythropoietin (rHuEpo) therapy. These HD pts had significantly higher mean endogenous erythropoietin (eEpo) level and lower iron reserves (IR) than HD pts who need rHuEpo therapy. The aim of this study was to judge whether the possibility to control anemia in pts not requiring rHuEpo therapy changes during a 30-month HD treatment. Serum eEpo and ferritin were measured every 6 months. After 30 months of HD treatment 18 pts remained in this group--5 pts died, 1 underwent transplantation. During the study period 4/18 pts permanently had a very low level of eEpo (under detection limit), 7/18 had the level of eEpo within normal range for healthy control, 7/18 pts had a high level of eEpo (up to 3 times higher than the mean for healthy control). Pts who had the highest level of eEpo had the lowest IR. After 30 months IR were significantly lower than at the beginning of observation (292 +/- 87 vs 143 +/- 127 mg). Important negative correlation between eEpo and IR was observed throughout the whole period of study: r = -0.4820, p < 0.02 at the start of the study, and r = -0.6126, p < 0.007 after 30 months of treatment. The study shows that the possibility to control anemia in pts not treated with rHuEpo did not change significantly during 30 months of HD treatment. Endogenous Epo level in HD pts not treated with rHuEpo varied between different pts: it was permanently low in some pts, permanently high in others and stayed normal in remaining pts.

[Effect of vitamin E-modified membrane on expression of coreceptors CD4, CD8 on lymphocytes in chronic hemodialysis patients]

Chronic renal failure induces a clinical state of cellular and humoral immunodeficiency that also depends on the time duration of blood contact with the wide spectrum of dialysis membranes use during long-term hemodialysis treatments. In end stage renal failure (ESRD) patients it is possible to induct state of chronic inflammation mostly caused by leukocytes and complement activation. It is postulated that the vitamin E-coated dialysis membrane minimalizes unbiocompatible reactions that generate smaller amounts of reactive oxygen species (ROS). The purpose of this study was to analyze the effect of classical and vitamin E coated cellulose membranes on the expression of CD 4 and CD 8 adhesion molecules on lymphocytes during HD in 10 patients using flow cytometric analysis. The study protocol included the measurement of molecules expression using cellulose membrane (Clirans RS15, TERUMO Corp., Japan), and the same membrane coated by vitamin E (Excebrane, Clirans E15, TERUMO Corp., Japan) during 20 dialysis sessions with each kind of membrane. During dialysis with classical cellulose membrane, significant decrease of lymphocyte serum level and increase of lymphocyte CD4 expression was observed. During the session with vitamin E coated membranes we did not observe any significant changes in serum CD4, CD8, CD4+8+ lymphocyte level, and also lymphocyte CD4, and CD8 expression on lymphocytes. Our findings suggest the potential role of vitamin E-coated cellulose membrane to minimalize negative reaction of the T lymphocyte subpopulation in ESRD patients treated on long-term dialysis.

[Late abdominal wall leaks of dialysis fluid--own experience in conservative treatment]

The late abdominal wall leaks (LAWL) of dialysis fluid is a serious technical complication of continuous ambulatory peritoneal dialysis (CAPD). Manifestation of LAWL is a significant diagnostic and therapeutic problem. The aim of our study was to establish of diagnostic procedure and the methods of treatment of LAWL. The group of 80 patients treated with CAPD was observed during one-year-period. LAWL appeared in 8 patients from this group. LAWL was diagnosed by: physical examination, abdominal circumference measurement, ultrasound examination of abdominal wall. Patients with LAWL were temporary transferred from CAPD to automated peritoneal dialysis (APD). After applied treatment the remission of leakage was observed. Basing on performed observation we concluded, that physical examination, abdominal circumference measurement and ultrasound examination of abdominal wall are the basal diagnostic methods of LAWL and that temporary change of dialysis method from CAPD to APD is an effective method of LAWL treatment.

Effect of vitamin E modified cellulose membrane on human lymphocyte, monocyte, and granulocyte CD11b/CD18 adhesion molecule expression during hemodialysis

Chronic renal failure induces a clinical state of immunodefi ciency that also depends upon a wide spectrum of dialysis membranes used during hemodialysis. Previous studies have shown that cellular immunodeficiency is caused by malfunc tion of the antigen presenting cells (monocytes or granulocytes). Subsequent activation of rolling mononuclear leuko cytes results in up-regulated expression of CD11b/CD18 (Mac-1) on endothelial cells. It is postulated that a VitE coated dialysis membrane might minimize the membrane biocompatibility, thereby generating a smaller amount of re active oxygen species (ROS). The purpose of this study was to evaluate the expression of the CD11b/CD18 adhesion mole cule on lymphocytes, monocytes, and granulocytes during HD in 10 patients, using flow cytometric analysis. The study protocol included the measurement of molecule expression using cellulose membrane (Clirans RS15, TERUMO Corp. Japan), and the same membrane coated by vitamin E (Exce brane, Clirans E15, TERUMO Corp., Japan) during 20 dialysi sessions each. Lymphocyte CD11 b/CD1 8 (Mac-1) expression did not change with either dialyzer type. However, monocyt (p = 0.046) and granulocyte (p = 0.018) CD11b/CD18 ex pression in the post HD period was significantly lower using the vitamin E coated membrane compared with the contro cellulose membrane. Our findings suggest a significant de crease in activation and migration of monocytes and granu locytes when using a vitamin E coated cellulose membrane.

Searching for a genetic risk profile in end-stage renal disease

There is a strong evidence that both, genetic factors and environment, affect the development of end-stage renal disease (ESRD). The factors that initiate renal failure are probably different from those contributing to its progression. Some factors involved in the progression of nephropathy are already identified, like elevated blood pressure, hypercholesterolemia or hyperparathyroidism. Molecular genetic techniques are extensively applied to developing strategies for detection of human renal failure genes. The candidate gene approach for finding an association between polymorphic DNA markers and disease was successfully used in studying genes of the renin-angiotensin system, especially those coding angiotensin I-converting enzyme, angiotensinogen and angiotensin type 1 receptor. Several other genes, for example growth factors and cytokine genes, nitric oxide synthase or genes of the kallikrein-kinin system are being evaluated using this approach. Identification of candidate genes associated with end-stage renal disease will create a need for testing several disease loci simultaneously. Subsets of predictive genetic markers will be developed for routine use in clinical practice. Recognizing genetic changes affecting the initiation and progression of renal failure will have important clinical implications, involving testing individuals who are genetically susceptible but yet unaffected. It will make possible identification of individuals at a higher risk for renal failure and help in the choice of diagnostic tests as well as in planning therapeutic interventions.

Effect of recombinant human erythropoietin on adrenergic activity in normotensive hemodialysis patients

Ten normotensive hemodialysis patients with severe anemia participated in the study. Human recombinant erythropoietin (rHuEpo) was administered i.v. 3 times a week in doses of 50 U/kg of body weight. During 12 weeks of observation, the mean hematocrit value increased from 19%, before start of therapy, to 32%. Simultaneous monitoring of serum plasma noradrenaline (NA) concentration showed an elevation from 202 to 281 pg/ml. An increase of NA concentration after a cold pressure stimulating test (CP) was not statistically significant after as compared to before treatment, but became statistically significant after 12 weeks of rHuEpo therapy (281 pg/ml before to 441 pg/ml after CP test, p < 0.01). The mean arterial blood pressure increased from 92 - 109 mmHg after 12 weeks of rHuEpo therapy (p < 0.001). We have demonstrated significantly increased NA blood concentrations after 12 weeks of rHuEPO therapy in normotensive patients, which correlated with increased MAP. This may suggest that the observed increase of noradrenaline concentration as a vasoactive substance after the CP test may contribute to hypertension during rHuEPO therapy.

Rate of Staphylococcus aureus nasal carriage in immunocompromised patients receiving haemodialysis treatment

Specimens from the nose and throat were collected from 28 long-term haemodialysed patients. Staphylococcus aureus strains were isolated from sixteen patients who been on haemodialysis for over 113 months. Cytokine levels, as well as full blood cell differential counts and cell surface antigens were determined in these patients. The serum concentration of TGF-beta was significantly higher in patients carrying Staphylococcus aureus. CD14 and HLA-DR molecule expression on monocytes, as well as NK cell percentage was significantly different in S. aureus carriers. Our preliminary results suggest that immune status imbalance in haemodialysed patients could be related to the high incidence of S. aureus nasal carriage and infections.

[Measurement of fluid compartments using electrical bioimpedance for assessment of target weight in hemodialysis patients]

The prescription of optimal hydration status in hemodialysis patients remains a much disputed topic in dialysis treatment. In particular, assessment of the patients optimal weight ("target weight") poses considerable difficulties. Multifrequency bioimpedance spectroscopy analysis (BIS) has been recommended as a non invasive, practical, and relatively non expensive method to determine hydration and nutritional status in patients on maintenance hemodialysis (HD). In the current study we used whole body BIS analysis for determination of body water (BW) compartments; total body water (TBW), extracellular water (ECW), and intracellular water (ICW) in 133 healthy adults, and in 227 hemodialysis patients with end-stage renal disease. BIS results were compared to anthropometric measurements. Our results showed strong correlation between TBW measured by BIS in control group in comparison to anthropometric calculation (p = 0.001). In HD patients we observed higher range of TBW, and TBW/ECW ratio (from 15.6 to 56.1 L and from 0.33 to 0.78), as measured by BIS at pre-HD, and also post-HD period (TBW ranged from 13.1 to 56.2 L, ECW/TBW ratio ranged from 0.33 to 1.27). The TBW BIS results did not correlate with anthropometric calculation. We postulate using of multi-frequency bioimpedance technique in precise determination of fluid compartments and in consequence in the assessment of "target weight" in hemodialysis population.

[Renin-angiotensin system genes in chronic glomerulonephritis]

Glomerulonephritis is a group of diseases with complex etiology, pathogenesis, morphological features and clinical course. The renin-angiotensin system genes are important group of candidate genes involved in pathogenesis of chronic renal diseases. The purpose of our study was to analyze the association of genetic polymorphisms of these genes with glomerular kidney diseases. The study population consisted of 52 patients with immunological glomerular kidney diseases and 50 hemodialyzed patients with end-stage renal failure with glomerulonephritis as primary disease. The control group consisted of 200 healthy subjects. By means of the polymerase chain reaction (PCR) the following polymorphisms were evaluated: insertion/deletion (I/D) polymorphism in intron 16 of the angiotensin-converting enzyme gene (ACE), M235T polymorphism of the angiotensinogen gene (AGT) and A1166C polymorphism of the angiotensin II type 1 receptor gene (AT1R). No significant association was found between the ACE allele and genotype frequencies and the disease. The allele frequency of the M235T polymorphism was different from that observed in the control group, but differences in the genotype distribution were not statistically significant. The CC genotype of the AT1R gene polymorphism was significantly more frequent in patients than controls. This suggests an increased susceptibility to renal diseases in individuals carrying the CC genotype. This relationship is not associated with hypertension. Our results suggest that in the Polish population the AT1R gene polymorphism might be associated with increased susceptibility to chronic renal diseases.

[Relationships between hyperparathyroidism and Helicobacter pylori infection in long-term hemodialysis patients]

In the accessible literature we did not find data about the connection between Helicobacter pylori (H. pylori) infection and parathyroid hormone (PTH) abnormalities in patients on hemodialysis (HD pts). It is known that hyperparathyroidism is connected with stimulation of gastrin synthesis as well with increased acidity of gastric juice. We speculate that it should be connected with susceptibility to H. pylori infection in HD pts. The aim of our study was the assessment of relationships between PTH abnormalities and parameters of H. pylori infection expressed by concentration of IgG antibodies against H. pylori and histologically performed urease test. The study was conducted in 65 (37 M, 28 F) stable HD pts. They were dialyzed for 6 to 288 months (102.9 +/- 84.5). Simultaneously in 25 HD pts qualified for renal transplantation biopsy specimens taken during gastroscopy were examined by a histological test and urease test (CLO-test). According to the PTH concentration HD pts were divided into 3 groups with PTH < 100 pg/ml; with PTH 100-350 pg/ml and with > 350 pg/ml. Positive IgG H. pylori test > 24 U/ml was found in 60 (92%) HD pts. Mean IgG H. pylori concentration was similar in tree groups of HD pts. (82 vs 91 vs 88 U/ml) and did not differ significantly from control group. We found significant negative correlation between IgG H. pylori concentration and time on dialysis therapy (r = -0.50067, p = < 0.0001). Positive test in biopsy specimen was found in 14 HD pts (56%). PTH level in this group of HD pts not differ significantly from PTH level in pts with negative test (426 vs 398 pg/ml) and IgG H. pylori concentration was significantly higher in positive pts than in negative pts (104 vs 48 U/ml).

CONCLUSION

We did not find significant relationship between PTH abnormalities and H. pylori infection in HD pts. Longer period of dialysis therapy is connected with decreased ability to produce antibodies againts H. pylori.

[Use of bioimpedance spectroscopy techniques for monitoring fluid balance in patients with end stage renal failure]

Adequate body hydration is considered the key element of fluid management in critically ill patients including group with end stage renal failure. Bioimpedance technique is widely used as a non-invasive, simple and accurate method to measure body composition. The purpose of the paper was to prescribe the using of single, and multifrequency bioimpedance spectroscopy technique for estimation of fluid balance in end-stage renal patients. We also discussed some measurements and data modelling problems, including postural change effect, and intercompartmental fluid shift during dynamic monitoring of fluid balance.

[Effect of arterio-venous fistula blood flow dynamics on ECG abnormalities in chronic hemodialysis patients]

The dialysis doses is mostly dependent on well functional permanent vascular access. From the other hand high vascular access blood flow (Qva) may induce cardiac problems in HD patients. The purpose of this study was to investigate the effect of vascular access dynamics on electrocardiographic abnormalities in hemodialysis patients. Therefore, forty non-diabetic, HD patients, with native vascular access (VA) were divided into two equal groups; with Qva > 1500 ml/min (group A), and also Qva < 1500 ml/min (group B). The average of VA survival period was 28 +/- 18 (mean +/- SE) (group A), and 29 +/- 15 (months) (group B). The Qva measurements monitoring by color Doppler sonography included also: maximal velocity (Vmax), time average of maximal velocity (TAMX), pulsate index (PI), and resistive index (RI). Kt/V index was calculated, as classical parameter of adequacy, and also shunt recirculation using 3 urea samples was measured. For estimation of cardiac function we used M-mode echocardiography, and 24-hours ECG (Holter) monitoring. The occurrence of ventricular (VE), and supraventricular extrasystoles (SVE), ST-T, and ST characteristic as well were monitored by 24-hours Holter.

CONCLUSIONS

1. In the group with high Qva (A) we observed significantly higher number of VE, and also of SVE recorded by Holter monitoring compared with the low Qva group (B). 2. The mean number of patients with ST-T changes was higher in group A (12 vs. 7), but number of patients with recorded by Holter ST depression, and ST elevation between investigated groups were similar. 3. The mean number of ventricular arrhythmias of Lown classified as 4A, and 4B of Lown grading was significantly higher in the group with high Qva (A).

[Selected aspects of rehabilitation programs for hemodialyzed patients in the United States ]

The purpose of the paper was to evaluate some aspects of U.S. rehabilitation programs, and medical health systems legislatives initiatives in the patients with end-stage renal diseases treated with hemodialysis. We signalized potential problems, and complications of rehabilitation in such group of patients. The potential improvement in quality of life after intradialysis, and interdialysis rehabilitation was discussed.

[Evaluation of the relationship between possible control of anemia in hemodialysis patients and the concentration of leptin]

There are many growth factors (GFs), which stimulate the proliferation and maturation of erythroid progenitors. The main one is erythropoietin (Epo). Epo acts in concert with other GFs. Recently it was suggested that leptin (Lep) could be involved in a very early stage of erythropoiesis (E). The aim of this study was to analyse the relations between ability of idiopathic compensation of anemia by hemodialysis patients (HD pts) and concentration of Lep in HD men and women separately. The study was performed in 25/13M, 12F/HD pts, who idiopathically compensate anemia (group 1) and 29/16M, 13F/HD pts who required rHuEpo therapy (group 2). The mean Lep level in all women together was significantly higher than in all HD men together (26.9 +/- 6.3 ng/mL vs 6.8 +/- 0.9 ng/mL) but BMI was similar in men and women. We did not find significant differences in level of Lep in both studied groups of HD pts. Perhaps the lower influence of Epo and testosterone on E in HD women is compensated by significantly higher Lep concentration.

Subcutaneous r-HuEPO therapy in CAPD patients: dose determination and clinical experience

We present our results on the efficacy and safety of low dose r-HuEPO given subcutaneously in the treatment of anaemia in CAPD. We have studied 10 stable patients (5 males, 5 females) on CAPD. In our study subcutaneous r-HuEPO was administered twice a week for 6 months. Mean initial dose of r-HuEPO was 67.3+/-21.7 U/kg/week, and maintenance dose was 35.8+/-12.1 U/kg/week. The target Hb concentration was 10-12 g/dl. All patients responded to r-HuEPO. During treatment significant increases of haemoglobin concentration (p<0.05), haematocrit (p<0.05), red cell count (p<0.05) and reticulocyte count (p<0.05) were observed. We found no significant changes in total white cell or platelet counts. Long-term r-HuEPO treatment did not influence significantly plasma levels of electrolytes (Na, K, Ca), urea and creatinine. We found no significant changes in ultrafiltration volumes. In the present study the mean systolic and diastolic blood pressures did not change. Liver function tests were normal at the beginning and at the end of the study. r-HuEPO treatment was associated with a decrease of ferritin (455+/-90 vs. 224+/-83 microg/l. Oral or intravenous iron substitution became necessary in 6 patients. Side effects in our study were minimal; one patient had myalgia after the first seven doses but this disappeared as treatment was continued. Two patients reported pain (mild) at the injection site. In the present study, the correction of anaemia was accompanied by a substantial improvement in the quality of life, mainly in capacity for work, household and social activities.

[Pulmonary embolism as a complication of nephrotic syndrome--case report and therapeutic management]

A case of a 41-year-old man, who was treated due to severe steroid and immunoresistant nephrotic syndrome is described. During the pulsed steroid therapy the patient underwent a pulmonary embolism and developed the post-infarction cavern and abscess of the lung. In this study the case history, complications, diagnostic procedures and therapeutic management were described. The probable mechanism of the described complications was carefully discussed.

Serial cytokine changes in peritoneal effluent and plasma during peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD)

OBJECTIVE AND DESIGN

Secretion of IL-2 and sIL-2R in the peritoneal dialysis fluid and in the peripheral blood during peritonitis with reference to the process of IL-6 and IL-8 release were investigated.

SUBJECTS

17 patients with end-stage renal disease, treated with continuous ambulatory peritoneal dialysis.

METHODS

ELISA method using commercial kits, Genzyme Corp Boston and DAKO.

RESULTS

Markedly increased IL-6 (mean; 2895 +/- 1360 pg/ml) and IL-8 concentration (1459 +/- 966 pg/ml) in drain dialysate fluid at the onset of peritonitis, started to drop rapidly in the successive samples after antibiotics had been administered. Statistically significant increase of IL-2 (197 +/- 92 pg/ml) and sIL-2R (287 +/- 79 pg/ml) was observed 16 h later and kept increasing until reaching the peak after 24 h.

CONCLUSION

Secretion of IL-6 and IL-8 pro-inflammatory cytokines which are mainly synthesized in mesothelium cells is followed by the activation of lymphocytes, their infiltration and the production of T lymphocyte derived IL-2 and sIL-2R.

Influence of some immune factors on the IL-6 and soluble IL-2 receptors in haemodialysed patients

In respect to the immune deficiency state of long-term haemodialysed patients, both cytokines and their receptor disturbances have been taken into consideration. The purpose of our study was to evaluate the effect of uraemic and haemodialysis factors on the interleukin-6 and interleukin-2 soluble receptor levels and the reactivity after influenza vaccination. We have found that IL-6 and IL-2 receptor levels were statistically significantly elevated (98.8 +/- 39 pg/ml and 1557 +/- 544 U/ml, respectively) in serum of haemodialysed patients. The fact that increased immune complexes statistically correlated with soluble IL-2 receptor levels (p < 0.01) was very interesting for us. In order to study the immunological response after vaccination, 10 patients have been investigated after influenza vaccination. Plasma samples were collected before, as well as 1 and 4 weeks after vaccine administration. Antibody titres measured by haemagglutinin inhibition showed decreased antibody levels in haemodialysed patients. We conclude that the interleukin disturbance and the elevated interleukin-2 receptor levels together with the presence of circulating immune complexes can influence in some way the immune response of haemodialysed patients.

Plasma erythropoietin level and iron reserves in haemodialysis patients with and without acquired cystic kidney disease

Concentration of erythropoietin (Epo) and iron reserves (IR) belong to the essential factors determining erythropoiesis in haemodialysis patients. Patients on dialysis with acquired kidney disease (ACKD+) can control anaemia better than patients without acquired kidney disease (ACKD-). Therefore we decided to check if plasma Epo levels and IR differ significantly in both groups of patients. Forty chronically haemodialyzed patients after ultrasound diagnosis were divided into 18 patients (45%) with ACKD+ and 22 (55%) without ACKD-. In both groups of patients we compared their plasma levels of Epo and IR. Plasma erythropoietin and ferritin levels were measured by enzymatic immunoassay. Iron reserves were estimated by the formula: IR = 400 x [ln (ferritin)-ln (50)]. In the ACKD+ group 72% of patients and in the ACKD- group 32% of patients did not require rHu Epo therapy. Plasma levels of erythropoietin and iron reserves did not differ significantly between ACKD+ and ACKD- patients. There must be also other factors than erythropoietin levels and iron reserves regulating erythropoiesis in these patients.

Influence of intraperitoneal vancomycin on peritoneal dialysis efficiency. A clinical study

Peritonitis is a major complication of intermittent peritoneal dialysis (IPD); over 70% of the infections are caused by Gram-positive bacteria. Vancomycin (V) is the antibiotic of choice in the treatment of peritonitis caused by G(+). The influence of vancomycin on peritoneal transport in IPD patients has not been described before. We have investigated the effect of intraperitoneal vancomycin on dialysis efficiency in 8 IPD patients using dialysis solutions containing either lactate or acetate. The following parameters were measured: net ultrafiltration (UF), concentration ratios (D/P) of urea, creatinine, potassium, peritoneal clearances (ml/min) of urea, creatinine, potassium, mass transfer of sodium (MTNa), sodium sieving index (SCNa). It has been found that vancomycin significantly decreases D/P urea (p < 0.05) and creatinine (p < 0.05). We found also a significant decrease of mean clearance of urea (p < 0.05) and creatinine (p < 0.05). The mean clearance of potassium did not change significantly. There was no significant change in UF, MTNa, and SCNa. Our preliminary data suggest that vancomycin decreases the permeability of peritoneum for certain low molecules in IPD patients which may have a negative impact on dialysis efficiency.

[Comparison of the ability to control anemia in patients on hemodialysis and peritoneal dialysis considering iron reserves and plasma erythropoietin]

It is known, that patients undergoing CAPD have less severe anaemia than those receiving hemodialysis (HD). In addition they require smaller doses of rHuEpo to control anaemia than HD pts. We have decided to compare plasma erythropoietin (pEpo) and iron reserves (IR) in these both groups of pts. 17 pts on CAPD and 50 pts on HD were diagnosed. 35% pts on CAPD and 52% pts on HD required permanent rHuEpo treatment to maintain hemoglobin (Hb) concentration above 9.5g/dl and Ht above 30%. Plasma EPO and ferritin levels were measured by enzymatic immunoassay. IR were estimated by formula: IR = 400x [ln (ferritin) - ln(50)]. Compared to CAPD, HD pts had higher IR (405 +/- 76 vs. 358 +/- 120 mg) but differences are not statistically significant. Plasma Epo level (geom. mean) was statistically significant higher p = 0.025 in HD pts compared to CAPD pts (8.68, range 2-53 vs. 5.21 range 2-15 mV/ml) Hb concentrations did not differ significantly between pts on CAPD and HD. CAPD pts controlled anaemia better than HD pts despite lower concentration of endogenous erythropoietin.

[Complication due to intraperitoneal dialysis catheter insertion]

During the last 6 years 300 stylet and Tenckhoff catheters were inserted into the peritoneal cavity. In 5 cases an abdominal viscus has been perforated or injured. The complications were twice a perforation of bowel, twice a perforation of bladder and once an injury of aorta. The authors discussed the therapeutic procedure (conservative or operative) and the late consequences of those complications.

Comparison of plasma erythropoietin concentrations and iron status in hemodialyzed patients not requiring and requiring rHuEpo therapy

Fifty patients treated with chronic hemodialysis (HD) were observed for 1 year. 24 of them (48%) did not require treatment with recombinant human erythropoietin (rHuEpo) (group I) because the permanent hemoglobin (Hb) concentration was > 5.9 mmol/l (9.5 g/dl), hematocrit > 30%. The remaining 26 patients (group II) permanently or periodically required rHuEpo treatment. After 6 months of initial observation and after 6 months of clinical study we made a comparison of endogenous erythropoietin (Epo) and iron status in two groups of patients. Patients not requiring treatment with rHuEpo had statistically significant higher Epo concentration and lower iron reserves than patients on rHuEpo treatment. We did not find significant differences in Hb, albumin and creatinine between patients in both groups. Hb concentration did not correlate with the level of Epo, serum creatinine, transferrin saturation, ferritin, iron reserves and time of dialysis therapy in both groups. In both groups we found a significant negative correlation between the concentration of Epo and iron stores. Our results indicate that in patients on HD treatment, plasma Epo level appears to depend either directly or indirectly on iron status.