Hemodialysis and the Acute-Phase Response in Chronic Uremic Patients

In comparison with healthy persons, chronic uremic patients on regular hemodialysis treatment had significantly higher blood serum concentrations of α1-acid glycoprotein, ceruloplasmin and C4 complement component, while levels of haptoglobin, C3 and transferrin were lower. Serum α2-macroglobulin and α1-antitrypsin levels were similar in both groups. Hemodialysis with cuprophan membrane induced only slight changes in some of these glycoproteins during a 48-hour follow-up period. Seven hours after termination of hemodialysis slight, but significant, decreases in blood serum transferrin and α1-antitrypsin concentrations were observed. Hemodialysis thus does not seem to induce a conspicuous acute-phase reaction.

Alterations of erythrocyte structure and cellular susceptibility in patients with chronic renal failure: effect of haemodialysis and oxidative stress

The aim of this study was to investigate erythrocytes rheological behaviour, membrane dynamics and erythrocytes susceptibility to disintegration upon strong oxidative stress induced by dialysis or by external H(2)O(2) among patients with CRF. EPR spectrometry was used to investigate alterations in physical state of cellular components. Generated ROS production induced: (1) significant increase of membrane fluidity in CRF erythrocytes treated with H(2)O(2) (p<0.005) and at 60 min of haemodialysis (p<0.05), (2) significant decrease of cytoskeletal protein-protein interactions (p<0.005) and (3) cellular osmotic fragility (p<0.0005). H(2)O(2) exacerbated these changes. Erythrocytes from CRF patients have changed rheological behaviour and present higher susceptibility to disintegration. Erythrocytes membrane characteristics indicate that CRF patients possess younger and more flexible cells, which are more susceptible to oxidative stress. This may contribute to the shortened survival of young erythrocytes in CRF patients.

[Blood serum and neutrophil amino acid concentrations during hemodialysis]

The abnormal amino acid profile and altered distribution of some amino acids between the extra- and intracellular compartments is currently recognized as a part of metabolism abnormalities in hemodialyzed uremic patients associated with prognosis. The aim of this study was to investigate the pattern of HD influence on the extra- and intracellular amino acid concentrations in neutrophil homogenates and in blood serum. Before HD, the concentrations of arginine (64 vs 33 micromol/l) and cysteine (70 vs 40 micromol/l) were significantly higher in the uremic blood serum, but the concentrations of five amino acids, i.e. serine, threonine, alanine, proline, and valine, were significantly decreased in the uremic serum. The concentrations of arginine (7.95 vs 5.2 micromol/l), tyrosine (14.3 vs 12.5 micromol/l) and phenylalanine (10.7 vs 9.5 micromol/l) were significantly elevated in neutrophil homogenate from uremic patients before HD and after HD for arginine (8.73 micromol/l). We found a substantial increase of blood serum arginine concentration at all evaluated time points of HD from 64 to 191 micromol/l. The concentration of 8 amino acids were found to be significantly decreased in blood serum during HD. We may assume amino acid concentration changes in chronic uremia partly attributed to malnutrition, may be actually associated with inflammatory pathomechanisms, the hypothesis worth verifying in further studies.

[Physiopathology of advanced age]

The paper presents basic changes in the cell structure and function and organ dysfunctions related to advanced age.

Increased hydrogen peroxide in the exhaled breath of uraemic patients unaffected by haemodialysis

BACKGROUND

Uraemia is accompanied by conditions favouring the rise of H2O2 activity in body fluids. This results from the increased release of H2O2 by polymorphonuclear leukocytes and decreased plasma glutathione peroxidase activity. The purpose of this study was to determine if patients on chronic haemodialysis (HD) exhale more H2O2 than healthy individuals, and if dialysis affects breath H2O2 content.

METHODS

We studied 29 chronic HD patients (mean age 49 +/- 11 years) and 40 healthy persons (mean age 44 +/- 9 years). H2O2, which is volatile, was measured fluorimetrically with the homovanillic acid method in the exhaled breath condensate (EBC) of the study cohort. EBC was collected immediately before and after the HD session and also at 20 and 60 min of HD treatment (n = 14) and once in controls. Peak expiratory flow (PEF), white blood cell (WBC) count, PaO(2) and circulatory cyclic guanosine monophosphate (cGMP), Il-6 and Il-8 concentrations were measured concomitantly. Finally, H2O2 diffusion through the dialyser cuprophane membrane was determined in an in vitro experiment.

RESULTS

At baseline, EBC H2O2 concentration was 22 times higher in HD patients than in controls (2.92 +/- 4.64 vs 0.16 +/- 0.13 microM, P < 0.001). Although the maximum decrease in PEF (431 +/- 52 vs 398 +/- 56 l/min, P < 0.01) and WBC count (6.72 +/- 1.02 vs 3.82 +/- 1.51 x 10(3)/ microl, P < 0.01) occurred at 20 min after the start of HD, no significant changes in breath H2O2 levels were noted throughout the session. Plasma IL-6 and IL-8 levels remained unchanged whereas cGMP rose 1.3 times at 60 min (P < 0.01). In vitro, H2O2 rapidly diffused through the cuprophane membrane.

CONCLUSION

Chronic HD patients exhale more H2O2 than healthy subjects. Although no change of breath H2O2 concentration was observed during HD, as H2O2 easily diffuses through the dialyser membrane, it is not possible to rule out that HD stimulates H2O2 generation.

Effects of uraemia and haemodialysis on neutrophil apoptosis and expression of apoptosis-related proteins

BACKGROUND

In haemodialysis (HD) patients, it is unclear whether increased apoptosis of neutrophils is due to uraemia or HD itself. The purpose of the current study was to assess the effect of uraemia and HD on the rate of apoptosis and apoptosis-related protein expression in whole blood neutrophils.

METHODS

We employed a whole-blood micromethod to test spontaneous apoptosis and expression of apoptosis-regulating proteins in cultured neutrophils from uraemic patients (pre-HD), HD patients and healthy controls. Blood samples were drawn before, after 20 min and after 4 h of haemodialysis, and were then cultured for 20 h. We evaluated the rate of apoptosis from annexin V and propidium iodide staining, and examined bcl-2, Fas/Apo-1 and p53 expression in the cultured neutrophils.

RESULTS

Fas/APO-1 expression and total percentage of apoptotic whole blood neutrophils of pre-HD and HD patients before HD were significantly higher than controls. There was a transient but significant decrease in the percentage of apoptotic neutrophils and Fas/APO-1 expression after 20 min of dialysis. The expression of bcl-2 protein was significantly lower from neutrophils in HD patients compared with controls, and HD significantly downregulated bcl-2 expression. The p53 protein content in HD patients before HD was significantly higher than in pre-HD patients.

CONCLUSIONS

These findings suggest that uraemia accelerates neutrophil apoptosis by increasing Fas/Apo-1, and that HD does not affect neutrophil apoptosis more than uraemia. In addition, HD produces only in a transient sequestration of potentially apoptotic neutrophils.

Antioxidants in the treatment of patients with renal failure

Renal failure is accompanied by oxidative stress, which is caused by enhanced production of reactive oxygen species and impaired antioxidant defense. The suggested therapeutical interventions aimed at reducing oxidative stress in chronic renal failure patients are as follows: 1) the use of biocompatible membranes, ultrapure dialysate, and removal of endogenous foci of infection; 2) haemolipodialysis, and electrolysed reduced water for dialysate preparation; 3) administration of antioxidants (alpha-tocopherol, ascorbic acid, N-acetylcysteine, reduced glutathione); 4) substances possibly affecting oxidative stress indirectly (erythropoietin, sodium selenite). As currently available data have, as yet, provided rather limited evidence for the clinical benefit of antioxidant interventions, at present it is untimely to give practical recommendations with regard to antioxidant treatment of patients with renal failure.

Blood serum and neutrophil L-arginine concentrations and nitric oxide release by neutrophils in chronic uremic patients and healthy persons

BACKGROUND

Plasma levels of L-arginine have previously been evaluated in several studies to reveal either down- or up-regulation of the L-arginine/NO pathway in chronic uremia.

MATERIAL/METHODS

We studied L-arginine plasma levels along with intracellular neutrophil concentration and NO release by peripheral blood neutrophils in patients with chronic uremia.

RESULTS

The L-arginine plasma concentration was found to be significantly higher (64.4 +/- 12.0 micromol/L) in chronic uremic patients (n=25) than in healthy controls (33.0? +/- 10.0 micromol/L; n=25). Neutrophil homogenate L-arginine levels were substantially increased in uremic patients (7.95? +/- 1.10 nmol/10(8) cells) as compared with controls (5.22 +/- 0.46 nmol/10(8) cells). The in vitro release of NO by unstimulated neutrophils was lower in uremic patients (0.14? +/- 0.05? micromol s(-1)) than in healthy persons (0.48 +/- 0.20 micromol s-1). The NO release after uremic neutrophil stimulation with 10(-6) M fMLP was 21.42 +/- 2.13 micromol s(-1), while after PMA it was 31.01 +/- 1.99 micromol s(-1). NO release after normal neutrophil stimulation with 10(-7) M fMLP was 19.52 +/- 2.32 micromol s(-1), and after PMA was 28.63 +/- 3.06 micromol s(-1).

CONCLUSIONS

In chronic uremic patients plasma and neutrophil concentrations of L-arginine were significantly higher. However, there were no significant differences in NO release between normal and uremic neutrophils after stimulation. Our findings may have implications for the impact of the L-arginine-nitric oxide signaling pathway on the pathophysiological changes in the L-arginine: NO pathway seen in chronic uremia.

Left atrial function in patients with renal transplantation

BACKGROUND

Chronic renal failure leads to structural changes and cardiac functional abnormalities known as uremic cardiomyopathy. Eliminating excess water and improving the composition of the inner environment leads to at least partial cardiac function improvement, which is reflected primarily in favorable changes in left ventricular indices. The aim of our study was to evaluate left atrial function in patients after renal transplantation and compare them with clinically healthy subjects.

MATERIAL/METHODS

10 renal transplant patients (2 women, 8 men; mean age 47.8 +/- 6.4 years), treated before transplantation with repeated hemodialysis, were subjected to standard transthoracic echocardiographic examination. Atrial function was evaluated in M-mode and 2D projections and by cross-sectional Doppler echocardiography. The results obtained were compared with 16 healthy controls (9 women, 7 men; mean age 39.7 +/- 9.4 years).

RESULTS

Maximal left atrial dimension (LAmax), left atrial dimension obtained in M-mode of the long axis in parasternal projection (LAa), ejection time (ETlp) and pre-ejection period (PEPlp) were significantly higher in renal transplant patients than in healthy subjects. In both investigated groups there were no differences in minimal left atrial dimensions (LAmin), PEPlp/Etlp ratio, P wave time (P), left atrial fiber shortening fraction (FS%lp), passive evacuate fraction (FBOlp), total left atrial fraction (FClp), or IElp ratio.

CONCLUSIONS

Abnormal function of the left atrium in the course of uremia treated with repeated hemodialysis is not fully corrected after renal transplantation despite the elimination of many cardiovascular complications observed in chronic renal disease.

[Fibrohistiocytic sarcoma of the kidney (borderline malignancy)]

We described a case of 45 year old woman with left kidney tumour. In the pathological examination it appeared asa very seldom neoplasm--fibriohistiocytoma sarcomatosum. This lesion was accidentally diagnosed in ultrasound evaluation due to myomatous uterus observation in gynaecological hospital. There were no signs or symptoms of kidney tumour disease.

Synthesis and immunomodulatory activity of novel analogues of human beta-casein fragment [54-59]

Three novel analogues of human beta-casein fragment [54-59] have been synthesized and tested for their immunomodulatory activity. Interestingly, human beta-casein fragment [54-59] has been found to be increased nitric oxide release from neutrophils. The obtained analogues have shown less immunomodulatory activity than native hexapeptide.

Lipid peroxidation and activities of antioxidant enzymes in the diabetic kidney: effect of treatment with angiotensin convertase inhibitors

Effects of the angiotensin convertase inhibitors captopril (CAP) and enalapril (ENA) on the malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD) and catalase in the kidneys of rats with streptozotocin-induced diabetes were studied. Induction of diabetes resulted in an increase of MDA concentration and progressive decreases of SOD and catalase activities after 6 and 12 weeks. CAP and ENA administration did not affect body weight changes or blood glucose and HbA1c contents in diabetic rats but decreased albuminuria and kidney weight increase, attenuated lipid peroxidation, and prevented the decreases in SOD and catalase activities. These results confirm the oxidative stress in streptozotocin-induced experimental diabetes and point to the beneficial antioxidant effects of angiotensin convertase inhibitors.

Priming effect of met-enkephalin and beta-endorphin on chemiluminescence, chemotaxis and CD11b molecule expression on human neutrophils in vitro

The opioid peptides are widely distributed throughout the body, and they are generated during stress and inflammatory reaction. Opioids are involved in the communication between the immune and neuroendocrine systems. In the present study we have investigated the ability of both met-enkephalin and beta-endorphin to stimulate and prime the human neutrophils for enhanced chemiluminescence (CL) and chemotaxis induced with fMLP, OZ or PMA. We have also tested the effect of beta-endorphin and met-enkephalin on CD11a, CD11b, CD18 and CD16 molecule expression on PMN in vitro. PMN from ten healthy donors were incubated in vitro with different concentrations of beta-endorphin or met-enkephalin, and the CL response was evaluated with luminometer. To assess the effect of opioid peptides on CD11a, CD11b, CD18 and CD16 molecule expression the whole blood samples were incubated with different concentrations of the opioids, then the white cells were labelled with respective PE-conjugated MoAb and evaluated by flow cytometry. We have shown that: (1) met-enkephalin and beta-endorphin at physiological concentrations relevant to that of in vivo (10(-8) and 10(-6) M) enhanced fMLP, PMA or OZ stimulated chemiluminescence and induced chemotactic response, (2) High concentrations of beta-endorphin (10(-3) M) or met-enkephalin (10(-5) M) decreased the CL response of PMN in vitro, (3) The opioid peptides at lower concentrations resulted in CD11b and CD18 molecule up-regulation on neutrophils. We may conclude that opioid peptides in physiological concentration are involved in neutrophil priming whereas in higher concentration exert immunosuppressive potency. Opioid peptides like inflammatory cytokines may prime the neutrophils inflammatory response.

Effect of aminoguanidine on the generation of superoxide anion and nitric oxide by peripheral blood granulocytes of rats with streptozotocin-induced diabetes

The effect of aminoguanidine (AG) on the production of superoxide anion O2*- and nitric oxide (NO) by peripheral blood granulocytes of rats with streptozotocin-induced diabetes was studied. Induction of diabetes resulted in an increase of O2*-. Generation by both unstimulated and opsonized zymosan-stimulated granulocytes was maximal after 6 weeks and lower after 12 weeks. Treatment with aminoguanidine (1 g/l drinking water) decreased O2*- generation after 6 weeks but not after 12 weeks. NO production by both unstimulated and opsonized zymosan-stimulated granulocytes was elevated in diabetic rats to a comparable extent after 6 and 12 weeks. AG attenuated this increased NO production. These results point to the beneficial effect of AG on oxidative stress in experimental diabetes and suggest an antioxidant effect of AG.

Lipid peroxidation and activities of antioxidant enzymes in erythrocytes of patients with non-insulin dependent diabetes with or without diabetic nephropathy

BACKGROUND

Diabetes is known to involve oxidative stress. However, data on oxidative stress in diabetic nephropathy is scant. The aim of this study was to examine lipid peroxidation and activities of key antioxidant enzymes in non-insulin dependent diabetes (NIDDM) without nephropathy and in those with diabetic nephropathy.

METHODS

Twenty-one NIDDM outpatients with obvious diabetic nephropathy (persistent proteinuria, over 0.5 g/day and albumin excretion over 200 microg/min), 14 NIDDM outpatients with a long diabetic history but without hypertension and with normal urinary albumin excretion rate (<20 microg/min) and 19 healthy persons were studied. Malondialdehyde (MDA) content of erythrocytes was quantified by HPLC according to Young et al. In erythrocytes, superoxide dismutase (SOD) activity was determined by the adrenaline method of Misra and Fridovich and catalase was estimated according to Beers and Sizer.

RESULTS

MDA content was significantly elevated in erythrocytes of NIDDM patients without nephropathy vs the control group and even higher in erythrocytes of NIDDM patients with diabetic nephropathy. SOD and catalase activities were lower in erythrocytes of NIDDM patients without nephropathy than in the control group and lowest in erythrocytes of NIDDM patients with nephropathy.

CONCLUSIONS

These results confirm oxidative stress in erythrocytes of NIDDM patients with nephropathy. The intensity of oxidative stress appeared to be greater than in NIDDM patients without nephropathy.

Effect of aminoguanidine on erythrocyte lipid peroxidation and activities of antioxidant enzymes in experimental diabetes

The effect of aminoguanidine (AG) on the malondialdehyde (MDA) concentration and activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in erythrocytes of rats with streptozotocin-induced diabetes was studied. Induction of diabetes resulted in an increase of MDA concentration and decreases of SOD and catalase activities after 6 and 12 weeks. GSH-Px activity increased after 6 weeks and returned to control values after 12 weeks. AG administration did not affect body weight, blood glucose level and HbA1c content in diabetic rats but led to a decrease of MDA concentration and SOD and catalase activities after 12 weeks of treatment, with no significant effect after 6 weeks. AG attenuated the GSH-Px increase after 6 weeks but augmented the activity of this enzyme after 12 weeks. These results confirm the presence of oxidative stress in streptozotocin-induced experimental diabetes and point to the beneficial antioxidant effect of AG.

Effect of aminoguanidine on lipid peroxidation and activities of antioxidant enzymes in the diabetic kidney

The aim of this study was to examine lipid peroxidation and activities of key antioxidant enzymes in kidneys of rats with streptozotocin (STZ)-induced diabetes and the effect of aminoguanidine on diabetes-induced alterations. Three groups, 6 rats each, were studied: control animals, not treated diabetic rats and rats treated with aminoguanidine (AG; 1 g/liter of drinking water). After 6 and 12 weeks the animals were sacrificed and lipid peroxidation products and activities of antioxidant enzymes were determined in their kidney homogenates. Malondialdehyde (MDA) content was significantly elevated and activities of SOD and catalase decreased in the kidneys of STZ-diabetic rats. AG treatment attenuated the increase in MDA content and diminutions of activities of SOD and catalase in the kidneys of diabetic rats. These results confirm oxidative stress in the kidney of rats with STZ diabetes and point to an antioxidant effect of AG in experimental diabetes.

Effect of angiotensin convertase inhibitors on lipid peroxidation and peroxyl radical-trapping capacity in rats with experimental diabetes

Effect of two angiotensin convertase inhibitors, enalapril and captopril, on blood plasma and erythrocyte lipid peroxidation and plasma peroxyl radical-trapping capacity was studied in rats with streptozotocin-induced diabetes. A progressive increase in blood erythrocyte malondialdehyde (MDA) level was observed in diabetic rats after 6 and 12 weeks. Blood plasma MDA level increased while plasma peroxyl radical-trapping capacity was decreased after 12 weeks. Captopril (2 mg/kg body weight) augmented the diabetes-induced changes in MDA content after 6 weeks and prevented them after 12 weeks increasing also the peroxyl radical-trapping capacity. Enalapril (1 mg/kg body weight) counteracted the diabetes-induced changes in MDA content after both 6 and 12 weeks but did not affect the plasma peroxyl radical-trapping capacity. These results suggest a possibility of a therapeutic use of angiotensin convertase inhibitors to attenuate the effects of oxidative stress in diabetes.

[The "Bizzare" leiomyoma in histopathological examination of the uterine myoma: dilemma of the range of operative treatment]

The very rare case of leiomyoma sarcomatosum was presented and differentiated to "bizzare" leiomyoma at 39 years old woman, who was conservative preoperation diagnosis of uterine myoma. To get the after-operation prognosis the following elements of tumour have been studied: mitotic index, presence and type of necrosis, separation of the tumour and perivascular infiltration. A decision of conservative treatment was confirmed by shown world wide literature.

[Function of the left heart atrium during hemodialysis]

In 23 chronic uremic patients effect of four-hour hemodialysis on function the left atrium of the heart was investigated. The reference group consisted of 17 healthy subjects. The function was evaluated by cross-sectional Doppler echocardiography. Before hemodialysis maximal (LAmax) and minimal (LAmin) left atrial dimensions and left atrial dimension obtained in M-mode of long axis in parasternal projection (LAa), pre-ejection period (PEPlp), ejection time (ETlp), PEPlo/ETlp ratio and left atrial fiber shortening fraction (FS%lp) were significantly higher in chronic uremic patients than those found in healthy subjects. Four-hour hemodialysis induced decreases in these indices, but only a lowering of LAa, PEPlp/ETlp ratio was statistically significant in comparison with pre-dialysis period. No correlation was found between changes of the investigated indices of the left atrial function and body weight loss during hemodialysis.

Changes in red blood cell membrane structure in patients with chronic renal failure

The properties of red blood cell membranes in patients with chronic renal failure were investigated using electron paramagnetic resonance spectroscopy. Using spin traps, 5,5-dimethylpirroline-1 oxide and N-tert-butyl-alpha-phenylnitrone, we found generation of hydroxyl radicals in the blood of patients with chronic renal failure after 20 min of regular hemodialysis. The physical state of membrane proteins and membrane osmotic fragility and reductive properties of red blood cells were studied. The increase in the relative correlation time of 4-(2-iodoacetamido)-2,2,6,6-tetramethylpiperidine-1 oxyl indicates the immobilization of membrane protein molecules in erythrocytes of chronic renal failure patients. The decrease in membrane protein mobility was observed in whole blood incubated with tert-butylhydroperoxide, regardless of the presence of iron. We found that the addition of ferrous ions did not aggravate profound changes in membrane proteins induced with tert-butylhydroperoxide. We also demonstrated higher osmotic fragility of erythrocytes in the patients with renal failure as compared to normal subjects. These alterations in membrane structure of red blood cells in hemodialysed patients suggest that hydroxyl radicals generated during hemodialysis can play an important role in the oxidative mechanism of erythrocyte damage.

Myoinositol may be a factor in uremic immune deficiency

In 10 chronic uremic patients on regular hemodialysis treatment and 10 healthy subjects in vitro PHA-induced peripheral blood mononuclear cell (PBMNC) and T-cell enriched lymphocyte proliferative responses were found to be impaired in the presence of myoinositol in the concentration generally observed in the blood serum of chronic uremic patients on regular hemodialysis treatment (600 mumol/l), while it remained unchanged in the presence of myoinositol in the concentration observed in normal blood serum (30 mumol/l). However, both myoinositol concentrations did not affect PMA-induced PBMNC and T-cell enriched lymphocyte proliferative responses, which suggests that inhibitory effect of the high myoinositol concentration on PHA-induced immune cell proliferation is cell membrane-related. In addition, myoinositol (600 mumol/l) significantly depressed CD3, CD4 and HLA-DR antigen expression on PHA-activated PBMNC surface in chronic uremic patients and healthy subjects, while CD8 antigen expression remained unaffected. The results seem to indicate that myoinositol, in the concentrations observed in uremic blood serum, may possibly share the responsibility for uremic immune deficiency.

Nitric oxide release in the peripheral blood during hemodialysis

These studies evaluated the nitric oxide (NO) release in peripheral blood during a four-hour hemodialysis (HD) with single-used cuprophane (CU), polysulfone (PS) and polyacrylonitrile (PAN) membranes in 10 chronic uremic patients. Continuous monitoring of blood NO concentrations was performed with a sterile NO sensor probe inserted vertically into the arterial blood line between the arteriovenous fistula and dialyzer. In the initial period of HD two peaks of blood NO concentrations were observed: the first occurred at the very start of HD and lasted approximately one minute, and the second peaked to a lesser extent at 20 to 26 minutes after the initiation of HD. The extent of NO release was dependent on the type of dialysis membrane used. Areas under curves for blood NO concentrations (in mumol x min) were as follows: CU, 450.8 +/- 163.3; PS, 247.3 +/- 150.6*; PAN, 200.4 +/- 91.0* (*P < 0.05 vs. CU). During the first hour of HD (N = 6) blood NO concentrations were significantly higher at the outlet of CU dialyzer than those found at the inlet. The areas under their curves (in mumol x min) were 169.1 +/- 1.9 and 107.5 +/- 1.6, respectively (P < 0.001). Areas under curves for blood NO concentrations measured for five minutes following a five-minute in vitro incubation of 5 ml heparinized uremic blood samples (N = 10) with dialysis membranes (50 cm2) were as follows (in nmol x min): CU, 2380 +/- 289*; PS, 1293 +/- 45*; PAN, 1117 +/- 37*; control, 502 +/- 56 (*P < 0.05 vs. control). The addition of sodium heparin to uremic blood platelet suspension induced an immediate rise in NO release in a dose-dependent manner, which proved to be a hyperbolic relationship. During HD with CU (N = 6), PS (N = 6) and PAN (N = 6) membranes blood plasma cGMP concentrations significantly increased, particularly at 20 and 60 minutes of the procedure. No significant differences in blood plasma cGMP levels were found between individual dialysis membranes, and no significant correlations were observed between blood plasma cGMP levels and blood NO concentrations. The results indicate that during HD NO is released in the peripheral blood due to blood-membrane and heparin-blood platelet interactions. The extent of intradialytic NO release is dependent on the type of dialysis membrane used (CU > PS approximately PAN).

Changes in red blood cell membrane structure in patients with chronic renal failure

The properties of red blood cell membranes in patients with chronic renal failure were investigated using electron paramagnetic resonance spectroscopy. Using spin traps, 5,5-dimethylpirroline-1 oxide and N-tert-butyl-alpha-phenylnitrone, we found generation of hydroxyl radicals in the blood of patients with chronic renal failure after 20 min of regular hemodialysis. The physical state of membrane proteins and membrane osmotic fragility and reductive properties of red blood cells were studied. The increase in the relative correlation time of 4-(2-iodoacetamido)-2,2,6,6-tetramethylpiperidine-1 oxyl indicates the immobilization of membrane protein molecules in erythrocytes of chronic renal failure patients. The decrease in membrane protein mobility was observed in whole blood incubated with tert-butylhydroperoxide, regardless of the presence of iron. We found that the addition of ferrous ions did not aggravate profound changes in membrane proteins induced with tert-butylhydroperoxide. We also demonstrated higher osmotic fragility of erythrocytes in the patients with renal failure as compared to normal subjects. These alterations in membrane structure of red blood cells in hemodialysed patients suggest that hydroxyl radicals generated during hemodialysis can play an important role in the oxidative mechanism of erythrocyte damage.

The effect of coronary angioplasty on superoxide anion generation and lipid peroxidation. Propriety of pharmacological intervention

In patients with unstable angina pectoris, subjected (n = 20) or not subjected (n = 12) to percutaneous transluminal coronary angioplasty (PTCA), baseline superoxide anion (O.2-) generation by neutrophils in the coronary sinus blood was significantly higher than that found in the basilic vein blood of control healthy subjects (n = 12). During reperfusion following effective PTCA, neutrophil counts in the coronary sinus blood tended to decrease, an effect accompanied by a significant decrease in the neutrophil O.2- generation and enhancement of blood plasma lipid peroxidation as reflected by increased malonyldialdehyde concentrations.

Effect of morphine and naloxone on oxidative metabolism during experimental renal ischemia and reperfusion

During experimental renal ischemia and reperfusion in rabbits, morphine as well as naloxone significantly inhibited the increased superoxide anion (O2-) generation by resting and opsonized zymosan-stimulated phagocytes in renal venous blood. Morphine with naloxone in combination inhibited O2- generation to a lesser extent than that observed when these drugs were used separately. Morphine and/or naloxone did not significantly affect erythrocyte superoxide dismutase (SOD-1), glutathione peroxidase (GPx) and catalase activities or malonyldialdehyde (MDA) concentrations in venous blood during renal ischemia. During reperfusion there was a tendency to a slight reduction of erythrocyte catalase activity in morphine-treated animals, and to slight diminutions of erythrocyte SOD-1 and GPx activities and erythrocyte MDA concentrations in rabbits treated with naloxone and morphine in combination. These results indicate that opioid receptor agonists and antagonists modify the response of the kidney to acute injury. These effects may have relevance to the pattern of oxidative stress seen in patients with acute ischemic renal failure.

[Some indices of peripheral blood oxidative metabolism during acetate and bicarbonate hemodialysis in patients with chronic uremia]

Whole blood superoxide anion generation, erythrocyte superoxide dismutase (SOD-1) and catalase activities and erythrocyte and plasma malonyldialdehyde concentrations were evaluated during cuprophane hemodialysis using bicarbonate and acetate dialysate. Superoxide anion generation by resting phagocytes was found to be significantly higher during bicarbonate hemodialysis, while its generation by opsonized zymosan--stimulated phagocytes did not differ between hemodialyses with both kinds of dialysates. Changes in the erythrocytes SOD-1 activities, found in the initial period of hemodialysis, were independent of the kind of dialysate, while erythrocyte catalase activity was higher during acetate hemodialysis in comparison with bicarbonate one. The kind of dialysate did not affect extent of erythrocyte membrane lipid peroxidation, while plasma lipid peroxidation was lower during acetate hemodialysis in comparison with bicarbonate one. In vitro studies with blood cells incubated with acetate or bicarbonate ions in concentrations, which are observed in vivo during hemodialysis, suggest that probably these ions do not directly affect superoxide anions generation, erythrocyte SOD-1 and catalase activities and erythrocyte membrane lipid peroxidation.

[Hepatocholangiocarcinoma]

In a 48-year-old man, using imaging methods, the presence was shown of a tumour in the right hepatic lobe. The serum AFP and DCP concentrations--the serological markers of hepatocellular cancer--were significantly increased, however, the histological examination of liver biopsy specimen demonstrated the structure of a cancer originating from the bile canaliculi. The material for study obtained during laparotomy and autopsy made possible the demonstration of the structure typical of both cholangiocellular carcinoma and hepatocellular carcinoma in separate foci. The mixed form of hepatocholangiocellular carcinoma is extremely rare and difficult for diagnosis which induced us to report own case.

[A rare case of metastasis of Hodgkin's disease to the spinal cord]

A rare case of Hodgkin's lymphoma metastasis to the spinal cord is reported. The first signs of the metastasis appeared in the 6th year of cytostatic treatment. Diagnostic difficulties hampered causative treatment.

[Generation of active oxygen compounds by whole blood granulocytes in patients with chronic renal failure]

In patients with chronic renal failure (crf) on conservative treatment whole blood granulocyte superoxide anion (O2-) generation was significantly decreased. Regular hemodialysis treatment did not induce its significant improvement. As granulocyte O2- generation determines production of other active oxygen compounds, this phenomenon may lead to the impairment of phagocyte bactericidal activity and increased susceptibility to infections in crf. Various methods of determination of active oxygen compounds give incomparable results.

Whole blood superoxide anion generation and efficiency of some erythrocyte antioxidant systems during recombinant human erythropoietin therapy of uremic anemia

Six chronic uremic patients on regular hemodialysis treatment were given recombinant human erythropoietin (r-huEPO) in a dose of 50 U/kg of body weight intravenously thrice weekly for 14 weeks. Following r-huEPO therapy, unstimulated whole blood superoxide anion (O2) generation did not change significantly, while opsonized zymosan-stimulated whole blood O2 generation increased. At the same time, erythrocyte superoxide dismutase and, in particular, glutathione peroxidase activities were found to be reducing with concomitant lowering of erythrocyte malonyldialdehyde (MDA) concentrations and increase in plasma MDA concentrations.

Modification of some lymphocyte functions in vitro by opioid receptor agonists and antagonist in chronic uremic patients and healthy subjects

In ten chronic uremic patients on regular hemodialysis treatment in vitro experiments revealed that stimulation of opioid receptors with morphine did not significantly change the mitogen-induced proliferative response of peripheral blood lymphocytes and interleukin-2 (IL-2) receptor expression on PHA-stimulated lymphocytes, while it appreciably decreased surface transferrin (Trf) receptor expression on PHA-stimulated lymphocytes. However, metenkephalin inhibited mitogen-induced proliferation and surface Trf receptor expression on uremic lymphocytes without affecting IL-2 receptor expression on PHA-stimulated cells. In ten healthy subjects opioid receptor agonists did not significantly affect mitogen-induced proliferation of lymphocytes, except for the inhibitory effect of 10(-8) M morphine in relation to lymphocytes stimulated with an optimal pokeweed mitogen (PWM) concentration. At the same time, opioid receptor agonists depressed surface IL-2 and Trf receptor expression on PHA-stimulated normal lymphocytes. In most of our experiments naloxone itself, a non-selective competitive opioid receptor antagonist, decreased mitogen-induced lymphocyte proliferation and IL-2 and Trf receptor expression on PHA-stimulated lymphocytes. Moreover, most frequently naloxone did not reverse inhibitory effects of opioid receptor agonists on lymphocytes. The results seem to indicate that opioid receptor stimulation by high metenkephalin concentrations, which are observed in the uremic blood plasma, may share the responsibility for immunodeficiency in chronic uremic patients. Next, in the presence of opioid receptor agonists directions of changes in the mitogen-induced proliferative response may not follow the alterations of IL-2 and Trf receptor expression on both uremic and normal lymphocytes. Finally the results also suggest that naloxone may possibly exert effects which are independent of its action on opioid receptors on lymphocytes.

Superoxide anion generation and lipid peroxidation processes during hemodialysis with reused cuprophan dialyzers

In 11 chronic uremic patients superoxide anion (O2-.) generation and lipid peroxidation processes were determined during hemodialyses with cuprophan dialyzers used three times. Intradialytic changes observed during the first 20 min of hemodialysis, that is the period of the most marked alterations, with consecutive uses of the same dialyzer included: decreased whole blood O2-. generation at rest and following stimulation with opsonized zymosan, decreased reductions in the erythrocyte superoxide dismutase (SOD-1) activity, increased reductions in the plasma malonyldialdehyde (MDA) concentrations, and unchanged erythrocyte MDA concentrations. However, immediately before hemodialysis with third-used dialyzer whole blood O2-. generation at rest and following opsonized-zymosan stimulation, and erythrocyte SOD-1 activity were slightly, but statistically significantly, lower (p less than 0.05), while plasma MDA concentrations were higher (p less than 0.05) than those before hemodialysis with first-used dialyzer; erythrocyte MDA concentrations remained unchanged. The results seem to indicate that dialyzer reuse may exert beneficial effects on whole blood O2-. generation and protect erythrocyte membrane lipids from peroxidation, but, however, it leads to slightly increasing predialysis plasma lipid peroxidation.

Hemodialysis and the acute-phase response in chronic uremic patients

In comparison with healthy persons, chronic uremic patients on regular hemodialysis treatment had significantly higher blood serum concentrations of alpha 1-acid glycoprotein, ceruloplasmin and C4 complement component, while levels of haptoglobin, C3 and transferrin were lower. Serum alpha 2-macroglobulin and alpha 1-antitrypsin levels were similar in both groups. Hemodialysis with cuprophan membrane induced only slight changes in some of these glycoproteins during a 48-hour follow-up period. Seven hours after termination of hemodialysis slight, but significant, decreases in blood serum transferrin and alpha 1-antitrypsin concentrations were observed. Hemodialysis thus does not seem to induce a conspicuous acute-phase reaction.

Effect of hemodialysis on T lymphocyte subsets, con-A-activated suppressor cell activity, and interleukin-2 receptor expression on lymphocytes in chronic uremic patients

Effect of hemodialysis (HD) on some indices of immune response was studied in nine chronic uremics. Total lymphocyte, OKT4+, and OKT8+ cell numbers significantly decreased during the first 20 min of HD, and they were decreased till the third hour of the procedure, whereas the OKT4+/OKT8+ cell number ratio did not change significantly. Before HD, Con-A--activated suppressor cells exerted a stimulatory action on autologous responder cells measured in two-step culture. During HD, Con-A-activated suppressor cell activity transiently appeared, with its peak at 60 min after the start of HD. It was accompanied by a transient rise in lymphocyte count with spontaneous interleukin-2 (IL-2) receptor expression, whereas the number of cells expressing IL-2 receptor following phytohemaglutinin (PHA) stimulation was progressively decreased during HD. A significant correlation was found between the increment of Con-A-activated suppressor cell activity and the increment of spontaneous IL-2 receptor expression on lymphocytes during one single blood flow through the dialyzer. The results supply further evidence that HD may impose additional disturbances on immune regulation in chronic uremics.

[Effect of hemoperfusion on plasma oxidizing capacity and erythrocyte sensitivity to oxidation in patients with chronic uremia]

An effect of haemoperfusion on plasma oxidizing capacity and erythrocyte sensitivity to oxidation was investigated in patients with the chronic uremia. It was found that plasma oxidizing capacity measured with NTB reduction is more pronounced in patients with the chronic uremia than in normal subjects. Oxidizing capacity of plasma is increased at the beginning of haemoperfusion. This effect is clearly seen during single pass of blood through the column with activated carbon. Erythrocyte sensitivity to oxidation following their suspension in the normal saline with phosphate buffer and measured with ascorbic-cyanate test does not differ significantly in patients with the chronic uremia and healthy subjects and does not change markedly during haemoperfusion.

Superoxide anion generation, erythrocytes superoxide dismutase activity, and lipid peroxidation during hemoperfusion and hemodialysis in chronic uremic patients

In 11 chronic uremic patients superoxide anion generation in whole blood, both without and with opsonized zymosan stimulation, was lower than that in 11 healthy controls, while erythrocyte superoxide dismutase (SOD-1) activity and erythrocyte and plasma malonyldialdehyde (MDA) concentrations were elevated. During hemoperfusion (HP) and hemodialysis (HD) superoxide anion generation transiently significantly increased. Changes in the erythrocyte SOD-1 activity and plasma and erythrocyte MDA concentrations during HP suggested that this procedure exerted beneficial effects on lipid peroxidation. On the other hand, during HD erythrocyte membrane lipid peroxidation seemed to be enhanced even further; this phenomenon took place mainly within the dialyzer and a decrease in the erythrocyte SOD-1 activity seemed to be one of the contributing factors. Results of in vitro experiments with cross-incubation of erythrocytes and blood plasma and incubation of whole blood with cuprophan membrane suggest existence of an SOD-1 activator in the uremic blood plasma, which is possibly eliminated during HD.