Down's syndrome: increased enzymatic antioxidative defense is accompanied by decreased superoxide anion generation in blood

Whole blood leukocytes of DS patients were found to produce less superoxide radical anion than in healthy controls, especially without stimulation with zymosan. This decreased superoxide generation may contribute to the immune system deficiency reported for DS.

[Estimation of plasma malonyl dialdehyde concentration in patients with pulmonary tuberculosis]

Plasma malonyl dialdehyde (MDA) concentration was determined by Placer method in patients with pulmonary tuberculosis before and during treatment period with tuberculostatic drugs. Patients were divided into three groups. Group I comprised 20 patients (10 men and 10 women) aged 24-74 years (mean 48.3 years) with pulmonary tuberculosis BK(+). Group II comprised 20 patients (15 men and 5 women) aged 19-67 years (mean 45.1 years) with pulmonary tuberculosis BK(0). The control group consisted of 16 clinically healthy persons (12 men and 4 women) aged 28-59 years (mean 42.5 years). In patients blood samples (5 ml) were collected for examination from cubital vein before, after 1-month and 2-month treatment period with tuberculostatic drugs. In the control group blood samples were collected from cubital vein once. Results of our study showed that plasma MDA concentrations in patients with pulmonary tuberculosis, both before and during treatment period with tuberculostatic drugs, were significantly higher, in comparison to the control group.

[Generation of reactive oxygen species by peripheral blood neutrophils in patients with pulmonary tuberculosis]

Oxygen metabolism of neutrophils was measured using chemiluminescence method in patient with pulmonary tuberculosis. Patients were included into three groups. Group I--20 patients (10 men, 10 women) aged 24-74 years (mean 48.3 years) with pulmonary tuberculosis BK(+). Group II--20 patients (15 men, 5 women) aged 19-67 years (mean 45.1 years) with pulmonary tuberculosis BK(0). The control group consisted 16 clinically healthy persons (12 men, 4 women) aged 28-59 years (mean 42.5 years). Blood samples (5 ml) were collected for examination from cubital vein early morning before breakfast. A luminometer 1251 coupled with an IBM PC AT compatible computer was used for the measurement of chemiluminescence. The chemiluminescence of non-stimulated neutrophils and those stimulated by a receptor stimulus formyl-Met-Leu-Phe (fMLP) as well as an extrareceptor stimulus phorbol myristate acete (PMA) was measured. The results of our study demonstrated that chemiluminescence of non-stimulated as well as stimulated by fMLP and PMA neutrophils was lower in comparison to the values of chemiluminescence in the control group.

[Assessment of nitric oxide level in aqueous humor under physiological conditions and after lens extraction and artificial foldable acrylic lens implantation during experimental work in rabbits]

PURPOSE

To evaluate the presence of nitric oxide (NO) and its level in the aqueous humor of rabbit's eye physiological conditions and after phacoemulsification and acrylic foldable artificial lens implantation. We also investigated nitric oxide maintenance during early postoperative period (between 1-5 days after surgery).

MATERIAL AND METHODS

We examined 30 rabbits (weighing 3.0-3.5 kg) Just before surgery samples of aqueous humor were aspirated. Lens was extracted with phacoemulsification technique. In 15 eyes acrylic foldable IOL (group III) was implanted and 15 eyes were left aphakic (group IV). The aqueous samples were collected on 1, 3, 5 days after surgery. Nitric oxide in each sample was determined with fluorometric assay.

RESULTS

The level of NO in aqueous humor in physiological conditions was estimated to 26.52 nM/dl. After phacoemulsification in both groups the level of nitric oxide was higher than in control group. The day and value of the highest NO level was different among examined groups. The highest level of NO was released during 1st day in group III and on the 3rd day in the group IV.

CONCLUSION

We came to conclusion that the level of nitric oxide in aqueous humor after phacoemulsification in both groups is higher than in control group but significantly lower than in previously examined groups in which the surgery was made with extracapsular technique.

[Assessment of nitric oxide level in aqueous humor under physiological conditions and after lens extraction with PMMA during experimental work in rabbits]

PURPOSE

To evaluate the presence of nitric oxide and measure its level in the aqueous humor of the rabbit's eye, in physiological conditions and after extracapsular lens extraction and PMMA artificial lens implantation. We also investigated nitric oxide maintenance during early postoperative period (between 1-5 day after surgery).

MATERIAL AND METHODS

We used 30 rabbits (weighing 3.0-3.5 kg) Just before surgery samples of aqueous humor were aspirated by anterior chamber puncture. Lens was extracted with extracapsular (envelope) technique. In 15 eyes PMMA IOL was implanted in the bag and 15 eyes were left aphakic. The aqueous samples were collected on 1st, 3rd, 5th days after surgery. Nitric oxide in each sample was measured with respect to fluorometric assay.

RESULTS

In aqueous humor in physiological conditions we detected nitric oxide. Its level was estimated on the value of 26.52 nM/dl. After extracapsular lens extraction in both groups the level of nitric oxide was significantly higher than in control group. The day and value of NO level was different among examined groups. Nitric oxide level diminished significantly on 5th postoperative day.

CONCLUSION

We came to conclusion that after ECCE and PMMA IOL implantation NO level was significantly higher as compared with control. This higher NO level after lens extraction can be responsible for the blood aqueous breakdown.

[Evaluation of oxygen free radical generation and antioxidative enzymatic activity in blood of patients with carcinoma of the larynx (preliminary report)]

The aim of the study were the evaluation of generation of oxygen free radical and antioxidative enzymatic activity in blood of patients with carcinoma of larynx (7 persons, aged 48-68) in comparison with healthy persons (15, aged 21-28). The superoxide anion generation of blood granulocytes described by the rate of the reducted cytochrom C at rest and after stimulation with opsonized zymosan according to Bellavite et al. were measured. The enzymatic activity of superoxide dismutase in blood (method of Misra and Fridovich), catalase (method of Beers and Sizer) and malonyl dialdehyde (method of Placer et al.). The obtained data pointed at the growth of generation of oxygen free radical in blood (at rest and after stimulation with opsonized zymosan) of patients with carcinoma of larynx in comparison with the healthy ones. At the same patients with carcinoma of larynx observed at significant reduction of antioxidative enzymatic activity against the oxygen species generation in blood and significant growth of peroxidation lipids and disturbances of function of cells the human body.

[Antioxidant enzymatic activity in blood of patients with chronic hypertrophy of the maxillary sinuses and larynx and the carcinoma of the larynx]

The aim of the work was the examinations of antioxidant enzymatic activity in blood of patients with chronic hypertrophic of maxillary sinusitis (15 patients) and laryngitis (10 patients), and carcinoma of larynx (7 patients) in comparison with healthy persons (15). The enzymatic activity of superoxide dismutase in blood (method of Misra and Fridovich), katalase (method of Beers and Sizer) and malonyl dialdehyde (method of Placer) were evaluated. The obtained results pointed at significant reduction of antioxidant enzymatic activity against the oxygen species generation in blood of patients with chronic hypertrophic of maxillary sinusits and laryngitis and mainly with the carcinoma of larynx (in comparison with healthy persons). At the same patients observed the significant growth of peroxydation lipoid and disturbances of function of cells the human body.

X-ray and 13C solid-state NMR studies of N-benzoyl-phenylalanine

A crystalline sample of N-benzoyl-DL-phenylalanine 1 and a polycrystalline sample of N-benzoyl-L-phenylalanine 2 were studied using 13C high-resolution solid-state NMR spectroscopy. The X-ray structure of the DL form was established. Sample 1 crystallizes in a monoclinic form with a P21/c space group, a=11.338(1) A, b=9.185(1) A, c=14.096(2) A, beta=107.53(3) degrees, V=1400(3) A3, Z=4 and R=0.053. The principal elements of the 13C chemical shift tensors deltaii for 1 and 2, selectively 13C (99%) labeled at the carboxyl groups were calculated. On the basis of 13C (delta)ii analysis the hydrogen bonding pattern for sample 2 was deduced. Enriched samples were used to establish the intermolecular distance between chemically equivalent nuclei for 1 and spatial proximity in heterogeneous domain for 2, employing the ODESSA pulse sequence. The consistence of the complementary approach covering X-ray data, analysis of the 13C (delta)ii parameters and ODESSA results is revealed.

Moderate systemic hypothermia and cold crystalloid cardioplegia influence on myocardial ischemic and revascularisative injury

The number of granulocytes, their ability to generate superoxide anion (O2-) and the activities of Cu, Zn--superoxide dismutase (SOD-1), glutathione peroxidase (GSH-Px), catalase (CAT) as well as malonyldialdehyde (MDA) concentrations in erythrocytes in the blood extracted from the venous sinus and aorta under coronary artery bypass were examined with the use of St. Thomas Hospital cardioplegic solution. Specimens at the peak of ischemia of the right atrium for ultrastructural examination of the endothelial cells of capillary vessels and sarcomers were taken. The blood was obtained during cardiopulmonary bypass (CPB) before the aorta clamping and immediately after aorta declamping (peak of ischaemia) between 1-3 minute and 10-13 minute of reperfusion. Increase of the number of granulocytes both in the coronary sinus and aortal blood at all examined intervals as well as decrease in the number of ones in sinus compared with aortal blood was noted. The ability to produce superoxide anion radical decreased at the peak of ischemia and during reperfusion. The activity of SOD-1 was lower both after the period of ischemia and reperfusion. The increase in aortal blood activity during reperfusion was characteristic of GSH-Px; the activity was higher in the blood sample from the coronary sinus taken during ischemia and initial reperfusion. With the exception of the initial reperfusion the activity of CAT diminished in all observed cases. MDA concentration did not demonstrate any significant changes with the exception of the initial reperfusion in the aortal blood and later towards the end of reperfusion in the blood from the coronary sinus. Ultrastructural studies indicated overhydration of the cells both in the endothelium and the intercellular space. The obtained data demonstrate that the applied cardioplegic solution protects the myocardium from harmful effects of reactive oxygen species produced as a result of ischemia and reperfusion.

Changes in the structure and properties of corpus vitreous and the preservation of enzymatic composition of rabbit antioxidative system under the influence of sulphur hexafluoride gas

PURPOSE

To evaluate clinical, physiochemical and biochemical changes in rabbit vitreous body caused by local injection of sulphur hexafluoride gas.

MATERIAL AND METHODS

The volume of fluid vitreous fraction was measured with Na+, K+, Mg2+, Ca2+ levels and full proteins concentration in both vitreous fractions in 24 New Zealand rabbits at 2, 7 and 14 day after SF6 injection. The activity of superoxide dismutase, catalase and malonyl dialdehyde were used to evaluate the activity of antioxidative enzymatic system. Control group consisting of 6 New Zealand rabbits had no experimental procedures.

RESULTS

In the investigated group, the fluid vitreous fraction volume was increased while gelatous one was diminished from 0.08 ml in control group to 0.32 ml in the study group (on day 14). The level of Na+, K+, Mg2+, Ca2+ in the fluid fraction was unchanged. On day 7, we noticed statistically significant increase in protein concentration in comparison with the control group and the study group on 14 day. The activity of superoxide dismutase and catalase as well as the level of malonyl dialdehyde were increased in the fluid vitreous fraction compared to the gelatous one in the control group. After the SF6 injection we did not observe any changes of superoxide dismutase and catalase activities in the gelatous part of vitreous body while in the fluid one there was statistically significant decrease in the enzymatic activity and the MDA level in the whole observation time.

CONCLUSIONS

The injected sulphur hexafluoride gas caused the damage of the gelatous vitreous fraction with the increase in the fluid one. The oxygen free radicals might trigger these pathological processes.

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.

[Changes in the antioxidant system of the vitreous in rabbits after administration of sulfur hexafluoride]

PURPOSE

To evaluate the enzymatic activity of antioxidant system of rabbit's vitreous after sulfur hexafluoride (SF6) application.

MATERIAL AND METHODS

Activity of CuZn-SOD, catalase and concentration of MDA in fluid and gel fraction of vitreous were determined in 24 rabbits of New Zealand race on the 2nd, 7th and 14th day after SF6 application. Control group consisted of 6 animals which did not undergo any operations.

RESULTS

Dismutase and catalase activity as well as MDA concentration were higher in fluid fraction than in gel fraction in animals of control group. After SF6 application the activity of enzymes and MDA concentration did not change, whereas in fluid fraction all these values were statistically significantly reduced in all time intervals.

CONCLUSIONS

SF6 leads to disintegration of vitreous structure especially just after its application. Damage to hyalocytes causes dysfunction of enzymatic system. Specific fluid fraction structure and insufficient number of substrates for peroxidation processes are the reasons for simultaneous reduction of MDA concentration.

[Changes in the antioxidant system of the aqueous humor, lens and erythrocytes after sulfur hexafluoride application to the vitreous of rabbits]

AIM

To determine the activity of superoxide dismutase, catalase and the concentration of malondialdehyde (MDA) in aqueous humor, lens and red blood cells after application of sulfur hexafluoride (SF6) into vitreous of rabbits.

MATERIAL AND METHODS

0.5 ml of 100% SF6 was injected into the vitreous of 24 rabbits of New Zealand race. The animals were randomly divided into 3 groups (of 8 rabbits each) depending on the observation day: group 1-2nd day of experiment, group 2-7th day and group 3-14th observation day. The control group (gr. 0) consisted of 6 rabbits that did not undergo any operations. Activity of superoxide dismutase, catalase and MDA concentration were determined in aqueous humor, lens and systemic blood erythrocytes.

RESULTS

On the 7th day of observation an increased activity of dismutase and catalase as well as simultaneous increased MDA concentration were observed. In the lens on the 7th day the increased activity of dismutase was significant in relation to the results in the next time interval, whereas MDA concentration was significantly lower in all time intervals of the experiment in comparison with control group. In erythrocytes an increased activity of catalase was noticed on the 2nd and 14th day.

CONCLUSIONS

Increased occurrence of active oxygen species in aqueous humor leads to insufficiency of the antioxidant system and intensification of peroxidation processes, which is reflected by increased MDA concentration. However, in the lens of this experimental model a slight stimulation of antioxidant system by a small number of free radicals is observed, which provokes a reaction of sweeping them away. Efficiency of lens antioxidant system is secured by weakening of peroxidation processes, which is expressed in minimal drop of MDA concentration.

X-ray and high resolution selenium-77 solid state NMR spectroscopy as complementary probes to structural studies of organophosphorus diselenides

77Se high resolution solid state NMR spectroscopy was employed to study structural properties of bis(diisopropoxyphosphorothioyl) diselenide 1 and bis(dineopentoxyphosphorothioyl) diselenide 2. The principal elements Tii of 77Se effective dipolar/chemical shift tensor were calculated from spinning sideband intensities employing the WIN-MAS program. The values of anisotropy and asymmetry parameters reflect the distortion of the selenium environment. It was found that the T33 component mostly contributes to changes in the isotropic chemical shifts. 77Se CP/MAS experiments were used to decide the assignment of space group by counting the number of crystallographically unique selenium centers in the unit cell. Crystals of diselenide 1 are triclinic, space group P1 with a = 8.485(3) A, b = 8.508(1) A, c = 8.511(2) A, alpha = 98.835(15) degrees, beta = 111.653(24) degrees, gamma = 93.524(21) degrees, V = 559.5(3) A3, Dc = 1.544(2) g/cm3 and Z = 1. Refinement using 2222 reflections for 157 variables gives R = 0.037. Crystals of diselenide 2 are triclinic, space group P1 with a = 9.1418(8) A, b = 9.1465(8) A, c = 9.9200(9) A, alpha = 74.751(8) degrees, beta = 74.629(7) degrees, gamma = 82.216(7) degrees, V = 769.7(1) A3, Dc = 1.365(2) g/cm3 and Z = 1. Refinement using 3316 reflections for 297 variables gives R = 0.0272.

[The generation of oxygen free radicals in blood in patients with hypertrophy of paranasal sinuses and larynx]

The evaluated of oxygen specious generation in blood granulocytes of patients with hypertrophy of paranasal sinuses and larynx. There were 33 patients tested (13 with hypertrophy of paranasal sinuses, 10 with hypertrophy of larynx and 10 healthy). The superoxide anion generation of peripheral blood granulocytes described by the rate of the reduced cytochrome C at rest and after stimulation with opsonized zymosan according to Bellavite were measured. There were statistically significant differences between the superoxide anion generation in patients with hypertrophy of paranasal sinuses and larynx in comparison with the healthy ones.

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).

Effects of cation interactions on sugar anion conformation in complexes of lactobionate and gluconate with calcium, sodium or potassium

In the investigated compounds, the tetrahydrated calcium chloride salt of lactobionic acid (Ca2+.-Cl(-).C12H21O12(-).4H2O), potassium lactobionate (K+.-C12H21O12-), sodium lactobionate monohydrate (Na+.-C12H21O12-.H2O) and calcium galactonate hydrate (Ca2+.2C6H11O7(-).5H2O), the cations and hydrogen-bonding systems have a strong influence on the geometries and conformations of the carbohydrate anions.

[Metabolic changes in blood oxygen in the human heart under ischemic and reperfusion conditions]

The number of granulocytes, their capability to generate O2-. and the activity of SOD-1, GSH-Px, Cat as well as MDA concentrations in erythrocytes in the blood extracted from the venous sinus and aorta under coronary artery bypass with use of St. Thomas cardioplegic solution were determined. The blood for examination was obtained before the institution of cardiopulmonary bypass, in the period of the deepest ischaemia (just after declamping of the aorta) and between the 1-3 minute and the 10-13 minute of reperfusion. A rise in the number of granulocytes both in the venous sinus and aortal blood at all examined intervals was noted. Capability to produce superoxide anion radicals decreased at the peak of ischemia and during reperfusion. The activity of SOD-1 was lower both after the period of ischemia and reperfusion. A rise in aortal blood activity during reperfusion was characteristic for GSH-Px; the activity was greater in the blood sampled from the coronary sinus during ischemia and initial reperfusion. With the exception of the initial reperfusion the activity of Cat diminished in all observed cases. We did not observe any significant changes in MDA concentration with the exception of the initial reperfusion in the aortal blood and later during reperfusion in the blood from the coronary sinus. The results demonstrate that the applied cardioplegic solution may protect myocardium from harmful effects of active oxygen froms produced as a results of ischemia and reperfusion.

Sex and strain differences of acoustic startle reaction development in adolescent albino Wistar and hooded rats

Acoustic startle responses (ASR) were studied in 12 young Wistar albino and in 15 hooded rats of both genders. The six week old animals were first exposed to a 6.9 kHz tone pair of 2 ms pulses of 120 db intensity with the inter-stimulus interval (ISI) between 2 and 11 ms. ASR amplitudes and latencies as a function of the ISI, animal strain and gender were recorded and analyzed for ten consecutive weeks. No differences in the ASR amplitude between Wistar and hooded rats were found. ASR amplitude increased during the experimental period and followed body weight increase. Significant differences were also observed between male and female rats in their startle responses to acoustic stimuli. Generally, male subjects responded with a greater ASR amplitude than females, and the changes may be attributed to the difference in neuromuscular development between genders. This experiment sets a background for further developmental studies.

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.

[Influence of percutaneous transluminal coronary angioplasty (PTCA) on superoxide anion generation by whole blood granulocytes in patients with unstable angina pectoris (part I)]

In twenty patients with unstable angina, the effects of percutaneous transluminal coronary angioplasty (PTCA) on superoxide anion generation by neutrophils (PMNs) obtained from ulnar vein (UV) and coronary sinus (CS) were investigated. Blood samples for the investigations were taken from CS just before the procedure, within the first minute after the last balloon inflation and 20 minutes after PTCA; from BV--just before the procedure and 20 minutes following it. The results were compared with those obtained from 12 patients with unstable angina, (in whom coronary angiography was performed, but for various reasons angioplasty was desisted from) and with those obtained from 20 clinically healthy persons. In patients with unstable angina, the significantly increased O2.- generation by PMNs from CS and BV was found at rest as well as following opsonized-zymosan stimulation, compared with healthy persons. Within the first minute after PTCA, the significantly decreased O2.- generation by PMNs from CS was observed, compared with the results before the procedure (rest.--11.29 +/- 0.73 and 10.15 +/- 0.65 nmol/cell/min., p < 0.05; stimulation--27.62 +/- 6.25 and 18.54 +/- 3.37 nmol/cell/min., p < 0.05). Twenty minutes after PTCA O2.- generation by PMNs from CS still decreased (rest--9.23 +/- 1.08 nmol/cell/min., stimulation--15.71 +/- 5.98 nmol/cell/min.). In blood samples taken from BV before and after PTCA, no statistically significant differences in O2.- generation were observed (rest--11.32 +/- 0.79 nmol/cell/min. and 10.77 +/- 1.43 nmol/cell/min.; stimulation--25.96 +/- 6.12 nmol/cell/min. and 21.15 +/- 5.47 nmol/cell/min.).

[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.

[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.

[Production of superoxide free radicals by peripheral blood leukocytes in patients with psoriasis treated by the Re-PUVA-C method]

The investigations were carried out in 20 patients with severe forms of psoriasis, and in 18 healthy subjects. The generation of free superoxide radicals by polymorphonuclear leukocytes of peripheral blood was evaluated by Bellavite et al. (1983) method by use superoxide dismutase of Sigma firm. The obtained results may confirm alterations in PMNL functions in patients with psoriasis observed by many authors. It may confirm the probability of damage of membrane structures and alterations in their bactericidal functions.

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.

Adenine nucleotides and 2,3-dophosphoglycerate in the erythrocytes during physical exercise and restitution in healthy subjects

The reported investigations were carried out in 6 young (20 years old) healthy males who performed a 10-minute exercise on a Monark cycle ergometer at workloads increasing the heart rate to 170/minute. Before the exercise, after its termination, and after 30 minutes of restitution the concentrations of adenosine-5' triphosphate, adenosine-5' diphosphate, adenosine-5' monophosphate, 2,3-diphosphoglycerate, nicotinamide-adenine dinucleotide and nicotinamide-adenine dinucleotide phosphate were assayed in erythrocytes. After the end of exercise a non-significant increase in ATP concentration and a non-significant decrease of 2,3-DPG were found in the erythrocytes. The concentrations of ADP and AMP were lower than at rest, both, after the end of exercise and after 30 minutes of restitution (p less than 0.05). The concentrations of nicotinamide-adenine dinucleotide and nicotinamide-adenine dinucleotide phosphate decreased after exercise (p less than 0.05) fell even more after 30 minutes of restitution (p less than 0.05).

[Effect of zinc ions on the selected osmotic characteristics of human erythrocytes in vitro (author's transl)]

Effect of zinc on the osmotic fragility-stability of human erythrocytes in hypotonic NaCl solutions and on the reversion of hemolysis was studied in vitro. Erythrocytes washed in 0.9% NaCl were incubated in 1.5 X 10(-3) M ZnSO4 solution in 0.6% NaCl. The obtained results indicate an osmotic stabilization of the erythrocyte membrane by Zn2+ ions increase in osmotic fragility-stability in hypotonic NaCl solutions and increase in reversion of hemolysis due to the effect of Zn2+ ions. As the process of stabilization of the erythrocyte membrane by zinc ions was found to be independent of temperature, a non-enzymatic character of this phenomenon is postulated on this basis and on the basis of literature data.