Preliminary evaluation of selected inflammatory cytokine gene expression in lymphocytes isolated from whole human blood infected with trans-anethole-treated Staphylococcus aureus Newman strain.

In our previous study based on a whole-blood model of sepsis infected with trans-anethole (TA)-treated Staphylococcus aureus, we have found that innate immune response was more effective in comparison to non-treated cells. Due to the previous observation, in the current preliminary study, a primary adaptive immune response was analysed. This study was conducted to evaluate the expression of selected cytokine (IL1B, IL2, IL6, IL10, TNF, TGFB1, IFNG) and Toll-like receptor (TLR2) genes in lymphocytes isolated from whole human blood infected with S. aureus Newman strain treated with TA. The lymphocytes were isolated by density gradient centrifugation from blood samples infected with S. aureus, as well as from non-infected samples. Gene expression was measured using quantitative real-time PCR. The lymphocytes isolated from the blood infected with TA-treated staphylococcal cells demonstrated significantly greater IL10, IL1B, IL6, TNF and TLR2 expression. Hence, it is possible that the previously observed changes in the surface structure of TA-treated S. aureus Newman strain may significantly increase the relative expression of IL10, IL1B, IL6, TNF and TLR2 genes in lymphocytes; however, further studies are needed.

The activation of complement system in different types of renal replacement therapy.

The complement cascade is a part of innate immune system that responds rapidly to defend the host against invading microorganisms and complete the action of immune cells. The activation of the complement system leads to increased inflammatory response, fibrosis of tubulointestinal tissue and progression of chronic kidney disease (CKD). The purpose of this study was to determine whether the type of renal replacement therapy has an effect on activation of the complement system. The study included 79 patients with CKD stages 4 - 5 according to Kidney Disease Improving Global Outcomes (KDIGO) guidelines on conservative treatment (CKD4-5) (n = 28), on peritoneal dialysis (PD) (n = 21) and undergoing chronic haemodialysis (HD) (n = 30). The concentrations of complement components C3a, C5a and C5b-9 were determined in plasma using the ELISA method. The highest concentration of C3a was found in PD group and differed significantly from HD group, both before and after haemodialysis treatment and CKD4-5 patients (P = 0.00001). The C5a concentration in HD patients was significantly higher than in PD patients and CKD4-5 group (P = 0.0001). The C5a and C5b-9 concentrations significantly increased during the haemodialysis session (P = 0.027 and P = 0.01, respectively). The values of C5b-9 observed in PD and CKD4-5 groups were significantly lower, than in HD patients (P = 0.0005). In HD patients the negative correlations were found between the time of haemodialysis treatment and C5b-9 concentration, both before and after haemodialysis session (Rs = -0.436, P = 0.016 and Rs = -0.365, P = 0.046, respectively). The type of renal replacement therapy influences the complement activation, which is the most intense during the haemodialysis treatment and correlates negatively with the haemodialysis vintage. The promising therapeutic intervention may be an improvement of HD biocompatibility.

Bone Metabolism Parameters in Hemodialysis Patients With Chronic Kidney Disease and in Patients After Kidney Transplantation.

Chronic kidney disease adversely affects the structure and metabolism of bone tissue, which may be a result of disturbed biochemical processes in adipose tissue. Renal replacement therapy is a life-saving therapy but it does not restore all metabolic functions and sometimes even escalates some disturbances. The study included 126 subjects: 47 hemodialysis patients (HD), 56 patients after renal transplantation (Tx) and 23 healthy controls (K). Bone density at the femoral neck (FN) and lumbar spine (LS), as well as body composition (adipose tissue content and lean body mass) were measured in each patient using the DXA method. In addition, serum concentrations of glucose, calcium, phosphorus, parathormone, FGF23, Klotho, osteocalcin, leptin, adiponectin and 1,25-dihydroxyvitamin D3 were measured. We observed significantly higher concentrations of leptin, FGF23 and Klotho proteins in the HD patients (77.2±48.1 ng/ml, 54.7±12.4 pg/ml, 420.6±303.8 ng/ml, respectively) and the Tx group (33.2±26.5 ng/ml; 179.8±383.9 pg/ml; 585.4±565.7, respectively) compared to the control group (24.4±24.6 ng/ml, 43.3±37.3 pg/ml, 280.5±376.0 ng/ml). Significantly lower bone density at FN was observed in the HD and Tx patients in comparison to the controls and in the HD patients compared to the Tx group. There were no significant differences in body mass composition between the studied groups. The results of this study indicate that both hemodialysis and transplantation are associated with increased serum concentrations of leptin, FGF23 and Klotho proteins, as well as lower bone density at femoral neck.

Bioactive Sphingolipids, Complement Cascade, and Free Hemoglobin Levels in Stable Coronary Artery Disease and Acute Myocardial Infarction.

BACKGROUND: Acute myocardial infarction (AMI) and coronary artery bypass graft (CABG) surgery are associated with a pathogen-free inflammatory response (sterile inflammation). Complement cascade (CC) and bioactive sphingolipids (BS) are postulated to be involved in this process. AIM: The aim of this study was to evaluate plasma levels of CC cleavage fragments (C3a, C5a, and C5b9), sphingosine (SP), sphingosine-1-phosphate (S1P), and free hemoglobin (fHb) in AMI patients treated with primary percutaneous coronary intervention (pPCI) and stable coronary artery disease (SCAD) undergoing CABG. PATIENTS AND METHODS: The study enrolled 37 subjects (27 male) including 22 AMI patients, 7 CABG patients, and 8 healthy individuals as the control group (CTRL). In the AMI group, blood samples were collected at 5 time points (admission to hospital, 6, 12, 24, and 48 hours post pPCI) and 4 time points in the CABG group (6, 12, 24, and 48 hours post operation). SP and S1P concentrations were measured by high-performance liquid chromatography (HPLC). Analysis of C3a, C5a, and C5b9 levels was carried out using high-sensitivity ELISA and free hemoglobin by spectrophotometry. RESULTS: The plasma levels of CC cleavage fragments (C3a and C5b9) were significantly higher, while those of SP and S1P were lower in patients undergoing CABG surgery in comparison to the AMI group. In both groups, levels of CC factors showed no significant changes within 48 hours of follow-up. Conversely, SP and S1P levels gradually decreased throughout 48 hours in the AMI group but remained stable after CABG. Moreover, the fHb concentration was significantly higher after 24 and 48 hours post pPCI compared to the corresponding postoperative time points. Additionally, the fHb concentrations increased between 12 and 48 hours after PCI in patients with AMI. CONCLUSIONS: Inflammatory response after AMI and CABG differed regarding the release of sphingolipids, free hemoglobin, and complement cascade cleavage fragments.

The effect of low levels of lead (Pb) in the blood on levels of sphingosine-1-phosphate (S1P) and expression of S1P receptor 1 in the brain of the rat in the perinatal period.

Sphingolipids are the main components of the lipid membrane. They also perform structural functions and participate in many signal transmission processes. One of the bioactive sphingolipids is sphingosine-1-phosphate (S1P), a ligand for five G protein-coupled receptors (S1PRs1-5), which can also act as an intracellular second messenger. S1P is responsible for the stimulation of progenitor cells in the brain, but it can also induce apoptosis of mature neurons. This study is aimed at assessing the effect of pre- and neonatal exposure to permissible Pb concentrations on S1P levels and S1PR1 (EDG1) expression in the prefrontal cortex, cerebellum, and hippocampus of rats. The concentrations of S1P were determined by RP-HPLC, S1PR1 expression was determined by RT PCR and Western Blot, and receptor immunolocalization was determined by immunohistochemistry method. Our results showed that even low blood Pb concentrations, i.e. within the acceptable limit of 10 µg/dL caused changes in the concentration of S1P in the cerebellum, prefrontal cortex, and hippocampus. Our data also showed a significant decrease in the level of S1PR1 in all studied part of brain, without significant changes in S1PR1 gene expression. Pre- and neonatal exposure to Pb also resulted in a decrease in the expression of S1PR1 in glial cells in all regions of the Cornu Ammonis (CA1-CA4) and Dentate Gyrus in the hippocampus, as well as in all layers of the cerebellum and prefrontal cortex, compared to the unexposed control group.

Uridine--an indicator of post-exercise uric acid concentration and blood pressure.

Studies have shown that uridine concentration in plasma may be an indicator of uric acid production in patients with gout. It has been also postulated that uridine takes part in blood pressure regulation. Since physical exercise is an effective tool in treatment and prevention of cardio-vascular diseases that are often accompanied by hyperuricemia and hypertension, it seemed advisable to attempt to evaluate the relationship between oxypurine concentrations (Hyp, Xan and UA) and that of Urd and BP after physical exercise in healthy subjects. Sixty healthy men (17.2+/-1.71 years, BMI 23.2+/-2.31 kg m(-2), VO(2max) 54.7+/-6.48 ml kg(-1) min(-1)) took part in the study. The subjects performed a single maximal physical exercise on a bicycle ergometer. Blood for analyses was sampled three times: immediately before exercise, immediately after exercise, and in the 30th min of rest. Concentrations of uridine and hypoxanthine, xanthine and uric acid were determined in whole blood using high-performance liquid chromatography. We have shown in this study that the maximal exercise-induced increase of uridine concentration correlates with the post-exercise increase of uric acid concentration and systolic blood pressure. The results of our study show a relationship between uridine concentration in blood and uric acid concentration and blood pressure. We have been the first to demonstrate that a maximal exercise-induced increase in uridine concentration is correlated with the post-exercise and recovery-continued increase of uric acid concentration in healthy subjects. Thus, it appears that uridine may be an indicator of post-exercise hyperuricemia and blood pressure.

Novel evidence that crosstalk between the complement, coagulation and fibrinolysis proteolytic cascades is involved in mobilization of hematopoietic stem/progenitor cells (HSPCs).

The role of blood proteinases in the mobilization of hematopoietic stem/progenitor cells (HSPCs) is still not well understood. As previously reported, activation of the complement cascade (ComC) and cleavage of C5 by C5 convertase are enabling events in the release of C5a that plays a crucial role in the egress of HSPCs from bone marrow (BM) into peripheral blood (PB) and explains why C5-deficient mice are poor mobilizers. Here we provide evidence that during granulocyte colony-stimulating factor- and AMD3100-induced mobilization, not only the ComC but also two other evolutionarily ancient proteolytic enzyme cascades, the coagulation cascade (CoaC) and the fibrynolytic cascade (FibC), become activated. Activation of all three cascades was measured by generation of C5a, decrease in prothrombin time and activated partial thromboplastin time as well as an increase in the concentrations of plasmin/antiplasmin and thrombin/antithrombin. More importantly, the CoaC and FibC, by generating thrombin and plasmin, respectively, provide C5 convertase activity, explaining why mobilization of HSPCs in C3-deficient mice, which do not generate ComC-generated C5a convertase, is not impaired. Our observations shed more light on how the CoaC and FibC modulate stem cell mobilization and may lead to the development of more efficient mobilization strategies in poor mobilizers. Furthermore, as it is known that all these cascades are activated in all the situations in which HSPCs are mobilized from BM into PB (for example, infections, tissue/organ damage or strenuous exercise) and show a circadian rhythm of activation, they must be involved in both stress-induced and circadian changes in HSPC trafficking in PB.

Clinical analysis of systemic and adipose tissue levels of selected hormones/adipokines and stromal-derived factor-1.

Recent studies demonstrated that selected hormones/adipokines may be involved into the regulation of bone metabolism and bone marrow-derived hematopoietic stem/progenitor cells (HSPCs) mobilization in humans. Interestingly, in obese individuals significantly higher numbers of spontaneously circulating stem cells are also observed. Therefore in this study we comprehensively examined plasma and AT (subcutaneous and visceral/omental) levels of hormones/adipokines involved in HSPCs mobilization in lean, overweight and obese individuals as well as verified their potential associations with concentrations of HSPCs chemoattractant, stromal-derived factor-1 (SDF-1). Blood and AT samples (35 subcutaneous and 35 omental) were obtained from individuals undergoing elective surgery. Plasma and AT-derived interstitial fluid levels of resistin, visfatin, osteocalcin and SDF-1 were measured using ELISA. In our study obese patients had almost significantly (P<0.06) higher plasma visfatin and resistin levels as well as lower osteocalcin concentrations (P<0.04) than lean individuals. Osteocalcin and resistin concentrations were strongly associated with levels of SDF-1 and metalloproteinases (MMP 2 and 9). AT levels of all examined substances were significantly lower than the corresponding levels in the plasma (in all cases at least P<0.05), and depot-specific differences in the concentrations of these factors were found only in terms of osteocalcin and SDF-1. In addition, subcutaneous and visceral/omental concentrations of osteocalcin and visfatin, but not of resistin, were associated with values of such parameters as age, body mass or adiposity indexes (BMI and BAI, respectively) and/or waist-to-hip ratio (WHR). In summary, our study showed that in obese individuals the biochemical constellation of adipokines/hormones involved in the process of HSPCs mobilization resembles this observed during pharmacological HSPCs mobilization. Moreover, our study offers further indirect translational evidence for existence of a biochemical cross-talk between bone and AT metabolism (so called - bone-fat- axis) in humans.

The effect of PGE administration on the activity of oxidative system in erythrocytes and platelets during ischemia reperfusion injury and on postoperative renal function in patients undergoing open abdominal aortic aneurysm reconstruction.

Postoperative decline of renal function remains a common and unpredictable complication after abdominal aortic aneurysm (AAA) reconstruction. The oxidative stress that occurs during perioperative ischemia/reperfusion injury (I/R) may contribute to the development of this complication. In this study, the influence of intraoperative prostaglandin E (alprostadil) administration on erythrocyte and platelet antioxidants as well as postoperative kidney function modulation were verified. AAA patients were randomly divided into control and study/alprostadil groups. Blood samples were collected directly before aortic clamping and 5 min after aortic declamping. Superoxide dismutase, catalase, glutathione, glutathione peroxidase (GPx), and glutathione transferase (GST) were measured using spectrophotometry. During I/R, the activity of catalase (57.14+/-30.65 vs 128.35+/-91.94 U/mg protein; P < 0.009), GPx (0.21+/-0.18 vs 0.35+/-0.21 mU/g protein; P = 0.028), and GST (217.49+/-101.39 vs 310.66+/-88.86 mU/g protein; P = 0.0006) significantly increased in the control group. GST activity before the aortic clamping was significantly lower in the study/alprostadil group (2.84+/-2.28 vs 3.48+/-2.30 U/g Hb; P = 0.05). The activity of the selected antioxidants proved to be of a diagnostic value for predicting postoperative decline in renal function. In conclusion, during I/R after AAA reconstruction, activation of various erythrocyte and platelet antioxidants occurs. Perioperative administration of alprostadil is associated with disruption of this activation.

Spectrophotometric methods as a novel screening approach for analysis of dihydropyrimidine dehydrogenase activity before treatment with 5-fluorouracil chemotherapy.

5-Fluorouracil (5-FU) is one of the most commonly used chemotherapeutics in the treatment of malignancies originating from breast, prostate, ovarian, skin and gastrointestinal tissues. Around 80% of administered dose of 5-FU is catabolized by dihydropirymidine dehydrogenase (DPD). Patients, in whom a deficiency or insufficient activity of this enzyme is observed, are at great risk of development of severe, even lethal, 5-FU toxicity. According to recent studies, so far over 30 mutations of DPYD gene, which are associated with DPD deficiency/insufficiency, have already been discovered. Currently, there are several analytical methods used for measurements of DPD activity. However, in this paper we report a novel, simple, economical and more accessible spectrophotometric method for measurements of DPD activity in the peripheral blood mononuclear cells (PBMCs) that was developed and validated on analysis of 200 generally healthy volunteers aged 22-63. We present two spectrophotometric protocols in this study, and as a reference method we used already described reverse phase high-performance liquid chromatography (RP HPLC) analysis. Basing on our findings, we conclude that spectrophotometric methods may be used as a screening protocol preceding 5-FU-based chemotherapy. Nevertheless, before introduction into clinical reality, our results should be confirmed in further larger studies.

Growth factor content in PRP and their applicability in medicine.

This paper reviews available reports on the advantages and possibilities of clinical use of platelet-rich plasma preparations, with particular emphasis on platelet growth factors. Platelets, an important reservoir of growth factors in the body, play an important role in many processes such as coagulation, immune response, angiogenesis and the healing of damaged tissues. Numerous proteins are contained in the alpha-granules of platelets: platelet-derived growth factor (PDGF), transforming growth factor (TGF), platelet factor interleukin (IL), platelet-derived angiogenesis factor (PDAF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), insulin-like growth factor IGF and fibronectin. The development of methods and systems for blood and cell sorting (e.g. CAPSS - compact advanced platelet sequestration system Elektromedics 500, PCCS - platelet concentrate collection system Curasan) have made it possible to obtain significant concentrations of platelets (even by 338 percent) and high concentrations of growth factors, in a form of sterile mass that can be used immediately for clinical purposes. Platelet-rich plasma (PRP; autologous platelet-rich plasma - APRP) are platelet concentrates made of autogenous blood with a high number of platelets in a small volume of plasma. The clinical efficacy of platelet concentrates depends mainly on the number of platelets and the concentration of their growth factors, which act as transmitters in most processes in tissues, particularly in healing where they are responsible for proliferation, differentiation, chemotaxis and tissue morphogenesis. They operate as part of autocrine, paracrine and endocrine mechanisms. Growth factors derived from centrifuged blood were first used in patients with chronic skin ulcers. The clinical use of PRP for a wide variety of applications has been reported mostly in oral and maxillo-facial surgery, orthopedic surgery, treatment of soft tissue diseases and injuries, treatment of burns, hard-to-heal wounds, tissue engineering and implantology.

Platelet lipidomic.

Lipids account for 16-19 percent dry platelet matter and includes 65 percent phospholipids, 25 percent neutral lipids and about 8 percent glycosphingolipids. The cell membrane that surrounds platelets is a bilayer that contains different types phospholipids symmetrically distributed in resting platelets, such as phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylcholine, and sphingomyelin. The collapse of lipid asymmetry is exposure of phosphatidylserine in the external leaflet of the plasma bilayer, where it is known to serve at least two major functions: providing a platform for development of the blood coagulation cascade and presenting the signal that induces phagocytosis of apoptotic cells. During activation, this asymmetrical distribution becomes disrupted, and PS and PE become exposed on the cell surface. The transbilayer movement of phosphatidylserine is responsible for the platelet procoagulant activity. Exposure of phosphatidylserine is a flag for macrophage recognition and clearance from the circulation. Platelets, stored at room temperature for transfusion for more than 5 days, undergo changes collectively known as platelet storage lesions. Thus, the platelet lipid composition and its possible modifications over time are crucial for efficacy of platelet rich plasma therapy. Moreover, a number of substances derived from lipids are contained into platelets. Eicosanoids are lipid signaling mediators generated by the action of lipoxygenase and include prostaglandins, thromboxane A2, 12-hydroxyeicosatetraenoic acid. Isoprostanes have a chemical structure similar to this of prostanoids, but are differently produced into the particle, and are ligands for prostaglandins receptors, exhibiting biological activity like thromboxane A2. Endocannabinoids are derivatives from arachidonic acid which could reduce local pain. Phospholipids growth factors (sphingolipids, lysophosphatidic acid, platelet-activating factor) are involved in tissue regenerating process. Finally, a warning concerning the atherogenic role of platelets, although it should not be exerted in a local therapy, is mentioned. The lipid content of plaletets must be taken into account when these particles are concentrated and used for a local therapy, while the different categories of lipid derivatives could improve or affect the quality of the product.

Oxidative stress and renal interstitial fibrosis in patients after renal transplantation: current state of knowledge.

Long-term outcomes in renal transplantation has represented a major challenge for transplantologists and nephrologists for many years. The use of a new generation of immunosuppressive drugs has contributed to reducing the incidence of acute rejection episodes, but chronic allograft nephropathy is the cause of renal allograft loss in ∼50% of recipients. Organ fibrosis is the main histopathologic finding in those cases. Many researchers have focused on mechanisms leading to fibrosis. It is thought that an explanation of the pathologic mechanism of this phenomenon may improve long-term effects of therapy for kidney transplant recipients.

Oxidative stress indices in rats under immunosuppression.

Immunosuppressants lead to generation of reactive oxygen species (ROS). Oxidative stress (OxS) can initiate chronic allograft nephropathy (CAN). The most active antioxidant enzymes, superoxide dysmutase (SOD) and catalase (CAT), are present in erythrocytes. Glutathione peroxidase (GPx) is produced in the proximal tubules of nephrons. Malonyldialdehyde (MDA) concentrations are a marker of OxS intensity in plasma. In vitro and animal model studies have shown increased or decreased OxS during treatment with tacrolimus (Tac) or cyclosporine (CyA). Results obtained in humans after solid organ transplantation have been contradictory, because of confounding factors such as ischemia-reperfusion injury, donor and recipient ages, endothelial injury, and comorbidity. The aim of this study was to assess the intensity of OxS among rats under chronic immunosuppression (IS) without a transplantation. We examined 49 male Wistar rats. IS started at 12 weeks of age was continued for 6 months: group I were controls (n=7); group II, Tac+sirolimus (Rapamycin [Rapa])+corticosteroids (CS; n=6); group III, CyA+Rapa+CS (n=4 of which 2 died); group IV, Rapa+mycophenolate mofetil (MMF)+CS (n=6); group V, CyA+MMF+CS (n=6); group VI, CsA+MMF+CS for 3 months followed by conversion to Rapa (n=6); group VII, Tac+MMF+CS (n=6 rats); and group VIII, Tac+MMF+CS for 3 months followed by conversion to Rapa (n=6). The drug doses were as follows: Tac 4 mg/kg/d; MMF 20 mg/kg/d; CyA 5mg/kg/d; Rapa 0.5 mg/kg/d; and CS 4 mg/kg/d. Multiple regression analysis revealed that all IS drugs decreased GPx activity (P<.001) except CS, which increased it (P<.0001). Multiple regression analysis showed that CsA and Tac decreased plasma MDA concentrations (P<.01), whereas CS increased them (P<.05). In conclusion, all IS drugs except CS damage proximal tubules of nephrons.

Adenine, guanine and pyridine nucleotides in blood during physical exercise and restitution in healthy subjects.

Maximal physical exertion is accompanied by increased degradation of purine nucleotides in muscles with the products of purine catabolism accumulating in the plasma. Thanks to membrane transporters, these products remain in an equilibrium between the plasma and red blood cells where they may serve as substrates in salvage reactions, contributing to an increase in the concentrations of purine nucleotides. In this study, we measured the concentrations of adenine nucleotides (ATP, ADP, AMP), inosine nucleotides (IMP), guanine nucleotides (GTP, GDP, GMP), and also pyridine nucleotides (NAD, NADP) in red blood cells immediately after standardized physical effort with increasing intensity, and at the 30th min of rest. We also examined the effect of muscular exercise on adenylate (guanylate) energy charge--AEC (GEC), and on the concentration of nucleosides (guanosine, inosine, adenosine) and hypoxanthine. We have shown in this study that a standardized physical exercise with increasing intensity leads to an increase in IMP concentration in red blood cells immediately after the exercise, which with a significant increase in Hyp concentration in the blood suggests that Hyp was included in the IMP pool. Restitution is accompanied by an increase in the ATP/ADP and ADP/AMP ratios, which indicates an increase in the phosphorylation of AMP and ADP to ATP. Physical effort applied in this study did not lead to changes in the concentrations of guanine and pyridine nucleotides in red blood cells.

Inhibition of erythrocyte phosphoribosyltransferases (APRT and HPRT) by Pb2+: a potential mechanism of lead toxicity.

Many reports show that red blood cells of people exposed to lead have a decreased ATP concentration, decreased adenylate energy charge value and many metabolic and morphological abnormalities. Since the synthesis of nucleotides in erythrocytes occurs only through salvage pathways, we hypothesized that a decrease in nucleotide concentrations may be caused by lead-induced inhibition of erythrocyte phosphoribosyltransferases: adenine APRT (EC 2.4.2.7) and hypoxanthine-guanine HPRT (EC 2.4.2.8). These enzymes enable the reutilization of purine bases (adenine, guanine, hypoxanthine) converting them to mononucleotides (AMP, GMP, IMP), substrates for the synthesis of high-energy nucleotides. To confirm the hypothesis two experiments were performed: (i) in vitro, using a lysate of human erythrocytes incubated (5, 10, 30min) with lead ions (100microM, 10microM, 1microM, 500nM, 100nM lead acetate) and 100microM sodium acetate for the control, (ii) in vivo, using a lysate of rat erythrocytes taken from rats chronically exposed to lead (0.1% lead acetate in drinking water for 9 months, resulting in whole blood lead concentration 7microg/dL). The activities of APRT and HPRT were determined using HPLC method, which allowed concurrent determination of the activity of both enzymes in erythrocyte lysates. We have shown that, lead ions: (i) moderately inhibit both phosphoribosyltransferases in erythrocytes, this influence being detectable even at very low concentrations (ii) participate in hemolysis, the intensity of which negatively correlates with the activity of phosphoribosyltransferases. Our results indicate the necessity of further research on the role of lead-induced APRT and HPRT inhibition as one of the mechanisms of lead toxicity.

Prostaglandin E2 (PGE2) and thromboxane A2 (TXA2) synthesis is regulated by conjugated linoleic acids (CLA) in human macrophages.

Conjugated linoleic acid (CLAs) are positional and geometric isomers of linoleic acid with have a potential anti-atherosclerotic and anti-inflammation properties. Metabolites of arachidonic acid--prostaglandins and thromboxans--are endogenous mediators of inflammation. Prostaglandin E(2) and thromboxan A(2) which are a products of two izoformes of cyclooxygenases (COX-1 and COX-2) in macrophages, play an important role in this process. COX-1 is a constitutive enzyme, whereas the COX-2 is inducible and its amount in the cell rapidly increases during inflammation (e.g. via NF kappaB pathway). The aim of the study was to test the effect of CLAs on cyclooxygenases (COX-1 and COX-2) activity, their mRNA expression and protein content in macrophages. Additionally the active form of the kappaB (NF kappaB) transcription factor was measured. For the experiments monocytes from monocytic cell line (THP-1) and from human venous blood were used. Monocytes were differentiated to macrophages and cultured with 30 muM CLAs or linoleic acid for 48 h. The COX-1 and COX-2 products - PGE(2) and TXB(2), were measured by ELISA method. The enzymes (COX-s) activity were estimated by spectroscopic method. mRNA expression and protein analysis were analysed by real-time PCR and Western blot technique. In macrophages cultured with CLAs reduction of TXB(2) and PGE(2) concentration was observed. Significant change in COX-2 expression in cells cultured with trans-10, cis-12 CLA (in macrophages obtained from peripheral blood) was observed. COX-1 inhibition was resulting from competition of CLA and linoleic acid with arachidonic acid.

Activity of selected enzymes in erythrocytes and level of plasma antioxidants in response to single whole-body cryostimulation in humans.

The influence of extremely low temperatures on the human body and physiological reactions is not fully understood. The aim of this research was to estimate the influence of a single exposure to cryogenic temperature (-130 degrees C), without subsequent kinesiotherapy, on the activity of the most crucial antioxidant enzymes in erythrocytes: superoxide dismutase (SOD), catalase (CAT), glutathione reductase (R-GSSG), glutathione peroxidase (GPx) and glutathione transferase (T-GSH). In the plasma, the concentrations of glutathione, uric acid, albumins and extra-erythrocyte haemoglobin as components of the non-enzymatic antioxidant system were evaluated. The subjects were 10 healthy young men. Blood was sampled in the morning on the day of cryostimulation, 30 min after cryostimulation and the next morning. The enzymatic response of the antioxidant defence to the influence of the extremely low temperature resulted in an immediate, significant, increase in GPx and R-GSSG activities, but a decrease in CAT and T-GSH activities. We observed an increase in the concentrations of all the examined non-enzymatic antioxidants, especially extra-erythrocyte haemoglobin and uric acid, which had both increased further the day after cryostimulation. The results indicate that a single stimulation with cryogenic temperatures results in oxidative stress in a healthy body, but that the level of stress is not very high. It seems that in this case the most significant role in the antioxidant mechanisms is played by peroxidase.

Does glucose in dialysis fluid protect erythrocytes in patients with chronic renal failure?

BACKGROUND/AIMS: The aim of this study was to assess the multifaceted influence of glucose present in dialyzing fluid on erythrocytes of patients with chronic renal failure (CRF) undergoing regular hemodialysis. METHODS: A group of 44 subjects with CRF undergoing regular hemodialysis was studied. Two tests were used: osmotic fragility and resistance to the hemolytic agent saponin. The total content of isoprostane 8-iso-prostaglandin F2alpha type III (8-iPF2alpha-III) in plasma and erythrocyte's membrane were determined by the ELISA method. RESULTS: The presence of glucose in the dialysate is associated with lower intravascular hemolysis markers and high total 8-iPF2alpha-III concentrations in plasma. CONCLUSION: The presence of glucose in dialyzing fluid could protect erythrocytes. It limits hemolysis in patients with CRF, but, on the other hand, increases the oxidative processes. This kind of treatment along with other therapeutic intervention such as administration of antioxidants (e.g. alpha-tocopherol, ascorbic acid, N-acetylcysteine) could improve the condition of erythrocytes and outcome in CRF.

Metabolism of eicosanoids and their action on renal function during ischaemia and reperfusion: the effect of alprostadil.

Eicosanoids, active metabolites of arachidonic acid (AA), play an important role in the regulation of renal haemodynamics and glomerular filtration. Our study verified the hypothesis on the positive action of exogenously administered PGE(1) on renal function during an operation with temporary ischaemia of the lower half of the body. Also the effect of alprostadil (prostaglandin E(1) analogue) administered during the operation of an abdominal aorta aneurysm on the postoperative systemic metabolism of AA and the glomerular filtration rate (GFR) was investigated. The study included 42 patients with a diagnosed abdominal aorta aneurysm who have been qualified for the operation of implantation of the aortic prosthesis. The patients were randomly assigned to two groups: the study group (I) receiving alprostadil and the control group (II) without alprostadil. The levels of hydroxyeicosatetraenoic acids (15-HETE, 12-HETE, 5-HETE) were determined by RP-HPLC and the level of thromboxane B(2) (TxB(2)) was determined by ELISA in the plasma of the blood drawn from vena cava superior immediately before aortic clamping (A) and 5 min after aortic declamping (B). The administration of PGE(1) affects the metabolism of 15-HETE in a manner dependent on the baseline value of GFR but does not significantly change the postoperative renal function. The metabolism of 15-HETE is affected by the baseline value of GFR1 and a longer period of ischaemia is correlated with lower concentrations of 5-HETE during reperfusion. The results of our studies indicate that TxB(2) influences the postoperative function of kidneys.