Association of FGF19, FGF21 and FGF23 with carbohydrate metabolism parameters and insulin resistance in patients with chronic kidney disease.

Insulin resistance (IR) is characterised by increased gluconeogenesis in the liver and the resistance of peripheral receptors to insulin. Several factors, including IR, type 2 diabetes, new-onset diabetes after transplant (NODAT) and secondary parathyroidism, are related to chronic kidney disease (CKD). These factors are associated with higher mortality due to the increased risk of cardiovascular complications. Many factors have been identified as potential markers of IR in CKD. These factors include fibroblast growth factors (FGFs), a subfamily of endocrine polypeptides. In this study, we examined the association of FGF19, FGF21 and FGF23 with selected parameters related to carbohydrate metabolism and insulin resistance in non diabetic patients with predialysis CKD and in non diabetic patients after renal transplantation. The study included 108 non diabetic subjects: 40 patients with predialysis CKD, 45 patients with CKD who had undergone renal transplantation, and 23 healthy subjects (control group). In patients who had undergone renal transplantation, concentrations of FGF23 were increased compared to the control group and patients with predialysis CKD. The highest and lowest FGF19 concentrations were observed in CKD patients and in patients who had undergone kidney transplantation, respectively. This difference was statistically significant. Leptin concentrations were higher in CKD patients compared to the control group and patients who had undergone kidney transplantation. There were no statistically significant differences in adiponectin concentrations, lean body mass or fat tissue mass between the studied groups. HOMA-IR and insulin levels were significantly increased in CKD patients and in patients who had undergone renal transplantation in comparison to the control group. The results of the study suggest the involvement of FGF in carbohydrate metabolism and insulin resistance in patients with predialysis CKD, as well as a correlation with kidney function.

[Cancer or vitamin B12 deficiency? Difficult differential diagnosis in elderly]. / Nowotwór czy niedobór witaminy B12? Trudna diagnostyka róznicowa u osób starszych.

Vitamin B12 deficiency anaemia in adults is usually caused by Addison- Biermer's disease. The presence of antibodies against gastric parietal cells and intrinsic factor (IF) in blood is typical for the disease. The gastrointestinal malabsorption or a diet poor in vitamin B12 are rarer causes. The disease manifests in hematological, neurological, psychiatric disorders and trophic changes of the tongue and oral mucosa, which leads to weight loss. A CASE REPORT: The authors describe a case of a 70-year-old woman with severe vitamin B12 deficiency based on chronic inflammatory lesions of the gastric mucosa caused by Helicobacter pylori infection. The patient had haematological (pancytopenia), neurological (problems with memory, concentration, numbness of the limbs, gait instability) and gastrological disorders (loss of appetite, weight loss). The laboratory and imaging diagnostics were performed. The neoplasmatic background was abandoned and pure vitamin B12 deficiency was diagnosed. All symptoms resolved completely after the supplementation and eradication of Helicobacter pylori. CONCLUSIONS: The article demonstrates the problem of many severe, non- specific complications of vitamin B12 deficiency which requires extensive diagnostics and treatment. The similarity of symptoms may suggest a malignant disease especially in elderly patients.

Chronic Kidney Disease Is Associated with Increased Plasma Levels of Fibroblast Growth Factors 19 and 21.

BACKGROUND: Chronic kidney disease (CKD) is the result of a reduced number of nephrons, in which adipose tissue and its metabolites play a significant role. Fibroblast growth factors, FGF19 and FGF21, are involved in lipid and carbohydrate metabolism. The aim of the study was to examine the concentrations of FGF19 and FGF21 in patients with CKD, as well as the correlation between FGF19 and FGF21 and selected biochemical parameters. MATERIALS AND METHODS: The study included 178 subjects: 52 patients with CKD in stages 2-4, without haemodialysis (CKD), 47 haemodialysed patients with CKD (HD), 56 patients with CKD after a renal transplantation (Tx) and 23 healthy subjects as the control group (C). RESULTS: The highest FGF19 serum concentrations were observed in CKD patients and the lowest were observed in the Tx group. Patients in the CKD group had significantly higher serum FGF21 concentrations. There were negative correlations between FGF19 and glomerular filtration rate (GFR), as well as high-density lipoprotein cholesterol levels in patients after kidney transplantation. Negative correlations were also found between serum FGF21 concentrations and GFR in patients after Tx, while positive correlations were observed between FGF21 concentrations and lean body mass in the CKD group, body mass index and total cholesterol in the HD group. CONCLUSIONS: Our results suggest that increased concentrations of FGF19 and FGF21 in patients with CKD may be associated with the metabolism of lipids and carbohydrates. Our results also indicate that haemodialysis and transplantation results in the reduction of FGF19 and FGF21 concentrations in patients with CKD.

Association Between Plasma Concentration of Klotho Protein, Osteocalcin, Leptin, Adiponectin, and Bone Mineral Density in Patients with Chronic Kidney Disease.

Patients with early-stage chronic kidney disease (CKD) are susceptible to changes in metabolic processes. Partial loss of kidney function leads to homoeostatic disturbances in bone and fatty tissue. The aim of this study was to investigate the association between plasma concentrations of Klotho protein, FGF23, leptin, adiponectin, osteocalcin, and bone mineral density (BMD) in patients with CKD in the pre-dialysis period. The study involved 52 patients with CKD and 23 patients with no kidney disease. In both groups, BMD, body mass index and serum or plasma concentrations of lipids, glucose, creatinine, calcium, phosphorus, parathormone, leptin, adiponectin, osteocalcin, Klotho, and FGF23 were measured. The group with CKD had statistically significant higher concentrations of leptin (p<0.001), parathormone (p<0.001), and osteocalcin (p<0.001) in comparison with the control group. Patients with CKD also had statistically significant lower BMD in the femoral neck in comparison with the control group. Osteocalcin correlated negatively with BMD. The results of our study suggest that elevated osteocalcin is the most sensitive marker of decreased bone mass in patients with CKD. Osteocalcin correlated negatively with BMD and GFR. The loss of bone mass in CKD patients was greatest in the femoral neck.

The association of the Klotho polymorphism rs9536314 with parameters of calcium-phosphate metabolism in patients on long-term hemodialysis.

BACKGROUND: Patients on long-term hemodialysis frequently suffer from complications, such as secondary hyperparathyroidism, bone fractures, and arteriosclerosis. The process of regulating Ca/P metabolism depends on factors, such as FGF23 and Klotho. This study aimed to answer the question of whether the Klotho polymorphism rs9536314 is associated with FGF23 plasma concentration. METHODS: In 118 patients undergoing hemodialysis, blood was collected before and after hemodialysis. The following parameters were measured in plasma: FGF23, serum: Ca, P, PTH, HGB, and iron concentrations. The KL gene polymorphism rs9536314 was identified by PCR-RFLP. RESULTS: The KL polymorphism rs9536314 was not associated with Ca, P, PTH, or FGF23. There was a negative correlation between FGF23 and blood HGB levels and positive correlation between FGF23 and ESA dose. CONCLUSIONS: The results obtained may indicate that there is no association between the KL polymorphism and FGF23 concentration in patients undergoing long-term.

The impact of hemodialysis on erythrocyte membrane cytoskeleton proteins.

BACKGROUND: Hemodialysis (HD) is one of the methods of renal replacement therapy, but it also contributes to an increase in oxidative stress. Hemodialysis leads to changes in the erythrocyte cytoskeleton structure, whilst the presence of glucose in the dialysis fluid which activates the pentose phosphate pathway contributes to the intensification of oxidative stress. Available literature lacks reports on the effect of glucose in the dialytic fluid on the composition of proteins of the cell membrane cytoskeleton. MATERIAL/METHODS: Red blood cells for this analysis were collected from patients with chronic renal failure treated with hemodialysis using both glucose-containing and glucose-free dialysis fluid. Following the preparation of membranes, the electrophoretic separation of proteins was performed in denaturing conditions according to Laemmli. The level of tryptophan in membranes was determined by spectrofluorimetry, whilst the activity of glucose-6-phosphate dehydrogenase was determined by measuring the reduction of oxidated NADP. RESULTS: Hemodialysis in both groups of patients resulted in a statistically significant reduction of tryptophan as an oxidative stress indicator when compared to the control group. Moreover, the activity of glucose-6-phosphate dehydrogenase in the group of patients was higher than in the control group, and following the HD procedure it decreased, which may have been caused by a reduced concentration of dialyzed glucose. The HD procedure affects the structure of the erythrocyte membrane cytoskeleton, which is reflected in the concentration changes in individual proteins and in their mutual relationships corresponding to vertical and horizontal interactions stabilizing the structure of the erythrocyte membrane cytoskeleton. These changes may contribute to the shortening of cell lifespan.

Prooxidative-antioxidative balance of cells in different types of renal replacement therapy.

BACKGROUND: Patients suffering from chronic kidney disease (CKD) are exposed to increased oxidative stress and disturbances manifesting in the enzymatic and non-enzymatic antioxidative defence system. The object of the research was to assess the differences between conservative treatment, peritoneal dialysis and haemodialysis in moderating cellular antioxidative agents. METHODS: The group examined comprised 145 patients. The activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase were obtained using kinetic methods. The spectrophotometric method established the concentrations of reduced glutathione, albumin, uric acid, glucose, total protein and lipids. RESULTS: The type of treatment determined significant changes in antioxidative enzyme activities and concentrations of non-enzymatic antioxidative compounds. CONCLUSIONS: Peritoneal dialysis provides better antioxidant protection than other types of therapy in CKD and should be considered as first-choice treatment despite more metabolic disorders.

Lipid disorders - the comparison between general population and haemodialyzed patients. Will the Oral Fat Tolerance Test improve the diagnostic?

The cardiovascular events are frequent complications in chronic kidney disease (CKD). In the general population the risk factors of CV disease are well established and divided into two groups: non-modifiable, and modifiable. The best-known modifiable risk factors leading to the atherosclerotic plaque formation are lipid disorders. In comparison, an association between serum lipid profile in haemodialyzed patients and cardiovascular mortality is more complex and still unclear. Furthermore, it is important to note that recent studies suggest an inverse relationship between lipid disorders and CV mortality in a haemodialyzed population called 'reverse epidemiology'. The disparity between the general and haemodialyzed populations may be supported by the fact that the haemodialysis process itself contributes to the development of dyslipidaemia. Moreover, the chronic kidney disease is associated with metabolic abnormalities which can increase the risk of CVD occurrence. It is estimated that one-third of the patients on haemodialysis have lipid profile abnormalities, the most common one is hypertriglyceridemia. The assessment of the lipid profile has so far been performed in a fasting and non-fasting (postprandial) state, but both of these methods have some limitations. This review evaluates the current knowledge about lipid profile abnormalities in haemodialyzed patients and discusses a potential role of the Oral Fat Tolerance Test (OFTT) as a new tool in clinical practice that may improve the diagnosis of postprandial hypertriglyceridemia.

The Multifactorial Pathogenesis of Calciphylaxis: A Case Report.

BACKGROUND Calciphylaxis is a rare and lifethreatening syndrome characterized by small vascular calcifications, which lead to the occlusion of blood vessels and painful skin lesions with tissue necrosis. Although the disease can develop in a population without kidney failure, it is typically detected in patients receiving dialysis, with an increasing frequency ranging from 1% to 4%. Therefore, the disease is also known as calcific uremic arteriolopathy. The prognosis in patients with coexisting chronic kidney disease is very poor, with a 1-year mortality rate of up to 80%. Numerous risk factors for calciphylaxis have been described, such as obesity, diabetes mellitus, female sex, White race, overuse of calcium and vitamin D supplements, and vitamin K deficiency. The disease is often accompanied by disorders such as hyperphosphatemia, elevated parathyroid hormone level, and a deficiency of natural calcification inhibitors, such as fetuin-A and matrix Gla protein. However, not all patients with calciphylaxis have the abnormalities described above, suggesting that the pathogenesis of calciphylaxis is multifactorial and unfortunately still uncertain. CASE REPORT We report a case of calciphylaxis in a 52-year-old White woman with multiple comorbidities and on chronic hemodialysis treatment, who presented with severe subcutaneous painful nodules and necrotic ulcers on both legs. CONCLUSIONS Although the prognosis of this rare and underrecognized disease is poor, an early diagnosis and interdisciplinary treatment including pain relief, wound care, appropriate nutritional support, correction of mineral parameters, administration of sodium thiosulphate, and adequate hemodialysis therapy can improve patient quality of life.

Pure Red Cell Aplasia After Kidney Transplantation: Parvovirus B19 Culprit or Coincidence?

BACKGROUND Anemia is present even in long-term observation after kidney transplantation. Observational study results indicate the presence of chronic post-transplantation anemia in 1 in 3 recipients. An extreme form of erythroid line dysfunction is pure red cell aplasia (PRCA). It may be caused by immunosuppressive treatment per se or a side effect, opportunistic pathogen activation. Parvovirus B19 (PV B19) infection is quite likely the cause of refractory normocytic anemia in immunocompromised patients. CASE REPORT In this case report we discuss biological and clinical features of this phenomenon and the treatment strategies, based on 2 PRCA cases in kidney transplant recipients. Additionally, a systematic review of published reports of PV B19 related PRCA in kidney recipients is presented. CONCLUSIONS PV replication should be ruled out in cases of persistent and/or refractory anemia after kidney transplantation. The established first-line treatment of PRCA is passive immunization. Taking into account cost effectiveness, a decrease in immunosuppression load is reasonable under careful control of allograft function.

Biocompatibility of synthetic ultraviolet radiation cross-linked polymers - Subcutaneous implantation study.

Photo-cross-linked polymers have attracted a lot of attention in the biomedical field. The main benefits of these materials are related to the fact that they are most of the time viscous liquids or pastes that adapt a custom and fixed shape on demand of the user. Present study deals specifically with the biological response upon subcutaneous implantation of four different materials in rabbits. In the study 20 rabbits were divided into four groups (each five rabbits): Groups 1-3 were implanted with tested new obtained by us macromonomers (P1838-DMA; P1838-UR; PDEGA-UR - respectively), while group 4 (control) was implanted with the mesh (PLA) routinely used for surgical treatment of a hernia. The new compounds were polarized earlier using ultraviolet radiation to obtain cross-linked networks. The polymers in the form of discs were then implanted subcutaneously in dorsal region of rabbits. After 28 days polymers were explanted and examined. Microscopic observation evaluated: thickness of the connective tissue capsule around the discs, cells of inflammatory response, disc surface erosion, spectroscopic analysis. The examined materials cause no chronic inflammation, abscesses or tissue necrosis, and the biological response is similar to observed in control group. Therefore, new synthetic materials could be considered as biocompatible and safe. Materials undergo slow degradation of ester bonds and surface erosion and degradation products could be eliminated probably by phagocytosis. On the basis on the afore mentioned knowledge, we formulated hypothesis, that the new polymers are well tolerated by the adjacent tissues. The aim of the following study was to examine reaction of the tissue on new types of prepolymerized material implanted subcutaneously. The obtained results suggest, that the new UV cross-linked polymers do not affect negatively on the connective tissue that is in the contact with the implants. Furthermore, the used materials are in the liquid form, thus they could be easily performed in in minimally invasive laparoscopic treatment of abdominal hernias. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1889-1897, 2019.

The role of eicosanoids in renal diseases - potential therapeutic possibilities.

Eicosanoids are biologically active molecules that are created in the process of oxidation of arachidonic acid (AA) which is a constituent of the cell membrane phospholipids. Throughout the years it was evidenced by experiments that the lipid and lipid-derived metabolites play an important role in physiological and pathological processes in the kidneys. They are being considered as biomarkers in detecting acute kidney injury, nephrotoxicity, glomerulonephritis and early stages of diabetic nephropathy because of their participation in inflammatory processes and in oxidative stress. They might be also considered as potential novel targets of therapy. However, the role of eicosanoids is still not fully clear and needs to be explored in future studies. In this brief review, studies on the role of eicosanoids in physiological and pathological conditions, e.g. acute kidney injury (AKI) and chronic kidney disease (CKD), and in different renal replacement therapies, including kidney transplantation, are being discussed.

Bioactive lipids derived from arachidonic acid metabolism in different types of renal replacement therapy.

INTRODUCTION: Metabolism and plasma concentration of lipids and lipid-derived compounds play an important role in kidney physiology and pathological processes. The component of membrane phospholipids - arachidonic acid (AA) and its active derivatives - eicosanoids are involved in the development of hypertension, diabetes, inflammation and may contribute to progression of chronic kidney disease (CKD). The purpose of the study was to determine, whether the type of renal replacement therapy has an effect on eicosanoids metabolism. MATERIALS AND METHODS: The study included 145 patients with CKD: on conservative treatment (n=68), on peritoneal dialysis (PD) (n=23) and undergoing chronic haemodialysis (HD) (n=54). The concentrations of TXB2, 20-HETE, 8-epi-PGF2α in platelet poor plasma (PPP) were determined using the ELISA method and 5-HETE, 12-HETE, 15-HETE were measured using the RP-HPLC. RESULTS: The concentrations of TXB2 in HD group, both before (2.28±0.72ng/mL) and after (1.49±0.63ng/mL) haemodialysis treatment differed significantly from PD group (57.76±6.13ng/mL). Haemodialysis session led to the significant decrease in TXB2 plasma concentration (p=0.046). 20-HETE concentrations in HD group (113.55±107.54pg/mL and 199.54±142.98pg/mL before and after haemodialysis, respectively) were significantly higher than in CKD 3-5 group (8.96±12.66pg/mL) and PD group (47.78±34.07pg/mL). The highest concentration of 12-HETE was obtained in PD patients (3.58±3.99ng/mL) and differed significantly from HD group after haemodialysis (0.97±0.28ng/mL) and CKD3-5 group (1.06±0.52ng/mL). The concentrations of 5-HETE, 15-HETE and 8-epi-PGF2α-III did not differ significantly among examined groups. CONCLUSIONS: The concentrations of active AA metabolites depend on the mode of renal replacement therapy and are associated with intensity of oxidative stress. They might be considered as potential indicators of kidney damage.

Erythrocyte antioxidant defense system in patients with chronic renal failure according to the hemodialysis conditions.

BACKGROUND: Patients suffering from chronic renal failure (CRF) are exposed to increased oxidative stress generated by uremic toxins, factors connected with hemodialysis, chronic inflammatory state, lack of vitamins A, E and selenium, advanced age, and parenteral iron administration. Their antioxidative system is inefficient. In erythrocytes, hexosemonophosphate (HMP) cycle does not assure an adequate amount of reductive equivalents (NADPH) necessary to restore reduced glutathione (GSH), an important free radical scavenger. Hemodialysis treatment also causes a large loss of glucose, which is the basic substrate for that metabolic pathway. The object of the research was to establish the influence of glucose present in dialysate on antioxidant defense system in red blood cells. METHODS: A group of 51 patients undergoing regular hemodialysis using glucose (26 subjects, GL+ HD) or non-glucose fluid (25 subjects, GL- HD) was studied. The GSH concentration, glucose-6-phosphate dehydrogenase (G-6-P DH) and glutathione reductase (GSSG-R) activities were determined. Glucose concentration before and after the hemodialysis session was also measured. RESULTS: The activity of G-6-P DH was significantly higher in GL+ HD both before (p = 0.000) and after (p = 0.0002) the dialysis treatment compared to GL- HD, respectively, and to the healthy subjects (p = 0.000). The hemodialysis session caused a decrease in the activity of the enzyme in GL+ HD from 4.91 +/- 1.53 to 4.42 +/- 1.40 U/g Hb (p = 0.004) as well as in GL- HD from 3.97 +/- 1.00 to 3.59 +/- 0.87 U/g Hb (p = 0.007). The GSSG-R showed an increase in activity in CRF patients before HD (in GL+ HD to 2.57 +/- 0.76 and in GL- HD to 2.82 +/- 0.98 U/gHb). After dialysis, lower values were observed, particularly in GL+ HD (2.05 +/- 0.59 U/g Hb, p = 0.004). GSH concentrations in the examined group were higher (in GL+ HD 0.0205 +/- 0.008 and in GL- HD 0.0196 +/- 0.008 mmol/g Hb) than in controlled subjects (0.0142 +/- 0.002 mmol/g Hb) and decreased during dialysis treatment (considerably only in GL- HD to 0.0183 +/- 0.007 mmol/g Hb, p = 0.056). Glucose concentrations in GL+ HD were significantly higher compared to GL- HD (p < 0.002). CONCLUSIONS: Glucose presence in dialyzing fluid improves the HMP cycle activity as well as glutathione system reactions and determines a better antioxidant status of erythrocytes. It limits hemolysis and improves the hematological parameters in CRF.

The activity of antioxidant enzymes in blood platelets in different types of renal replacement therapy: a cross-sectional study.

PURPOSE: The changes in redox status characterise physiological platelet activation. Increased oxidative stress in chronic kidney disease (CKD) associated with uremic toxicity and procedures of renal replacement therapy leads to the impairment of antioxidant properties of platelets. It may contribute to thrombosis and cardiovascular complications increasing morbidity and mortality among the CKD patients. The object of the research was to assess the influence of conservative treatment, peritoneal dialysis and haemodialysis on platelet prooxidative-antioxidative balance. METHODS: The examined group consisted of 122 patients: 37 on regular haemodialysis (HD), 23 on peritoneal dialysis (PD) and 62 on conservative treatment with CKD stages 3-5 (CKD3-5). The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione transpherase (GST) in platelets were obtained using kinetic methods. The spectrophotometric method established the concentrations of reduced glutathione (GSH). RESULTS: SOD activity in PD differs significantly from CKD3-5 (4.96 vs 1.66; p < 0.0001). CAT activity assessed in PD and CKD3-5 was significantly different from HD (0.82 and 0.8 vs 0.52 before and 0.35 after HD, respectively). GST activity reached the highest value in PD (1.62), and it was significantly different from CKD3-5 (0.23) and HD before haemodialysis (0.11). During haemodialysis therapy, there was a considerable increase in GST activity (0.11 vs 0.3; p = 0.02) and decrease in SOD activity (from 3.41 to 2.27; p = 0.01). The highest GSH concentrations were obtained in CKD3-5 and differ significantly from HD (4.12 vs 2.01; p = 0.02). CONCLUSIONS: The type of treatment, age and duration of renal replacement therapy determined significant changes in platelet antioxidative enzymes activities and concentration of GSH, which may enhance the thrombotic complications. PD is associated with lower platelet oxidative stress.

The Role of Klotho Protein in Chronic Kidney Disease: Studies in Animals and Humans.

The identification of Klotho gene was a major discovery as the gene encodes a protein regulating multiple functions. A defect in Klotho gene expression in mice results in a phenotype of premature aging including shortened life span, growth retardation, hypogonadism, skin and muscle atrophies, vascular calcification, cognition impairment, motor neuron degeneration and others. This phenotype is associated with phosphate balance disorders and underlines the major function of Klotho in mineral metabolism. As another 2 related paralogs were discovered (beta-Klotho, which is involved in bile acid and energy metabolism, and gamma-Klotho, with a yet to be defined function), this led to the revised naming of Klotho as alpha-Klotho. Two forms of alpha-Klotho protein have been reported: a membrane-bound and a soluble one. Membrane Klotho forms a complex with fibroblast growth factor (FGF) receptors and functions as an obligate co-receptor for the FGF-23 phosphatonin in distal tubules. The soluble form of Klotho seems to function as a humoral factor and regulates glycoproteins on the cell surface including ion channels and growth factors. There is data suggesting that soluble Klotho exerts phosphaturic effects independently of FGF-23. Circulating soluble Klotho is produced either by proteolytic cleavage of the extracellular domain of the transmembrane form by two membrane-anchored proteases (ADAM10 and ADAM17) or by alternative mRNA splicing. In animal models Klotho has been shown to exert pleiotropic actions, including cytoprotection, anti-oxidation, anti-apoptosis, protection of vasculature, promotion of angiogenesis and vascularization, inhibition of fibrogenesis and preservation of stem cells. The exact diagnostic and therapeutic role of Klotho in humans is not fully known yet. The article presents the role of Klotho in physiology and different stages of chronic kidney disease (CKD).

Platelet - derived CD154 antigen in patients with chronic kidney disease.

INTRODUCTION: CD154 is a surface glycoprotein present on activated platelets, lymphocytes and mast cells. It mediates the transmission of information between cells and initiates an inflammatory response. The interaction of CD154 with its receptor CD40 leads to increase in concentrations of soluble forms of both molecules (sCD154, sCD40), which has an important prognostic value in cardiovascular complications. The metabolic disorders in chronic kidney disease (CKD), chronic inflammation, increased oxidative stress and type of renal replacement therapy may influence on the balance of sCD154/sCD40 in plasma and blood platelets. The purpose of the reasearch was to analyse the concentrations of sCD154 antigen and sCD40 receptor in platelet pure plasma (PPP) and platelet rich plasma (PRP) of patients with CKD treated conservatively, haemodialysed and on petitoneal dialysis. METHODS: The group examined comprised 141 patients with chronic kidney disease: in pre-dialysis stage (n = 68), haemodialysed (n = 38) and on peritoneal dialysis (n = 35). The concentrations of sCD154 and sCD40 in PRP and PPP were determined with an ELISA method. The biochemical parameters were obtained using colorimetric method. RESULTS: The concentrations of sCD154 and sCD40 in PPP and PRP in examined group were significantly different depending on the method of renal replacement therapy. The haemodialysis procedure caused a significant increase in sCD40 concentration in PRP. The concentrations of sCD40 and sCD154 were correlated with lipid parameters. CONCLUSIONS: The type of renal replacement therapy influences on platelet activation which may be a factor contributing to increased cardiovascular complications in patients suffering from CKD.

[Oxidative stress as a reason of treatment difficulties in chronic renal failure]. / Stres oksydacyjny jako jedna z przyczyn trudnosci w leczeniu przewleklej niewydolnosci nerek.

The erythrocytes of patients suffering from chronic renal failure (CRF) are exposed to an increased activity of free radicals. These compounds are generated by uremic toxins and hemodialysis itself. They cause the peroxidation of lipids and proteins in red blood cell membrane. It leads to a decrease of erythrocytes' stability and a lower resistance to hemolysis. The advanced oxidation protein products and advanced glycation end products (AOPP and AGE) also contribute to these changes. The described processes deepen the anemia in CRF and make difficulties in its treatment. In addition, the quoted references present a lot of disturbances in activities of the enzymes and metabolic pathways, which provide antioxidant reactions. This group consists of: superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), glutathione reductase (GSSG-R) end the enzymes of the pentose-phosphate shunt (PPS). The intensity of changes is according to the stage of the disease and the efficiency of treatment. Its most appropriate form is renal transplantation.

[Frequency and incidence of myopia among medical students]. / Wystepowanie krótkowzrocznosci szkolnej u studentów medycyny.

PURPOSE: To estimate the frequency and dynamic changes in refractive errors in population of students of medical (MF) and dental (DF) faculties of Pommeranian Medical Academy in Szczecin. MATERIAL AND METHODS: Medical records from ophthalmic examinations performed in 176 medical students (117 females and 59 males) during the 2nd and 4th course of studies were analyzed (2-years long observation). RESULTS: Refractive error was found in 42% of MF students and 39.5% of DF students on the 2nd course and in 51% and 47% on the 4th course respectively. Myopia was found in 75% of ametropic eyes. In 2 years observation time, there was a statistically significant progression of refracive error in 50% of myopic students (from -2.9 +/- 2.3 D to -3.4 +/- 1.9D in MF and from -2.0 +/- 1.5 to -2.4 +/- 1.5D in DF). Myopia developed in 13% of initially emmetropic students.

Oxidative stress and antioxidative enzyme activities in chronic kidney disease and different types of renal replacement therapy.

The incidence and diagnosis of chronic kidney disease (CKD) is on the rise all over the world. CKD is related to ageing of the society and high morbidity due to lifestyle diseases like diabetes, atherosclerosis, and hypertension. CKD is associated with increased oxidative stress generated by uremic toxicity, chronic inflammatory state, lack of vitamins and microelements, parenteral iron administration, and dialysis procedure itself. In terms of cellular physiology, erythrocytes and blood platelets in particular have effective enzymatic and non-enzymatic antioxidative system. The most efficient enzymatic antioxidants include superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase. Glutathione is the leading non-enzymatic free radical scavenger. In CKD, antioxidative defense is impaired and the abnormal activity of the enzymes and glutathione concentration is described in literature. The imbalance between the formation of reactive oxygen species and antioxidative system efficiency takes part in the pathogenesis of cardiovascular complications. It contributes to increased morbidity and mortality in patients with CKD. The severity of these processes depends on the type of renal replacement therapy; haemodialysis (HD) is more predisposing to such disorders than peritoneal dialysis (PD), or even conservative treatment. This can influence the outcome and the possibility of kidney transplantation. Moreover, the early function of kidney allograft seems to be dependent on perioperative antioxidative ability of platelets, which can play a potential protective role in kidney transplantation.