The Role of Oxidative Stress in the Risk of Cardiovascular Disease and Identification of Risk Factors Using AIP and Castelli Atherogenicity Indicators in Patients with PCOS.

Polycystic ovarian syndrome (PCOS) is one of the most common endocrinopathies in females of reproductive age and may affect 5-14% of women. In women with PCO syndrome, metabolic disorders such as insulin resistance, hyperinsulinemia, obesity, diabetes mellitus, and other elements of metabolic syndrome may occur. Patients with PCOS often have overweight and obesity, especially abdominal obesity, which is one of the risk factors for developing atherosclerosis. The atherogenicity indicators of AIP (atherogenic index of plasma) and Castelli's index are used to assess the risk of developing atherosclerosis. Studies have shown an increase in the concentration and activity of oxidative stress markers in patients with PCOS compared to women without the disease. The aim of the present study was to evaluate oxidative stress parameters in patients with PCOS in relation to insulin resistance, BMI, and hyperandrogenemia and to correlate them with cardiovascular risk parameters. Conclusions: The severity of oxidative stress in women with PCOS correlates with exposure to cardiovascular diseases. The assessment of additional cardiovascular disease (CVD) parameters is useful in identifying the risk groups for cardiometabolic disease among PCOS patients. When additional risk factors such as hyperandrogenism and insulin resistance (IR) are present in patients with PCOS, it is reasonable to include preventive examinations early. It is also important to evaluate lipidograms, which will make it possible to determine indicators of atherogenicity. Patients with PCOS and IR are at particular risk for cardiovascular complications. PCOS should be considered an important risk factor for CVD, which occurs independently of the occurrence of obesity. This factor is related to the important role of insulin resistance, which occurs independently of obesity. Atherogenic factors (AIP and Castelli index) are useful additional parameters to assess the risk of cardiometabolic disease in PCOS patients, especially among groups with insulin resistance. The early detection of risk factors should be an integral part of the care of PCOS patients. In laboratory studies of women with PCOS, TG, TChol, HDL-c and LDL-c levels, and glutathione peroxidase (GPx) activity were most clearly correlated with exposure to cardiovascular disease.

Assessment of the Parameters of Oxidative Stress Depending on the Metabolic and Anthropometric Status Indicators in Women with PCOS.

Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies in females of reproductive age. In women with PCOS, metabolic disorders such as insulin resistance (IR), hyperinsulinemia, obesity, diabetes mellitus, and other elements of metabolic syndrome are likely to occur. Studies have shown an increase in the concentration and activity of oxidative stress (OS) markers in patients with PCOS, compared to that in unaffected women. The aim of this study was to evaluate the parameters of OS in PCOS and their activity in relation to women without menstrual disorders with a normal body weight. Then, we compared malonodialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), including overweight and obesity, hyperandrogenemia, and IR in the PCOS group. The study included 35 women aged 18-46, hospitalized for menstrual disorders in the form of infrequent menstruation. In 26 women, PCOS was diagnosed on the basis of the Rotterdam Criteria; these patients qualified for the study group. The control group (n = 21) consisted of patients without menstrual disorders and without PCOS in an ultrasound examination. Patients were diagnosed between the 2nd and 5th day of the cycle. The parameters of OS were analyzed and compared with the anthropometric parameters and the lipid profile of the patients. Enzymatic activity of GPx, CAT, SOD, and MDA levels was determined in both groups. MDA levels and CAT activity differed significantly between the groups. There was a decrease in MDA levels in the IR group and the involvement of GPx in the excess weight and obesity and IR group accompanied by an increase in hip circumference. It therefore seems that IR may be the main risk factor to exposure to OS in patients with PCOS, independent from obesity. In addition, GPx is involved in every step in the development of the pathological condition in PCOS.

The role of the electrokinetic charge of neurotrophis-based nanocarriers: protein distribution, toxicity, and oxidative stress in in vitro setting.

BACKGROUND: The rational chemical design of nanoparticles can be readily controlled and optimized by quantitatively studying protein adsorption at variously charged polymer carriers, determining their fate in biological fluids. We manufactured brain-derived neurotrophic factor (BDNF) -based electrostatic nanocomplexes with a different type of dendrimer core (anionic or cationic), encapsulated or not in polyethylene glycol (PEG), and studied their physicochemical properties and behavior in a biological setting. We investigated whether the electrokinetic charge of dendrimer core influences BDNF loading and desorption from the nanoparticle and serves as a determinant of nanoparticles' behavior in in vitro setting, influencing mitochondrial dysfunction, lipid peroxidation, and general nanoparticles' cellular toxicity. RESULTS: We found that the electrokinetic charge of the dendrimer core influences nanoparticles in terms of BDNF release profile from their surfaces and their effect on cell viability, mitochondrial membrane potential, cell phenotype, and induction of oxidative stress. The electrostatic interaction of positively charged core of nanoparticles with cell membranes increases their cytotoxicity, as well as serious phenotype alterations compared to negatively charged nanoparticles core in neuron-like differentiated human neuroblastoma cells. Moreover, PEG adsorption at nanoparticles with negatively charged core presents a distinct decrease in metabolic cell activity. On the contrary, charge neutralization due to PEG adsorption on the surface of nanoparticles with positively charged core does not reduce their cytotoxicity, makes them less biocompatible with differentiated cells, and presumably shows non-specific toxicity. CONCLUSIONS: The surface charge transformation after adsorption of protein or polyelectrolyte during nanocarriers formulation has an important role not only in designing nanomaterials with potent neuroprotective and neuroregenerative properties but also in applying them in a cellular environment.

Inflammation markers are associated with metabolic syndrome and ventricular arrhythmia in patients with coronary artery disease.

BACKGROUND: Inflammation plays a major role in the development and progression of atherosclerosis and coronary artery disease (CAD). Inflammation markers, including white blood cell (WBC) count, C-reactive protein (CRP) and interleukin-6 (IL-6), are widely used for cardiovascular risk prediction. The aim of the study was to establish factors associated with WBC, CRP and IL-6 in patients with CAD. Two functional polymorphisms in genes encoding enzymes participating in adenosine metabolism were analyzed (C34T AMPD1, G22A ADA). METHODS: Plasma concentrations of IL-6 were measured using high-sensitivity ELISA kits, and the nephelometric method was used for high-sensitivity CRP (hs-CRP) measurement in 167 CAD patients. RESULTS: Presence of metabolic syndrome (MS) and its components, presence of heart failure, severity of CAD symptoms, severe past ventricular arrhythmia (sustained ventricular tachycardia [sVT] or ventricular fibrillation [VF]), lower left ventricle ejection fraction, higher left ventricle mass index, higher end-diastolic volume and higher number of smoking pack-years were significantly associated with higher WBC, CRP and IL-6. Strong associations with arrhythmia were observed for IL-6 (median 3.90 vs 1.89 pg/mL, p<0.00001) and CRP concentration (6.32 vs 1.47 mg/L, p=0.00009), while MS was associated most strongly with IL-6. CRP and IL-6 were independent markers discriminating patients with sVT or VF. There were no associations between AMPD1 or ADA genotypes and inflammation markers. CONCLUSIONS: WBC, CRP and IL-6 are strongly associated with components of the metabolic syndrome. Their strong association with life-threatening ventricular arrhythmia emphasizes the proarrhythmic role of inflammation in the increased cardiovascular risk of CAD patients.

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.

Influence of daily diet on ascorbic acid supply to students.

BACKGROUND: Researchers suspect that the accepted adequate ascorbic acid plasma concentration is not being met even after dietary intake of the recommended amount of vitamin C. Current dietary intake recommendation in Poland is 60 mg per day for women and 75 mg per day for man (EAR), while in Western Europe and North America is higher and amounts to 75-90 mg per day. OBJECTIVE: The paper aimed at studying a correlation between composition of nutrients in daily diet and plasma vitamin C levels in university students. Materials and methods. This study examined diet composition and the nutritional status of ascorbic acid in plasma of 120 university students in Szczecin, Poland. Ascorbic acid was determined in blood plasma using HPLC method. The information concerning diet composition was collected using the method of "7-days food record" prior to blood collection. RESULTS: Plasma ascorbic acid deficiency (<40 µmol/L) was observed in 23% of women and 28% of men. The average plasma ascorbic acid concentration was 48.65 µmol/L in women and 45.61 µmol/L in men. The average intake of vitamin C in women with observed deficiency was average 46.55 mg/day, whereas in men it was 48.56 mg/day. CONCLUSIONS: The recommendation of dietary intake of vitamin C in Poland is low in comparison to other countries. Population- based studies are necessary to determine the actual demand for vitamin C in various population groups in Poland. Key words: nutrition, vitamins, dietary intake, diet, ascorbic acid, plasma.

Calcium-phosphate metabolism parameters and erythrocyte Ca(2+) concentration in autosomal dominant polycystic kidney disease patients with normal renal function.

INTRODUCTION: The aim of this study was to assess calcium-phosphate metabolism of autosomal dominant polycystic kidney disease (ADPKD) patients with a special consideration to the following serum parameters: calcium (Ca(2+)), inorganic phosphate (Pi), parathyroid hormone (PTH) and intracellular erythrocyte calcium ([Ca(2+)]i) concentrations. MATERIAL AND METHODS: The study included 49 adult ADPKD patients (19 males, 30 females) aged 36 ±11 years with normal renal function and no diagnosis of diabetes as well as 50 healthy controls (22 males, 28 females) matched for age and gender. Serum concentrations of sodium (Na(+)), potassium (K(+)) and magnesium (Mg(2+)) ions and Pi were determined with an indirect ion-selective method, while Ca2+ concentration was measured with a direct ion-selective method. The PTH was detected using a radioimmunometric method. [Ca(2+)]i concentration was determined with the Ca(2+) sensitive fluorescent dye Fura-2 method. RESULTS: IN THE ADPKD GROUP, WHEN COMPARED TO CONTROLS, THE FOLLOWING CONCENTRATIONS WERE SIGNIFICANTLY HIGHER: serum Ca(2+) (1.18 ±0.06 mmol/l vs. 1.15 ±0.06 mmol/l, p = 0.0085), [Ca(2+)]i (146.9 ±110.0 nmol/l vs. 96.5 ±52.7 nmol/l, p = 0.0075), serum Na+ (139.4 ±2.7 mmol/l vs. 138.5 ±2.1 mmol/l, p = 0.060, borderline significance), and PTH (15.5 ±6.8 pg/ml vs. 13.6 ±5.3 pg/ml, p = 0.066, borderline significance), while serum Mg(2+) was significantly lower (0.81 ±0.09 mmol/l vs. 0.85 ±0.05 mmol/l, p = 0.021). In the ADPKD group we observed significant negative correlations of PTH with Ca(2+) serum concentrations (Rs = -0.32, p = 0.025) and with estimated glomerular filtration rate (Rs = -0.31, p = 0.033). CONCLUSIONS: The erythrocyte Ca(2+) concentration is elevated in ADPKD patients with normal renal function. It may result from a dysfunction of mutated polycystins which can affect various aspects of electrolyte metabolism.

Association of CD36 gene polymorphisms with echo- and electrocardiographic parameters in patients with early onset coronary artery disease.

INTRODUCTION: CD36 plays an important role in long-chain fatty acid homeostasis in skeletal muscle and the myocardium. CD36 deficiency may lead to reduced myocardial uptake of long-chain fatty acid. Therefore, different mutations of the CD36 gene may contribute to the clinical heterogeneity of cardiac hypertrophy. MATERIAL AND METHODS: The objective of the study was to investigate whether there is an association between the sequence changes in CD36 and echocardiographic and electrocardiographic parameters in Caucasian patients with early onset coronary artery disease. The study group comprised 100 patients. Electrocardiography and echocardiography were performed in all patients. Amplicons of exons 4 to 6 including fragments of introns were studied using the denaturing high-performance liquid chromatography technique. RESULTS: IVS3-6TC (rs3173798) heterozygotes had impaired left ventricle diastolic function. 573GA heterozygotes (rs5956) had higher frequency of pseudonormal left ventricular diastolic function and it was confirmed by the increase in wave A' in the tissue Doppler. 591AT genotype was associated with borderline higher posterior wall end-diastolic thickness and lower E/A ratio. These results are consistent with electrocardiography parameters which could reflect left ventricular hypertrophy (higher RV5(6) and RV5(6) + SV1(2) parameters, depressed ST segments and tendency to longer Qtc II interval) in 591AT heterozygotes. CONCLUSIONS: Detected variant alleles of CD36 may be associated with features of left ventricular hypertrophy and impaired diastolic function.

Can we predict urinary stone composition based on an analysis of microelement concentration in the hair and urine?

BACKGROUND: In recent years the role of trace elements in lithogenesis has received steadily increasing attention. OBJECTIVES: This study was aimed to attempt to find the correlations between the chemical content of the stones and the concentration of chosen elements in the urine and hair of stone formers. MATERIAL AND METHODS: The proposal for the study was approved by the local ethics committee. Specimens were taken from 219 consecutive stone-formers. The content of the stone was evaluated using atomic absorption spectrometry, spectrophotometry, and colorimetric methods. An analysis of 29 elements in hair and 21 elements in urine was performed using inductively coupled plasma-atomic emission spectrometry. RESULTS: Only a few correlations between the composition of stones and the distribution of elements in urine and in hair were found. All were considered incidental. CONCLUSIONS: The data obtained did not allow for the creation of a proper and practical algorithm to predict stone chemical composition based on hair and urine analysis.

Polymorphism of CD36 gene, carbohydrate metabolism and plasma CD36 concentration in obese children. A preliminary study.

INTRODUCTION: CD36 may play an important role in removal of oxidized LDLs from plasma, protein glycation, the pathogenesis of insulin resistance, type 2 diabetes, and diabetic micro- and macroangiopathy. Some reports have pointed to decreased expression of macrophages in association with mutations of the CD36 gene in hyperglycemic and obese subjects. The aim of the study was to search for an association between CD36 gene polymorphism and carbohydrate metabolism disturbances or variability of plasma soluble CD36 concentrations in obese children. MATERIAL/METHODS: The study included 60 children aged 10 to 15 years: 30 with (study group) and 30 without (control group) obesity. Each patient's glycated hemoglobin, weight, height, waist and hip circumference, and systolic and diastolic blood pressure were measured, BMI, WHR and MAP were calculated, and oral glucose tolerance test was performed with glucose and insulin concentration measurements. Amplicons of exons 4-6 of CD36 were studied using DHPLC technique. The PCR products with alterations were bidirectionally sequenced. Plasma concentrations of human antigen CD36 was measured using a commercially available enzyme-linked immunosorbent assay (ELISA). RESULTS: We found two intronic alterations: IVS3-6 T/C (rs3173798) and IVS4-10 G/A (rs3211892), one nonsynonymous substitution: G367A (Glu123Lys, rs183461468) in exon 5 and two synonymous transitions in exon 6: G573A (Pro191Pro, rs5956) and A591T (Thr197Thr, rs141680676). There were no significant differences in any biochemical or morphometric parameters between genotype groups. DISCUSSION: The polymorphisms of the studied fragment of CD36 are not associated with carbohydrate metabolism disturbances or the variability of plasma soluble CD36 concentrations in obese children, but further research is necessary to assess their functional implications.

Oxidative stress modulates the organization of erythrocyte membrane cytoskeleton.

BACKGROUND: Apart from their main role in transporting oxygen and carbon dioxide, erythrocytes play also an important role in organism antioxidative defence. Direct exposure to reactive oxygen species (ROS) results in shortening of their half-life, even by 50%. The presence of glucose, being the substrate in pentose phosphate pathway (PPP) cycle, is one of the factors that can have influence on the level of oxidative stress. The activity of PPP increases during oxidative stress. Glucose guarantees normal PPP functioning with the production of reductive equivalents in the amounts necessary to reproduction of glutathione--nonenzymatic free radical scavenger. In available literature there are no reports regarding the changes in protein contents of erythrocyte cytoskeleton exposed to t-butyl hydroperoxide in relation to glucose presence in incubation medium. MATERIAL/METHODS: Erythrocytes taken from 10 healthy subjects were used to assess the influence of generated free radicals on erythrocyte proteins and chosen parameters of oxidative stress. Erythrocytes were incubated in the solutions containing deferent concentrations of t-butyl hydroperoxide and glucose. Electrophoresis was performed on polyacrylamide gel in denaturating conditions. The contents of tryptophan in membranes was evaluated spectrofluorometrically. RESULTS/CONCLUSIONS: In vitro conditions oxidative stress leads to protein damage in erythrocyte cytoskeleton, both in proteins inside the cell as well as having contact with extracellular environment. In consequence, the amount of low-molecular proteins--mainly globin, which bind to cytoskeleton, increases. This process takes place independently of glucose presence in incubation medium. One of the element of protein cytoskeleton, tryptophan, also undergoes degradation. The decrease of its contents is higher during erythrocyte exposure to t-BOOH in environment containing glucose, what can suggest prooxidative influence of glucose in conditions in vitro.

Presence of glucose in dialyzing fluid and synthesis of selected lipoxygenase-derived eicosanoids during hemodialysis.

PURPOSE: Active metabolites of arachidonic acid (AA), eicosanoids, are exerting a significant influence on renal homeostasis. In our recent paper, we demonstrated that high levels of lipoxygenase (LOX)-derived AA metabolites, hydroxyeicosatetraenoic acids (HETEs), unfavorably influence post-transplant function of kidney allografts. Hence, in this study, we wanted (1) to analyze 5-, 12- and 15-HETE levels in non-diabetic chronic kidney disease (CKD) patients, already undergoing regular hemodialysis treatment, and determine factors that may influence these eicosanoids' generation, as well as, (2) to verify whether application of glucose-containing, instead of glucose-free, dialyzing fluids may be beneficial for the limitation of 5-, 12- and 15-HETE synthesis during a single hemodialysis session. METHODS: Twenty-four healthy individuals and 50 CKD patients undergoing regular hemodialysis treatment were included in the study. CKD patients were divided into two subgroups depending on presence/absence of glucose in dialyzing fluid. LOX-derived HETEs were measured using liquid chromatography. RESULTS: Results demonstrated higher levels of examined eicosanoids in CKD patients (P<0.05 for all). Older age and higher C-reactive protein levels were associated with HETEs concentrations. Presence of glucose in dialyzing fluid significantly diminished the increase in 5- and 12-HETE synthesis (411.24% vs. 107.29%, P<0.006; 301.70% vs. 98.21%, P<0.0008, respectively), however, it did not influence 15-HETE generation (156.98% vs. 135.24%, P=0.26). CONCLUSIONS: Non-diabetic CKD patients have higher levels of LOX-derived HETEs, which are associated mainly with age and intensified inflammatory process. The presence of glucose in the dialysate is associated with a reduced synthesis of selected LOX-derived HETEs in these patients; hence, we speculate that the application of such a simple hemodialysis fluid modification may have a favorable influence on post-transplant outcomes.

Polymorphism of the CD36 Gene and Cardiovascular Risk Factors in Patients with Coronary Artery Disease Manifested at a Young Age.

This study investigates potential associations between CD36 gene variants and the presence of risk factors in Caucasians with coronary artery disease (CAD) manifested at a young age. The study group consisted of 90 patients; the men were ≤ 50 years old and the women were ≤ 55 years old. Amplicons of exons 4 and 5 including fragments of introns were analyzed by DHPLC. Two polymorphisms were found: IVS3-6 T/C (rs3173798) and IVS4-10 G/A (rs3211892). The C allele of the IVS3-6 T/C polymorphism was associated with higher prevalence of obesity and diabetes, higher hsCRP, lower Lp(a) serum concentrations, and younger age at myocardial infarction. The A allele of the IVS4-10 G/A polymorphism was associated with older age of myocardial infarction and higher white blood cell count. The functional role of CD36 polymorphisms in CAD development needs further research.

Disrupted pro- and antioxidative balance as a mechanism of neurotoxicity induced by perinatal exposure to lead.

The aim of this paper was to examine if pre- and neonatal exposure that results in lead (Pb) concentration below 'safe level' (10 µg/dL) in offspring blood may cause disruption of the pro/antioxidant balance in the developing rat brain. We studied oxidative stress intensity (malondialdehyde (MDA) concentration) as well as mRNA, protein expression and the activity of copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), glutathione peroxidase (GPx), phospholipid hydroperoxide glutathione peroxidase (GPx4), catalase (CAT), glutathione reductase (GSR). We also measured glutathione (GSH) concentrations in selected structures of the rat brain (forebrain cortex, FC, cerebellum, C, and hippocampus, H) and showed cellular localization of GPx4, SOD1 and SOD2 expressions in the hippocampus by immunohistochemical examinations. Despite low Pb level in blood we observed decrease of the activity of some antioxidant enzymes as well as mRNA and protein expression downregulation associated with an increase of MDA level and CAT expression upregulation, especially in the hippocampus region. At the subcellular level, downregulation of SOD2 expression and decreased enzyme activity as well as mitochondrial pool of GSH suggest also that mitochondrial mechanisms might account for Pb neurotoxicity mechanism. For some enzymes, we found differences in the effects of Pb on the level of expression and activity. The activity of CAT decreased despite an increase in mRNA and protein expression; and likewise the activities SOD1, GPx1 GPx4 decreased, despite substantially unchanged level of expression. These effects may be the result of impairment of catalytic function of the enzyme protein caused by Pb interaction or of reduction in the availability of cofactors. We conclude that antioxidant system of the hippocampus of immature rat brain is highly vulnerable to perinatal Pb exposure. Therefore, oxidative stress may be one of the possible mechanisms disturbing cellular metabolism in this structure. Disruption of pro- and antioxidant balance should be considered as a potential mechanism of the observed Pb adverse effects, leading to the impaired learning ability caused by Pb exposure in children.

[Metformin - mechanisms of action and use for the treatment of type 2 diabetes mellitus]. / Metformina - mechanizmy dzialania i zastosowanie w terapii cukrzycy typu 2.

Metformin is widely used for the treatment of type 2 diabetes mellitus. Although this biguanide derivative has been used for more than 50 years, its mechanism of action has not been fully elucidated. In this article we describe the latest achievements concerning the mechanisms of antihyperglycemic action of metformin. They include: decrease of glucose absorption in the small intestine, increase of glucose transport into cells, decrease in the plasma free fatty acid concentrations and inhibition of gluconeogenesis. Activation of AMP-activated protein kinase (AMPK) plays an important role in these processes. The latest discoveries have revealed mechanisms of anti-atherosclerotic, hypotensive and anticancer action of metformin and its impact on vein endothelial function. The pleiotropic actions of metformin include impact on plasma lipid profile, decrease of oxidative stress, and increase in plasma fibrinolytic activity. Although metformin is not metabolized, the latest research has shown that it is actively transported into hepatocytes and renal tubular epithelium, by OCT1 (organic cation transporter 1, encoded by the SLC22A1 gene) and OCT2 (organic cation transporter 2, encoded by the SLC22A2 gene), respectively. However, MATE1 transporter (multidrug and toxin extrusion 1 protein) is encoded by the SLC47A1 gene and facilitates metformin excretion from these cells into bile and urine. Metformin transporter gene polymorphisms may contribute to significant variation in drug response. Further studies of mechanisms of metformin action could contribute to its wider use for the prevention of type 2 diabetes mellitus, cancer, and Alzheimer's disease, and for the treatment of type 1 diabetes mellitus, and polycystic ovary syndrome (PCOS).

The effect of L-ascorbic acid and/or tocopherol supplementation on electrophysiological parameters of the colon of rats chronically exposed to lead.

BACKGROUND: The aim of this study was to assess the effect of diet supplementation with L-ascorbic acid (500 mg/L), tocopherol (3 mg/kg b.w.), and/or a water soluble analog of tocopherol (Trolox) (48 mg/L) on ion transport in the colon of rats subjected to a chronic exposure (9 months) to 0.1% lead acetate in drinking water. MATERIAL/METHODS: The electrophysiological parameters of the colon wall were measured with Ussing methods. Lead content in the whole blood was analyzed by graphite furnace atomic absorption spectrometry (GFAAS) using Zeeman correction. L-ascorbic acid and tocopherol in plasma was measured by high performance liquid chromatography. Immunohistochemical reaction was carried out for visualization of occludin, the intracellular tight junction protein. RESULTS: We showed a strong inhibitory effect of lead on the electrophysiological parameters, changes in intestinal permeability, disappearance of junctional occludin, decreased amount of mucus covering the colon surface, and the accumulation of PAS-positive substance in the apical region of the cytoplasm in the absorptive cells. CONCLUSIONS: Supplementation with tocopherol or Trolox did not exert a beneficial influence on the studied parameters. L-ascorbic acid positively influenced the examined electrophysiological parameters, as it cancelled the inhibitory influence of lead on ion transport in the rat colon. L-ascorbic acid also protected against tight junction disruption of epithelial cells in the colon of the lead-treated rats. A similar effect was observed in the group of rats receiving lead and supplemented with L-ascorbic acid plus Trolox.

AMPD1 gene mutations are associated with obesity and diabetes in Polish patients with cardiovascular diseases.

Previous studies showed an association of the common functional polymorphism (C34T, Gln12Stop) in the adenosine monophosphate deaminase-1 (AMPD1) gene with survival in heart failure (HF) and/or coronary artery disease (CAD). The aim of the study was to search for other mutations in selected regions of the AMPD1 gene in Polish CAD and HF patients, and to analyze their associations with obesity and diabetes. Exons 2, 3, 5, and 7 of AMPD1 were scanned for mutations in 97 patients with CAD without HF (CAD+ HF-), 104 patients with HF (HF+), and 200 newborns from North-Western Poland using denaturing high-performance liquid chromatography (DHPLC), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and direct sequencing. Frequencies of AMPD1 C34T mutation, as well as novel A99G, G512A, IVS4-6delT, and C784T sequence alterations, were similar in the three groups, but 860T mutated allele was less frequent in the combined CAD+ HF- and HF+ groups than in the controls (1.7% vs. 4.3%, p=0.040). Heterozygous 34CT genotype was associated with lower (odds ratio [OR]=0.32, 95% confidence interval [CI] =0.13-0.81) and 860AT with higher (OR=13.7, 95%CI=1.6-118) prevalence of diabetes or hyperglycemia in relation to wild-type homozygotes. Abdominal obesity was more frequent in 860AT patients than in wild-type homozygotes and 34CT heterozygotes (86% vs. 40% vs. 29%, p<0.05). Nine genes containing polymorphisms linked with AMPD1 C34T mutation were found in the HapMap database. AMPD1 C34T nonsense mutation is associated with reduced prevalence of diabetes and obesity in patients with CAD or HF, but A860T substitution seems to exert opposite metabolic effects and should always be accounted for in the studies of the AMPD1 genotype.

[Xanthinuria type I as the cause of nephrolithiasis in 17-years old girl]. / Ksantynuria typu I jako przyczyna kamicy nerkowej u 17-letniej dziewczynki.

Classic xanthinuria is a rare metabolic defect concerning the final reactions of purine catabolism. There are two types of the disorder: type I results from xanthine dehydrogenase (XDH) deficiency, while type II is characterized by lack of both XDH and aldehyde oxidase activity. Both types are clinically similar and are characterized by elevated xanthine concentration in body fluids that can lead to xanthine crystallisation. The most common manifestation of the disease is urolithiasis, but in most cases xanthinuria remains asymptomatic and the diagnosis is accidental. In the paper we report the first case study of xanthinuria in Poland in a child presenting with urolithiasis. 17-years old female patient was diagnosed because of recurrent urinary lithiasis and hypouricemia was detected during routine tests. Plasma and urine concentrations of oxypurines were measured by high-performance liquid chromatography (HPLC) and showed typical features of xanthinuria: hypouricemia, hypouricosuria, xanthinuria and elevated plasma xanthine. The allopurinol loading test demonstrated type I xanthinuria. The presented case report supports that first symptoms of xanthinuria can appear at any age and this disorder should be considered during diagnosing urolithiasis.

Analysis of human CD36 gene sequence alterations in the oxidized low-density lipoprotein-binding region using denaturing high-performance liquid chromatography.

Denaturing high-performance liquid chromatography (DHPLC) has been employed as a prescreening tool to reduce the amount of DNA sequencing. It could be a simple and cost-effective screening method for mutations and polymorphisms in exons 4, 5, and 6 of the CD36 gene, which encode the protein region responsible for the removal of oxidized low-density lipoprotein. Genomic DNA was isolated from 306 Caucasian infants of Polish origin. Six single-nucleotide substitutions were detected by DHPLC and confirmed by direct sequencing. The A591T, G550A, and C572T alterations have not been described so far. Each of two nonsynonymous substitutions (Asp184Asn, Pro191Leu) was found in one subject (0.2% minor allele frequency). The results suggest that nonsynonymous alterations in the analyzed CD36 region are rare in Caucasians. DHPLC is a specific and cost-effective technique that may prove to be particularly useful for the identification of polymorphisms and mutations in the CD36 gene.

Lipoxygenase-derived hydroxyeicosatetraenoic acids--novel perioperative markers of early post-transplant allograft function?

BACKGROUND: Active metabolites of arachidonic acid (AA), eicosanoids, strongly influence renal homeostasis. The aims of this study were to measure perioperative variations in lipoxygenase (LOX)-derived 5-, 12- and 15-hydroxyeicosatetraenoic (HETE) acids levels, and to examine whether (i) dynamics of these eicosanoid generation changes during the first 5 min of renal allograft reperfusion, (ii) examined HETE acids may influence perioperative 20-HETE generation, and (iii) LOX HETE may serve as perioperative markers of early post-transplant allograft function. METHODS: Sixty-nine kidney recipients were divided into early, slow and delayed graft function (EGF, SGF and DGF, respectively) groups. Blood was taken directly before, and in the consecutive minutes of graft reperfusion. HETE concentrations were measured using liquid chromatography. Creatinine levels were measured during the perioperative period, as well as during follow-up visits (first post-transplant year). RESULTS: Our results demonstrated significant differences in the concentrations and dynamics of HETE changes between the examined groups. Moreover, observed changes in HETE concentrations were strongly associated with post-transplant graft function and perioperative 20-HETE synthesis. Application of cut-off limits for newly introduced markers, that is 71.72 ng/mL for 5-HETE(5), 12.3 ng/mL for 12-HETE△(5-0) and -6.1 ng/mL for 15-HETE△(5-0), resulted in 72.5-81.5% sensitivity and 50-54% specificity for SGF/DGF prediction. Moreover, mixed model analysis revealed that recipients classified according to results of 5-HETE(5) and 15-HETE△(5-0) significantly differ in 1-year post-transplant allograft function (P = 0.03 and P < 0.05, respectively), however, not in the frequency of acute rejections' episodes (P = 0.91 and P = 0.31, respectively). CONCLUSION: We hereby report that human kidney transplantations are accompanied by significant changes in LOX AA metabolism, which strongly influences and predicts early (1 year) post-transplant graft function.