34 research outputs found

    A Novel Biosensor for Evaluation of Apoptotic or Necrotic Effects of Nitrogen Dioxide during Acute Pancreatitis in Rat

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    The direct and accurate estimation of nitric dioxide levels is an extremely laborious and technically demanding procedure in the molecular diagnostics of inflammatory processes. The aim of this work is to demonstrate that a stop-flow technique utilizing a specific spectroscopic biosensor can be used for detection of nanomolar quantities of NO2 in biological milieu. The use of novel compound cis-[Cr(C2O4)(AaraNH2)(OH2)2]+ increases NO2 estimation accuracy by slowing down the rate of NO2 uptake. In this study, an animal model of pancreatitis, where nitrosative stress is induced by either 3g/kg bw or 1.5 g/kg bw dose of l-arginine, was used. Biochemical parameters and morphological characteristics of acute pancreatitis were monitored, specifically assessing pancreatic acinar cell death mode, NO2 generation and cellular glutathione level. The severity of the process correlated positively with NO2 levels in pancreatic acinar cell cytosol samples, and negatively with cellular glutathione levels

    Determination of adenine nucleotides and their metabolites in human saliva.

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    The profile and normal concentrations of nucleotide metabolites in human saliva and reproducibility of these determinations were analyzed. Samples of human saliva collected from healthy individuals at weekly intervals, were deproteinized and analysed for the content of adenine nucleotides and their metabolites by reversed-phase HPLC. Initial ATP, hypoxanthine and uric acid concentrations were 0.52 ± 0.15 ΌM, 1.91 ± 0.37 ΌM and 184 ± 22 ΌM respectively. A substantial individual variation persisted within 3 weeks of sampling excepted hypoxanthine which showed some unrelated variations. Determination of nucleotides and their catabolites in saliva due to its simplicity and reproducibility, may be of clinical value in diagnosis of local or systemic disorders

    Dual effect of 2-methoxyestradiol on cell cycle events in human osteosarcoma 143B cells.

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    We have demonstrated for the first time that the steroid metabolite, 2-methoxyestradiol (2-ME) is a powerful growth inhibitor of human osteosarcoma 143 B cell line by pleiotropic mechanisms involving cell cycle arrest at two different points and apoptosis. The ability of 2-ME to inhibit cell cycle at the respective points has been found concentration dependent. 1 ÎŒM 2-ME inhibited cell cycle at G1 phase while 10 ÎŒM 2-ME caused G2/M cell cycle arrest. As a natural estrogen metabolite 2-ME is expected to perturb the stability of microtubules (MT) in vivo analogously to Taxol - the MT binding anticancer agent. Contrary to 2-ME, Taxol induced accumulation of osteosarcoma cells in G2/M phase of cell cycle only. The presented data strongly suggest two different mechanisms of cytotoxic action of 2-ME at the level of a single cell

    Activation of hydrogen peroxide to peroxytetradecanoic acid is responsible for potent inhibition of protein tyrosine phosphatase CD45.

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    Hydrogen peroxide induces oxidation and consequently inactivation of many protein tyrosine phosphatases. It was found that hydrogen peroxide, in the presence of carboxylic acids, was efficiently activated to form even more potent oxidant - peroxy acid. We have found that peroxytetradecanoic acid decreases the enzymatic activity of CD45 phosphatase significantly more than hydrogen peroxide. Our molecular docking computational analysis suggests that peroxytetradecanoic acid has a higher binding affinity to the catalytic center of CD45 than hydrogen peroxide

    hmSOD1 gene mutation‐induced disturbance in iron metabolism is mediated by impairment of Akt signalling pathway

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    Abstract Background Recently, skeletal muscle atrophy, impairment of iron metabolism, and insulin signalling have been reported in rats suffering from amyotrophic lateral sclerosis (ALS). However, the interrelationship between these changes has not been studied. We hypothesize that an impaired Akt–FOXO3a signalling pathway triggers changes in the iron metabolism in the muscles of transgenic animals. Methods In the present study, we used transgenic rats bearing the G93A hmSOD1 gene and their non‐transgenic littermates. The study was performed on the muscles taken from animals at three different stages of the disease: asymptomatic (ALS I), the onset of the disease (ALS II), and the terminal stage of the disease (ALS III). In order to study the molecular mechanism of changes in iron metabolism, we used SH‐SY5Y and C2C12 cell lines stably transfected with pcDNA3.1, SOD1 WT and SOD1 G93A, or FOXO3a TM‐ER. Results A significant decrease in P‐Akt level and changes in iron metabolism were observed even in the group of ALS I animals. This was accompanied by an increase in the active form of FOXO3a, up‐regulation of atrogin‐1, and catalase. However, significant muscle atrophy was observed in ALS II animals. An increase in ferritin L and H was accompanied by a rise in PCBP1 and APP protein levels. In SH‐SY5Y cells stably expressing SOD1 or SOD1 G93A, we observed elevated levels of ferritin L and H and non‐haem iron. Interestingly, insulin treatment significantly down‐regulated ferritin L and H proteins in the cell. Conversely, cells transfected with small interfering RNA against Akt 1, 2, 3, respectively, showed a significant increase in the ferritin and FOXO3a levels. In order to assess the role of FOXO3a in the ferritin expression, we constructed a line of SH‐SY5Y cells that expressed a fusion protein made of FOXO3a fused at the C‐terminus with the ligand‐binding domain of the oestrogen receptor (TM‐ER) being activated by 4‐hydroxytamoxifen. Treatment of the cells with 4‐hydroxytamoxifen significantly up‐regulated ferritin L and H proteins level. Conclusions Our data suggest that impairment of insulin signalling and iron metabolism in the skeletal muscle precedes muscle atrophy and is mediated by changes in Akt/FOXO3a signalling pathways

    Potential Health Benefits of Olive Oil and Plant Polyphenols

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    Beneficial effects of natural plant polyphenols on the human body have been evaluated in a number of scientific research projects. Bioactive polyphenols are natural compounds of various chemical structures. Their sources are mostly fruits, vegetables, nuts and seeds, roots, bark, leaves of different plants, herbs, whole grain products, processed foods (dark chocolate), as well as tea, coffee, and red wine. Polyphenols are believed to reduce morbidity and/or slow down the development of cardiovascular and neurodegenerative diseases as well as cancer. Biological activity of polyphenols is strongly related to their antioxidant properties. They tend to reduce the pool of reactive oxygen species as well as to neutralize potentially carcinogenic metabolites. A broad spectrum of health-promoting properties of plant polyphenols comprises antioxidant, anti-inflammatory, anti-allergic, anti-atherogenic, anti-thrombotic, and anti-mutagenic effects. Scientific studies present the ability of polyphenols to modulate the human immune system by affecting the proliferation of white blood cells, and also the production of cytokines or other factors that participate in the immunological defense. The aim of the review is to focus on polyphenols of olive oil in context of their biological activities

    Effect of pentoxifylline on proteinuria, markers of tubular injury and oxidative stress in non-diabetic patients with chronic kidney disease - placebo controlled, randomized, cross-over study

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    Background: Inhibition of the renin-angiotensin-aldosterone system (RAAS) with angiotensin converting enzyme inhibitors (ACEI) and/or angiotensin II subtype 1 receptor antagonists (ARB) is a common strategy used in the management of patients with chronic kidney disease (CKD). However, there is no universal therapy that can stop progression of CKD. Pentoxifylline (PTE) is a non-specific phosphodiesterase inhibitor with anti-inflammatory properties. It has been reported to have promising effects in CKD treatment. Methods: In a placebo-controlled, randomized, cross-over study we evaluated the influence of PTE (1200 mg/day) added to RAAS blockade on proteinuria, surrogate markers of tubular injury and oxidative stress-dependent products in 22 non-diabetic patients with proteinuria (0.4-4.3 g per 24h) with normal or declined kidney function [eGFR 37-178 mL/min]. In an eight-week run-in period, therapy using ACEI and/or ARB was adjusted to achieve a blood pressure below 130/80 mm Hg. Next, patients were randomly assigned to one of two treatment sequences: PTE/washout/placebo or placebo/washout/PTE. Clinical evaluation and laboratory tests were performed at the randomization point and after each period of the study. Results: The PTE therapy reduced proteinuria (by 26%) as compared to placebo. There were no differences in α1-microglobulin, urine excretion of N-acetyl-ÎČ-d-glucosaminidase (NAG), hsCRP, the urinary excretion of 15-F2t-isoprostane, blood pressure (BP), eGFR and serum creatinine between the PTE and placebo groups. Conclusion: Pentoxifylline may decrease proteinuria in non-diabetic patients with CKD
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