295 research outputs found

    Oxidative stress in plants:update on molecular and cellular mechanisms

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    Free oxygen radicals regulate plasma membrane Ca2+- and K+-permeable channels in plant root cells

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    Free oxygen radicals are an irrefutable component of life, underlying important biochemical and physiological phenomena in animals. Here it is shown that free oxygen radicals activate plasma membrane Ca²⁺- and K⁺-permeable conductances in Arabidopsis root cell protoplasts, mediating Ca²⁺ influx and K⁺ efflux, respectively. Free oxygen radicals generate increases in cytosolic Ca²⁺ mediated by a novel population of nonselective cation channels that differ in selectivity and pharmacology from those involved in toxic Na⁺ influx. Analysis of the free oxygen radical-activated K⁺ conductance showed its similarity to the Arabidopsis root K⁺ outward rectifier. Significantly larger channel activation was found in cells responsible for perceiving environmental signals and undergoing elongation. Quenching root free oxygen radicals inhibited root elongation, confirming the role of radical-activated Ca²⁺ influx in cell growth. Net free oxygen radical-stimulated Ca²⁺ influx and K⁺ efflux were observed in root cells of monocots, dicots, C3 and C4 plants, suggesting conserved mechanisms and functions. In conclusion, two functions for free oxygen radical cation channel activation are proposed: initialization/amplification of stress signals and control of cell elongation in root growth.Vadim Demidchik, Sergey N. Shabala, Katherine B. Coutts, Mark A. Tester and Julia M. Davie

    Comparative study of quality of life, adverse effects after cytoreduction and HIPEC in stage IIIA-IIIC ovarian cancer

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    Nowadays cytorective surgery and HIPEC is the mainstay of management of advanced stages ovarian cancer. Study was conducted to assess the effectiveness of combined treatment in IIIA-IIIC ovarian cancer, its impact on quality of life. 37 patients of main group (CRS + HIPEC) were compared with 25 patients of control group (surgery + systemic chemotherapy). The quality of life was assessed with Medical Outcomes Study 36-Item Short Form Health Survey (SF-36). Comparative analysis of quality of life 6 months after treatment completion did not show significant statistical difference. Combination of cytoreduction with HIPEC improves quality of life in patients with ovarian cancer, is tolerated better and has less systemic toxicities than systemic chemotherapy

    The Role of Serum Neutrophil Gelatinase-associated Lipocalin in the Early Diagnosis of Nephropathy in Patients with Acute Alcohol Poisoning

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    AIM: In our study, we assessed the possibility of using the serum neutrophil gelatinase-associated lipocalin (NGAL) for the early detection of kidney damage in patients with acute alcohol poisoning (AAP). METHODS: The study included 89 patients and 30 healthy donors. All participants in the study were mostly represented by men (90%) aged between 20 and 40 years. The influence of alcohol poisoning severity was also taken into account in the study. The Human NGAL ELISA Kit was used for the quantitative detection of serum NGAL. We also evaluated the main laboratory indicators of kidney functions, including eGFR (calculated according to serum creatinine). RESULTS: We did not find a correlation between blood alcohol concentration and serum NGAL level; also, alcohol poisoning severity did not affect the NGAL values. The results of our study showed the possibility of using the serum NGAL in patients with AAP to detect the preclinical stage of reduced renal function, until the moment when it can be diagnosed with using only serum creatinine. CONCLUSION: We propose to consider an increase in eGFR together with an increase in serum NGAL in this group of patients as a stage, preceding nephropathy, even in the absence of clinical and laboratory signs of impaired renal function

    The Effect of Cu2+ on Ion Transport Systems of the Plant Cell Plasmalemma

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    Effect of supplemental Ca2+ on NaCl-stressed castor plants (Ricinus communis L.)

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    Greenhouse experiments were conducted to assess the effects of supplemental Ca2+ in salinised soil on germination and plant growth response of castor plant (Ricinus communis L. Var. Avani-31, Euphorbiaceae). NaCl amounting to 390 g was thoroughly mixed with soil of seven lots, of 100 kg each, to give electrical conductivity of 4.1 dS m–1. Further, Ca(NO3)2 × 4H20 to the quantity of 97.5, 195, 292.5, 390, 487.5, and 585 g was separately mixed with soil of six lots to give 1:0.25, 1:0.50, 1:0.75, 1:1, 1:1.25, and 1:1.50 Na+/Ca2+ ratios, respectively. The soil of the seventh lot contained only NaCl and its Na+/Ca2+ ratio was 1:0. Soil without addition of NaCl and Ca (NO3)2 × 4H20 served as control, with a 0:0 Na+/Ca2+ ratio. Salinity significantly retarded seed germination and plant growth, but the deleterious effects of NaCl on seed germination were ameliorated and plant growth was restored with Ca2+ supply at the critical level (1:0.25 Na+/Ca2+ ratio) to salinised soil. Supply of Ca2+ above the critical level further retarded seed germination and plant growth due to the increased soil salinity. Salt stress reduced N, P, K+ and Ca2+ content in plant tissues, but these nutrients were restored by addition of Ca2+ at the critical level to saline soil. In contrast, Na+ content in plant tissues significantly increased in response to salinity, but significantly decreased with increasing Ca2+ supply to saline soil. The results are discussed in terms of the beneficial effects of Ca2+ supply on the plant growth of Ricinus communis grown under saline conditions
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