Environmental pollution by antibiotics poses a potential ecological risk to aquatic photosynthetic organisms. In the present study, toxic effects of erythromycin on PSI and PSII were investigated in cyanobacteria culture medium of Microcystis aeruginosa. The activity and electron transport of both photosystems were affected by erythromycin in a concentrationdependent manner. The quantum yield of PSII (YII) was reduced at 0.1 mg L-1 of erythromycin, while the quantum yield of PSI (YI) significantly decreased at concentration of 5-25 mg L-1. The decline of YII was accompanied by an increase of nonregulated energy dissipation (YNO). At 10 mg L-1 of erythromycin, YII decreased by 55%, while YNO increased by 18%. The decrease of YI induced by erythromycin was caused by donor-side limitation of PSI (YND). YND was markedly enhanced with elevated erythromycin concentration. At 10 mg L-1 of erythromycin, YI and YNA (PSI acceptor-side limitation) decreased by 8 and 82%, respectively, while YND rose by 314%. The quantum yield of cyclic electron flow increased significantly at 0.1-1 mg L-1 of erythromycin; it decreased but remained higher than that of the control at 5-25 mg L-1 of erythromycin. The contribution of cyclic electron flow to YI, and to linear electron flow rose significantly with the increasing erythromycin concentration. The maximum values of electron transport rates in PSII and PSI decreased by 71 and 24.3%, respectively, at 25 mg L-1 of erythromycin. Compared with the untreated control, the light saturation of PSII and PSI decreased significantly with increasing erythromycin concentration. We showed that concentrations of erythromycin >- 5 mg L-1 could exert acute toxicity to cyanobacteria, whereas the chronic toxicity caused by concentrations of ng or μg L-1 needs further research., C.-N. Deng, D.-Y. Zhang, X.-L. Pan., and Obsahuje bibliografii
The aim of this study was to determine the impact of increased copper contents on selected physiological processes in oneyear-old Pinus sylvestris L. needles from a former German timber storage area in Warcino Forest District, a subject to an environmental quality survey. Samples were collected from the area with the high copper content in the soil. The control area was a nearby pine tree stand showing unimpeded growth. The significant growth inhibition was found in dwarf shoots and whole needles, increased water content, and reduced dry mass were also observed. The chlorophyll content was lowered, while 20% higher electrolyte leakage was found. Chlorophyll a fluorescence indicated only higher values of the nonphotochemical quenching in P. sylvestris from the Cu-site. Significant differences were shown in the rate of gas exchange measured by changes in carbon dioxide or oxygen concentration. The intensity of photosynthesis in needles of P. sylvestris from the Cu-site measured by CO2 uptake was considerably higher than that of oxygen production. The rate of respiration in the needles from the Cu-site measured by the amount of released CO2 was higher only by 15%, while according to O2 consumed, the rate increased by 30% in relation to the control. Our results suggest that the copper accumulation in P. sylvestris needles affected the morphology and physiology of the studied organs., K. Możdżeń, T. Wanic, G. Rut, T. Łaciak, A. Rzepka., and Obsahuje bibliografii
Thioacetamide (TAA) is widely used in the production of drugs, pesticides and dyeing auxiliaries. Moreover, it is a chemical that can cause liver damage and cancer. TAA has recently been identified to cause bone damage in animal models. However, the type of bone damage that TAA causes and its potential pathogenic mechanisms remain unclear. The toxic effects of TAA on the femurs of New Zealand white rabbits and the underlying toxicity mechanism were investigated in this study. Serum samples, the heart, liver, kidney and femurs were collected from rabbits after intraperitoneal injection of TAA for 5 months (100 and 200 mg/kg). The New Zealand white rabbits treated with TAA showed significant weight loss and femoral shortening. The activities of total bilirubin, total bile acid and gamma-glutamyl transpeptidase in the serum were increased following treatment with TAA. In addition, the cortical bone became thinner, and the trabecular thickness decreased significantly in TAA-treated rabbits, which was accompanied by significantly decreased mineral density of the cortical and trabecular bone. Moreover, there was a significant decrease in modulus of elasticity and maximum load on bone stress in TAA-treated rabbits. The western blotting results showed that the expression of phosphorylated (p)-p38 and p-ERK in femur tissues of rabbits were increased after TAA administration. Collectively, these results suggested that TAA may lead to femoral damage in rabbits by activating the p38/ERK signaling pathway.
We summarize the contemporary understanding of the effects of metal stress on various photosynthetic processes in photoautotrophic organisms and of the defence strategies employed by these organisms to avoid such stress. Cadmium is in the centre of interest of this review, as a non-essential element and important environmental pollutant, but Al, Pb, Hg, As, Cu, and Zn are also considered. Toxic metal ions pollute the environment through anthropogenic activities and affect the quality of plant crop. They represent one of the main abiotic stress factors influencing the health of plants and, as a secondary effect, of animals including man. The review summarizes the generally accepted answers to the questions: How do the toxic metal ions enter the photosynthetic organisms? How are they accumulated in plants? Which mechanisms do plants develop to tolerate metal stress and protect themselves? and T. Kučera, H. Horáková, A. Šonská.
Docetaxel je cytostatikum užívané v adjuvantní, neoadjuvatní i paliativní léčbě karcinomu prsu. Je podáván jako monoterapie či jako součást kombinovaných režimů. Taxany obecně spolu s antracykliny patří mezi nejefektivnější chemoterapeutika využívané v léčbě karcinomu prsu. Zařazení docetaxelu do léčebného schématu karcinomu prsu přineslo zlepšení celkového přežití a prodloužení období bez nemoci u pacientek léčených adjuvantně a větší procento léčebných odpovědí, prodloužení doby do progrese a celkového přežití při léčbě paliativní (1, 2, 3, 4, 5). Při využívání docetaxelu v léčbě je potřeba mít na paměti, že se jedná o chemoterapeutikum s nezanedbatelnými nežádoucími účinky. Cílem naší retrospektivní studie bylo vyhodnocení akutní toxicity při léčbě režimy s docetaxelem a zvážení možností léčby akutní toxicity., Docetaxel is a cytostatic drug used in adjuvant, neoadjuvant as well as palliative treatment of breast cancer. It is administered as monotherapy or as part of combination regimens. Taxanes along with anthracyclines are among the most efficacious chemotherapeutic drugs used in the treatment of breast cancer. Inclusion of docetaxel in the therapeutic regimen for breast cancer has resulted in improved overall survival and extended disease-free interval in patients treated with adjuvant therapy and in a greater proportion of therapeutic responses as well as extended time-to-progression and overall survival with palliative therapy (1, 2, 3, 4, 5). It must be kept in mind that, when used for treatment, docetaxel is a chemotherapeutic drug with non-negligible adverse effects. The aim of our retrospective study was to evaluate acute toxicity of therapeutic regimens with docetaxel and to consider the options for the treatment of acute toxicity., Kateřina Krošláková, Milan Kohoutek, Markéta Pospíšková, and Literatura
The aim of the study was to examine the potential impacts of bisphenol A (BPA) and its analogues BPB, BPF, and BPS on mice TM3 Leydig cells, with respect to basal cell viability parameters such as metabolic activity, cell membrane integrity, and lysosomal activity after 48-h exposure. In addition, monitoring of potential bisphenol´s actions included evaluation of ROS production and gap junctional intercellular communication (GJIC) complemented by determination of testosterone secretion. Obtained results revealed significant inhibition in mitochondrial activity started at 10 µg/ml of bisphenols after 48-h exposure. Cell membrane integrity was significantly decreased at 5 µg/ml of BPA and BPF and 10, 25, and 50 µg/ml of BPA and BPS. The lysosomal activity was significantly affected at 10, 25, and 50 µg/ml of applied bisphenols. A significant overproduction of ROS was recorded mainly at 5 and 10 µg/ml of tested compounds. In addition, significant inhibition of GJIC was observed at 5 µg/ml of BPB followed by a progressive decline at higher applied doses. In the case of testosterone production, a significant decline was confirmed at 10, 25 and 50 µg/ml.
The toxicity of cadmium and zinc at concentrations ranging from 0.1 to 100 µg/l was investigated against the activity of Diplostomum spathaceum (Rudolphi, 1819) cercariae. Over a 24 h exposure period a significant reduction in cercarial activity occurred in solutions of cadmium, zinc, and a mixture of cadmium and zinc at all concentrations. Reduced cercarial activity also occurred in all toxicant solutions compared with controls after only 6 h exposure indicating that cercariae were vulnerable during the period of maximum cercarial infectivity (0-5 h). The mechanisms of metal toxicity and their importance to parasite transmission are discussed.
Toxická epidermální nekrolýza je vzácné, akutní, život ohrožující onemocnění projevující se rozsáhlým odlučováním epidermis a slizničních povrchů. Jde o závažnou nežádoucí reakci na podávané léky, nejčastěji antibiotika, antikonvulziva či nesteroidní antirevmatika. Jako první ji popsal skotský dermatolog Alan Lyell v roce 1956, proto je též nazývána Lyellův syndrom. Mortalita tohoto onemocnění je vysoká, proto je klíčová včasná diagnostika a neodkladné zahájení adekvátní péče o pacienta. Jedná se o vzácné onemocnění s velmi malou incidencí a závažnou prognózou, což značně ztěžuje provedení velkých randomizovaných klinických studií. Je tedy obtížné hodnotit efektivitu jednotlivých terapeutických možností. Jako nejperspektivnější se prozatím jeví nitrožilní podávání imunoglobulinů se zřejmým zlepšením klinického stavu pacienta, dobrou tolerancí a minimálními vedlejšími nežádoucími účinky. Nové experimentální postupy se snaží hledat cestu terapie cíleným ovlivněním granulyzinu jakožto hlavního cytotoxického mediátoru. Klíčová slova: anamnéza – apoptóza keratinocytů – cyklosporin A – granulyzin – hodnocení SCORTEN – intravenózní imunoglobuliny – interdisciplinární péče – kortikosteroidy – Nikolského fenomén – plazmaferéza – poléková reakce – Stevensův-Johnsonův syndrom – toxická epidermální nekrolýza, Toxic epidermal necrolysis is a rare, acute and life-threatening disorder manifested by extensive separation of the epidermis and mucosal surfaces. It is a serious adverse response to administered drugs, mostly antibiotics, anticonvulsants or NSAIDs. First described by Scottish dermatologist Alan Lyell in 1956, it is also known as Lyell’s syndrome. Mortality of the disease is high, therefore its early diagnosis is crucial and immediate initiation of appropriate patient care necessary. It is a rare disease with a very low incidence and serious prognosis, which is a considerable hindrance to undertaking large randomized clinical studies. It is therefore difficult to evaluate the effectiveness of various therapeutic options. As the most promising so far appears the administration of intravenous immunoglobulins, apparently reaching improvement in the clinical condition of the patient, with a good tolerances and minimal side adverse effects. New experimental techniques endeavour to seek a way to the therapy through targeted influencing of granulysin as the major cytotoxic mediator. Key words: adverse drug reaction – corticosteroids – cyclosporine A – granulysin – intravenous immunoglobulins – interdisciplinary team care – keratinocyte apoptosis – medical history – Nikolsky´s sign – plasmapheresis – SCORTEN score – Stevens-Johnson syndrome – toxic epidermal necrolysis, and Dina Odarčenková, Milan Kvapil