Search results for "TOXICITY"

Corrigendum to “Zinc oxide nanoparticles mediated cytotoxicity, mitochondrial membrane potential and level of antioxidants in presence of melatonin” …

2021

The biogeochemical cycle of mercury in the Augusta Bay

2014

Mercurial, the metaphor for volatile unpredictable behavior, aptly reflects the complexities of one of the most insidiously interesting and scientifically challenging biogeochemical cycles at the Earth’s surface. At the base of this toxic metal cycle there is the conversion between the different Hg chemical species, in which the balance between the reduced and oxidized forms depends primary on redox system conditions. The potential risks of human exposure to Hg, especially in the form of monomethylmercury (MMHg), particularly prenatally, and the potential deleterious ecological consequences from localized to global scale Hg pollution, have given much impetus to mercury studies and regulator…

Manganese interferes with calcium, perturbs ERK signaling, and produces embryos with no skeleton.

2011

Manganese (Mn) has been associated with embryo toxicity as it impairs differentiation of neural and skeletogenic cells in vertebrates. Nevertheless, information on the mechanisms operating at the cellular level remains scant. We took advantage of an amenable embryonic model to investigate the effects of Mn in biomineral formation. Sea urchin (Paracentrotus lividus) embryos were exposed to Mn from fertilization, harvested at different developmental stages, and analyzed for their content in calcium (Ca), expression of skeletogenic genes, localization of germ layer markers, and activation of the extracellular signal-regulated kinase (ERK). By optical and immunofluorescence microscopy, we found…

Modeling the mobility of glyphosate from two contrasting agricultural soils in laboratory column experiments

2019

Glyphosate (GLP) currently is one of the most widely used herbicides worldwide. The persistence of GLP and its major metabolite, aminomethylphosphonic acid (AMPA) in the environment has been described by other authors. This study was aimed at comparing the GLP and AMPA behavior in sandy and loamy sand soils after spiking with enhanced (445 µg g−1) concentrations of GLP in herbicide KLINIK® (Nufarm, Austria) and bioaugmentation followed by 40 days weathering and a consistent three-stage leaching in a laboratory column experiment. Soil samples were obtained from mineral topsoil (0–10 cm) within former agricultural lands where soil parent material was formed by glacigenic deposits. The total a…

Modificazioni indotte dal metilmercurio sugli emociti dell’ascidia Styela plicata

2011

O6-methylguanine DNA methyltransferase and p53 status predict temozolomide sensitivity in human malignant glioma cells

2006

Temozolomide (TMZ) is a methylating agent which prolongs survival when administered during and after radiotherapy in the first-line treatment of glioblastoma and which also has significant activity in recurrent disease. O6-methylguanine DNA methyltransferase (MGMT) is a DNA repair enzyme attributed a role in cancer cell resistance to O6-alkylating agent-based chemotherapy. Using a panel of 12 human glioma cell lines, we here defined the sensitivity to TMZ in acute cytotoxicity and clonogenic survival assays in relation to MGMT, mismatch repair and p53 status and its modulation by dexamethasone, irradiation and BCL-X(L). We found that the levels of MGMT expression were a major predictor of T…

Citotoxicity of four types of resins used for removable denture bases: in vitro comparative analysis

2009

Objective: To compare the cytotoxicity of four types of resins used for manufacturing denture bases. Method and Materials: 9 disk-shaped samples of four resin (two heat-polymerized, one auto-polymerized, and one light-polymerized), 9 samples of glass (negative control) and 9 samples of lead (positive control) were made according to the manufacturer instructions. The materials were tested by contact with BALB/C 3T3 fibroblast cells. Each sample was tested after 24, 48 and 72 hours. The cellular vitality was verified through spectrophotometric analysis of the solution where the colour is directly related to the amount of metabolically active and living cells. The results were analyzed through…

Adaptogens in chemobrain (Part III): Antitoxic effects of plant extracts towards cancer chemotherapy-induced toxicity - transcriptome-wide microarray…

2019

Abstract Background Toxicity of chemotherapeutics is a serious problem in cancer therapy. Adaptogens are known to increase adaptability and survival organisms. Aim The aim of this study was to assess the effects of selected adaptogenic herbal extracts on FEC (fixed combination of 5-fluorouracil, epirubicin and cyclophosphamide) induced changes in transcriptome-wide microarray profiles of neuroglia cells. Another task of the study was to identify those genes, which are associated with FEC-induced hepato-, cardio– and nephrotoxicity to predict potential effects of andrographolide (AND), Andrographis herb, Eleutherococcus roots genuine extracts (ES), their fixed combination (AE) and the combin…

Adaptogens in chemobrain (Part I): Plant extracts attenuate cancer chemotherapy-induced cognitive impairment – Transcriptome-wide microarray profiles…

2019

Abstract Background Cancer chemotherapy-induced cognitive impairments are presumably associated with undesirable effects of chemotherapy on physiological functions of brain cells. Adaptogens are natural compounds or plant extracts increasing an organism's adaptability and survival in stress. They exhibited neuroprotective effects and increased cognitive functions in clinical studies in human beings. Hypothesis We hypothesized that selected adaptogenic plant extracts attenuate or prevent cancer chemotherapy-induced cognitive impairments. Aim We assessed the effects of selected adaptogenic herbal extracts on FEC (fixed combination 5-fluorouracil, epirubicin and cyclophosphamide) induced chang…

Cytokine-mediated regulation of monocyte/macrophage cytotoxicity in human immunodeficiency virus-1 infection.

1992

Monocyte/macrophage-mediated tumor cytotoxicity was studied in patients infected with human immunodeficiency virus-1 (HIV-1) at various stages [Center for disease control (CDC) classification] of the disease. using the P-815 tumor cell line as target cells, the results demonstrated reduced monocyte/macrophage cytotoxicity early in HIV-1-related disease (CDCIII, P0.01). This cellular dysfunction sustained during the progression of the disease. Evidence could be presented that neither exogenous application of macrophage-stimulating cytokines (e.g. interferons) nor their endogenous induction in vitro restored monocyte/macrophage cytotoxicity. However, enhanced tumor necrosis factor (TNF)-alpha…