Search results for "Lethal"

Acute toxicity and bioaccumulation of endosulfan in rotifer (Brachionus calyciflorus).

1991

Abstract 1. 1. The acute toxicity of endosulfan was determined for the freshwater rotifer Brachionus calyciflorus . 2. 2. The mean 24 hr lc 50 value for endosulfan was 5.15 ppm with a coefficient of variation of 14.7%. 3. 3. Rotifers were exposed at two sublethal concentrations (1.5–2.0 ppm) of endosulfan for bioaccumulation experiments, for an exposure time of 24, 48, 72 and 96 hr. The rotifers were fed with Nannochloris oculata (5 × 10 5 cell/ml). 4. 4. The highest accumulation of endosulfan was found 24 hr after the start of the exposure to 1.5 ppm of the toxicant. A steady-state concentration in rotifer was reached between 24–48 hr, followed by a gradual decrease until 96 hr.

Temperature-toxicity relationships of fluvalinate (synthetic pyrethroid) on Procambarus clarkii (Girard) under laboratory conditions.

1988

Cytotoxicity and antimitotic activity of Rhinella schneideri and Rhinella marina venoms.

2019

Abstract Ethnopharmacological relevance Rhinella schneideri and Rhinella marina are toad venoms distributed in different parts of the world, including Brazil, Columbia and amazon. Venoms extracted from different species have many clinical applications such as antimicrobial cardiotonics and treatment of cancer. Aim of the study; In this study, we aim to investigate the effect of venoms extracted from R. schneideri and R. marina on cancer cells and verify possible mechanism of action. Material and method Cytotoxicity analyses was performed using the resazurin reduction assay, where different concentrations of venoms were tested against sensitive CCRF-CEM and P-gp overexpressing ADR/CEM5000 le…

Tumor cell specific toxicity of Inula helenium extracts.

2006

The aim of the research program was to identify botanical extracts with antineoplastic activity. In this respect extracts prepared from Inula helenium roots showed a remarkable activity. As evidenced by the MTT assay, the Inula helenium extract revealed a highly selective toxicity toward four different tumor cell lines (HT-29, MCF-7, Capan-2 and G1), but a much lower toxicity against healthy human peripheral blood lymphocytes (PBLs) from two donors. The extract-induced death of tumor cells was studied extensively by electron microscopy. There was a remarkable similarity of morphological alterations observed in the four cell lines: patchy chromatin condensations, cytoplasmic vesiculation, sw…

Inhibition in vivo of the activity of botulinum neurotoxin A by small molecules selected by virtual screening

2012

To search for small molecular size inhibitors of botulinum neurotoxin A (BoNT/A) endopeptidase activity, we have screened the NCI library containing about 1 million structures against the substrate binding pocket of BoNT/A. Virtual screening (VS) was performed with the software Glide (Grid-based ligand docking energetics) and the findings were confirmed by AutoDock. Ten compounds were found that had favorable energetic and glide criteria and 5 of these compounds were selected for their ability to protect mice in vivo against a lethal dose of BoNT/A. Each compound was incubated at different molar excesses with a lethal dose of the toxin and then the mixture injected intravenously into mice. …

Use of molecular topology for the prediction of physico-chemical, pharmacokinetic and toxicological properties of a group of antihistaminic drugs

2002

We used molecular connectivity to search mathematical models for predicting physico-chemical (e.g. the partition coefficient, P), pharmacokinetic (e.g. the time of maximum plasma level, and toxicological properties (lethal dose, LD) for a group of antihistaminic drugs. The results obtained clearly reveal the high efficiency of molecular topology for the prediction of these properties. Randomization and cross-validation by use of leave-one-out tests were also performed in order to assess the stability and the prediction ability of the connectivity functions selected.

The human protein Hugl-1 substitutes for Drosophila lethal giant larvae tumour suppressor function in vivo

2004

Drosophila lethal giant larvae: (lgl), discs large (dlg) and scribble (scrib) are tumour suppressor genes acting in a common pathway, whose loss of function leads to disruption of cell polarity and tissue architecture, uncontrolled proliferation and growth of neoplastic lesions. Mammalian homologues of these genes are highly conserved and evidence is emerging concerning their role in cell proliferation control and tumorigenesis in humans. Here we investigate the functional conservation between Drosophila lethal giant larvae and its human homologue Hugl-1(Llgl1). We first show that Hugl-1 is lost in human solid malignancies, supporting its role as a tumour suppressor in humans. Hugl-1 expres…

Procedimento per la sintesi di esosomi contenenti proteine da shock termico e loro uso per il trattamento della atrofia muscolare e della cachessia

2018

Sequence of the new Drosophila melanogaster small heat-shock-related gene, lethal(2) essential for life [l(2)efl], at locus 59F4,5.

1995

Abstract In this study, we report the molecular cloning of a novel Drosophila melanogaster small heat-shock (HS)-homologous gene, l(2)efl, identified on the right arm of the second chromosome at locus 59F4,5. We describe the temporal expression of l(2)efl in the wild-type and present its structure. The deduced amino-acid sequence of the Efl protein shows significant homology to all known small HS proteins identified in Drosophila and vertebrates, and to mammalian α-crystallin.

Pathogenicity of intrathoracically administrated Bacillus thuringiensis spores in Blatta orientalis.

2006

Abstract The ability of Bacillus thuringiensis to produce septicaemia in Periplaneta americana and Blatta orientalis has been investigated. Spores and crystals from several wild-type strains as well as spores of a B. thuringiensis crystal-deficient mutant, were first orally administrated at high doses, and no significant mortality was recorded. Intrathoracic injection of spore suspensions in P. americana revealed that this species is not very susceptible to B. thuringiensis spores. B. orientalis , by contrast, was found to be very susceptible to B. thuringiensis , with a LD 50 of about 35,000 spores, that is similar to that reported on Lepidoptera challenged with parenterally injected B. th…