| 1. |
- Diez-Quijada, Leticia, et al.
(författare)
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In Vitro Toxicity Evaluation of Cyanotoxins Cylindrospermopsin and Microcystin-LR on Human Kidney HEK293 Cells
- 2022
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Ingår i: Toxins. - : MDPI. - 2072-6651. ; 14:7
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Tidskriftsartikel (refereegranskat)abstract
- Cyanotoxins are secondary metabolites produced by different types of cyanobacteria. Among them, Cylindrospermopsin (CYN) and Microcystins (MCs) stand out due to their wide geographical distribution and toxicity in various organs, including the kidney, which is involved in their distribution and elimination. However, the renal toxicity caused by CYN and MCs has hardly been studied. The aim of this work was to assess the cytotoxicity effects caused by CYN and MC-LR in the renal cell line HEK293, and for the first time, the influence of CYN on the gene expression of selected genes in these cells by quantitative real-time PCR (qRT-PCR). CYN caused an upregulation in the gene expression after exposure to the highest concentration (5 mu g/mL) and the longest time of exposure (24 h). Moreover, shotgun proteomic analysis was used to assess the molecular responses of HEK293 cells after exposure to the individuals and combinations of CYN + MC-LR. The simultaneous exposure to both cyanotoxins caused a greater number of alterations in protein expression compared to single toxins, causing changes in the cellular, lipid and protein metabolism and in protein synthesis and transport. Further studies are needed to complete the toxicity molecular mechanisms of both CYN and MC-LR at the renal level.
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| 2. |
- Dorlo, Thomas P C, et al.
(författare)
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Translational pharmacokinetic modelling and simulation for the assessment of duration of contraceptive use after treatment with miltefosine.
- 2012
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Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 67:8, s. 1996-2004
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Use of miltefosine in the treatment of visceral leishmaniasis (VL) is hampered by its potential teratogenicity. The duration of adequate contraceptive cover in females of child-bearing potential after cessation of a potentially teratogenic drug therapy remains debated. The objective of this study was to provide a rational approach to suggest durations of contraceptive cover for various miltefosine regimens.METHODS: A human reproductive safety threshold exposure limit was derived using animal-to-human dose conversion. Pharmacokinetic (PK) data for miltefosine in females are lacking; a previously developed population PK model and a comprehensive anthropometric dataset were used to simulate PK data for Indian female VL patients receiving miltefosine for 5, 7, 10 or 28 days. Probability of supra-threshold miltefosine exposure was used to evaluate adequate durations of post-treatment contraceptive cover for the various regimens.RESULTS: PK data were simulated for 465 treated Indian female VL patients of child-bearing potential with a median age of 25 years (IQR 16-31 years) and median weight of 38 kg (IQR 34-42 kg). From animal reproductive toxicity studies, a human reproductive safety threshold exposure limit was derived of 24.5 μg · day/mL. Probability of 'unprotected' supra-threshold miltefosine exposure was very low (<0.2%) for a post-treatment contraceptive cover period of 4 months for the standard 28 day regimen, and of 2 months for the shorter regimens.CONCLUSIONS: To our knowledge, this is the first study providing rational suggestions for contraceptive cover for a teratogenic drug based on animal-to-human dose conversion. For the 28 day miltefosine regimen, post-treatment contraceptive cover may be extended to 4 months, whereas for all shorter regimens 2 months may be adequate.
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| 3. |
- Oliveira, Flavio, et al.
(författare)
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Physiological and Metabolic Responses of Marine Mussels Exposed to Toxic Cyanobacteria Microcystis aeruginosa and Chrysosporum ovalisporum
- 2020
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Ingår i: Toxins. - : MDPI. - 2072-6651. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Toxic cyanobacterial blooms are a major contaminant in inland aquatic ecosystems. Furthermore, toxic blooms are carried downstream by rivers and waterways to estuarine and coastal ecosystems. Concerning marine and estuarine animal species, very little is known about how these species are affected by the exposure to freshwater cyanobacteria and cyanotoxins. So far, most of the knowledge has been gathered from freshwater bivalve molluscs. This work aimed to infer the sensitivity of the marine mussel Mytilus galloprovincialis to single as well as mixed toxic cyanobacterial cultures and the underlying molecular responses mediated by toxic cyanobacteria. For this purpose, a mussel exposure experiment was outlined with two toxic cyanobacteria species, Microcystis aeruginosa and Chrysosporum ovalisporum at 1 x 10(5) cells/mL, resembling a natural cyanobacteria bloom. The estimated amount of toxins produced by M. aeruginosa and C. ovalisporum were respectively 0.023 pg/cell of microcystin-LR (MC-LR) and 7.854 pg/cell of cylindrospermopsin (CYN). After 15 days of exposure to single and mixed cyanobacteria, a depuration phase followed, during which mussels were fed only non-toxic microalga Parachlorella kessleri. The results showed that the marine mussel is able to filter toxic cyanobacteria at a rate equal or higher than the non-toxic microalga P. kessleri. Filtration rates observed after 15 days of feeding toxic microalgae were 1773.04 mL/ind.h (for M. aeruginosa), 2151.83 mL/ind.h (for C. ovalisporum), 1673.29 mL/ind.h (for the mixture of the 2 cyanobacteria) and 2539.25 mL/ind.h (for the non-toxic P. kessleri). Filtering toxic microalgae in combination resulted in the accumulation of 14.17 ng/g dw MC-LR and 92.08 ng/g dw CYN. Other physiological and biochemical endpoints (dry weight, byssus production, total protein and glycogen) measured in this work did not change significantly in the groups exposed to toxic cyanobacteria with regard to control group, suggesting that mussels were not affected with the toxic microalgae. Nevertheless, proteomics revealed changes in metabolism of mussels related to diet, specially evident in those fed on combined cyanobacteria. Changes in metabolic pathways related with protein folding and stabilization, cytoskeleton structure, and gene transcription/translation were observed after exposure and feeding toxic cyanobacteria. These changes occur in vital metabolic processes and may contribute to protect mussels from toxic effects of the toxins MC-LR and CYN.
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