83 research outputs found
Unexpected removal of the most neutral cationic pharmaceutical in river waters
Contamination of surface waters by pharmaceuticals is now widespread. There are few data on their environmental behaviour, particularly for those which are cationic at typical surface water pH. As the external surfaces of bacterio-plankton cells are hydrophilic with a net negative charge, it was anticipated that bacterio-plankton in surface-waters would preferentially remove the most extensively-ionised cation at a given pH. To test this hypothesis, the persistence of four, widely-used, cationic pharmaceuticals, chloroquine, quinine, fluphenazine and levamisole, was assessed in batch microcosms, comprising water and bacterio-plankton, to which pharmaceuticals were added and incubated for 21 days. Results show that levamisole concentrations decreased by 19 % in microcosms containing bacterio-plankton, and by 13 % in a parallel microcosm containing tripeptide as a priming agent. In contrast to levamisole, concentrations of quinine, chloroquine and fluphenazine were unchanged over 21 days in microcosms containing bacterio-plankton. At the river-water pH, levamisole is 28 % cationic, while quinine is 91–98 % cationic, chloroquine 99 % cationic and fluphenazine 72–86 % cationic. Thus, the most neutral compound, levamisole, showed greatest removal, contradicting the expected bacterio-plankton preference for ionised molecules. However, levamisole was the most hydrophilic molecule, based on its octanol–water solubility coefficient (K ow). Overall, the pattern of pharmaceutical behaviour within the incubations did not reflect the relative hydrophilicity of the pharmaceuticals predicted by the octanol–water distribution coefficient, D ow, suggesting that improved predictive power, with respect to modelling bioaccumulation, may be needed to develop robust environmental risk assessments for cationic pharmaceuticals
Recull de propostes per minimitzar l'impacte negatiu de gènere del sistema de teletreball a l'Ajuntament de Barcelona
Finançat amb el projecte "Impacto de GÉnero del TEletrabajo y rutinas de COnfinamiento: más allá de lo obvio" (Ref. SUPERACOVID19_2.2.IGETECO) i a través de l'Ajuntament de Barcelona pel Servei d'Estudi sobre propostes per minimitzar l'impacte negatiu de gènere del sistema de teletreball a l'Ajuntament de Barcelona (exp.20002682)El present document recull les propostes d'actuació contingues a l'estudi Propostes per minimitzar l'impacte negatiu de gènere del sistema de teletreball a l'Ajuntament de Barcelona realitzat pel Centre d'Estudis Sociològics sobre la Vida Quotidiana i el Treball (QUIT) de la Universitat Autònoma de Barcelona. L'emergència sanitària provocada per la Covid19 i el necessari confinament de la població per combatre la pandèmia ha significat, des del punt de vista de l'organització del treball, un canvi molt important cap a l'impuls de formes de treball a distància. Però aquest impuls del teletreball ha estat una resposta fruit de l'emergència, lògica davant la situació viscuda i, com a tal, no ha pogut ser planificada amb el temps i els mitjans necessaris
Natural and Semisynthetic Pentacyclic Triterpenes for Chronic Myeloid Leukemia Therapy: Reality, Challenges and Perspectives
Chronic myeloid leukemia (CML) is a neoplasm characterized by BCR-ABL1, an oncoprotein with vital role in leukemogenesis. Its inhibition by tyrosine kinase inhibitors represents the main choice of treatment. However, therapeutic failure is worrying given the lack of pharmacological options. Pentacyclic triterpenes are phytochemicals with outstanding antitumoral properties and have also been explored as a basis for the design of potential leads. In this review, we have gathered and discuss data regarding both natural and semisynthetic pentacyclic triterpenes applied to CML cell treatment. We found consistent evidence that the class of pentacyclic triterpenes in general exerts promising pro-apoptotic and antiproliferative activities in sensitive and resistant CML cells, and thus represents a rich source for drug development. We also analyze the predicted drug-like properties of the molecules, discuss the structural changes with biological implications and show the great opportunities this class represents, as well as the perspectives they provide on drug discovery for CML treatment
Calcium is the molecular switch shifting the phytosulfokine receptor 1 (PSKR1) from kinase to guanylate cyclase activity
Conference presentationMany plant responses are mediated by interactions between intracellular calcium and the second messenger cGMP formed by guanylate cyclases (GCs). Previously we identified a novel class of receptor-GCs containing the GC catalytic center embedded within the kinase domain and showed that the recombinant cytoplasmic domain of phytosulfokine receptor AtPSKR1 has both guanylate cyclase and kinase activity in vitro (Kwezi et al. 2011 J Biol Chem 286: 22580-8). We now show that physiological increases in calcium levels enhance GC activity of AtPSKR1 whereas these calcium levels reversibly inhibit kinase activity. In addition PSKR1 kinase activity is reduced in the presence of the GC product cGMP. Recombinant AtPSKR1 can undergo in vitro autophosphorylation and we have confirmed it has 14 phosphorylation sites in its cytoplasmic domain including 8 serine, 3 threonine and 3 tyrosine residues. Three phospho-serine residues at the juxta-membrane position were mutated to either mimic phosphorylation on or off states. Kinase activity was enhanced in the on mutant and suppressed in the off mutant while GC activity was unaffected suggesting calcium acts as a molecular switch of PSKR1- mediated signalling that can be modulated by the phosphorylation state. The challenge now lies in understanding how molecular interactions between the GC and kinase domains are capitalized on in the plant
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