Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
Environ Pollut ; 305: 119277, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35427676

RESUMO

Microplastic pollution affects freshwater and marine biota worldwide, microplastics occurring even inside the organisms. With highly variable effects, from physical damage to toxicity of plastic compounds, microplastics are a potential threat to the biodiversity, community composition and organisms' health. This emerging pollutant could overstress diadromous species, which are exposed to both sea and river water in their life cycle. Here we have quantified microplastics in young European eel Anguilla anguilla, a critically endangered catadromous fish, entering three rivers in southwestern Bay of Biscay. River water, sediments and seawater were also analysed for microplastics. The microplastic type was identified using Fournier-Transform Infrared spectroscopy and then searched for their hazard potential at the European Chemical Agency site. Both riverine and sea microplastic pollution were predictors of eels' microplastic profile (types of microplastics by shape and colour): A. anguilla juveniles entering European rivers already carry some marine microplastics and acquire more from river water. Potentially hazardous plastic materials were found from eels, some of them dangerous for aquatic life following the European Chemical Agency. This confirms microplastics as a potential threat for the species. Between-rivers differences for microplastics profiles persistent over years highlight the convenience of analysing and preventing microplastics at a local spatial scale, to save diadromous species from this stressor. Since the origin of microplastics present in glass eels seems to be dual (continental + seawater), new policies should be promoted to limit the entry of microplastics in sea and river waters.


Assuntos
Anguilla , Poluentes Químicos da Água , Animais , Ecossistema , Monitoramento Ambiental , Microplásticos , Plásticos , Rios , Água
2.
Mar Pollut Bull ; 168: 112402, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34000708

RESUMO

Red algae are increasingly exploited for direct consumption and for production of gelling agents like agar and carrageenan, widely employed in food and personal care products. In this article we identify knowledge gaps about microplastics in the whole commercial life cycle of gelling red algae, from their marine production to the final wastewater treatment. Recommendations for new research include studies of microplastics deposition on red algae at sea, during the industrial process of production of gelling agents, and indeed about improvements of microplastics retention in wastewater treatment plants.


Assuntos
Microplásticos , Rodófitas , Animais , Estágios do Ciclo de Vida , Oceanos e Mares , Plásticos
3.
Int J Cancer ; 146(2): 521-530, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31403184

RESUMO

It is critical to identify biomarkers and functional networks associated with aggressive thyroid cancer to anticipate disease progression and facilitate personalized patient management. We performed miRNome sequencing of 46 thyroid tumors enriched with advanced disease patients with a median follow-up of 96 months. MiRNome profiles correlated with tumor-specific histopathological and molecular features, such as stromal cell infiltration and tumor driver mutation. Differential expression analysis revealed a consistent hsa-miR-139-5p downexpression in primary carcinomas from patients with recurrent/metastatic disease compared to disease-free patients, sustained in paired local metastases and validated in publicly available thyroid cancer series. Exogenous expression of hsa-miR-139-5p significantly reduced migration and proliferation of anaplastic thyroid cancer cells. Proteomic analysis indicated RICTOR, SMAD2/3 and HNRNPF as putative hsa-miR-139-5p targets in our cell system. Abundance of HNRNPF mRNA, encoding an alternative splicing factor involved in cryptic exon inclusion/exclusion, inversely correlated with hsa-miR-139-5p expression in human tumors. RNA sequencing analysis revealed 174 splicing events differentially regulated upon HNRNPF repression in our cell system, affecting genes involved in RTK/RAS/MAPK and PI3K/AKT/MTOR signaling cascades among others. These results point at the hsa-miR-139-5p/HNRNPF axis as a novel regulatory mechanism associated with the modulation of major thyroid cancer signaling pathways and tumor virulence.


Assuntos
Biomarcadores Tumorais/metabolismo , Regulação Neoplásica da Expressão Gênica , Ribonucleoproteínas Nucleares Heterogêneas Grupo F-H/genética , MicroRNAs/metabolismo , Neoplasias da Glândula Tireoide/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Processamento Alternativo/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Intervalo Livre de Doença , Feminino , Seguimentos , Perfilação da Expressão Gênica , Ribonucleoproteínas Nucleares Heterogêneas Grupo F-H/metabolismo , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Transdução de Sinais/genética , Taxa de Sobrevida , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/mortalidade , Neoplasias da Glândula Tireoide/patologia
4.
J Phys Chem B ; 113(33): 11479-89, 2009 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-19634875

RESUMO

The molecular self-assembly of macrocycle 4 is induced by the simultaneous coordination of two molecules of 4-pyridyldiphenylphosphine 3, a highly selective ditopic ligand, to Zn-bisporphyrin 1 and a square-planar Pd(II) complex 2.COD. We report a detailed thermodynamic characterization of the assembly process based on the quantification of each one of the two metal(Zn,Pd)-ligand(N,P) pairwise binding interactions implicated in the supramolecular macrocycle and its effective molarity value (EM). The experimental values of the pairwise metal-ligand interactions have been derived from UV-vis, NMR titrations, and isothermal titration calorimetry experiments of reference model systems. In turn, an EM = 1 x 10(-2) M has been determined by relating the experimental overall stability constant determined for the cyclic assembly with the equation to evaluate the statistical (noncooperative) self-assembly equilibrium constant. We used numerical methods (SPECFIT program) to predict the solution behavior (speciation) of two mixtures of the three molecules 1, 3, and 2.COD in a 1:2:1 relative stoichiometry at two different overall concentrations. The method uses the overall stability constant values and the stoichiometries of eleven species (complexes) implicated in the multicomponent equilibrium self-assembly of 4. Estimated stability constants of some of the species were statistically determined. The agreement observed between the theoretical simulations and the experimental data validates the suitability of the theoretical treatment of self-assembly macrocyclization in a three component strategy.

6.
Rev Esp Geriatr Gerontol ; 44(4): 205-8, 2009.
Artigo em Espanhol | MEDLINE | ID: mdl-19573953

RESUMO

OBJECTIVES: To review published data from Spanish hospitals in which comparisons had been made between the mean length of stay in patients admitted to acute geriatric units (AGU) and those admitted to other departments using the diagnosis-related groups (DRG) classification system and to describe our own experience. MATERIAL AND METHODS: The Spanish reports collected in a previous systematic review were reviewed. The case mix of our hospital was added by analyzing episodes in patients older than 74 years old discharged during a 24-month period and included in the most frequent DRGs. The length of stay in patients admitted to the AGU was compared with that in the remaining medical departments in the hospital and with the standard average stay in the corresponding autonomous region. RESULTS: Data were obtained from five Spanish general hospitals. The comparison revealed that the mean length of stay in the AGU was 8-19% shorter than that of similar patients in the other medical departments of the same hospitals. In one hospital, the reduction in the mean length of stay was 21% in patients older than 80 years. In three of the four hospitals where comparisons with the standard were performed, the mean length of stay in the AGU was lower for most of the DRGs, showing reductions of 7-9%. CONCLUSIONS: These results allow us to conclude that, based on the commonly used patient classification and coding system, Spanish AGUs are more efficient than the remaining medical services in the acute hospitalization of elderly patients in our setting.


Assuntos
Geriatria , Unidades Hospitalares/normas , Idoso de 80 Anos ou mais , Humanos , Espanha
7.
J Org Chem ; 73(2): 374-82, 2008 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-18081344

RESUMO

The interaction of a synthetic enantiopure azamacrocyclic receptor (L) with biologically important chiral dicarboxylates (A, 1-7) has been studied by means of potentiometric titrations in 0.15 M NaCl aqueous solution in a wide pH range. This macrocycle forms strong complexes of the type [HnLA](n-2) (with n = 0-5). As a general trend, the binding is much tighter at basic or neutral pH than in acidic medium. Interestingly, nonprotected excitatory amino acids (Asp and Glu) are strongly bound even at acidic pH. Regarding selectivity, the receptor showed stereoselective binding toward those substrates bearing an H-bonding donor at Calpha, being S-selective in most of the cases, except for glutamic acid. Thus, L displayed an excellent enantioselectivity for (S)-malate dianion (KS/KR = 11.50 at pH 10.0 and KS/KR = 6.86 at pH 7.0) and exhibited moderate enantiopreference for (S,S)-tartrate (KSS/KRR = 3.01 at pH 10 and KSS/KRR = 1.70 at pH 7.0). For this last anion, a very good diastereopreference was also observed (KSS/KRS = 8.46 at pH 10 and KSS/KRS = 4.99 at pH 7.0). On the contrary, L is smoothly R-selective toward (R)-Glu (KR/KS = 3.22 at pH 10 and KR/KS = 2.05 at pH 7.0) due to its longer and more flexible molecular structure. The stereoselectivity of the corresponding complexes decreased when decreasing pH values. For the hydroxy derivatives, mass spectrometry also reflected the trends observed by potentiometry and confirmed the receptor:dicarboxylate 1:1 stoichiometry of the supramolecular complexes. Additional experimental techniques were used to study the most stereoselective example. Solution studies by NMR suggested a good geometrical complementarity between the malate dianion and the receptor, which showed a predominant helical conformation in solution. Besides, self-diffusion rates (PGSE) of the diastereomeric complexes with malate also agree with binding data. Circular dichroism was also used in this case at different pH values, showing a very good correlation between the helical content of the receptor and the stereoselectivity of the molecular recognition process.


Assuntos
Compostos Aza/química , Ácidos Carboxílicos/química , Compostos Macrocíclicos/química , Piridinas/química , Sítios de Ligação , Concentração de Íons de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Concentração Osmolar , Prótons , Cloreto de Sódio/química , Soluções/química , Estereoisomerismo , Água/química
8.
Chem Commun (Camb) ; (21): 2224-6, 2006 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-16718310

RESUMO

Cadmium promoted diastereoselective amplification of a single member from a dynamic combinatorial library of stereoisomeric oligoimines of different sizes allows the efficient preparation of a new macrocyclic polyamine.


Assuntos
Técnicas de Química Combinatória , Iminas/química , Compostos Macrocíclicos/química , Biblioteca de Peptídeos , Cádmio/química , Ciclização , Modelos Químicos , Modelos Moleculares , Estrutura Molecular , Poliaminas/química , Estereoisomerismo
9.
Chem Commun (Camb) ; (11): 1227-9, 2006 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-16518499

RESUMO

The highly enantioselective molecular recognition of the malate dianion by a synthetic receptor in aqueous solution has been studied by potentiometric titrations, mass spectrometry (ESI-MS), diffusion measurements (PGSE NMR) and molecular modeling.


Assuntos
Malatos/análise , Água/química , Ânions , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Malatos/química , Modelos Moleculares , Estrutura Molecular , Potenciometria , Soluções , Espectrometria de Massas por Ionização por Electrospray , Estereoisomerismo , Especificidade por Substrato
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA