RESUMO
Lysine crotonylation (Kcr) is a newly discovered post-translational modification, which is structurally and functionally different from the widely studied lysine acetylation. Kcr is found on histones and non-histone proteins, participating in many biological processes through the regulation of chromatin remodeling, metabolism, cell cycle and cellular organization. Among plants, Kcr in histones is not found in the same lysine residues but increases gene expression when it is co-localized with lysine acetylation. Kcr in non-histone proteins is mainly found in the chloroplast, which provides new insight into photosynthesis. In this review, we discuss recent findings on plant Kcr in histone and non-histone proteins, highlighting its biological implications. These findings not only point to new functions for Kcr, but also reveal the mechanisms by which crotonylation regulates cellular processes in plants and may even change the general direction of epigenome and plant regulation.
Assuntos
Epigênese Genética , Lisina , Acetilação , Histonas/metabolismo , Lisina/metabolismo , Processamento de Proteína Pós-TraducionalRESUMO
Pharmaceutical active compounds (PhACs) are environmentally ubiquitous around the world, and the countries of Latin America (LATAM) are not the exception; however there is still little knowledge of the magnitude and conditions of their occurrence in LATAM and of the environmental consequences of their presence. The present work reviews 79 documents published from 2007 to 2019 on the occurrence, concentrations, and sources of PhACs and hormones in surface water (SW), wastewater (WW), and treated wastewater (TWW) in LATAM and on the circumstances of their release to the environment. Research efforts are reported in only ten countries and confirm the presence of 159 PhACs, mainly analgesics and anti-inflammatories, although extraordinarily high concentrations of carbamazepine (830 µg/L) and ethinylestradiol (6.8 µg/L) were found in Ecuador and Brazil, respectively. The analysis of maximum concentrations and the ecotoxicological risk assessment corroborate that (1) these values exceed the environmental concentrations found in other parts of the world, (2) the environmental risk posed by these concentrations is remarkably high, and (3) there is no statistically significant difference between the maximum concentrations found in WW and those found in TWW. The main source of PhACs in LATAM's aquatic environment is WW; hence, these countries should direct substantial efforts to develop efficient and cost-effective treatment technologies and plan and apply WW management strategies and regulations. This analysis presents the current states of occurrence, concentrations, and sources of PhACs in the aquatic environment of LATAM and outlines the magnitude of the environmental problem in that part of the world.
Assuntos
Preparações Farmacêuticas , Poluentes Químicos da Água , Brasil , Equador , Monitoramento Ambiental , América Latina , Águas Residuárias , Poluentes Químicos da Água/análiseRESUMO
La diferenciación rápida del tipo de estafilococo hallado en los hemocultivos permite establecer tempranamente un tratamiento apropiado y evita el inicio de antibióticos de tipo glicopéptido. Objetivo: determinar el rendimiento de la prueba de la coagulasa, hecha directamente con el contenido de los viales de hemocultivos, en los cuales se detectaba crecimiento de cocos grampositivos compatibles con estafilococos. Métodos: en caso de observar en el vial de hemocultivo solo cocos grampositivos compatibles con estafilococos, se procedía a hacer la prueba directa de la coagulasa, interpretándola cuatro horas después. Se hacían subcultivo e identificación de la bacteria y se comparaba el resultado con el de la prueba directa. Resultados: se hicieron 1.518 pruebas de coagulasa directa de las que 411 (27,1%) fueron positivas y 1.107 (72,9%), negativas. Se cultivaron 446 cepas de S. aureus de las que 410 tuvieron la prueba de coagulasa directa positiva, para una sensibilidad del 91,9%. Solo en un vial de los 411 con la prueba positiva se aisló un Staphylococcus spp., coagulasa negativa, lo cual determinó una especificidad del 99,8%. El valor predictivo positivo fue 99,7% y el negativo, 96,7%. Conclusiones: los resultados confirman la utilidad de la prueba de la coagulasa directa en los viales de hemocultivos para diferenciar oportunamente el tipo de estafilococo cultivado. Se puede emplear como una prueba presuntiva para decidir el inicio o no del tratamiento empírico del paciente infectado por cocos grampositivos, al obtener el reporte preliminar de los hemocultivos.
Rapid differentiation of Staphylococcus spp. strains grown in bood cultures is the basis for early and appropriate treatment of S. aureus infections. Objective: To evaluate the usefulness of the direct tube coagulase test done from blood culture vials with presumptive growth of Staphylococci. Methods: Direct tube coagulase test was carried out if only clusters of gram-positive cocci were observed in the blood culture vials; interpretation was done four hours later and results were compared with those obtained with colonies from subcultures. Results: 1.518 direct tube coagulase tests were carried out; of them, 411 (27.1%) were positive and 1.107 (72.9%), negative. Out of the 446 strains of S. aureus that were isolated, 410 had positive direct tube coagulase test (sensitivity 91.9%). An additional strain of S. aureus was positive in the direct test but negative in the subculture (specificity 99.9%). Predictive values were 99.7% (positive) and 96.7% (negative). Conclusions: Our results confirm the usefulness of the direct tube coagulase test done from blood cultures to opportunely differentiate staphylococci grown in blood cultures. Information so obtained may be used to decide the beginning of empirical treatment.
Assuntos
Coagulase , Testes Laboratoriais , Staphylococcus , Staphylococcus aureusRESUMO
In México, uncontrolled landfills or open-dumps are regularly used as "sanitary landfills". Interactions between landfills/open-dumps and shallow unconfined aquifers have been widely documented. Therefore, evidence showing the occurrence of aquifer contamination may encourage Mexican decision makers to enforce environmental regulations. Traditional methods such as chemical analysis of groundwater, hydrological descriptions, and geophysical studies including vertical electrical sounding (VES) and ground penetrating radar (GPR) were used for the identification and delineation of a contaminant plume in a shallow aquifer. The Guadalupe Victoria landfill located in Mexicali is used as a model study site. This landfill has a shallow aquifer of approximately 1m deep and constituted by silty sandy soil that may favor the transport of landfill leachate. Geophysical studies show a landfill leachate contaminant plume that extends for 20 and 40 m from the SE and NW edges of the landfill, respectively. However, the zone of the leachate's influence stretches for approximately 80 m on both sides of the landfill. Geochemical data corroborates the effects of landfill leachate on groundwater.
Assuntos
Monitoramento Ambiental , Poluentes Químicos da Água , Poluição Química da Água/prevenção & controle , Cidades , MéxicoRESUMO
In Medellin, Colombia, three Pseudomonas aeruginosa isolates with high-level carbapenem resistance (MIC>or=256 microg/ml) and an isolate of Citrobacter freundii with reduced susceptibility to imipenem produced the plasmid-mediated class A carbapenemase KPC-2. This is the first report of a KPC-type beta-lactamase identified outside of the family Enterobacteriaceae.
Assuntos
Farmacorresistência Bacteriana/genética , Pseudomonas aeruginosa/enzimologia , beta-Lactamases/metabolismo , Carbapenêmicos/metabolismo , Carbapenêmicos/farmacologia , Hidrólise , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/genética , beta-Lactamases/genéticaRESUMO
The plasmid-mediated class A carbapenemase KPC-2 was isolated from unrelated Klebsiella pneumoniae isolates in Medellin, Colombia. These KPC enzymes are the first from South America and the second isolation outside of the United States. The expanding geographic spread of KPC carbapenemases underscores the importance of clinical recognition of these enzymes.
Assuntos
Proteínas de Bactérias/genética , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Plasmídeos/genética , beta-Lactamases/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/classificação , Proteínas de Bactérias/metabolismo , Sequência de Bases , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana/genética , Humanos , Ponto Isoelétrico , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Dados de Sequência Molecular , Fases de Leitura Aberta , América do Sul/epidemiologia , beta-Lactamases/classificação , beta-Lactamases/metabolismoRESUMO
El presente estudio tuvo como objetivo estudiar la eficacia y seguridad de la claritromicina en pacientes de 10 o más años de edad con diagnóstico de amigdalofaringitis aguda estreptocóccica. De 188 pacientes estudiados, 43 (22.8%) tuvieron la prueba rápida (Test Pack Strep A) y el cultivo positivo para Streptococcus pyogenes; 40 fueron tratados con claritromicina a una dosis de 250 mgs/12 horas/10 días. Todas las cepas de S. pyogenes identificadas resultaron ser sensibles In vitro a este nuevo macrólido. En la evaluación clínica, 5-7 días post-tratamiento, 39 (97%) estaban clínicamente curados y el restante presentó mejoría. La evaluación bacteriológica demostró erradicación de la bacteria en 37 (92.5%) y persistencia o recaída en los 3 restantes. Se presentaron pocos efectos adversos y ninguno de ellos obligó a suspender el tratamiento. La claritromicina resultó ser efectiva y bien tolerada en el tratamiento de la amigdalofaringitis aguda estreptocóccica.