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131.
Aguirre MC Delporte C Backhouse N Erazo S Letelier ME Cassels BK Silva X Alegría S Negrete R 《Bioorganic & medicinal chemistry》2006,14(16):5673-5677
Leaf extracts of Ugni molinae Turcz. are used in the Chilean cosmetic industry on the assumption that they have decongestant, regenerative, and anti-aging properties. A bioassay-guided fractionation of this plant material showed that some extracts have potent anti-inflammatory activities. Further fractionation led to the isolation and identification of betulinic acid, a mixture of ursolic and oleanolic acids, and the 2alpha-hydroxy derivatives alphitolic, asiatic, and corosolic acids. The latter three were evaluated in vivo in the mouse ear assay for their topical anti-inflammatory activity, inducing inflammation with either arachidonic acid (AA) or 12-O-tetradecanoylphorbol-13 acetate (TPA). Only corosolic acid was active in the AA assay, with similar potency to nimesulide, but all three triterpene acids inhibited TPA-induced inflammation with potencies comparable to that of indomethacin. 相似文献
132.
Rocío Navarro-Olmos Laura Kawasaki Lenin Domínguez-Ramírez Laura Ongay-Larios Rosario Pérez-Molina Roberto Coria 《Molecular biology of the cell》2010,21(3):489-498
The Kluyveromyces lactis heterotrimeric G protein is a canonical Gαβγ complex; however, in contrast to Saccharomyces cerevisiae, where the Gγ subunit is essential for mating, disruption of the KlGγ gene yielded cells with almost intact mating capacity. Expression of a nonfarnesylated Gγ, which behaves as a dominant-negative in S. cerevisiae, did not affect mating in wild-type and ΔGγ cells of K. lactis. In contrast to the moderate sterility shown by the single ΔKlGα, the double ΔKlGα ΔKlGγ mutant displayed full sterility. A partial sterile phenotype of the ΔKlGγ mutant was obtained in conditions where the KlGβ subunit interacted defectively with the Gα subunit. The addition of a CCAAX motif to the C-end of KlGβ, partially suppressed the lack of both KlGα and KlGγ subunits. In cells lacking KlGγ, the KlGβ subunit cofractionated with KlGα in the plasma membrane, but in the ΔKlGα ΔKlGγ strain was located in the cytosol. When the KlGβ-KlGα interaction was affected in the ΔKlGγ mutant, most KlGβ fractionated to the cytosol. In contrast to the generic model of G-protein function, the Gβ subunit of K. lactis has the capacity to attach to the membrane and to activate mating effectors in absence of the Gγ subunit. 相似文献
133.
J Cabello J S?mann E Gómez-Orte T Erazo A Coppa A Pujol I Büssing B Schulze J M Lizcano I Ferrer R Baumeister E Dalfo 《Cell death & disease》2014,5(3):e1120
Apoptotic cell death is an integral part of cell turnover in many tissues, and proper corpse clearance is vital to maintaining tissue homeostasis in all multicellular organisms. Even in tissues with high cellular turnover, apoptotic cells are rarely seen because of efficient clearance mechanisms in healthy individuals. In Caenorhabditis elegans, two parallel and partly redundant conserved pathways act in cell corpse engulfment. The pathway for cytoskeletal rearrangement requires the small GTPase CED-10 Rac1 acting for an efficient surround of the dead cell. The CED-10 Rac pathway is also required for the proper migration of the distal tip cells (DTCs) during the development of the C. elegans gonad. Parkin, the mammalian homolog of the C. elegans PDR-1, interacts with Rac1 in aged human brain and it is also implicated with actin dynamics and cytoskeletal rearrangements in Parkinsons''s disease, suggesting that it might act on engulfment. Our genetic and biochemical studies indicate that PDR-1 inhibits apoptotic cell engulfment and DTC migration by ubiquitylating CED-10 for degradation. 相似文献
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135.
Jesse M. Wilson Emelia J. Chamberlain Natalia Erazo Melissa L. Carter Jeff S. Bowman 《Environmental microbiology》2021,23(6):3225-3239
A multitude of concurrent biological and physical processes contribute to microbial community turnover, especially in highly dynamic coastal environments. Characterizing what factors contribute most to shifts in microbial community structure and the specific organisms that correlate with changes in the products of photosynthesis improves our understanding of nearshore microbial ecosystem functions. We conducted high frequency sampling in nearshore Southern California in order to capture sub-weekly microbial community dynamics. Microbial communities were characterized by flow cytometry and 16S rRNA gene sequencing, and placed in the context of physicochemical parameters. Within our time-series, season and nutrient availability corresponded to changes in dominant microbial community members. Concurrent aseasonal drivers with overlapping scales of variability were also apparent when we used network analysis to assess the microbial community as subsets of the whole. Our analyses revealed the microbial community as a mosaic, with overlapping groups of taxa that varied on different timescales and correlated with unique abiotic and biotic factors. Specifically, a subnetwork associated with chlorophyll a exhibited rapid turnover, indicating that ecologically important subsets of the microbial community can change on timescales different than and in response to factors other than those that govern turnover of most members of the assemblage. 相似文献
136.
Ortiz-Luevano Ricardo López-Bucio José Martínez-Trujillo Miguel Sánchez-Calderón Lenin 《Biometals》2021,34(3):603-620
BioMetals - As sessile organisms, plants respond to changing environments modulating their genetic expression, metabolism and postembryonic developmental program (PDP) to adapt. Among environmental... 相似文献
137.
Sylvie Lenin Jean Michel Alonso Colette Brezin Murielle Rocancourt Olivier Poupel 《FEMS microbiology letters》1986,37(1):89-94
Abstract Adherence of B. pertussis to NIH3T3 mouse fibroblasts was efficiently inhibited by a mouse immune serum reacting specifically with the filamentous haemagglutinin (FHA), whereas a mouse immune serum reacting specifically with the pertussis toxin (Ptx) produced partial inhibition only significant after 3 h infection. Protection against cytopathic effects on infected 3T3 cells with anti-FHA antibodies was at least as effective (83.3%± 7.5) as with anti-Ptx antibodies (75%± 4). This suggests that adherence of B. pertussis to eukaryotic receptors is a primary mechanism determining both bacterial proliferation and toxic effects in susceptible cells, and that prevention of B. pertussis attachment to cell receptors might be sufficient to protect against both infectious and toxic processes in whooping cough. 相似文献
138.
Pau Muoz-Guardiola Josefina Casas Elisabet Megías-Roda Snia Sol Hctor Perez-Montoyo Marc Yeste-Velasco Tatiana Erazo Nora Diguez-Martínez Sergio Espinosa-Gil Cristina Muoz-Pinedo Guillermo Yoldi Jose L Abad Miguel F Segura Teresa Moran Margarita Romeo Joaquim Bosch-Barrera Ana Oaknin Jose Alfn Carles Domnech Gemma Fabris Guillermo Velasco Jose M Lizcano 《Autophagy》2021,17(6):1349
139.
Esteban Ortiz-Prado Katherine Simbaa-Rivera Lenin Gmez Barreno Ana Maria Diaz Alejandra Barreto Carla Moyano Vannesa Arcos Eduardo Vsconez-Gonzlez Clara Paz Fernanda Simbaa-Guaycha Martin Molestina-Luzuriaga Raúl Fernndez-Naranjo Javier Feijoo Aquiles R. Henriquez-Trujillo Lila Adana Andrs Lpez-Corts Isabel Fletcher Rachel Lowe 《PLoS neglected tropical diseases》2021,15(1)
The SARS-CoV-2 virus has spread rapidly around the globe. Nevertheless, there is limited information describing the characteristics and outcomes of COVID-19 patients in Latin America. We conducted a cross-sectional analysis of 9,468 confirmed COVID-19 cases reported in Ecuador. We calculated overall incidence, mortality, case fatality rates, disability adjusted life years, attack and crude mortality rates, as well as relative risk and relative odds of death, adjusted for age, sex and presence of comorbidities. A total of 9,468 positive COVID-19 cases and 474 deaths were included in the analysis. Men accounted for 55.4% (n = 5, 247) of cases and women for 44.6% (n = 4, 221). We found the presence of comorbidities, being male and older than 65 years were important determinants of mortality. Coastal regions were most affected by COVID-19, with higher mortality rates than the highlands. Fatigue was reported in 53.2% of the patients, followed by headache (43%), dry cough (41.7%), ageusia (37.1%) and anosmia (36.1%). We present an analysis of the burden of COVID-19 in Ecuador. Our findings show that men are at higher risk of dying from COVID-19 than women, and risk increases with age and the presence of comorbidities. We also found that blue-collar workers and the unemployed are at greater risk of dying. These early observations offer clinical insights for the medical community to help improve patient care and for public health officials to strengthen Ecuador’s response to the outbreak. 相似文献
140.
Benjamin Klempay Nestor Arandia-Gorostidi Anne E. Dekas Douglas H. Bartlett Christopher E. Carr Peter T. Doran Avishek Dutta Natalia Erazo Luke A. Fisher Jennifer B. Glass Alexandra Pontefract Sanjoy M. Som Jesse M. Wilson Britney E. Schmidt Jeff S. Bowman 《Environmental microbiology》2021,23(7):3825-3839
Concurrent osmotic and chaotropic stress make MgCl2-rich brines extremely inhospitable environments. Understanding the limits of life in these brines is essential to the search for extraterrestrial life on contemporary and relict ocean worlds, like Mars, which could host similar environments. We sequenced environmental 16S rRNA genes and quantified microbial activity across a broad range of salinity and chaotropicity at a Mars-analogue salt harvesting facility in Southern California, where seawater is evaporated in a series of ponds ranging from kosmotropic NaCl brines to highly chaotropic MgCl2 brines. Within NaCl brines, we observed a proliferation of specialized halophilic Euryarchaeota, which corresponded closely with the dominant taxa found in salterns around the world. These communities were characterized by very slow growth rates and high biomass accumulation. As salinity and chaotropicity increased, we found that the MgCl2-rich brines eventually exceeded the limits of microbial activity. We found evidence that exogenous genetic material is preserved in these chaotropic brines, producing an unexpected increase in diversity in the presumably sterile MgCl2-saturated brines. Because of their high potential for biomarker preservation, chaotropic brines could therefore serve as repositories of genetic biomarkers from nearby environments (both on Earth and beyond) making them prime targets for future life-detection missions. 相似文献