11 research outputs found

    Efectos de cadmio en compuestos fenolicos totales y flavonoides de Euglena gracilis

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    In the present study the production of phenolic acids and flavonoid compounds by E. gracilis exposed to two cadmium concentrations (0.02 and 0.14 mM) was evaluated using high-performance liquid chromatography (HPLC). The results showed that E. gracilis exposed to 0.02 mM Cd+2 increased significantly the total content of phenolic compounds (798.46 ± 12.61 ?g GA/g) and total flavonoids (241.34 ± 47.63 ?g QE/g) with respect to the control (137.34 ± 19.80 ?g QE/g DW and 549.00 ± 8.57 ?g GA/g DW, respectively). However, no significant increase in the total content of phenolic compounds (568.54 ± 17.42 ?g GA/g DW) and total flavonoids (141.11 ± 9.36 ?g QE/g DW) were observed in E. gracilis exposed to 0.14 mM Cd+2. Further research is necessary to determine the specific role of flavonoids in E. gracilis exposed to high concentrations of Cd+2.En el presente estudio la producción de compuestos fenolicos y flavonoides producidos por E. gracilis expuesto a dos concentraciones de cadmio fue evaluado usando cromatografía liquida de alta precisión (HPLC). Los resultados mostraron que 0.02 mM de Cd+2 incrementaba significativamente el contenido total de compuestos fenolicos (798.46 ± 12.61 ?g GA/g) y flavonoides (241.34 ± 47.63 ?g QE/g) con respecto al control (137.34 ± 19.80 ?g QE/g DW y 549.00 ± 8.57 ?g GA/g DW) respectivamente. Sin embargo, incrementos no significativos en el contenido de compuestos fenolicos (568.54 ± 17.42 ?g GA/g DW) y flavonoides totales (141.11 ± 9.36 ?g QE/g DW) fueron observados en E. gracilis expuestas a 0.14 mM de Cd+2. Futuros estudios son necesarios para determinar la función especifica de los flavonoides en E. gracilis expuesto a altas concentraciones de Cd+2

    OptimizaciĂłn de los reguladores de crecimiento para maximizar el nĂșmero de brotes en Agave americana L. por organogĂ©nesis indirecta

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    Current protocols for Agave americana L. micropropagation have limited commercial application due to the low number of plants produced by explant. Indirect organogenesis could be an alternative, however is necessary to optimize plant growth regulators for plantlet number maximization. The objective of this work was to optimize 2,4-dicholorophenoxyacetic acid (2,4-D) and 6-benzyl adenine (BA) concentrations on the induction of A. americana embryogenic callus from apical meristem as explant for maximized the number of shoots per callus using a response surface experimental design. MS medium containing 30 g l-1 sucrose amended with 0.11,0.18, 0.45 or 2.26 ?M 2,4-D, and 11.0, 22.0, 38.2 or 44.0 ?M BA was used. Nine treatments with three repetitions was applied and number of shoots per callus were monitored after 4, 16, 20 and 36 weeks. In vitro rooting of shoot was done in MS medium added with indole butyric acid (IBA). A maximum number of plantlets per explant (74) was obtained with 2.26 ?M of 2,4-D and 38.2 ?M BA. In conclusion, the indirect organogenesis of A. americana L. could be an alternative for obtain plantlets for propagation commercial purposes.Los protocolos actuales para la micropropagaciĂłn de Agave americana L. tienen limitaciones para su aplicaciĂłn comercial debido al bajo nĂșmero de plantas producidas por cada explante. La organogĂ©nesis indirecta podrĂ­a ser una alternativa, sin embargo, es necesario optimizar los reguladores de crecimiento vegetal para maximizar el nĂșmero de plantas. El objetivo del trabajo fue optimizar la concentraciĂłn de ĂĄcido 2,4-diclorofenoxiacetico (2,4-D) y de 6-bencil adenina (BA) sobre la inducciĂłn de callos embriogĂ©nicos en A. americana usando meristemos apicales como explante para maximizar el nĂșmero de brotes por callo, utilizando un diseño experimental de superficie de respuesta. Se utilizĂł el medio Murashige Skoog (MS) adicionado con 30 g l-1 de sacarosa, y con 0,11;0,18; 0,45 o 2,26 ?M de 2,4-D, y 11,0; 22,0; 38,2 o 44,0 ?M de BA. Se implementaron 9 tratamientos con 3 repeticiones y el nĂșmero de brotes por callo fue evaluado despuĂ©s de 4, 16, 20 y 36 semanas. Se indujo el enraizamiento in vitro usando medio MS adicionado con ĂĄcido indolbutĂ­rico (AIB). Se obtuvo un mĂĄximo de 74 plĂĄntulas por callo, usando 2,26 ?M de 2,4-D y 38,2 ?M de BA. En conclusiĂłn, la organogĂ©nesis indirecta podrĂ­a ser una alternativa para la micropropagaciĂłn de A. americana L con fines comerciales

    Actividad antifĂșngica de extractos de Crotalaria longirostrata Hook. & Arn. contra hongos fitopatĂłgenos de maĂ­z

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    In the present study, the hexane, acetone and methanol extracts of stem, branches and roots from Crotalaria longirostrata were evaluated for their antifungal activity against Fusarium sp., Fusarium verticillioides and Aspergillus flavus. The variables analyzed were inhibition halos, mycelial growth inhibition, sporulation and minimum inhibitory concentration. Phytochemical analysis revealed the presence of saponins, coumarins, anthrones, anthraquinones, flavonoids and alkaloids on different organic extracts. The hexane extract showed zones of inhibition between 6.3 and 10.5 mm. The mycelia growth and sporulation of A. flavus were reduced to 90% with methanol extract. The minimum inhibitory concentration values obtained with hexane extracts were 6.75 mg mL-1 and with methanol extracts were 50 and 25 mg mL-1 for Fusarium strains. This is the first study reporting of phytochemical composition and biological activity of C. longirostrata that could be used as a natural alternative to control in vitro of certain important pathogenic fungi.En el presente estudio se evaluĂł la actividad antifĂșngica de los extractos hexĂĄnicos, cetĂłnicos y metanĂłlicos de tallo, ramas y raĂ­ces de Crotalaria longirostrata frente a los hongos Fusarium sp., Fusarium verticillioides y Aspergillus flavus. Las variables analizadas fueron halos de inhibiciĂłn, la inhibiciĂłn del crecimiento micelial, la inhibiciĂłn de la esporulaciĂłn y la concentraciĂłn mĂ­nima inhibitoria. El anĂĄlisis fitoquĂ­mico revelĂł la presencia de saponinas, cumarinas, antronas, antraquinonas, flavonoides y alcaloides en los diferentes extractos orgĂĄnicos. Los extractos hexĂĄnicos mostraron zonas de inhibiciĂłn entre 6,3 y 10,5 mm. El crecimiento micelial y la esporulaciĂłn de A. flavus se redujo 90% con los extractos metanĂłlicos. El valor de la concentraciĂłn mĂ­nima inhibitoria obtenida con los extractos hexĂĄnicos fue 6,75 mg mL-1 y con los extractos metanĂłlicos fueron 50 y 25 mg ml-1 para las cepas de Fusarium. Este es el primer reporte del estudio de la composiciĂłn fitoquĂ­mica y la actividad biolĂłgica de C. longirostrata que podrĂ­a ser utilizada como una alternativa natural para el control in vitro de ciertos hongos patĂłgenos importantes

    Global overview of the management of acute cholecystitis during the COVID-19 pandemic (CHOLECOVID study)

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    Background: This study provides a global overview of the management of patients with acute cholecystitis during the initial phase of the COVID-19 pandemic. Methods: CHOLECOVID is an international, multicentre, observational comparative study of patients admitted to hospital with acute cholecystitis during the COVID-19 pandemic. Data on management were collected for a 2-month study interval coincident with the WHO declaration of the SARS-CoV-2 pandemic and compared with an equivalent pre-pandemic time interval. Mediation analysis examined the influence of SARS-COV-2 infection on 30-day mortality. Results: This study collected data on 9783 patients with acute cholecystitis admitted to 247 hospitals across the world. The pandemic was associated with reduced availability of surgical workforce and operating facilities globally, a significant shift to worse severity of disease, and increased use of conservative management. There was a reduction (both absolute and proportionate) in the number of patients undergoing cholecystectomy from 3095 patients (56.2 per cent) pre-pandemic to 1998 patients (46.2 per cent) during the pandemic but there was no difference in 30-day all-cause mortality after cholecystectomy comparing the pre-pandemic interval with the pandemic (13 patients (0.4 per cent) pre-pandemic to 13 patients (0.6 per cent) pandemic; P = 0.355). In mediation analysis, an admission with acute cholecystitis during the pandemic was associated with a non-significant increased risk of death (OR 1.29, 95 per cent c.i. 0.93 to 1.79, P = 0.121). Conclusion: CHOLECOVID provides a unique overview of the treatment of patients with cholecystitis across the globe during the first months of the SARS-CoV-2 pandemic. The study highlights the need for system resilience in retention of elective surgical activity. Cholecystectomy was associated with a low risk of mortality and deferral of treatment results in an increase in avoidable morbidity that represents the non-COVID cost of this pandemic

    MAGIC and H.E.S.S. detect VHE gamma rays from the blazar OT081 for the first time: a deep multiwavelength study

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    https://pos.sissa.it/395/815/pdfPublished versio

    Changes in the phenylalanine ammonia lyase activity, total phenolic compounds, and flavonoids in Prosopis glandulosa treated with cadmium and copper

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    ABSTRACT The aim of the present work is to evaluate the changes on the phenylalanine ammonia lyase (PAL) activity, phenolic compounds accumulation and photochemical efficiency in leaves of P. glandulosa treated with Cd2+ (0.001 M) and Cu2+ (0.52 M) concentrations for 96 h under hydroponic conditions. The results showed that only leaves treated with copper had a decrease in photochemical efficiency and leaf epidermal polyphenols in P. glandulosa leaves after 96 h of exposure. On the other hand the reverse-phase HPLC analysis revealed higher levels of phenolic compound (gallic, vanillic and caffeic acids) and flavonoids (rutin and kaempferol-3-O-glucosides) in plant leaves from Cu and Cd-treatments with respect to control plants. Finally, highest increments in PAL activity was observed in extracts of leaves treated with Cu and Cd (about 205 and 284%), respectively, with respect to control plants after 96 h treatment. These suggest that activation of phenylpropanoid pathway represent a source of nonenzymatic antioxidants that protect at P. glandulosa against oxidative stress when exposed to cadmium and copper. Hence future studies are necessary to elucidate the participation of phenylpropanoid pathway in the reduction of metal toxicity in Prosopis species

    Changes of photochemical efficiency and epidermal polyphenols content of Prosopis glandulosa and Prosopis juliflora leaves exposed to cadmium and copper

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    The effect of metals on the photosynthetic activities and epidermal polyphenol content of Prosopis glandulosa and Prosopis juliflora leaves was investigated by the tissue tolerance test. Foliar tissues of Prosopis glandulosa and Prosopis juliflora were incubated with Cd2+ (0.001 M) or Cu2+ (0.52 M) concentrations for 96 h. The results showed that significant reductions (p < 0.05) of photochemical efficiency in P. juliflora leaves were found after 96 h of exposure to 0.52 M Cu2+ compared with Cd-treatments and controls. In contrast, P. glandulosa leaves showed a progressive increase on photochemical efficiency at 72 h after Cu-treatment. The results also showed a significant decrease (p < 0.05) of epidermal polyphenols in P. juliflora leaves after 24 h of exposure to 0.52 M Cu2+ compared with Cd-treatments and control leaves. On the other hand, the values of leaf epidermal polyphenols observed in P. glandulosa exposed to copper and cadmium did not show any difference with respect to control. These findings are very important and suggest that these compounds could be considered as a protection mechanism of P. glandulosa when is treated with these heavy metals. Finally, the results of bioaccumulation showed that the copper concentration in P. glandulosa was higher than the values detected in P. juliflora Nevertheless, the cadmium concentration in foliar tissues of P. juliflora was significantly higher than P. glandulosa after 96 h of exposure to Cu2+ or Cd2+. Therefore, future studies are necessary to elucidate the effects of heavy metals on the biosynthesis of flavonoids and participation of these compounds in the reduction of metal toxicity in Prosopis species

    Transcatheter Aortic Valve Replacement in Pure Native Aortic Valve Regurgitation

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    Background Limited data exist about safety and efficacy of transcatheter aortic valve replacement (TAVR) in patients with pure native aortic regurgitation (AR). Objectives This study sought to compare the outcomes of TAVR with early- and new-generation devices in symptomatic patients with pure native AR. Methods From the pure native AR TAVR multicenter registry, procedural and clinical outcomes were assessed according to VARC-2 criteria and compared between early- and new-generation devices. Results A total of 331 patients with a mean STS score of 6.7 ± 6.7 underwent TAVR. The early- and new-generation devices were used in 119 patients (36.0%) and 212 patients (64.0%), respectively. STS score tended to be lower in the new-generation device group (6.2 ± 6.7 vs. 7.6 ± 6.7; p = 0.08), but transfemoral access was more frequently used in the early-generation device group (87.4% vs. 60.8%; p < 0.001). Compared with the early-generation devices, the new-generation devices were associated with a significantly higher device success rate (81.1% vs. 61.3%; p < 0.001) due to lower rates of second valve implantation (12.7% vs. 24.4%; p = 0.007) and post-procedural AR Ăą\u89„ moderate (4.2% vs. 18.8%; p < 0.001). There were no significant differences in major 30-day endpoints between the 2 groups. The cumulative rates of all-cause and cardiovascular death at 1-year follow-up were 24.1% and 15.6%, respectively. The 1-year all-cause mortality rate was significantly higher in the patients with post-procedural AR Ăą\u89„ moderate compared with those with post-procedural AR Ăą\u89€ mild (46.1% vs. 21.8%; log-rank p = 0.001). On multivariable analysis, post-procedural AR Ăą\u89„ moderate was independently associated with 1-year all-cause mortality (hazard ratio: 2.85; 95% confidence interval: 1.52 to 5.35; p = 0.001). Conclusions Compared with the early-generation devices, TAVR using the new-generation devices was associated with improved procedural outcomes in treating patients with pure native AR. In patients with pure native AR, significant post-procedural AR was independently associated with increased mortality

    Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

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    Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P &lt; 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)
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