Correlation Between Tacrolimus Levels in Blood Samples Obtained from Central Catheter and Peripheral Venipuncture in Lung Transplant Patients (Ven-Cat Study).

BACKGROUND: Following lung transplantation (LT), receiving immunosuppressive therapy is crucial. Tacrolimus is considered a drug with a narrow therapeutic range and its use requires constant monitoring. This study aimed to evaluate the correlation between tacrolimus levels obtained from central venous catheter and direct venipuncture in adult patients undergoing LT. METHODS: This prospective study included LT patients hospitalized in conventional ward carrying a central catheter through which no intravenous tacrolimus was administered. Trough samples were obtained through direct puncture and from the central catheter. Pearson correlation coefficient was calculated to quantify the mean difference between the 2 measures. RESULTS: A total of 54 sample pairs from 16 LT patients were obtained, mostly male (81.3%) and bilateral transplant recipients (93.8%); the transplant procedure was the primary reason for admission (81.3%). The difference in tacrolimus levels between both samples was 0.3 (0.1-0.6) mcg/L, with the measurement for the samples obtained through venipuncture being mostly higher than that for those obtained from the catheter. A strong correlation was observed between the tacrolimus levels in the samples obtained from the catheter and through venipuncture (Pearson correlation coefficient, 0.991; P < 0.001; R2 = 0.982). CONCLUSIONS: There is an excellent correlation between tacrolimus levels obtained from venipuncture and those obtained from central venous catheter in LT patients undergoing oral tacrolimus therapy.

Maf1 phosphorylation is regulated through the action of prefoldin-like Bud27 on PP4 phosphatase in Saccharomyces cerevisiae.

Bud27 is a prefoldin-like protein that participates in transcriptional regulation mediated by the three RNA polymerases in Saccharomyces cerevisiae. Lack of Bud27 significantly affects RNA pol III transcription, although the involved mechanisms have not been characterized. Here, we show that Bud27 regulates the phosphorylation state of the RNA pol III transcriptional repressor, Maf1, influences its nuclear localization, and likely its activity. We demonstrate that Bud27 is associated with the Maf1 main phosphatase PP4 in vivo, and that this interaction is required for proper Maf1 dephosphorylation. Lack of Bud27 decreases the interaction among PP4 and Maf1, Maf1 dephosphorylation, and its nuclear entry. Our data uncover a new nuclear function of Bud27, identify PP4 as a novel Bud27 interactor and demonstrate the effect of this prefoldin-like protein on the posttranslational regulation of Maf1. Finally, our data reveal a broader effect of Bud27 on PP4 activity by influencing, at least, the phosphorylation of Rad53.

Immunization with a Mu-class glutathione transferase from Echinococcus granulosus induces efficient antibody responses and confers long-term protection against secondary cystic echinococcosis.

Cystic echinococcosis, a zoonosis caused by cestodes belonging to the Echinococcus granulosus sensu lato (s.l.) genetic complex, affects humans and diverse livestock species. Although a veterinary vaccine exhibiting high levels of antibody-mediated protection has successfully reached the market, the large genetic diversity among parasite isolates and their particular host preferences, makes still necessary the search for novel vaccine candidates. Glutathione transferases (GSTs) constitute attractive targets for immunoprophylaxis due to their outstanding relevance in helminth detoxification processes, against both exogenous and endogenous stressors. Among the six GSTs known to be expressed in E. granulosus s.l., EgGST1 (Mu-class), EgGST2 (Sigma-class), and EgGST3 (a still non-classifiable isoenzyme), show the highest proteomic expression. Therefore, their recombinant forms -rEgGST1, rEgGST2 and rEgGST3- were herein analyzed regarding their potential to induce long-term antiparasite protection in mice. Only immunization with rEgGST1 induced long-lasting protection; and accordingly, rEgGST1-specific antibodies enhanced the parasite killing through both the classical activation of the host complement system and the antibody-dependent cellular cytotoxicity by macrophages. These results support further testing of rEgGST1 as a vaccine candidate in diverse hosts due to the broad expression of EgGST1 in different parasite stages and tissues.

Low-complexity continuous-variable quantum key distribution with true local oscillator using pilot-assisted frequency locking.

In the domain of continuous variable quantum key distribution (CV-QKD), a significant challenge arises in achieving precise frequency synchronization, an issue commonly termed as frequency locking. This involves matching the optical frequencies of both the quantum signal laser and the local oscillator laser for accurate symbol demodulation during the exchange of quantum keys. As such, implementations today still grapple with maintaining precise synchronization between sender and receiver frequencies, occasionally hindering the efficiency and reliability of the information exchange. Addressing this challenge, we present and empirically validate a novel approach to CV-QKD by incorporating a pilot tone-assisted frequency locking algorithm to enhance stability when using a locally generated local oscillator (LLO) at the receiver. The proposed design leverages software-based optimization techniques, thereby eliminating the need for high-speed electronic stabilization devices and achieving efficient performance at typical repetition rates. Specifically, the introduction of the pilot tone algorithm allows us to effectively mitigate phase fluctuations and preserve the integrity of the quantum signals during transmission without resorting to time-multiplexed reference pulses or fast-locking electronics in the lasers. Our results suggest the potential for achieving secure key rates of up to 1 Mb/s over a 50 km single-mode fiber when using these techniques, offering promising insights into the feasibility of high-rate, low-complexity CV-QKD implementations under realistic conditions.

Real-world adalimumab survival and discontinuation factors in hidradenitis suppurativa.

BACKGROUND AND OBJECTIVES: Survival analyses can provide valuable insights into effectiveness and safety as perceived by prescribers. Here, we aimed to evaluate adalimumab (ADA) survival and the interruption risk factors in a multicentre cohort of patients with hidradenitis suppurativa (HS). Moreover, we performed a subanalysis considering the periods before and after the onset of the COVID-19 pandemic. METHODS: We conducted a retrospective study including 539 adult patients with HS who received ADA from 1 May 2015 to 31 December 2022. Overall drug survival was analysed using Kaplan-Meier survival curves and compared between the subgroups via stratified log-rank test. Possible predictors for overall drug survival and reasons for discontinuation were assessed using univariate and multivariate Cox regression. RESULTS: Overall, 50.1% were females with a mean age of 43.5 ± 1 years and a mean BMI of 29.5 ± 6.7. At the start of ADA, 95.29% were biologic-naïve and 24.63% had undergone surgical treatment. During follow-up, 9.46% of patients required dose escalation, while 39.92% interrupted ADA. Concomitant therapy was used in 64.89% of cases. A subanalyses comparing pre- and post-pandemic periods revealed a tendency to initiate ADA treatment at a younger age, among patient with higher BMI and at a lower HS stage after COVID-19 pandemic. Interestingly, ADA demonstrated extended survival compared to previous studies, with a median overall drug survival of 56.2 months (95% CI 51.2 to 80.3). The primary causes for discontinuation were inefficacy (51.69%), followed by adverse effects (21.35%). Female sex, longer delay in HS diagnosis, higher baseline IHS4 score and concomitant spondyloarthritis were associated with poorer ADA survival or increased risk of discontinuation. CONCLUSIONS: ADA demonstrated prolonged survival (median 56.2 months). While addition of antibiotics did not have a positive effect on survival rate, basal IHS4 proved useful in predicting ADA survival.

Impact of Hydroxytyrosol-Rich Extract Supplementation in a High-Fat Diet on Gilthead Sea Bream (Sparus aurata) Lipid Metabolism.

High-fat diets (HFDs) enhance fish growth by optimizing nutrient utilization (i.e., protein-sparing effect); however, their potential negative effects have also encouraged the search for feed additives. This work has investigated the effects of an extract rich in a polyphenolic antioxidant, hydroxytyrosol (HT), supplemented (0.52 g HT/kg feed) in a HFD (24% lipid) in gilthead sea bream (Sparus aurata). Fish received the diet at two ration levels, standard (3% of total fish weight) or restricted (40% reduction) for 8 weeks. Animals fed the supplemented diet at a standard ration had the lowest levels of plasma free fatty acids (4.28 ± 0.23 mg/dL versus 6.42 ± 0.47 in the non-supplemented group) and downregulated hepatic mRNA levels of lipid metabolism markers (ppara, pparb, lpl, fatp1, fabp1, acox1, lipe and lipa), supporting potential fat-lowering properties of this compound in the liver. Moreover, the same animals showed increased muscle lipid content and peroxidation (1.58- and 1.22-fold, respectively, compared to the fish without HT), suggesting the modulation of body adiposity distribution and an enhanced lipid oxidation rate in that tissue. Our findings emphasize the importance of considering this phytocompound as an optimal additive in HFDs for gilthead sea bream to improve overall fish health and condition.

Tendência das taxas de internação por complicações de Diabetes Mellitus na população do município de Macaé, Rio de Janeiro, no período de 2011 a 2021

Objetivo: Avaliar a tendência das taxas de internação por complicações de Diabetes Mellitus na população de Macaé-Rio de Janeiro, 2011-2021. Métodos: Estudo ecológico de séries temporais das taxas de internação por complicações de Diabetes Mellitus na população de Macaé em 2011-2021. Os dados foram obtidos através do Sistema de Informações Hospitalares da plataforma do Datasus. Os modelos de regressão Joinpoint foram utilizados para estimar a tendência da taxa de internação. Resultados: A taxa de internação por complicações de Diabetes Mellitus por ano, de modo geral, foi maior no ano de 2016 e menor taxa no ano de 2020. Entre 2017 e 2021, verificou-seuma tendência significativa decrescente de -19,71% (Intervalo de Confiança -36,71; -9,73) das taxas de internação por complicações de Diabetes Mellitus. Conclusão: Houve uma redução acentuada nas taxas durante a pandemia, o que pode ser devido à subnotificação no registro de internações

Ceftazidime-Avibactam Improves Outcomes in High-Risk Neutropenic Patients with Klebsiella pneumoniae Carbapenemase-Producing Enterobacterales Bacteremia.

Few studies have evaluated the efficacy of ceftazidime-avibactam (CA) for Klebsiella pneumoniae carbapenemase-producing Enterobacterales bacteremia (KPC-PEB) in high-risk neutropenic patients. This is a prospective multicenter observational study in high-risk neutropenic patients with multi-drug resistant Enterobacterales bacteremia. They were compared according to the resistance mechanism and definitive treatment provided: KPC-CPE treated with CA (G1), KPC-CPE treated with other antibiotics (G2), and patients with ESBL-producing Enterobacterales bacteremia who received appropriate definitive therapy (G3). Thirty-day mortality was evaluated using a logistic regression model, and survival was analyzed with Kaplan-Meier curves. A total of 238 patients were included: 18 (G1), 52 (G2), and 168 (G3). Klebsiella spp. (60.9%) and Escherichia coli (26.4%) were the Enterobacterales most frequently isolated, and 71% of the bacteremias had a clinical source. The resistance profile between G1 and G2 was colistin 35.3% vs. 36.5%, amikacin 16.7% vs. 40.4%, and tigeclycline 11.1% vs. 19.2%. The antibiotics prescribed in combination with G2 were carbapenems, colistin, amikacin, fosfomycin, tigecycline, and fluoroquinolones. Seven-day clinical response in G1 vs. G2 vs. G3 was 94.4% vs. 42.3% vs. 82.7%, respectively (p < 0.001). Thirty-day overall mortality in G1 vs. G2 vs. G3 was 22.2% vs. 53.8% vs. 11.9%, respectively (p < 0.001), and infection-related mortality was 5.5% vs. 51.9% vs. 7.7% (p < 0.001). The independent risk factors for mortality were Pitt score > 4: OR 3.63, 95% CI, 1.18-11.14 (p = 0.025) and KPC-PEB treated with other antibiotics: OR 8.85, 95% CI, 2.58-30.33 (p = 0.001), while 7-day clinical response was a protective factor for survival: OR 0.02, 95% CI, 0.01-0.08 (p < 0.001). High-risk neutropenic patients with KPC-CPE treated with CA had an outcome similar to those treated for ESBL-producing Enterobacterales, with higher 7-day clinical response and lower overall and infection-related mortality than those treated with other antibiotics. In view of these data, CA may be considered the preferred therapeutic option for KPC-PEB in high-risk neutropenic patients.

The association of the RSC remodeler complex with chromatin is influenced by the prefoldin-like Bud27 and determines nucleosome positioning and polyadenylation sites usage in Saccharomyces cerevisiae.

The tripartite interaction between the chromatin remodeler complex RSC, RNA polymerase subunit Rpb5 and prefoldin-like Bud27 is necessary for proper RNA pol II elongation. Indeed lack of Bud27 alters this association and affects transcription elongation. This work investigates the consequences of lack of Bud27 on the chromatin association of RSC and RNA pol II, and on nucleosome positioning. Our results demonstrate that RSC binds chromatin in gene bodies and lack of Bud27 alters this association, mainly around polyA sites. This alteration impacts chromatin organization and leads to the accumulation of RNA pol II molecules around polyA sites, likely due to pausing or arrest. Our data suggest that RSC is necessary to maintain chromatin organization around those sites, and any alteration of this organization results in the widespread use of alternative polyA sites. Finally, we also find a similar molecular phenotype that occurs upon TOR inhibition with rapamycin, which suggests that alternative polyadenylation observed upon TOR inhibition is likely Bud27-dependent.

ABA Supplementation Rescues IRS2 and BDNF mRNA Levels in a Triple-Transgenic Mice Model of Alzheimer's Disease.

Insulin resistance underlies Alzheimer's disease (AD) by affecting neuroinflammation and brain-derived neurotrophic factor (BDNF) expression. Here, we evaluated the effect of early and late-start abscisic acid (ABA) intervention on hippocampal BDNF, tumor necrosis factor α (TNFα), and insulin receptors substrates (IRS) 1/2 mRNA levels in a triple-transgenic mice model of AD. Transgenic mice displayed lower BDNF and IRS2, equal IRS1, and higher TNFα expression compared to wild-type mice. Late ABA treatment could rescue TNFα and increased IRS1/2 expression. However, early ABA administration was required to increase BDNF expression. Our data suggests that early intervention with ABA can prevent AD, via rescuing IRS1/2 and BDNF expression.

Optical and Clinical Outcomes of an Isofocal Intraocular Lens vs. a Monofocal Standard Lens.

The aim of this study is to evaluate the results obtained on the optical bench and clinically with an isofocal lens (ISOPure, BVI medical, Belgium) to compare them to a standard monofocal one (MicroPure, BVI medical, Belgium). To do so, we have combined laboratory investigation and a prospective, comparative, and randomized clinical study. First, we have measured the wavefront of the two models studied using a NIMO TR1504 (Lambda-X, Belgium) deflectometer for three nominal powers: +10.00, +20.00 and +30.00 D. In the randomized study with 48 patients, half of them implanted with ISOPure and the other with MicroPure, we have measured visual acuities and contrast sensitivity under photopic and mesopic conditions. The optical bench results show that the isofocal lens presented higher power than the monofocal one, at the lens center, due to the spherical aberration (coefficients Z(4,0), Z(6,0) and Z(8,0)) induced by the greater asphericity of its design. The addition obtained depended on the nominal power, from +1.00 to +1.50 D. The results of the clinical study showed that the ISOPure lens presented better visual outcomes, which were statistically significant, at intermediate distance compared to the MicroPure lens (p-values of 0.014 and 0.022 for 80 and 60 cm, respectively) without decreasing the contrast sensitivity. Clinical outcomes were not affected by pupillary size. In conclusion, due to the increase in power at the lens center due to its highly aspherical design, the isofocal lens evaluated showed better intermediate vision than the monofocal one.

Utilidad del lavado broncoalveolar para la detección microbiológica, y factores asociados, en receptores de trasplante de precursores hematopoyéticos: estudio de cohorte retrospectivo / Usefulness of bronchoalveolar lavage for microbiological detection and asssociated factors in hematopoietic stem cell transplant receivers: a retrospective cohort study

INTRODUCCIÓN: Las opacidades pulmonares en receptores de trasplante de precursores hematopoyéticos (TPH) representan un desafío diagnóstico y son una causa de morbimortalidad. Existen grandes discrepancias con respecto a la sensibilidad diagnóstica del lavado broncoalveolar (LBA), sus complicaciones, y los factores asociados a la identificación microbiológica. OBJETIVO: Conocer la utilidad del estudio microbiológico del LBA en el diagnóstico, modificación de la conducta médica y estimar las complicaciones y mortalidad asociada al procedimiento, en receptores de TPH con opacidades pulmonares. PACIENTES Y MÉTODOS: Estudio de cohorte, retrospectivo, en adultos receptores de TPH a los que se les realizó una broncoscopía con LBA por presentar opacidades pulmonares, en el Hospital Italiano de Buenos Aires entre el 01/01/2011 y el 31/12/2020. RESULTADOS: De los 189 procedimientos analizados, en 79 se logró un hallazgo microbiológico (41,8%) y 122 permitieron modificar la conducta médica (64,6%). En 11 casos se observaron complicaciones graves dentro de las 12 horas (5,8%) de efectuado el LBA. La mortalidad intrahospitalaria fue de 16,8% (N = 21/125). El valor de neutrófilos en sangre previo al LBA (p = 0,037) y la presencia de nódulos pulmonares como lesión tomográfica predominante (p = 0,029) se asociaron independientemente al hallazgo microbiològico global. CONCLUSIONES: Nuestra investigación apoya la realización del LBA como herramienta diagnóstica en pacientes que reciben un TPH y presentan opacidades pulmonares.

BACKGROUND: Lung opacities are a cause of morbimortality in bone marrow transplant patients, and represent a diagnostic challenge. There are large discrepancies regarding the diagnostic sensitivity of bronchoalveolar lavage (BAL), its complications, and the factors associated with microbiological detection. AIM: To know the usefulness of the microbiological study of BAL in the diagnosis, in the modification in medical behavior and to estimate the complications and associated mortality of this diagnostic procedure in patients transplanted with hematopoietic progenitor cells with pulmonary opacities. METHODS: Retrospective cohort study in bone marrow transplant adult patients who underwent bronchoscopy with BAL due to lung opacities at Hospital Italiano de Buenos Aires between 01/01/2011 and 12/31/2020. RESULTS: Of the 189 BAL analyzed, 79 presented a microbiological detection (41.8%) and 122 allowed to modify the medical behavior (64.6%). Severe complications were observed within 12 hours after the procedure in11 cases (5.8%). In-hospital mortality was 16,8% (N = 21/125). The value of blood neutrophils prior to bronchoalveolar lavage (p = 0.037) and the presence of pulmonary nodules as the predominant tomographic lesion (p = 0.029) were independently associated with global microbiological detection. CONCLUSION: Our research supports the performance of BAL as a diagnostic tool in bone marrow transplant patients with lung opacities.

Spaghetti Technique Versus Wide Local Excision for Lentigo Maligna Affecting the Head and Neck Regions: Surgical Outcome and Descriptive Analysis of 79 Cases from a Single Practice Cohort.

INTRODUCTION: Lentigo maligna is a subtype of melanoma in situ that typically affects the head and neck region with an increasing incidence. Margin-controlled techniques, such as spaghetti technique (ST), have gained popularity over wide local excision (WLE) with a margin of 5 mm. OBJECTIVES: To evaluate the outcomes of lentigo maligna cases in the head and neck area treated by either WLE or ST in a tertiary referral hospital. The secondary goal was to describe the demographic and clinical characteristics of our series. METHODS: Cohort study of patients diagnosed with lentigo maligna on the head and neck region between January 2014 and February 2022 in a tertiary hospital. RESULTS: In total, 79 lentigo maligna were studied, corresponding to 77 patients. Fifty-three lesions (67%) were treated with WLE and 26 (33%) with ST. The mean age of the patients was 73 years and 58% were men. Most of the tumors were located on the cheek (50%) and mean lesion diameter was 2.2 cm for the ST group and 1.2 cm for the WLE group. Mean duration follow-up was 44 months. There were two local recurrences in the WLE group (2/53; 3.7%) and none in the ST group. CONCLUSIONS: Both WLE and ST are appropriate surgical approaches for lentigo maligna. ST offers an efficient alternative to Mohs surgery for treating lentigo maligna in the head and neck area, especially when guided by reflectance confocal microscopy.

Effects of experimental impairments on the security of continuous-variable quantum key distribution.

Quantum Key Distribution (QKD) is a cutting-edge communication method that enables secure communication between two parties. Continuous-variable QKD (CV-QKD) is a promising approach to QKD that has several advantages over traditional discrete-variable systems. Despite its potential, CV-QKD systems are highly sensitive to optical and electronic component impairments, which can significantly reduce the secret key rate. In this research, we address this challenge by modeling a CV-QKD system to simulate the impact of individual impairments on the secret key rate. The results show that laser frequency drifts and small imperfections in electro-optical devices such as the beam splitter and the balanced detector have a negative impact on the secret key rate. This provides valuable insights into strategies for optimizing the performance of CV-QKD systems and overcome limitations caused by component impairments. By offering a method to analyze them, the study enables the establishment of quality standards for the components of CV-QKD systems, driving the development of advanced technologies for secure communication in the future.

Functional interplay between Mediator and RSC chromatin remodeling complex controls nucleosome-depleted region maintenance at promoters.

Chromatin organization is crucial for transcriptional regulation in eukaryotes. Mediator is an essential and conserved co-activator thought to act in concert with chromatin regulators. However, it remains largely unknown how their functions are coordinated. Here, we provide evidence in the yeast Saccharomyces cerevisiae that Mediator establishes physical contact with RSC (Remodels the Structure of Chromatin), a conserved and essential chromatin remodeling complex that is crucial for nucleosome-depleted region (NDR) formation. We determine the role of Mediator-RSC interaction in their chromatin binding, nucleosome occupancy, and transcription on a genomic scale. Mediator and RSC co-localize on wide NDRs of promoter regions, and specific Mediator mutations affect nucleosome eviction and TSS-associated +1 nucleosome stability. This work shows that Mediator contributes to RSC remodeling function to shape NDRs and maintain chromatin organization on promoter regions. It will help in our understanding of transcriptional regulation in the chromatin context relevant for severe diseases.

Identification of Omega-class glutathione transferases in helminths of the Taeniidae family.

Glutathione transferase enzymes (GSTs) are believed to be a major detoxification system in helminth parasites and have been associated with immunomodulation of the host response. Echinococcus granulosus sensu lato (s.l.) is a cestode parasite known to express at least five different GSTs, but no Omega-class enzymes have been reported in this parasite or in any other cestode. Herein we report the identification of a new member of the GST superfamily in E. granulosus s.l., which is phylogenetically related to the Omega-class: EgrGSTO. Through mass spectrometry, we showed that the 237 amino acids protein EgrGSTO is expressed by the parasite. Moreover, we identified homologues of EgrGSTO in other eight members of the Taeniidae family, including E. canadensis, E. multilocularis, E. oligarthrus, Hydatigera taeniaeformis, Taenia asiatica, T. multiceps, T. saginata and T. solium. A manual sequence inspection and rational modification yielded eight Taeniidae's GSTO sequences, each one encoding for a 237 aa polypeptide showing 80.2% overall identity. To the best of our knowledge, this is the first description of genes encoding for Omega-class GSTs in worms belonging to the Taeniidae family -that at least in E. granulosus s.l. is expressed as a protein- suggesting the gene encodes for a functional protein.

Are Dyslexic People more Creative? Myth or Reality: A Meta-analysis / ¿Son las personas disléxicas más creativas? Mito o realidad: metaanálisis

The claim that people with dyslexia are more creative than people without this learning disorder is widespread. But the complexity of creativity and the way it is measured means that this statement is sometimes inconsistent. The aim of this review is, on the one hand, to explore the relationship between dyslexia and creativity, as well as to analyze the categories of divergent thinking: fluency, originality, abstractness, elaboration, and flexibility. On the other hand, it also aims to identify moderators that may be influencing this relationship, such as age, country, or the test used. We retrieved 13 empirical studies that provided 39 effect sizes. The results show that there are no significant differences between people with and without dyslexia in terms of creativity when considering the construct as a whole. However, a significant relationship between the two constructs is observed when analyzing the categories of divergent thinking isolated.(AU)

La afirmación de que las personas con dislexia son más creativas que las personas sin este trastorno específico del aprendizaje está muy extendida. Pero la complejidad del constructo de creatividad y la forma en que esta se mide, hace que esta afirmación sea contradictoria. El objetivo de esta revisión es doble; por un lado, pretende explorar la relación entre dislexia y creatividad, así como analizar las categorías del pensamiento divergente: fluidez, originalidad, abstracción, elaboración y flexibilidad; por otro, pretende identificar moderadores que puedan estar influyendo en esta relación, como la edad, el país o la prueba utilizada. Se recuperaron trece estudios empíricos, con un total de 39 tamaños de efecto. Los resultados muestran que no existen diferencias significativas en cuanto a la creatividad entre personas con dislexia y sin ella cuando se considera el constructo como un todo. Sin embargo, se observa una relación significativa entre ambos al analizar las categorías de pensamiento divergente de forma aislada.(AU)

Protección del ácido clorogénico frente a lesiones inducidas por venzo(a)pireno en Saccharomyces cerevisiae / Protection of chlorogenic acid against benzo(a)pyrene-induced lesions in Saccharomyces cerevisiae / Proteção do ácido clorogênico contra lesões induzidas por benzo(a)pireno em Saccharomyces cerevisiae

El objetivo del presente estudio fue analizar el efecto del ácido clorogénico, uno de los compuestos polifenólicos con mayor concentración en la infusión de Ilex paraguariensis, sobre el daño celular y molecular inducido por el benzo(a)pireno. La infusión de Ilex paraguariensis ("mate") es bebida por la mayoría de los habitantes de Argentina, Paraguay, sur de Brasil y Uruguay. La levadura Saccharomyces cerevisiae (cepas SC7K lys2-3; SX46A y SX46Arad14() se utilizó como modelo eucariota. Las células en crecimiento exponencial se expusieron a concentraciones crecientes de benzo(a)pireno y a tratamientos combinados con una concentración de 250 ng/mL de benzo(a)pireno y ácido clorogénico a una concentración igual a la encontrada en la infusión de yerba mate. Luego de los tratamientos se determinaron fracciones de sobrevida, frecuencia mutagénica y roturas de doble cadena de ADN así como la modulación en la expresión de la proteína Rad14 a través de un análisis de Western Blot. Se observó un aumento significativo en las fracciones de sobrevida así como una disminución en la frecuencia mutagénica después de la exposición combinada con benzo(a)pireno y ácido clorogénico en comparación con los tratamientos con benzo(a)pireno como único agente. En la cepa mutante deficiente en la proteína Rad14 se observó un aumento significativo en la sensibilidad a benzo(a)pireno en comparación con la cepa SC7K lys2-3. En los tratamientos combinados de benzo(a)pireno y ácido clorogénico se observó una importante disminución de la letalidad. Con respecto a la determinación de roturas de doble cadena de ADN no se observó fraccionamiento cromosómico a la concentración de benzo(a)pireno utilizada en los experimentos. Los análisis de Western Blot mostraron un aumento en la expresión de la proteína Rad14 en las muestras tratadas con benzo(a)pireno como único agente en comparación con la muestra control. Adicionalmente se observó una disminución en la expresión de la proteína cuando en los tratamientos se utilizaron benzo(a)pireno y ácido clorogénico combinados. Los resultados indican que el ácido clorogénico disminuye significativamente la actividad mutagénica producida por el benzo(a)pireno, la cual no se encuentra relacionada con un incremento en la remoción de las lesiones inducidas por el sistema de reparación por escisión de nucleótidos.

The aim of this study was to analyze the effect of chlorogenic acid, a polyphenolic compound found at high concentrations in Ilex paraguariensis infusions, on cellular and molecular damage induced by benzo(a)pyrene. Ilex paraguariensis infusions ("mate") are consumed by most of the population in Argentina, Paraguay, southern Brazil and Uruguay. Saccharomyces cerevisiae yeast (SC7K lys2-3; SX46A and SX46Arad14( strains) were used as eukaryotic model organisms. Cells in an exponential growth phase were exposed to increasing concentrations of benzo(a)pyrene, as well as combined treatments of benzo(a)pyrene at a concentration of 250 ng/mL and chlorogenic acid at a concentration matching that which is commonly found in mate. Determinations of surviving fraction, mutagenic frequency and double strand DNA breaks induction were performed, along with the assessment of the modulation of the expression of protein Rad14 by Western Blot. A significant increase of surviving fractions and a decrease in mutagenic frequency were observed after exposure to benzo(a)pyrene plus chlorogenic acid, contrary to benzo(a)pyrene alone. A substantial increase in sensitivity to benzo(a)pyrene was observed for the Rad14 protein-deficient mutating strain when compared to the SC7K lys2-3 strain. An important decrease in lethality was observed when combined benzo(a)pyrene and chlorogenic acid treatments were applied. As for the determination of DSBs, no chromosomic fractionation was observed at the benzo(a)pyrene concentration tested in the experiments. Western Blot analysis showed an increase in the expression of protein Rad14 for samples treated with benzo(a)pyrene as a single agent when compared against the control sample. Additionally, the expression of this protein was observed to diminish when combined treatments with benzo(a)pyrene and chlorogenic acid were used. Results obtained indicate that chlorogenic acid significantly decreases the mutagenic activity of benzo(a)pyrene, which is not related to an increase in the removal of lesions induced by nucleotide excision repair system.

O objetivo deste estudo foi analisar o efeito do ácido clorogênico, um dos compostos polifenólicos com maior concentração na infusão de Ilex paraguariensis, sobre o dano celular e molecular induzido pelo benzopireno. A infusão de Ilex paraguariensis ("mate") é consumida pela maioria dos habitantes da Argentina, Paraguai, sul do Brasil e Uruguai. A levedura Saccharomyces cerevisiae (cepas SC7K lys2-3; SX46A e SX46Arad14() foi utilizada como modelo eucariótico. Células em crescimento exponencial foram expostas a concentrações crescentes de benzopireno e tratamentos combinados foram realizados com uma concentração de 250 ng/mL de benzo(a)pireno e ácido clorogênico, igual à encontrada na infusão de erva-mate. Após os tratamentos, foram determinadas as frações de sobrevivência, frequência mutagênica e quebras de fita dupla do DNA, bem como a modulação na expressão da proteína Rad14 por meio de análise de Western Blot. Um aumento significativo nas frações de sobrevivência, bem como uma diminuição na frequência mutagênica foram observados após a exposição combinada de benzo(a)pireno e ácido clorogênico em comparação com tratamentos de agente único de benzo(a)pireno. Um aumento significativo na sensibilidade ao benzo(a)pireno foi observado na cepa mutante deficiente em proteína Rad14 em comparação com a cepa SC7K lys2-3. Nos tratamentos combinados de benzo(a)pireno e ácido clorogênico, observou-se uma diminuição significativa na letalidade. Com relação à determinação das quebras de fita dupla de DNA, não foi observado fracionamento cromossômico na concentração de benzo(a)pireno utilizada nos experimentos. A partir da análise de Western Blot, observou-se um aumento na expressão da proteína Rad14 nas amostras tratadas com benzo(a)pireno como agente único em relação à amostra controle. Além disso, uma diminuição na expressão da proteína foi observada quando combinados de benzo(a)pireno e ácido clorogênico foram usados ​​nos tratamentos. Os resultados obtidos neste trabalho indicam que o ácido clorogênico diminui significativamente a atividade mutagênica produzida pelo benzo(a)pireno, a qual não está relacionada a um aumento na remoção de lesões induzidas pelo sistema de reparo por excisão de nucleotídeos.