RESUMEN

This work introduces a new element-selective gas chromatography detector for the accurate quantification of traces of volatile oxygen-containing compounds in complex samples without the need for specific standards. The key to this approach is the use of oxygen highly enriched in 18O as the oxidizing gas in a combustion unit (800 °C) that allows us to directly and unambiguously detect the natural oxygen present in the GC-separated compounds through its incorporation into the volatile species formed after their combustion and their subsequent degradation to 16O in the ion source. The unspecific signal due to the low 16O abundance in the oxidizing gas could be compensated by measuring the m/z 12 that comes as well from the CO2 degradation. Equimolarity was proved with several O-containing compounds with different sizes and functionalities. A detection limit of 28 pg of injected O was achieved, which is the lowest ever reported for any GC detector, which barely worsened to 55 and 214 pg of O when the oxygenate partially or completely coeluted with a very abundant matrix compound. Validation was attained by the analysis of a SRM to obtain accurate (99-103%) and precise (1-4% RSD) results. Robustness was tested after spiking a hydrotreated diesel with 10 O-compounds at the ppm level, which could be discriminated from the matrix crowd and quantified (mean recovery of 102 ± 9%) with a single generic standard. Finally, it was also successfully applied to easily spot and quantify the 33 oxygenates naturally present in a complex wood bio-oil sample.

RESUMEN

Here, we show the potential and applicability of the novel GC-combustion-MS approach as a nitrogen-selective GC detector. Operating requirements to achieve reproducible and compound-independent formation of volatile NO species as a selective N-signal during the combustion step are described. Specifically, high temperatures (≥1000 °C) and post-column O2 flows (0.4 mL min-1 of 0.3% O2 in He) turned out to be necessary when using a vertical oven without makeup flow (prototype #1). In contrast, the use of a horizontal oven with 1.7 mL min-1 He as an additional makeup flow (prototype #2) required milder conditions (850 °C and 0.2 mL min-1). A detection limit of 0.02 pg of N injected was achieved, which is by far the lowest ever reported for any GC detector. Equimolarity, linearity, and peak shape were also adequate. Validation of the approach was performed by the analysis of a certified reference material obtaining accurate (2% error) and precise (2% RSD) results. Robustness was tested with the analysis of two complex samples with different matrices (diesel and biomass pyrolysis oil) and N concentration levels. Total N determined after the integration of the whole chromatograms (524 ± 22 and 11,140 ± 330 µg N g-1, respectively) was in good agreement with the reference values (497 ± 10 and 11,000 ± 1200 µg N g-1, respectively). In contrast, GC-NCD results were lower for the diesel sample (394 ± 42 µg N g-1). Quantitative values for the individual and families of N species identified in the real samples by parallel GC-MS and additional GC × GC-MS analyses were also obtained using a single generic internal standard.

RESUMEN

PURPOSE: To assess health-related quality of life (HRQoL) and its associated factors in patients who survived COVID-19 and to assess a prospective evaluation of the prevalence and severity of their depression and anxiety symptoms. METHODS: We followed up a sample of hospitalized patients who survived COVID-19 at 3 and 12 months after discharge. We assessed HRQoL (Euroqol-5D-5L) through telephone interviews. Any problem in any dimension of Euroqol-5D-5L was considered as low HRQoL. The depression and anxiety symptoms were measured using the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7 tools, respectively. We estimated the adjusted prevalence ratios (aPR) to low HRQoL using Poisson regression and the changes on their depression and anxiety symptoms during the follow-up. RESULTS: We included 119 patients with a mean follow-up time of 363.6 days. 74% of the participants had low HRQoL at one year after hospital discharge and were associated with being ≥ 41 years old (aPR: 1.95), having a previous history of psychiatric diagnoses before COVID-19 infection (aPR: 1.47), having any COVID-19 symptom during the follow-up at one year (aPR: 1.84), and having a family member who had died from COVID-19 during the first wave (aPR: 1.24). In addition, the clinically relevant depression symptoms were frequent, and they increased from 3 (14.3%) to 12 months (18.5%). CONCLUSION: One year after COVID-19 hospitalization discharge, patients had low HRQoL, and their depression symptoms increased. These findings acknowledge the need to provide services that adequately address mental health sequels and HRQoL to reduce the burden of the COVID-19.

Asunto(s)

COVID-19 , Calidad de Vida , Humanos , Adulto , Calidad de Vida/psicología , Depresión/psicología , Estudios de Seguimiento , Perú/epidemiología , COVID-19/epidemiología , Ansiedad/epidemiología , Ansiedad/psicología , Trastornos de Ansiedad/epidemiología , Encuestas y Cuestionarios

RESUMEN

Colchicine has been used to treat gout and, more recently, to effectively prevent autoinflammatory diseases and both primary and recurrent episodes of pericarditis. The anti-inflammatory action of colchicine seems to result from irreversible inhibition of tubulin polymerization and microtubule (MT) assembly by binding to the tubulin heterodimer, avoiding the signal transduction required to the activation of the entire NLRP3 inflammasome. Emerging results show that the MT network is a potential regulator of cardiac mechanics. Here, we investigated how colchicine impacts in tubulin folding cofactors TBCA, TBCB, and TBCE activities. We show that TBCA is abundant in mouse heart insoluble protein extracts. Also, a decrease of the TBCA/ß-tubulin complex followed by an increase of free TBCA is observed in human cells treated with colchicine. The presence of free TBCA is not observed in cells treated with other anti-mitotic agents such as nocodazole or cold shock, neither after translation inhibition by cycloheximide. In vitro assays show that colchicine inhibits tubulin heterodimer dissociation by TBCE/TBCB, probably by interfering with interactions of TBCE with tubulin dimers, leading to free TBCA. Manipulation of TBCA levels, either by RNAi or overexpression results in decreased levels of tubulin heterodimers. Together, these data strongly suggest that TBCA is mainly receiving ß-tubulin from the dissociation of pre-existing heterodimers instead of newly synthesized tubulins. The TBCE/TBCB+TBCA system is crucial for controlling the critical concentration of free tubulin heterodimers and MT dynamics in the cells by recycling the tubulin heterodimers. It is conceivable that colchicine affects tubulin heterodimer recycling through the TBCE/TBCB+TBCA system producing the known benefits in the treatment of pericardium inflammation.

RESUMEN

We present a novel and single detection approach that enables sensitive, accurate and compound-independent quantification of N, S and H in the individual compounds present in complex samples. Integration of the whole chromatographic profile gives the total content of the elements. Simultaneous universal detection is also achieved using the C profile.

RESUMEN

Atrazine (ATR) continues being one of the most frequently detected pesticides in natural waters and soils. In this work, an electrokinetic-assisted phytoremediation pot test (EKPR) was performed for the remediation of an atrazine-spiked soil; a low electric voltage gradient (1 V cm-1) with two different electric field operation times (6 and 24 h per day) was used in combination with ryegrass (Lolium perenne L.). EKPR increased up to 27% and 7% the overall ATR removal from soil as compared to natural attenuation and phytoremediation treatments, respectively. ATR soil concentration vs time curves were fitted to a pseudofirst-order kinetic equation, obtaining ATR half-life values of 8.2, 7.1 and 5.4 days for the treatments corresponding, respectively, to 0, 6 and 24 h day-1 of electric current application. It clearly showed that the ATR removal from soils was enhanced by the electric field. ATR plant accumulation was significantly improved with respect to phytoremediation when the electric current was continuously applied throughout the experiment (24 h day-1); most of the ATR residues were accumulated in the shoot biomass of the ryegrass plants.

Asunto(s)

Atrazina/metabolismo , Biodegradación Ambiental , Lolium/fisiología , Contaminantes del Suelo/metabolismo , Atrazina/análisis , Biomasa , Cinética , Suelo/química , Contaminantes del Suelo/análisis

RESUMEN

Quantitative characterization of sulfur-containing petroleum derivatives is mainly limited by the large number of potential targets present and the matrix effects suffered due to the high-carbon-containing matrices. Herein we describe the instrumental modifications required in a commercial GC-ICP-MS/MS instrument, and their corresponding optimization, for turning it into a compound-independent quantitative technique for both total and speciation sulfur analysis in gasolines. Additionally, carbon-derived matrix effects were made negligible for direct and fast total S analysis, making the use of relatively complex isotope-dilution strategies not necessary anymore. An absolute detection limit of 0.3 pg of S was achieved, which is, to the best of our knowledge, more than 1 order of magnitude below the ones reported for other sulfur GC selective detectors. The precision was below 3% RSD. Total analysis was performed by flow-injection analysis through a transfer line and external calibration, whereas speciation analysis was carried out by chromatographic separation and internal standardization. In both cases, simple generic standards were used, which enabled us to get rid of specific S-containing standards, which were sometimes not available or unstable. The proposed method was successfully applied to total and speciation sulfur analysis of a commercial gasoline sample and validated with a certified-reference-material (ERM-EF213) gasoline. The approach has proved to be simple, fast, robust, and convenient for implementation in routine laboratories, as demonstrated by the successive analyses of 50 gasoline samples in 3 h without any instrumental drift.

RESUMEN

BACKGROUND: Recently, long noncoding RNAs have emerged as pivotal molecules for the regulation of coding genes' expression. These molecules might result from antisense transcription of functional genes originating natural antisense transcripts (NATs) or from transcriptional active pseudogenes. TBCA interacts with ß-tubulin and is involved in the folding and dimerization of new tubulin heterodimers, the building blocks of microtubules. METHODOLOGY/PRINCIPAL FINDINGS: We found that the mouse genome contains two structurally distinct Tbca genes located in chromosomes 13 (Tbca13) and 16 (Tbca16). Interestingly, the two Tbca genes albeit ubiquitously expressed, present differential expression during mouse testis maturation. In fact, as testis maturation progresses Tbca13 mRNA levels increase progressively, while Tbca16 mRNA levels decrease. This suggests a regulatory mechanism between the two genes and prompted us to investigate the presence of the two proteins. However, using tandem mass spectrometry we were unable to identify the TBCA16 protein in testis extracts even in those corresponding to the maturation step with the highest levels of Tbca16 transcripts. These puzzling results led us to re-analyze the expression of Tbca16. We then detected that Tbca16 transcription produces sense and natural antisense transcripts. Strikingly, the specific depletion by RNAi of these transcripts leads to an increase of Tbca13 transcript levels in a mouse spermatocyte cell line. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that Tbca13 mRNA levels are post-transcriptionally regulated by the sense and natural antisense Tbca16 mRNA levels. We propose that this regulatory mechanism operates during spermatogenesis, a process that involves microtubule rearrangements, the assembly of specific microtubule structures and requires critical TBCA levels.

Asunto(s)

Regulación del Desarrollo de la Expresión Génica , Proteínas Asociadas a Microtúbulos/genética , Chaperonas Moleculares/genética , ARN sin Sentido/genética , ARN no Traducido/metabolismo , Testículo/crecimiento & desarrollo , Testículo/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Cromosomas de los Mamíferos/genética , Técnicas de Silenciamiento del Gen , Genoma/genética , Masculino , Ratones , Proteínas Asociadas a Microtúbulos/química , Proteínas Asociadas a Microtúbulos/metabolismo , Modelos Moleculares , Chaperonas Moleculares/química , Chaperonas Moleculares/metabolismo , Datos de Secuencia Molecular , ARN sin Sentido/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN no Traducido/genética , Espermatocitos/metabolismo , Espermatogénesis/genética , Transcripción Genética

RESUMEN

Microtubule-organizing centers recruit alpha- and beta-tubulin polypeptides for microtubule nucleation. Tubulin synthesis is complex, requiring five specific cofactors, designated tubulin cofactors (TBCs) A-E, which contribute to various aspects of microtubule dynamics in vivo. Here, we show that tubulin cofactor D (TBCD) is concentrated at the centrosome and midbody, where it participates in centriologenesis, spindle organization, and cell abscission. TBCD exhibits a cell-cycle-specific pattern, localizing on the daughter centriole at G1 and on procentrioles by S, and disappearing from older centrioles at telophase as the protein is recruited to the midbody. Our data show that TBCD overexpression results in microtubule release from the centrosome and G1 arrest, whereas its depletion produces mitotic aberrations and incomplete microtubule retraction at the midbody during cytokinesis. TBCD is recruited to the centriole replication site at the onset of the centrosome duplication cycle. A role in centriologenesis is further supported in differentiating ciliated cells, where TBCD is organized into "centriolar rosettes". These data suggest that TBCD participates in both canonical and de novo centriolar assembly pathways.

Asunto(s)

Ciclo Celular , Centriolos , Proteínas Asociadas a Microtúbulos/fisiología , Huso Acromático , Animales , Citometría de Flujo , Células HeLa , Humanos , Inmunohistoquímica , Ratones , Microscopía Confocal , Interferencia de ARN

RESUMEN

Microtubules are polymers of alpha/beta-tubulin participating in essential cell functions. A multistep process involving distinct molecular chaperones and cofactors produces new tubulin heterodimers competent to polymerise. In vitro cofactor A (TBCA) interacts with beta-tubulin in a quasi-native state behaving as a molecular chaperone. We have used siRNA to silence TBCA expression in HeLa and MCF-7 mammalian cell lines. TBCA is essential for cell viability and its knockdown produces a decrease in the amount of soluble tubulin, modifications in microtubules and G1 cell cycle arrest. In MCF-7 cells, cell death was preceded by a change in cell shape resembling differentiation.

Asunto(s)

Apoptosis , Ciclo Celular , Proteínas Asociadas a Microtúbulos/fisiología , Microtúbulos/metabolismo , Chaperonas Moleculares/fisiología , Citoesqueleto de Actina/metabolismo , Apoptosis/efectos de los fármacos , Caspasa 7 , Caspasas/metabolismo , Ciclo Celular/efectos de los fármacos , Fase G1/efectos de los fármacos , Fase G1/genética , Silenciador del Gen , Células HeLa , Humanos , Proteínas Asociadas a Microtúbulos/genética , Chaperonas Moleculares/genética , Fenotipo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/farmacología , Tubulina (Proteína)/metabolismo