RESUMEN
Genetic information in the cell nucleus controls organismal development and responses to the environment, and finally ensures its own transmission to the next generations. To achieve so many different tasks, the genetic information is associated with structural and regulatory proteins, which orchestrate nuclear functions in time and space. Furthermore, plant life strategies require chromatin plasticity to allow a rapid adaptation to abiotic and biotic stresses. Here, we summarize current knowledge on the organization of plant chromatin and dynamics of chromosomes during interphase and mitotic and meiotic cell divisions for model and crop plants differing as to genome size, ploidy, and amount of genomic resources available. The existing data indicate that chromatin changes accompany most (if not all) cellular processes and that there are both shared and unique themes in the chromatin structure and global chromosome dynamics among species. Ongoing efforts to understand the molecular mechanisms involved in chromatin organization and remodeling have, together with the latest genome editing tools, potential to unlock crop genomes for innovative breeding strategies and improvements of various traits.
Asunto(s)
Cromatina , Fitomejoramiento , División Celular , Cromatina/genética , Cromosomas , InterfaseRESUMEN
In this work, the process performance of three parallel anaerobic digesters was evaluated while treating emulsified long-chain fatty acids (LCFA) (i.e., palmitic, stearic and oleic acid) at two different organic loading rates (OLR) (2 and 4 g L-1 day-1). The digester treating palmitic acid achieved a biogas yield of 0.42 ± 0.05 L g-1 COD with a digester effluent COD of 2.3 ± 0.4 g L-1 and VFA concentrations below 250 mg L-1. Stearic acid showed lower biogas yield values (0.34 ± 0.05 L g-1 COD) with low effluent COD (2.5 ± 0.4 g L-1) and VFA concentrations (< 350 mg L-1). On the contrary, anaerobic digestion of oleic acid was accompanied with increased effluent COD (4.5 ± 0.7 g L-1) and VFA concentrations (2.7 ± 1.5 g L-1). As such, COD removal efficiency remained at 89 ± 1% compared to 95 ± 1% for the digesters treating palmitic and stearic acid. During continuous digester operation, there was a decrease in VFA concentrations (around 1-2 g L-1), combined with increasing biogas yield values up to 0.51 ± 0.04 L g-1 COD, possibly due to biomass adaptation to oleic acid. Digester foaming was recorded when the accumulated COD was higher than 200, 1200 and 500 mg COD g-1 MLSS for the digester treating palmitic, stearic and oleic acid, respectively. ADM1 simulation allowed for the determination of the maximum specific LCFA consumption rate constant (km) which was equal to 4.8, 1.6 and 8.0 day-1 for palmitic, stearic and oleic acid respectively.
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Ácidos Grasos/química , Modelos Teóricos , Ácido Oléico/química , Ácido Palmítico/química , Ácidos Esteáricos/química , Anaerobiosis , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos , Concentración de Iones de Hidrógeno , Cinética , TemperaturaRESUMEN
Reproduction success in angiosperm plants depends on robust pollen tube growth through the female pistil tissues to ensure successful fertilization. Accordingly, there is an apparent evolutionary trend to accumulate significant reserves during pollen maturation, including a population of stored mRNAs, that are utilized later for a massive translation of various proteins in growing pollen tubes. Here, we performed a thorough transcriptomic and proteomic analysis of stored and translated transcripts in three subcellular compartments of tobacco (Nicotiana tabacum), long-term storage EDTA/puromycin-resistant particles, translating polysomes, and free ribonuclear particles, throughout tobacco pollen development and in in vitro-growing pollen tubes. We demonstrated that the composition of the aforementioned complexes is not rigid and that numerous transcripts were redistributed among these complexes during pollen development, which may represent an important mechanism of translational regulation. Therefore, we defined the pollen sequestrome as a distinct and highly dynamic compartment for the storage of stable, translationally repressed transcripts and demonstrated its dynamics. We propose that EDTA/puromycin-resistant particle complexes represent aggregated nontranslating monosomes as the primary mediators of messenger RNA sequestration. Such organization is extremely useful in fast tip-growing pollen tubes, where rapid and orchestrated protein synthesis must take place in specific regions.
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Perfilación de la Expresión Génica/métodos , Polen/genética , Polen/metabolismo , Proteómica/métodos , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Polen/crecimiento & desarrollo , Tubo Polínico/genética , Tubo Polínico/crecimiento & desarrollo , Tubo Polínico/metabolismo , Polirribosomas/genética , Polirribosomas/metabolismo , Proteoma/genética , Proteoma/metabolismo , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Ribosomas/genética , Ribosomas/metabolismo , Nicotiana/genética , Nicotiana/crecimiento & desarrollo , Nicotiana/metabolismoRESUMEN
BACKGROUND: Candida auris was sporadically detected in Greece until 2019. Thereupon, there has been an increase in isolations among inpatients of healthcare facilities. AIM: We aim to report active surveillance data on MALDI-TOF confirmed Candida auris cases and outbreaks, from November 2019 to September 2021. METHODS: A retrospective study on hospital-based Candida auris data, over a 23-month period was conducted, involving 11 hospitals within Attica region. Antifungal susceptibility testing and genotyping were conducted. Case mortality and fatality rates were calculated and p-values less than 0.05 were considered statistically significant. Infection control measures were enforced and enhanced. RESULTS: Twenty cases with invasive infection and 25 colonized were identified (median age: 72 years), all admitted to hospitals for reasons other than fungal infections. Median hospitalisation time until diagnosis was 26 days. Common risk factors among cases were the presence of indwelling devices (91.1 %), concurrent bacterial infections during hospitalisation (60.0 %), multiple antimicrobial drug treatment courses prior to hospitalisation (57.8 %), and admission in the ICU (44.4 %). Overall mortality rate was 53 %, after a median of 41.5 hospitalisation days. Resistance to fluconazole and amphotericin B was identified in 100 % and 3 % of tested clinical isolates, respectively. All isolates belonged to South Asian clade I. Outbreaks were identified in six hospitals, while remaining hospitals detected sporadic C. auris cases. CONCLUSION: Candida auris has proven its ability to rapidly spread and persist among inpatients and environment of healthcare facilities. Surveillance focused on the presence of risk factors and local epidemiology, and implementation of strict infection control measures remain the most useful interventions.
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Antifúngicos , Candida auris , Candidiasis , Infección Hospitalaria , Brotes de Enfermedades , Pruebas de Sensibilidad Microbiana , Humanos , Grecia/epidemiología , Anciano , Brotes de Enfermedades/estadística & datos numéricos , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Anciano de 80 o más Años , Antifúngicos/uso terapéutico , Antifúngicos/farmacología , Candidiasis/epidemiología , Candidiasis/microbiología , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Candida auris/genética , Adulto , Hospitales/estadística & datos numéricos , Instituciones de Salud/estadística & datos numéricos , Control de Infecciones , Factores de Riesgo , Farmacorresistencia Fúngica , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Candida/aislamiento & purificación , Candida/efectos de los fármacos , Candida/clasificación , Hospitalización/estadística & datos numéricosRESUMEN
Sexual reproduction in angiosperms requires the production and delivery of two male gametes by a three-celled haploid male gametophyte. This demands synchronized gene expression in a short developmental window to ensure double fertilization and seed set. While transcriptomic changes in developing pollen are known for Arabidopsis, no studies have integrated RNA and proteomic data in this model. Further, the role of alternative splicing has not been fully addressed, yet post-transcriptional and post-translational regulation may have a key role in gene expression dynamics during microgametogenesis. We have refined and substantially updated global transcriptomic and proteomic changes in developing pollen for two Arabidopsis accessions. Despite the superiority of RNA-seq over microarray-based platforms, we demonstrate high reproducibility and comparability. We identify thousands of long non-coding RNAs as potential regulators of pollen development, hundreds of changes in alternative splicing and provide insight into mRNA translation rate and storage in developing pollen. Our analysis delivers an integrated perspective of gene expression dynamics in developing Arabidopsis pollen and a foundation for studying the role of alternative splicing in this model.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Reproducibilidad de los Resultados , Proteómica , Polen/genética , Polen/metabolismo , Transcriptoma , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Regulation of translation represents a critical step in the regulation of gene expression. In plants, the translation regulation plays an important role at all stages of development and, during stress responses, functions as a fast and flexible tool which not only modulates the global translation rate but also controls the production of specific proteins. Regulation of translation is mostly focused on the initiation phase. There, one of essential initiation factors is the large multisubunit protein complex of eukaryotic translation initiation factor 3 (eIF3). In all eukaryotes, the general eIF3 function is to scaffold the formation of the translation initiation complex and to enhance the accuracy of scanning mechanism for start codon selection. Over the past decades, additional eIF3 functions were described as necessary for development in various eukaryotic organisms, including plants. The importance of the eIF3 complex lies not only at the global level of initiation event, but also in the precise translation regulation of specific transcripts. This review gathers the available information on functions of the plant eIF3 complex.
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Factor 3 de Iniciación Eucariótica , Regulación de la Expresión Génica de las Plantas , Codón Iniciador , Factor 3 de Iniciación Eucariótica/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Plantas/genética , Biosíntesis de Proteínas/genéticaRESUMEN
KEY MESSAGE : bZIP TF network in pollen. Transcriptional control of gene expression represents an important mechanism guiding organisms through developmental processes and providing plasticity towards environmental stimuli. Because of their sessile nature, plants require effective gene regulation for rapid response to variation in environmental and developmental conditions. Transcription factors (TFs) provide such control ensuring correct gene expression in spatial and temporal manner. Our work reports the interaction network of six bZIP TFs expressed in Arabidopsis thaliana pollen and highlights the potential functional role for AtbZIP18 in pollen. AtbZIP18 was shown to interact with three other pollen-expressed bZIP TFs-AtbZIP34, AtbZIP52, and AtbZIP61 in yeast two-hybrid assays. AtbZIP18 transcripts are highly expressed in pollen, and at the subcellular level, an AtbZIP18-GFP fusion protein was located in the nucleus and cytoplasm/ER. To address the role of AtbZIP18 in the male gametophyte, we performed phenotypic analysis of a T-DNA knockout allele, which showed slightly reduced transmission through the male gametophyte. Some of the phenotype defects in atbzip18 pollen, although observed at low penetrance, were similar to those seen at higher frequency in the T-DNA knockout of the interacting partner, AtbZIP34. To gain deeper insight into the regulatory role of AtbZIP18, we analysed atbzip18/- pollen microarray data. Our results point towards a potential repressive role for AtbZIP18 and its functional redundancy with AtbZIP34 in pollen.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Polen/metabolismo , Arabidopsis/citología , Arabidopsis/ultraestructura , ADN de Plantas , Dimerización , Regulación de la Expresión Génica de las Plantas , Mutagénesis Insercional , Polen/genética , Polen/crecimiento & desarrollo , Polen/ultraestructura , Unión Proteica , Proteínas Recombinantes de Fusión/metabolismo , Transactivadores/metabolismoRESUMEN
BACKGROUND: Some patients with HIV/tuberculosis (TB) coinfection who are on anti-TB treatment and highly active antiretroviral therapy (HAART) will develop an exacerbation of symptoms, signs or radiological manifestations of TB that are not due to relapse or recurrence of their TB. The aetiology of these immune reconstitution inflammatory syndrome (IRIS) reactions is unknown but it is presumed that they occur, at least in part, as a consequence of HAART-related reconstitution of immunity. METHODS: Patients who were diagnosed with their first episode of definitive or presumed TB between January 2001 and July 2003 were identified from the Chelsea and Westminster TB/HIV database. The patients were classified into those who developed IRIS and those who did not using a set definition of the syndrome. Demographic, clinical and laboratory data relating to both HIV and TB were compared between the two groups. RESULTS: A total of 55 cases of TB were identified, of which 45 cases were confirmed on culture or gene probe and 10 were presumed cases. Fourteen cases (25.5%) developed IRIS with a median (range) duration of 2.53 (0.53-14.97) months. The median baseline CD4 [interquartile range (IQR)] for the IRIS group was significantly lower at 80 (33-117) cells/mm3 (P = 0.05) than the non-IRIS group at 139 (77-284) cells/mm3. A significantly greater proportion of patients in the IRIS group [11/14 (78.60%), P = 0.011] had baseline CD4 < 100cells/mm3 compared with the non-IRIS group [16/41 (39.0%)]. There was no significant difference between the two groups when comparing the log10 baseline viral load (VL). Eight (57.0%) patients in the IRIS group had disseminated TB at baseline compared with seven (17.0%) in the non-IRIS group (P = 0.006). In those who had a detectable VL at baseline, the median fold change (IQR) in CD4 from baseline to 3 months was significantly higher in the IRIS group patients, 1.5 (0.6-5.6), compared with 0.7 (-0.2 to 1.0) for those in the non-IRIS group (P = 0.046). CONCLUSIONS: Patients who develop IRIS are more likely to present with disseminated TB, have a CD4 count < 100 cells/mm3 and have a prompt rise in CD4 count in the initial 3 months of HAART.
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Terapia Antirretroviral Altamente Activa/efectos adversos , Infecciones por VIH/complicaciones , Infecciones por VIH/inmunología , Tuberculosis/inmunología , Adulto , Antituberculosos/uso terapéutico , Femenino , Infecciones por VIH/tratamiento farmacológico , Humanos , Inmunidad/efectos de los fármacos , Inflamación/etiología , Masculino , Persona de Mediana Edad , Síndrome , Factores de Tiempo , Tuberculosis/complicaciones , Tuberculosis/tratamiento farmacológicoRESUMEN
PURPOSE: Interprofessional collaboration in health care is believed to enhance patient outcomes. However, where professions have overlapping scopes of practice (eg, chiropractors and physical therapists), "turf wars" can hinder effective collaboration. Deep-rooted beliefs, identified as implicit attitudes, provide a potential explanation. Even with positive explicit attitudes toward a social group, negative stereotypes may be influential. Previous studies on interprofessional attitudes have mostly used qualitative research methodologies. This study used quantitative methods to evaluate explicit and implicit attitudes of physical therapy students toward chiropractic. METHODS: A paper-and-pencil instrument was developed and administered to 49 individuals (students and faculty) associated with a Canadian University master's entry-level physical therapy program after approval by the Research Ethics Board. The instrument evaluated explicit and implicit attitudes toward the chiropractic profession. Implicit attitudes were determined by comparing response times of chiropractic paired with positive versus negative descriptors. RESULTS: Mean time to complete a word association task was significantly longer (t = 4.75, p =.00) when chiropractic was associated with positive rather than negative words. Explicit and implicit attitudes were not correlated (r = 0.13, p =.38). CONCLUSIONS: While little explicit bias existed, individuals associated with a master's entry-level physical therapy program appeared to have a significant negative implicit bias toward chiropractic.
RESUMEN
Invasive hemodynamic monitoring with Swan-Ganz catheterization to guide treatment decisions in heart failure may be hazardous and may lack prognostic value. We assessed the clinical utility of B-type natriuretic peptide (BNP) in estimating left ventricular filling pressures in patients with inconclusive tissue Doppler indexes. In this study, 50 patients with systolic heart failure and an early transmitral velocity to early diastolic mitral annular velocity ratio (E/Ea) between 8 and 15 were studied. Among them, 25 had been admitted for acutely decompensated heart failure (group A) and the remainder were clinically stable outpatients (group B). All patients underwent simultaneous invasive pulmonary capillary wedge pressure (PCWP) determination, BNP measurement, and echocardiography. In group A, BNP correlated with PCWP (r = 0.803, P < 0.001), deceleration time (DT, r = -0.602, p = 0.001), and end-systolic wall stress (SWS, r = 0.565, P = 0.003). In multivariate analysis, BNP was the only parameter independently associated with PCWP (P = 0.023). In group B, no correlation was found between BNP and PCWP or SWS, while DT correlated significantly with both PCWP (r = -0.817, P < 0.001) and BNP (r = -0.8, P < 0.001). We conclude that BNP may be a useful noninvasive tool for the assessment of left ventricular filling pressures in patients with acutely decompensated heart failure and inconclusive tissue Doppler indexes.
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Ecocardiografía Doppler , Insuficiencia Cardíaca Sistólica/sangre , Péptido Natriurético Encefálico/sangre , Función Ventricular Izquierda , Presión Ventricular , Anciano , Biomarcadores/sangre , Femenino , Insuficiencia Cardíaca Sistólica/diagnóstico por imagen , Insuficiencia Cardíaca Sistólica/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Presión Esfenoidal PulmonarRESUMEN
BACKGROUND: Treatment failure during highly active antiretroviral therapy (HAART) is ultimately common and associated with the development of resistance mutations. Trizivir (zidovudine/lamivudine/abacavir) and tenofovir disoproxil fumarate may improve adherence and enhance virological suppression in individuals who have failed previous regimens. METHODS: Individuals were identified who had failed previous HAART and who were then prescribed trizivir and tenofovir. Viral load and genotypic information were obtained to assess virological response. RESULTS: One hundred and twenty-two individuals were identified from a database containing 5883 patients. In a last observation carried forward intention to treat analysis, 34% of individuals achieved an undetectable viral load of <50 copies/mL at 1 year. Of those who were able to remain on treatment for 1 year, 65% achieved undetectability. We observed no effect regarding previous regimens on viral outcome. Accumulation of TAMs (thymidine analogue mutations) was associated with a decrease in the number of patients achieving an undetectable viral load (with <2 TAMs present 38% of patients developed undetectable viral loads, > or =1;2 TAMs 17% undetectable; P = 0.03). Using the mean cell volume as a measure of compliance, those with higher values were more likely to achieve a viral load <50 copies/mL (P = 0.04). A beneficial effect on cholesterol was noted regardless of virological outcome. CONCLUSIONS: In compliant heavily pre-treated individuals with less than 2 TAMs, salvage therapy with trizivir and tenofovir is associated with suppression of viraemia and an improved lipid profile.