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BACKGROUND AND PURPOSE: Preoperative partial breast irradiation (PBI) is a novel technique that can be used in patients with early-stage breast cancer with the goal of limiting the irradiated breast volume, toxicity and number of fractions. The aim of this trial is to assess the toxicity, surgical, oncologic and cosmetic outcomes of preoperative PBI. MATERIALS AND METHODS: In this single-arm phase II trial, we enrolled women ≥ 60 years, with unifocal low-risk breast invasive ductal carcinoma (cT1N0, grade 1-2, ER+, Her2-). Patients were treated with a single fraction of 20 Gy of preoperative PBI using volumetric modulated arc therapy (VMAT). Patients then underwent breast-conserving surgery (BCS) +/- sentinel lymph node biopsy within 72 h of radiation. Primary outcomes were rate of surgical complications and early toxicity. Secondary outcomes were cosmesis at 12 months, chronic toxicity and ipsilateral breast tumor recurrence. RESULTS: Twenty-five patients were recruited with a median age of 67 years, and a median follow-up of 60 months. Sentinel biopsy was positive in 1 out of 24 patients (4 %). Two patients received adjuvant RT for close margins or positive lymph nodes. Within the first 90 days, none of the patients had surgical complications; almost all had grade 0 to 1 acute and late RTOG skin toxicity. The cosmetic outcome was rated between good and excellent in all cases by physicians and patients, except for one patient who self-rated her cosmesis as fair as of the third year. There were no recurrences. CONCLUSION: Preoperative single-fraction PBI is a safe and feasible treatment for elderly patients with low-risk early-stage breast cancer, with no surgical complications, very low rates of acute and late radiation toxicity, and excellent cosmetic outcomes. Randomized controlled trials are needed to compare preoperative to adjuvant PBI in this patient population.
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Electroactive biofilms formation by the metal-reducing bacterium Geobacter sulfurreducens is a step crucial for bioelectricity generation and bioremediation. The transcriptional regulator GSU1771 controls the expression of essential genes involved in electron transfer and biofilm formation in G. sulfurreducens, with GSU1771-deficient producing thicker and more electroactive biofilms. Here, RNA-seq analyses were conducted to compare the global gene expression patterns of wild-type and Δgsu1771 mutant biofilms grown on non-conductive (glass) and conductive (graphite electrode) materials. The Δgsu1771 biofilm grown on the glass surface exhibited 467 differentially expressed (DE) genes (167 upregulated and 300 downregulated) versus the wild-type biofilm. In contrast, the Δgsu1771 biofilm grown on the graphite electrode exhibited 119 DE genes (79 upregulated and 40 downregulated) versus the wild-type biofilm. Among these DE genes, 67 were also differentially expressed in the Δgsu1771 biofilm grown on glass (56 with the same regulation and 11 exhibiting counter-regulation). Among the upregulated genes in the Δgsu1771 biofilms, we identified potential target genes involved in exopolysaccharide synthesis (gsu1961-63, gsu1959, gsu1972-73, gsu1976-77). RT-qPCR analyses were then conducted to confirm the differential expression of a selection of genes of interest. DNA-protein binding assays demonstrated the direct binding of the GSU1771 regulator to the promoter region of pgcA, pulF, relA, and gsu3356. Furthermore, heme-staining and western blotting revealed an increase in c-type cytochromes including OmcS and OmcZ in Δgsu1771 biofilms. Collectively, our findings demonstrated that GSU1771 is a global regulator that controls extracellular electron transfer and exopolysaccharide synthesis in G. sulfurreducens, which is crucial for electroconductive biofilm development.
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Geobacter , Grafito , Grafito/metabolismo , Transporte de Electrón/genética , Biopelículas , Citocromos/metabolismo , Geobacter/metabolismo , Electrodos , Oxidación-ReducciónRESUMEN
We analyzed the global expression patterns of telomerase-negative mutants from haploid cells of Ustilago maydis to identify the gene network required for cell survival in the absence of telomerase. Mutations in either of the telomerase core subunits (trt1 and ter1) of the dimorphic fungus U. maydis cause deficiencies in teliospore formation. We report the global transcriptome analysis of two ter1Δ survivor strains of U. maydis, revealing the deregulation of telomerase-deleted responses (TDR) genes, such as DNA-damage response, stress response, cell cycle, subtelomeric, and proximal telomere genes. Other differentially expressed genes (DEGs) found in the ter1Δ survivor strains were related to pathogenic lifestyle factors, plant-pathogen crosstalk, iron uptake, meiosis, and melanin synthesis. The two ter1Δ survivors were phenotypically comparable, yet DEGs were identified when comparing these strains. Our findings suggest that teliospore formation in U. maydis is controlled by key pathogenic lifestyle and meiosis genes.
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The RNA subunit of telomerase is an essential component whose primary sequence and length are poorly conserved among eukaryotic organisms. The phytopathogen Ustilago maydis is a dimorphic fungus of the order Ustilaginales. We analyzed several species of Ustilaginales to computationally identify the TElomere RNA (TER) gene ter1. To confirm the identity of the TER gene, we disrupted the gene and characterized telomerase-negative mutants. Similar to catalytic TERT mutants, ter1Δ mutants exhibit phenotypes of growth delay, telomere shortening and low replicative potential. ter1-disrupted mutants were unable to infect maize seedlings in heterozygous crosses and showed defects such as cell cycle arrest and segregation failure. We concluded that ter1, which encodes the TER subunit of the telomerase of U. maydis, have similar and perhaps more extensive functions than trt1.
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Telomerasa , Ustilaginales , Ustilago , Animales , Telomerasa/genética , Telomerasa/metabolismo , Ustilaginales/genética , ARN/metabolismo , Estadios del Ciclo de Vida , Ustilago/genética , Ustilago/metabolismoRESUMEN
Background: Phonotimpus pennimani (Araneae, Phrurolithidae) is a small-sized (3-5 mm) spider endemic to the Tacaná volcano in Chiapas, Mexico, where it is found in soil litter of cloud forests and coffee plantations. Its venom composition has so far not been investigated, partly because it is not a species of medical significance. However, it does have an important impact on the arthropod populations of its natural habitat. Methods: Specimens were collected in Southeastern Mexico (Chiapas) and identified taxonomically by morphological characteristics. A partial sequence from the mitochondrial gene coxI was amplified. Sequencing on the Illumina platform of a transcriptome library constructed from 12 adult specimens revealed 25 toxin or toxin-like genes. Transcripts were validated (RT-qPCR) by assessing the differential expression of the toxin-like PpenTox1 transcript and normalising with housekeeping genes. Results: Analysis of the coxI-gene revealed a similarity to other species of the family Phrurolithidae. Transcriptome analysis also revealed similarity with venom components of species from the families Ctenidae, Lycosidae, and Sicariidae. Expression of the toxin-like PpenTox1 gene was different for each developmental stage (juvenile or adult) and also for both sexes (female or male). Additionally, a partial sequence was obtained for the toxin-like PpenTox1 from DNA. Conclusion: Data from the amplification of the mitochondrial coxI gene confirmed that P. pennimani belongs to the family Phrurolithidae. New genes and transcripts coding for venom components were identified.
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Klebsiella sp. strain AqSCr, isolated from Cr(VI)-polluted groundwater, reduces Cr(VI) both aerobically and anaerobically and resists up 34 mM Cr(VI); this resistance is independent of the ChrA efflux transporter. In this study, we report the whole genome sequence and the transcriptional profile by RNA-Seq of strain AqSCr under Cr(VI)-adapted conditions and found 255 upregulated and 240 downregulated genes compared to controls without Cr(VI) supplementation. Genes differentially transcribed were mostly associated with oxidative stress response, DNA repair and replication, sulfur starvation response, envelope-osmotic stress response, fatty acid (FA) metabolism, ribosomal subunits, and energy metabolism. Among them, genes not previously associated with chromium resistance, for example, cybB, encoding a putative superoxide oxidase (SOO), gltA2, encoding an alternative citrate synthase, and des, encoding a FA desaturase, were upregulated. The sodA gene encoding a manganese superoxide dismutase was upregulated in the presence of Cr(VI), whereas sodB encoding an iron superoxide dismutase was downregulated. Cr(VI) resistance mechanisms in strain AqSCr seem to be orchestrated by the alternative sigma factors fecl, rpoE, and rpoS (all of them upregulated). Membrane lipid analysis of the Cr(IV)-adapted strain showed a lower proportion of unsaturated lipids with respect to the control, which we hypothesized could result from unsaturated lipid peroxidation followed by degradation, together with de novo synthesis mediated by the upregulated FA desaturase-encoding gene, des. This report helps to elucidate both Cr(VI) toxicity targets and global bacterial response to Cr(VI).
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Integration host factor (IHF) is a widely distributed small heterodimeric protein member of the bacterial Nucleoid-Associated Proteins (NAPs), implicated in multiple DNA regulatory processes. IHF recognizes a specific DNA sequence and induces a large bend of the nucleic acid. IHF function has been mainly linked with the regulation of RpoN-dependent promoters, where IHF commonly recognizes a DNA sequence between the enhancer-binding region and the promoter, facilitating a close contact between the upstream bound activator and the promoter bound, RNA polymerase. In most proteobacteria, the genes encoding IHF subunits (ihfA and ihfB) are found in a single copy. However, in some Deltaproteobacteria, like Geobacter sulfurreducens, those genes are duplicated. To date, the functionality of IHF reiterated encoding genes is unknown. In this work, we achieved the functional characterization of the ihfA-1, ihfA-2, ihfB-1, and ihfB-2 from G. sulfurreducens. Unlike the ΔihfA-2 or ΔihfB-1 strains, single gene deletion in ihfA-1 or ihfB-2, provokes an impairment in fumarate and Fe(III) citrate reduction. Accordingly, sqRT-PCR experiments showed that ihfA-1 and ihfB-2 were expressed at higher levels than ihfA-2 and ihfB-1. In addition, RNA-Seq analysis of the ΔihfA-1 and ΔihfB-2 strains revealed a total of 89 and 122 differentially expressed genes, respectively. Furthermore, transcriptional changes in 25 genes were shared in both mutant strains. Among these genes, we confirmed the upregulation of the pilA-repressor, GSU1771, and downregulation of the triheme-cytochrome (pgcA) and the aconitate hydratase (acnA) genes by RT-qPCR. EMSA experiments also demonstrated the direct binding of IHF to the upstream promoter regions of GSU1771, pgcA and acnA. PilA changes in ΔihfA-1 and ΔihfB-2 strains were also verified by immunoblotting. Additionally, heme-staining of subcellular fractions in ΔihfA-1 and ΔihfB-2 strains revealed a remarkable deficit of c-type cytochromes. Overall, our data indicate that at least during fumarate and Fe(III) citrate reduction, the functional IHF regulator is likely assembled by the products of ihfA-1 and ihfB-2. Also, a role of IHF controlling expression of multiple genes (other than RpoN-dependent) affects G. sulfurreducens physiology and extracellular electron transfer.
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Geobacter sulfurreducens is capable of reducing Pd(II) to Pd(0) using acetate as electron donor; however, the biochemical and genetic mechanisms involved in this process have not been described. In this work, we carried out transcriptome profiling analysis to identify the genes involved in Pd(II) reduction in this bacterium. Our results showed that 252 genes were upregulated while 141 were downregulated during Pd(II) reduction. Among the upregulated genes, 12 were related to energy metabolism and electron transport, 50 were classified as involved in protein synthesis, 42 were associated to regulatory functions and transcription, and 47 have no homologs with known function. RT-qPCR data confirmed upregulation of genes encoding PilA, the structural protein for electrically conductive pili, as well as c-type cytochromes GSU1062, GSU2513, GSU2808, GSU2934, GSU3107, OmcH, OmcM, PpcA, and PpcD under Pd(II)-reducing conditions. ΔpilA and ΔpilR mutant strains showed 20% and 40% decrease in the Pd(II)-reducing capacity, respectively, as compared to the wild type strain, indicating the central role of pili in this process. RT-qPCR data collected during Pd(II) reduction also confirmed downregulation of omcB, omcC, omcZ, and omcS genes, which have been shown to be involved in the reduction of Fe(III) and electrodes. The present study contributes to elucidate the mechanisms involved in Pd(II) reduction by G. sulfurreducens. Graphical Abstract KEY POINTS: ⢠Transcriptome analysis provided evidence on Pd(II) reduction by G. sulfurreducens. ⢠Results indicate that electrically conductive pili is involved in Pd(II) reduction. ⢠G. sulfurreducens was not able to grow under Pd(II)-reducing conditions. ⢠The study contributes to a better understanding of the mechanisms in Pd(II) reduction.
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Citocromos/genética , Perfilación de la Expresión Génica , Geobacter/genética , Paladio/metabolismo , Citocromos/clasificación , Regulación hacia Abajo , Transporte de Electrón/genética , Metabolismo Energético/genética , Regulación Bacteriana de la Expresión Génica , Oxidación-Reducción , Regulación hacia ArribaRESUMEN
Bacteria play an important role in ecological processes in oil contaminated marine sediments. In this work, bacterial diversity studies with surface sediment samples from the NW Gulf of Mexico were performed, two from continental shelf and two from upper slope. The bacterial communities seem significantly influenced by depth, distance from the shoreline, temperature, dissolved oxygen and aluminum. The most abundant Phylum was Proteobacteria, Class Gammaproteobacteria. However, Class Deltaproteobacteria, Order Desulfuromonadales predominated in continental shelf and Order Alteromonadales (Gammaproteobacteria) prevailed in the upper slope sediments. Many potential hydrocarbon degrading bacterial genera were identified, 71 of the assigned genera were associated to hydrocarbon degradation processes. The genera Desulfobulbus and Haliea were confined to continental inner-shelf, while Shewanella and Fusibacter were mostly detected in deeper sediments. The occurrence and abundance of putative hydrocarbon degrading bacteria in this area, could be indicative of an impacted zone caused by the presence hydrocarbons in the environment.
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Bacterias/metabolismo , Sedimentos Geológicos/microbiología , Hidrocarburos/metabolismo , Biodegradación Ambiental , Biodiversidad , Gammaproteobacteria , Golfo de México , Microbiología del AguaRESUMEN
BACKGROUND: Upon exposure to unfavorable environmental conditions, plants need to respond quickly to maintain their homeostasis. For instance, physiological, biochemical and transcriptional changes occur during plant-pathogen interaction. In the case of Vanilla planifolia Jacks., a worldwide economically important crop, it is susceptible to Fusarium oxysporum f. sp. vanillae (Fov). This pathogen causes root and stem rot (RSR) in vanilla plants that lead to plant death. To investigate how vanilla plants, respond at the transcriptional level upon infection with Fov, here we employed the RNA-Seq approach to analyze the dynamics of whole-transcriptome changes during two-time frames of the infection. RESULTS: Analysis of global gene expression profiles upon infection by Fov indicated that the major transcriptional change occurred at 2 days post-inoculation (dpi), in comparison to 10 dpi. Briefly, the RNA-Seq analysis carried out in roots found that 3420 and 839 differentially expressed genes (DEGs) were detected at 2 and 10 dpi, respectively, as compared to the control. In the case of DEGs at 2 dpi, 1563 genes were found to be up-regulated, whereas 1857 genes were down-regulated. Moreover, functional categorization of DEGs at 2 dpi indicated that up-regulated genes are mainly associated to translation, whereas down-regulated genes are involved in cell wall remodeling. Among the translational-related transcripts, ribosomal proteins (RPs) were found increased their expression exclusively at 2 dpi. CONCLUSIONS: The screening of transcriptional changes of V. planifolia Jacks upon infection by Fov provides insights into the plant molecular response, particularly at early stages of infection. The accumulation of translational-related transcripts at early stages of infection potentially points to a transcriptional reprogramming coupled with a translational regulation in vanilla plants upon infection by Fov. Altogether, the results presented here highlight potential molecular players that might be further studied to improve Fov-induced resistance in vanilla plants.
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Fusarium/fisiología , Perfilación de la Expresión Génica , Enfermedades de las Plantas/microbiología , Biosíntesis de Proteínas , Vanilla/genética , Vanilla/microbiología , Anotación de Secuencia Molecular , Raíces de Plantas/microbiología , Proteínas Ribosómicas/genética , Vanilla/metabolismoRESUMEN
Babesiosis is considered an emerging disease because its incidence has significantly increased in the last 30 years, providing evidence of the expanding range of this rare but potentially life-threatening zoonotic disease. Babesia divergens is a causative agent of babesiosis in humans and cattle in Europe. The recently sequenced genome of B. divergens revealed over 3,741 protein coding-genes and the 10.7-Mb high-quality draft become the first reference tool to study the genome structure of B. divergens. Now, by exploiting this sequence data and using new computational tools and assembly strategies, we have significantly improved the quality of the B. divergens genome. The new assembly shows better continuity and has a higher correspondence to B. bovis chromosomes. Moreover, we present a differential expression analysis using RNA sequencing of the two different stages of the asexual lifecycle of B. divergens: the free merozoite capable of invading erythrocytes and the intraerythrocytic parasite stage that remains within the erythrocyte until egress. Comparison of mRNA levels of both stages identified 1,441 differentially expressed genes. From these, around half were upregulated and the other half downregulated in the intraerythrocytic stage. Orthogonal validation by real-time quantitative reverse transcription PCR confirmed the differential expression. A moderately increased expression level of genes, putatively involved in the invasion and egress processes, were revealed in the intraerythrocytic stage compared with the free merozoite. On the basis of these results and in the absence of molecular models of invasion and egress for B. divergens, we have proposed the identified genes as putative molecular players in the invasion and egress processes. Our results contribute to an understanding of key parasitic strategies and pathogenesis and could be a valuable genomic resource to exploit for the design of diagnostic methods, drugs and vaccines to improve the control of babesiosis.
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Babesia/crecimiento & desarrollo , Babesia/genética , Perfilación de la Expresión Génica , Genoma de Protozoos , Animales , Babesiosis/parasitología , Bovinos , Enfermedades de los Bovinos/parasitología , Biología Computacional , Genómica , HumanosRESUMEN
The current DNA sequencing technologies and their high-throughput yield, allowed the thrive of genomic and transcriptomic experiments but it also have generated big data problem. Due to this exponential growth of sequencing data, also the complexity of managing, processing and interpreting it in order to generate results, has raised. Therefore, the demand of easy-to-use friendly software and websites to run bioinformatic tools is imminent. In particular, RNA-Seq and differential expression analysis have become a popular and useful method to evaluate the genetic expression change in any organism. However, many scientists struggle with the data analysis since most of the available tools are implemented in a UNIX-based environment. Therefore, we have developed the web server IDEAMEX (Integrative Differential Expression Analysis for Multiple EXperiments). The IDEAMEX pipeline needs a raw count table for as many desired replicates and conditions, allowing the user to select which conditions will be compared, instead of doing all-vs.-all comparisons. The whole process consists of three main steps (1) Data Analysis: that allows a preliminary analysis for quality control based on the data distribution per sample, using different types of graphs; (2) Differential expression: performs the differential expression analysis with or without batch effect error awareness, using the bioconductor packages, NOISeq, limma-Voom, DESeq2 and edgeR, and generate reports for each method; (3) Result integration: the obtained results the integrated results are reported using different graphical outputs such as correlograms, heatmaps, Venn diagrams and text lists. Our server allows an easy and friendly visualization for results, providing an easy interaction during the analysis process, as well as error tracking and debugging by providing output log files. The server is currently available and can be accessed at http://www.uusmb.unam.mx/ideamex/ where the documentation and example input files are provided. We consider that this web server can help other researchers with no previous bioinformatic knowledge, to perform their analyses in a simple manner.
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El objetivo de este trabajo fue comparar ventajas potenciales de la radioterapia de intensidad modulada (IMRT) vs. la radioterapia 3D (3DRT) en el control loco-regional y la toxicidad aguda en pacientes con cáncer de recto localmente avanzado (CRLA). Se analizaron retrospectivamente 235 pacientes con adenocarcinoma de recto T2/T4 y N0/N1 sometidos a radioquimioterapia neoadyuvante entre febrero de 2010 y agosto de 2015. La modalidad radiante se correlacionó con los resultados clínicos (control local y a distancia) y las tasas de toxicidades agudas urinarias, hematológicas, gastrointestinales (GI) y dérmicas. Ciento cuarenta (59.6%) recibieron IMRT y 95 (40.4%) 3DRT. La mediana de seguimiento fue de 36 meses. Las tasas de recidiva local y metástasis a distancia fueron similares entre IMRT y 3DRT. No se encontraron diferencias estadísticamente significativas en control local (CL) ni en supervivencia global (SG) entre IMRT y 3DRT (p=0.56 y p=0.24, respectivamente), ni en colostomía libre para tumores rectales bajos (p=0.44). IMRT implicó menor toxicidad cutánea (p<0.001), hematológica (p<0.0001), urinaria (p=0.0017), y gastrointestinal (p=0.0006). La incidencia de diarrea grado ≥ 3 fue del 16% entre los pacientes del grupo 3DRT frente al 5% de del grupo IMRT. En el análisis univariado, el estadio clínico T, edad, KPS, y quimioterapia adyuvante se asociaron con mejor SG (todos p<0.05) y la dosis total de radiación se asoció con mejor período libre de enfermedad (p=0.0065) Postulamos que IMRT permitiría un aumento de dosis en forma segura con el potencial de aumentar la tasa de respuestas patológicas completas (RPC), en particular en tumores rectales bajos (AU)
The aim was to compare the advantages of IMRT vs. 3D in loco regional control and acute toxicity in patients with locally advanced rectum cancer. We analyzed retrospectively 235 patients with rectal adenocarcinoma T2/T4 and N0/N1 undergoing chemo radiation between February 2010 and August 2015. The radiant modality was correlated with clinical outcomes (local and systemic control) and rates of acute urinary, hematological, gastrointestinal and dermal toxicities. One hundred and forty patients (59.6%) received IMRT and 95 (40.4%) received 3D. The median follow-up time was 36 months. The rates of local recurrence and distant metastases were similar between IMRT vs. 3D. No statistically significant differences were found in local control or survival between IMRT and 3D (p=0.56 and p =0.24, respectively), nor in free colostomy for low rectal tumors (p= 0.44). IMRT resulted in lower dermal (p<0.001), hematological (p<0.0001), urinary (p=0.0017), and gastrointestinal toxicity (p=0.0006). The incidence of diarrhea grade ≥ 3 was 16% among 3D patients vs. 5% in IMRT. In the univariate analysis, clinical stage T, age, KPS, and adjuvant chemotherapy were associated with better overall survival (all p<0.05) and the total dose of radiation was associated with better disease-free period (p=0.0065). We postulate that IMRT would allow us to increase dose in a safe manner with the potential to increase rate of complete pathological responses, particularly in low rectal tumors (AU)
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Humanos , Masculino , Femenino , Persona de Mediana Edad , Radioterapia Conformacional , Radioterapia de Intensidad Modulada , Neoplasias del Recto/radioterapia , Terapia NeoadyuvanteRESUMEN
Las técnicas definitivas de quimio-radioterapia para el cáncer anal, radioterapia tridimensional conformada (3DCRT) o radioterapia de intensidad modulada (IMRT) dan excelentes resultados a largo plazo. Evaluamos resultados en centros de radiación basados en la comunidad. Se evaluaron retrospectivamente 281 pacientes tratados con quimio-radioterapia definitiva para carcinoma anal loco-regional, entre 2006 y 2014. El 95% realizó quimioterapia. Se evaluaron datos de toxicidades, progresión de la enfermedad y necesidad de colostomía durante el período de seguimiento. La supervivencia global, supervivencia libre de progresión y colostomía libre se calcularon con métodos de Kaplan-Meier. La edad media fue 63.7 años con seguimiento medio de 60 meses. Ciento sesenta y nueve pacientes recibieron IMRT y 112 recibieron 3DCRT. La dosis total media tumoral fue 54 Gy. El 80% experimentó complicaciones agudas, y el 56% requirió interrupción de tratamiento. No hubo diferencias significativas en supervivencia global, supervivencia libre de progresión, supervivencia libre de colostomía ni control local a dos años entre ambos grupos. La IMRT tuvo menos suspensión del tratamiento (48% vs. 65%) (p=0.0261). El grupo IMRT tuvo una reducción significativa de todas las toxicidades agudas ≥3 y gastrointestinales (GI) tardías, en comparación con los tratados con 3DCRT. Esta serie representa una de las mayores comparaciones 3DCRT vs. IMRT para el tratamiento definitivo de cáncer anal. Los resultados a largo plazo no difieren significativamente en función de la técnica de radioterapia (RT). La IMRT reduce todas las toxicidades ≥ grado 3 y la necesidad de interrupción en comparación con 3DCRT (AU)
The definitive techniques of chemo-radiotherapy for anal cancer, 3DCRT or IMRT, give excellent long-term results. We evaluated results in community-based radiation centers. We retrospectively evaluated 281 patients treated with definitive chemo-radiotherapy for locoregional anal carcinoma, between 2006 and 2014. The 95% performed chemotherapy. Toxicity data, progression of the disease, need of colostomy during the follow-up period were evaluated. Global survival (GS), progression free survival (PFS), and free colostomy survival (CFS) were calculated with Kaplan-Meier methods. Mean age was 63.7 years with a mean follow-up of 60 months. One hundred and sixty nine patients received IMRT and 112 received 3DCRT. The total mean tumor dose was 54 Gy. The 80% experienced acute complications, and 56% required treatment interruption. There was no significant difference in GS, PFS, CFS or local control at two years between both groups. The IMRT had less treatment discontinuation (48% vs. 65%) (p = 0.0261). The IMRT group had a significant reduction in all acute toxicities ≥3 and late gastrointestinal, compared with those treated with 3DCRT. This series represents one of the largest 3DCRT vs. IMRT comparisons for the definitive treatment of anal cancer. The long-term results do not differ significantly depending on the RT technique. The IMRT reduces all toxicities ≥ grade 3 and the need for interruption compared to 3DCRT (AU)
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Humanos , Neoplasias del Ano/radioterapia , Radioterapia Conformacional , Radioterapia de Intensidad Modulada , Estudios Retrospectivos , ToxicidadRESUMEN
Wetlands constitute the main natural source of methane on Earth due to their high content of natural organic matter (NOM), but key drivers, such as electron acceptors, supporting methanotrophic activities in these habitats are poorly understood. We performed anoxic incubations using freshly collected sediment, along with water samples harvested from a tropical wetland, amended with 13C-methane (0.67 atm) to test the capacity of its microbial community to perform anaerobic oxidation of methane (AOM) linked to the reduction of the humic fraction of its NOM. Collected evidence demonstrates that electron-accepting functional groups (e.g., quinones) present in NOM fueled AOM by serving as a terminal electron acceptor. Indeed, while sulfate reduction was the predominant process, accounting for up to 42.5% of the AOM activities, the microbial reduction of NOM concomitantly occurred. Furthermore, enrichment of wetland sediment with external NOM provided a complementary electron-accepting capacity, of which reduction accounted for â¼100 nmol 13CH4 oxidized · cm-3 · day-1 Spectroscopic evidence showed that quinone moieties were heterogeneously distributed in the wetland sediment, and their reduction occurred during the course of AOM. Moreover, an enrichment derived from wetland sediments performing AOM linked to NOM reduction stoichiometrically oxidized methane coupled to the reduction of the humic analogue anthraquinone-2,6-disulfonate. Microbial populations potentially involved in AOM coupled to microbial reduction of NOM were dominated by divergent biota from putative AOM-associated archaea. We estimate that this microbial process potentially contributes to the suppression of up to 114 teragrams (Tg) of CH4 · year-1 in coastal wetlands and more than 1,300 Tg · year-1, considering the global wetland area.IMPORTANCE The identification of key processes governing methane emissions from natural systems is of major importance considering the global warming effects triggered by this greenhouse gas. Anaerobic oxidation of methane (AOM) coupled to the microbial reduction of distinct electron acceptors plays a pivotal role in mitigating methane emissions from ecosystems. Given their high organic content, wetlands constitute the largest natural source of atmospheric methane. Nevertheless, processes controlling methane emissions in these environments are poorly understood. Here, we provide tracer analysis with 13CH4 and spectroscopic evidence revealing that AOM linked to the microbial reduction of redox functional groups in natural organic matter (NOM) prevails in a tropical wetland. We suggest that microbial reduction of NOM may largely contribute to the suppression of methane emissions from tropical wetlands. This is a novel avenue within the carbon cycle in which slowly decaying NOM (e.g., humic fraction) in organotrophic environments fuels AOM by serving as a terminal electron acceptor.
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Bacterias/metabolismo , Metano/metabolismo , Anaerobiosis , Antraquinonas/metabolismo , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Oxidación-Reducción , HumedalesRESUMEN
Geobacter sulfurreducens is an anaerobic soil bacterium that is involved in biogeochemical cycles of elements such as Fe and Mn. Although significant progress has been made in the understanding of the electron transfer processes in G. sulfurreducens, little is known about the regulatory mechanisms involved in their control. To expand the study of gene regulation in G. sulfurreducens, we carried out a genome-wide identification of transcription start sites (TSS) by 5'RACE and by deep RNA sequencing of primary mRNAs in two growth conditions. TSSs were identified along G. sulfurreducens genome and over 50% of them were located in the upstream region of the associated gene, and in some cases we detected genes with more than one TSS. Our global mapping of TSSs contributes with valuable information, which is needed for the study of transcript structure and transcription regulation signals and can ultimately contribute to the understanding of transcription initiation phenomena in G. sulfurreducens.
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Regulación Bacteriana de la Expresión Génica , Geobacter/genética , Sitio de Iniciación de la Transcripción , Proteínas Bacterianas/genética , Transporte de Electrón , Electrones , Perfilación de la Expresión Génica , Genoma Bacteriano , Geobacter/crecimiento & desarrollo , Regiones Promotoras Genéticas , Análisis de Secuencia de ARN , Transcripción GenéticaRESUMEN
Torulaspora delbrueckii presents metabolic features interesting for biotechnological applications (in the dairy and wine industries). Recently, the T. delbrueckii CBS 1146 genome, which has been maintained under laboratory conditions since 1970, was published. Thus, a genome of a new mezcal yeast was sequenced and characterized and showed genetic differences and a higher genome assembly quality, offering a better reference genome.
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Candida apicola, a highly osmotolerant ascomycetes yeast, produces sophorolipids (biosurfactants), membrane fatty acids, and enzymes of biotechnological interest. The genome obtained has a high-quality draft for this species and can be used as a reference to perform further analyses, such as differential gene expression in yeast from Candida genera.
RESUMEN
Hypoglycemia is a serious complication of insulin therapy in patients suffering from type 1 Diabetes Mellitus. Severe hypoglycemia leading to coma (isoelectricity) induces massive neuronal death in vulnerable brain regions such as the hippocampus, the striatum and the cerebral cortex. It has been suggested that the production of reactive oxygen species (ROS) and oxidative stress is involved in hypoglycemic brain damage, and that ROS generation is stimulated by glucose reintroduction (GR) after the hypoglycemic coma. However, the distribution of ROS in discrete brain regions has not been studied in detail. Using the oxidation sensitive marker dihydroethidium (DHE) we have investigated the distribution of ROS in different regions of the mouse brain during prolonged severe hypoglycemia without isoelectricity, as well as the effect of GR on ROS levels. Results show that ROS generation increases in the hippocampus, the cerebral cortex and the striatum after prolonged severe hypoglycemia before the coma. The hippocampus showed the largest increases in ROS levels. GR further stimulated ROS production in the hippocampus and the striatum while in the cerebral cortex, only the somatosensory and parietal areas were significantly affected by GR. Results suggest that ROS are differentially produced during the hypoglycemic insult and that a different response to GR is present among distinct brain regions.