RESUMO
Investigations into traffic accidents that lead to the determination of their causes and consequences are useful to all interested parties, both in the public and private sectors. One of the phases of investigation is the capture of data enabling the complete reconstruction of the accident scene, which is usually the point at which a conflict arises between the slow process of information gathering and the need to restore normal traffic flow. To reduce to a minimum the time the traffic is halted, this paper follows a methodology to reconstruct traffic accidents and puts forward a series of procedures and tools that are applicable to both large and small scenarios. The methodology uses low-cost UAV-SfM in combination with UAS aerial image capture systems and inexpensive GNSS equipment costing less than 900. This paper describes numerous tests and assessments that were carried out on four potential work scenarios (E-1 and E-2 urban roads with several intersections; E-3, an urban crossing with medium slopes; and E-4, a complex road section with different land morphologies), assessing the impact of using simple or double strip flights and the number of GCPs, their spacing distance and different distribution patterns. From the different configurations tested, the best results were achieved in those offset-type distributions where the GCPs were placed on both sides of the working area and at each end, with a spacing between 100 and 50 m and using double strip flights. Our conclusion is that the application of this protocol would be highly efficient and economical in the reconstruction of traffic accidents, provide simplicity in implementation, speed of capture and data processing, and provide reliable results quite economically and with a high degree of accuracy with RMSE values below 5 cm.
RESUMO
Antiviral DNA cytosine deaminases APOBEC3A and APOBEC3B are major sources of mutations in cancer by catalyzing cytosine-to-uracil deamination. APOBEC3A preferentially targets single-stranded DNAs, with a noted affinity for DNA regions that adopt stem-loop secondary structures. However, the detailed substrate preferences of APOBEC3A and APOBEC3B have not been fully established, and the specific influence of the DNA sequence on APOBEC3A and APOBEC3B deaminase activity remains to be investigated. Here, we find that APOBEC3B also selectively targets DNA stem-loop structures, and they are distinct from those subjected to deamination by APOBEC3A. We develop Oligo-seq, an in vitro sequencing-based method to identify specific sequence contexts promoting APOBEC3A and APOBEC3B activity. Through this approach, we demonstrate that APOBEC3A and APOBEC3B deaminase activity is strongly regulated by specific sequences surrounding the targeted cytosine. Moreover, we identify the structural features of APOBEC3B and APOBEC3A responsible for their substrate preferences. Importantly, we determine that APOBEC3B-induced mutations in hairpin-forming sequences within tumor genomes differ from the DNA stem-loop sequences mutated by APOBEC3A. Together, our study provides evidence that APOBEC3A and APOBEC3B can generate distinct mutation landscapes in cancer genomes, driven by their unique substrate selectivity.
Assuntos
Neoplasias , Proteínas , Humanos , Mutação , Neoplasias/genética , Citidina Desaminase/genética , Citidina Desaminase/química , DNA , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/química , CitosinaRESUMO
Introduction: Takotsubo syndrome (TTS) encompasses distinct variants, with midventricular (MV) as the most common atypical subtype. While electrocardiogram (ECG) abnormalities are well documented in typical TTS, they are less explored in MV-TTS. Methods: A retrospective case-control study was conducted where ECGs were reviewed at three time points from symptom onset (within the first 12 h, at 48 h, and at 5-7 days) and compared between patients with typical TTS (n = 33) and those with MV-TTS (n = 27), as classified by ventriculography. Results: 12-h ECG findings revealed that typical TTS featured ST-segment elevation through anterior leads V3-V6, with maximal deviation in V3 (0.98 ± 0.99â mm) and V4 (0.91 ± 0.91â mm), whereas MV-TTS featured ST-segment depression in inferior leads (-0.24 ± 0.57â mm in II, -0.30 ± 0.52â mm in III, and -0.32 ± 0.47â mm in aVF) and in precordial leads V4-V6. In 48-h ECG findings, the most significant change was T wave inversion, which was more widespread and deeper in typical TTS, with the most pronounced negative T wave depths, exceeding 3â mm, observed in leads V3-V5; in contrast, in MV-TTS, T wave inversion was evident in fewer leads and showed less depth, with the most pronounced negative T waves reaching 1â mm at most in leads I, aVL, and V2. While the QTc interval was prolonged in both groups at 48â h, this prolongation was more pronounced in typical TTS than in MV-TTS (523 ± 52â ms vs. 487 ± 66â ms; p = 0.029). In ECGs at 5-7 days, results essentially returned to baseline. Conclusion: Patients with MV-TTS exhibited a distinctive pattern of ECG abnormalities, marked by ST-segment depression in inferolateral leads, less profound and less extensive T wave inversion that mostly affected leads I, aVL and V2, and attenuated QT interval prolongation compared to typical TTS.
RESUMO
Chronic infections and cancers evade the host immune system through mechanisms that induce T cell exhaustion. The heterogeneity within the exhausted CD8+ T cell pool has revealed the importance of stem-like progenitor (Tpex) and terminal (Tex) exhausted T cells, although the mechanisms underlying their development are not fully known. Here we report High Mobility Group Box 2 (HMGB2) protein expression is upregulated and sustained in exhausted CD8+ T cells, and HMGB2 expression is critical for their differentiation. Through epigenetic and transcriptional programming, we identify HMGB2 as a cell-intrinsic regulator of the differentiation and maintenance of Tpex cells during chronic viral infection and in tumors. Despite Hmgb2-/- CD8+ T cells expressing TCF-1 and TOX, these master regulators were unable to sustain Tpex differentiation and long-term survival during persistent antigen. Furthermore, HMGB2 also had a cell-intrinsic function in the differentiation and function of memory CD8+ T cells after acute viral infection. Our findings show that HMGB2 is a key regulator of CD8+ T cells and may be an important molecular target for future T cell-based immunotherapies.
Assuntos
Neoplasias , Viroses , Humanos , Linfócitos T CD8-Positivos , Proteína HMGB2/genética , Infecção Persistente , Diferenciação CelularRESUMO
BACKGROUND: Upper limb apraxia (ULA) is a neurological syndrome characterized by the inability to perform purposeful movements. ULA could impact individuals' perceptions, including perceived self-efficacy. The aim of this study is to investigate whether ULA is related to general self-efficacy and self-efficacy for managing symptoms in post-stroke patients. METHODS: A cross-sectional study was conducted involving 82 post-stroke patients. Regression analyses were implemented using a stepwise model including seven dimensions of ULA: imitation (non-symbolic, intransitive, and transitive), pantomime (non-symbolic, intransitive, and transitive), and dimension of apraxic performance in activities of daily living. These dimensions were independent variables, while general self-efficacy and symptom management self-efficacy dimensions were dependent variables. RESULTS: The findings revealed that intransitive imitation accounted for 14% of the variance in general self-efficacy and 10% of self-efficacy for managing emotional symptoms. Transitive imitation explained 10% of the variance in self-efficacy for managing global symptoms and 5% for social-home integration symptoms. The combination of intransitive imitation, non-symbolic pantomime, and alterations in activities of daily living performance associated with ULA explained 24% of the variance in cognitive self-efficacy. CONCLUSIONS: Hence, ULA dimensions seem to be related to the levels of general perceived self-efficacy and self-efficacy for managing symptoms among post-stroke patients.
RESUMO
Antiviral DNA cytosine deaminases APOBEC3A and APOBEC3B are major sources of mutations in cancer by catalyzing cytosine-to-uracil deamination. APOBEC3A preferentially targets singlestranded DNAs, with a noted affinity for DNA regions that adopt stem-loop secondary structures. However, the detailed substrate preferences of APOBEC3A and APOBEC3B have been fully established, and the specific influence of the DNA sequence on APOBEC3A APOBEC3B deaminase activity remains to be investigated. Here, we find that APOBEC3B selectively targets DNA stem-loop structures, and they are distinct from those subjected deamination by APOBEC3A. We develop Oligo-seq, a novel in vitro sequencing-based to identify specific sequence contexts promoting APOBEC3A and APOBEC3B activity. Through this approach, we demonstrate that APOBEC3A an APOBEC3B deaminase activity is strongly regulated by specific sequences surrounding the targeted cytosine. Moreover, we identify structural features of APOBEC3B and APOBEC3A responsible for their substrate preferences. Importantly, we determine that APOBEC3B-induced mutations in hairpin-forming sequences within tumor genomes differ from the DNA stem-loop sequences mutated by APOBEC3A. Together, our study provides evidence that APOBEC3A and APOBEC3B can generate mutation landscapes in cancer genomes, driven by their unique substrate selectivity.
RESUMO
Double-stranded RNA produced during viral replication and transcription activates both protein kinase R (PKR) and ribonuclease L (RNase L), which limits viral gene expression and replication through host shutoff of translation. In this study, we find that APOBEC3B forms a complex with PABPC1 to stimulate PKR and counterbalances the PKR-suppressing activity of ADAR1 in response to infection by many types of viruses. This leads to translational blockage and the formation of stress granules. Furthermore, we show that APOBEC3B localizes to stress granules through the interaction with PABPC1. APOBEC3B facilitates the formation of protein-RNA condensates with stress granule assembly factor (G3BP1) by protecting mRNA associated with stress granules from RNAse L-induced RNA cleavage during viral infection. These results not only reveal that APOBEC3B is a key regulator of different steps of the innate immune response throughout viral infection but also highlight an alternative mechanism by which APOBEC3B can impact virus replication without editing viral genomes.
Assuntos
Grânulos de Estresse , Viroses , Humanos , DNA Helicases/metabolismo , RNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Replicação Viral , Proteínas Quinases/metabolismo , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo , Grânulos Citoplasmáticos/metabolismo , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismoRESUMO
A 15-year-old boy was admitted to the hospital due to ataxia, drowsiness and bradypsychia. He was known to have a short bowel syndrome Initial venous blood gases revealed a metabolic acidosis with a high anion gap of 24 mmol/L and normal L-lactate. He improved with fasting and fluids and was discharged with oral metronidazole. 2 weeks later he was admitted again with similar symptoms. A specific study of D-Lactic acidosis was carried out, confirming the diagnosis. D-lactic acidosis is an uncommon complication of short bowel syndrome. It occurs as a consequence of the metabolism of unabsorbed carbohydrates. The symptoms are mainly neurological. Limiting the dietary carbohydrates is useful to avoid recurrences. Poorly absorbable antibiotics are used but with varying results. Surgery may be an option if medical treatment fails. Probiotics might be useful to avoid symthoms recurrence.
Assuntos
Acidose Láctica , Encefalopatias , Síndrome do Intestino Curto , Masculino , Humanos , Adolescente , Acidose Láctica/complicações , Acidose Láctica/diagnóstico , Síndrome do Intestino Curto/complicações , Síndrome do Intestino Curto/terapia , Encefalopatias/complicações , Encefalopatias/tratamento farmacológico , Antibacterianos/uso terapêutico , Carboidratos da DietaRESUMO
The repair of DNA double-strand breaks is crucial for cell viability and the maintenance of genome integrity. When present, the intact sister chromatid is used as the preferred repair template to restore the genetic information by homologous recombination. Although the study of the factors involved in sister chromatid recombination is hampered by the fact that both sister chromatids are indistinguishable, genetic and molecular systems based on DNA repeats have been developed to overcome this problem. In particular, the use of site-specific nucleases capable of inducing DNA nicks that replication converts into double-strand breaks has enabled the specific study of the repair of such replication-born double strand breaks by sister chromatid recombination. In this chapter, we describe detailed protocols for determining the efficiency and kinetics of this recombination reaction as well as for the genetic quantification of recombination products.
Assuntos
Cromátides , Saccharomyces cerevisiae , Cromátides/genética , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Saccharomyces cerevisiae/genética , Troca de Cromátide IrmãRESUMO
The replication of chromosomes during S phase is critical for cellular and organismal function. Replicative stress can result in genome instability, which is a major driver of cancer. Yet how chromatin is made accessible during eukaryotic DNA synthesis is poorly understood. Here, we report the characterization of a chromatin remodeling enzyme-Yta7-entirely distinct from classical SNF2-ATPase family remodelers. Yta7 is a AAA+ -ATPase that assembles into ~1 MDa hexameric complexes capable of segregating histones from DNA. The Yta7 chromatin segregase promotes chromosome replication both in vivo and in vitro. Biochemical reconstitution experiments using purified proteins revealed that the enzymatic activity of Yta7 is regulated by S phase-forms of Cyclin-Dependent Kinase (S-CDK). S-CDK phosphorylation stimulates ATP hydrolysis by Yta7, promoting nucleosome disassembly and chromatin replication. Our results present a mechanism for how cells orchestrate chromatin dynamics in co-ordination with the cell cycle machinery to promote genome duplication during S phase.
Assuntos
Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Replicação do DNA/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Adenosina Trifosfatases/metabolismo , Pontos de Checagem do Ciclo Celular , Montagem e Desmontagem da Cromatina , Proteínas Cromossômicas não Histona/genética , DNA/metabolismo , Histonas/metabolismo , Humanos , Fosforilação , Fase S , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Fatores de TranscriçãoRESUMO
It has been long known that some regions of the genome are more susceptible to damage and mutagenicity than others. Recent advances have determined a critical role of chromatin both in the incidence of damage and in its repair. Thus, chromatin arises as a guardian of the stability of the genome, which is altered in cancer cells. In this review, we focus into the mechanisms by which chromatin influences the occurrence and repair of the most cytotoxic DNA lesions, double-strand breaks, in particular at actively transcribed chromatin or related to DNA replication.
Assuntos
CromatinaRESUMO
DNA double-strand breaks (DSBs) are the most harmful DNA lesions and their repair is crucial for cell viability and genome integrity. The readout of DSB repair may depend on whether DSBs occur at transcribed versus non-transcribed regions. Some studies have postulated that DNA-RNA hybrids form at DSBs to promote recombinational repair, but others have challenged this notion. To directly assess whether hybrids formed at DSBs promote or interfere with the recombinational repair, we have used plasmid and chromosomal-based systems for the analysis of DSB-induced recombination in Saccharomyces cerevisiae. We show that, as expected, DNA-RNA hybrid formation is stimulated at DSBs. In addition, mutations that promote DNA-RNA hybrid accumulation, such as hpr1∆ and rnh1∆ rnh201∆, cause high levels of plasmid loss when DNA breaks are induced at sites that are transcribed. Importantly, we show that high levels or unresolved DNA-RNA hybrids at the breaks interfere with their repair by homologous recombination. This interference is observed for both plasmid and chromosomal recombination and is independent of whether the DSB is generated by endonucleolytic cleavage or by DNA replication. These data support a model in which DNA-RNA hybrids form fortuitously at DNA breaks during transcription and need to be removed to allow recombinational repair, rather than playing a positive role.
Assuntos
Quebras de DNA de Cadeia Dupla , DNA , RNA , Reparo de DNA por Recombinação , 3-Isopropilmalato Desidrogenase/genética , 3-Isopropilmalato Desidrogenase/metabolismo , Reparo do DNA , Replicação do DNA , Regulação Fúngica da Expressão Gênica , Hibridização de Ácido Nucleico , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
Chickpea (Cicer aretinium L.) is a legume crop of great importance worldwide. In January 2019, wilting symptoms on chickpea (stunted grow, withered leaves, root rot and wilted plants) were observed in three fields of Culiacan Sinaloa Mexico, with an incidence of 3 to 5%. To identify the cause, eighty symptomatic chickpea plants were sampled. Tissue from roots was plated on potato dextrose agar (PDA) medium. Typical Fusarium spp. colonies were obtained from all root samples. Ten pure cultures were obtained by single-spore culturing (Ff01 to Ff10). On PDA the colonies were abundant with white aerial mycelium, hyphae were branched and septae and light purple pigmentation was observed in the center of old cultures (Leslie and Summerell 2006). From 10-day-old cultures grown on carnation leaf agar medium, macroconidias were falciform, hyaline, with slightly curved apexes, three to five septate, with well-developed foot cells and blunt apical cells, and measured 26.6 to 45.8 × 2.2 to 7.0 µm (n = 40). The microconidia (n = 40) were hyaline, one to two celled, produced in false heads that measured 7.4 to 20.1 (average 13.7) µm × 2.4 to 8.9 (average 5.3) µm (n = 40) at the tips of long monophialides, and were oval or reniform, with apexes rounded, 8.3 to 12.1 × 1.6 to 4.7 µm; chlamydospores were not evident. These characteristics fit those of the Fusarium solani (Mart.) Sacc. species complex, FSSC (Summerell et al. 2003). The internal transcribed spacer and the translation elongation factor 1 alpha (EF1-α) genes (O'Donnell et al. 1998) were amplified by polymerase chain reaction and sequenced from the isolate Ff02 and Ff08 (GenBank accession nos. KJ501093 and MN082369). Maximum likelihood analysis was carried out using the EF1-α sequences (KJ501093 and MN082369) from the Ff02 and Ff08 isolates and other species from the Fusarium solani species complex (FSSC). Phylogenetic analysis revealed the isolate most closely related with F. falciforme (100% bootstrap). For pathogenicity testing, a conidial suspension (1x106 conidia/ml) was prepared by harvesting spores from 10-days-old cultures on PDA. Twenty 2-week-old chickpea seedlings from two cultivars (P-2245 and WR-315) were inoculated by dipping roots into the conidial suspension for 20 min. The inoculated plants were transplanted into a 50-hole plastic tray containing sterilized soil and maintained in a growth chamber at 25°C, with a relative humidity of >80% and a 12-h/12-h light/dark cycle. After 8 days, the first root rot symptoms were observed on inoculating seedlings and the infected plants eventually died within 3 to 4 weeks after inoculation. No symptoms were observed plants inoculated with sterilized distilled water. The fungus was reisolated from symptomatic tissues of inoculated plants and was identified by sequencing the partial EF1-α gene again and was identified as F. falciforme (FSSC 3 + 4) (O'Donnell et al. 2008) based on its morphological characteristics, genetic analysis, and pathogenicity test, fulfilling Koch's postulates. The molecular identification was confirmed via BLAST on the FusariumID and Fusarium MLST databases. Although FSSC has been previously reported causing root rot in chickpea in USA, Chile, Spain, Cuba, Iran, Poland, Israel, Pakistan and Brazil, to our knowledge this is the first report of root rot in chickpea caused by F. falciforme in Mexico. This is important for chickpea producers and chickpea breeding programs.
Assuntos
COVID-19 , Miocardite , Vacinas , Vacina BNT162 , Vacinas contra COVID-19 , Humanos , Miocardite/induzido quimicamente , Miocardite/diagnóstico , SARS-CoV-2RESUMO
The stability and function of eukaryotic genomes is closely linked to histones and to chromatin structure. The state of the chromatin not only affects the probability of DNA to undergo damage but also DNA repair. DNA damage can result in genetic alterations and subsequent development of cancer and other genetic diseases. Here, we identified two mutations in conserved residues of histone H3 and histone H4 (H3E73Q and H4E53A) that increase recombinogenic DNA damage. Our results suggest that the accumulation of DNA damage in these histone mutants is largely independent on transcription and might arise as a consequence of problems occurring during DNA replication. This study uncovers the relevance of H3E73 and H4E53 residues in the protection of genome integrity.
RESUMO
El brote epidémico causado por el virus SARS-CoV-2 se encuentra plenamente activo en España. Alrededor del 10-15 % de los pacientes ingresados precisan cuidados en unidades de críticos, siendo intubados de forma prolongada y precisando la realización de traqueotomías. Se realiza un estudio observacional de las traqueotomías realizadas por nuestro Servicio de Cirugía Oral y Maxilofacial a pacientes COVID-19 de unidades de cuidados intensivos realizadas entre el 17 de marzo y el 17 de abril de 2020. El estudio analiza aspectos epidemiológicos y clínicos de los pacientes, el tipo de técnica quirúrgica empleada, el tiempo quirúrgico, el tipo de cánula empleada, las complicaciones postquirúrgicas y el seguimiento clínico de los pacientes. Un total de 22 pacientes fueron sometidos a traquetomía reglada abierta. Fueron dieciocho hombres y cuatro mujeres de edades entre 40 y 77 años (64,9 años de media). En todos los casos la realización de traqueotomía fue como consecuencia del proceso pulmonar por la neumonia bilateral COVID-19. Dos pacientes presentaron un neumotórax en el postoperatorio inmediato como complicación, un paciente falleció durante la realización del procedimiento y otro tras su llegada a la Unidad de Cuidados Intensivos tras la realización de la traqueotomía. A pesar de que la traqueotomía es una técnica quirúrgica reglada, las características especiales de los pacientes COVID-19 hacen de este procedimiento una situación crítica por la inestabilidad pulmonar y la rápida desaturación del paciente. Todo ello obliga a la realización del procedimiento por facultativos con experiencia para disminuir el tiempo quirúrgico y poder enfrentarse a cualquier eventualidad
The outbreak caused by the SARS-CoV-2 virus is currently very active in Spain. Many infected people still require to be hospitalized. Around 10-15 % of hospitalized patients require intensive care, where they are intubated for a prolonged period, needing tracheotomies some weeks after the intubation. We will be conducting an observational study of the tracheotomies performed by our oral and maxillofacial Department to COVID-19 patients on intensive care units between March 17th and April 17th, 2020. This study will be analyzing the patients' epidemiological and clinical aspects, surgical technique employed, surgical time, type of cannula used, postoperative complications and the patients' clinical monitoring. A total of 22 patients underwent open elective tracheotomy. There were twenty-two males and three females aged between 40 and 77 (mean: 64,9 years-old). In all cases tracheotomy was carried out due to pulmonary process caused by COVID-19 bilateral pneumonia. Two patients presented pneumothorax in the immediate postoperatory care as a complication, one perished during the procedure and another did so after arriving to the Intensive Care Unit after the tracheotomy surgery. Even though tracheotomy is a ruled surgical technique, the special characteristics of COVID-19 patients make of this procedure a critical situation, mainly due to lung instability and quick desaturation of the patients. This requires the surgery to be carried out by experienced physicians in order to reduce operative time and to be able to react to any eventualities that may arise
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Infecções por Coronavirus/cirurgia , Pneumonia Viral/cirurgia , Betacoronavirus , Pandemias , Traqueostomia/instrumentação , Traqueostomia/métodos , Hospitais Universitários , Seguimentos , Estado Terminal , Fatores de Tempo , EspanhaRESUMO
We have recently uncovered that loss of the yeast histone deacetylases Rpd3 (Reduced Potassium Dependency 3) and Hda1 (Histone DeAcetylase 3) affects the cohesion between sister chromatids thus impairing repair of DNA damage at replication forks and enhancing genetic instability. Here we discuss the possible implications of our findings given that histone deacetylases are a promising chemotherapeutic target often used in combination with DNA damaging agents.
RESUMO
Metabolic alkalosis is uncommon in infancy. Cystic fibrosis (CF) patients can develop dehydration because of sweat salt or gastrointestinal losses; with the correct salt supplementation, the electrolyte alterations can be reversed. Here, we present a CF patient with recurrent metabolic alkalosis, initially oriented as pseudo-Bartter's syndrome. However, despite accurate treatment, patient needed daily intravenous fluids to maintain homeostasis. An extended study was made, including a urine study that could rule out Bartter's diagnosis. Finally, after a complementary test that included electrolyte stools study and genetic analysis, congenital chloride diarrhea could be diagnosed.