Delayed mechanical ventilation with prolonged high-flow nasal cannula exposure time as a risk factor for mortality in acute respiratory distress syndrome due to SARS-CoV-2.

In a high proportion of patients, infection by COVID-19 progresses to acute respiratory distress syndrome (ARDS), requiring invasive mechanical ventilation (IMV) and admission to an intensive care unit (ICU). Other devices, such as a high-flow nasal cannula (HFNC), have been alternatives to IMV in settings with limited resources. This study evaluates whether HFNC exposure time prior to IMV is associated with mortality. This observational, analytical study was conducted on a historical cohort of adults with ARDS due to SARS-CoV-2 who were exposed to HFNC and subsequently underwent IMV. Univariate and multivariate logistic regression was used to analyze the impact of HFNC exposure time on mortality, controlling for multiple potential confounders. Of 325 patients with ARDS, 41 received treatment with HFNC for more than 48 h before IMV initiation. These patients had a higher mortality rate (43.9% vs. 27.1%, p: 0.027) than those using HFNC < 48 h. Univariate analysis evidenced an association between mortality and HFNC ≥ 48 h (OR 2.16. 95% CI 1.087-4.287. p: 0.028). Such an association persisted in the multivariable analysis (OR 2.21. 95% CI 1.013-4.808. p: 0.046) after controlling for age, sex, comorbidities, basal severity of infection, and complications. This study also identified a significant increase in mortality after 36 h in HFNC (46.3%, p: 0.003). In patients with ARDS due to COVID-19, HFNC exposure ≥ 48 h prior to IMV is a factor associated with mortality after controlling multiple confounders. Physiological mechanisms for such an association are need to be defined.

Curtobacterium, A Foliar Pathogen Isolated from Maize in Central Argentina.

Plant pathogens, such as fungi, bacteria, and viruses, can cause serious damage to crops and significantly reduce yield and quality. Bacterial diseases of agronomic crops, however, have been little studied. The present study aims to isolate and identify bacteria recovered from symptomatic maize (Zea mays) leaves collected from field samples in the province of Cordoba, Argentina. Bacterial strains were identified using whole-cell matrix-assisted laser-desorption-ionization-time-off light mass spectrometry and 16S rDNA sequencing. Members of the genera Exiguobacterium and Curtobacterium were dominant in the studied vegetal material. Two strains (RC18-1/2 and RC18-3/1) were selected for further studies. The pathogenicity test showed that plants inoculated with Curtobacterium sp. RC18-1/2 exhibited the same symptoms as those previously detected in the field. To our knowledge, this study provides the first evidence about the isolation of a Curtobacterium pathogenic strain in maize. Effective crop disease management will require the use of integrated strategies, such as resistant cultivars and/or biocontrol agents.

Lesión autoinducida por el paciente en la pandemia por COVID-19, una situación de recursos limitados. Revisión de tema / Patient self-induced lung injury in the COVID-19 pandemic, a resource-limited situation. Review

La ventilación mecánica invasiva (VMI) es una estrategia importante de manejo en el paciente con síndrome de dificultad respiratoria aguda (SDRA). En la pandemia por COVID-19 los innumerables casos de SDRA han llevado al uso de otros dispositivos de oxigenación no invasivos, que han expuesto al paciente a mayor esfuerzo respiratorio, evidenciándose lo que se conoce como "lesión pulmonar autoinducida por el paciente" (P-SILI, por sus siglas en inglés). El objetivo de esta revisión es exponer la evidencia científica disponible relacionada con este fenómeno en el contexto de la pandemia por COVID-19. Se realizó una revisión narrativa de la literatura del tema mencionado; la búsqueda se realizó hasta septiembre de 2020 en las bases de datos Medline, Embase, Central y Google Académico y se seleccionaron los artículos más representativos. La VMI es fundamental en el tratamiento del SDRA, pero en manos inexpertas puede generar lesión pulmonar por diferentes mecanismos. Por otro lado, el uso de otros dispositivos de ventilación no invasiva como la cánula nasal de alto flujo, podrían favorecer la P-SILI, una condición que al parecer, perpetúa la inflamación y lesión pulmonar inicial al paciente en respiración espontánea. La información disponible aún es insuficiente.

In the COVID-19 pandemic, invasive mechanical ventilation is an important management strategy in handling patients with acute respiratory distress syndrome (ARDS). The multitudinous ARDS cases have resulted in use of other non-invasive oxygenation devices, which expose the patient to a greater breathing effort, developing patient self-induced lung injury (PSILI). The goal of the present review is to present the available scientific evidence associated with this phenomenon in the context of the COVID-19 pandemic. A narrative literature review on the topic was performed with a search in MEDLINE, EMBASE, CENTRAL and Google Scholar databases until September 2020. Based on the abstracts the most representative articles were selected. Invasive mechanical ventilation (IVM) is essential in ARDS, however, in unexperienced hands it can lead to lung injury by different mechanisms. In other side, ARDS patients have been managed with other non-invasive ventilation devices, such as high-flow nasal cannula, which favor PSILI; a condition that apparently perpetuates initial lung lesion and inflammation by different mechanisms, when patients are submitted to spontaneous breathing. The information is still insufficient.

La educación en el estudiante de medicina. La transición de la universidad al hospital / Education in medical students. The transition from the university to the hospital

Resumen La acreditación en alta calidad otorgada a las instituciones universitarias para sus facultades de medicina no representa la calidad en educación durante el periodo de prácticas en las instituciones hospitalarias. Debido a la importancia de esta fase en el proceso académico del estudiante de medicina, es necesario considerar un cambio en el proceso educativo. Hay que explorar nuevos modelos pedagógicos fundamentados en el aprendizaje basado en problemas y con el uso de nuevas tecnologías para lograr una óptima formación médica.

Abstract The high-quality accreditation granted to universities for their medical schools does not represent the quality of education during practical rotations in the hospitals. Due to the importance of this phase in the medical students' academic process, a change in the educational process must be considered. New pedagogical models founded on problem-based learning and using new technologies to achieve optimal medical training must be explored.

Characterization of the bacteriocins and the PrtR regulator in a plant-associated Pseudomonas strain.

The emergence of antibiotic resistant bacterial strains demands the development of new antimicrobial agents. In the last decades, bacteriocins have gained significant interest due to their potential application as biopreservatives in the food industry and as therapeutic agents in medicine. Recent studies project the use of these antimicrobials in agriculture as biocontrol agents. The characterization of bacteriocins and their genetic regulation, however, have been scarcely studied in plant-associated bacteria. In this report, an in-silico and proteomic analysis was performed to identify the bacteriocins produced by Pseudomonas fluorescens SF4c. More than one functional bacteriocin was detected in this strain (S-type bacteriocins and phage-tail-like bacteriocins [tailocins]). It is known that the regulator PrtR represses bacteriocin production in P. aeruginosa under normal condition. However, the mechanism for tailocin regulation remains unknown in plant-associated pseudomonads. In this work, an orthologue of the prtR of P. aeruginosa was identified in the SF4c-tailocin cluster and a prtR null mutant constructed. The expression and production of tailocins was abolished in this mutant; thus evidencing that, unlike P. aeruginosa, PrtR is a positive regulator of tailocins expression in P. fluorescens.

Crisis gelásticas originadas en lóbulo temporal / Gelastic seizures originating in the temporal lobe

Las crisis gelásticas son una forma rara de epilepsia no convulsiva, más frecuente en población adulta joven y casi exclusiva de hamartomas hipotalámicos; sin embargo, hay otras localizaciones no hipotalámicas poco descritas en las cuales se presentan estas crisis, como el lóbulo temporal. El caso que presentamos muestra una manifestación atípica: un paciente de edad avanzada consultó por cambios en el comportamiento y risas inmotivadas; durante la hospitalización, se estableció la presencia de crisis gelásticas, las cuales fueron atribuidas a zona de gliosis temporal izquierda por antecedente de hematoma epidural en esta localización. Se concluye que este tipo de crisis epiléptica en población de la tercera edad es el resultado de etiologías distintas al hamartoma hipotalámico.

Gelastic seizures are a rare form of non-convulsive seizures, more common in young adults and almost exclusively of endocrine disorders and hypothalamic hamartomas, there another other places for this seizures as the temporal lobe. The case shows an atypical manifestation, an elderly patient who consults for changes in behavior and unmotivated laughter; during hospitalization, showed the presence of gelastic seizures, which were attributed to the left temporal area of gliosis by previous epidural hematoma at this location, we present clinical history, neuroimaging and EEG. In the conclusion on elderly, this type of seizure occurs by different etiologies and no only by hypothalamic hamartoma.