RESUMO
Plants adapt to fluctuating environmental conditions by adjusting their metabolism and gene expression to maintain fitness1. In legumes, nitrogen homeostasis is maintained by balancing nitrogen acquired from soil resources with nitrogen fixation by symbiotic bacteria in root nodules2-8. Here we show that zinc, an essential plant micronutrient, acts as an intracellular second messenger that connects environmental changes to transcription factor control of metabolic activity in root nodules. We identify a transcriptional regulator, FIXATION UNDER NITRATE (FUN), which acts as a sensor, with zinc controlling the transition between an inactive filamentous megastructure and an active transcriptional regulator. Lower zinc concentrations in the nodule, which we show occur in response to higher levels of soil nitrate, dissociates the filament and activates FUN. FUN then directly targets multiple pathways to initiate breakdown of the nodule. The zinc-dependent filamentation mechanism thus establishes a concentration readout to adapt nodule function to the environmental nitrogen conditions. In a wider perspective, these results have implications for understanding the roles of metal ions in integration of environmental signals with plant development and optimizing delivery of fixed nitrogen in legume crops.
Assuntos
Regulação da Expressão Gênica de Plantas , Nitratos , Fixação de Nitrogênio , Nódulos Radiculares de Plantas , Fatores de Transcrição , Zinco , Zinco/metabolismo , Fatores de Transcrição/metabolismo , Nitratos/metabolismo , Nódulos Radiculares de Plantas/metabolismo , Nitrogênio/metabolismo , Medicago truncatula/metabolismo , Medicago truncatula/genética , Simbiose , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMO
Global climate change has already brought noticeable alterations to multiple regions of our planet, including increased CO2 concentrations and changes in temperature. Several important steps of plant growth and development, such as embryogenesis, can be affected by such environmental changes; for instance, they affect how stored nutrients are used during early stages of seed germination during the transition from heterotrophic to autotrophic metabolism-a critical period for the seedling's survival. In this article, we briefly describe relevant processes that occur during embryo maturation and account for nutrient accumulation, which are sensitive to environmental change. Most of the nutrients stored in the seed during its development-including carbohydrates, lipids, and proteins, depending on the species-accumulate during the seed maturation stage. It is also known that iron, a key micronutrient for various electron transfer processes in plant cells, accumulates during embryo maturation. The existing literature indicates that climate change can not only affect the quality of the seed, in terms of total nutritional content, but also affect seed production. We discuss the potential effects of temperature and CO2 increases from an embryo-autonomous point of view, in an attempt to separate the effects on the parent plant from those on the embryo.
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Mudança Climática , Sementes , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Dióxido de Carbono/metabolismo , Germinação/fisiologia , TemperaturaRESUMO
Cu+ -chaperones are a diverse group of proteins that allocate Cu+ ions to specific copper proteins, creating different copper pools targeted to specific physiological processes. Symbiotic nitrogen fixation carried out in legume root nodules indirectly requires relatively large amounts of copper, for example for energy delivery via respiration, for which targeted copper deliver systems would be required. MtNCC1 is a nodule-specific Cu+ -chaperone encoded in the Medicago truncatula genome, with a N-terminus Atx1-like domain that can bind Cu+ with picomolar affinities. MtNCC1 is able to interact with nodule-specific Cu+ -importer MtCOPT1. MtNCC1 is expressed primarily from the late infection zone to the early fixation zone and is located in the cytosol, associated with plasma and symbiosome membranes, and within nuclei. Consistent with its key role in nitrogen fixation, ncc1 mutants have a severe reduction in nitrogenase activity and a 50% reduction in copper-dependent cytochrome c oxidase activity. A subset of the copper proteome is also affected in the ncc1 mutant nodules. Many of these proteins can be pulled down when using a Cu+ -loaded N-terminal MtNCC1 moiety as a bait, indicating a role in nodule copper homeostasis and in copper-dependent physiological processes. Overall, these data suggest a pleiotropic role of MtNCC1 in copper delivery for symbiotic nitrogen fixation.
Assuntos
Medicago truncatula , Fixação de Nitrogênio , Fixação de Nitrogênio/genética , Medicago truncatula/genética , Medicago truncatula/metabolismo , Cobre/metabolismo , Nódulos Radiculares de Plantas/metabolismo , Simbiose/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Iron is an essential micronutrient for life. During the development of the seed, iron accumulates during embryo maturation. In Arabidopsis thaliana, iron mainly accumulates in the vacuoles of only one cell type, the cell layer that surrounds provasculature in hypocotyl and cotyledons. Iron accumulation pattern in Arabidopsis is an exception in plant phylogeny, most part of the dicot embryos accumulate iron in several cell layers including cortex and, in some cases, even in protodermis. It remains unknown how does iron reach the internal cell layers of the embryo, and in particular, the molecular mechanisms responsible of this process. Here, we use transgenic approaches to modify the iron accumulation pattern in an Arabidopsis model. Using the SDH2-3 embryo-specific promoter, we were able to express VIT1 ectopically in both a wild type background and a mutant vit1 background lacking expression of this vacuolar iron transporter. These manipulations modify the iron distribution pattern in Arabidopsis from one cell layer to several cell layers, including protodermis, cortex cells, and the endodermis. Interestingly, total seed iron content was not modified compared with the wild type, suggesting that iron distribution in embryos is not involved in the control of the total iron amount accumulated in seeds. This experimental model can be used to study the processes involved in iron distribution patterning during embryo maturation and its evolution in dicot plants.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Ferro/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regiões Promotoras Genéticas/genética , Sementes/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
Iron is an essential nutrient for all life forms. Specialized mechanisms exist in bacteria to ensure iron uptake and its delivery to key enzymes within the cell, while preventing toxicity. Iron uptake and exchange networks must adapt to the different environmental conditions, particularly those that require the biosynthesis of multiple iron proteins, such as nitrogen fixation. In this review, we outline the mechanisms that the model diazotrophic bacterium Azotobacter vinelandii uses to ensure iron nutrition and how it adapts Fe metabolism to diazotrophic growth.
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Symbiotic nitrogen fixation carried out by the interaction between legumes and rhizobia is the main source of nitrogen in natural ecosystems and in sustainable agriculture. For the symbiosis to be viable, nutrient exchange between the partners is essential. Transition metals are among the nutrients delivered to the nitrogen-fixing bacteria within the legume root nodule cells. These elements are used as cofactors for many of the enzymes controlling nodule development and function, including nitrogenase, the only known enzyme able to convert N2 into NH3 . In this review, we discuss the current knowledge on how iron, zinc, copper, and molybdenum reach the nodules, how they are delivered to nodule cells, and how they are transferred to nitrogen-fixing bacteria within.
Assuntos
Fabaceae , Rhizobium , Fixação de Nitrogênio , Simbiose , Ecossistema , Fabaceae/microbiologia , Nódulos Radiculares de Plantas/microbiologia , NitrogênioRESUMO
Fundamento: la reanimación cardiopulmocerebral es el conjunto de maniobras para asegurar la oxigenación de los órganos cuando la circulación de la sangre se detiene. La reanimación cardiopulmocerebral intrahospitalaria es una intervención que salva vidas. Objetivo: caracterizar la atención médica durante la reanimación cardiopulmocerebral en pacientes que presentan parada cardiaca dentro del Hospital General Universitario Dr. Gustavo Aldereguía Lima de Cienfuegos. Método se realizó un estudio descriptivo, transversal en las cinco unidades de cuidados intensivos de la Vicedirección de Urgencias, entre enero hasta junio del 2020. Se estudiaron 152 pacientes que realizaron un paro cardiorespiratorio. Se estudiaron las variables relacionadas con el paciente, los síntomas y signos previos al PCR presentados por los pacientes así como signos vitales. Resultados la media de edad fue de 62,66 años, en el 54,6 % predominó el sexo masculino. La hipertensión arterial fue la comorbilidad más frecuente con un 60,5 %. El 32,9 % tuvo un tiempo de estadía previo al evento de más de 72 horas. En orden de frecuencia los signos o síntomas previos al evento de PCR con más presencia fueron: bradicardia (32,2 %); pulsos débiles (15,1 %); inconciencia (12,5 %) y cianosis con 10,5 %. El servicio de mayor de ocurrencia fue la Unidad de Cuidados Intensivos Clínica. La asistolia constituyó el ritmo eléctrico inicial más común (57,9 %). En el 100 % de los casos se realizó manejo avanzado de la vía aérea con tubo endotraqueal. La desfibrilación estuvo indicada en 42 pacientes donde el 15,1 % de estos recibió la primera desfibrilación en menos de 5 minutos. La causa de la suspensión de la reanimación en 95 de los pacientes estudiados fue el fallecimiento. Conclusiones: la atención médica ante el paro cardiorrespiratorio debe seguir perfeccionándose, a través de la superación del personal sanitario y el desarrollo de acciones organizativas hacia el proceso de reanimación cardiopulmocerebral intrahospitalaria.
Background: cardiopulmonary-cerebral resuscitation is the set of maneuvers to ensure oxygenation of organs when blood circulation stops. In-hospital cardiopulmonary-cerebral resuscitation is a life-saving intervention. Objective: to characterize medical care during cardiopulmonary-cerebral resuscitation in patients with cardiac arrest at the Dr. Gustavo Aldereguía Lima University General Hospital in Cienfuegos. Method: a descriptive, cross-sectional study was carried out in the five intensive care units of the Emergency Department, from January to June 2020. 152 patients who suffered cardiorespiratory arrest were studied. The variables related to the patient, the symptoms and signs presented by the patients prior to the PCR, as well as vital signs, were studied. Results: the average age was 62.66 years, in 54.6% the male sex predominated. Arterial hypertension was the most frequent comorbidity with 60.5%. 32.9% had a length of stay prior to the event of more than 72 hours. In order of frequency, the most prevalent signs or symptoms prior to the PCR event were: bradycardia (32.2%); weak pulses (15.1%); unconsciousness (12.5%) and cyanosis with 10.5%. The service with the highest occurrence was the Clinical Intensive Care Unit. Asystole was the most common initial electrical rhythm (57.9%). In 100% of the cases, advanced airway management was performed with an endotracheal tube. Defibrillation was indicated in 42 patients where 15.1% of these received the first defibrillation in less than 5 minutes. The cause of suspension of resuscitation in 95 of the patients studied was death. Conclusions: medical care in the face of cardiorespiratory arrest must continue to be improved, through the improvement of health personnel and the development of organizational actions towards the process of intrahospital cardiopulmonary-cerebral resuscitation.
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Fundamento: la reanimación cardiopulmocerebral básica está presente como curso propio en los planes de estudios "D" y "E" de la carrera de Medicina; aunque en ambos la organización del proceso tiene sus particularidades. Objetivo: precisar las diferencias en cuanto a estructura, proceso docente y resultados académicos en la enseñanza de la reanimación cardiopulmocerebral básica, entre los planes de estudios "D" y "E" de la carrera de Medicina. Métodos: se realizó un estudio descriptivo, prospectivo, transversal, en la Universidad de Ciencias Médicas de Cienfuegos en los años 2017 y 2019. Se utilizaron métodos teóricos y empíricos. Para comparar resultados se utilizó el universo estudiantil en ambos años, para evaluar satisfacción y calidad una muestra aleatoria simple. Se utilizaron técnicas de estadística descriptiva. Para ambos cursos se utilizó similar escenario y claustro de profesores. Resultados: las diferencias entre ambos planes derivan de los componentes no personales del proceso docente; el plan "D" tiene 20 horas y el "E" 40, con lo cual se amplían sus contenidos. Todos los temas y objetivos del plan "D" estuvieron incluidos en el "E". Hubo similitud en las promociones general (80.4 % y 75.2 %) y de calidad (50.6 % y 53.1 %) en ambos años. El cumplimiento de las expectativas, satisfacción y calidad del proceso fue valorado de muy alto y alto (más 98 %) por los estudiantes en ambos cursos. Conclusiones: aunque existieron diferencias en el proceso enseñanza aprendizaje entre ambos planes, no hubo repercusión en la satisfacción de los estudiantes, calidad del proceso docente, ni los resultados académicos. La variante del plan "E" es más integral para la formación básica del apoyo vital.
Background: basic cardiopulmonary-cerebral resuscitation is present as its own course in the "D" and "E" study plans of the Medicine career; although in both the organization of the process has its particularities. Objective: to specify the differences in terms of structure, teaching process and academic results in the teaching of basic cardiopulmonary-cerebral resuscitation, between the "D" and "E" study plans of the Medicine career. Methods: a descriptive, prospective, cross-sectional study was carried out at Cienfuegos University of Medical Sciences from 2017 to 2019. Theoretical and empirical methods were used. To compare results, the student universe was used in both years, to evaluate satisfaction and quality a simple random sample. Descriptive statistical techniques were used. For both courses, a similar scenario and faculty were used. Results: the differences between both plans derive from the non-personal components of the teaching process; plan "D" has 20 hours and plan "E" 40, which expands its contents. All the topics and objectives of plan "D" were included in plan "E". There was similarity in the general (80.4% and 75.2%) and quality (50.6% and 53.1%) school grades in both years. The fulfillment of the expectations, satisfaction and quality of the process was valued as very high and high (more than 98%) by the students in both courses. Conclusions: although there were differences in the teaching-learning process between both plans, there was no impact on student satisfaction, quality of the teaching process, or academic results. The "E" plan variant is more comprehensive for basic life support training.
Assuntos
Reanimação Cardiopulmonar , Educação Médica , Programas de Pós-Graduação em SaúdeRESUMO
Zinc is an essential nutrient at low concentrations, but toxic at slightly higher ones. It has been proposed that hyperaccumulator plants may use the excess zinc to fend off pathogens and herbivores. However, there is little evidence of a similar response in other plants. Here we show that Arabidopsis thaliana leaves inoculated with the necrotrophic fungus Plectosphaerella cucumerina BMM (PcBMM) accumulate zinc and manganese at the infection site. Zinc accumulation did not occur in a double mutant in the zinc transporters HEAVY METAL ATPASE2 and HEAVY METAL ATPASE4 (HMA2 and HMA4), which has reduced zinc translocation from roots to shoots. Consistent with a role in plant immunity, expression of HMA2 and HMA4 was up-regulated upon PcBMM inoculation, and hma2hma4 mutants were more susceptible to PcBMM infection. This phenotype was rescued upon zinc supplementation. The increased susceptibility to PcBMM infection was not due to the diminished expression of genes involved in the salicylic acid, ethylene, or jasmonate pathways since they were constitutively up-regulated in hma2hma4 plants. Our data indicate a role of zinc in resistance to PcBMM in plants containing ordinary levels of zinc. This layer of immunity runs in parallel to the already characterized defence pathways, and its removal has a direct effect on resistance to pathogens.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ascomicetos , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Zinco/metabolismoRESUMO
Yellow Stripe-Like (YSL) proteins are a family of plant transporters that are typically involved in transition metal homeostasis. Three of the four YSL clades (I, II and IV) transport metals complexed with the non-proteinogenic amino acid nicotianamine or its derivatives. No such capability has been shown for any member of clade III, but the link between these YSLs and metal homeostasis could be masked by functional redundancy. We studied the role of the clade III YSL protein MtSYL7 in Medicago truncatula nodules. MtYSL7, which encodes a plasma membrane-bound protein, is mainly expressed in the pericycle and cortex cells of the root nodules. Yeast complementation assays revealed that MtSYL7 can transport short peptides. M. truncatula transposon insertion mutants with decreased expression of MtYSL7 had lower nitrogen fixation rates and showed reduced plant growth whether grown in symbiosis with rhizobia or not. YSL7 mutants accumulated more copper and iron in the nodules, which is likely to result from the increased expression of iron uptake and delivery genes in roots. Taken together, these data suggest that MtYSL7 plays an important role in the transition metal homeostasis of nodules and symbiotic nitrogen fixation.
Assuntos
Medicago truncatula/fisiologia , Fixação de Nitrogênio/fisiologia , Proteínas de Plantas/metabolismo , Membrana Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Mutação , Proteínas de Plantas/genética , Raízes de Plantas/genética , Plantas Geneticamente Modificadas , Transporte Proteico , Rhizobium , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/metabolismo , SimbioseRESUMO
Legumes form a symbiosis with rhizobia that convert atmospheric nitrogen (N2) to ammonia and provide it to the plant in return for a carbon and nutrient supply. Nodules, developed as part of the symbiosis, harbor rhizobia that are enclosed in a plant-derived symbiosome membrane (SM) to form an organelle-like structure called the symbiosome. In mature nodules exchanges between the symbionts occur across the SM. Here we characterize Yellow Stripe-like 7 (GmYSL7), a Yellow stripe-like family member localized on the SM in soybean (Glycine max) nodules. It is expressed specifically in infected cells with expression peaking soon after nitrogenase becomes active. Unlike most YSL family members, GmYSL7 does not transport metals complexed with phytosiderophores. Rather, it transports oligopeptides of between four and 12 amino acids. Silencing GmYSL7 reduces nitrogenase activity and blocks infected cell development so that symbiosomes contain only a single bacteroid. This indicates the substrate of YSL7 is required for proper nodule development, either by promoting symbiosome development directly or by preventing inhibition of development by the plant. RNAseq of nodules where GmYSL7 was silenced suggests that the plant initiates a defense response against rhizobia with genes encoding proteins involved in amino acid export downregulated and some transcripts associated with metal homeostasis altered. These changes may result from the decrease in nitrogen fixation upon GmYSL7 silencing and suggest that the peptide(s) transported by GmYSL7 monitor the functional state of the bacteroids and regulate nodule metabolism and transport processes accordingly. Further work to identify the physiological substrate for GmYSL7 will allow clarification of this role.
Assuntos
Glycine max/genética , Proteínas de Membrana Transportadoras/genética , Fixação de Nitrogênio , Proteínas de Plantas/genética , Rhizobium/fisiologia , Transporte Biológico , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Plantas/metabolismo , Glycine max/metabolismo , Glycine max/microbiologia , SimbioseRESUMO
Arbuscular mycorrhizal fungi are critical participants in plant nutrition in natural ecosystems and in sustainable agriculture. A large proportion of the phosphorus, nitrogen, sulfur, and transition metal elements that the host plant requires are obtained from the soil by the fungal mycelium and released at the arbuscules in exchange for photosynthates. While many of the plant transporters responsible for obtaining macronutrients at the periarbuscular space have been characterized, the identities of those mediating transition metal uptake remain unknown. In this work, MtCOPT2 has been identified as the only member of the copper transporter family COPT in the model legume Medicago truncatula to be specifically expressed in mycorrhizal roots. Fusing a C-terminal GFP tag to MtCOPT2 expressed under its own promoter showed a distribution pattern that corresponds with arbuscule distribution in the roots. When expressed in tobacco leaves, MtCOPT2-GFP co-localizes with a plasma membrane marker. MtCOPT2 is intimately related to the rhizobial nodule-specific MtCOPT1, which is suggestive of a shared evolutionary lineage that links transition metal nutrition in the two main root endosymbioses in legumes.
Assuntos
Medicago truncatula , Proteínas de Membrana Transportadoras , Micorrizas , Ecossistema , Regulação da Expressão Gênica de Plantas , Medicago truncatula/genética , Medicago truncatula/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Micorrizas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , SimbioseRESUMO
Symbiotic nitrogen fixation carried out in legume root nodules requires transition metals. These nutrients are delivered by the host plant to the endosymbiotic nitrogen-fixing bacteria living within the nodule cells, a process in which vascular transport is essential. As members of the Yellow Stripe-Like (YSL) family of metal transporters are involved in root to shoot transport, they should also be required for root to nodule metal delivery. The genome of the model legume Medicago truncatula encodes eight YSL proteins, four of them with a high degree of similarity to Arabidopsis thaliana YSLs involved in long-distance metal trafficking. Among them, MtYSL3 is a plasma membrane protein expressed by vascular cells in roots and nodules and by cortical nodule cells. Reducing the expression level of this gene had no major effect on plant physiology when assimilable nitrogen was provided in the nutrient solution. However, nodule functioning was severely impaired, with a significant reduction of nitrogen fixation capabilities. Further, iron and zinc accumulation and distribution changed. Iron was retained in the apical region of the nodule, while zinc became strongly accumulated in the nodule veins in the ysl3 mutant. These data suggest a role for MtYSL3 in vascular delivery of iron and zinc to symbiotic nitrogen fixation.
Assuntos
Arabidopsis , Medicago truncatula , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Medicago truncatula/genética , Medicago truncatula/metabolismo , Fixação de Nitrogênio , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/metabolismo , SimbioseRESUMO
RESUMEN Los problemas de muerte súbita y reanimación cardiopulmocerebral intrahospitalarias pueden tener estructurada una respuesta común; sin embargo, en la mayoría de los hospitales no se dispone de una estrategia orientada a su solución. Este trabajo actualiza sobre las principales alternativas para reducir la letalidad por muerte súbita intrahospitalaria y presenta una propuesta del Hospital General de Cienfuegos. El abordaje institucional para mayor supervivencia y menor discapacidad ante la muerte súbita dependerá de iniciativas multidisciplinarias enfocadas a la calidad y prevención, en los diferentes eslabones, de la reanimación cardiopulmocerebral. Un hospital cardioprotegido integra procesos gerenciales, organizativos, asistenciales, académicos y logísticos para todos los eslabones de la cadena de supervivencia ante una emergencia médica, principalmente la parada cardíaca súbita. La propuesta del Hospital General de Cienfuegos como institución cardioprotegida agrupa todos los elementos de un sistema integrado de reanimación cardiopulmocerebral enfocado hacia la calidad, seguridad y satisfacción de pacientes y prestadores.
ABSTRACT In-hospital sudden death and cardiopulmonary cerebral resuscitation problems could have a common structured response. However, most hospitals lack a solution-oriented strategy. This paper provides detailed update on the main alternatives to reduce lethality of in-hospital sudden death and presents a proposal from the "Hospital General de Cienfuegos". The institutional approach for greater survival and lesser disability when facing sudden death will be based on multidisciplinary initiatives primarily centered on quality and prevention in the different stages of cardiopulmonary cerebral resuscitation. A cardio-protected hospital comprises management, organizational, assistance, academic and logistical processes for every single link of the survival chain in a medical emergency event, mainly sudden cardiac arrest. The proposal of the "Hospital General de Cienfuegos", a cardio-protected facility, brings together all elements of an integrated cardiopulmonary cerebral resuscitation system aimed at quality, safety and satisfaction of patients and caregivers.
Assuntos
Morte Súbita Cardíaca , Reanimação Cardiopulmonar , Morte Súbita , Equipe de Respostas Rápidas de Hospitais , Parada Cardíaca , HospitaisRESUMO
Iron is an essential cofactor for symbiotic nitrogen fixation, required by many of the enzymes involved, including signal transduction proteins, O2 homeostasis systems, and nitrogenase itself. Consequently, host plants have developed a transport network to deliver essential iron to nitrogen-fixing nodule cells. Ferroportin family members in model legume Medicago truncatula were identified and their expression was determined. Yeast complementation assays, immunolocalization, characterization of a tnt1 insertional mutant line, and synchrotron-based X-ray fluorescence assays were carried out in the nodule-specific M. truncatula ferroportin Medicago truncatula nodule-specific gene Ferroportin2 (MtFPN2) is an iron-efflux protein. MtFPN2 is located in intracellular membranes in the nodule vasculature and in inner nodule tissues, as well as in the symbiosome membranes in the interzone and early-fixation zone of the nodules. Loss-of-function of MtFPN2 alters iron distribution and speciation in nodules, reducing nitrogenase activity and biomass production. Using promoters with different tissular activity to drive MtFPN2 expression in MtFPN2 mutants, we determined that expression in the inner nodule tissues is sufficient to restore the phenotype, while confining MtFPN2 expression to the vasculature did not improve the mutant phenotype. These data indicate that MtFPN2 plays a primary role in iron delivery to nitrogen-fixing bacteroids in M. truncatula nodules.
Assuntos
Medicago truncatula , Regulação da Expressão Gênica de Plantas , Ferro/metabolismo , Medicago truncatula/genética , Medicago truncatula/metabolismo , Fixação de Nitrogênio , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/metabolismo , SimbioseRESUMO
RESUMEN La encefalopatía de Wernicke es un trastorno neurológico agudo y reversible debido a la deficiencia de tiamina. El alcoholismo crónico fue la causa principal en el pasado. Actualmente, existen muchas otras situaciones que favorecen esta afección: alimentación intravenosa prolongada, hiperémesis gravídica, anorexia nerviosa, enteritis regional, síndrome de malabsorción, hemodiálisis, diálisis peritoneal, cirugía abdominal y vómitos excesivos. Esta última causa fue precisamente la que llevó a la aparición de esta patología en una paciente de 31 años.Ella acude al Hospital Provincial de Cienfuegos con cuadro clínico de vómitos de más de un mes de duración, pérdida de peso y dolor abdominal, motivo por el cual fue intervenida quirúrgicamente donde se encontró plastrón yeyunal secundario a microperforación. Luego de su recuperación, se ingresa nuevamente 11 días después con cuadro de ataxia, desviación del ojo derecho hacia ángulo nasal por parálisis del VI par craneal y confusión mental. Se piensa prieramente en un Síndrome de Guillain Barré y, al realizarse una Resonancia Magnética Nuclear de cráneo, se prescribe la presencia de lesiones hipointensas relacionadas con la presencia de una Encefalopatía de Wernicke.
ABSTRACT Wernicke's encephalopathy is an acute and reversible neurological disorder due to thiamine deficiency. Chronic alcoholism was its cause in the past. Currently, there are many other conditions which favor this condition: prolonged intravenous feeding, hyperemesis gravidarum, anorexia nervosa, regional enteritis, malabsorption syndrome, hemodialysis, peritoneal dialysis, abdominal surgery and excessive vomiting. This last cause precisely led to the appearance of this pathology in a 31-year-old patient who went to the Provincial Hospital of Cienfuegos due to having repeated vomitings for more than a month, weight loss and abdominal pain, reason for which had a surgery where jejunal plastron secondary to microperforation was found.After recovery, she is admitted again 11 days later with ataxia, deviation of the right eye towards the nasal angle due to paralysis of the VI cranial nerve and mental confusion. Initially a Guillain Barré Syndrome is suspected but when performing a Skull Nuclear Magnetic Resonance, the presence of hypointense lesions leads to the diagnosis of Wernicke's Encephalopathy.
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RESUMEN Fundamento: las arbovirosis se encuentran dentro de las principales enfermedades infecciosas que afectan a las regiones tropicales. Dentro de este grupo el dengue juega un papel preponderante. Objetivo: describir la manera en que se organizaron los servicios médicos en el Hospital Dr. Gustavo Aldereguía Lima de la provincia de Cienfuegos durante el enfrentamiento a un brote de casos sospechosos de arbovirosis. Métodos: investigación descriptiva en el ámbito de la organización hospitalaria de servicios de salud ante situaciones de epidemia. Se desarrolló entre los meses de mayo a diciembre de 2018 en el hospital de Cienfuegos. Resultados: fue creado un grupo operativo para liderar las acciones relacionadas con el brote epidémico, se capacitó el recurso humano en función de este. Se reorganizaron los flujos en el servicio clínico de urgencia para readecuarlos a las nuevas prestaciones; fue detenida la actividad quirúrgica electiva del hospital. Se dispuso de 150 camas para la atención a los pacientes con sospecha de arbovirosis. Fueron ingresadas todas las gestantes sospechosas. No se reportaron pacientes fallecidos por esta causa. Conclusiones: la organización de la actividad hospitalaria en el enfrentamiento a la arbovirosis fue efectiva.
ABSTRACT Foundation: arbovirus infections are among the main diseases that affect tropical regions. Within this group, dengue plays a preponderant role. Objective: to describe the organization of medical services in the Dr. Gustavo Aldereguía Lima Hospital in the province of Cienfuegos during the outbreak of cases suspected of arbovirus infections. Methods: descriptive research in the field of the hospital organization of health services in epidemic situations. It was developed between the months of May to December 2018 in the hospital of Cienfuegos. Results: an operative group was created to lead the actions related to the epidemic outbreak for which human resources were trained. The emergency clinical service flow was reorganized to readjust them to the new situation; the elective surgical activity of the hospital was stopped. 150 beds were available for caring of patients with suspected arbovirus infection. All suspicious pregnant women were admitted. No patients were reported dead due to this cause. Conclusions: the organization of the hospital activity in the arbovirus infection outbreak was effective.
RESUMO
Genetic ablation of the ß subunit of the heterotrimeric G protein complex in agb1-2 confers defective activation of microbe-associated molecular pattern (MAMP)-triggered immunity, resulting in agb1-2 enhanced susceptibility to pathogens like the fungus Plectosphaerella cucumerina BMM. A mutant screen for suppressors of agb1-2 susceptibility (sgb) to P. cucumerina BMM identified sgb10, a new null allele (mkp1-2) of the mitogen-activated protein kinase phosphatase 1 (MKP1). The enhanced susceptibility of agb1-2 to the bacterium Pseudomonas syringae pv. tomato DC3000 and the oomycete Hyaloperonospora arabidopsidis is also abrogated by mkp1-2. MKP1 negatively balances production of reactive oxygen species (ROS) triggered by MAMPs, since ROS levels are enhanced in mkp1. The expression of RBOHD, encoding a NADPH oxidase-producing ROS, is upregulated in mkp1 upon MAMP treatment or pathogen infection. Moreover, MKP1 negatively regulates RBOHD activity, because ROS levels upon MAMP treatment are increased in mkp1 plants constitutively overexpressing RBOHD (35S::RBOHD mkp1). A significant reprograming of mkp1 metabolic profile occurs with more than 170 metabolites, including antimicrobial compounds, showing differential accumulation in comparison with wild-type plants. These results suggest that MKP1 functions downstream of the heterotrimeric G protein during MAMP-triggered immunity, directly regulating the activity of RBOHD and ROS production as well as other immune responses.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Proteínas Tirosina Fosfatases , Arabidopsis/imunologia , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ascomicetos/fisiologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas/genética , Proteínas Tirosina Fosfatases/genética , Proteínas Tirosina Fosfatases/metabolismo , Pseudomonas syringae/fisiologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Symbiotic nitrogen fixation carried out by the interaction between legumes and diazotrophic bacteria known as rhizobia requires relatively large levels of transition metals. These elements are cofactors of many key enzymes involved in this process. Metallic micronutrients are obtained from soil by the roots and directed to sink organs by the vasculature, in a process mediated by a number of metal transporters and small organic molecules that facilitate metal delivery in the plant fluids. Among the later, nicotianamine is one of the most important. Synthesized by nicotianamine synthases (NAS), this molecule forms metal complexes participating in intracellular metal homeostasis and long-distance metal trafficking. Here we characterized the NAS2 gene from model legume Medicago truncatula. MtNAS2 is located in the root vasculature and in all nodule tissues in the infection and fixation zones. Symbiotic nitrogen fixation requires of MtNAS2 function, as indicated by the loss of nitrogenase activity in the insertional mutant nas2-1, phenotype reverted by reintroduction of a wild-type copy of MtNAS2. This would result from the altered iron distribution in nas2-1 nodules shown with X-ray fluorescence. Moreover, iron speciation is also affected in these nodules. These data suggest a role of nicotianamine in iron delivery for symbiotic nitrogen fixation.
RESUMO
Fundamento: La realización de una correcta reanimación cardiopulmocerebral modifica positivamente la supervivencia de la parada cardíaca, por lo que tener personal capacitado es decisivo para ello.Objetivo: Determinar el conocimiento del personal de enfermería sobre sus acciones dirigidas en la reanimación cardiopulmocerebral.Método: Se realizó un estudio descriptivo, prospectivo, longitudinal, en el Centro Provincial de Emergencias Médicas del Hospital General de Cienfuegos en los años 2014 y 2017. En ambos años, se aplicó similar cuestionario con preguntas sobre acciones de enfermería en reanimación cardiopulmocerebral, luego de intervención educativa con nueva guía de práctica clínica.Resultados: El grupo estuvo constituido por 82 enfermeros, principalmente licenciados (67.1 %) y con ≥ 10 años de experiencia en el servicio de urgencias. De las 19 acciones definidas para la reanimación cardiopulmonar e incluidas en la guía de actuación,15 (78.94 %) tuvieron 100 % de respuestas correctas en ambos años. Entre las acciones básicas, la dificultad más frecuente fue el reconocimiento de la monitorización clínica y electrónica; mientras que en cuanto a las acciones complementarias el brindar apoyo psicológico a los familiares constituyó el principal problema cognitivo.Conclusiones: El nivel de conocimientos para acciones básicas, específicas y complementarias para la reanimación cardiopulmocerebral en el personal de enfermería fue alto, principalmente en la segunda medición. Pudieron influir en ello, el disponer de un protocolo de actuación, el entrenamiento frecuente con situaciones reales y la estabilidad laboral por más de 10 años del personal en el servicio de urgencias.
Foundation: the correct execution of cardiac-pulmonary-cerebral resuscitation modifies cardiac failure survival, thus counting on qualified personnel is decisive for that. Objective: to determine the knowledge of the nursing personnel about actions towards cardiac-pulmonary-cerebral resuscitation. Method: a longitudinal, prospective and descriptive study was developed at the Provincial Center of Medical Emergencies in the Cienfuegos Hospital during the years 2014 and 2017. In both years, the same questionnaire was applied containing questions about the nursing actions in cardiac- pulmonary-cerebral resuscitation, after an educative intervention with the new guideline of clinical practice. Results: 82 nurses constituted the group; mainly university graduates (67.1 %) and with ≥ 10 years of experience in the emergency service. From de 19 defined actions for cardiac- pulmonary-cerebral resuscitation and includes those of an action guideline, 15 (78.94 %) had 100% correct answers in both Conclusion: the level of knowledge for basic, specific and complementary actions in cardiac- pulmonary-cerebral resuscitation in nursing personnel was high, mainly in the second measurement. In this situation, it could have influenced the availability of an action protocol, the frequent training in real situations and the employment stability for more than 10 years of the emergency service personnel.