Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
1.
Proc Natl Acad Sci U S A ; 121(15): e2321975121, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38557190

RESUMO

Monocarpic plants have a single reproductive phase in their life. Therefore, flower and fruit production are restricted to the length of this period. This reproductive strategy involves the regulation of flowering cessation by a coordinated arrest of the growth of the inflorescence meristems, optimizing resource allocation to ensure seed filling. Flowering cessation appears to be a regulated phenomenon in all monocarpic plants. Early studies in several species identified seed production as a major factor triggering inflorescence proliferative arrest. Recently, genetic factors controlling inflorescence arrest, in parallel to the putative signals elicited by seed production, have started to be uncovered in Arabidopsis, with the MADS-box gene FRUITFULL (FUL) playing a central role in the process. However, whether the genetic network regulating arrest is also at play in other species is completely unknown. Here, we show that this role of FUL is not restricted to Arabidopsis but is conserved in another monocarpic species with a different inflorescence structure, field pea, strongly suggesting that the network controlling the end of flowering is common to other plants. Moreover, field trials with lines carrying mutations in pea FUL genes show that they could be used to boost crop yield.


Assuntos
Flores , Proteínas de Domínio MADS , Pisum sativum , Arabidopsis/genética , Arabidopsis/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Pisum sativum/genética , Pisum sativum/metabolismo , Proteínas de Domínio MADS/genética , Proteínas de Domínio MADS/metabolismo , Proteínas de Ervilha/genética
3.
Front Nutr ; 10: 1218266, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38075215

RESUMO

Background and aims: The diagnosis of malnutrition in post-critical COVID-19 patients is challenging as a result of the high prevalence of obesity, as well as the variability and previously reported inconsistencies across currently available assessment methods. Bioelectrical impedance vector analysis (BIVA) with phase angle (PhA) and nutritional ultrasound (NU®) are emerging techniques that have been proven successful in assessing body composition with high precision in previous studies. Our study aims to determine the performance and usefulness of PhA and rectus femoris cross-sectional area (RF-CSA) measurements in assessing body composition as part of the full routine morphofunctional assessment used in the clinical setting, as well as their capacity to predict severe malnutrition and to assess complications and aggressive therapy requirements during recent intensive care unit (ICU) admission, in a cohort of post-critically ill COVID-19 outpatients. Methods: This prospective observational study included 75 post-critical outpatients who recovered from severe COVID-19 pneumonia after requiring ICU admission. Correlations between all the morphofunctional parameters, complications, and aggressive therapy requirements during admission were analyzed. Multivariate logistic regression analysis and ROC curves were provided to determine the performance of NU® and PhA to predict severe malnutrition. Differences in complications and aggressive therapy requirements using the cutoff points obtained were analyzed. Results: In total, 54.7% of patients were classified by Subjective Global Assessment (SGA) as SGA-B and 45.3% as SGA-C, while 78.7% met the Global Leadership Initiative of Malnutrition (GLIM) criteria. PhA correlates positively with body cell mass/height (BCM/h) (r = 0.74), skeletal muscle index (SMI) (r = 0.29), RF-CSA (r = 0.22), RF-Y axis (r = 0.42), and handgrip strength (HGS) assessed using dynamometry (r = 0.42) and the Barthel scale (r = 0.29) and negatively with ICU stay (r = -0.48), total hospital stay (r = -0.57), need for invasive mechanical ventilation (IMV) (r = -0.39), days of IMV (r = -0.41), need for tracheostomy (r = -0.51), and number of prone maneuvers (r = -0.20). RF-CSA correlates positively with BCM/h (r = 0.41), SMI (r = 0.58), RF-Y axis (r = 0.69), and HGS assessed using dynamometry (r = 0.50) and the Barthel scale (r = 0.15) and negatively with total hospital stay (r = -0.22) and need for IMV (r = -0.28). Cutoff points of PhA < 5.4° and standardized phase angle (SPhA) < -0.79 showed good capacity to predict severe malnutrition according to SGA and revealed differences in ICU stay, total hospital stay, number of prone maneuvers, need for IMV, and need for rehabilitation, with statistical significance (p < 0.05). An RF-CSA/h < 2.52 cm2/m (for men) and <2.21 cm2/m (for women) also showed good performance in predicting severe malnutrition and revealed differences with statistical significance (p < 0.05) in ICU stay and total hospital stay. Conclusion: More than 75% of the post-critical COVID-19 survivors had malnutrition, and approximately half were obese. PhA, SPhA, RF-CSA, and RF-CSA/h, when applied to the assessment of body composition in post-critical COVID-19 patients, showed moderate-to-high correlation with other morphofunctional parameters and good performance to predict severe malnutrition and to assess complications and aggressive therapy requirements during ICU admission. Besides being readily available methods, BIVA and NU® can help improve the morphofunctional assessment of malnutrition in post-critical COVID-19 survivors; however, more studies are needed to assess the performance of these methods in other populations.

4.
Nutr Hosp ; 40(Spec No2): 9-11, 2023 Nov 22.
Artigo em Espanhol | MEDLINE | ID: mdl-37929905

RESUMO

Introduction: The microbes that reside in our human body make up our microbiota, and their genes are known as the microbiome. The gut microbiota is involved in a wide variety of functions. At present there is considerable evidence indicating that in the last 60 years there has been an important change in the composition of our microbiota. Dietary changes have been shown to have important effects on the microbiota in a very short space of time. The Mediterranean diet pattern causes changes in the microbiota towards a healthier profile. The changes induced by the Mediterranean diet could be explained, to a large extent, by its richness in polyphenols.


Introducción: Los microbios que residen dentro y sobre el cuerpo humano constituyen nuestra microbiota y sus genes se conocen como microbioma. La microbiota del intestino está implicada en una gran variedad de funciones. En el momento actual, hay bastantes evidencias que indican que en los últimos 60 años se ha producido un importante cambio en la composición de nuestra microbiota. Los cambios dietéticos han mostrado tener importantes efectos sobren la microbiota en muy corto espacio de tiempo. El patrón de dieta mediterránea provoca cambios en la microbiota hacia un perfil más saludable. Los cambios que induce la dieta mediterránea podrían explicarse, en gran medida, por la riqueza en polifenoles de la misma.


Assuntos
Dieta Mediterrânea , Microbioma Gastrointestinal , Microbiota , Humanos , Estado Nutricional , Polifenóis , Dieta
5.
Nutrients ; 15(20)2023 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-37892547

RESUMO

BACKGROUND: The value of the phase angle (PhA), measured via bioelectrical impedance analysis (BIA), could be considered a good marker of the cell mass and the cell damage of a patient; however, there are new techniques, such as muscle ultrasonography, that allow the quantity and quality of muscle to be assessed in a minimally invasive way. The aim of this study is to determine the prognostic value of morphofunctional techniques in the prognosis of mortality in patients with idiopathic pulmonary fibrosis (IPF). METHODS: This multicenter, cross-sectional study included 86 patients with idiopathic pulmonary fibrosis with a mean age of 71 years, 82.7% of whom were male. The nutritional risk of the patients was assessed by means of questionnaires, such as the Subjective Global Assessment (SGA), and non-invasive functional techniques, including BIA, nutritional ultrasound, and hand grip strength (HGS). Statistical analysis of the sample was performed using JAMOVI version 2.3.22. RESULTS: Correlations were made between the RF-CSA techniques with PhA (r = 0.48, p < 0.001), BCM (r = 0.70, p < 0.001), SMI (r = 0.64, p < 0.001), and HGS (r = 0.54, p < 0.001). The cut-off points for 12-month mortality were PhA = 4.5° (AUC = 0.722, sensitivity of 72.7% and specificity of 66.6%), BCM = 28.8 kg (AUC = 0.609, sensitivity of 32.4% and specificity of 100.0%), RF-CSA = 3.00 cm2 (AUC = 0.857, sensitivity of 64.4% and specificity of 100.0%), 6MMW = 420 m (AUC = 0.830, sensitivity of 63.27% and specificity of 100.0%), and TUG = 7.2 s (AUC = 0.771, sensitivity of 100.0% and specificity of 56.67%). In addition, a multivariate analysis was performed with RF-CSA, HR = 8.11 (1.39-47.16, p = 0.020), and PhA of 6.35 (1.29-31.15, p = 0.023), taking into account age, sex, and BMI to determine mortality. Finally, a Kaplan-Meier survival analysis was conducted with low or normal values for classical parameters (GAP and T6MM) and new parameters (PhA, BCM, RF-CSA, and TUG). CONCLUSION: RF-CSA and PhA were shown to be good prognostic markers of 12-month mortality and could, therefore, be useful screening tools to complement the nutritional assessment of IPF patients.


Assuntos
Força da Mão , Estado Nutricional , Humanos , Masculino , Idoso , Feminino , Músculo Quadríceps/diagnóstico por imagem , Estudos Transversais , Avaliação Nutricional , Impedância Elétrica
6.
Nutr Hosp ; 40(4): 686-691, 2023 Aug 28.
Artigo em Espanhol | MEDLINE | ID: mdl-37409710

RESUMO

Introduction: Introduction: oral nutritional supplements specific for diabetes (DSF) usually have a composition that favors their palatability and simultaneous glycemic and metabolic control. Objetive: to compare the sensory acceptability of a DSF with respect to a standard oral nutritional supplement (STF) in patients at risk of malnutrition with type 2 diabetes mellitus. Method: randomized, double-blind, crossover, multicenter, controlled, double-blind clinical trial. Odor, taste and perceived texture of a DSF and a STD were evaluated using a scale of 1 to 4. Results: twenty-nine patients were recruited and 58 organoleptic evaluations of the supplements were registered. A better evaluation of DSF was observed with respect to STD, although no statistically significant differences were reached: odor, 0.04 (CI 95 %) -0.49 to 0.56 (p = 0.092); taste, 0.14 (CI 95 %), -0.35 to 0.63 (p = 0.561); texture, 0.14 (CI 95 %), -0.43 to 0.72 (p = 0.619). No differences were found when analyzed by order of randomization, sex, degree of malnutrition, greater or lesser degree of complexity, greater or lesser time of evolution of diabetes, or by being older or younger. Conclusions: the specific nutritional supplement for diabetic patients formulated with extra virgin olive oil, EPA and DHA, a specific mixture of carbohydrates, and fiber, presented an adequate sensory acceptance by malnourished patients with type 2 diabetes mellitus.


Introducción: Introducción: las fórmulas nutricionales específicas para diabetes (FED) suelen presentar una composición que favorece simultáneamente su palatabilidad y el control glucémico y metabólico. Objetivo: comparar la aceptación sensorial de un FED respecto a un suplemento nutricional oral estándar (FE) en pacientes en riesgo de desnutrición con diabetes mellitus tipo 2. Método: ensayo clínico, aleatorizado, doble ciego, cruzado, multicéntrico y controlado. Se evaluó, a través de una escala del 1 al 4, el olor, el sabor y la textura percibida de un FED y de un FE. Resultados: se reclutaron a 29 pacientes y 58 evaluaciones sensoriales de los suplementos. Se observó una mejor valoración de la FED respecto a la FE, aunque no se alcanzaron diferencias estadísticamente significativas: olor, 0,04 (IC 95 %), de -0,49 a 0,56 (p = 0,092); sabor, 0,14 (IC 95 %), de -0,35 a 0,63 (p = 0,561); textura, 0,14, (IC 95 %), de -0,43 a 0,72 (p = 0,619). No se encontraron diferencias cuando se analizaron por orden de aleatorización, sexo, grado de desnutrición, mayor o menor grado de complejidad, mayor o menor tiempo de evolución de la diabetes, ni por ser más o menos mayores. Conclusiones: el suplemento nutricional específico para paciente con diabetes, formulado con aceite de oliva virgen extra, EPA y DHA, una mezcla específica en hidratos de carbono, fibra soluble e insoluble, presentó una adecuada aceptación sensorial del paciente desnutrido con diabetes mellitus tipo 2.


Assuntos
Diabetes Mellitus Tipo 2 , Suplementos Nutricionais , Desnutrição , Azeite de Oliva , Humanos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/dietoterapia , Desnutrição/dietoterapia , Desnutrição/etiologia , Sensação , Estudos Cross-Over
7.
Nutr Hosp ; 40(4): 692-700, 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37409714

RESUMO

Introduction: Introduction: there is controversy about the usefulness of specific enteral nutrition formulas in malnourished patients with diabetes. The effects on blood glucose and other aspects of metabolic control are not fully understood in the scientific literature. Objective: the aim of the study was to compare the glycaemic and insulinaemic response of patients with type 2 diabetes at risk of malnutrition after oral feed between a diabetes-specific formula with AOVE (DSF) and a standard one (STF). Methods: A randomized, double-blind, crossover, multicentre clinical trial was conducted in patients with type 2 diabetes at risk of malnutrition (SGA). The patients were randomized to receive either DSF or STF, a week apart. A glycaemia and insulinaemia curve was made at times 0 minutes, 30 min, 60 min, 90 min, 120 min, and 180 min after the patients drank 200 ml of the oral nutritional supplement (ONS). The principal variables were the area under the curve (AUC0-t) of glucose and insulin. Results: 29 patients (51 % women) were included, who were on average 68.84 (SD 11.37) years old. Regarding the degree of malnutrition, 86.2 % presented moderate malnutrition (B) and 13.8 % severe (C). When the patients received the DSF, they had a lower mean of glucose AUC0-t (-3,325.34 mg/min/dl [95 % CI: -4,3608.34 to -2,290.07]; p = 0.016) and also a lower mean of insulin AUC0-t (-451.14 uU/min/ml [95 % CI: -875,10 to -27.17]; p = 0.038). There were no differences in the degree of malnutrition. Conclusion: compared with STF, DSF with AOVE showed a better glycaemic and insulinaemic response in patients with type 2 diabetes at risk of malnutrition.


Introducción: Introducción: la utilidad de las fórmulas específicas de nutrición enteral en el paciente desnutrido con diabetes resulta controvertida. Sus efectos sobre la glucosa en sangre y otros aspectos del control metabólico no se conocen del todo en la literatura científica. Objetivo: el objetivo del estudio fue comparar la respuesta glucémica e insulinémica de los pacientes con diabetes tipo 2 (DM2) en riesgo de desnutrición tras la ingesta oral de una fórmula específica para diabetes (DSF) con aceite de oliva virgen extra (AOVE) y una estándar (STF). Métodos: ensayo clínico aleatorizado, doble ciego, cruzado y multicéntrico enpacientes con DM2 en riesgo de desnutrición (SGA). Los pacientes se asignaron aleatoriamente para recibir DSF o STF con una semana de diferencia. Se realizó una curva de glucemia e insulinemia en los siguientes tiempos: 0 minutos, 30 min, 60 min, 90 min, 120 min y 180 min tras la ingesta de 200 ml del suplemento nutricional oral (SNO). Las variables principales fueron el área bajo la curva (AUC0-t) de glucosa e insulina. Resultados: se incluyeron 29 pacientes (51 % mujeres), con una edad media de 68,84 años (DE 11,37). En cuanto al grado de desnutrición, el 86,2 % presentaba desnutrición moderada (B) y el 13,8 %, severa (C). Cuando los pacientes recibieron DSF tuvieron una media más baja de AUC0-t de glucosa (-3325,34 mg/min/dl [IC 95 %: de -4.3608,34 a -2.290,07]; p = 0,016) y también una media más baja de AUC0-t de insulina (-451,14 uU/min/ml [IC 95 %: de -875,10 a -27,17]; p = 0,038) respecto a cuando recibieron STF. No hubo diferencias por el grado de desnutrición. Conclusión: la fórmula con AOVE específica para diabetes mostró una mejor respuesta glucémica e insulinémica en pacientes con diabetes tipo 2 en riesgo de desnutrición respecto a una fórmula estándar.


Assuntos
Diabetes Mellitus Tipo 2 , Desnutrição , Humanos , Feminino , Criança , Masculino , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/terapia , Azeite de Oliva , Glicemia/metabolismo , Insulina , Desnutrição/etiologia , Desnutrição/terapia , Estudos Cross-Over
8.
Endocrinol Diabetes Nutr (Engl Ed) ; 70 Suppl 1: 74-84, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36935167

RESUMO

Nutritional ultrasound® is a new concept that uses ultrasound to assess body composition. It is composed of the evaluation of fat-free mass and fat mass. It is an emerging, economical, portable, non-invasive technique that evaluates the musculoskeletal area with linear, broadband, multifrequency probes, with a depth field of 20-100mm. It quantifies muscle modifications in malnutrition and provides information on functional changes (echogenicity). Although there are no validated specific cut-off points, the anterior rectum area of the quadriceps can be used as a criterion for malnutrition. The distribution of adipose tissue provides information on the energy reserve and the inflammatory pattern. It is important to integrate nutritional ultrasound® measures in clinical practice adapted to different settings and pathologies. It is necessary to establish training plans in nutritional ultrasound® for use by Endocrinology and Nutrition Specialists, with the aim of improving the diagnosis and treatment of their patients.


Assuntos
Formação de Conceito , Desnutrição , Humanos , Composição Corporal , Estado Nutricional , Ultrassonografia
9.
Int J Mol Sci ; 23(22)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36430591

RESUMO

LEAFY plant-specific transcription factors, which are key regulators of flower meristem identity and floral patterning, also contribute to meristem activity. Notably, in some legumes, LFY orthologs such as Medicago truncatula SINGLE LEAFLET (SGL1) are essential in maintaining an undifferentiated and proliferating fate required for leaflet formation. This function contrasts with most other species, in which leaf dissection depends on the reactivation of KNOTTED-like class I homeobox genes (KNOXI). KNOXI and SGL1 genes appear to induce leaf complexity through conserved downstream genes such as the meristematic and boundary CUP-SHAPED COTYLEDON genes. Here, we compare in M. truncatula the function of SGL1 with that of the Arabidopsis thaliana KNOXI gene, SHOOT MERISTEMLESS (AtSTM). Our data show that AtSTM can substitute for SGL1 to form complex leaves when ectopically expressed in M. truncatula. The shared function between AtSTM and SGL1 extended to the major contribution of SGL1 during floral development as ectopic AtSTM expression could promote floral organ identity gene expression in sgl1 flowers and restore sepal shape and petal formation. Together, our work reveals a function for AtSTM in floral organ identity and a higher level of interchangeability between meristematic and floral identity functions for the AtSTM and SGL1 transcription factors than previously thought.


Assuntos
Arabidopsis , Medicago truncatula , Medicago truncatula/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Mutação , Folhas de Planta/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
Front Plant Sci ; 13: 765095, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36212341

RESUMO

Inflorescence architecture contributes to essential plant traits. It determines plant shape, contributing to morphological diversity, and also determines the position and number of flowers and fruits produced by the plant, thus influencing seed yield. Most legumes have compound inflorescences, where flowers are produced in secondary inflorescences (I2), formed at the flanks of the main primary inflorescence (I1), in contrast to simple inflorescences of plants like Arabidopsis, in which flowers are directly formed on the I1. The pea VEGETATIVE1/FULc (VEG1) gene, and its homologs in other legumes, specify the formation of the I2 meristem, a function apparently restricted to legumes. To understand the control of I2 development, it is important to identify the genes working downstream of VEG1. In this study, we adopted a novel strategy to identify genes expressed in the I2 meristem, as potential regulatory targets of VEG1. To identify pea I2-meristem genes, we compared the transcriptomes of inflorescence apices from wild-type and mutants affected in I2 development, such as proliferating inflorescence meristems (pim, with more I2 meristems), and veg1 and vegetative2 (both without I2 meristems). Analysis of the differentially expressed genes using Arabidopsis genome databases combined with RT-qPCR expression analysis in pea allowed the selection of genes expressed in the pea inflorescence apex. In situ hybridization of four of these genes showed that all four genes are expressed in the I2 meristem, proving our approach to identify I2-meristem genes was successful. Finally, analysis by VIGS (virus-induced gene silencing) in pea identified one gene, PsDAO1, whose silencing leads to small plants, and another gene, PsHUP54, whose silencing leads to plants with very large stubs, meaning that this gene controls the activity of the I2 meristem. PsHUP54-VIGS plants are also large and, more importantly, produce large pods with almost double the seeds as the control. Our study shows a new useful strategy to isolate I2-meristem genes and identifies a novel gene, PsHUP54, which seems to be a promising tool to improve yield in pea and in other legumes.

11.
Endocrinol Diabetes Nutr (Engl Ed) ; 69(7): 466-475, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35989228

RESUMO

INTRODUCTION: Patients with gastroenteropancreatic neuroendocrine tumors (GEPNET) can suffer from malnutrition. This is the first descriptive study of morfo-functional evaluation in GEPNET. OBJETIVES: To describe a morfo-functional evaluation, and to compare with reference population available, and to correlate different nutritional parameters. Moreover, to compare nutritional evaluation in our study with another same location non-neuroendocrine tumors. MATERIALS AND METHODS: A retrospective observational study, 50 patients with GEPNET, medium age 61 years. It was collected clinico-pathological characteristics and nutritional status was assessed by anthropometric, laboratory test, bioelectrical impedance analysis, phase angle, hand grip strength, and rectus femoris ultrasound for the assessment of muscle mass. We used SPSS statistics to describe and to analyze correlations of different variables. RESULTS: Most frequent location of tumor was pancreas and small bowel, tumor grade 1 and advance stage. In morfo-functional evaluation highlighted: a low fat mass percentage (23,5 vs 34,4%), low muscle mass percentage (36,5 vs 41,2%) and low body mass cell percentage (40,4 vs 48,8%) compared with reference population available by sex and age. Standarized phase angle by sex and age result as positive (+0,851). There was no difference in hand grip strength compared with reference population. After a review of differents studies available, phase angle and hand grip strength of non neuroendocrine tumors in same location, could suggest a minor affection of nutritional state in our GEPNET sample. A positive correlation was observed between non classic methods of nutritional evaluation such as bioelectrical impedance analysis, hand grip strength and rectus femoris ultrasound. CONCLUSION: Patients with gastroenteropancreatic neuroendocrine tumors (GEPNET) show a moderate affection of nutritional status in comparison to general population. Morphofunctional assessment provide us a precise knowledge about nutritional status.


Assuntos
Neoplasias Intestinais , Tumores Neuroendócrinos , Força da Mão , Humanos , Pessoa de Meia-Idade , Estado Nutricional , Estudos Observacionais como Assunto , Neoplasias Pancreáticas , Neoplasias Gástricas
13.
New Phytol ; 234(3): 827-836, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35122280

RESUMO

Legumes usually have compound inflorescences, where flowers/pods develop from secondary inflorescences (I2), formed laterally at the primary inflorescence (I1). Number of flowers per I2, characteristic of each legume species, has important ecological and evolutionary relevance as it determines diversity in inflorescence architecture; moreover, it is also agronomically important for its potential impact on yield. Nevertheless, the genetic network controlling the number of flowers per I2 is virtually unknown. Chickpea (Cicer arietinum) typically produces one flower per I2 but single flower (sfl) mutants produce two (double-pod phenotype). We isolated the SFL gene by mapping the sfl-d mutation and identifying and characterising a second mutant allele. We analysed the effect of sfl on chickpea inflorescence ontogeny with scanning electron microscopy and studied the expression of SFL and meristem identity genes by RNA in situ hybridisation. We show that SFL corresponds to CaRAX1/2a, which codes a MYB transcription factor specifically expressed in the I2 meristem. Our findings reveal SFL as a central factor controlling chickpea inflorescence architecture, acting in the I2 meristem to regulate the length of the period for which it remains active, and therefore determining the number of floral meristems that it can produce.


Assuntos
Cicer , Inflorescência , Cicer/genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Inflorescência/genética , Meristema/genética , Mutação/genética , Fatores de Transcrição/genética
16.
Front Plant Sci ; 12: 765277, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34777450

RESUMO

Redox homeostasis has been linked to proper anther and pollen development. Accordingly, plant cells have developed several Reactive Oxygen Species (ROS)-scavenging mechanisms to maintain the redox balance. Hemopexins constitute one of these mechanisms preventing heme-associated oxidative stress in animals, fungi, and plants. Pisum sativum ENDOTHECIUM 1 (PsEND1) is a pea anther-specific gene that encodes a protein containing four hemopexin domains. We report the functional characterization of PsEND1 and the identification in its promoter region of cis-regulatory elements that are essential for the specific expression in anthers. PsEND1 promoter deletion analysis revealed that a putative CArG-like regulatory motif is necessary to confer promoter activity in developing anthers. Our data suggest that PsEND1 might be a hemopexin regulated by a MADS-box protein. PsEND1 gene silencing in pea, and its overexpression in heterologous systems, result in similar defects in the anthers consisting of precocious tapetum degradation and the impairment of pollen development. Such alterations were associated to the production of superoxide anion and altered activity of ROS-scavenging enzymes. Our findings demonstrate that PsEND1 is essential for pollen development by modulating ROS levels during the differentiation of the anther tissues surrounding the microsporocytes.

17.
Science ; 373(6551): 192-197, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244409

RESUMO

Throughout development, plant meristems regularly produce organs in defined spiral, opposite, or whorl patterns. Cauliflowers present an unusual organ arrangement with a multitude of spirals nested over a wide range of scales. How such a fractal, self-similar organization emerges from developmental mechanisms has remained elusive. Combining experimental analyses in an Arabidopsis thaliana cauliflower-like mutant with modeling, we found that curd self-similarity arises because the meristems fail to form flowers but keep the "memory" of their transient passage in a floral state. Additional mutations affecting meristem growth can induce the production of conical structures reminiscent of the conspicuous fractal Romanesco shape. This study reveals how fractal-like forms may emerge from the combination of key, defined perturbations of floral developmental programs and growth dynamics.


Assuntos
Arabidopsis/anatomia & histologia , Arabidopsis/genética , Brassica/anatomia & histologia , Brassica/genética , Redes Reguladoras de Genes , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassica/crescimento & desenvolvimento , Flores/anatomia & histologia , Flores/genética , Flores/crescimento & desenvolvimento , Fractais , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Inflorescência/anatomia & histologia , Inflorescência/genética , Inflorescência/crescimento & desenvolvimento , Meristema/crescimento & desenvolvimento , Modelos Biológicos , Mutação , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transcriptoma
18.
Front Plant Sci ; 12: 642879, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33815449

RESUMO

The specified floral meristem will develop a pre-established number of floral organs and, thus, terminate the floral meristematic cells. The floral meristematic pool of cells is controlled, among some others, by WUSCHEL (WUS) and AGAMOUS (AG) transcription factors (TFs). Here, we demonstrate that the SCI1 (Stigma/style cell-cycle inhibitor 1) gene, a cell proliferation regulator, starts to be expressed since the floral meristem specification of Nicotiana tabacum and is expressed in all floral meristematic cells. Its expression is higher in the floral meristem and the organs being specified, and then it decreases from outside to inside whorls when the organs are differentiating. SCI1 is co-expressed with N. tabacum WUSCHEL (NtWUS) in the floral meristem and the whorl primordia at very early developmental stages. Later in development, SCI1 is co-expressed with NAG1 (N. tabacum AG) in the floral meristem and specialized tissues of the pistil. In silico analyses identified cis-regulatory elements for these TFs in the SCI1 genomic sequence. Yeast one-hybrid and electrophoresis mobility shift assay demonstrated that both TFs interact with the SCI1 promoter sequence. Additionally, the luciferase activity assay showed that NAG1 clearly activates SCI1 expression, while NtWUS could not do so. Taken together, our results suggest that during floral development, the spatiotemporal regulation of SCI1 by NtWUS and NAG1 may result in the maintenance or termination of proliferative cells in the floral meristem, respectively.

19.
Transplant Proc ; 52(2): 596-598, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32061425

RESUMO

Anastomotic airway complications after lung transplantation affect up to 20% of patients. Bronchial stenosis is the most frequent complication, while dehiscence of bronchial anastomosis is a rarely seen complication, with report incidences between 1% and 10%. Despite its low incidence, dehiscence of bronchial anastomoses remains a disastrous complication in the posttransplantation period without a well-established management protocol. We present a challenging case of complete bronchial dehiscence after unilateral lung transplantation in a patient with interstitial lung fibrosis (ILF) that occurred on postoperative day 10. The dehiscence was diagnosed early and the patient's status was stable for repeat thoracotomy, therefore, an early surgical approach was preferable to conservative management or bronchoscopy. Aggressive early surgical management in a stable patient allows for complete debridement with removal of the detritus that impedes correct anastomosis healing and permits the removal of microbial vegetations with successful results.


Assuntos
Brônquios/cirurgia , Transplante de Pulmão/efeitos adversos , Complicações Pós-Operatórias/cirurgia , Deiscência da Ferida Operatória/cirurgia , Anastomose Cirúrgica/efeitos adversos , Brônquios/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Deiscência da Ferida Operatória/etiologia
20.
Transplant Proc ; 52(2): 584-586, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32037063

RESUMO

Post-thoracotomy wound dehiscence after a lung transplant carries with it morbidity in the postoperative period. While this complication has been widely reported in the literature after a clamshell incision, the thoracotomy dehiscence's surgical solution has not received much emphasis. We present an original technical solution to deal with this complication, performed successfully in a 62-year-old woman diagnosed as having idiopathic pulmonary hemosiderosis after a single lung transplant. This surgical treatment consists of necrotic rib tissue removal, pleural effusion drainage, pulmonary adhesion removal, and chest wall defect reparation with bioabsorbable mesh. This operative technique results safe and effective for thoracotomy dehiscence reparation.


Assuntos
Transplante de Pulmão/efeitos adversos , Procedimentos de Cirurgia Plástica/métodos , Deiscência da Ferida Operatória/etiologia , Deiscência da Ferida Operatória/cirurgia , Toracotomia/efeitos adversos , Feminino , Humanos , Transplante de Pulmão/métodos , Pessoa de Meia-Idade , Próteses e Implantes , Procedimentos de Cirurgia Plástica/instrumentação , Toracotomia/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA