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1.
Plant J ; 115(6): 1699-1715, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37300848

RESUMEN

Plant architecture, lodging resistance, and yield are closely associated with height. In this paper, we report the identification and characterization of two allelic EMS-induced mutants of Zea mays, xyl-1, and xyl-2 that display dwarf phenotypes. The mutated gene, ZmXYL, encodes an α-xylosidase which functions in releasing xylosyl residue from a ß-1,4-linked glucan chain. Total α-xylosidase activity in the two alleles is significantly decreased compared to wild-type plants. Loss-of-function mutants of ZmXYL resulted in a decreased xylose content, an increased XXXG content in xyloglucan (XyG), and a reduced auxin content. We show that auxin has an antagonistic effect with XXXG in promoting cell divisions within mesocotyl tissue. xyl-1 and xyl-2 were less sensitive to IAA compared to B73. Based on our study, a model is proposed that places XXXG, an oligosaccharide derived from XyG and the substrate of ZmXYL, as having a negative impact on auxin homeostasis resulting in the dwarf phenotypes of the xyl mutants. Our results provide a insight into the roles of oligosaccharides released from plant cell walls as signals in mediating plant growth and development.


Asunto(s)
Xilosidasas , Zea mays , Zea mays/genética , Ácidos Indolacéticos , Oligosacáridos/química , Plantas/genética
2.
Plant Physiol ; 193(3): 1834-1848, 2023 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-37403650

RESUMEN

Plant metaxylem vessels provide physical support to promote upright growth and the transport of water and nutrients. A detailed characterization of the molecular network controlling metaxylem development is lacking. However, knowledge of the events that regulate metaxylem development could contribute to the development of germplasm with improved yield. In this paper, we screened an EMS-induced B73 mutant library, which covers 92% of maize (Zea mays) genes, to identify drought-sensitive phenotypes. Three mutants were identified, named iqd27-1, iqd27-2, and iqd27-3, and genetic crosses showed that they were allelic to each other. The causal gene in these 3 mutants encodes the IQ domain-containing protein ZmIQD27. Our study showed that defective metaxylem vessel development likely causes the drought sensitivity and abnormal water transport phenotypes in the iqd27 mutants. ZmIQD27 was expressed in the root meristematic zone where secondary cell wall deposition is initiated, and loss-of-function iqd27 mutants exhibited a microtubular arrangement disorder. We propose that association of functional ZmIQD27 with microtubules is essential for correct targeted deposition of the building blocks for secondary cell wall development in maize.


Asunto(s)
Meristema , Zea mays , Zea mays/metabolismo , Plantones/genética , Sequías , Agua/metabolismo
3.
J Infect Dis ; 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-38134313

RESUMEN

BACKGROUND: Cabotegravir + rilpivirine (CAB + RPV) is a guideline-recommended long-acting (LA) injectable regimen for the maintenance of HIV-1 virologic suppression. This post hoc analysis summarizes CAB + RPV LA results by baseline body mass index (BMI) category among Phase 3/3b trial participants. METHODS: Data from CAB + RPV-naive participants receiving every 4 or 8 week dosing in FLAIR, ATLAS, and ATLAS-2 M were pooled through Week (W) 48. Data beyond W48 were summarized by study (FLAIR through W96 and ATLAS-2 M through W152). HIV 1 RNA <50 and ≥50 copies/mL, confirmed virologic failure (CVF; two consecutive HIV-1 RNA ≥200 copies/mL), safety and tolerability, and plasma CAB and RPV trough concentrations were evaluated by baseline BMI (<30 kg/m2 [lower]; ≥ 30 kg/m2 [higher]). RESULTS: Among 1245 CAB + RPV LA participants, 213 (17%) had a baseline BMI ≥30 kg/m2. At W48, 92% vs. 93% of participants with lower vs. higher BMI had HIV-1 RNA <50 copies/mL, respectively. Including data beyond W48, 18 participants had CVF; those in the higher BMI group (n = 8) all had at least one other baseline factor associated with CVF (archived RPV resistance-associated mutations or HIV 1 subtype A6/A1). Safety and pharmacokinetic profiles were comparable between BMI categories. CONCLUSION: CAB + RPV LA was efficacious and well tolerated, regardless of baseline BMI category.Main point summary: CAB + RPV LA is effective in the maintenance of HIV-1 virologic suppression in adults regardless of BMI category, with longer-length needles (≥2 inches) recommend for those with BMI ≥30 kg/m2 to accommodate individual body habitus and ensure appropriate administration.

4.
Plant Biotechnol J ; 20(2): 297-309, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34543503

RESUMEN

ERECTA PANICLE 3 (EP3) and ORYZA SATIVA F-BOX KELCH 1 (OsFBK1) proteins share 57% and 54% sequence identity with the Arabidopsis F-box protein HAWAIIAN SKIRT (HWS). Previously we showed that EP3 is a functional orthologue of HWS. Here we demonstrate that OsFBK1 is another functional orthologue of HWS and show the complexity of interaction between EP3 and OsFBK1 genes at different developmental stages of the plant. qRT-PCR expression analyses and studies of EP3-GFP and OsFBK1-RFP promoter reporter lines demonstrate that although EP3 and OsFBK1 expression can be detected in the same tissues some cells exclusively express EP3 or OsFBK1 whilst others co-express both genes. Loss, reduction or gain-of-function lines for EP3 and OsFBK1, show that EP3 and OsFBK1 affect plant architecture, organ size, floral organ number and size, floral morphology, pollen viability, grain size and weight. We have identified the putative orthologue genes of the rice microRNA pathway for ORYZA SATIVA DAWDLE (OsDDL) and ORYZA SATIVA SERRATE (OsSE), and demonstrated that EP3 and OsFBK1 affect their transcript levels as well as those of CROWN ROOT DEFECT 1/ORYZA SATIVA Exportin-5 HASTY (CRD1/OsHST), ORYZA SATIVA DICER-LIKE 1 (OsDCL) and ORYZA SATIVA WEAVY LEAF1 (OsWAF1). We show that EP3 affects OsPri-MIR164, OsNAM1 and OsNAC1 transcript levels. OsNAC1 transcripts are modified by OsFBK1, suggesting two independent regulatory pathways, one via EP3 and OsMIR164 and the other via OsFBK1. Our data propose that EP3 and OsFBK1 conjointly play similar roles in rice to how HWS does in Arabidopsis.


Asunto(s)
Arabidopsis , MicroARNs , Oryza , Arabidopsis/metabolismo , Flores , Regulación de la Expresión Génica de las Plantas/genética , MicroARNs/genética , MicroARNs/metabolismo , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo
5.
New Phytol ; 235(3): 885-897, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35491444

RESUMEN

Salicylic acid (SA) is a key phytohormone regulating plant immunity. Although the transcriptional regulation of SA biosynthesis has been well-studied, its post-translational regulation is largely unknown. We report that a Kelch repeats-containing F-box (KFB) protein, SMALL AND GLOSSY LEAVES 1 (SAGL1), negatively influences SA biosynthesis in Arabidopsis thaliana by mediating the proteolytic turnover of SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1), a master transcription factor that directly drives SA biosynthesis during immunity. Loss of SAGL1 resulted in characteristic growth inhibition. Combining metabolomic, transcriptional and phenotypic analyses, we found that SAGL1 represses SA biosynthesis and SA-mediated immune activation. Genetic crosses to mutants that are deficient in SA biosynthesis blocked the SA overaccumulation in sagl1 and rescued its growth. Biochemical and proteomic analysis identified that SAGL1 interacts with SARD1 and promotes the degradation of SARD1 in a proteasome-dependent manner. These results unravelled a critical role of KFB protein SAGL1 in maintaining SA homeostasis via controlling SARD1 stability.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteínas F-Box , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas F-Box/genética , Regulación de la Expresión Génica de las Plantas , Inmunidad de la Planta , Proteómica , Ácido Salicílico/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
6.
Plant Cell Environ ; 44(5): 1379-1398, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33554357

RESUMEN

With diverse genetic backgrounds, soybean landraces are valuable resource for breeding programs. Herein, we apply multi-omic approaches to extensively characterize the molecular basis of drought tolerance in the soybean landrace LX. Initial screens established that LX performed better with PEG6000 treatment than control cultivars. LX germinated better than William 82 under drought conditions and accumulated more anthocyanin and flavonoids. Untargeted mass spectrometry in combination with transcriptomic analyses revealed the chemical diversity and genetic basis underlying the overall performance of LX landrace. Under control and drought conditions, significant differences in the expression of a suite of secondary metabolism genes, particularly those involved in the general phenylpropanoid pathway and flavonoid but not lignin biosynthesis, were seen in LX and William 82. The expression of these genes correlated with the corresponding metabolites in LX plants. Further correlation analysis between metabolites and transcripts identified pathway structural genes and transcription factors likely are responsible for the LX agronomic traits. The activities of some key biosynthetic genes or regulators were confirmed through heterologous expression in transgenic Arabidopsis and hairy root transformation in soybean. We propose a regulatory mechanism based on flavonoid secondary metabolism and adaptive traits of this landrace which could be of relevance to cultivated soybean.


Asunto(s)
Sequías , Genómica , Glycine max/fisiología , Carácter Cuantitativo Heredable , Antocianinas/biosíntesis , Flavonoides/biosíntesis , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Germinación/fisiología , Metaboloma/genética , Metabolómica , Fenotipo , Propanoles/metabolismo , Reproducibilidad de los Resultados , Metabolismo Secundario/genética , Glycine max/genética , Estrés Fisiológico/genética , Factores de Transcripción/metabolismo , Transcriptoma/genética
7.
BMC Genomics ; 20(1): 993, 2019 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-31856713

RESUMEN

BACKGROUND: F-box proteins are substrate-recognition components of the Skp1-Rbx1-Cul1-F-box protein (SCF) ubiquitin ligases. By selectively targeting the key regulatory proteins or enzymes for ubiquitination and 26S proteasome mediated degradation, F-box proteins play diverse roles in plant growth/development and in the responses of plants to both environmental and endogenous signals. Studies of F-box proteins from the model plant Arabidopsis and from many additional plant species have demonstrated that they belong to a super gene family, and function across almost all aspects of the plant life cycle. However, systematic exploration of F-box family genes in the important fiber crop cotton (Gossypium hirsutum) has not been previously performed. The genome-wide analysis of the cotton F-box gene family is now possible thanks to the completion of several cotton genome sequencing projects. RESULTS: In current study, we first conducted a genome-wide investigation of cotton F-box family genes by reference to the published F-box protein sequences from other plant species. 592 F-box protein encoding genes were identified in the Gossypium hirsutume acc.TM-1 genome and, subsequently, we were able to present their gene structures, chromosomal locations, syntenic relationships with their parent species. In addition, duplication modes analysis showed that cotton F-box genes were distributed to 26 chromosomes, with the maximum number of genes being detected on chromosome 5. Although the WGD (whole-genome duplication) mode seems play a dominant role during cotton F-box gene expansion process, other duplication modes including TD (tandem duplication), PD (proximal duplication), and TRD (transposed duplication) also contribute significantly to the evolutionary expansion of cotton F-box genes. Collectively, these bioinformatic analysis suggest possible evolutionary forces underlying F-box gene diversification. Additionally, we also conducted analyses of gene ontology, and expression profiles in silico, allowing identification of F-box gene members potentially involved in hormone signal transduction. CONCLUSION: The results of this study provide first insights into the Gossypium hirsutum F-box gene family, which lays the foundation for future studies of functionality, particularly those involving F-box protein family members that play a role in hormone signal transduction.


Asunto(s)
Proteínas F-Box/genética , Gossypium/genética , Proteínas de Plantas/genética , Proteínas F-Box/clasificación , Proteínas F-Box/metabolismo , Duplicación de Gen , Ontología de Genes , Genoma de Planta , Gossypium/metabolismo , Familia de Multigenes , Reguladores del Crecimiento de las Plantas/fisiología , Proteínas de Plantas/clasificación , Proteínas de Plantas/metabolismo , Proteínas Ligasas SKP Cullina F-box/fisiología , Transducción de Señal
8.
J Exp Bot ; 70(5): 1461-1467, 2019 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-30726930

RESUMEN

Abscission is a developmental process with important implications for agricultural practices. Ethylene has long been considered as a key regulator of the abscission process. The existence of an ethylene-independent abscission pathway, controlled by the complex of INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) peptide and the HAESA (HAE) and HAESA-like2 (HSL2) kinases, has been proposed, based mainly on observations that organ abscission in ethylene-insensitive mutants was delayed but not inhibited. A recent review on plant organ abscission signaling highlighted the IDA-HAE-HSL2 components as the regulators of organ abscission, while the role of auxin and ethylene in this process was hardly addressed. After a careful analysis of the relevant abscission literature, we propose that the IDA-HAE-HSL2 pathway is essential for the final stages of organ abscission, while ethylene plays a major role in its initiation and progression. We discuss the view that the IDA-HAE-HSL2 pathway is ethylene independent, and present recent evidence showing that ethylene activates the IDA-HAE-HSL2 complex. We conclude that the ability of an organ to abscise is tightly linked to cell turgidity in the abscission zone, and suggest that lack of cell turgidity might contribute to the failure of floral organ abscission in the ida mutants.


Asunto(s)
Etilenos/metabolismo , Flores/crecimiento & desarrollo , Desarrollo de la Planta , Plantas/metabolismo , Transducción de Señal
9.
J Exp Bot ; 66(5): 1543-52, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25582452

RESUMEN

The ERECT PANICLE 3 gene of rice encodes a peptide that exhibits more than 50% sequence identity with the Arabidopsis F-box protein HAWAIIAN SKIRT (HWS). Ectopic expression of the Os02g15950 coding sequence, driven by the HWS (At3g61950) promoter, rescued the hws-1 flower phenotype in Arabidopsis confirming that EP3 is a functional orthologue of HWS. In addition to displaying an erect inflorescence phenotype, loss-of-function mutants of Os02g15950 exhibited a decrease in leaf photosynthetic capacity and stomatal conductance. Analysis of a range of physiological and anatomical features related to leaf photosynthesis revealed no alteration in Rubisco content and no notable changes in mesophyll size or arrangement. However, both ep3 mutant plants and transgenic lines that have a T-DNA insertion within the Os02g15950 (EP3) gene exhibit smaller stomatal guard cells compared with their wild-type controls. This anatomical characteristic may account for the observed decrease in leaf photosynthesis and provides evidence that EP3 plays a role in regulating stomatal guard cell development.


Asunto(s)
Oryza/metabolismo , Proteínas de Plantas/genética , Estomas de Plantas/química , Estomas de Plantas/citología , Mutación , Oryza/química , Oryza/citología , Oryza/genética , Fotosíntesis , Proteínas de Plantas/metabolismo , Estomas de Plantas/genética , Estomas de Plantas/metabolismo
10.
Plant Physiol ; 162(1): 96-106, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23509178

RESUMEN

A number of novel strategies were employed to examine the role of indoleacetic acid (IAA) in regulating floral organ abscission in Arabidopsis (Arabidopsis thaliana). Analysis of auxin influx facilitator expression in ß-glucuronidase reporter plants revealed that AUXIN RESISTANT1, LIKE AUX1, and LAX3 were specifically up-regulated at the site of floral organ shedding. Flowers from mutants where individual family members were down-regulated exhibited a reduction in the force necessary to bring about petal separation; however, the effect was not additive in double or quadruple mutants. Using the promoter of a polygalacturonase (At2g41850), active primarily in cells undergoing separation, to drive expression of the bacterial genes iaaL and iaaM, we have shown that it is possible to manipulate auxin activity specifically within the floral organ abscission zone (AZ). Analysis of petal breakstrength reveals that if IAA AZ levels are reduced, shedding takes place prematurely, while if they are enhanced, organ loss is delayed. The At2g41850 promoter was also used to transactivate the gain-of-function AXR3-1 gene in order to disrupt auxin signaling specifically within the floral organ AZ cells. Flowers from transactivated lines failed to shed their sepals, petals, and anthers during pod expansion and maturity, and these organs frequently remained attached to the plant even after silique desiccation and dehiscence had taken place. These observations support a key role for IAA in the regulation of abscission in planta and reveal, to our knowledge for the first time, a requirement for a functional IAA signaling pathway in AZ cells for organ shedding to take place.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/fisiología , Ácidos Indolacéticos/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/metabolismo , Flores/fisiología , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Glucuronidasa/genética , Glucuronidasa/metabolismo , Fenotipo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Poligalacturonasa/genética , Poligalacturonasa/metabolismo , Transducción de Señal/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
11.
Indian J Plast Surg ; 47(1): 56-60, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24987205

RESUMEN

INTRODUCTION: Gynaecomastia is a common problem in the male population with a reported prevalence of up to 36%. Various treatment techniques have been described but none have gained universal acceptance. We reviewed all gynaecomastia patients operated on by one consultant over a 7-year period to assess the morbidity and complication rates associated with the procedure. MATERIALS AND METHODS: Clinical notes and outpatient records of all patients who underwent gynaecomastia correction at University Hospital North Staffordshire between 01/10/2001 to 01/10/2009 were retrospectively reviewed. A modified version of the Breast Evaluation Questionnaire was used to assess patients satisfaction with the procedure. RESULTS: Twenty-nine patients and a total of 53 breasts were operated on during the study period. Patients underwent either liposuction alone (6 breasts - 11.3%), excision alone (37 breasts - 69.8%) or both excision and liposuction (10 breasts - 18.9%). Twelve operated breasts (22.6%) experienced some form of complication. Minor complications included seroma (2 patients), superficial wound dehiscence (2 patients) and minor bleeding not requiring theatre (3 patients). Two patients developed haematomas requiring evacuation in theatre. No cases of wound infection, major wound dehiscence or revision surgery were encountered. Twenty-six patients (89.7%) returned the patient satisfaction questionnaire. Patients scored an average 4.12 with regards comfort of their chest in different settings, 3.98 with regards chest appearance in different settings, and 4.22 with regards satisfaction levels for themselves and their partner/family. Overall complication rate was 22.6%. Grade III patients experienced the highest complication rate (35.7%), followed by grade II (22.7%) and grade I (17.6%). Overall complication rates among the excision only group was the highest (29.8%) followed by the liposuction only group (16.7%) and the liposuction and excision group (10.0%). There were high satisfaction rates amongst both patients and surgeon. Eleven patients (37.9%) had their outcome classified as 'excellent' by the operating surgeon, 16 patients (55.2%) as 'good', 1 (3.4%) as 'satisfactory' and 1(3.4%) as 'poor'. CONCLUSION: Gynaecomastia is a complex condition which poses a significant challenge to the plastic surgeon. Despite the possible complications our case series demonstrates that outcomes of operative correction can be favourable and yield high levels of satisfaction from both patient and surgeon.

12.
J Pediatr Rehabil Med ; 17(1): 125-129, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37522227

RESUMEN

This report describes a 15-year-old female with known spastic and dystonic quadriplegic cerebral palsy (CP), Gross Motor Function Classification System IV, and obstructive sleep apnea (OSA). She experienced decreased apneic episodes after receiving onabotulinumtoxin A (BoNT-A) injections for the treatment of oromandibular dystonia (OMD). After her OSA diagnosis, she initially received injections to the bilateral masseter and temporalis muscles with no effect on the frequency of nightly apneic episodes. Subsequently, the bilateral lateral pterygoid muscles were added and she was later noted to have fewer apneic episodes overnight. This case report describes the use of BoNT-A in the muscles of mastication for management of OMD and the ensuing improvement in OSA in a teenager with CP.


Asunto(s)
Toxinas Botulínicas Tipo A , Parálisis Cerebral , Distonía , Trastornos Distónicos , Fármacos Neuromusculares , Apnea Obstructiva del Sueño , Femenino , Adolescente , Humanos , Toxinas Botulínicas Tipo A/uso terapéutico , Distonía/complicaciones , Distonía/tratamiento farmacológico , Parálisis Cerebral/complicaciones , Parálisis Cerebral/tratamiento farmacológico , Fármacos Neuromusculares/uso terapéutico
13.
Pediatr Neurol ; 154: 15-19, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38447508

RESUMEN

BACKGROUND: Postoperative pediatric cerebellar mutism syndrome (CMS) may occur following a process affecting the posterior cranial fossa. Recent evidence demonstrates disabling and potentially lasting motor components of this syndrome, including ataxia, hemiparesis, and oculomotor dysfunction. These impairments may contribute to vestibular deficits. METHODS: This case series contributes data to quantify vestibular dysfunction in postoperative CMS. The pair consisted of one female and one male. RESULTS: Vestibular testing demonstrated both peripheral and central dysfunction. CONCLUSIONS: Given these findings, a thorough vestibular assessment may be indicated as part of a comprehensive evaluation following a postoperative CMS diagnosis. Further research is needed to understand the pathophysiology, treatment, and long-term outcomes of postoperative pediatric CMS.


Asunto(s)
Enfermedades Cerebelosas , Neoplasias Cerebelosas , Mutismo , Niño , Humanos , Masculino , Femenino , Mutismo/diagnóstico , Mutismo/etiología , Neoplasias Cerebelosas/cirugía , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Enfermedades Cerebelosas/diagnóstico , Enfermedades Cerebelosas/etiología , Fosa Craneal Posterior , Síndrome
14.
Phys Sportsmed ; : 1-9, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38648009

RESUMEN

OBJECTIVE: To understand factors associated with missed academic time after concussion to improve support for patients. Our goal was to assess patient-specific predictors of total school time lost after pediatric/adolescent concussion. STUDY DESIGN: We performed a prospective cohort study of children and adolescents (8-18 years of age) seen within 14 days of concussion from seven pediatric medical centers across the United States. We collected outcomes via the Concussion Learning Assessment & School Survey (CLASS) and constructed a multivariable predictive model evaluating patient factors associated with school time loss. RESULTS: 167 patients participated (mean age = 14.5 ± 2.2 years; 46% female). Patients were assessed initially at 5.0 ± 3.0 days post-injury and had a final follow-up assessment 24.5 ± 20.0 days post-concussion. Participants missed a median of 2 days of school (IQR = 0.5-4), and 21% reported their grades dropped after concussion. Higher initial symptom severity rating (ß = 0.06, 95% CI = 0.03-0.08, p < 0.001) and perception of grades dropping after concussion (ß = 1.37, 95% CI = 0.28-2.45, p = 0.01) were significantly associated with more days of school time missed after concussion. Those who reported their grades dropping reported missing significantly more school (mean = 5.0, SD = 4.7 days missed of school) than those who reported their grades did not drop (mean = 2.2, SD = 2.6 days missed of school; p < 0.001; Cohen's d = 0.87). CONCLUSIONS: Children and adolescents reported missing a median of 2 days of school following concussion, and more missed school time after a concussion was associated with more severe concussion symptoms and perception of grades dropping. These findings may support recommendations for minimal delays in return-to-learn after concussion.

15.
Plant Physiol ; 160(3): 1342-56, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22992509

RESUMEN

Abscission is the consequence of a specialized layer of cells undergoing a complex series of molecular and biochemical events. Analysis of the specific molecular changes associated with abscission is hampered by contamination from neighboring nonseparating tissues. Moreover, studies of abscission frequently involve the examination of events that take place in isolated segments of tissue exposed to nonphysiological concentrations of ethylene or indole-3-acetic acid for protracted periods (more than 24 h) of time. To resolve these problems, we have adopted the use of a transgenic line of Arabidopsis (Arabidopsis thaliana) where the promoter of an abscission-specific polygalacturonase gene (At2g41850/ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE2) has been fused to a green fluorescent protein reporter. RNA was extracted from green fluorescent protein-tagged cells, released from abscising floral organs, and used to generate a complementary DNA library. This library was used to probe a microarray, and a population of abscission-related transcripts was studied in detail. Seven novel abscission-related genes were identified, four of which encode proteins of unknown function. Reverse transcription-polymerase chain reaction analyses and promoter fusions to the ß-glucuronidase reporter gene confirmed the expression of these genes in the abscission zone and revealed other places of expression during seedling development. Three of these genes were studied further by crossing reporter lines to the abscission mutants inflorescence deficient in abscission (ida) and blade-on-petiole1 (bop1)/bop2 and an IDA-overexpressing line. Phenotypic analysis of an At3g14380 transfer DNA insertion line indicates that this gene plays a functional role in floral organ shedding. This strategy has enabled us to uncover new genes involved in abscission, and their possible contribution to the process is discussed.


Asunto(s)
Arabidopsis/crecimiento & desarrollo , Fisiología/métodos , Arabidopsis/citología , Arabidopsis/genética , Flores/genética , Flores/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas , Biblioteca de Genes , Genes de Plantas/genética , Genes Reporteros , Glucuronidasa/metabolismo , Proteínas Fluorescentes Verdes/metabolismo , Mutación/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Especificidad de Órganos/genética , Células Vegetales/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Tiempo
16.
J Exp Bot ; 63(9): 3391-400, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22291133

RESUMEN

The distribution of nutrients and assimilates in different organs and tissues is in a constant state of flux throughout the growth and development of a plant. At key stages during the life cycle profound changes occur, and perhaps one of the most critical of these is during seed filling. By restricting the competition for reserves in Arabidopsis plants, the ability to manipulate seed size, seed weight, or seed content has been explored. Removal of secondary inflorescences and lateral branches resulted in a stimulation of elongation of the primary inflorescence and an increase in the distance between siliques. The pruning treatment also led to the development of longer and larger siliques that contained fewer, bigger seeds. This seems to be a consequence of a reduction in the number of ovules that develop and an increase in the fatty acid content of the seeds that mature. The data show that shoot architecture could have a substantial impact on the partitioning of reserves between vegetative and reproductive tissues and could be an important trait for selection in rapid phenotyping screens to optimize crop performance.


Asunto(s)
Desarrollo de la Planta , Plantas/metabolismo , Cruzamiento , Productos Agrícolas/crecimiento & desarrollo , Productos Agrícolas/metabolismo , Semillas/crecimiento & desarrollo , Semillas/metabolismo
17.
Ann Bot ; 110(2): 511-9, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22362666

RESUMEN

BACKGROUND AND AIMS: We sought to explore the interactions between roots and soil without disturbance and in four dimensions (i.e. 3-D plus time) using X-ray micro-computed tomography. METHODS: The roots of tomato Solanum lycopersicum 'Ailsa Craig' plants were visualized in undisturbed soil columns for 10 consecutive days to measure the effect of soil compaction on selected root traits including elongation rate. Treatments included bulk density (1.2 vs. 1.6 g cm(-3)) and soil type (loamy sand vs. clay loam). KEY RESULTS: Plants grown at the higher soil bulk density exploited smaller soil volumes (P < 0.05) and exhibited reductions in root surface area (P < 0.001), total root volume (P < 0.001) and total root length (P < 0.05), but had a greater mean root diameter (P < 0.05) than at low soil bulk density. Swelling of the root tip area was observed in compacted soil (P < 0.05) and the tortuosity of the root path was also greater (P < 0.01). Root elongation rates varied greatly during the 10-d observation period (P < 0.001), increasing to a maximum at day 2 before decreasing to a minimum at day 4. The emergence of lateral roots occurred later in plants grown in compacted soil (P < 0.01). Novel rooting characteristics (convex hull volume, centroid and maximum width), measured by image analysis, were successfully employed to discriminate treatment effects. The root systems of plants grown in compacted soil had smaller convex hull volumes (P < 0.05), a higher centre of mass (P < 0.05) and a smaller maximum width than roots grown in uncompacted soil. CONCLUSIONS: Soil compaction adversely affects root system architecture, influencing resource capture by limiting the volume of soil explored. Lateral roots formed later in plants grown in compacted soil and total root length and surface area were reduced. Root diameter was increased and swelling of the root tip occurred in compacted soil.


Asunto(s)
Meristema/citología , Meristema/crecimiento & desarrollo , Suelo , Solanum lycopersicum/citología , Solanum lycopersicum/crecimiento & desarrollo , Estrés Mecánico , Adaptación Fisiológica , Suelo/química , Microtomografía por Rayos X
18.
Sci Rep ; 12(1): 14610, 2022 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-36028657

RESUMEN

Modeling of biological domains and simulation of biophysical processes occurring in them can help inform medical procedures. However, when considering complex domains such as large regions of the human body, the complexities of blood vessel branching and variation of blood vessel dimensions present a major modeling challenge. Here, we present a Voxelized Multi-Physics Simulation (VoM-PhyS) framework to simulate coupled heat transfer and fluid flow using a multi-scale voxel mesh on a biological domain obtained. In this framework, flow in larger blood vessels is modeled using the Hagen-Poiseuille equation for a one-dimensional flow coupled with a three-dimensional two-compartment porous media model for capillary circulation in tissue. The Dirac distribution function is used as Sphere of Influence (SoI) parameter to couple the one-dimensional and three-dimensional flow. This blood flow system is coupled with a heat transfer solver to provide a complete thermo-physiological simulation. The framework is demonstrated on a frog tongue and further analysis is conducted to study the effect of convective heat exchange between blood vessels and tissue, and the effect of SoI on simulation results.


Asunto(s)
Circulación Sanguínea/fisiología , Temperatura Corporal/fisiología , Cuerpo Humano , Modelos Biológicos , Capilares , Simulación por Computador , Calor , Humanos , Imagenología Tridimensional
19.
AIDS ; 36(2): 195-203, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-34652287

RESUMEN

OBJECTIVES: Long-acting formulations of cabotegravir (CAB) and rilpivirine (RPV) have demonstrated efficacy in Phase 3 studies. POLAR (NCT03639311) assessed antiviral activity and safety of CAB+RPV long-acting administered every 2 months (Q2M) in adults living with HIV-1 who previously received daily oral CAB+RPV in LATTE (NCT01641809). DESIGN: A Phase 2b, multicenter, open-label, rollover study. METHODS: LATTE participants with plasma HIV-1 RNA less than 50 copies/ml who completed at least 300 weeks on study were eligible. Participants elected to switch to either CAB+RPV long-acting Q2M or daily oral dolutegravir/RPV for maintenance of virologic suppression. The primary endpoint was the proportion of participants with HIV-1 RNA greater than or equal to 50 copies/ml at Month 12 (M12) per the Food and Drug Administration Snapshot algorithm. The incidence of confirmed virologic failure (CVF, two consecutive HIV-1 RNA measurements greater than or equal to 200 copies/ml), as well as safety, laboratory, and patient-reported outcomes (HIV Treatment Satisfaction and preference questionnaires) were also assessed. RESULTS: Of 97 participants enrolled, 90 chose to receive CAB+RPV long-acting and seven chose dolutegravir/RPV. At M12, no participant had HIV-1 RNA greater than or equal to 50 copies/ml or met the CVF criterion in either treatment group. No new safety signals were identified. Total treatment satisfaction was high at Baseline and remained stable through M12 across both treatment groups. Overall, 88% (n = 77/88) of long-acting arm participants preferred CAB+RPV long-acting to oral CAB+RPV. CONCLUSION: CAB+RPV long-acting maintained virologic suppression in participants who had previously received daily oral CAB+RPV for at least 5 years in LATTE, with a favorable safety profile. Most participants preferred CAB+RPV long-acting to their prior oral CAB+RPV regimen at M12.


Asunto(s)
Fármacos Anti-VIH , Infecciones por VIH , VIH-1 , Adulto , Fármacos Anti-VIH/uso terapéutico , Dicetopiperazinas , Infecciones por VIH/tratamiento farmacológico , VIH-1/genética , Humanos , Piridonas/uso terapéutico , Rilpivirina/uso terapéutico
20.
New Phytol ; 190(4): 838-853, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21507003

RESUMEN

Pods play a key role in encapsulating the developing seeds and protecting them from pests and pathogens. In addition to this protective function, it has been shown that the photosynthetically active pod wall contributes assimilates and nutrients to fuel seed growth. Recent work has revealed that signals originating from the pod may also act to coordinate grain filling and regulate the reallocation of reserves from damaged seeds to those that have retained viability. In this review we consider the evidence that pods can regulate seed growth and maturation, particularly in members of the Brassicaceae family, and explore how the timing and duration of pod development might be manipulated to enhance either the quantity of crop yield or its nutritional properties.


Asunto(s)
Brassicaceae/crecimiento & desarrollo , Reguladores del Crecimiento de las Plantas/metabolismo , Hojas de la Planta/metabolismo , Semillas/crecimiento & desarrollo , Transporte Biológico , Brassicaceae/metabolismo , Nitrógeno/metabolismo , Fotosíntesis , Hojas de la Planta/crecimiento & desarrollo , Semillas/ultraestructura
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