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1.
Physiol Plant ; 176(3): e14393, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38923555

RESUMO

An urgent challenge within crop production is to maintain productivity in a world plagued by climate change and its associated plant stresses, such as heat, drought and salinity. A key factor in this endeavor is to understand the dynamics of root suberization, and its role in plant-water relations and nutrient transport. This study focuses on the hypothesis that endodermal suberin, acts as a physical barrier preventing radial potassium (K) movement out of the vascular tissues during translocation. Previous attempts to experimentally support this idea have produced inconsistent results. We developed a Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) method, allowing us to visualize the distribution of mineral elements and track K movement. Cesium (Cs), dosed in optimized concentrations, was found to be an ideal tracer for K, due to its low background and similar chemical/biological properties. In suberin mutants of Arabidopsis thaliana, we observed a positive correlation between suberin levels and K translocation efficiency, indicating that suberin enhances the plant's ability to retain K within the vascular tissues during translocation from root to shoot. In barley (Hordeum vulgare), fully suberized seminal roots maintained higher K concentrations in the stele compared to younger, less suberized root zones. This suggests that suberization increases with root maturity, enhancing the barrier against K leakage. In nodal roots, suberin was scattered towards the phloem in mature root zones. Despite this incomplete suberization, nodal roots still restrict outward K movement, demonstrating that even partial suberin barriers can significantly reduce K loss. Our findings provide evidence that suberin is a barrier to K leakage during root-to-shoot translocation. This understanding is crucial to maintain crop productivity in the face of climate change.


Assuntos
Arabidopsis , Césio , Hordeum , Lipídeos , Raízes de Plantas , Potássio , Potássio/metabolismo , Raízes de Plantas/metabolismo , Arabidopsis/metabolismo , Arabidopsis/genética , Césio/metabolismo , Hordeum/metabolismo , Lipídeos/análise , Transporte Biológico
2.
New Phytol ; 242(3): 881-902, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38433319

RESUMO

In this review, we untangle the physiological key functions of the essential micronutrients and link them to the deficiency responses in plants. Knowledge of these responses at the mechanistic level, and the resulting deficiency symptoms, have improved over the last decade and it appears timely to review recent insights for each of them. A proper understanding of the links between function and symptom is indispensable for an accurate and timely identification of nutritional disorders, thereby informing the design and development of sustainable fertilization strategies. Similarly, improved knowledge of the molecular and physiological functions of micronutrients will be important for breeding programmes aiming to develop new crop genotypes with improved nutrient-use efficiency and resilience in the face of changing soil and climate conditions.


Assuntos
Micronutrientes , Melhoramento Vegetal , Plantas , Solo
3.
Arch Phys Med Rehabil ; 105(5): 835-842, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38350494

RESUMO

OBJECTIVE: To examine the cardiorespiratory effects of a forced-rate aerobic exercise (FE) intervention among individuals with chronic stroke compared with an upper extremity repetitive task practice (UE RTP) control group. DESIGN: Secondary analysis of data from a randomized controlled trial. SETTING: Research laboratory. PARTICIPANTS: Individuals with chronic stroke (N=60). INTERVENTIONS: Participants completed 24 sessions of FE followed by RTP (FE+RTP, N=30) or time matched RTP alone (N=30). The FE+RTP group was prescribed exercise at 60%-80% of heart rate reserve on a motorized stationary cycle ergometer for 45 minutes followed by 45 minutes of RTP. The control group completed 90 minutes of RTP. MAIN OUTCOME MEASURES: Metabolic exercise stress tests on a cycle ergometer were conducted at baseline and post-intervention. Outcomes included peak oxygen consumption (peak V̇o2) and anaerobic threshold (AT). RESULTS: Fifty participants completed the study intervention and pre/post stress tests. The FE+RTP group demonstrated significantly greater improvements in peak V̇o2 from 16.4±5.7 to 18.3±6.4 mL/min/kg compared with the RTP group (17.0±5.6 to 17.2±5.6 mL/min/kg, P=.020) and significantly greater improvements in AT from 10.3±2.8 to 11.5±3.6 mL/min/kg compared with the RTP group (10.8±3.9 to 10.4±3.2 mL/min/kg, P=.020). In analyzing predictors of post-intervention peak V̇o2, the multivariable linear regression model did not reveal a significant effect of age, sex, body mass index, or beta blocker usage. Similarly, bivariate linear regression models for the FE group only did not find any exercise variables (aerobic intensity, power, or cycling cadence) to be significant predictors of peak V̇o2. CONCLUSIONS: While the aerobic exercise intervention was integrated into rehabilitation to improve UE motor recovery, it was also effective in eliciting significant and meaningful improvements in cardiorespiratory fitness. This novel rehabilitation model may be an effective approach to improve motor and cardiorespiratory function in persons recovering from stroke.


Assuntos
Aptidão Cardiorrespiratória , Terapia por Exercício , Consumo de Oxigênio , Reabilitação do Acidente Vascular Cerebral , Humanos , Masculino , Reabilitação do Acidente Vascular Cerebral/métodos , Aptidão Cardiorrespiratória/fisiologia , Feminino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Terapia por Exercício/métodos , Idoso , Doença Crônica , Teste de Esforço , Limiar Anaeróbio/fisiologia , Ciclismo/fisiologia , Acidente Vascular Cerebral/fisiopatologia
4.
Environ Sci Technol ; 57(51): 21704-21714, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38079531

RESUMO

Foliar application of nutrient nanoparticles (NPs) is a promising strategy for improving fertilization efficiency in agriculture. Phloem translocation of NPs from leaves is required for efficient fertilization but is currently considered to be feasible only for NPs smaller than a cell wall pore size exclusion limit of <20 nm. Using mass spectrometry imaging, we provide here the first direct evidence for phloem localization and translocation of a larger (∼70 nm) fertilizer NP comprised of ZnO encapsulated in mesoporous SiO2 (ZnO@MSN) following foliar deposition. The Si content in the phloem tissue of the petiole connected to the dosed leaf was ∼10 times higher than in the xylem tissue, and ∼100 times higher than the phloem tissue of an untreated tomato plant petiole. Direct evidence of NPs in individual phloem cells has only previously been shown for smaller NPs introduced invasively in the plant. Furthermore, we show that uptake and translocation of the NPs can be enhanced by their application on the abaxial (lower) side of the leaf. Applying ZnO@MSN to the abaxial side of a single leaf resulted in a 56% higher uptake of Zn as well as higher translocation to the younger (upper) leaves and to the roots, than dosing the adaxial (top) side of a leaf. The higher abaxial uptake of NPs is in alignment with the higher stomatal density and lower density of mesophyll tissues on that side and has not been demonstrated before.


Assuntos
Nanopartículas , Solanum lycopersicum , Óxido de Zinco , Dióxido de Silício , Floema , Folhas de Planta , Zinco
5.
Case Rep Dermatol ; 15(1): 85-92, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37928338

RESUMO

Adverse reactions in tattooed skin during magnetic resonance imaging (MRI) are rare but well known. Previous reports describe sudden burning pain in tattooed skin, sometimes accompanied by mild erythema and oedema when entering MRI scanners. The pathophysiology remains unclear, but simple direct thermal heating can be excluded. It has been hypothesized that MRI-triggered torque and traction create neural sensations from magnetic pigment particles. However, this case enlightens yet another possible mechanism. We present a 35-year-old woman experiencing reoccurring stinging sensations in three decorative black tattoos just seconds after the initiation of the MRI. Single-blind tests with handheld power magnets or a dummy could reproduce painful subjective feelings in her tattooed skin. Similar events were provoked during re-evaluation with MRI. Surprisingly, chemical analyses and electron microscopy of skin samples revealed carbon black as the colouring agent - no iron-based solids were detected. Our case demonstrates that MRI tattoo reactions are not limited to magnetic contaminants alone. More distinct subgroups of MRI-induced reactions may occur. We hypothesize that radiofrequency induction of surface currents in black carbon particles adjacent to sensory axons in the dermis may lead to neurosensations.

6.
Am J Phys Med Rehabil ; 102(3): 275-283, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36730285

RESUMO

ABSTRACT: Increasing medical student exposure to physical medicine and rehabilitation is an important factor for future growth of the field. Therefore, it is important to determine which types of interventions during medical school have the greatest impact on medical students' decision to pursue a career in physical medicine and rehabilitation. The purpose of this study is to perform a scoping review of the current literature that has analyzed how different interventions and experiences impact medical school students' decision to pursue a career in physical medicine and rehabilitation. A systematic and comprehensive search strategy was implemented across five different journal databases and yielded 18 articles meeting the inclusion criteria. Most studies analyzing specific interventions looked only at presurvey and postsurvey comparisons of the immediate impact of the intervention on interest in physical medicine and rehabilitation, and few looked at longitudinal outcomes, such as match characteristics. The most frequently cited factor that was shown to positively impact interest in physical medicine and rehabilitation was early exposure. Participating in clinical rotations also had a positive impact but was most effective when combined with early exposure. This review highlights the need for national recommendations for integrating physical medicine and rehabilitation into all 4 yrs of medical education.


Assuntos
Educação Médica , Medicina , Medicina Física e Reabilitação , Estudantes de Medicina , Humanos , Escolha da Profissão
7.
Physiol Plant ; 174(4): e13761, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36004733

RESUMO

Foliar fertilization delivers essential nutrients directly to plant tissues, reducing excessive soil fertilizer applications that can lead to eutrophication following nutrient leaching. Foliar nutrient absorption is a dynamic process affected by leaf surface structure and composition, plant nutrient status, and ion physicochemical properties. We applied multiple methods to study the foliar absorption behaviors of manganese (Mn) and phosphorus (P) in nutrient-deficient spring barley (Hordeum vulgare) at two growth stages. Nutrient-specific chlorophyll a fluorescence assays were used to visualize leaf nutrient status, while laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to visualize foliar absorption pathways for P and Mn ions. Rapid Mn absorption was facilitated by a relatively thin cuticle with a low abundance of waxes and a higher stomatal density in Mn-deficient plants. Following absorption, Mn accumulated in epidermal cells and in the photosynthetically active mesophyll, enabling a fast (6 h) restoration of Mn-dependent photosynthetic processes. Conversely, P-deficient plants developed thicker cuticles and epidermal cell walls, which reduced the penetration of P across the leaf surface. Foliar-applied P accumulated in trichomes and fiber cells above leaf veins without reaching the mesophyll and, as a consequence, no restoration of P-dependent photosynthetic processes was observed. This study reveals new links between leaf surface morphology, foliar-applied ion absorption pathways, and the restoration of affected physiological processes in nutrient-deficient leaves. Understanding that ions may have different absorption pathways across the leaf surface is critical for the future development of efficient fertilization strategies for crops in nutrient-limited soils.


Assuntos
Hordeum , Manganês , Fósforo , Folhas de Planta , Clorofila A/análise , Hordeum/metabolismo , Íons/metabolismo , Manganês/metabolismo , Nutrientes/análise , Fósforo/metabolismo , Folhas de Planta/metabolismo , Solo
8.
Environ Pollut ; 307: 119530, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35636714

RESUMO

Nitric oxide (NO) and ethylene are both important signaling molecules which participate in numerous plant development processes and environmental stress resistance. Here, we investigate whether and how NO interacts with ethylene during the development of endodermal barriers that have major consequences for the apoplastic uptake of cadmium (Cd) in the hyperaccumulator Sedum alfredii. In response to Cd, an increased NO accumulation, while a decrease in ethylene production was observed in the roots of S. alfredii. Exogenous supplementation of NO donor SNP (sodium nitroprusside) decreased the ethylene production in roots, while NO scavenger cPTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) had the opposite effect. The exogenous addition of NO affected the ethylene production through regulating the expression of genes related to ethylene synthesis. However, upon exogenous ethylene addition, roots retained their NO accumulation. The abovementioned results suggest that ethylene is downstream of the NO signaling pathway in S. alfredii. Regardless of Cd, addition of SNP promoted the deposition of endodermal barriers via regulating the genes related to Casparian strips deposition and suberization. Correlation analyses indicate that NO positively modifies the formation of endodermal barriers via the NO-ethylene signaling pathway, Cd-induced NO accumulation interferes with the synthesis of ethylene, leading to a deposition of endodermal barriers in S. alfredii.


Assuntos
Sedum , Poluentes do Solo , Biodegradação Ambiental , Cádmio/metabolismo , Cádmio/toxicidade , Etilenos/metabolismo , Etilenos/farmacologia , Óxido Nítrico/metabolismo , Raízes de Plantas/metabolismo , Sedum/genética , Sedum/metabolismo , Poluentes do Solo/metabolismo
9.
Physiol Plant ; 174(1): e13624, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35023171

RESUMO

Increasing atmospheric CO2 concentration is expected to enhance the grain yield of C3 cereal plants, while at the same time reducing the concentrations of minerals and proteins. This will lead to a lower nutritional quality and increase global problems associated with micronutrient malnutrition. Among the barley grain storage proteins, the C-hordein fraction has the lowest abundance of sulfur (S) containing amino acids and is poorest in binding of zinc (Zn). In the present study, C-hordein-suppressed barley lines with reduced C-hordein content, obtained by use of antisense or RNAi technology, were investigated under ambient and elevated atmospheric CO2 concentration. Grains of the C-hordein-suppressed lines showed 50% increase in the concentrations of Zn and iron (Fe) in the core endosperm relative to the wild-type under both ambient and elevated atmospheric CO2 . Element distribution images obtained using laser ablation-inductively coupled plasma-mass spectrometry confirmed the enrichment of Fe and Zn in the core endosperm of the lines with modified storage protein composition. We conclude that modification of grain storage proteins may improve the nutritional value of cereal grain with respect to Zn and Fe under both normal and future conditions of elevated atmospheric CO2 .


Assuntos
Endosperma , Hordeum , Dióxido de Carbono/metabolismo , Grão Comestível/metabolismo , Hordeum/metabolismo , Ferro/metabolismo , Zinco/metabolismo
10.
Nat Commun ; 13(1): 365, 2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35042856

RESUMO

A central problem in any quantum theory of gravity is to explain the emergence of the classical spacetime geometry in some limit of a more fundamental, microscopic description of nature. The gauge/gravity-correspondence provides a framework in which this problem can, in principle, be addressed. This is a holographic correspondence which relates a supergravity theory in five-dimensional Anti-deSitter space to a strongly coupled superconformal gauge theory on its 4-dimensional flat Minkowski boundary. In particular, the classical geometry should therefore emerge from some quantum state of the dual gauge theory. Here we confirm this by showing how the classical metric emerges from a canonical state in the dual gauge theory. In particular, we obtain approximations to the Sasaki-Einstein metric underlying the supergravity geometry, in terms of an explicit integral formula involving the canonical quantum state in question. In the special case of toric quiver gauge theories we show that our results can be computationally simplified through a process of tropicalization.

11.
Lasers Surg Med ; 54(1): 170-181, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34859463

RESUMO

BACKGROUND AND OBJECTIVES: Current cancer immunotherapeutic treatment with PD-1 inhibitors is administered systemically. However, a local treatment strategy may be advantageous as it could provide targeted drug delivery as well as attenuate side effects seen with systemic treatments. For keratinocyte cancers, where surgical excision is not always applicable, an alternate local treatment approach would be beneficial. This study aims to examine cutaneous pharmacokinetics and biodistribution of the PD-1 inhibitor nivolumab, locally delivered either by ablative fractional laser (AFL)-assisted passive diffusion or active intradermal injection, in vivo. MATERIALS AND METHODS: In vivo pig skin was either exposed to CO2 AFL (80 mJ/mb by two stacked pulses of 40 mJ/mb) at 5% or 15% density followed by topical application of nivolumab (1 mg/ml, 100 µl/10 × 10 mm) or intradermally injected with nivolumab (1 mg/ml, 100 µl). Cutaneous nivolumab delivery was evaluated at different timepoints (0, 1, 2, 4 hours and 2 days) at two tissue depths (100-800 and 900-1600 µm) by ELISA. Visualization of cutaneous biodistribution was shown in vertical tissue sections using HiLyte FluorTM 488 SE labeled nivolumab for fluorescence microscopy whereas nivolumab was DOTA-tagged with Dysprosium before the laser ablation-inductively coupled plasma-mass spectrometry analysis (LA-ICP-MS). RESULTS: Our in vivo study revealed different pharmacokinetic and biodistribution patterns for the AFL- and injection techniques. A superficial horizontal band-like uptake of nivolumab was provided with AFL-assisted passive diffusion whereas a deep focal deposition was seen with active intradermal injection, compared with controls showing remnant deposition on the skin surface. AFL-assisted nivolumab uptake in upper dermis peaked after 4 hours (p < 0.01). The cutaneous concentration of nivolumab achieved by intradermal injection was markedly higher than with AFL, the highest deposition with intradermal injection was detected at time 0 hours in both upper and deep dermis (p < 0.01) and decreased throughout the study period, although the concentration remained higher compared with saline control injections at all time points (0 hours -2 d) (p < 0.01). CONCLUSION: Local cutaneous delivery of nivolumab with either AFL or intradermal injection revealed two different pharmacokinetic and biodistribution patterns. Passive AFL-assisted diffusion of nivolumab resulted in enhanced uptake after 4 hours, while intradermal actively injected nivolumab showed immediate enhanced cutaneous deposition with retention up to 2 days after injection. The two local delivery techniques show potential for development of individualized treatment strategies depending on the clinical tumor appearance.


Assuntos
Inibidores de Checkpoint Imunológico , Lasers de Gás , Administração Cutânea , Animais , Sistemas de Liberação de Medicamentos , Injeções Intradérmicas , Pele/metabolismo , Absorção Cutânea , Suínos , Distribuição Tecidual
12.
Nat Methods ; 19(3): 311-315, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34824477

RESUMO

Highly multiplexed tissue imaging makes detailed molecular analysis of single cells possible in a preserved spatial context. However, reproducible analysis of large multichannel images poses a substantial computational challenge. Here, we describe a modular and open-source computational pipeline, MCMICRO, for performing the sequential steps needed to transform whole-slide images into single-cell data. We demonstrate the use of MCMICRO on tissue and tumor images acquired using multiple imaging platforms, thereby providing a solid foundation for the continued development of tissue imaging software.


Assuntos
Processamento de Imagem Assistida por Computador , Neoplasias , Diagnóstico por Imagem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Software
13.
J Synchrotron Radiat ; 28(Pt 5): 1296-1308, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34475279

RESUMO

X-rays are routinely used for structural studies through scattering, and femtosecond X-ray lasers can probe ultrafast dynamics. We aim to capture the femtosecond dynamics of liquid samples using simulations and deconstruct the interplay of ionization and atomic motion within the X-ray laser pulse. This deconstruction is resolution dependent, as ionization influences the low momentum transfers through changes in scattering form factors, while atomic motion has a greater effect at high momentum transfers through loss of coherence. Our methodology uses a combination of classical molecular dynamics and plasma simulation on a protic ionic liquid to quantify the contributions to the scattering signal and how these evolve with time during the X-ray laser pulse. Our method is relevant for studies of organic liquids, biomolecules in solution or any low-Z materials at liquid densities that quickly turn into a plasma while probed with X-rays.

14.
Plant J ; 108(3): 870-885, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34407245

RESUMO

At the morphological and anatomical levels, the ionome, or the elemental composition of an organism, is an understudied area of plant biology. In particular, the ionomic responses of plant-pathogen interactions are scarcely described, and there are no studies on immune reactions. In this study we explored two X-ray fluorescence (XRF)-based ionome visualisation methods (benchtop- and synchrotron-based micro-XRF [µXRF]), as well as the quantitative inductively coupled plasma optical emission spectroscopy (ICP-OES) method, to investigate the changes that occur in the ionome of compatible and incompatible plant-pathogen interactions. We utilised the agronomically important and comprehensively studied interaction between potato (Solanum tuberosum) and the late blight oomycete pathogen Phytophthora infestans as an example. We used one late blight-susceptible potato cultivar and two resistant transgenic plant lines (only differing from the susceptible cultivar in one or three resistance genes) both in control and P. infestans-inoculated conditions. In the lesions from the compatible interaction, we observed rearrangements of several elements, including a decrease of the mobile macronutrient potassium (K) and an increase in iron (Fe) and manganese (Mn), compared with the tissue outside the lesion. Interestingly, we observed distinctly different distribution patterns of accumulation at the site of inoculation in the resistant lines for calcium (Ca), magnesium (Mg), Mn and silicon (Si) compared to the susceptible cultivar. The results reveal different ionomes in diseased plants compared to resistant plants. Our results demonstrate a technical advance and pave the way for deeper studies of the plant-pathogen ionome in the future.


Assuntos
Interações Hospedeiro-Patógeno/fisiologia , Íons/análise , Phytophthora infestans/patogenicidade , Solanum tuberosum/microbiologia , Análise Espectral/métodos , Suscetibilidade a Doenças , Íons/metabolismo , Metais/metabolismo , Fósforo/metabolismo , Doenças das Plantas/microbiologia , Plantas Geneticamente Modificadas , Espectrometria por Raios X/instrumentação , Espectrometria por Raios X/métodos , Análise Espectral/instrumentação , Síncrotrons
15.
J Hazard Mater ; 417: 125955, 2021 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-33975168

RESUMO

Cadmium (Cd) is harmful to the environment and threatens human health. With the increasing use of cerium oxide nanoparticles (CeO2NPs) in extensive industries, investigating the combination of CeO2NPs and plants has attracted research interests for phytoremediation. Here, we explored the effects of CeO2NPs on Cd uptake, transport and the consequent Cd accumulation in Sedum alfredii. Exposure of 50 or 500 mg L-1 CeO2NPs alone had no apparent damaging effects on plant growth. However, upon Cd condition, the consistent CeO2NPs decreased Cd concentrations in the roots and shoots by up to 37%. Furthermore, the application of a metabolic inhibitor revealed that CeO2NPs mainly decreased the Cd uptake in roots by the apoplastic pathway. Simultaneously, CeO2NPs accelerated the development of Casparian strips (CSs) and suberin, which was further proven by the elevated expression levels of genes associated with their formation, SaCASP, SaGPAT5, SaKCS20 and SaCYP86A1. Compared to CeO2NPs added alone, the concurrent Cd decreased the Ce contents in the roots and altered its translocation from root to shoot. Taken together, both CeO2NPs and Cd influence the interactional uptake of both chemicals in roots of S. alfredii mainly via the apoplastic pathway which is primarily regulated by the development of CSs and suberin.


Assuntos
Nanopartículas , Sedum , Cádmio/toxicidade , Cério , Humanos , Raízes de Plantas
16.
Nat Plants ; 7(2): 137-143, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33594269

RESUMO

Zinc (Zn) is an essential micronutrient for plants and animals owing to its structural and catalytic roles in many proteins1. Zn deficiency affects around 2 billion people, mainly those who live on plant-based diets relying on crops from Zn-deficient soils2,3. Plants maintain adequate Zn levels through tightly regulated Zn homeostasis mechanisms involving Zn uptake, distribution and storage4, but evidence of how they sense Zn status is lacking. Here, we use in vitro and in planta approaches to show that the Arabidopsis thaliana F-group bZIP transcription factors bZIP19 and bZIP23, which are the central regulators of the Zn deficiency response, function as Zn sensors by binding Zn2+ ions to a Zn-sensor motif. Deletions or modifications of this Zn-sensor motif disrupt Zn binding, leading to a constitutive transcriptional Zn deficiency response, which causes a significant increase in plant and seed Zn accumulation. As the Zn-sensor motif is highly conserved in F-group bZIP proteins across land plants, the identification of this plant Zn sensor will promote new strategies to improve the Zn nutritional quality of plant-derived food and feed, and contribute to tackling the global Zn-deficiency health problem.


Assuntos
Arabidopsis/genética , Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Zinco/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
17.
Lasers Surg Med ; 53(1): 119-128, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32960987

RESUMO

BACKGROUND AND OBJECTIVES: Rising incidences of basal cell carcinoma (BCC) have increased the need for effective topical therapies. By enhancing cutaneous uptake of the chemotherapeutic agents, cisplatin and 5-fluorouracil (5-FU), laser-assisted delivery may provide a new combination treatment for BCC. Accordingly, this study aimed to evaluate tumor response, safety, and drug biodistribution in tumors and blood after topical laser-assisted 5-FU + CIS treatment in BCC patients. STUDY DESIGN/MATERIALS AND METHODS: This open-label, proof-of-concept trial investigated laser-assisted combination cisplatin + 5-FU treatment in 20 patients with histologically verified, low-risk superficial or nodular BCCs on the face (<20 mm) or trunk/extremities (<50 mm). After tumor demarcation guided by optical coherence tomography (OCT), BCCs were exposed to ablative fractional CO2 laser followed by 60 minutes topical cisplatin solution and 7-day exposure to 5% 5-FU cream under occlusion. After 30 days, treatment was repeated if any tumor residual was identified. Tumor response at day 30 and month 3 was assessed clinically as well as by OCT, reflectance confocal microscopy, and ultrasound, supplemented by histological verification at 3 months. Local skin reactions (LSRs) and side effects were evaluated on days 1, 3-5, 14, 30, and month 3. Drug detection in tumors and blood was performed in a subset of patients 1- and 24 hours after treatment. RESULTS: Nineteen patients completed the trial, with 32% (6/19) receiving a single treatment and 68% (13/19) treated twice. At 3 months, clinical clearance was seen in 18/19 patients with a corresponding 94% (17/18) achieving histological clearance. Baseline tumor thickness and subtype did not influence treatment number or clearance rate (P ≥ 0.61). LSRs were well-tolerated and consisted of erythema, edema, and erosion, followed by crusting by day 14. Erythema declined gradually by month 3, with 94% of patients and 79% of physicians rating cosmesis as "good" or "excellent." Scarring or hyperpigmentation was noted in 50% and 56%, respectively, while pain and infection were not observed during the follow-up period. Although chemotherapy uptake was visualized extending to deep skin layers, no systemic exposure to cisplatin or 5-FU was detected in patient blood. CONCLUSION: Laser-assisted cisplatin + 5-FU shows potential as an effective and tolerable treatment option for low-risk BCC, particularly in instances where self-application is not possible or where in-office, non-surgical therapy is preferred. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.


Assuntos
Carcinoma Basocelular , Lasers de Gás , Neoplasias Cutâneas , Carcinoma Basocelular/diagnóstico por imagem , Carcinoma Basocelular/tratamento farmacológico , Cisplatino , Fluoruracila , Humanos , Estudo de Prova de Conceito , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/tratamento farmacológico , Distribuição Tecidual
18.
Lasers Surg Med ; 53(1): 154-161, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32997833

RESUMO

BACKGROUND AND OBJECTIVES: PD-L1 is a tumor ligand that binds to the PD-1 receptor on immune cells, thereby inhibiting the antitumor immune response. The antibody nivolumab is a PD-1 inhibitor, Food and Drug Administration approved for systemic treatment of several aggressive cancer types. Topically applied nivolumab may hold potential as a future strategy to treat keratinocyte cancer, but its molecular properties preclude unassisted topical uptake. The aim of this study was to investigate uptake and biodistribution of topically delivered nivolumab, assisted by two physical enhancement techniques with different delivery kinetics; ablative fractional laser (AFL) and electronically controlled pneumatic injection (EPI). STUDY DESIGN/MATERIALS AND METHODS: In vitro porcine skin was exposed to CO2 AFL (20 mJ/mb, 5% density), followed by passive diffusion of nivolumab in a Franz cell (1 mg/ml, 18 hours, n = 6) or treated with EPI (4 bar) for immediate delivery of nivolumab (1 mg/ml, 10 minutes, n = 6). The resulting nivolumab skin concentrations were quantified by enzyme-linked immunosorbent assay (ELISA) at three skin depths (100, 500, and 1500 µm), comparing the uptake from assisted delivery with intact skin. Biodistribution of nivolumab in the skin for all interventions was visualized by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and fluorescence microscopy. RESULTS: Delivery of nivolumab by AFL-assisted passive diffusion and immediate EPI both resulted in significantly enhanced uptake of nivolumab in all skin depths compared with intact skin (P < 0.05). With AFL, nivolumab concentrations reached 86.3 µg/cm3 (100 µm), 105.8 µg/cm3 (500 µm), and 19.3 µg/cm3 (1500 µm), corresponding to 2-10% of the applied concentration, with the highest deposition in the mid dermis. Immediate EPI delivered 429.4 µg/cm3 (100 µm), 584.9 µg/cm3 (500 µm), and 295.9 µg/cm3 (1500 µm) into the skin, corresponding to 29-58% of the applied nivolumab concentration. From qualitative visualization of the biodistribution, it appeared that nivolumab distributed in a horizontal and continuous homogenous band in the upper and mid dermis through AFL-exposed skin, whereas EPI-delivery showed a deep focal deposition extending into the deep dermis. CONCLUSIONS: AFL-assisted passive diffusion and immediate EPI-assisted delivery show the potential to deliver therapeutic antibodies locally. Future in vivo and pharmacokinetic studies would reveal the full potential for topical antibody delivery by energy-based devices. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.


Assuntos
Lasers de Gás , Nivolumabe , Administração Cutânea , Animais , Sistemas de Liberação de Medicamentos , Nivolumabe/metabolismo , Pele/metabolismo , Suínos , Distribuição Tecidual
19.
New Phytol ; 229(5): 2446-2469, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33175410

RESUMO

The visual deficiency symptoms developing on plants constitute the ultimate manifestation of suboptimal nutrient supply. In classical plant nutrition, these symptoms have been extensively used as a tool to characterise the nutritional status of plants and to optimise fertilisation. Here we expand this concept by bridging the typical deficiency symptoms for each of the six essential macronutrients to their molecular and physiological functionalities in higher plants. We focus on the most recent insights obtained during the last decade, which now allow us to better understand the links between symptom and function for each element. A deep understanding of the mechanisms underlying the visual deficiency symptoms enables us to thoroughly understand how plants react to nutrient limitations and how these disturbances may affect the productivity and biodiversity of terrestrial ecosystems. A proper interpretation of visual deficiency symptoms will support the potential for sustainable crop intensification through the development of new technologies that facilitate automatised management practices based on imaging technologies, remote sensing and in-field sensors, thereby providing the basis for timely application of nutrients via smart and more efficient fertilisation.


Assuntos
Ecossistema , Plantas , Minerais , Nitrogênio , Nutrientes
20.
J Agric Food Chem ; 68(44): 12229-12240, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33070613

RESUMO

Breeding and engineering of biofortified crops will benefit from a better understanding of bottlenecks controlling micronutrient loading within the seeds. However, few studies have addressed the changes in micronutrient concentrations, localization, and speciation occurring over time. Therefore, we studied spatial patterns of zinc and iron accumulation during grain development in two barley lines with contrasting grain zinc concentrations. Microparticle-induced-X-ray emission and laser ablation-inductively coupled plasma mass spectrometry were used to determine tissue-specific accumulation of zinc, iron, phosphorus, and sulfur. Differences in zinc accumulation between the lines were most evident in the endosperm and aleurone. A gradual decrease in zinc concentrations from the aleurone to the underlying endosperm was observed, while iron and phosphorus concentrations decreased sharply. Iron co-localized with phosphorus in the aleurone, whereas zinc co-localized with sulfur in the sub-aleurone. We hypothesize that differences in grain zinc are largely explained by the endosperm storage capacity. Engineering attempts should be targeted accordingly.


Assuntos
Hordeum/metabolismo , Ferro/metabolismo , Sementes/química , Zinco/metabolismo , Grão Comestível/química , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Endosperma/química , Endosperma/metabolismo , Hordeum/química , Hordeum/crescimento & desenvolvimento , Ferro/análise , Micronutrientes/análise , Micronutrientes/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Zinco/análise
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