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1.
J Exp Bot ; 75(11): 3612-3623, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38511472

RESUMO

Desiccation tolerance evolved recurrently across diverse plant lineages to enable survival in water-limited conditions. Many resurrection plants are polyploid, and several groups have hypothesized that polyploidy contributed to the evolution of desiccation tolerance. However, due to the vast phylogenetic distance between resurrection plant lineages, the rarity of desiccation tolerance, and the prevalence of polyploidy in plants, this hypothesis has been difficult to test. Here, we surveyed natural variation in morphological, reproductive, and desiccation tolerance traits across several cytotypes of a single species to test for links between polyploidy and increased resilience. We sampled multiple natural populations of the resurrection grass Microchloa caffra across an environmental gradient ranging from mesic to xeric in South Africa. We describe two distinct ecotypes of M. caffra that occupy different extremes of the environmental gradient and exhibit consistent differences in ploidy, morphological, reproductive, and desiccation tolerance traits in both field and common growth conditions. Interestingly, plants with more polyploid genomes exhibited consistently higher recovery from desiccation, were less reproductive, and were larger than plants with smaller genomes and lower ploidy. These data indicate that selective pressures in increasingly xeric sites may play a role in maintaining and increasing desiccation tolerance and are mediated by changes in ploidy.


Assuntos
Poaceae , Poliploidia , Poaceae/genética , Poaceae/fisiologia , África do Sul , Dessecação , Adaptação Fisiológica/genética
2.
Magn Reson Med ; 87(4): 1952-1970, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34812528

RESUMO

PURPOSE: Low SNR in fluorine-19 (19 F) MRI benefits from cryogenically-cooled transceive surface RF probes (CRPs), but strong B1 inhomogeneities hinder quantification. Rapid acquisition with refocused echoes (RARE) is an SNR-efficient method for MRI of neuroinflammation with perfluorinated compounds but lacks an analytical signal intensity equation to retrospectively correct B1 inhomogeneity. Here, a workflow was proposed and validated to correct and quantify 19 F-MR signals from the inflamed mouse brain using a 19 F-CRP. METHODS: In vivo 19 F-MR images were acquired in a neuroinflammation mouse model with a quadrature 19 F-CRP using an imaging setup including 3D-printed components to acquire co-localized anatomical and 19 F images. Model-based corrections were validated on a uniform 19 F phantom and in the neuroinflammatory model. Corrected 19 F-MR images were benchmarked against reference images and overlaid on in vivo 1 H-MR images. Computed concentration uncertainty maps using Monte Carlo simulations served as a measure of performance of the B1 corrections. RESULTS: Our study reports on the first quantitative in vivo 19 F-MR images of an inflamed mouse brain using a 19 F-CRP, including in vivo T1 calculations for 19 F-nanoparticles during pathology and B1 corrections for 19 F-signal quantification. Model-based corrections markedly improved 19 F-signal quantification from errors > 50% to < 10% in a uniform phantom (p < 0.001). Concentration uncertainty maps ex vivo and in vivo yielded uncertainties that were generally < 25%. Monte Carlo simulations prescribed SNR ≥ 10.1 to reduce uncertainties < 10%, and SNR ≥ 4.25 to achieve uncertainties < 25%. CONCLUSION: Our model-based correction method facilitated 19 F signal quantification in the inflamed mouse brain when using the SNR-boosting 19 F-CRP technology, paving the way for future low-SNR 19 F-MRI applications in vivo.


Assuntos
Imageamento por Ressonância Magnética , Doenças Neuroinflamatórias , Animais , Imageamento por Ressonância Magnética/métodos , Camundongos , Imagens de Fantasmas , Ondas de Rádio , Estudos Retrospectivos
3.
Plant Cell Environ ; 45(9): 2607-2616, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35736139

RESUMO

Tracheid buckling may protect leaves in the dynamic environments of forest canopies, where rapid intensifications of evaporative demand, such as those brought on by changes in light availability, can result in sudden increases in transpiration rate. While treetop leaves function in reliably direct light, leaves below the upper crown must tolerate rapid, thermally driven increases in evaporative demand. Using synchrotron-based X-ray microtomography, we visualized impacts of experimentally induced water stress and subsequent fogging on living cells in redwood leaves, adding ecological and functional context through crown-wide explorations of variation in leaf physiology and microclimate. Under drought, leaf transfusion tracheids buckle, releasing water that supplies sufficient temporal reserves for leaves to reduce stomatal conductance safely while stopping the further rise of tension. Tracheid buckling fraction decreases with height and is closely coordinated with transfusion tissue capacity and stomatal conductance to provide temporal reserves optimized for local variation in microclimate. Foliar water uptake fully restores collapsed and air-filled transfusion tracheids in leaves on excised shoots, suggesting that trees may use aerial water sources for recovery. In the intensely variable deep-crown environment, foliar water uptake can allow for repetitive cycles of tracheid buckling and unbuckling, protecting the tree from damaging levels of hydraulic tension and supporting leaf survival.


Assuntos
Sequoia , Árvores , Secas , Folhas de Planta/fisiologia , Transpiração Vegetal , Sequoia/fisiologia , Árvores/fisiologia , Tempo (Meteorologia)
4.
Am J Bot ; 109(4): 564-579, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35274309

RESUMO

PREMISE: Trees in wet forests often have features that prevent water films from covering stomata and inhibiting gas exchange, while many trees in drier environments use foliar water uptake to reduce water stress. In forests with both wet and dry seasons, evergreen trees would benefit from producing leaves capable of balancing rainy-season photosynthesis with summertime water absorption. METHODS: Using samples collected from across the vertical gradient in tall redwood (Sequoia sempervirens) crowns, we estimated tree-level foliar water uptake and employed physics-based causative modeling to identify key functional traits that determine uptake potential by setting hydraulic resistance. RESULTS: We showed that Sequoia has two functionally distinct shoot morphotypes. While most shoots specialize in photosynthesis, the axial shoot type is capable of much greater foliar water uptake, and its within-crown distribution varies with latitude. A suite of leaf surface traits cause hydraulic resistance, leading to variation in uptake capacity among samples. CONCLUSIONS: Shoot dimorphism gives tall Sequoia trees the capacity to absorb up to 48 kg H2 O h-1 during the first hour of leaf wetting, ameliorating water stress while presumably maintaining high photosynthetic capacity year round. Geographic variation in shoot dimorphism suggests that plasticity in shoot-type distribution and leaf surface traits helps Sequoia maintain a dominate presence in both wet and dry forests.


Assuntos
Sequoia , Desidratação , Fotossíntese , Folhas de Planta , Caracteres Sexuais , Árvores
5.
Plant Cell Environ ; 44(6): 1728-1740, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33665817

RESUMO

Plants can absorb water through their leaf surfaces, a phenomenon commonly referred to as foliar water uptake (FWU). Despite the physiological importance of FWU, the pathways and mechanisms underlying the process are not well known. Using a novel experimental approach, we parsed out the contribution of the stomata and the cuticle to FWU in two species with Mediterranean (Prunus dulcis) and temperate (Pyrus communis) origin. The hydraulic parameters of FWU were derived by analysing mass and water potential changes of leaves placed in a fog chamber. Leaves were previously treated with abscisic acid to force stomata to remain closed, with fusicoccin to remain open, and with water (control). Leaves with open stomata rehydrated two times faster than leaves with closed stomata and attained approximately three times higher maximum fluxes and hydraulic conductance. Based on FWU rates, we propose that rehydration through stomata occurs primarily via diffusion of water vapour rather than in liquid form even when leaf surfaces are covered with a water film. We discuss the potential mechanisms of FWU and the significance of both stomatal and cuticular pathways for plant productivity and survival.


Assuntos
Folhas de Planta/metabolismo , Estômatos de Plantas/fisiologia , Prunus dulcis/metabolismo , Pyrus/metabolismo , Água/metabolismo , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Glicosídeos/farmacologia , Cinética , Microscopia Eletrônica de Varredura , Folhas de Planta/ultraestrutura , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/ultraestrutura
6.
Oncologist ; 25(10): e1562-e1573, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32888360

RESUMO

BACKGROUND: The COVID-19 outbreak has resulted in collision between patients infected with SARS-CoV-2 and those with cancer on different fronts. Patients with cancer have been impacted by deferral, modification, and even cessation of therapy. Adaptive measures to minimize hospital exposure, following the precautionary principle, have been proposed for cancer care during COVID-19 era. We present here a consensus on prioritizing recommendations across the continuum of sarcoma patient care. MATERIAL AND METHODS: A total of 125 recommendations were proposed in soft-tissue, bone, and visceral sarcoma care. Recommendations were assigned as higher or lower priority if they cannot or can be postponed at least 2-3 months, respectively. The consensus level for each recommendation was classified as "strongly recommended" (SR) if more than 90% of experts agreed, "recommended" (R) if 75%-90% of experts agreed and "no consensus" (NC) if fewer than 75% agreed. Sarcoma experts from 11 countries within the Sarcoma European-Latin American Network (SELNET) consortium participated, including countries in the Americas and Europe. The European Society for Medical Oncology-Magnitude of clinical benefit scale was applied to systemic-treatment recommendations to support prioritization. RESULTS: There were 80 SRs, 35 Rs, and 10 NCs among the 125 recommendations issued and completed by 31 multidisciplinary sarcoma experts. The consensus was higher among the 75 higher-priority recommendations (85%, 12%, and 3% for SR, R, and NC, respectively) than in the 50 lower-priority recommendations (32%, 52%, and 16% for SR, R, and NC, respectively). CONCLUSION: The consensus on 115 of 125 recommendations indicates a high-level of convergence among experts. The SELNET consensus provides a tool for sarcoma multidisciplinary treatment committees during the COVID-19 outbreak. IMPLICATIONS FOR PRACTICE: The Sarcoma European-Latin American Network (SELNET) consensus on sarcoma prioritization care during the COVID-19 era issued 125 pragmatical recommendations distributed as higher or lower priority to protect critical decisions on sarcoma care during the COVID-19 pandemic. A multidisciplinary team from 11 countries reached consensus on 115 recommendations. The consensus was lower among lower-priority recommendations, which shows reticence to postpone actions even in indolent tumors. The European Society for Medical Oncology-Magnitude of Clinical Benefit scale was applied as support for prioritizing systemic treatment. Consensus on 115 of 125 recommendations indicates a high level of convergence among experts. The SELNET consensus provides a practice tool for guidance in the decisions of sarcoma multidisciplinary treatment committees during the COVID-19 outbreak.


Assuntos
COVID-19/epidemiologia , Oncologia/organização & administração , Oncologia/normas , Sarcoma/terapia , COVID-19/prevenção & controle , Consenso , Europa (Continente)/epidemiologia , Humanos , América Latina/epidemiologia , Assistência ao Paciente/normas , Guias de Prática Clínica como Assunto , SARS-CoV-2 , Sarcoma/diagnóstico
7.
Magn Reson Med ; 84(5): 2684-2701, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32447779

RESUMO

PURPOSE: The use of surface radiofrequency (RF) coils is common practice to boost sensitivity in (pre)clinical MRI. The number of transceive surface RF coils is rapidly growing due to the surge in cryogenically cooled RF technology and ultrahigh-field MRI. Consequently, there is an increasing need for effective correction of the excitation field ( B1+ ) inhomogeneity inherent in these coils. Retrospective B1 correction permits quantitative MRI, but this usually requires a pulse sequence-specific analytical signal intensity (SI) equation. Such an equation is not available for fast spin-echo (Rapid Acquisition with Relaxation Enhancement, RARE) MRI. Here we present, test, and validate retrospective B1 correction methods for RARE. METHODS: We implemented the commonly used sensitivity correction and developed an empirical model-based method and a hybrid combination of both. Tests and validations were performed with a cryogenically cooled RF probe and a single-loop RF coil. Accuracy of SI quantification and T1 contrast were evaluated after correction. RESULTS: The three described correction methods achieved dramatic improvements in B1 homogeneity and significantly improved SI quantification and T1 contrast, with mean SI errors reduced from >40% to >10% following correction in all cases. Upon correction, images of phantoms and mouse heads demonstrated homogeneity comparable to that of images acquired with a volume resonator. This was quantified by SI profile, SI ratio (error < 10%), and percentage of integral uniformity (PIU > 80% in vivo and ex vivo compared to PIU > 87% with the reference RF coil). CONCLUSION: This work demonstrates the efficacy of three B1 correction methods tailored for transceive surface RF probes and RARE MRI. The corrected images are suitable for quantification and show comparable results between the three methods, opening the way for T1 measurements and X-nuclei quantification using surface transceiver RF coils. This approach is applicable to other MR techniques for which no analytical SI exists.


Assuntos
Imageamento por Ressonância Magnética , Ondas de Rádio , Animais , Camundongos , Imagens de Fantasmas , Estudos Retrospectivos
8.
New Phytol ; 225(6): 2314-2330, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31808954

RESUMO

Parenchyma cells in the xylem store nonstructural carbohydrates (NSC), providing reserves of energy that fuel woody perennials through periods of stress and/or limitations to photosynthesis. If the capacity for storage is subject to selection, then the fraction of wood occupied by living parenchyma should increase towards stressful environments. Ray parenchyma fraction (RPF) and seasonal NSC dynamics were quantified for 12 conifers and three oaks along a transect spanning warm dry foothills (500 m above sea level) to cold wet treeline (3250 m asl) in California's central Sierra Nevada. Mean RPF was lower for both conifer and oak species with warmer dryer ranges. RPF variability increased with elevation or in relation to associated climatic variables in conifers - treeline-dominant Pinus albicaulis had the lowest mean RPF measured (c. 3.7%), but the highest environmentally standardized variability index. Conifer RPF variability was explained by environment, increasing predominantly towards cooler wetter range edges. In oaks, NSC was explained by environment - values increasing for evergreen and decreasing for deciduous oaks with elevation. Lastly, all species surveyed appear to prioritize filling available RPF with sugar to achieve molarities that balance reasonable tensions over starch to maximize stored carbon. RPF responds to environment but is unlikely to spatially constrain NSC storage.


Assuntos
Pinus , Árvores , Metabolismo dos Carboidratos , Carboidratos , Xilema
9.
Anal Bioanal Chem ; 412(24): 6391-6405, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32285184

RESUMO

Despite the recent advances in the standardization of untargeted metabolomics workflows, there is still a lack of attention to specific data treatment strategies that require deep knowledge of the biological problem and need to be applied after a well-thought out process to understand the effect of the practice. One of those strategies is data normalization. Data-driven assumptions are critical especially addressing unwanted variation present in the biological model as it can be the case in heterogeneous tissues, cells with different sizes or biofluids with different concentrations. Chronic kidney disease (CKD) is a widespread disorder affecting kidney structure and function. Animal models are being developed to be able to get valuable insights into the etiopathogenesis of the condition and effect of the treatments. Moreover, diagnosis and disease staging still require defining appropriate biomarkers. Untargeted metabolomics has the potential to deal with those challenges. Renal fibrosis is one of the consequences of kidney injury which greatly affects the concentration of metabolites in the same quantity of sample. To overcome this challenge, several data normalization strategies have been applied, following a multilevel normalization method with the overall aim of focussing on the relevant biological information and reducing the influence of disturbing factors. A comprehensive evaluation of the performance of the normalization strategies, both on methods assessing the intragroup variation and on the impact on differential analysis, is provided. Finally, we present evidence of the importance of biological-model-driven guided normalization methods and discuss multiple criteria that need to be taken into consideration to obtain robust and reliable data. Special concern is transmitted on the misleading conclusions that might be the consequence of inappropriate data pre-treatment solutions applied for untargeted methods. Graphical abstract.


Assuntos
Rim/metabolismo , Metabolômica/métodos , Insuficiência Renal Crônica/metabolismo , Animais , Análise Discriminante , Modelos Animais de Doenças , Humanos , Análise dos Mínimos Quadrados , Masculino , Metaboloma , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
10.
MAGMA ; 32(1): 51-61, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30515642

RESUMO

OBJECTIVE: This study examines the influence of the environmental factor temperature on the 19F NMR characteristics of fluorinated compounds in phantom studies and in tissue. MATERIALS AND METHODS: 19F MR mapping and MR spectroscopy techniques were used to characterize the 19F NMR characteristics of perfluoro-crown ether (PFCE), isoflurane, teriflunomide, and flupentixol. T1 and T2 mapping were performed, while temperature in the samples was changed (T = 20-60 °C) and monitored using fiber optic measurements. In tissue, T1 of PFCE nanoparticles was determined at physiological temperatures and compared with the T1-measured at room temperature. RESULTS: Studies on PFCE, isoflurane, teriflunomide, and flupentixol showed a relationship between temperature and their physicochemical characteristics, namely, chemical shift, T1 and T2. T1 of PFCE nanoparticles was higher at physiological body temperatures compared to room temperature. DISCUSSION: The impact of temperature on the 19F NMR parameters of fluorinated compounds demonstrated in this study not only opens a trajectory toward 19F MR-based thermometry, but also indicates the need for adapting MR sequence parameters according to environmental changes such as temperature. This will be an absolute requirement for detecting fluorinated compounds by 19F MR techniques in vivo.


Assuntos
Imagem por Ressonância Magnética de Flúor-19/instrumentação , Flúor/química , Termometria/instrumentação , Animais , Crotonatos/química , Éteres de Coroa/química , Feminino , Tecnologia de Fibra Óptica , Imagem por Ressonância Magnética de Flúor-19/métodos , Flupentixol/química , Hidroxibutiratos , Hipertermia Induzida , Processamento de Imagem Assistida por Computador , Isoflurano , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas , Nitrilas , Imagens de Fantasmas , Preparações Farmacêuticas/química , Marcadores de Spin , Temperatura , Termometria/métodos , Toluidinas/química
11.
MAGMA ; 32(1): 37-49, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30421250

RESUMO

OBJECTIVE: Fluorine MR would benefit greatly from enhancements in signal-to-noise ratio (SNR). This study examines the sensitivity gain of 19F MR that can be practically achieved when moving from 9.4 to 21.1 T. MATERIALS AND METHODS: We studied perfluoro-15-crown-5-ether (PFCE) at both field strengths (B0), as a pure compound, in the form of nanoparticles (NP) as employed to study inflammation in vivo, as well as in inflamed tissue. Brains, lymph nodes (LNs) and spleens were obtained from mice with experimental autoimmune encephalomyelitis (EAE) that had been administered PFCE NPs. All samples were measured at both B0 with 2D-RARE and 2D-FLASH using 19F volume radiofrequency resonators together. T1 and T2 of PFCE were measured at both B0 strengths. RESULTS: Compared to 9.4 T, an SNR gain of > 3 was observed for pure PFCE and > 2 for PFCE NPs at 21.1 T using 2D-FLASH. A dependency of 19F T1 and T2 relaxation on B0 was demonstrated. High spatially resolved 19F MRI of EAE brains and LNs at 21.1 T revealed signals not seen at 9.4 T. DISCUSSION: Enhanced SNR and T1 shortening indicate the potential benefit of in vivo 19F MR at higher B0 to study inflammatory processes with greater detail.


Assuntos
Éteres de Coroa/química , Imagem por Ressonância Magnética de Flúor-19 , Flúor/química , Inflamação/tratamento farmacológico , Animais , Encéfalo/diagnóstico por imagem , Calibragem , Meios de Contraste/química , Encefalomielite Autoimune Experimental/diagnóstico por imagem , Feminino , Linfonodos/diagnóstico por imagem , Camundongos , Nanopartículas , Ondas de Rádio , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Razão Sinal-Ruído , Marcadores de Spin , Baço/diagnóstico por imagem
12.
Plant Cell Environ ; 41(8): 1886-1894, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29740843

RESUMO

Soil water transported via the petiole is a primary rehydration pathway for leaves of water-stressed plants. Leaves may also rehydrate by absorbing water via their epidermal surfaces. The mechanisms and physiological relevance of this water pathway, however, remain unclear, as the associated hydraulic properties are unknown. To gain insight into the foliar water absorption process, we compared rehydration kinetics via the petiole and surface of Prunus dulcis and Quercus lobata leaves. Petiole rehydration could be described by a double exponential function suggesting that 2 partly isolated water pools exist in leaves of both species. Surface rehydration could be described by a logistic function, suggesting that leaves behave as a single water pool. Whereas full leaf rehydration via the petiole required approximately 20 min, it took over 150 and 300 min via the surface of P. dulcis and Q. lobata, respectively. Such differences were attributed to the high resistance imposed by the leaf surface and especially the cuticle. The minimum resistance to surface rehydration was estimated to be 6.6 × 102 (P. dulcis) and 2.6 × 103  MPa·m2 ·s·g-1 (Q. lobata), which is remarkably higher than estimated for petiole rehydration. These results are discussed in a physiological context.


Assuntos
Folhas de Planta/metabolismo , Água/metabolismo , Desidratação , Cinética , Epiderme Vegetal/metabolismo , Epiderme Vegetal/fisiologia , Folhas de Planta/fisiologia , Prunus dulcis/metabolismo , Prunus dulcis/fisiologia , Quercus/metabolismo , Quercus/fisiologia , Água/fisiologia
13.
Physiol Plant ; 157(2): 205-20, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26756450

RESUMO

Plant cuticles have been traditionally classified on the basis of their ultrastructure, with certain chemical composition assumptions. However, the nature of the plant cuticle may be misinterpreted in the prevailing model, which was established more than 150 years ago. Using the adaxial leaf cuticle of Ficus elastica, a study was conducted with the aim of analyzing cuticular ultrastructure, chemical composition and the potential relationship between structure and chemistry. Gradual chemical extractions and diverse analytical and microscopic techniques were performed on isolated leaf cuticles of two different stages of development (i.e. young and mature leaves). Evidence for the presence of cutan in F. elastica leaf cuticles has been gained after chemical treatments and tissue analysis by infrared spectroscopy and electron microscopy. Significant calcium, boron and silicon concentrations were also measured in the cuticle of this species. Such mineral elements which are often found in plant cell walls may play a structural role and their presence in isolated cuticles further supports the interpretation of the cuticle as the most external region of the epidermal cell wall. The complex and heterogeneous nature of the cuticle, and constraints associated with current analytical procedures may limit the chance for establishing a relationship between cuticle chemical composition and structure also in relation to organ ontogeny.


Assuntos
Parede Celular , Ficus , Epiderme Vegetal , Parede Celular/química , Parede Celular/ultraestrutura , Ficus/química , Ficus/ultraestrutura , Lipídeos/análise , Microscopia Eletrônica , Minerais/análise , Epiderme Vegetal/química , Epiderme Vegetal/ultraestrutura , Folhas de Planta/química , Folhas de Planta/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Ceras/química
14.
Microsurgery ; 36(6): 501-6, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26456638

RESUMO

Fractures of the calcaneus are associated with secondary osteoarthritis of the subtalar joint. In a persistent nonunion, vascularized bone flaps offer superior biologic and mechanical properties as well as accelerates joint fusion and decreases morbidity. In this report, we present results of the use of vascularized iliac bone free flap for treating subtalar failed fusions in two patients. Two patients sustained calcaneal fractures due to foot trauma, which were initially or subsequently treated with subtalar arthrodesis. Case one developed septic subtalar nonunion during treatment and case two failed three attempts at subtalar arthrodeses. The iliac crest bone flap harvested measured 4 × 4 cm (case one) and 3 × 3 cm (case two). The flap was pedicled by the deep circumflex iliac artery, which was anastomosed to the anterior tibial artery at the recipient site. No flap donor or recipient site complications occurred. Fusion was confirmed on CT scan and weight bearing was initiated at 5-6 months. At latest follow up (1-2 years), no complications occurred. Our results show that subtalar nonunion treatment with a vascularized iliac bone flap may be feasible and such a reconstruction could be clinically successful. © 2015 Wiley Periodicals, Inc. Microsurgery 36:501-506, 2016.


Assuntos
Artrodese/métodos , Transplante Ósseo/métodos , Calcâneo/lesões , Fraturas não Consolidadas/cirurgia , Retalhos de Tecido Biológico/transplante , Ílio/transplante , Articulação Talocalcânea/cirurgia , Adulto , Calcâneo/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade
15.
bioRxiv ; 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39005423

RESUMO

While the triggers for the metastatic transformation of breast cancer (BC) cells remain unknown, recent evidence suggests that intrinsic cellular metabolism could be a crucial driver of migratory disposition and chemoresistance. Aiming to decode the molecular mechanisms involved in BC cell metabolic maneuvering, we study how a ketomimetic (ketone body rich, low glucose) medium affects Doxorubicin (DOX) susceptibility and invasive disposition of BC cells. We quantified glycocalyx sialylation and found an inverse correlation with DOX-induced cytotoxicity and DOX internalization. These measurements were coupled with single-cell metabolic imaging, bulk migration studies, along with transcriptomic and metabolomic analyses. Our findings revealed that a ketomimetic medium enhances chemoresistance and invasive disposition of BC cells via two main oncogenic pathways: hypersialylation and lipid synthesis. We propose that the crosstalk between these pathways, juxtaposed at the synthesis of the glycan precursor UDP-GlcNAc, furthers advancement of a metastatic phenotype in BC cells under ketomimetic conditions.

16.
bioRxiv ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-38903080

RESUMO

The blood-brain barrier (BBB), formed by specialized brain microvascular endothelial cells (BMECs), regulates brain function in health and disease. In vitro modeling of the human BBB is limited by the lack of robust hiPSC protocols to generate BMECs. Here, we report generation, transcriptomic and functional characterization of reprogrammed BMECs (rBMECs) by combining hiPSC differentiation into BBB-primed endothelial cells and reprogramming with two BBB transcription factors FOXF2 and ZIC3. rBMECs express a subset of the BBB gene repertoire including tight junctions and transporters, exhibit stronger paracellular barrier properties, lower caveolar-mediated transcytosis, and similar p-Glycoprotein activity compared to primary HBMECs. They can acquire an inflammatory phenotype when treated with oligomeric Aß42. rBMECs integrate with hiPSC-derived pericytes and astrocytes to form a 3D neurovascular system using the MIMETAS microfluidics platform. This novel 3D system resembles the in vivo BBB at structural and functional levels to enable investigation of pathogenic mechanisms of neurological diseases.

17.
Anal Chim Acta ; 1312: 342758, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38834268

RESUMO

BACKGROUND: The selection of the sample treatment strategy is a crucial step in the metabolomics workflow. Solid phase microextraction (SPME) is a sample processing methodology with great potential for use in untargeted metabolomics of tissue samples. However, its utilization is not as widespread as other standard protocols involving steps of tissue collection, metabolism quenching, homogenization, and extraction of metabolites by solvents. Since SPME allows us to perform all these steps in one action in tissue samples, in addition to other advantages, it is necessary to know whether this methodology produces similar or comparable metabolome and lipidome coverage and performance to classical methods. RESULTS: SPME and homogenization with solid-liquid extraction (Homo-SLE) sample treatment methods were applied to healthy murine kidney tissue, followed by comprehensive metabolomics and lipidomics analyses. In addition, it has been tested whether freezing and storage of the tissue causes alterations in the renal metabolome and lipidome, so the analyses were performed on fresh and frozen tissue samples Lipidomics analysis revealed the exclusive presence of different structural membrane and intracellular lipids in the Homo-SLE group. Conversely, all annotated metabolites were detected in both groups. Notably, the freezing of the sample mainly causes a decrease in the levels of most lipid species and an increase in metabolites such as amino acids, purines, and pyrimidines. These alterations are principally detected in a statistically significant way by SPME methodology. Finally, the samples of both methodologies show a positive correlation in all the analyses. SIGNIFICANCE: These results demonstrate that in SPME processing, as long as the fundamentals of non-exhaustive extraction in a pre-equilibrium kinetic regime, extraction in a tissue localized area, the chemistry of the fiber coating and non-homogenization of the tissue are taken into account, is an excellent method to use in kidney tissue metabolomics; since this methodology presents an easy-to-use, efficient, and less invasive approach that simplifies the different sample processing steps.


Assuntos
Rim , Metabolômica , Microextração em Fase Sólida , Microextração em Fase Sólida/métodos , Animais , Metabolômica/métodos , Rim/metabolismo , Rim/química , Camundongos , Extração Líquido-Líquido/métodos , Metaboloma , Masculino , Camundongos Endogâmicos C57BL
18.
J Hum Lact ; 39(4): 679-687, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37571838

RESUMO

BACKGROUND: Breastfeeding confers significant maternal and infant benefits; however, breastfeeding rates remain suboptimal in the United States. A parent's decision to breastfeed is influenced by non-modifiable and modifiable factors, including breastfeeding knowledge and self-efficacy. There is a positive correlation between high maternal self-efficacy and breastfeeding duration. Parents increasingly rely on technology for health information. RESEARCH AIM: To determine if a smartphone application affected maternal self-efficacy and breastfeeding exclusivity rates. METHOD: This study was a randomized, controlled pilot study examining the effect of an educational program, included in a smartphone application, on breastfeeding self-efficacy (assessed in postpartum Week 1 and Weeks 4-6) and breastfeeding rates (assessed in postpartum Weeks 4-6). Forty participants were recruited using block randomization to intervention (17 of 20 completed the study) and usual care (19 of 20 completed the study) groups. To examine the pre-test/post-test difference in the Breastfeeding Self-Efficacy Scale - Short Form total scores, a change in score (post-intervention minus pre-intervention) was calculated for each parent. RESULT: The intervention group (phone application and usual care) showed greater change in self-efficacy scores (M = 7.6, SD = 7.8) compared to the control group (usual care; M = 1.2, SD = 3.7, p = .001). The rate of exclusive breastfeeding was nearly twice as high in the intervention group as in the control group, but did not reach statistical significance (p = .093). CONCLUSION: The investigators found enhanced breastfeeding self-efficacy and breastfeeding rates among postpartum women receiving a smartphone educational program in the first 6 weeks postpartum. Further studies on smartphone interventions will develop our understanding of this technology in improving breastfeeding rates.


Assuntos
Aleitamento Materno , Período Pós-Parto , Lactente , Feminino , Humanos , Projetos Piloto , Pais , Autoeficácia
19.
Ecology ; 104(8): e4112, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37252804

RESUMO

Analysis of functional traits is a cornerstone of ecology, yet individual traits seldom explain useful amounts of variation in species distribution or climatic tolerance, and their functional significance is rarely validated experimentally. Multivariate suites of interacting traits could build an understanding of ecological processes and improve our ability to make sound predictions of species success in our rapidly changing world. We use foliar water uptake capacity as a case study because it is increasingly considered to be a key functional trait in plant ecology due to its importance for stress-tolerance physiology. However, the traits behind the trait, that is, the features of leaves that determine variation in foliar water uptake rates, have not been assembled into a widely applicable framework for uptake prediction. Focusing on trees, we investigated relationships among 25 structural traits, leaf osmotic potential (a source of free energy to draw water into leaves), and foliar water uptake in 10 diverse angiosperm and conifer species. We identified consistent, multitrait "uptake syndromes" for both angiosperm and conifer trees, with differences in key traits revealing suspected differences in the water entry route between these two clades and an evolutionarily significant divergence in the function of homologous structures. A literature review of uptake-associated functional traits, which largely documents similar univariate relationships, provides additional support for our proposed "uptake syndrome." Importantly, more than half of shared traits had opposite-direction influences on the capacity of leaves to absorb water in angiosperms and conifers. Taxonomically targeted multivariate trait syndromes provide a useful tool for trait selection in ecological research, while highlighting the importance of micro-traits and the physiological verification of their function for advancing trait-based ecology.


Assuntos
Magnoliopsida , Traqueófitas , Árvores/fisiologia , Água/análise , Ecologia , Traqueófitas/fisiologia , Folhas de Planta/química
20.
Front Mol Biosci ; 10: 1161036, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37377862

RESUMO

Background: Chronic kidney disease (CKD) is characterized by the progressive and irreversible deterioration of kidney function and structure with the appearance of renal fibrosis. A significant decrease in mitochondrial metabolism, specifically a reduction in fatty acid oxidation (FAO) in tubular cells, is observed in tubulointerstitial fibrosis, whereas FAO enhancement provides protection. Untargeted metabolomics offers the potential to provide a comprehensive analysis of the renal metabolome in the context of kidney injury. Methodology: Renal tissue from a carnitine palmitoyl transferase 1a (Cpt1a) overexpressing mouse model, which displays enhanced FAO in the renal tubule, subjected to folic acid nephropathy (FAN) was studied through a multiplatform untargeted metabolomics approach based on LC-MS, CE-MS and GC-MS analysis to achieve the highest coverage of the metabolome and lipidome affected by fibrosis. The expression of genes related to the biochemical routes showing significant changes was also evaluated. Results: By combining different tools for signal processing, statistical analysis and feature annotation, we were able to identify variations in 194 metabolites and lipids involved in many metabolic routes: TCA cycle, polyamines, one-carbon metabolism, amino acid metabolism, purine metabolism, FAO, glycerolipids and glycerophospholipids synthesis and degradation, glycosphingolipids interconversion, and sterol metabolism. We found several metabolites strongly altered by FAN, with no reversion induced by Cpt1a overexpression (v.g. citric acid), whereas other metabolites were influenced by CPT1A-induced FAO (v.g. glycine-betaine). Conclusion: It was implemented a successful multiplatform metabolomics approach for renal tissue analysis. Profound metabolic changes accompany CKD-associated fibrosis, some associated with tubular FAO failure. These results highlight the importance of addressing the crosstalk between metabolism and fibrosis when undertaking studies attempting to elucidate the mechanism of CKD progression.

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