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1.
Palliat Med ; : 2692163231219682, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38226491

RESUMO

BACKGROUND: Evidence suggests that involving General Practitioners in the care of patients with palliative care needs may improve patient outcomes. AIM: To evaluate whether a two-tiered intervention involving training in palliative care and a new consultation model in primary care for patients with palliative care needs is feasible and could reduce patients' symptom burden. DESIGN: Before-after study including an internal pilot. SETTING/PARTICIPANTS: Nine general practitioners working in a health region in Portugal and 53 patients with palliative care needs from their patient lists were recruited. General Practitioners received training in palliative care and used a new primary palliative care consultation model, with medical consultations every 3 weeks for 12 weeks. The primary outcome was physical symptom burden, self-reported using the Integrated Palliative care Outcome Scale (IPOS) patient version (min.0-max.1000). Secondary outcomes included emotional symptoms (min.0-max.400) and communication/practical issues (min.0-max.300). RESULTS: Of the 35/53 patients completed the 12-week intervention (mean age 72.53 years, SD = 13.45; 54.7% female). All had advanced disease: one third had cancer (n = 13), one third had congestive heart failure (n = 12); others had chronic kidney disease and chronic obstructive pulmonary disease. After the 12 weeks of intervention, there was a reduction in physical symptom burden [mean difference from baseline of 71.42 (95%CI 37.01-105.85) with a medium-large effect size (0.71], and in emotional symptom burden [mean difference 42.86 (95%CI 16.14-69.58), with a medium effect size (0.55)]. No difference was found for communication/practical issues. CONCLUSIONS: Our intervention can be effective in reducing patients' physical and emotional symptoms. TRIAL REGISTRATION: ClinicalTrials.gov ID - NCT05244590. Registration: 14th February 2022.

2.
Biology (Basel) ; 12(4)2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-37106708

RESUMO

Along with population growth, global climate change represents a critical threat to agricultural production, compromising the goal of achieving food and nutrition security for all. It is urgent to create sustainable and resilient agri-food systems capable of feeding the world without debilitating the planet. The Food and Agriculture Organization of the United Nations (FAO) refers to pulses as a superfood, as one of the most nutritious crops with high health benefits. Considered to be low-cost, many can be produced in arid lands and have an extended shelf-life. Their cultivation helps reduce greenhouse gases and increases carbon sequestration, also improving soil fertility. Cowpea, Vigna unguiculata (L.) Walp. is particularly drought tolerant, with a wide diversity of landraces adapted to different environments. Considering the importance of knowing and valuing the genetic variability of this species in Portugal, this study assessed the impact of drought on four landraces of cowpea (L1 to L4) from different regions of the country and a national commercial variety (CV) as a reference. The development and evaluation of morphological characteristics were monitored in response to terminal drought (imposed during the reproductive phase), and its effects were evaluated on the yield and quality of the produced grain, namely the weight of 100 grains, color, protein content, and soluble sugars. Under drought conditions, the landraces L1 and L2 showed early maturation as a strategy to avoid water deficit. Morphological alteration of the aerial part of the plants was evident in all genotypes, with a rapid reduction in the number of leaves and a reduction in the number of flowers and pods by between 44 and 72%. The parameters of grain quality, the weight of 100 grains, color, protein, and soluble sugars did not vary significantly, except for sugars of the raffinose family that is associated with the adaptive mechanisms of plants to drought. The performance and maintenance of the evaluated characteristics reflect the adaptation acquired in the past by exposure to the Mediterranean climate, highlighting the potential agronomic and genetic value, still little exploited, that could contribute to production stability, preserved nutritional value, and food safety under water stress.

3.
Plants (Basel) ; 12(4)2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36840194

RESUMO

Cowpea (Vigna unguiculata (L.) Walp.) is currently a legume crop of minor importance in Europe but a highly relevant staple crop in Africa and the second most cultivated legume in Mozambique. In Portugal and Mozambique, cowpea's phenotypic and genetic variation has been maintained locally by farmers in some areas. We used the molecular markers SSR, SilicoDArT and SNP to analyze the genetic diversity and population structure of 97 cowpea accessions, mainly from Portugal (Southern Europe) and Mozambique (Southern Africa). As far as we know, this is the first time that the genetic variation and the relationship between cowpea landraces collected in Portugal with those originated in Mozambique is reported. Despite the shared historical past, the Portuguese landraces did not share a common genetic background with those from Mozambique, and two different gene pools were revealed. Knowledge of the genetic structure of cowpea landraces offers an opportunity for individual selection within landraces adapted to particular eco-physiological conditions and suggests the existence of a valuable gene pool for exploitation in future Portugal-PALOP (Portuguese-speaking African countries) cowpea breeding programs.

4.
Plants (Basel) ; 11(5)2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35270063

RESUMO

Cowpea (Vigna unguiculata) is a robust legume; nevertheless, yield is always affected by drought, especially when it occurs during reproductive growth and seed filling. Considered a key crop in the effort to attain food security, and a suitable crop for a scenario of climate change, modern disregard for cowpea landraces is particularly detrimental as it causes genetic variability loss, compromising breeding efforts. To contribute to the evaluation of the cowpea germplasm, four Portuguese landraces (L1, L2, L3, L4) were compared with a commercial variety (CV) to evaluate their physiological responses to terminal drought and their inter-variation on productivity, under semi-controlled conditions. Despite no differences in relative water content (RWC) between the CV and the landraces under water deficit (WD), differences in leaf water potential (Ψ) defined the CV as having an isohydric control of stomata in contrast with anisohydric control for landraces. There was an identical decrease in the photosynthetic rate for all plants under stress, caused by both stomatal and non-stomatal limitations, namely, damages at the level of photosystem II as indicated by fluorescence measurements. Instantaneous water use efficiency (iWUE) was improved with stress in L1 and L3. Maintenance of higher relative chlorophyll content for longer periods in the CV revealed a stay-green phenotype. The slim differences observed in terms of stomatal control, iWUE and progression of senescence between the CV and the landraces under WD led to quite important differences in terms of productivity, as inferred from improved yield (number of pods and number of grains per plant). This is a clear result of pragmatic on-farm selection. On one hand it shows that small differences in stomatal responses or water saving strategies under WD may lead to desirable outcomes and should therefore be considered during breeding. On the other hand, it suggests that other traits could be explored in view of drought adaptation. These results highlight the need to preserve and characterize as many genetic pools as possible within a species.

5.
Carbohydr Polym ; 266: 118116, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34044933

RESUMO

Hydrogels based on biopolymers like Gum Arabic (GA) usually show low applicability due to weak mechanical properties. To overcome this issue, (nano)fillers are utilized as reinforcing agents. Here, GA hydrogels were reinforced by chitin nanowhiskers (CtNWs, aspect ratio of 14) isolated from the biopolymer chitin through acid hydrolysis. Firstly, GA was chemically modified with glycidyl methacrylate (GMA), which allowed its crosslinking by free radical reactions. Next, hydrogel samples containing different concentrations of CtNWs (0-10 wt%) were prepared and fully characterized. Mechanical characterization revealed that 10 wt% of CtNWs promoted an increase of 44% in the Young's modulus and 96% the rupture force values compared to the pristine hydrogel. Overall, all nanocomposites were stiffer and more resistant to elastic deformation. Due to this feature, the swelling capacity of the nanocomposites decreased. GA hydrogel without CtNWs exhibited a swelling degree of 975%, whereas nanocomposites containing CtNWs exhibited swelling degrees under 725%.

6.
Int J Biol Macromol ; 180: 88-96, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33657414

RESUMO

Chitosan/chondroitin sulfate (CHT/CS) curcumin-charged hydrogels were prepared through polyelectrolytic complexation (PEC) following two methodologies (PEC-CUR and PEC-T-CUR) and were applied on apoptosis of HeLa, HT29 and PC3 cancer cells. PEC-T-CUR (ionic liquid (IL) mixed using ultraturrax homogenizer) results show to be far better than for PEC-CUR (IL mixed using magnetic stirring), with IC50 being improved 5.13 times to HeLa cancer cells (from 1675.2 to 326.7 µg mL-1). PECs produced by this methodology presented favorable characteristics, such as particle size, hydrophobicity, pH swelling. Beyond this, the IL was quantitatively recovered in both cases. CUR entrapment levels were hugely loaded into PEC at around 100%. Swelling, dissolution/degradation, and pHpzc assays showed that PECs may positively act in several environments, releasing the CUR, the CHT and CS as well. Characterization through FTIR, SEM, TEM, TGA, DSC, and WAXS confirmed CUR presence in both types of PECs, and cytotoxic studies showed the significant anticancer effects of CUR-containing PECs.


Assuntos
Antineoplásicos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Quitosana/química , Curcumina/química , Portadores de Fármacos/química , Hidrogéis/química , Líquidos Iônicos/química , Nanopartículas/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sulfatos de Condroitina/química , Células HT29 , Células HeLa , Humanos , Hidrogéis/farmacologia , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Células PC-3 , Tamanho da Partícula , Polieletrólitos/química
7.
Carbohydr Res ; 499: 108194, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33234262

RESUMO

Strategies for incorporating water-insoluble photosensitisers (PS) in drug delivery systems have been extensively studied. In this work, we evaluate the formation, characterisation, drug sorption studies, and cytotoxicity of chitosan (CHT)/chondroitin sulphate (CS) polyelectrolyte complexes (PECs) coated with polystyrene-block-poly(acrylic acid) (PS-b-PAA) nanoparticles (NPs) loaded with chloroaluminum phthalocyanine (AlClPc). The PECs were characterised by infrared spectroscopy (FTIR), differential scanning calorimetric (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The PS-b-PAA NPs on the PEC surface was confirmed by scanning electron microscopy (SEM). Additionally, optical images distinguished the PEC structures containing PS-b-PAA or PS-b-PAA/AlClPc from the unloaded PEC. Kinetic and equilibrium studies investigate the sorption capacity of the PEC/PS-b-PAA toward AlClPc. The encapsulation efficiency reached 95% at 190 µg mL-1 AlClPc after only 15 min. The Brunauer-Emmett-Teller (BET) isotherm and pseudo-second-order kinetic fitted well to the experimental data. The PS-b-PAA NPs on the PEC surfaces increase the AlClPc bioavailability and the PEC structure stabilizes the PS-b-PAA/AlClPc nanostructures. The materials were cytocompatible upon healthy VERO (kidney epithelial cells), and cytotoxic against colorectal cancerous cells (HT-29 cells). For the first time, we associate PS-b-PAA/AlClPc with a hydrophilic and cytocompatible polysaccharide matrix. We suggest the use of these materials in strategies to treat cancer by using photodynamic therapy.


Assuntos
Antineoplásicos/farmacologia , Materiais Biocompatíveis/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Polieletrólitos/farmacologia , Polissacarídeos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Configuração de Carboidratos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/patologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Tamanho da Partícula , Polieletrólitos/síntese química , Polieletrólitos/química , Polissacarídeos/síntese química , Polissacarídeos/química
8.
Int J Mol Sci ; 21(22)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33212884

RESUMO

Pectin and chitosan films containing glycerol (Gly) at 5, 10, 15, 20, 30, and 40 wt % were prepared in an aqueous HCl solution (0.10 M) by the solvent evaporation method. The unwashed film (UF) containing 40 wt % Gly (UF40) had elongation at break (ε, %) of 19%. Washed films (WFs) had high tensile strength (σ > 46 MPa) and low elongation at break (ε, <5.0%), enabling their use in food packaging applications. The polymers' self-assembling occurred during the washing, increasing the stiffness. The XPS analysis suggests that some HCl is lost during the drying process, resulting in a low acid content on the UF surfaces. The UF40 (at 5.0 mg/mL) exhibits cytocompatibility toward mammalian cells and antimicrobial and anti-adhesive properties against Escherichia coli. The remaining HCl in the UF40 can be a disadvantage for food packaging applications; the UF40 (∅ = 8.5 mm; 55 µm thickness) releases H3O+/HCl, reducing the pH to approximately 3.0 when kept in 200 mL distilled water for approximately 30 min. Therefore, we propose the use of UF40 to coat commercial food packaging. The UF40 has low permeability to water vapor and oxygen and works as a barrier against ultraviolet light. The UF40 is also colorless and completely transparent. The UF40 maintained tomatoes' structural integrity for 18 days at room temperature with no oxidation or microorganism contamination. This paper presents a critical viewpoint concerning chitosan-based films with antimicrobial activities.


Assuntos
Antibacterianos/química , Quitosana/química , Materiais Revestidos Biocompatíveis/química , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos , Glicerol/química , Membranas Artificiais , Pectinas/química
9.
Int J Biol Macromol ; 152: 77-89, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32092423

RESUMO

To obtain pectin-based films is challenging due to the aqueous instability of polyelectrolyte mixtures. We overcome this issue by blending chitosan to pectin of high O-methoxylation degree (56%), followed by solvent evaporation. A durable film containing 74 wt% pectin content was produced and used as an adsorbent material toward Cu(II) ions. Kinetic and adsorption equilibrium studies showed that the pseudo-second-order and Sips isotherm models adjusted well to the experimental data, respectively. Langmuir isotherm indicated a maximum adsorption capacity (qm) for Cu(II) removal of 29.20 mg g-1. Differential scanning calorimetry, contact angle measurements, and X-ray photoelectron spectroscopy confirm the adsorption. The chemisorption plays an essential role in the process; thereby, the film reusability is low. After adsorption, the cytocompatible film/Cu(II) pair prevents the proliferation of Escherichia coli.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Cobre/química , Cobre/isolamento & purificação , Pectinas/química , Pectinas/farmacologia , Água/química , Adsorção , Quitosana/química , Escherichia coli/efeitos dos fármacos , Cinética , Teste de Materiais , Metilação , Soluções
10.
Carbohydr Polym ; 170: 99-106, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28522008

RESUMO

[Hmim][HSO4] ionic liquid (IL) and bio-renewable sources as chitosan (CHT) and chondroitin sulfate (CS) were used to yield hydrogel-based materials (CHT/CS). The use of IL to solubilize both polysaccharides was considered an innovative way based on "green chemistry" principle, aiming the production of CHT/CS blended systems. CHT/CS hydrogels were carried out in homogeneous medium from short dissolution times. The hydrogels were characterized and achieved with excellent stabilities (in the 1.2-10pH range), larger swelling capacities, as well as devoid of cytotoxicity towards the normal VERO and diseased HT29 cells. The CHT/CS hydrogels carried out in [Hmim][HSO4] could be applied in many technological purposes, like medical, pharmaceutical, and environmental fields.


Assuntos
Quitosana/química , Sulfatos de Condroitina/química , Hidrogéis/síntese química , Líquidos Iônicos/química , Sobrevivência Celular/efeitos dos fármacos , Células HT29 , Humanos , Hidrogéis/toxicidade
11.
Int J Biol Macromol ; 87: 237-45, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26930578

RESUMO

Nanoparticles (NPs) based on N,N-dimethyl chitosan (DMC) and N,N,N-trimethyl chitosan (TMC), physical crosslinked with sodium tripolyphosphate (TPP) were successful obtained, using water/benzyl alcohol emulsion system. NPs morphologies were evaluated by Scanning Electron Microscopy and Transmission Electron Microscopy. NPs were characterized by Infrared Spectroscopy (FTIR), Thermogravimetric Analysis, Zeta Potential, Differential Scanning Calorimetry and Wide-angle X-ray Scattering. Curcumin (CUR) was loaded onto NPs and controlled release studies were evaluated in simulated intestinal fluid and in simulated gastric fluid. Cytotoxicity assays showed only loaded TMC/TPP particles containing CUR were slightly cytotoxic on human cervical tumor cells (SiHa cells), concerning unloaded TMC/TPP particles. Conversely, loaded NPs (TMC/TPP/CUR and DMC/TPP/CUR), especially TMC/TPP/CUR sample presented greater biocompatibility toward healthy VERO cells than unloaded NPs (TMC/TPP and DMC/TPP).


Assuntos
Quitosana/química , Quitosana/toxicidade , Curcumina/química , Portadores de Fármacos/química , Portadores de Fármacos/toxicidade , Nanopartículas , Animais , Chlorocebus aethiops , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Humanos , Temperatura , Células Vero
12.
Plant Signal Behav ; 8(12): e26626, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24084646

RESUMO

Carbon signaling can override carbon supply in the regulation of growth. At least some of this regulation is imparted by the sugar signal trehalose 6-phosphate (T6P) through the protein kinase, SnRK1. This signaling pathway regulates biosynthetic processes involved in growth under optimal growing conditions. Recently, using a seedling system we showed that under sub-optimal conditions, such as cold, carbon signaling by T6P/ SnRK1 enables recovery of growth following relief of the stress. The T6P/ SnRK1 mechanism thus could be selected as a means of improving low temperature tolerance. High-throughput automated Fv/Fm measurements provide a potential means to screen for T6P/ SnRK1, and here we confirm through measurements of Fv/Fm in rosettes that T6P promotes low temperature tolerance and recovery during cold to warm transfer. Further, to better understand the coordination between sugars, trehalose pathway, and temperature-dependent growth, we examine the interrelationship between sugars, trehalose phosphate synthase (TPS), and trehalose phosphate phosphatase (TPP) gene expression and T6P content in seedlings. Sucrose, particularly when fed exogenously, correlated well with TPS1 and TPPB gene expression, suggesting that these enzymes are involved in maintaining carbon flux through the pathway in relation to sucrose supply. However, when sucrose accumulated to higher levels under low temperature and low N, TPS1 and TPPB expression were less directly related to sucrose; other factors may also contribute to regulation of TPS1 and TPPB expression under these conditions. TPPA expression was not related to sucrose content and all genes were not well correlated with endogenous glucose. Our work has implications for understanding acclimation to sink-limited growth conditions such as low temperature and for screening cold-tolerant genotypes with altered T6P/ SnRK1 signaling.


Assuntos
Temperatura Baixa , Redes e Vias Metabólicas/efeitos dos fármacos , Desenvolvimento Vegetal/efeitos dos fármacos , Sacarose/farmacologia , Trealose/metabolismo , Fluorescência , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Redes e Vias Metabólicas/genética , Desenvolvimento Vegetal/genética , Fosfatos Açúcares , Trealose/análogos & derivados
13.
Plant Physiol ; 162(3): 1720-32, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23735508

RESUMO

Trehalose 6-P (T6P) is a sugar signal in plants that inhibits SNF1-related protein kinase, SnRK1, thereby altering gene expression and promoting growth processes. This provides a model for the regulation of growth by sugar. However, it is not known how this model operates under sink-limited conditions when tissue sugar content is uncoupled from growth. To test the physiological importance of this model, T6P, SnRK1 activities, sugars, gene expression, and growth were measured in Arabidopsis (Arabidopsis thaliana) seedlings after transfer to cold or zero nitrogen compared with sugar feeding under optimal conditions. Maximum in vitro activities of SnRK1 changed little, but T6P accumulated up to 55-fold, correlating with tissue Suc content in all treatments. SnRK1-induced and -repressed marker gene expression strongly related to T6P above and below a threshold of 0.3 to 0.5 nmol T6P g(-1) fresh weight close to the dissociation constant (4 µm) of the T6P/ SnRK1 complex. This occurred irrespective of the growth response to Suc. This implies that T6P is not a growth signal per se, but through SnRK1, T6P primes gene expression for growth in response to Suc accumulation under sink-limited conditions. To test this hypothesis, plants with genetically decreased T6P content and SnRK1 overexpression were transferred from cold to warm to analyze the role of T6P/SnRK1 in relief of growth restriction. Compared with the wild type, these plants were impaired in immediate growth recovery. It is concluded that the T6P/SnRK1 signaling pathway responds to Suc induced by sink restriction that enables growth recovery following relief of limitations such as low temperature.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Fosfatos Açúcares/metabolismo , Trealose/análogos & derivados , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Metabolismo dos Carboidratos , Carboidratos , Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Nitrogênio , Plantas Geneticamente Modificadas , Proteínas Serina-Treonina Quinases/genética , Plântula , Sacarose/metabolismo , Sacarose/farmacologia , Trealose/metabolismo
14.
Plant Physiol Biochem ; 63: 89-98, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23257075

RESUMO

SnRK1 of the SNF1/AMPK group of protein kinases is an important regulatory protein kinase in plants. SnRK1 was recently shown as a target of the sugar signal, trehalose 6-phosphate (T6P). Glucose 6-phosphate (G6P) can also inhibit SnRK1 and given the similarity in structure to T6P, we sought to establish if each could impart distinct inhibition of SnRK1. Other central metabolites, glucose 1-phosphate (G1P), fructose 6-phosphate and UDP-glucose were also tested, and additionally ribose 5-phosphate (R5P), recently reported to inhibit SnRK1 strongly in wheat grain tissue. For the metabolites that inhibited SnRK1, kinetic models show that T6P, G1P and G6P each provide distinct regulation (50% inhibition of SnRK1 at 5.4 µM, 480 µM, >1 mM, respectively). Strikingly, G1P in combination with T6P inhibited SnRK1 synergistically. R5P, in contrast to the other inhibitors, inhibited SnRK1 in green tissues only. We show that this is due to consumption of ATP in the assay mediated by phosphoribulokinase during conversion of R5P to ribulose-1,5-bisphosphate. The accompanying loss of ATP limits the activity of SnRK1 giving rise to an apparent inhibition of SnRK1. Inhibition of SnRK1 by R5P in wheat grain preparations can be explained by the presence of green pericarp tissue; this exposes an important caveat in the assessment of potential protein kinase inhibitors. Data provide further insight into the regulation of SnRK1 by metabolites.


Assuntos
Glucofosfatos/farmacologia , Proteínas de Plantas/metabolismo , Fosfatos Açúcares/farmacologia , Trealose/análogos & derivados , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas Quinases/metabolismo , Ribulosefosfatos/metabolismo , Trealose/farmacologia , Triticum/efeitos dos fármacos , Triticum/metabolismo
15.
Plant Physiol ; 156(1): 373-81, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21402798

RESUMO

Trehalose 6-phosphate (T6P) is a sugar signal that regulates metabolism, growth, and development and inhibits the central regulatory SNF1-related protein kinase1 (SnRK1; AKIN10/AKIN11). To better understand the mechanism in wheat (Triticum aestivum) grain, we analyze T6P content and SnRK1 activities. T6P levels changed 178-fold 1 to 45 d after anthesis (DAA), correlating with sucrose content. T6P ranged from 78 nmol g(-1) fresh weight (FW) pregrain filling, around 100-fold higher than previously reported in plants, to 0.4 nmol g(-1) FW during the desiccation stage. In contrast, maximum SnRK1 activity changed only 3-fold but was inhibited strongly by T6P in vitro. To assess SnRK1 activity in vivo, homologs of SnRK1 marker genes in the wheat transcriptome were identified using Wheat Estimated Transcript Server. SnRK1-induced and -repressed marker genes were expressed differently pregrain filling compared to grain filling consistent with changes in T6P. To investigate this further maternal and filial tissues were compared pre- (7 DAA) and during grain filling (17 DAA). Strikingly, in vitro SnRK1 activity was similar in all tissues in contrast to large changes in tissue distribution of T6P. At 7 DAA T6P was 49 to 119 nmol g(-1) FW in filial and maternal tissues sufficient to inhibit SnRK1; at 17 DAA T6P accumulation was almost exclusively endospermal (43 nmol g(-1) FW) with 0.6 to 0.8 nmol T6P g(-1) FW in embryo and pericarp. The data show a correlation between T6P and sucrose overall that belies a marked effect of tissue type and developmental stage on T6P content, consistent with tissue-specific regulation of SnRK1 by T6P in wheat grain.


Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas Serina-Treonina Quinases/metabolismo , Sementes/metabolismo , Sacarose/metabolismo , Fosfatos Açúcares/metabolismo , Trealose/análogos & derivados , Triticum/metabolismo , Sequência de Aminoácidos , Biologia Computacional , Regulação da Expressão Gênica no Desenvolvimento , Dados de Sequência Molecular , Especificidade de Órgãos , Plantas Geneticamente Modificadas , Proteínas Serina-Treonina Quinases/genética , Sementes/genética , Sementes/crescimento & desenvolvimento , Sacarose/análise , Fosfatos Açúcares/análise , Trealose/análise , Trealose/metabolismo , Triticum/genética , Triticum/crescimento & desenvolvimento
16.
Field methods ; 23(4): 379-396, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29081719

RESUMO

This article summarizes the work of the Comparative Cognitive Testing Workgroup, an international coalition of survey methodologists interested in developing an evidence-based methodology for examining the comparability of survey questions within cross-cultural or multinational contexts. To meet this objective, it was necessary to ensure that the cognitive interviewing (CI) method itself did not introduce method bias. Therefore, the workgroup first identified specific characteristics inherent in CI methodology that could undermine the comparability of CI evidence. The group then developed and implemented a protocol addressing those issues. In total, 135 cognitive interviews were conducted by participating countries. Through the process, the group identified various interpretive patterns resulting from sociocultural and language-related differences among countries as well as other patterns of error that would impede comparability of survey data.

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