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1.
World J Gastrointest Oncol ; 16(2): 386-397, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38425396

RESUMO

BACKGROUND: The prognostic value of the Systemic Inflammation Response Index (SIRI) in advanced pancreatic cancer is recognized, but its correlation with patients´ nutritional status and outcomes remains unexplored. AIM: To study the prognostic significance of SIRI and weight loss in metastatic pancreatic cancer. METHODS: The PANTHEIA-Spanish Society of Medical Oncology (SEOM) study is a multicentric (16 Spanish hospitals), observational, longitudinal, non-interventional initiative, promoted by the SEOM Real World-Evidence work group. This pilot study sought to analyze the association between weight loss and inflammatory status as defined by SIRI. The cohort stems from a proof-of-concept pilot study conducted at one of the coordinating centers. Patients with pathologically confirmed metastatic pancreatic adenocarcinoma, treated from January 2020 to January 2023, were included. The index was calculated using the product of neutrophil and monocyte counts, divided by lymphocyte counts, obtained within 15 days before initiation chemotherapy. This study evaluated associations between overall survival (OS), SIRI and weight loss. RESULTS: A total of 50 patients were included. 66% of these patients were male and the median age was 66 years. Metastasis sites: 36% liver, 12% peritoneal carcinomatosis, 10% lung, and 42% multiple locations. Regarding the first line palliative chemotherapy treatments: 50% received gemcitabine plus nab-paclitaxel; 28%, modified fluorouracil, leucovorin, irinotecan and oxaliplatin, and 16% were administered gemcitabine. 42% had a weight loss > 5% in the three months (mo) preceding diagnosis. 21 patients with a SIRI ≥ 2.3 × 103/L exhibited a trend towards a lower median OS compared to those with a SIRI < 2.3 × 103/L (4 vs 18 mo; P < 0.000). Among 21 patients with > 5% weight loss before diagnosis, the median OS was 6 mo, in contrast to 19 mo for those who did not experience such weight loss (P = 0.003). Patients with a weight loss > 5% showed higher SIRI levels. This difference was statistically significant (P < 0.000). For patients with a SIRI < 2.3 × 103/L, those who did not lose > 5% of their weight had an OS of 20 mo, compared to 11 mo for those who did (P < 0.001). No association was found between carbohydrate antigen 19-9 levels ≥ 1000 U/mL and weight loss. CONCLUSION: A higher SIRI was correlated with decreased survival rates in patients with metastatic pancreatic cancer and associated with weight loss. An elevated SIRI is suggested as a predictor of survival, emphasizing the need for prospective validation in the upcoming PANTHEIA-SEOM study.

2.
Food Energy Secur ; 12(1): e435, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37035025

RESUMO

The growing world population and global increases in the standard of living both result in an increasing demand for food, feed and other plant-derived products. In the coming years, plant-based research will be among the major drivers ensuring food security and the expansion of the bio-based economy. Crop productivity is determined by several factors, including the available physical and agricultural resources, crop management, and the resource use efficiency, quality and intrinsic yield potential of the chosen crop. This review focuses on intrinsic yield potential, since understanding its determinants and their biological basis will allow to maximize the plant's potential in food and energy production. Yield potential is determined by a variety of complex traits that integrate strictly regulated processes and their underlying gene regulatory networks. Due to this inherent complexity, numerous potential targets have been identified that could be exploited to increase crop yield. These encompass diverse metabolic and physical processes at the cellular, organ and canopy level. We present an overview of some of the distinct biological processes considered to be crucial for yield determination that could further be exploited to improve future crop productivity.

3.
Front Plant Sci ; 14: 1134170, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36993845

RESUMO

Compared to C3 species, C4 plants showed higher photosynthetic capacity as well as water and nitrogen use efficiency due to the presence of the C4 photosynthetic pathway. Previous studies have shown that all genes required for the C4 photosynthetic pathway exist in the genomes of C3 species and are expressed. In this study, the genes encoding six key C4 photosynthetic pathway enzymes (ß-CA, PEPC, ME, MDH, RbcS, and PPDK) in the genomes of five important gramineous crops (C4: maize, foxtail millet, and sorghum; C3: rice and wheat) were systematically identified and compared. Based on sequence characteristics and evolutionary relationships, their C4 functional gene copies were distinguished from non-photosynthetic functional gene copies. Furthermore, multiple sequence alignment revealed important sites affecting the activities of PEPC and RbcS between the C3 and C4 species. Comparisons of expression characteristics confirmed that the expression patterns of non-photosynthetic gene copies were relatively conserved among species, while C4 gene copies in C4 species acquired new tissue expression patterns during evolution. Additionally, multiple sequence features that may affect C4 gene expression and subcellular localization were found in the coding and promoter regions. Our work emphasized the diversity of the evolution of different genes in the C4 photosynthetic pathway and confirmed that the specific high expression in the leaf and appropriate intracellular distribution were the keys to the evolution of C4 photosynthesis. The results of this study will help determine the evolutionary mechanism of the C4 photosynthetic pathway in Gramineae and provide references for the transformation of C4 photosynthetic pathways in wheat, rice, and other major C3 cereal crops.

5.
BMC Psychiatry ; 22(1): 400, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35705927

RESUMO

BACKGROUND: Financial distress is thought to be a key reason why small-medium enterprise (SME) owners experience higher levels of mental health conditions compared with the broader population. Business advisors who form trusting, high-quality relationships with their SME clients, are therefore well placed to: (1) help prevent/reduce key sources of financial distress, (2) better understand the business and personal needs of their clients and, (3) recognise the signs and symptoms of mental health conditions and encourage help-seeking where appropriate. The aim of this study is to compare the effectiveness of relationship building training (RBT) combined with mental health first aid (MHFA) training for business advisors with MHFA alone, on the financial and mental health of their SME-owner clients. METHODS: This is a single blind, two-arm randomised controlled trial. Participants will be business advisors who provide information, guidance and/or assistance to SME owner clients and are in contact with them at least 3 times a year. The business advisors will invite their SME-owner clients to complete 3 online surveys at baseline, 6- and 12-months. Business advisors will be randomised to one of two conditions, using a 1:1 allocation ratio: (1) MHFA with RBT; or (2) MHFA alone, and complete 3 online surveys at baseline, 2- and 6-months. Primary outcomes will be measured in the business advisors and consist of the quality of the relationship, stigmatizing attitude, confidence to offer mental health first aid, quality of life and provision of mental health first aid. Secondary outcomes will be measured in the SME owners and includes trust in their business advisors, the quality of this relationship, financial wellbeing, financial distress, psychological distress, help-seeking behaviour, and quality of life. To complement the quantitative data, we will include a qualitative process evaluation to examine what contextual factors impacted the reach, effectiveness, adoption, implementation, and maintenance of the training. DISCUSSION: As there is evidence for the connections between client trust, quality of relationship and financial and mental wellbeing, we hypothesise that the combined RBT and MHFA training will lead to greater improvements in these outcomes in SME owners compared with MHFA alone. TRIAL REGISTRATION: ClinicalTrials.gov : NCT04982094 . Retrospectively registered 29/07/2021. The study started in February 2021 and the recruitment is ongoing.


Assuntos
Letramento em Saúde , Saúde Mental , Humanos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Método Simples-Cego , Confiança
6.
Nat Plants ; 8(2): 118-124, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35058608

RESUMO

Cowpea is the major source of vegetable protein for rural populations in sub-Saharan Africa and average yields are not keeping pace with population growth. Each day, crop leaves experience many shade events and the speed of photosynthetic adjustment to this dynamic environment strongly affects daily carbon gain. Rubisco activity is particularly important because it depends on the speed and extent of deactivation in shade and recovers slowly on return to sun. Here, direct biochemical measurements showed a much faster rate of Rubisco deactivation in cowpea than prior estimates inferred from dynamics of leaf gas exchange in other species1-3. Shade-induced deactivation was driven by decarbamylation, and half-times for both deactivation in shade and activation in saturating light were shorter than estimates from gas exchange (≤53% and 79%, respectively). Incorporating these half-times into a model of diurnal canopy photosynthesis predicted a 21% diurnal loss of productivity and suggests slowing Rubisco deactivation during shade is an unexploited opportunity for improving crop productivity.


Assuntos
Ribulose-Bifosfato Carboxilase , Vigna , Dióxido de Carbono/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo
7.
Biology (Basel) ; 10(7)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34356545

RESUMO

The realization of the full objectives of international policies targeting global food security and climate change mitigation, including the United Nation's Sustainable Development Goals, the Paris Climate Agreement COP21 and the European Green Deal, requires that we (i) sustainably increase the yield, nutritional quality and biodiversity of major crop species, (ii) select climate-ready crops that are adapted to future weather dynamic and (iii) increase the resource use efficiency of crops for sustainably preserving natural resources. Ultimately, the grand challenge to be met by agriculture is to sustainably provide access to sufficient, nutritious and diverse food to a worldwide growing population, and to support the circular bio-based economy. Future-proofing our crops is an urgent issue and a challenging goal, involving a diversity of crop species in differing agricultural regimes and under multiple environmental drivers, providing versatile crop-breeding solutions within wider socio-economic-ecological systems. This goal can only be realized by a large-scale, international research cooperation. We call for international action and propose a pan-European research initiative, the CropBooster Program, to mobilize the European plant research community and interconnect it with the interdisciplinary expertise necessary to face the challenge.

8.
AJNR Am J Neuroradiol ; 42(9): 1591-1597, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34167960

RESUMO

BACKGROUND AND PURPOSE: The reliability of contrast-enhanced MRA in monitoring serial volumetric changes of unruptured intracranial aneurysms has not been established. We aimed to determine the coefficient of variance of contrast-enhanced MRA in measuring aneurysm volumes, thus establishing criteria for aneurysm growth and permitting identification of variables predictive of growth. MATERIALS AND METHODS: Aneurysm volumes were measured from serial contrast-enhanced MRA studies of patients with untreated intracranial aneurysms who underwent >2 sequential MR imaging evaluations. After coregistering all sequential studies in 3D space for each aneurysm and signal intensity normalization, aneurysm volume was determined across all time points. A linear mixed effects model was built to estimate the coefficient of variance of the measurement as well as to determine predictive variables. Growth was defined as relative growth exceeding 2 times the measurement coefficient of variance (sudden growth, as 4 times the coefficient of variance). RESULTS: A total of 95 patients with 112 aneurysms were included (5.9 scans during 4.0 years on average, 616 scan measurements in total). The coefficient of variance was 5.5% of the aneurysm volume, and the relative growth rate was dependent on the location: anterior cerebral artery, 4.52% per year; vertebral artery, 2.46% per year; middle cerebral artery, 2.74% per year; basilar artery, 2.36% per year; internal carotid artery, 1.14% per year. Thirty-six of 112 (32%) aneurysms were characterized as growing, and 11/36 of them had an episode of sudden growth. CONCLUSIONS: Volume measurement of unruptured intracranial aneurysms by contrast-enhanced MRA seems a reliable metric for tracking the growth trajectory of aneurysms. Furthermore, the aneurysm growth rate differs among different locations.


Assuntos
Aneurisma Intracraniano , Artéria Carótida Interna , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Reprodutibilidade dos Testes
9.
Clin. transl. oncol. (Print) ; 23(6): 1034-1046, jun. 2021. tab
Artigo em Inglês | IBECS | ID: ibc-221324

RESUMO

Venous thromboembolic disease (VTED) is a common and clinically important complication in patients with cancer, contributing to its mortality and morbidity. Direct oral anticoagulant agents (DOACs), including direct thrombin inhibitors and direct factor Xa inhibitors, are as effective as vitamin K antagonists for the treatment of VTED and are associated with less frequent and severe bleeding. They have advantages over low-molecular-weight heparin, but comparative long-term efficacy and safety data are lacking for these compounds. Recent randomized clinical trials suggest a role for DOACs in the treatment of VTED in patients with cancer. This review will discuss the existing evidence and future perspectives on the role of DOACs in the treatment of VTE based on the current evidence about their overall efficacy and safety and the limited information in patients with cancer; in addition, we will briefly review their pharmacokinetic properties with special reference to potential interactions (AU)


Assuntos
Anticoagulantes/uso terapêutico , Neoplasias/complicações , Tromboembolia/etiologia , Tromboembolia/prevenção & controle , Guias de Prática Clínica como Assunto
10.
Plant J ; 106(3): 876-887, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33576096

RESUMO

Photosynthetic inefficiencies limit the productivity and sustainability of crop production and the resilience of agriculture to future societal and environmental challenges. Rubisco is a key target for improvement as it plays a central role in carbon fixation during photosynthesis and is remarkably inefficient. Introduction of mutations to the chloroplast-encoded Rubisco large subunit rbcL is of particular interest for improving the catalytic activity and efficiency of the enzyme. However, manipulation of rbcL is hampered by its location in the plastome, with many species recalcitrant to plastome transformation, and by the plastid's efficient repair system, which can prevent effective maintenance of mutations introduced with homologous recombination. Here we present a system where the introduction of a number of silent mutations into rbcL within the model plant Nicotiana tabacum facilitates simplified screening via additional restriction enzyme sites. This system was used to successfully generate a range of transplastomic lines from wild-type N. tabacum with stable point mutations within rbcL in 40% of the transformants, allowing assessment of the effect of these mutations on Rubisco assembly and activity. With further optimization the approach offers a viable way forward for mutagenic testing of Rubisco function in planta within tobacco and modification of rbcL in other crops where chloroplast transformation is feasible. The transformation strategy could also be applied to introduce point mutations in other chloroplast-encoded genes.


Assuntos
Edição de Genes/métodos , Genes de Plantas/genética , Nicotiana/genética , Mutação Puntual/genética , Ribulose-Bifosfato Carboxilase/genética , Cloroplastos/genética , Ribulose-Bifosfato Carboxilase/metabolismo , Nicotiana/enzimologia
11.
Clin Transl Oncol ; 23(6): 1034-1046, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33206333

RESUMO

Venous thromboembolic disease (VTED) is a common and clinically important complication in patients with cancer, contributing to its mortality and morbidity. Direct oral anticoagulant agents (DOACs), including direct thrombin inhibitors and direct factor Xa inhibitors, are as effective as vitamin K antagonists for the treatment of VTED and are associated with less frequent and severe bleeding. They have advantages over low-molecular-weight heparin, but comparative long-term efficacy and safety data are lacking for these compounds. Recent randomized clinical trials suggest a role for DOACs in the treatment of VTED in patients with cancer. This review will discuss the existing evidence and future perspectives on the role of DOACs in the treatment of VTE based on the current evidence about their overall efficacy and safety and the limited information in patients with cancer; in addition, we will briefly review their pharmacokinetic properties with special reference to potential interactions.


Assuntos
Inibidores do Fator Xa/uso terapêutico , Neoplasias/complicações , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/prevenção & controle , Humanos , Guias de Prática Clínica como Assunto , Tromboembolia Venosa/etiologia
12.
Trends Biotechnol ; 39(5): 438-444, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33162172

RESUMO

Depending on how the future will unfold, today's progress in biotechnology research has greater or lesser potential to be the basis of subsequent innovation. Tracking progress against indicators for different future scenarios will help to focus, emphasize, or de-emphasize discovery research in a timely manner and to maximize the chance for successful innovation. In this paper, we show how learning scenarios with a 2050 time horizon help to recognize the implications of political and societal developments on the innovation potential of ongoing biotechnological research. We also propose a model to further increase open innovation between academia and the biotechnology value chain to help fundamental research explore discovery fields that have a greater chance to be valuable for applied research.


Assuntos
Biotecnologia , Biotecnologia/tendências
13.
Nat Plants ; 6(9): 1158-1166, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32868887

RESUMO

Rubisco sustains the biosphere through the fixation of CO2 into biomass. In plants and cyanobacteria, form I Rubisco is structurally comprised of large and small subunits, whereas all other Rubisco forms lack small subunits. The rise of the form I complex through the innovation of small subunits represents a key, yet poorly understood, transition in Rubisco's evolution. Through metagenomic analyses, we discovered a previously uncharacterized clade sister to form I Rubisco that evolved without small subunits. This clade diverged before the evolution of cyanobacteria and the origin of the small subunit; thus, it provides a unique reference point to advance our understanding of form I Rubisco evolution. Structural and kinetic data presented here reveal how a proto-form I Rubisco assembled and functioned without the structural stability imparted from small subunits. Our findings provide insight into a key evolutionary transition of the most abundant enzyme on Earth and the predominant entry point for nearly all global organic carbon.


Assuntos
Cianobactérias/genética , Cianobactérias/metabolismo , Estrutura Molecular , Fotossíntese/genética , Fotossíntese/fisiologia , Fenômenos Fisiológicos Vegetais/genética , Ribulose-Bifosfato Carboxilase/genética , Ribulose-Bifosfato Carboxilase/metabolismo , Filogenia
15.
Clin Transl Oncol ; 22(11): 2026-2031, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32270416

RESUMO

BACKGROUND: There are conflicting data regarding the role of KRAS mutation on the risk of venous thromboembolism (VTE) in colorectal cancer (CRC) patients. Moreover, the role of other biomarkers such as NRAS or BRAF has not been studied. PURPOSE: To analyze the incidence of VTE in a cohort of patients with CRC based on KRAS, NRAS, and BRAF status. METHODS: We performed a retrospective review of patients with unresectable locally advanced and metastatic CRC (mCRC) and known KRAS/NRAS/BRAF status, attended in the Medical Oncology Department of the Hospital General Universitario Gregorio Marañón (Madrid, Spain). The primary outcome was VTE defined as any venous thromboembolic event that occurred either 6 months before or at any time after the diagnosis of CRC. The biomarker status (KRAS, NRAS, and BRAF) and other predictors of thrombosis were collected. RESULTS: One hundred and ninety-four patients were identified and included in the analysis. Forty-one patients (21.1%) experienced VTE. The incidence was 19.1% in RAS-mutated patients, 28.6% in BRAF-mutated patients and 21% in triple wild-type patients (p = NS). In multivariate analysis, ECOG ≥ 2 was the only independent predictor of VTE (OR 8.73; CI 95% 1.32-57.82; p = 0.025). CONCLUSIONS: In our study, biomarkers have not been associated with an increased risk of VTE in CRC patients. A high incidence of VTE in BRAF-mutated patients has been observed and should be explored in further studies.


Assuntos
Neoplasias Colorretais/genética , GTP Fosfo-Hidrolases/genética , Proteínas de Membrana/genética , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Tromboembolia Venosa/epidemiologia , Idoso , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tromboembolia Venosa/etiologia
16.
J Exp Bot ; 71(7): 2219-2225, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32060550

RESUMO

This perspective summarizes the presentations and discussions at the ' International Symposium on Synthetic Biology in Photosynthesis Research', which was held in Shanghai in 2018. Leveraging the current advanced understanding of photosynthetic systems, the symposium brain-stormed about the redesign and engineering of photosynthetic systems for translational goals and evaluated available new technologies/tools for synthetic biology as well as technological obstacles and new tools that would be needed to overcome them. Four major research areas for redesigning photosynthesis were identified: (i) mining natural variations of photosynthesis; (ii) coordinating photosynthesis with pathways utilizing photosynthate; (iii) reconstruction of highly efficient photosynthetic systems in non-host species; and (iv) development of new photosynthetic systems that do not exist in nature. To expedite photosynthesis synthetic biology research, an array of new technologies and community resources need to be developed, which include expanded modelling capacities, molecular engineering toolboxes, model species, and phenotyping tools.


Assuntos
Fotossíntese , Biologia Sintética , China
17.
Clin Transl Oncol ; 22(2): 171-186, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31981080

RESUMO

In 2011, the Spanish Society of Medical Oncology (SEOM) first published a clinical guideline of venous thromboembolism (VTE) and cancer. This guideline was updated in 2014, and since then, multiple studies and clinical trials have changed the landscape of the treatment and prophylaxis of VTE in cancer patients. To incorporate the most recent evidence, including data from direct oral anticoagulants (DOACs) randomized clinical trials, SEOM presents a new update of the guideline.


Assuntos
Ensaios Clínicos como Assunto/normas , Neoplasias/terapia , Guias de Prática Clínica como Assunto/normas , Tromboembolia Venosa/terapia , Humanos , Sociedades Médicas
18.
Phys Rev Lett ; 125(24): 247703, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33412043

RESUMO

Intermediate band solar cells (IBSCs) promise high efficiencies while maintaining a low device structural complexity. A high efficiency can be obtained by harvesting below-band-gap photons, thus increasing the current, while at the same time preserving a high voltage. Here, we provide experimental proof that below-band-gap photons can be used to produce nonzero electrical work in an IBSC without compromising the voltage. For this, we manufacture a GaSb/GaAs quantum-dot IBSC. We use light biasing and make our cell operate at the maximum power point at 9 K. We measure the photocurrent response to absorption of photons with an energy of less than 1.15 eV while the cell is operating at 1.15 V. We also show that this result implies the existence of three quasi-Fermi levels linked to the three electronic bands in our device, as demanded by the IBSC theory to preserve the output voltage of the cell.

19.
Clin Transl Oncol ; 22(8): 1312-1320, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31863355

RESUMO

OBJECTIVE: To analyze the relationship between therapeutic (weight-adjusted) dose of bemiparin and anti-Xa activity in patients with venous thromboembolism (VTE) and cancer in comparison with a cohort of patients with VTE without cancer, and its relationship with outcomes. MATERIALS AND METHODS: This is a prospective cohort study that comprised a cohort of patients with cancer-associated VTE and a cohort of non-cancer patients with VTE, all of them treated with bemiparin. The ethics committee approved the study and informed consent was obtained from the patients. RESULTS: One hundred patients were included (52 with cancer and 48 without cancer), with a median follow-up of 9.8 months. Mean anti-Xa activity was 0.89 (± 0.33) UI/mL in oncological patients and 0.83 (± 0.30) UI/mL in non-cancer patients (mean difference - 0.05 95% CI - 0.18; 0.06). A multiple linear regression model showed that anti-Xa peak was associated with the dose/kg independently of possible confounding variables (presence of cancer, age, sex and eGFR-estimated Glomerular Filtration Rate), in a way that for every 1 UI of dose/kg increase, the anti-Xa peak activity increased 0.006 UI/mL (95% CI 0.003; 0.009) (p < 0.001). The predictive capacity of anti-Xa peak in the oncology cohort showed an area under the ROC curve of 0.46 (95% CI 0.24-0.68), 0.70 (95% CI 0.49-0.91) and 0.74 (95% CI 0.44-0.94) for death, first bleeding and recurrence of VTE, respectively, and none was statistically significant. CONCLUSION: In patients with venous thromboembolism treated with bemiparin, anti-Xa levels were not influenced by the presence of cancer.


Assuntos
Anticoagulantes/uso terapêutico , Inibidores do Fator Xa/sangue , Heparina de Baixo Peso Molecular/uso terapêutico , Neoplasias/complicações , Tromboembolia Venosa/sangue , Idoso , Anticoagulantes/efeitos adversos , Feminino , Hemorragia/induzido quimicamente , Heparina de Baixo Peso Molecular/efeitos adversos , Humanos , Modelos Lineares , Masculino , Neoplasias/sangue , Estudos Prospectivos , Insuficiência Renal/diagnóstico , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/etiologia
20.
Plant Physiol ; 182(2): 807-818, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31744936

RESUMO

Much of the research aimed at improving photosynthesis and crop productivity attempts to overcome shortcomings of the primary CO2-fixing enzyme Rubisco. Cyanobacteria utilize a CO2-concentrating mechanism (CCM), which encapsulates Rubisco with poor specificity but a relatively fast catalytic rate within a carboxysome microcompartment. Alongside the active transport of bicarbonate into the cell and localization of carbonic anhydrase within the carboxysome shell with Rubisco, cyanobacteria are able to overcome the limitations of Rubisco via localization within a high-CO2 environment. As part of ongoing efforts to engineer a ß-cyanobacterial CCM into land plants, we investigated the potential for Rubisco large subunits (LSU) from the ß-cyanobacterium Synechococcus elongatus (Se) to form aggregated Rubisco complexes with the carboxysome linker protein CcmM35 within tobacco (Nicotiana tabacum) chloroplasts. Transplastomic plants were produced that lacked cognate Se Rubisco small subunits (SSU) and expressed the Se LSU in place of tobacco LSU, with and without CcmM35. Plants were able to form a hybrid enzyme utilizing tobacco SSU and the Se LSU, allowing slow autotrophic growth in high CO2 CcmM35 was able to form large Rubisco aggregates with the Se LSU, and these incorporated small amounts of native tobacco SSU. Plants lacking the Se SSU showed delayed growth, poor photosynthetic capacity, and significantly reduced Rubisco activity compared with both wild-type tobacco and lines expressing the Se SSU. These results demonstrate the ability of the Se LSU and CcmM35 to form large aggregates without the cognate Se SSU in planta, harboring active Rubisco that enables plant growth, albeit at a much slower pace than plants expressing the cognate Se SSU.


Assuntos
Processos Autotróficos/genética , Dióxido de Carbono/metabolismo , Nicotiana/enzimologia , Nicotiana/genética , Fotossíntese/genética , Melhoramento Vegetal/métodos , Ribulose-Bifosfato Carboxilase/genética , Synechococcus/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Ciclo do Carbono/genética , Ciclo do Carbono/fisiologia , Cloroplastos/genética , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Microscopia Eletrônica de Transmissão , Organelas/metabolismo , Fotossíntese/fisiologia , Plantas Geneticamente Modificadas/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Synechococcus/metabolismo , Nicotiana/crescimento & desenvolvimento , Nicotiana/metabolismo
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