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1.
Artigo em Inglês | MEDLINE | ID: mdl-38427173

RESUMO

Reduction of the environmental impact, energy efficiency and optimization of material resources are basic aspects in the design and sizing of a battery. The objective of this study was to identify and characterize the environmental impact associated with the life cycle of a 7.47 Wh 18,650 cylindrical single-cell LiFePO4 battery. Life cycle assessment (LCA), the SimaPro 9.1 software package, the Ecoinvent 3.5 database and the ReCiPe 2016 impact assessment method were used for this purpose. Environmental impacts were modelled and quantified using the dual midpoint-endpoint approach and the "cradle-to-gate" model. The results showed the electrodes to be the battery components with the highest environmental impact (41.36% of the total), with the negative electrode being the most unfavourable (29.8 mPt). The ageing, calibration and testing process (53.97 mPt) accounts for 97.21% of the total impact associated with the production process's consumption of energy, and 41.20% of the total impact associated with the battery. This new knowledge will allow a more detailed view of the environmental impact of cylindrical cell LiFePO4 batteries, favouring the identification of critical points to enhance their sustainable production.

2.
Plant Cell Environ ; 47(5): 1503-1512, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38251436

RESUMO

d-amino acids are the d stereoisomers of the common l-amino acids found in proteins. Over the past two decades, the occurrence of d-amino acids in plants has been reported and circumstantial evidence for a role in various processes, including interaction with soil microorganisms or interference with cellular signalling, has been provided. However, examples are not numerous and d-amino acids can also be detrimental, some of them inhibiting growth and development. Thus, the persistence of d-amino acid metabolism in plants is rather surprising, and the evolutionary origins of d-amino acid metabolism are currently unclear. Systemic analysis of sequences associated with d-amino acid metabolism enzymes shows that they are not simply inherited from cyanobacterial metabolism. In fact, the history of plant d-amino acid metabolism enzymes likely involves multiple steps, cellular compartments, gene transfers and losses. Regardless of evolutionary steps, enzymes of d-amino acid metabolism, such as d-amino acid transferases or racemases, have been retained by higher plants and have not simply been eliminated, so it is likely that they fulfil important metabolic roles such as serine, folate or plastid peptidoglycan metabolism. We suggest that d-amino acid metabolism may have been critical to support metabolic functions required during the evolution of land plants.


Assuntos
Isomerases de Aminoácido , Embriófitas , Isomerases de Aminoácido/química , Isomerases de Aminoácido/genética , Isomerases de Aminoácido/metabolismo , Aminoácidos/metabolismo , Plantas/metabolismo , Embriófitas/metabolismo , Bactérias/metabolismo
3.
J Agric Food Chem ; 72(2): 1302-1320, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38175162

RESUMO

Inulin is widely used as a prebiotic and emerging as a priming compound to counteract plant diseases. We isolated inulin-degrading strains from the lettuce phyllosphere, identified as Bacillus subtilis and Priestia megaterium, species hosting well-known biocontrol organisms. To better understand their varying inulin degradation strategies, three intracellular ß-fructofuranosidases from P. megaterium NBRC15308 were characterized after expression in Escherichia coli: a predicted sucrose-6-phosphate (Suc6P) hydrolase (SacAP1, supported by molecular docking), an exofructanase (SacAP2), and an invertase (SacAP3). Based on protein multiple sequence and structure alignments of bacterial glycoside hydrolase family 32 enzymes, we identified conserved residues predicted to be involved in binding phosphorylated (Suc6P hydrolases) or nonphosphorylated substrates (invertases and fructanases). Suc6P hydrolases feature positively charged residues near the structural catalytic pocket (histidine, arginine, or lysine), whereas other ß-fructofuranosidases contain tryptophans. This correlates with our phylogenetic tree, grouping all predicted Suc6P hydrolases in a clan associated with genomic regions coding for transporters involved in substrate phosphorylation. These results will help to discriminate between Suc6P hydrolases and other ß-fructofuranosidases in future studies and to better understand the interaction of B. subtilis and P. megaterium endophytes with sucrose and/or fructans, sugars naturally present in plants or exogenously applied in the context of defense priming.


Assuntos
Inulina , Fosfatos Açúcares , beta-Frutofuranosidase , beta-Frutofuranosidase/genética , beta-Frutofuranosidase/metabolismo , Inulina/metabolismo , Filogenia , Simulação de Acoplamento Molecular , Glicosídeo Hidrolases/química , Sacarose/metabolismo , Bactérias/genética , Bactérias/metabolismo
4.
Carbohydr Polym ; 328: 121690, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38220320

RESUMO

World-wide, pathogenic fungi such as Botrytis cinerea cause tremendous yield losses in terms of food production and post-harvest food decay. Many fungi produce inulin-type oligosaccharides (IOSs) from inulin through endo-inulinases which typically show a two domain structure. B.cinerea lacks a two domain endo-inulinase but contains a three domain structure instead. Genome mining revealed three and four domain (d4) enzymes in the fungal kingdom. Here, three and two domain enzymes were compared in their capacity to produce IOSs from inulin. Hill kinetics were observed in three domain enzymes as compared to Michaelis-Menten kinetics in two domain enzymes, suggesting that the N-terminal extension functions as a carbohydrate binding module. Analysis of the IOS product profiles generated from purified GF6, GF12, GF16 and GF18 inulins and extensive sugar docking approaches led to enhanced insights in the active site functioning, revealing subtle differences between the endo-inulinases from Aspergillus niger and B. cinerea. Improved insights in structure-function relationships in fungal endo-inulinases offer opportunities to develop superior enzymes for the production of specific IOS formulations to improve plant and animal health (priming agents, prebiotics).


Assuntos
Inulina , Oligossacarídeos , Inulina/metabolismo , Oligossacarídeos/química , Glicosídeo Hidrolases/metabolismo , Botrytis/metabolismo , Aspergillus niger
5.
Methods Mol Biol ; 2759: 9-24, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38285135

RESUMO

Technological innovation in the design and manufacture of temporary immersion systems (TIS) has increased in the past decade. Innovations have involved the size, fitting, and replacement of components, as well as manufacturing materials. Air replacement by compressor has also been substituted by air replacement by preset tilting/rotation of culture bottles. This design modification aims to increase the biological yield (number of shoots) produced in these bottles and reduce manufacturing costs. However, the operative principle has remained unchanged through time: promote an environment where explant immersions in the culture medium are programmable. The changes in the TIS design involve advantages and disadvantages, generating the efficiency of one type over another. However, validation to identify the most effective type of TIS should be carried out for each plant species. This chapter lists the different types of temporary immersion available on the market, emphasizing the advantages and disadvantages of each when used for plant micropropagation.


Assuntos
Comércio , Imersão , Meios de Cultura , Rotação
6.
PLoS One ; 18(12): e0296510, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38157369

RESUMO

INTRODUCTION: Tissue engineering has emerged as an innovative approach to treat critical-size bone defects using biocompatible scaffolds, thus avoiding complex distraction surgeries or limited stock grafts. Continuous regeneration monitoring is essential in critical-size cases due to the frequent appearance of non-unions. This work evaluates the potential clinical use of gait analysis for the mechanical assessment of a tissue engineering regeneration as an alternative to the traditional and hardly conclusive manual or radiological follow-up. MATERIALS AND METHODS: The 15-mm metatarsal fragment of eight female merino sheep was surgically replaced by a bioceramic scaffold stabilized with an external fixator. Gait tests were performed weekly by making the sheep walk on an instrumented gangway. The evolution of different kinematic and dynamic parameters was analyzed for all the animal's limbs, as well as asymmetries between limbs. Finally, potential correlation in the recovery of the gait parameters was evaluated through the linear regression models. RESULTS: After surgery, the operated limb has an altered way of carrying body weight while walking. Its loading capacity was significantly reduced as the stance phases were shorter and less impulsive. The non-operated limbs compensated for this mobility deficit. All parameters were normalizing during the consolidation phase while the bone callus was simultaneously mineralizing. The results also showed high levels of asymmetry between the operated limb and its contralateral, which exceeded 150% when analyzing the impulse after surgery. Gait recovery significantly correlated between symmetrical limbs. CONCLUSIONS: Gait analysis was presented as an effective, low-cost tool capable of mechanically predicting the regeneration of critical-size defects treated by tissue engineering, as comparing regeneration processes or novel scaffolds. Despite the progressive normalization as the callus mineralized, the bearing capacity reduction and the asymmetry of the operated limb were more significant than in other orthopedic alternatives.


Assuntos
Regeneração Óssea , Engenharia Tecidual , Feminino , Ovinos , Animais , Marcha , Calo Ósseo , Caminhada , Alicerces Teciduais
7.
Tissue Eng Regen Med ; 20(6): 893-904, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37606809

RESUMO

BACKGROUND: 3D-printed bioceramic scaffolds have gained popularity due to their controlled microarchitecture and their proven biocompatibility. However, their high brittleness makes their surgical implementation complex for weight-bearing bone treatments. Thus, they would require difficult-to-instrument rigid internal fixations that limit a rigorous evaluation of the regeneration progress through the analysis of mechanic-structural parameters. METHODS: We investigated the compatibility of flexible fixations with fragile ceramic implants, and if mechanical monitoring techniques are applicable to bone tissue engineering applications. Tissue engineering experiments were performed on 8 ovine metatarsi. A 15 mm bone segment was directly replaced with a hydroxyapatite scaffold and stabilized by an instrumented Ilizarov-type external fixator. Several in vivo monitoring techniques were employed to assess the mechanical and structural progress of the tissue. RESULTS: The applied surgical protocol succeeded in combining external fixators and subject-specific bioceramic scaffolds without causing fatal fractures of the implant due to stress concentrator. The bearing capacity of the treated limb was initially altered, quantifying a 28-56% reduction of the ground reaction force, which gradually normalized during the consolidation phase. A faster recovery was reported in the bearing capacity, stiffening and bone mineral density of the callus. It acquired a predominant mechanical role over the fixator in the distribution of internal forces after one post-surgical month. CONCLUSION: The bioceramic scaffold significantly accelerated in vivo the bone formation compared to other traditional alternatives in the literature (e.g., distraction osteogenesis). In addition, the implemented assessment techniques allowed an accurate quantitative evaluation of the bone regeneration through mechanical and imaging parameters.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Ovinos , Animais , Alicerces Teciduais/química , Engenharia Tecidual/métodos , Regeneração Óssea , Osso e Ossos , Impressão Tridimensional
8.
Int J Technol Assess Health Care ; 39(1): e50, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37403252

RESUMO

OBJECTIVES: Spain incorporated in 2020 changes in its health technology assessment (HTA), pricing, and reimbursement system for medicines including publishing reports, development of networks of experts, or consultation with stakeholders. Despite these changes, it is unclear how deliberative frameworks are applied and the process has been criticized for not being sufficiently transparent. This study analyses the level of implementation of deliberative processes in HTA for medicines in Spain. METHODS: We review the grey literature and summarize the Spanish HTA, pricing, and reimbursement process of medicines. We apply the deliberative processes for HTA checklist, developed to assess the overall context of the deliberative process, and identify the stakeholders involved and type of involvement following the framework for evidence-informed deliberative processes, a framework for benefit package design that aims to optimize the legitimacy of decision making. RESULTS: In the Spanish HTA, pricing, and reimbursement process deliberation takes place in order to exchange viewpoints and reach common ground, mainly during the prioritization, assessment, and appraisal steps. It is closed to the public, not clearly summarized in published documents and limited to the Ministry of Health, the regulatory agency, other Ministries, and experts with mostly clinical and/or pharmaceutical background. The views of stakeholders are only represented through consultation. Communication is the most commonly used form of stakeholder engagement. CONCLUSIONS: Despite improvements in transparency of the Spanish HTA process for evaluating medicines, aspects related to stakeholder involvement and implementation of deliberative frameworks need further attention in order to achieve further legitimacy of the process.


Assuntos
Participação dos Interessados , Avaliação da Tecnologia Biomédica , Espanha
9.
Expert Rev Med Devices ; 20(10): 851-864, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37522639

RESUMO

BACKGROUND: Proper maintenance of electro-medical devices is crucial for the quality of care to patients and the economic performance of healthcare organizations. This research aims to identify the interaction between Ultrasound scanners (US) maintenance variables as a function of maintenance indicators: US in service or decommissioned, excessive number of failures, and failure rate. Knowing those interactions, specific maintenance measures will be developed to improve the reliability of the US. RESEARCH DESIGN AND METHODS: Multifactor Dimensionality Reduction (MDR) method was eployed to analyze data from 222 US and their four-year maintenance history. Models were developed based on the variables with the greatest influence on maintenance indicators, where US were classified according to the associated risk. RESULTS: US with more than one major failure or at least one major component replacement had up to 496.4% more failures than the average. Failure rate increased by up to 188.7% over the average for those US with more than three moderate failures, three replacements, or both. CONCLUSIONS: This study identifies and quantifies the causes of risk to establish a specific maintenance plan for US. It helps to better understand the degradation of US to optimize their operation and maintenance.


Assuntos
Modelos Genéticos , Redução Dimensional com Múltiplos Fatores , Humanos , Redução Dimensional com Múltiplos Fatores/métodos , Reprodutibilidade dos Testes , Ultrassonografia
10.
BMJ Open ; 13(6): e068183, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37380213

RESUMO

OBJECTIVE: To assess differences in acute ischaemic stroke (AIS) in-hospital mortality between referral stroke hospitals and provide evidence on the association of those differences with the overtime adoption of effective reperfusion therapies. DESIGN: Retrospective, longitudinal observational study using administrative data for virtually all hospital admissions from 2003 to 2015. SETTING: Thirty-seven referral stroke hospitals in the Spanish National Health System. PARTICIPANTS: Patients aged 18 years and older with a hospital episode with an admission diagnosis of AIS in any referral stroke hospital (196 099 admissions). MAIN ENDPOINTS: (1) Hospital variation in 30-day in-hospital mortality measured in terms of the intraclass correlation coefficient (ICC); and (2) the difference in mortality between the hospital of treatment and the trend of utilisation of reperfusion therapies (including intravenous fibrinolysis and endovascular mechanical thrombectomy) in terms of median OR (MOR). RESULTS: Adjusted 30-day AIS in-hospital mortality decreased over the study period. Adjusted in-hospital mortality after AIS rates varied from 6.66% to 16.01% between hospitals. Beyond differences in patient characteristics, the relative contribution of the hospital of treatment was higher in the case of patients undergoing reperfusion therapies (ICC=0.031 (95% Bayesian credible interval (BCI)=0.017 to 0.057)) than in the case of those who did not (ICC=0.016 (95% BCI=0.010 to 0.026)). Using the MOR, the difference in risk of death was as high as 46% between the hospital with the highest risk and the hospital with the lowest risk of patients undergoing reperfusion therapy (MOR 1.46 (95% BCI 1.32 to 1.68)); in patients not undergoing any reperfusion therapy, the risk was 31% higher (MOR 1.31 (95% BCI 1.24 to 1.41)). CONCLUSIONS: In the referral stroke hospitals of the Spanish National Health System, the overall adjusted in-hospital mortality decreased between 2003 and 2015. However, between-hospital variations in mortality persisted.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/terapia , Estudos Retrospectivos , Mortalidade Hospitalar , Espanha/epidemiologia , Teorema de Bayes , Isquemia Encefálica/terapia , Hospitais , Encaminhamento e Consulta
11.
Zoonoses Public Health ; 70(5): 445-450, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36915955

RESUMO

Chagas disease, considered a neglected disease, was initially confined to rural localities in endemic areas; however, in recent years through the process of urbanization and migration of infected people, the disease is gaining importance in urban environments. The presence of the vector in urban areas in most cases is due to the passive transport of vectors, but recently, its presence seems to be linked to vector adaptation processes associated with climate change. This paper reports the occurrence of an infected triatomine in the peridomicile of a house in an urban area of Córdoba, Veracruz, Mexico, where the species found is described, the molecular characteristics and resistance to BZN and NFX of the Trypanosoma cruzi isolate obtained, as well as serological data of the dwelling inhabitants. These urban disease scenarios make it possible to generate new scientific knowledge and enable the creation of new control strategies for Chagas disease vectors.


Assuntos
Doença de Chagas , Triatoma , Trypanosoma cruzi , Animais , México/epidemiologia , Insetos Vetores , Doença de Chagas/epidemiologia , Doença de Chagas/veterinária
12.
Appl Microbiol Biotechnol ; 106(17): 5525-5538, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35896838

RESUMO

The rhizosphere context of inulin-accumulating plants, such as Jerusalem artichoke (Helianthus tuberosus), is an ideal starting basis for the discovery of inulolytic enzymes with potential for bio fructose production. We isolated a Glutamicibacter mishrai NJAU-1 strain from this context, showing exo-inulinase activity, releasing fructose from fructans. The growth conditions (pH 9.0; 15 °C) were adjusted, and the production of inulinase by Glutamicibacter mishrai NJAU-1 increased by 90% (0.32 U/mL). Intriguingly, both levan and inulin, but not fructose and sucrose, induced the production of exo-inulinase activity. Two exo-inulinase genes (inu1 and inu2) were cloned and heterologously expressed in Pichia pastoris. While INU2 preferentially hydrolyzed longer inulins, the smallest fructan 1-kestose appeared as the preferred substrate for INU1, also efficiently degrading nystose and sucrose. Active site docking studies with GFn- and Fn-type small inulins (G is glucose, F is fructose, and n is the number of ß (2-1) bound fructose moieties) revealed subtle substrate differences between INU1 and INU2. A possible explanation about substrate specificity and INU's protein structure is then suggested. KEY POINTS: • A Glutamicibacter mishrai strain harbored exo-inulinase activity. • Fructans induced the inulolytic activity in G. mishrai while the inulolytic activity was optimized at pH 9.0 and 15 °C. • Two exo-inulinases with differential substrate specificity were characterized.


Assuntos
Helianthus , Frutanos , Frutose , Glicosídeo Hidrolases , Inulina , Sacarose
13.
Proc Inst Mech Eng H ; 236(9): 1457-1461, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35880879

RESUMO

Callus tissue exhibits a viscoelastic behavior that has a strong influence on the distribution of stresses and their evolution with time and, thus, it can affect tissue differentiation during distraction procedures. For this reason, a deep knowledge of that viscoelastic behavior can be very useful to improve current protocols of bone distraction and bone transport. Monitoring stress relaxation of the callus during distraction osteogenesis allows characterizing its viscoelastic behavior. Different procedures have been used in the literature to fit the response of a given viscoelastic model to the force relaxation curve. However, these procedures do not ensure the uniqueness of that fit, which is of the utmost importance for statistical purposes. This work uses a fitting procedure already validated for other tissues that ensures that uniqueness. Very importantly too, the procedure presented here allows obtaining more information from the stress relaxation tests, distinguishing relaxation in different time scales, which provides a deeper insight into the viscoelastic behavior and its evolution over time. As it was observed in the results, relaxation is faster at the first days after osteotomy and becomes slower and more gradual with time. This fact can be directly linked to the temporal evolution of the callus composition (water, organic phase, and mineral content) and also to the progression of tissue differentiation, with a prevalence of hard tissues as time passes.


Assuntos
Calo Ósseo , Osteogênese por Distração , Fenômenos Mecânicos , Osteogênese por Distração/métodos , Osteotomia
14.
Ann Biomed Eng ; 50(12): 1798-1809, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35732853

RESUMO

Collagen is a ubiquitous protein present in regenerating bone tissues that experiences multiple biological phenomena during distraction osteogenesis until the deposition of phosphate crystals. This work combines fluorescence techniques and mathematical modeling to shed light on the mechano-structural processes behind the maturation and accommodation-to-mineralization of the callus tissue. Ovine metatarsal bone calluses were analyzed through confocal images at different stages of the early distraction osteogenesis process, quantifying the fiber orientation distribution and mean intensity as fiber density measure. Likewise, a mathematical model based on the experimental data was defined to micromechanically characterize the apparent stiffening of the tissue within the distracted callus. A reorganization of the fibers around the distraction axis and increased fiber density were found as the bone fragments were gradually separated. Given the degree of significance between the mathematical model and previous in vivo data, reorganization, densification, and bundle maturation phenomena seem to explain the apparent mechanical maturation observed in the tissue theoretically.


Assuntos
Osteogênese por Distração , Osteogênese , Ovinos , Animais , Calo Ósseo/diagnóstico por imagem , Osteogênese por Distração/métodos , Diagnóstico por Imagem , Modelos Teóricos , Regeneração Óssea
15.
J Exp Bot ; 73(5): 1602-1622, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-34750605

RESUMO

Fructan metabolism in bacteria and plants relies on fructosyltransferases and fructanases. Plant fructanases (fructan exohydrolase, FEH) only hydrolyse terminal fructose residues. Levan (ß-2,6 linkages) is the most abundant fructan type in bacteria. Dicot fructan accumulators, such as chicory (Cichorium intybus), accumulate inulin (ß-2,1 linkages), harbouring several 1-FEH isoforms for their degradation. Here, a novel chicory fructanase with high affinity for levan was characterized, providing evidence that such enzymes widely occur in higher plants. It is adapted to common microbial fructan profiles, but has low affinity towards chicory inulin, in line with a function in trimming of microbial fructans in the extracellular environment. Docking experiments indicate the importance of an N-glycosylation site close to the active site for substrate specificity. Optimal pH and temperature for levan hydrolysis are 5.0 and 43.7 °C, respectively. Docking experiments suggested multiple substrate binding sites and levan-mediated enzyme dimerization, explaining the observed positive cooperativity. Alignments show a single amino acid shift in the position of a conserved DXX(R/K) couple, typical for sucrose binding in cell wall invertases. A possible involvement of plant fructanases in levan trimming is discussed, in line with the emerging 'fructan detour' concepts, suggesting that levan oligosaccharides act as signalling entities during plant-microbial interactions.


Assuntos
Cichorium intybus , Sequência de Aminoácidos , Cichorium intybus/metabolismo , Frutanos/metabolismo , Glicosídeo Hidrolases/metabolismo , beta-Frutofuranosidase/metabolismo
16.
Sci Rep ; 11(1): 12306, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-34112903

RESUMO

Chagas disease remains a major neglected disease in Colombia. We aimed to characterize Trypanosoma cruzi transmission networks in the Sierra Nevada de Santa Marta (SNSM) region, to shed light on disease ecology and help optimize control strategies. Triatomines were collected in rural communities and analyzed for blood feeding sources, parasite diversity and gut microbiota composition through a metagenomic and deep sequencing approach. Triatoma dimidiata predominated, followed by Rhodnius prolixus, Triatoma maculata, Rhodnius pallescens, Panstrongylus geniculatus and Eratyrus cuspidatus. Twenty-two species were identified as blood sources, resulting in an integrated transmission network with extensive connectivity among sylvatic and domestic host species. Only TcI parasites were detected, predominantly from TcIb but TcIa was also reported. The close relatedness of T. cruzi strains further supported the lack of separate transmission cycles according to habitats or triatomine species. Triatomine microbiota varied according to species, developmental stage and T. cruzi infection. Bacterial families correlated with the presence/absence of T. cruzi were identified. In conclusion, we identified a domestic transmission cycle encompassing multiple vector species and tightly connected with sylvatic hosts in the SNSM region, rather than an isolated domestic transmission cycle. Therefore, integrated interventions targeting all vector species and their contact with humans should be considered.


Assuntos
Microbioma Gastrointestinal/genética , Variação Genética , Triatoma/genética , Triatominae/genética , Animais , Doença de Chagas/genética , Doença de Chagas/parasitologia , Doença de Chagas/patologia , Genótipo , Humanos , Insetos Vetores/genética , Grupos Populacionais , Rhodnius/patogenicidade , Triatoma/classificação , Triatominae/parasitologia , Trypanosoma cruzi/genética , Trypanosoma cruzi/patogenicidade
17.
J Mech Behav Biomed Mater ; 121: 104613, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34126507

RESUMO

Tissue engineering has recently gained popularity as an alternative to autografts to stimulate bone tissue regeneration through structures called scaffolds. Most of the in vivo experiments on long-bony defects use internally-stabilized generic scaffolds. Despite the wide variety of computational methods, a standardized protocol is required to optimize ceramic scaffolds for load-bearing bony defects stabilized with flexible fixations. An optimization problem was defined for applications to sheep metatarsus defects. It covers biological parameters (porosity, pore size, and the specific surface area) and mechanical constraints based on in vivo and in vitro results reported in the literature. The optimized parameters (59.30% of porosity, 5768.91 m-1 of specific surface area, and 360.80 µm of pore size) and the compressive strength of the selected structure were validated in vitro by means of tomographic images and compression tests of six 3D-printed samples. Divergences between the design and measured values of the optimized parameters, mainly due to manufacturing defects, are consistent with the previous studies. Using the mixed experimental-mathematical scaffold-design procedure described, they could be implanted in vivo with instrumented external fixators, therefore facilitating biomechanical monitoring of the regeneration process.


Assuntos
Impressão Tridimensional , Alicerces Teciduais , Animais , Regeneração Óssea , Cerâmica , Humanos , Porosidade , Ovinos , Engenharia Tecidual , Suporte de Carga
18.
Int J Infect Dis ; 108: 320-329, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34098097

RESUMO

OBJECTIVE: In Belize, the main vector for Trypanosoma cruzi, the agent of Chagas disease, is Triatoma dimidiata, but transmission cycles and the risk for human infection are unclear. Therefore, the aim of this study was to identify T. dimidiata blood feeding sources and its parasite and microbial diversity, in order to reconstruct T. cruzi parasite transmission ecology in southern Belize. METHODS: A metabarcoding approach based on deep sequencing of markers was used for bug taxonomy, blood meal sources, T. cruzi genotypes, and microbiota composition. Bugs were collected in 13 villages of Toledo district. RESULTS: Bugs fed on at least 13 species, from domestic hosts such as humans, dogs, cows, and pigs, to synanthropic species such as mice, rats, and opossums, and sylvatic species such as deer, peccary, and kinkajou, in agreement with an opportunistic feeding behavior. Nonetheless, most feeding focused on a few species, including humans. Infection with T. cruzi was detected in 24 of 39 bugs (62%), and the analysis of 242 T. cruzi mini-exon sequences (average 10 ± 5 haplotypes per bug) indicated the presence of TcI and TcIV parasite discrete typing units (DTUs). However, for both DTUs, sequences from Belize mostly clustered apart from sequences from North and South America, suggesting the local differentiation of parasites. T. dimidiata also harbored a diverse bacterial microbiota, with ontogenic changes suggesting microbiota maturation during nymphal development. CONCLUSIONS: Together, these results indicate a significant risk for T. cruzi infection in humans. They also highlight the need to better characterize the diversity of T. cruzi strains in the region and its impact on disease epidemiology.


Assuntos
Doença de Chagas , Cervos , Parasitos , Triatoma , Trypanosoma cruzi , Animais , Belize , Bovinos , Doença de Chagas/epidemiologia , Cães , Feminino , Humanos , Insetos Vetores , Camundongos , Ratos , Suínos , Trypanosoma cruzi/genética
19.
Microorganisms ; 9(4)2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33918392

RESUMO

Fructans are fructose-based (poly)saccharides with inulin and levan being the best-known ones. Thanks to their health-related benefits, inulin-type fructans have been under the focus of scientific and industrial communities, though mostly represented by plant-based inulins, and rarely by microbial ones. Recently, it was discovered that some extremely halophilic Archaea are also able to synthesize fructans. Here, we describe the first in-depth functional and molecular characterization of an Archaeal inulosucrase from Halomicrobium sp. IBSBa (HmcIsc). The HmcIsc enzyme was recombinantly expressed and purified in Escherichia coli and shown to synthesize inulin as proven by nuclear magnetic resonance (NMR) analysis. In accordance with the halophilic lifestyle of its native host, the enzyme showed maximum activity at very high NaCl concentrations (3.5 M), with specific adaptations for that purpose. Phylogenetic analyses suggested that Archaeal inulosucrases have been acquired from halophilic bacilli through horizontal gene transfer, with a HX(H/F)T motif evolving further into a HXHT motif, together with a unique D residue creating the onset of a specific alternative acceptor binding groove. This work uncovers a novel area in fructan research, highlighting unexplored aspects of life in hypersaline habitats, and raising questions about the general physiological relevance of inulosucrases and their products in nature.

20.
Acta Parasitol ; 66(3): 1068-1073, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33616814

RESUMO

PURPOSE: Leishmaniasis is an infectious disease transmitted by insects that proliferate mainly in impoverished environments of tropical climates. In the absence of an effective vaccine, pharmacological treatment is the main tool to combat this disease. The objective of this work was to analyze the anti-leishmanial activity of 2-chloro-N-[4-(4-chlorophenyl)-2-thiazolyl] acetamide (AT) in promastigotes of Leishmania mexicana. METHODS: The biological activity of the compound was evaluated using a sulphorhodamine B cytotoxicity test and the integrity of the erythrocytes was evaluated by a lysis test. The anti-trypanosomatid activity was evaluated in vitro, a cell death assay was performed by flow cytometry (IP/Annexin V stain) and a parasite growth recovery assay was performed. RESULTS: The AT showed a CC50 value of 0.031 µM for HeLa cells after 24 h of exposure, which did not induce erythrocyte lysis. On the other hand, the AT showed an IC50 value of 0.086 µM for L. mexicana (promastigote form) after 24 h of interaction. The compound was capable of inducing apoptosis in the parasites and did not allow recovery after 24 h of exposure. CONCLUSION: This study provides valuable information with the objective of developing new drugs for the treatment of this disease, although more research on this molecule is needed to improve its biological activity.


Assuntos
Antiprotozoários , Leishmania mexicana , Leishmaniose , Acetamidas/uso terapêutico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Apoptose , Células HeLa , Humanos
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