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1.
Hum Mol Genet ; 28(4): 525-538, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30304524

RESUMO

Aminoacyl-tRNA synthetases (ARSs) are critical for protein translation. Pathogenic variants of ARSs have been previously associated with peripheral neuropathy and multisystem disease in heterozygotes and homozygotes, respectively. We report seven related children homozygous for a novel mutation in tyrosyl-tRNA synthetase (YARS, c.499C > A, p.Pro167Thr) identified by whole exome sequencing. This variant lies within a highly conserved interface required for protein homodimerization, an essential step in YARS catalytic function. Affected children expressed a more severe phenotype than previously reported, including poor growth, developmental delay, brain dysmyelination, sensorineural hearing loss, nystagmus, progressive cholestatic liver disease, pancreatic insufficiency, hypoglycemia, anemia, intermittent proteinuria, recurrent bloodstream infections and chronic pulmonary disease. Related adults heterozygous for YARS p.Pro167Thr showed no evidence of peripheral neuropathy on electromyography, in contrast to previous reports for other YARS variants. Analysis of YARS p.Pro167Thr in yeast complementation assays revealed a loss-of-function, hypomorphic allele that significantly impaired growth. Recombinant YARS p.Pro167Thr demonstrated normal subcellular localization, but greatly diminished ability to homodimerize in human embryonic kidney cells. This work adds to a rapidly growing body of research emphasizing the importance of ARSs in multisystem disease and significantly expands the allelic and clinical heterogeneity of YARS-associated human disease. A deeper understanding of the role of YARS in human disease may inspire innovative therapies and improve care of affected patients.


Assuntos
Doenças Genéticas Inatas/genética , Predisposição Genética para Doença , Mutação com Perda de Função/genética , Tirosina-tRNA Ligase/genética , Adulto , Domínio Catalítico/genética , Pré-Escolar , Feminino , Doenças Genéticas Inatas/fisiopatologia , Perda Auditiva Neurossensorial/diagnóstico por imagem , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/fisiopatologia , Heterozigoto , Homozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Linhagem , Fenótipo , Índice de Gravidade de Doença , Sequenciamento do Exoma , Leveduras/genética
2.
J Insect Sci ; 20(4)2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32770249

RESUMO

Insect predators are seldom considered during toxicological trophic assessments for insecticide product development. As a result, the ecological impact of novel insecticides on predators is not well understood, especially via the food chain, i.e., when their prey is exposed to insecticides. Neonicotinoids are systemic insecticides widely used in agriculture to control herbivorous insects, but their effects on predatory insects via the food chain have not been well characterized. In this study, we documented the time-course effects of the neonicotinoid thiamethoxam on the survival of two predators, the insidiosus flower bug Orius insidiosus (Say) and the convergent lady beetle Hippodamia convergens Guérin-Méneville, when preying upon the aphids Aphis glycines Matsumura (Hemiptera: Aphididae), Aphis gossypii Glover (Hemiptera: Aphididae), and Myzus persicae (Sulzer) (Hemiptera: Aphididae). Aphids were exposed to thiamethoxam-treated or untreated plants every week over the course of 5 wk. After transferring aphids to Petri dishes, predators were allowed to feed on aphids. We found that the survival of the insidiosus flower bug, but not the convergent lady beetle, was reduced after consuming aphids reared on thiamethoxam-treated plants compared to untreated plants. Survival reduction of the insidiosus flower bug was observed only during the first weeks after thiamethoxam application; no reduction occurred 28 d after treatment or beyond. These results demonstrate that a systemic application of thiamethoxam could be compatible with convergent lady beetles and insidiosus flower bugs, if the time of predator release does not coincide with thiamethoxam activity. These findings are critical for the development of future pest control programs that integrate biological and chemical control.


Assuntos
Besouros/efeitos dos fármacos , Heterópteros/efeitos dos fármacos , Inseticidas/efeitos adversos , Tiametoxam/efeitos adversos , Animais , Dieta , Feminino , Cadeia Alimentar , Longevidade/efeitos dos fármacos , Masculino , Comportamento Predatório , Especificidade da Espécie
3.
J Pharm Pharm Sci ; 22(1): 313-331, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31329535

RESUMO

The electrospinning technique is a useful and versatile approach for conversion of polymeric solutions into continuous fibers, ranging from a few micrometers (10-100 µm) to the scale of nanometers (10- 100 nm) in diameters. This technique can be used in a vast number of polymers, in some cases after modifying them to the required properties. The high surface-to-volume ratio of the fibers can improve some processes like cell binding and proliferation, drug loading, and mass transfer processes. One of the most important and studied areas of electrospinning is in the drug delivery field, for the controlled release of active substances ranging from antibiotics and anticancer agents, to macromolecules such as proteins and DNA. The advantage of this method is that a wide variety of low solubility drugs can be loaded into the fibers to improve their bioavailability or to attain controlled release. This review presents an overview of the reported drugs loaded into electrospun polymeric nanofibers to be used as drug delivery systems. These drugs are classified by their applications in pharmacy.


Assuntos
Antibacterianos/química , Antineoplásicos/química , Sistemas de Liberação de Medicamentos , Nanofibras/química , Polímeros/química , Portadores de Fármacos/química , Eletricidade , Humanos , Tamanho da Partícula , Propriedades de Superfície
4.
Water Environ Res ; 90(10): 1073-1090, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30126479

RESUMO

This section presents a review of the scientific literature published in 2017 on topics relating to sustainable bioenergy from biofuel residues and waste. This review is divided into the following sections: Feedstocks, Bioethanol, Biodiesel, Biohydrogen, Hydrogen, Biofuel Residues, Microalgae, Lignocelluloses and other topics.


Assuntos
Biocombustíveis , Desenvolvimento Sustentável , Resíduos , Biomassa
5.
Plant Biotechnol J ; 15(9): 1214-1224, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28207991

RESUMO

Microalga-based biomanufacturing of recombinant proteins is attracting growing attention due to its advantages in safety, metabolic diversity, scalability and sustainability. Secretion of recombinant proteins can accelerate the use of microalgal platforms by allowing post-translational modifications and easy recovery of products from the culture media. However, currently, the yields of secreted recombinant proteins are low, which hampers the commercial application of this strategy. This study aimed at expanding the genetic tools for enhancing secretion of recombinant proteins in Chlamydomonas reinhardtii, a widely used green microalga as a model organism and a potential industrial biotechnology platform. We demonstrated that the putative signal sequence from C. reinhardtii gametolysin can assist the secretion of the yellow fluorescent protein Venus into the culture media. To increase the secretion yields, Venus was C-terminally fused with synthetic glycomodules comprised of tandem serine (Ser) and proline (Pro) repeats of 10 and 20 units [hereafter (SP)n , wherein n = 10 or 20]. The yields of the (SP)n -fused Venus were higher than Venus without the glycomodule by up to 12-fold, with the maximum yield of 15 mg/L. Moreover, the presence of the glycomodules conferred an enhanced proteolytic protein stability. The Venus-(SP)n proteins were shown to be glycosylated, and a treatment of the cells with brefeldin A led to a suggestion that glycosylation of the (SP)n glycomodules starts in the endoplasmic reticulum (ER). Taken together, the results demonstrate the utility of the gametolysin signal sequence and (SP)n glycomodule to promote a more efficient biomanufacturing of microalgae-based recombinant proteins.


Assuntos
Chlamydomonas reinhardtii/metabolismo , Metaloproteases/metabolismo , Processamento de Proteína Pós-Traducional , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes de Fusão/metabolismo , Biotecnologia , Chlamydomonas reinhardtii/genética , Chlamydomonas reinhardtii/crescimento & desenvolvimento , Meios de Cultura , Genes Reporter , Glicoproteínas/genética , Glicoproteínas/metabolismo , Glicosilação , Metaloproteases/genética , Plantas Geneticamente Modificadas , Transporte Proteico , Proteínas Recombinantes de Fusão/genética
6.
Microb Cell Fact ; 15(1): 186, 2016 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-27825349

RESUMO

BACKGROUND: Cyanobacteria are photosynthetic bacteria that thrive in diverse ecosystems and play major roles in the global carbon cycle. The abilities of cyanobacteria to fix atmospheric CO2 and to allocate the fixed carbons to chemicals and biofuels have attracted growing attentions as sustainable microbial cell factories. Better understanding of the activities of enzymes involved in the central carbon metabolism would lead to increasing product yields. Currently cell-free lysates are the most widely used method for determination of intracellular enzyme activities. However, due to thick cell walls, lysis of cyanobacterial cells is inefficient and often laborious. In some cases radioisotope-labeled substrates can be fed directly to intact cells; however, label-free assays are often favored due to safety and practical reasons. RESULTS: Here we show an easy and highly efficient method for permeabilization of the cyanobacteria Synechococcus sp. PCC 7002 and Synechocystis sp. PCC 6803, and determination of two intracellular enzymes, ribulose-1,5-bisphosphate carboxylase/decarboxylase (Rubisco) and glucose-6-phosphate dehydrogenase (G6PDH), that play pivotal roles in the central carbon metabolism in cyanobacteria. Incubation of the cyanobacterial cells in the commercially available B-PER reagent for 10 min permeabilized the cells, as confirmed by the SYTOX Green staining. There was no significant change in the cell shape and no major loss of intracellular proteins was observed during the treatment. When used directly in the assays, the permeabilized cells exhibited the enzyme activities that are comparable or even higher than those detected for cell-free lysates. Moreover, the permeabilized cells could be stored at -20 °C without losing the enzyme activities. The permeabilization process and subsequent activity assays were successfully adapted to the 96-well plate system. CONCLUSIONS: An easy, efficient and scalable permeabilization protocol was established for cyanobacteria. The permeabilized cells can be directly applied for measurement of G6PDH and Rubisco activities without using radioisotopes and the protocol may be readily adapted to studies of other cyanobacterial species and other intracellular enzymes. The permeabilization and enzyme assays can be performed in 96-well plates in a high-throughput manner.


Assuntos
Proteínas de Bactérias/metabolismo , Glucosefosfato Desidrogenase/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Synechococcus/enzimologia , Synechocystis/enzimologia , Permeabilidade da Membrana Celular , Permeabilidade
7.
J Exp Bot ; 66(22): 6975-90, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26400987

RESUMO

Microalgae are a diverse group of single-cell photosynthetic organisms that include cyanobacteria and a wide range of eukaryotic algae. A number of microalgae contain high-value compounds such as oils, colorants, and polysaccharides, which are used by the food additive, oil, and cosmetic industries, among others. They offer the potential for rapid growth under photoautotrophic conditions, and they can grow in a wide range of habitats. More recently, the development of genetic tools means that a number of species can be transformed and hence used as cell factories for the production of high-value chemicals or recombinant proteins. In this article, we review exploitation use of microalgae with a special emphasis on genetic engineering approaches to develop cell factories, and the use of synthetic ecology approaches to maximize productivity. We discuss the success stories in these areas, the hurdles that need to be overcome, and the potential for expanding the industry in general.


Assuntos
Biotecnologia , Microalgas , Engenharia Genética , Microbiologia Industrial , Microalgas/genética
8.
Interv Neuroradiol ; 29(2): 189-195, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35234070

RESUMO

INTRODUCTION: Acute respiratory distress syndrome (ARDS) is a known predictor of poor outcomes in critically ill patients. We sought to examine the role ARDS plays in outcomes in subarachnoid hemorrhage (SAH) patients. Prior studies investigating the incidence of ARDS in SAH patients did not control for SAH severity. Hence, we sought to determine the incidence ARDS in patients diagnosed with aneurysmal SAH and investigate the predisposing risk factors and impact upon outcomes. METHODS: A retrospective cohort study was conducted using the National Inpatient Sample (NIS) database for the years 2008 to 2014. Multivariate stepwise regression analysis was performed to identify the risk factors and outcome associated with developing ARDS in the setting of SAH. RESULTS: We identified 170,869 patients with non-traumatic subarachnoid hemorrhage, of whom 6962 were diagnosed with ARDS and of those 4829 required mechanical ventilation. ARDS more frequently developed in high grade SAH patients (1.97 ± 0.05 vs. 1.15 ± 0.01; p < 0.0001). Neurologic predictors of ARDS included cerebral edema (OR 1.892, CI 1.180-3.034, p = 0.0035) and medical predictors included cardiac arrest (OR 4.642, CI 2.273-9.482, p < 0.0001) and cardiogenic shock (OR 2.984, CI 1.157-7.696, p = 0.0239). ARDS was associated with significantly worse outcomes (15.5% vs. 52.9% discharged home, 63.0% vs. 40.8% discharged to rehabilitation facility and 21.5% vs. 6.3% in-hospital mortality). CONCLUSION: Patients with SAH who developed ARDS were less likely to be discharged home, more likely to need rehabilitation and had a significantly higher risk of mortality. The identification of risk factors contributing to ARDS is helpful for improving outcomes and resource utilization.


Assuntos
Síndrome do Desconforto Respiratório , Hemorragia Subaracnóidea , Humanos , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/cirurgia , Estudos Retrospectivos , Incidência , Pacientes Internados , Fatores de Risco , Síndrome do Desconforto Respiratório/complicações
9.
Interv Neuroradiol ; 29(4): 363-370, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35354315

RESUMO

BACKGROUND: Heparin induced thrombocytopenia Type II (HIT-II) is a dangerous thromboembolic complication of heparin therapy. The current literature on incidence and outcomes of HIT-II in aneurysmal subarachnoid hemorrhage (aSAH) patients remains sparse. OBJECTIVE: We report our institution's incidence and outcomes of HIT-II in aSAH patients. METHODS: We performed a retrospective cohort study at an academic medical center between June 2014 and July 2018. All patients had aSAH confirmed by digital subtraction angiography. Diagnosis of HIT-II was determined by positive results on both heparin PF4-platelet antibody ELISA (anti-PF4) and serotonin release assay (SRA). RESULTS: 204 patients met inclusion criteria. Seven patients (7/204, 3.5%) underwent laboratory testing, three of whom met clinical criteria. HIT-II incidence was confirmed in two of these seven patients (2/204, 0.98%), who had high BMI and T4 scores. CONCLUSION: Our institution's report of HIT-II incidence in aSAH patients is lower than previously reported in this population and more closely parallels HIT-II incidence in the general and surgical ICU setting. Widely-accepted American College of Chest Physicians (ACCP) clinical diagnostic criteria in conjunction with anti-PF4 and SRA testing is the gold standard of clinical diagnosis of HIT-II in aSAH patients.


Assuntos
Hemorragia Subaracnóidea , Trombocitopenia , Trombose , Humanos , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/tratamento farmacológico , Estudos Retrospectivos , Trombocitopenia/induzido quimicamente , Heparina/efeitos adversos , Anticoagulantes/efeitos adversos
10.
Neurocirugia (Astur) ; 23(4): 136-44, 2012 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-22717230

RESUMO

INTRODUCTION AND OBJECTIVES: Pial arteriovenous fistulas are infrequent vascular malformations. They are generally congenital and their natural history is ominous. The objective of this work is to describe our experience in their endovascular management and to review the existing literature. PATIENTS AND METHODS: This is a retrospective and descriptive study of patients treated by endovascular approach during 3 years at 3 Latin-American hospitals. RESULTS: The study included 6 patients with a mean age of 22 years. One case was caused by cranial trauma. In total, 50% suffered intracranial haemorrhage and 66% developed symptoms attributable to volume effect or retrograde blood flow. Intracranial varices were identified by CT and MRI scans in 83% of cases. Digital subtraction angiography showed arteriovenous fistulas from anterior circulation in 67% of cases and deep venous drainage in 50%. One endovascular procedure was performed in 5 cases (83%), while 2 procedures were required in one case. A single embolic agent was used to occlude fistulas in 67% of cases; whilst 33% required a combination. Coils were used in 4 cases (67%) and onyx was injected in another 4 (67%). One case required stent and balloon deployment. The fistulas were uneventfully occluded in all cases. The follow-up period was one year in 5 cases and 6 months in one case. All patients remained symptom-free. CONCLUSIONS: Endovascular management can be considered as the treatment of choice. It consists in the embolisation of arterial pedicles with one or more embolic agents and should be performed as close as possible to the drainage vein, avoiding migration of the embolic agent towards the venous side.


Assuntos
Polivinil , Resultado do Tratamento , Fístula Arteriovenosa , Embolização Terapêutica , Humanos , Estudos Retrospectivos
11.
Front Neurol ; 12: 615593, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33613432

RESUMO

Glioblastoma multiforme (GBM), the most common malignant brain tumor, universally carries a poor prognosis. Despite aggressive multimodality treatment, the median survival is ~18-20 months, depending on molecular subgroups. A long history of observations suggests antitumor effects of bacterial infections against malignant tumors. The present review summarizes and critically analyzes the clinical data providing evidence for or against the survival benefit of post-operative bacterial infections in GBM patients. Furthermore, we explore the probable underlying mechanism(s) from basic science studies on the topic. There are plausible explanations from immunobiology for the mechanism of the "favorable effect" of bacterial infections in GBM patients. However, available clinical literature does not provide a definitive association between postoperative bacterial infection and prolonged survival in GBM patients. The presently available, single-/multi-center and national database retrospective case-control studies on the topic provide conflicting results. A prospective randomized study on the subject is clearly not possible. Immunobiology literature supports development of genetically modified bacteria as part of multimodal regimen against GBM.

12.
Mol Neurobiol ; 58(11): 5494-5516, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34341881

RESUMO

Spinal cord injury (SCI) is a devastating condition that affects approximately 294,000 people in the USA and several millions worldwide. The corticospinal motor circuitry plays a major role in controlling skilled movements and in planning and coordinating movements in mammals and can be damaged by SCI. While axonal regeneration of injured fibers over long distances is scarce in the adult CNS, substantial spontaneous neural reorganization and plasticity in the spared corticospinal motor circuitry has been shown in experimental SCI models, associated with functional recovery. Beneficially harnessing this neuroplasticity of the corticospinal motor circuitry represents a highly promising therapeutic approach for improving locomotor outcomes after SCI. Several different strategies have been used to date for this purpose including neuromodulation (spinal cord/brain stimulation strategies and brain-machine interfaces), rehabilitative training (targeting activity-dependent plasticity), stem cells and biological scaffolds, neuroregenerative/neuroprotective pharmacotherapies, and light-based therapies like photodynamic therapy (PDT) and photobiomodulation (PMBT). This review provides an overview of the spontaneous reorganization and neuroplasticity in the corticospinal motor circuitry after SCI and summarizes the various therapeutic approaches used to beneficially harness this neuroplasticity for functional recovery after SCI in preclinical animal model and clinical human patients' studies.


Assuntos
Plasticidade Neuronal , Tratos Piramidais/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Animais , Interfaces Cérebro-Computador , Terapia Combinada , Terapia por Estimulação Elétrica , Humanos , Locomoção/fisiologia , Terapia com Luz de Baixa Intensidade , Córtex Motor/fisiopatologia , Regeneração Nervosa , Crescimento Neuronal , Fármacos Neuroprotetores/uso terapêutico , Fotoquimioterapia , Qualidade de Vida , Recuperação de Função Fisiológica , Riluzol/uso terapêutico , Medula Espinal/fisiopatologia , Doenças da Medula Espinal/reabilitação , Traumatismos da Medula Espinal/terapia , Transplante de Células-Tronco , Estimulação Transcraniana por Corrente Contínua , Estimulação Elétrica Nervosa Transcutânea
13.
World Neurosurg ; 148: 141-162, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33482414

RESUMO

OBJECTIVE: The present systematic review and meta-analysis analyzes the available clinical literature on post-intracerebral hemorrhage (ICH) cognitive impairment. METHODS: We conducted a systematic review with meta-analysis following PRISMA guidelines. A search of bibliographic databases up to July 31, 2020 yielded 2155 studies. Twenty articles were included in our final qualitative systematic review and 18 articles in quantitative meta-analysis. RESULTS: Based on analysis of data from 18 studies (3270 patients), we found prevalence of post-ICH cognitive impairment to be 46% (confidence interval, 35.9-55.9), with a follow-up duration ranging from 8 days to 4 years. The estimated pooled prevalence of cognitive decline decreased over longitudinal follow-up, from 55% (range, 37.7%-71.15%) within 6 months of ICH to 35% (range, 27%-42.7%) with >6 months to 4 years follow-up after ICH. The modalities used to evaluate cognitive performance after ICH in studies varied widely, ranging from global cognitive measures to domain-specific testing. The cognitive domain most commonly affected included nonverbal IQ, information processing speed, executive function, memory, language, and visuoconstructive abilities. Prognostic factors for poor cognitive performance included severity of cortical atrophy, age, lobar ICH location, and higher number of hemorrhages at baseline. CONCLUSIONS: The prevalence of post-ICH cognitive impairment is high. Despite the heterogeneity among studies, the present study identified cognitive domains most commonly affected and predictors of cognitive impairment after ICH. In future, prospective cohort studies with larger sample sizes and standardized cognitive domains testing could more accurately determine prevalence and prognostic factors of post-ICH cognitive decline.


Assuntos
Disfunção Cognitiva/etiologia , Hemorragias Intracranianas/complicações , Angiopatia Amiloide Cerebral , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Humanos , Hemorragias Intracranianas/epidemiologia , Hemorragias Intracranianas/psicologia , Testes Neuropsicológicos , Prevalência , Prognóstico
14.
Water Environ Res ; 92(10): 1433-1439, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32574406

RESUMO

This article is a review of the scientific literature published in 2019 on topics relating to bioenergy from biofuel residues and waste. This literature review is divided into the following sections: Feedstocks, Biodiesel, Bioethanol, Hydrogen, Biohydrogen, Biofuel Residues, Microalgae, and Lignocelluloses.


Assuntos
Biocombustíveis , Microalgas
15.
Water Environ Res ; 92(10): 1418-1424, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32574412

RESUMO

This section presents a review of the scientific literature published in 2019 on topics relating to distributed treatment systems. This review is divided into the following sections: constituent removal, treatment technologies, planning and treatment management, and other topics. PRACTITIONER POINTS: Highlights changes and innovation in removal techniques and technologies in water treatment. Reviews management systems of distributed treatment systems. Discusses point-of-use treatment systems.


Assuntos
Eliminação de Resíduos Líquidos , Purificação da Água
16.
Water Environ Res ; 91(10): 1205-1209, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31517427

RESUMO

This section presents a review of the scientific literature published in 2018 on topics relating to distributed treatment systems. This review is divided into the following sections: constituent removal, treatment technologies, planning and treatment management, and other topics.


Assuntos
Reatores Biológicos , Eliminação de Resíduos Líquidos
17.
Water Environ Res ; 91(10): 1199-1204, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31433529

RESUMO

This section presents a review of the scientific literature published in 2018 on topics relating to sustainable bioenergy from biofuel residues and waste. This review is divided into the following sections: Feedstocks, Bioethanol, Biodiesel, Biohydrogen, Hydrogen, Biofuel Residues, Microalgae, and Lignocelluloses.


Assuntos
Biocombustíveis , Microalgas , Hidrogênio
18.
Artigo em Inglês | MEDLINE | ID: mdl-30873405

RESUMO

Microalgae offer a promising biological platform for sustainable biomanufacturing of a wide range of chemicals, pharmaceuticals, and fuels. The model microalga Chlamydomonas reinhardtii is thus far the most versatile algal chassis for bioengineering and can grow using atmospheric CO2 and organic carbons (e.g., acetate and pure cellulose). Ability to utilize renewable feedstock like lignocellulosic biomass as a carbon source could significantly accelerate microalgae-based productions, but this is yet to be demonstrated. We observed that C. reinhardtii was not able to heterotrophically grow using wheat straw, a common type of lignocellulosic biomass, likely due to the recalcitrant nature of the biomass. When the biomass was pretreated with alkaline, C. reinhardtii was able to grow using acetate that was released from the biomass. To establish an eco-friendly and self-sustained growth system, we engineered C. reinhardtii to secrete a fungal acetylxylan esterase (AXE) for hydrolysis of acetylesters in the lignocellulosic biomass. Two transgenic strains (CrAXE03 and CrAXE23) secreting an active AXE into culture media were isolated. Incubation of CrAXE03 with wheat straw resulted in an eight-fold increase in the algal cell counts with a concomitant decrease of biomass acetylester contents by 96%. The transgenic lines showed minor growth defects compared to the parental strain, indicating that secretion of the AXE protein imposes limited metabolic burden. The results presented here would open new opportunities for applying low-cost renewable feedstock, available in large amounts as agricultural and manufacturing by-products, for microalgal cultivation. Furthermore, acetylesters and acetate released from them, are well-known inhibitors in lignocellulosic biofuel productions; thus, direct application of the bioengineered microalga could be exploited for improving renewable biofuel productions.

19.
J Econ Entomol ; 112(2): 712-719, 2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30715412

RESUMO

Thiamethoxam, an insecticide used in soybean seed treatments, effectively suppresses soybean aphids (Aphis glycines) Matsumura (Hemiptera: Aphididae) for a short time after planting. However, exactly when and how quickly soybean aphid populations could increase is unknown. Likewise, we lack data on virulent soybean aphid biotypes (that can overcome soybean resistance) when fed on seed-treated soybean. Determining the survival of soybean aphids over time on insecticidal seed-treated soybean is critical for improving soybean aphid management and may provide insights to manage aphid virulence to aphid resistant-soybean. In greenhouse and field experiments, aphid-susceptible soybean plants (with and without an insecticidal seed treatment) were infested at 7, 14, 21, 28, 35, and 42 days after planting (DAP). We compared aphid survival among biotypes 1 (avirulent) and 4 (virulent) and insecticide treatment 72 h after infestation. We also measured thiamethoxam concentrations in plant tissue using liquid chromatography-tandem mass spectrometry. As expected, soybean aphid survival was significantly lower on seed-treated soybean up to 35 DAP for both biotypes, which correlates with the decrease of thiamethoxam in the plant over time. Moreover, we found no significant difference between avirulent and virulent biotype survivorship on insecticidal seed-treated soybean plants, although we did find significantly greater survival for the virulent biotype compared with the avirulent biotype on untreated soybean in the field. In conclusion, our study further characterized the relative short duration of seed treatment effectiveness on soybean aphid and showed that survivorship of virulent aphids on seed-treated soybean is similar to avirulent aphids.


Assuntos
Afídeos , Inseticidas , Animais , Sementes , Glycine max , Sobrevivência
20.
Int J Nanomedicine ; 14: 5271-5285, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409989

RESUMO

Electrospun nanofibers have been widely studied for many medical applications. They can be designed with specific features, including mucoadhesive properties. This review summarizes the polymeric scaffolds obtained by the electrospinning process that has been applied for drug release in different mucosal sites such as oral, ocular, gastroenteric, vaginal, and nasal. We analyzed the electrospinning parameters that have to be optimized to create reproducible and efficient mucoadhesive nanofibers, among them are: electrical field, polymer concentration, viscosity, flow rate, needle-collector distance, solution conductivity, solvent, environmental parameters, and electrospinning setup. We also revised the mucoadhesive theories as well as the mucoadhesive properties of the polymers used. This review shows that the most studied mucosal site is the oral cavity, because it is accessible and easy to evaluate, while the rest are uncomfortable for the patient and difficult to assess in vivo. We found problems that need to be solved for mucoadhesive electrospun nanofibers, such as improving adhesion strength and mucosal permanence time, and the design of unidirectional release, multilayer systems for the treatment of several pathologies, to ensure the drug concentration in the tissue or target organ.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Muco/química , Nanofibras/química , Polímeros/química , Adesividade , Condutividade Elétrica , Humanos
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