RESUMO
BACKGROUND: Bacterial aromatic degradation may cause oxidative stress. The long-chain flavodoxin FldX1 of Paraburkholderia xenovorans LB400 counteracts reactive oxygen species (ROS). The aim of this study was to evaluate the protective role of FldX1 in P. xenovorans LB400 during the degradation of 4-hydroxyphenylacetate (4-HPA) and 3-hydroxyphenylacetate (3-HPA). METHODS: The functionality of FldX1 was evaluated in P. xenovorans p2-fldX1 that overexpresses FldX1. The effects of FldX1 on P. xenovorans were studied measuring growth on hydroxyphenylacetates, degradation of 4-HPA and 3-HPA, and ROS formation. The effects of hydroxyphenylacetates (HPAs) on the proteome (LC-MS/MS) and gene expression (qRT-PCR) were quantified. Bioaugmentation with strain p2-fldX1 of 4-HPA-polluted soil was assessed, measuring aromatic degradation (HPLC), 4-HPA-degrading bacteria, and plasmid stability. RESULTS: The exposure of P. xenovorans to 4-HPA increased the formation of ROS compared to 3-HPA or glucose. P. xenovorans p2-fldX1 showed an increased growth on 4-HPA and 3-HPA compared to the control strain WT-p2. Strain p2-fldX1 degraded faster 4-HPA and 3-HPA than strain WT-p2. Both WT-p2 and p2-fldX1 cells grown on 4-HPA displayed more changes in the proteome than cells grown on 3-HPA in comparison to glucose-grown cells. Several enzymes involved in ROS detoxification, including AhpC2, AhpF, AhpD3, KatA, Bcp, CpoF1, Prx1 and Prx2, were upregulated by hydroxyphenylacetates. Downregulation of organic hydroperoxide resistance (Ohr) and DpsA proteins was observed. A downregulation of the genes encoding scavenging enzymes (katE and sodB), and gstA and trxB was observed in p2-fldX1 cells, suggesting that FldX1 prevents the antioxidant response. More than 20 membrane proteins, including porins and transporters, showed changes in expression during the growth of both strains on hydroxyphenylacetates. An increased 4-HPA degradation by recombinant strain p2-fldX1 in soil microcosms was observed. In soil, the strain overexpressing the flavodoxin FldX1 showed a lower plasmid loss, compared to WT-p2 strain, suggesting that FldX1 contributes to bacterial fitness. Overall, these results suggest that recombinant strain p2-fldX1 is an attractive bacterium for its application in bioremediation processes of aromatic compounds. CONCLUSIONS: The long-chain flavodoxin FldX1 improved the capability of P. xenovorans to degrade 4-HPA in liquid culture and soil microcosms by protecting cells against the degradation-associated oxidative stress.
Assuntos
Burkholderia , Burkholderiaceae , Flavodoxina , Gliceraldeído/análogos & derivados , Fenilacetatos , Propano , Biodegradação Ambiental , Flavodoxina/metabolismo , Flavodoxina/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Proteoma/metabolismo , Proteoma/farmacologia , Cromatografia Líquida , Burkholderia/genética , Burkholderia/metabolismo , Espectrometria de Massas em Tandem , Estresse Oxidativo , Glucose/metabolismo , SoloRESUMO
Staphylococcus aureus is often associated worldwide with foodborne illnesses, and the elimination of biofilms formed by this bacterium from industrial surfaces is very challenging. To date, there have been few attempts to investigate plant oils obtained by recent green technologies, applied against biofilms on usual surfaces of the food industry and bacteria isolated from such environment. Therefore, this study evaluated the activity of Moringa oleifera seed oil (MOSO), extracted with pressurized n-propane, against standard and environmental S. aureus biofilms. Additionally, a genotypic and phenotypic study of the environmental S. aureus was proposed. It was found that this bacterium was a MSSA (methicillin-sensitive S. aureus), a carrier of icaA and icaD genes that has strong adhesion (OD550=1.86 ± 0.19) during biofilm formation. The use of pressurized n-propane as a solvent was efficient in obtaining MOSO, achieving a yield of 60.9%. Gas chromatography analyses revealed the presence of a rich source of fatty acids in MOSO, mainly oleic acid (62.47%), behenic acid (10.5%) and palmitic acid (7.32%). On polystyrene surface, MOSO at 0.5% and 1% showed inhibitory and bactericidal activity, respectively, against S. aureus biofilms. MOSO at 1% allowed a maximum reduction of 2.38 log UFC/cm² of S. aureus biofilms formed on PVC (polyvinyl chloride) surface. Scanning electron microscopy showed disturbances on the surface of S. aureus after exposure to MOSO. These unprecedented findings suggest that MOSO extracted with pressurized n-propane is potentially capable of inhibiting biofilms of different S. aureus strains, thus, contributing to microbiological safety during food processing.
Assuntos
Moringa oleifera , Staphylococcus aureus , Propano/farmacologia , Biofilmes , Óleos de Plantas/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
3-Hydroxypropionic acid (3HP) is a platform chemical and can be converted into other valuable C3-based chemicals. Because a large amount of glycerol is produced as a by-product in the biodiesel industry, glycerol is an attractive carbon source in the biological production of 3HP. Although eight 3HP-producing aldehyde dehydrogenases (ALDHs) have been reported so far, the low conversion rate from 3-hydroxypropionaldehyde (3HPA) to 3HP using these enzymes is still a bottleneck for the production of 3HP. In this study, we elucidated the substrate binding modes of the eight 3HP-producing ALDHs through bioinformatic and structural analysis of these enzymes and selected protein engineering targets for developing enzymes with enhanced enzymatic activity against 3HPA. Among ten AbKGSADH variants we tested, three variants with replacement at the Arg281 site of AbKGSADH showed enhanced enzymatic activities. In particular, the AbKGSADHR281Y variant exhibited improved catalytic efficiency by 2.5-fold compared with the wild type.
Assuntos
Azospirillum brasilense , Aldeído Desidrogenase/genética , Aldeído Desidrogenase/metabolismo , Azospirillum brasilense/genética , Azospirillum brasilense/metabolismo , Gliceraldeído/análogos & derivados , Glicerol/metabolismo , Engenharia Metabólica , Propano/metabolismo , Engenharia de ProteínasRESUMO
Aquaculture activities in southern Chile demand floating devices to produce electricity powered by diesel generators. It has been recently proposed to replace this fuel with propane. However, little is known about the behaviour and possible environmental impacts of an accidental release of propane underwater. In this study we evaluated the impact of water temperature and salinity on the saturation and further release of propane under controlled laboratory experiments. Results showed that under extreme environmentally relevant scenarios (high and low temperature and salinity), propane saturated the water more quickly. However, while it is important to consider that saturation times can be similar (â¼2 h), the magnitudes of propane dissolved can be different. Experiments showed that cold waters (5 °C) propane is dissolved twice than warm waters (20 °C). Residence time was more affected by water temperature and almost independent of water salinity. Propane may take at least 2 days to be released from waters (around 90% of the initial amount dissolved under laboratory conditions). Additionally, we evaluated the impact on dissolved oxygen displacement and the embryotoxicity of the dissolved fraction by using Zebrafish Embryo Toxicity Assay. Results showed that dissolved oxygen was quickly removed. However, the levels of dissolved oxygen were promptly recovered in the studied systems. We also observed that propane can generate genotoxic effects (3-10% mortality), but after 2 days the system can be almost free of propane and the effects may become much lower. Comparatively with the literature, propane showed to be less toxic than diesel and it is a viable and less environmentally hazardous replacement for diesel.
Assuntos
Propano , Peixe-Zebra , Animais , Chile , Meio Ambiente , Propano/toxicidade , SalinidadeRESUMO
BACKGROUND: Fungal infections are highly prevalent and are responsible for high rates of morbidity and mortality. In this context, the search for new treatment alternatives is very relevant. OBJECTIVES: Analyse chemical compounds for antifungal potential against dermatomycosis fungi. METHODS: The antifungal activity of 121 compounds, intermediates or derivatives of 1,3-bis(aryloxy)propane substituted at C-2 (111 compounds) and isothiouronium derivatives (10 compounds) was investigated through susceptibility tests, mechanism of action, toxicity and hydrogel incorporation. RESULTS: The compound 1,3-bis(3,4-dichlorophenoxy)propan-2-aminium chloride (2j) was the most active fungicide against dermatophytes and Candida spp., at very low concentrations (0.39-3.12 µg/mL), including action on resistant and multidrug-resistant clinical strains. Compound 2j has presented a promising toxicity profile, showing selectivity index >10, relative to human lymphocytes. The compound was classified as non-irritant by the HET-CAM test and did not cause histopathological alterations in pig ear skin, thus presenting an excellent perspective for topical application. 2j targets the fungal cell wall, which was confirmed by scanning electron microscopy, which also indicated the additional ability of 2j to inhibit the Candida albicans pseudohyphae formation and biofilm of Microsporum canis. Compound 2j was incorporated in a hydrogel with bioadhesive potential. The results of the human skin permeation showed that 2j remained significantly in the epidermis, ideally for the dermatomycosis treatment. CONCLUSIONS: Therefore, the compound 2j demonstrated the potential for antifungal drug development, with a action mechanism elucidated and already applied in a semisolid formulation as a new therapeutic option for fungal skin infections.
Assuntos
Antifúngicos/farmacologia , Arthrodermataceae/efeitos dos fármacos , Candida/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Propano/análogos & derivados , Animais , Antifúngicos/química , Sobrevivência Celular , Células Cultivadas , Galinhas , Membrana Corioalantoide/efeitos dos fármacos , Orelha Externa/efeitos dos fármacos , Epiderme/efeitos dos fármacos , Ergosterol/metabolismo , Feminino , Citometria de Fluxo , Humanos , Hidrogéis , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Masculino , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Propano/química , Propano/farmacologia , Reologia , Relação Estrutura-Atividade , SuínosRESUMO
Abstract This study aimed to develop and evaluate fermented milk by Lactobacillus reuteri LR92 with addition of juçara pulp (FMJ) and reuterin production in situ. The fermentation process was analyzed for 24 hours and the storage of FMJ for 30 days at 4 °C. During the fermentation, there was consumption of 25% (w / v) of lactose and increase of 0.01 to 0.85% (w / v) of lactic acid. The FMJ presented 0.43 ± 0.01 mM of reuterin, inhibiting Staphylococcus aureus strains under in vitro test. For the carbohydrates, the percentages (g.100g-1) found were 7.31 ± 1.07; 9.19 ± 0.82; 1.60 ± 0.50 and 0.08 ± 0.00 for sucrose, lactose, galactose and fructose respectively. The survival of L. reuteri, present in FMJ, was 2.47 log CFU / mL after 6 hours of gastrointestinal simulation. In sensory analysis FMJ received a grade 7 for global acceptance indicating good acceptance of the product.
Assuntos
Animais , Produtos Fermentados do Leite/microbiologia , Alimento Funcional/microbiologia , Limosilactobacillus reuteri/metabolismo , Euterpe/metabolismo , Propano/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Ácido Láctico , Anti-InfecciososRESUMO
This work aimed to produce ethyl esters from Chlorella vulgaris microalgae biomass, using an immobilized enzymatic catalyst associated with pressurized fluid (propane) by direct transesterification. In order to optimize the ethyl conversion, different temperatures (46.7-68.1 °C) and pressures (59.5-200.5 bar) were applied a central composite design rotational (CCDR) obtaining the high conversion (74.39%) at 50 °C and 180 bar. The molar ratio also was investigated showing conversions ~ 90% using a molar ratio of 1:24 (oil:ethanol). From the best transesterification conditions, 50 °C, 180 bar, 20% enzymatic concentration, and 1:24 oil:ethanol molar ratio were obtained with success 98.9% conversion in 7 h of reaction. The enzyme reuse maintained its activity for three successive cycles. Thus, this simple process was effective to convert microalgal biomass into ethyl ester by direct transesterification and demonstrate high yields.
Assuntos
Biomassa , Chlorella vulgaris/metabolismo , Ésteres/metabolismo , Microalgas/metabolismo , Pressão , Propano/metabolismo , Biocatálise , Biocombustíveis , Biotransformação , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Esterificação , Etanol/metabolismoRESUMO
Compounds containing a nitro group may reveal vasodilator properties. Several nitro compounds have a NO2 group in a short aliphatic chain connected to an aromatic group. In this study, we evaluated in rat aorta the effects of two nitro compounds, with emphasis on a putative recruitment of the soluble guanylate cyclase (sGC) pathway to induce vasodilation. Isolated aortic rings were obtained from male Wistar rats to compare the effects induced by 2-nitro-1-phenylethanone (NPeth) or 2-nitro-2-phenyl-propane-1,3-diol (NPprop). In aortic preparations contracted with phenylephrine or KCl, NPeth and NPprop induced vasorelaxant effects that did not depend on the integrity of vascular endothelium. NPeth had a lesser vasorelaxant efficacy than NPprop and only the NPprop effects were inhibited by pretreatment with the sGC inhibitors, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or methylene blue. In an ODQ-preventable manner, NPprop inhibited the contractile component of the phenylephrine-induced response mediated by intracellular Ca2+ release or by extracellular Ca2+ recruitment through receptor- or voltage-operated Ca2+ channels. In contrast, NPprop was inert against the transient contraction induced by caffeine in Ca2+-free medium. In an ODQ-dependent manner, NPprop inhibited the contraction induced by the protein kinase C activator phorbol 12,13-dibutyrate or by the tyrosine phosphatase inhibitor sodium orthovanadate. In silico docking analysis of a sGC homologous protein revealed preferential site for NPprop. In conclusion, the nitro compounds NPeth and NPprop induced vasorelaxation in rat aortic rings. Aliphatic chain substituents selectively interfered in the ability of these compounds to induce vasorelaxant effects, and only NPprop relaxed aortic rings via a sGC pathway.
Assuntos
Aorta Torácica/efeitos dos fármacos , Guanilato Ciclase/metabolismo , Nitrocompostos/farmacologia , Propano/análogos & derivados , Vasodilatadores/farmacologia , Animais , Aorta Torácica/fisiologia , Guanilato Ciclase/fisiologia , Masculino , Propano/farmacologia , Ratos WistarRESUMO
PURPOSE: Keratocystic odontogenic tumor (KCOT) is an aggressive benign tumor and the management by complete enucleation followed by cryotherapy maintains the inorganic bone matrix, resulting in better repair and reduces the rates of recurrence. A refrigerant spray with a propane/butane/isobutane gas mixture has been pointed to as an alternative to liquid nitrogen, because the device is easy to handle and contain within the cavity, providing better control and lower risk of injury to the adjacent soft tissue. Thus, the aim of this study was to evaluate the outcome of enucleation followed by cryosurgery using a refrigerant spray of this gas mixture in ten patients diagnosed with KCOT. METHOD: The biggest lesions received a prior treatment consisting of marsupialization to decrease the tumor size. During the surgeries, the lesions were removed by enucleation and the surgical site was sprayed with the gas mixture. RESULTS: Wound dehiscence was observed in all cases, which healed by the second intention. The mean follow-up period was 64.3 months (range 24-120 months). Eight of the ten patients showed no evidence of clinical or radiographic recurrence. Pathologic fractures and infections were not observed. CONCLUSIONS: The results obtained suggest that enucleation followed by cryosurgery is an effective therapy for managing KCOT.
Assuntos
Butanos/uso terapêutico , Criocirurgia/métodos , Neoplasias Mandibulares/cirurgia , Cistos Odontogênicos/cirurgia , Tumores Odontogênicos/cirurgia , Propano/uso terapêutico , Adolescente , Adulto , Aerossóis , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Liquefied hydrocarbon gas, such as propane is considered safe. However there are reports that voluntary exposure to liquefied gas at least could originate hallucinatory states. We report a 20 years old woman who was found in a coma with extensor muscle hypertonia, brisk tendon reflexes and extensor plantar (Babinski) responses after being exposed to propane gas. The brain magnetic resonance imaging (MRI) showed lesions in both hippocampi and white matter in the oval center. The patient had a normal oxygen saturation of 98%, a carboxyhemoglobin of 1.6% and a metabolic acidosis with a pH of 7.01 with an anion gap of 16 mEq/l. This pattern suggested that it was a consequence of the intermediary metabolism of isopropanol. The recovery of the patient was slow and four months later she still had lesions on MRI and limitations in her cognitive sphere, memory and executive functions. Thus, liquefied gas exposure can cause a toxic encephalopathy with a persistent damage of the central nervous system.
Assuntos
Exposição por Inalação/efeitos adversos , Síndromes Neurotóxicas/diagnóstico por imagem , Propano/intoxicação , Encéfalo/diagnóstico por imagem , Butanos/intoxicação , Feminino , Humanos , Imageamento por Ressonância Magnética , Adulto JovemRESUMO
Glycopentalone isolated from Glycosmis pentaphylla (family Rutaceae) has cytotoxic and apoptosis inducing effects in various human cancer cell lines; however, its mode of action is not known. Therefore, target fishing of glycopentalone using a combined approach of inverse docking and reverse pharmacophore mapping approach was used to identify potential targets of glycopentalone, and gain insight into its binding modes against the selected molecular targets, viz., CDK-2, CDK-6, Topoisomerase I, Bcl-2, VEGFR-2, Telomere:G-quadruplex and Topoisomerase II. These targets were chosen based on their key roles in the progression of cancer via regulation of cell cycle and DNA replication. Molecular docking analysis revealed that glycopentalone displayed binding energies ranging from -6.38 to -8.35 kcal/mol and inhibition constants ranging from 0.758 to 20.90 µM. Further, the binding affinities of glycopentalone to the targets were in the order: Telomere:G-quadruplex > VEGFR-2 > CDK-6 > CDK-2 > Topoisomerase II > Topoisomerase I > Bcl-2. Binding mode analysis revealed critical hydrogen bonds as well as hydrophobic interactions with the targets. The targets were validated by reverse pharmacophore mapping of glycopentalone against a set of 2241 known human target proteins which revealed CDK-2 and VEGFR-2 as the most favorable targets. The glycopentalone was well mapped to CDK-2 and VEGFR-2 which involve six pharmacophore features (two hydrophobic centers and four hydrogen bond acceptors) and nine pharmacophore features (five hydrophobic, two hydrogen bond acceptors and two hydrogen bond donors), respectively. The present computational approach may aid in rational identification of targets for small molecules against large set of candidate macromolecules before bioassays validation.
Assuntos
Antineoplásicos Fitogênicos/química , Propano/análogos & derivados , Pirróis/química , Sítios de Ligação , Quinase 2 Dependente de Ciclina/química , Quinase 6 Dependente de Ciclina/química , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Simulação de Acoplamento Molecular , Propano/química , Ligação Proteica , Rutaceae/química , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/químicaRESUMO
Liquefied hydrocarbon gas, such as propane is considered safe. However there are reports that voluntary exposure to liquefied gas at least could originate hallucinatory states. We report a 20 years old woman who was found in a coma with extensor muscle hypertonia, brisk tendon reflexes and extensor plantar (Babinski) responses after being exposed to propane gas. The brain magnetic resonance imaging (MRI) showed lesions in both hippocampi and white matter in the oval center. The patient had a normal oxygen saturation of 98%, a carboxyhemoglobin of 1.6% and a metabolic acidosis with a pH of 7.01 with an anion gap of 16 mEq/l. This pattern suggested that it was a consequence of the intermediary metabolism of isopropanol. The recovery of the patient was slow and four months later she still had lesions on MRI and limitations in her cognitive sphere, memory and executive functions. Thus, liquefied gas exposure can cause a toxic encephalopathy with a persistent damage of the central nervous system.
Assuntos
Humanos , Feminino , Adulto Jovem , Propano/intoxicação , Exposição por Inalação/efeitos adversos , Síndromes Neurotóxicas/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Butanos/intoxicação , Imageamento por Ressonância MagnéticaRESUMO
3-hydroxypropionaldehyde (3-HPA) and 1,3-propanediol (1,3-PD) are subproducts of glycerol degradation and of economical interest as they are used for polymers synthesis, such as polyesters and polyurethanes. Some few characterized bacterial species (mostly from Firmicutes and Gamma-proteobacteria groups) are able to catabolize these monomers from glycerol using the gene products from the dha regulon. To expand our knowledge and direct further experimental studies on the regulon and related genes for the anaerobic glycerol metabolism, an extensive genomic screening was performed to identify the presence of the dha genes in fully sequenced prokaryotic genomes. Interestingly, this work shows that although only few bacteria species are known to produce 3-HPA or 1,3-PD, the incomplete regulon is found in more than 100 prokaryotic genomes. However, the complete pathway is found only in a few dozen species belonging to five different taxonomic groups, including one Archaea species, Halalkalicoccus jeotgali. Phylogenetic analysis and conservation of both gene synteny and primary sequence similarity reinforce the idea that these genes have a common origin and were possibly acquired by lateral gene transfer (LGT). Besides the evolutionary aspect, the identification of homologs from several different organisms may predict potential alternative targets for faster or more efficient biological synthesis of 3-HPA or 1,3-PD.
Assuntos
Archaea/genética , Bactérias/genética , Evolução Molecular , Gliceraldeído/análogos & derivados , Propano/química , Propilenoglicóis/química , Regulon , Aerobiose , Algoritmos , Sequência de Aminoácidos , Fermentação , Transferência Genética Horizontal , Genoma Arqueal , Genoma Bacteriano , Genômica , Gliceraldeído/química , Glicerol/química , Glicerol/metabolismo , Funções Verossimilhança , Dados de Sequência Molecular , Filogenia , Homologia de Sequência de Aminoácidos , Especificidade da EspécieRESUMO
Flaxseed (Linum usitatissimum L.) oil was obtained via subcritical n-propane fluid extraction (SubFE) under different temperatures and pressures with an average yield of 28% and its composition, purity and oxidative stability were compared to oils obtained via conventional solvent extraction methods (SEMs). When the oxidative stability was measured by differential scanning calorimetry, the oil was found to be up to 5 times more resistant to lipid oxidation as compared to the SEM oils. Direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis showed characteristic and similar TAG profiles for SubFE and SEMs oils but higher purity for the SubFE oil. The flaxseed oil content of ß-tocopherol, campesterol, stigmasterol and sitosterol were quantified via GC-MS. SubFE showed to be a promising alternative to conventional SEM since SubFE provides an oil with higher purity and higher oxidation stability and with comparable levels of biologically active components.
Assuntos
Fracionamento Químico/métodos , Óleo de Semente do Linho/análise , Óleo de Semente do Linho/química , Propano/química , Varredura Diferencial de Calorimetria , Colesterol/análogos & derivados , Colesterol/análise , Cromatografia Gasosa-Espectrometria de Massas , Óleo de Semente do Linho/normas , Oxirredução , Fitosteróis/análise , Pressão , Análise de Componente Principal , Sitosteroides/análise , Espectrometria de Massas por Ionização por Electrospray , Estigmasterol/análise , Temperatura , beta-Tocoferol/análiseRESUMO
In the title compound, C26H20ClNO3, the quinoline fragment is nearly orthogonal to the adjacent aryl ring, while the rest of the molecular skeleton is close to being planar. The crystal structure contains no hydrogen bonds of any sort, but there are two π-π stacking interactions present. One, involving the quinoline ring, links molecules related by inversion, while the other, involving the two nonfused aryl rings, links molecules related by translation, so together forming a ladder-type arrangement.
Assuntos
Propano/análogos & derivados , Quinolinas/química , Cristalografia por Raios X , Ligação de Hidrogênio , Estrutura Molecular , Propano/químicaRESUMO
The search for new nitric oxide donors is warranted by the limitations of organic nitrates currently used in cardiology. The new organic nitrate 2-nitrate-1,3-dibuthoxypropan (NDBP) exhibited promising cardiovascular activities in previous studies. The aim of this study was to investigate the cardiorespiratory responses evoked by NDBP and to compare them to the clinically used organic nitrate nitroglycerine (NTG). Arterial pressure, heart rate and respiration were recorded in conscious adult male Wistar rats. Bolus i.v. injection of NDBP (1 to 15mg/kg; n=8) and NTG (0.1 to 5mg/kg; n=8) produced hypotension. NDBP induced bradycardia at all doses, while NTG induced tachycardia at three lower doses but bradycardia at higher doses. Hydroxocobalamin (20mg/kg; HDX), a NO scavenger, blunted hypotension induced by NDBP (15mg/kg), and its bradycardic effect (n=6). In addition, HDX blunted both hypotension and bradycardia induced by a single dose of NTG (2.5mg/kg; n=6). Both NDBP and NTG altered respiratory rate, inducing a biphasic effect with a bradypnea followed by a tachypnea; HDX attenuated these responses. Our data indicate that NDBP and NTG induce hypotension, bradycardia and bradypnea, which are mediated by nitric oxide release.
Assuntos
Pressão Arterial/efeitos dos fármacos , Fármacos Cardiovasculares/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Nitratos/farmacologia , Propano/análogos & derivados , Respiração/efeitos dos fármacos , Animais , Pressão Arterial/fisiologia , Bradicardia/induzido quimicamente , Bradicardia/tratamento farmacológico , Bradicardia/fisiopatologia , Fármacos Cardiovasculares/administração & dosagem , Estado de Consciência , Relação Dose-Resposta a Droga , Frequência Cardíaca/fisiologia , Hidroxocobalamina/farmacologia , Hipotensão/induzido quimicamente , Hipotensão/tratamento farmacológico , Hipotensão/fisiopatologia , Masculino , Nitratos/administração & dosagem , Óxido Nítrico/metabolismo , Nitroglicerina/administração & dosagem , Nitroglicerina/farmacologia , Propano/administração & dosagem , Propano/farmacologia , Ratos , Ratos Wistar , Taquipneia/induzido quimicamente , Taquipneia/tratamento farmacológico , Taquipneia/fisiopatologia , Vasodilatadores/administração & dosagem , Vasodilatadores/farmacologiaRESUMO
Dehalococcoides mccartyi strains KS and RC grow with 1,2-dichloropropane (1,2-D) as an electron acceptor in enrichment cultures derived from hydrocarbon-contaminated and pristine river sediments, respectively. Transcription, expression, enzymatic, and PCR analyses implicated the reductive dehalogenase gene dcpA in 1,2-D dichloroelimination to propene and inorganic chloride. Quantitative real-time PCR (qPCR) analyses demonstrated a D. mccartyi cell increase during growth with 1,2-D and suggested that both D. mccartyi strains carried a single dcpA gene copy per genome. D. mccartyi strain RC and strain KS produced 1.8 × 10(7) ± 0.1 × 10(7) and 1.4 × 10(7) ± 0.5 × 10(7) cells per µmol of propene formed, respectively. The dcpA gene was identified in 1,2-D-to-propene-dechlorinating microcosms established with sediment samples collected from different geographical locations in Europe and North and South America. Clone library analysis revealed two distinct dcpA phylogenetic clusters, both of which were captured by the dcpA gene-targeted qPCR assay, suggesting that the qPCR assay is useful for site assessment and bioremediation monitoring at 1,2-D-contaminated sites.
Assuntos
Alcenos/metabolismo , Chloroflexi/enzimologia , Hidrolases/metabolismo , Propano/análogos & derivados , Chloroflexi/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , Europa (Continente) , Perfilação da Expressão Gênica , Hidrolases/genética , Dados de Sequência Molecular , América do Norte , Filogenia , Propano/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , América do Sul , Microbiologia da ÁguaRESUMO
This study evaluated the results of curettage followed by cryosurgery using a combination of propane, butane, and isobutane gas for several benign but locally aggressive bone tumours on the mandible. Twenty-nine patients (16 men and 13 women) participated in the study. Patient ages ranged from 6 to 87 years (mean, 23.72 years). Before enucleation and cryosurgery, some patients received prior treatment consisting of marsupialisation to decrease tumour size. Twenty-seven of the 29 patients (93.10%) showed no evidence of clinical or radiographic recurrence after treatment through enucleation and cryosurgery. Wound dehiscence, which was observed in all cases, healed by second intention. The average follow-up period was 70.55 months (range, 53-120 months). These results suggest that enucleation followed by cryosurgery is an effective therapy for managing locally aggressive mandible tumours. In addition, this treatment is a less expensive intervention than more radical procedures.
Assuntos
Butanos/uso terapêutico , Criocirurgia/métodos , Neoplasias Mandibulares/cirurgia , Propano/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ameloblastoma/cirurgia , Criança , Curetagem/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tumores Odontogênicos/cirurgia , Estudos Retrospectivos , Deiscência da Ferida Operatória/etiologia , Cicatrização/fisiologia , Adulto JovemRESUMO
Chromium and ruthenium-doped zinc oxide (ZnO:Cr) and (ZnO:Ru) thin solid films were deposited on soda-lime glass substrates by the sol-gel dip-coating method. A 0.6 M solution of zinc acetate dihydrate dissolved in 2-methoxyethanol and monoethanolamine was used as basic solution. Chromium (III) acetylacetonate and Ruthenium (III) trichloride were used as doping sources. The Ru incorporation and its distribution profile into the films were proved by the SIMS technique. The morphology and structure of the films were studied by SEM microscopy and X-ray diffraction measurements, respectively. The SEM images show porous surfaces covered by small grains with different grain size, depending on the doping element, and the immersions number into the doping solutions. The sensing properties of ZnO:Cr and ZnO:Ru films in a propane (C3H8) atmosphere, as a function of the immersions number in the doping solution, have been studied in the present work. The highest sensitivity values were obtained for films doped from five immersions, 5.8 and 900, for ZnO:Cr and ZnO:Ru films, respectively. In order to evidence the catalytic effect of the chromium (Cr) and ruthenium (Ru), the sensing characteristics of undoped ZnO films are reported as well.
Assuntos
Cromo/química , Propano/isolamento & purificação , Rutênio/química , Óxido de Zinco/química , Catálise , Géis , Vidro/química , Humanos , Transição de Fase , Soluções/química , Propriedades de Superfície , Difração de Raios XRESUMO
Commercial inulinase from Aspergillus niger was immobilized in montmorillonite and then treated in pressurized propane and liquefied petroleum gas (LPG). Firstly, the effects of system pressure, exposure time, and depressurization rate, using propane and LPG, on enzymatic activity were evaluated through central composite design 2³. Residual activities of 145.1 and 148.5% were observed for LPG (30 bar, 6 h, and depressurization rate of 20 bar min⻹) and propane (270 bar, 1 h, and depressurization rate of 100 bar min⻹), respectively. The catalysts treated at these conditions in both fluids were then used for the production of fructooligosaccharides (FOS) using sucrose and inulin as substrates in aqueous and organic systems. The main objective of this step was to evaluate the yield and productivity in FOS, using alternatives for enhancing enzyme activity by means of pressurized fluids and also using low-cost supports for enzyme immobilization, aiming at obtaining a stable biocatalyst to be used for synthesis reactions. Yields of 18% were achieved using sucrose as substrate in aqueous medium, showing the potential of this procedure, hence suggesting a further optimization step to increase the process yield.