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1.
Eur J Neurosci ; 54(4): 5507-5517, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34237172

RESUMO

Respiratory modulation of forebrain activity, long considered hard to reliably separate from breathing artefacts, has been firmly established in recent years using a variety of advanced techniques. Respiratory-related oscillation (RRO) is derived from rhythmic nasal airflow in the olfactory bulb (OB) and is conveyed to higher order brain networks, including the prefrontal cortex (PFC) and hippocampus (HC), where it may potentially contribute to communication between these structures by synchronizing their activities at the respiratory rate. RRO was shown to change with sleep-wake states; it is strongest in quiet waking, somewhat less in active waking, characterized with theta activity in the HC, and absent in sleep. The goal of this study was to test RRO synchronization between PFC and HC under urethane anaesthesia where theta and non-theta states spontaneously alternate. We found that in theta states, PFC-HC coherences significantly correlated with OB-HC but not with OB-PFC, even though RRO was stronger in PFC than in HC. In non-theta states, PFC-HC synchrony correlated with coherences connecting OB to either PFC or HC. Thus, similar to freely behaving rats, PFC-HC synchrony at RRO was primarily dependent on the response of HC to the common rhythmic drive, but only in theta state. The findings help outlining the value and the limits of applications in which urethane-anaesthetized rats can be used for modelling the neural mechanisms of RRO in behaving animals.


Assuntos
Ritmo Teta , Uretana , Animais , Hipocampo , Córtex Pré-Frontal , Ratos , Sono
2.
Mater Sci Eng C Mater Biol Appl ; 127: 112194, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225848

RESUMO

A strategy to enhance drug effectiveness while minimizing controversial effects consists in exploiting host-guest interactions. Moreover, these phenomena can induce the self-assembly of physical hydrogels as effective tools to treat various pathologies (e.g., chronic wounds or cancer). Here, two Poloxamers®/Pluronics® (P407/F127 and P188/F68) were utilized to synthesize various LEGO-like poly(ether urethane)s (PEUs) to develop a library of tunable and injectable supramolecular hydrogels for drug delivery. Three PEUs were synthesized by chain extending Poloxamer/Pluronic with 1,6-cyclohexanedimethanol or N-Boc serinol. Other two amino-functionalized and highly responsive polymers were obtained thorough Boc-group cleavage. For hydrogel design, the spontaneous self-assembly of the poly(ethylene oxide) domains of PEUs with α-cyclodextrins was exploited to form poly(pseudo)rotaxanes (PPRs). PPR-derived channel-like crystals were characterized by X-Ray powder diffraction, Infra-Red and Proton Nuclear Magnetic Resonance spectroscopies. Cytocompatible hydrogel formulations were designed at PEU concentrations between 1% and 5% w/v and α-cyclodextrin at 10% w/v. Supramolecular gels showed good mechanical performances (storage modulus up to 20 kPa) coupled with marked thixotropic and self-healing properties (mechanical recovery over 80% within 30 s after cyclic rupture) as assessed through rheology. Hydrogels exhibited stability and high responsiveness in watery environment up to 5 days: the release of less stable components as suitable drug carriers was coupled with high swelling (doubling the content of fluids with respect to their dry mass) and shape retention. Curcumin was encapsulated into the hydrogels at high concentration (80 µg ml-1) through its complexation with α-cyclodextrins and delivery tests showed controllable and progressive release profiles up to four days.


Assuntos
Curcumina , alfa-Ciclodextrinas , Éter , Hidrogéis , Polietilenoglicóis , Uretana
3.
Appl Microbiol Biotechnol ; 105(11): 4383-4395, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34021810

RESUMO

Ethyl carbamate (EC) is a genotoxic and carcinogenic compound that is also a by-product of fermented foods (bread, sour milk, soy cheese, etc.) and alcoholic beverages (wine, sake, distilled liquor, etc.). Studies have showed that ethyl carbamate is ingested by humans primarily through the consumption of alcoholic beverages. Many countries have thus established EC limits for alcoholic beverages. Chinese liquor (Baijiu) is a traditional and unique distilled liquor, which has a huge consumption in China due to its excellent color, flavor, and taste. Therefore, the control of EC in Chinese liquor is of great significance. This review summarized for the first time the progress in presence level, analysis method, formation mechanism, and elimination strategy of EC of Chinese liquor in recent decades. KEY POINTS: • GC-MS and HPLC are the main methods to quantify EC in Chinese liquor. • EC is formed in the fermentation, distillation, and storage stage. • EC content can be reduced from raw material, microorganism, and production process.


Assuntos
Uretana , Vinho , Bebidas Alcoólicas/análise , China , Fermentação , Aromatizantes , Humanos , Uretana/análise , Vinho/análise
4.
J Nanosci Nanotechnol ; 21(7): 3980-3983, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33715729

RESUMO

New thermal-latent metal catalyst such as tetrakis (lauorate) titanium (LPTi) was designed and synthesized based on a lauroyl peroxide and titanium. The synthetic method is simple with one step reaction. LPTi structure was confirmed by FT-IR analysis, also nano-sized structure of LPTi confirmed using SEM-EDX. LPTi is thermal-latent metal catalyst including titanium that not only promotes urethane synthesis reaction but also increases the dissociation rate of blocked isocyanate. As a result of quantitative analysis of NCO (%) through back titration, when LPTi was added, NCO (%) increased from 2.34% to 3.24%. LPTi can be used as an excellent catalyst for urethane reaction by reducing the polymerization time by about 30% compared to no catalyst. LPTi can be applied to the electronic polymer synthesis.


Assuntos
Titânio , Uretana , Ligantes , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier
5.
Molecules ; 26(4)2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-33670043

RESUMO

The aim of this study was to investigate and understand bacterial adhesion to different dental material surfaces like amalgam, Chromasit, an Co-Cr alloy, an IPS InLine ceramic, yttrium stabilized tetragonal polycrystalline zirconia (TPZ), a resin-based composite, an Au-Pt alloy, and a tooth. For all materials, the surface roughness was assessed by profilometry, the surface hydrophobicity was determined by tensiometry, and the zeta potential was measured by electrokinetic phenomena. The arithmetic average roughness was the lowest for the TPZ ceramic (Ra = 0.23 µm ± 0.02 µm), while the highest value was observed for the Au-Pt alloy (Ra = 0.356 µm ± 0.075 µm). The hydrophobicity was the lowest on the TPZ ceramic and the highest on the Co-Cr alloy. All measured streaming potentials were negative. The most important cause of tooth caries is the bacterium Streptococcus mutans, which was chosen for this study. The bacterial adhesion to all material surfaces was determined by scanning electron microscopy. We showed that the lowest bacterial extent was on the amalgam, whereas the greatest extent was on tooth surfaces. In general, measurements showed that surface properties like roughness, hydrophobicity and charge have a significant influence on bacterial adhesion extent. Therefore, dental material development should focus on improving surface characteristics to reduce the risk of secondary caries.


Assuntos
Ligas/química , Cerâmica/química , Resinas Compostas/química , Amálgama Dentário/química , Metacrilatos/química , Streptococcus mutans/crescimento & desenvolvimento , Uretana/química , Aderência Bacteriana , Humanos , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Propriedades de Superfície
6.
Eur J Cardiothorac Surg ; 59(5): 1048-1056, 2021 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-33538794

RESUMO

OBJECTIVES: Transcatheter pulmonary valve replacement has become a valid treatment option for right ventricular outflow tract diseases. However, some limitations occur in patients with wide, compliant right ventricular outflow tracts that might be amenable to treatment with self-expanding valved protheses. An experimental ovine study was designed to evaluate a novel dip-coated, low-profile trileaflet polycarbonate urethane (PCU) heart valve mounted into a self-expandable nitinol stent. METHODS: The PCU valves were produced by a dip-coating technique, mounted in a conical-shaped nitinol stent and provided with a leaflet thickness of 100-150 µm. The valved stents were implanted percutaneously via transfemoral access in 6 consecutive sheep divided into 2 groups. Three animals were followed up for 1 month and the remainder, for 6 months. Angiographic measurements and transthoracic echocardiography were performed before and after implantation and at the end of the 1- or 6-month observation period, respectively. RESULTS: Orthotopic positioning of the valve was achieved in all animals. All except 1 had competent valves during the follow-up period. The peak-to-peak gradient across the PCU valved stents was 4.6 ± 1.0 mmHg after 1 month and 4.4 ± 2.3 mmHg after 6 months of follow-up. Macroscopic and microscopic post-mortem evaluation indicated good morphological and structural results. There were no stent fractures, leaflet calcification or thrombus formation. CONCLUSIONS: This study demonstrates successful transcatheter pulmonary valve replacement with a novel dip-coated valved nitinol stent. The trileaflet PCU prostheses indicated good functional and biocompatible properties after a 6-month observation period.


Assuntos
Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Valva Pulmonar , Animais , Humanos , Cimento de Policarboxilato , Desenho de Prótese , Valva Pulmonar/cirurgia , Ovinos , Stents , Uretana
7.
J Hazard Mater ; 406: 124288, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33525128

RESUMO

Ethyl carbamate is a group of 2A carcinogen ubiquitously existed in fermented foods. The monitoring of its residues was important for evaluating the potential risk to human beings. Immunoassays with good accuracy and simplicity are great analytical tools for small molecule contaminants. However, it is typically confined in a competitive mode for small molecules with drawback of the sensitivity curbing. In this work, three different phages displayed peptides with capability of identifying the xanthyl ethyl carbamate immunocomplex were isolated from phage library. The binding mechanism of peptides and immunocomplex was studied by computer-assisted simulation. Results indicated that the xanthydrol group of xanthyl ethyl carbamate and the Asn-32 and Asn-92 residues of the antibody light chain were mainly responsible for binding. Simultaneously, a sensitive non-competitive immunoassay for detecting ethyl carbamate in wine samples was developed. The established method exhibited a limit of detection of 5.4 ng/mL and a linear range from 8.7 ng/mL to 32 ng/mL for wine samples. In comparison with the conventional competitive immunoassay, the sensitivity of the proposed non-competitive immunoassay was improved by 17-fold. The results of the immunoassay were validated by a standard ultra-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry, which illustrated good reliability of the proposed assay.


Assuntos
Uretana , Vinho , Humanos , Imunoensaio , Peptídeos , Reprodutibilidade dos Testes , Vinho/análise
8.
Mater Sci Eng C Mater Biol Appl ; 121: 111857, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33579489

RESUMO

Biodegradable strain sensors able to undergo controlled degradation following implantation have recently received significant interest as novel approaches to detect pathological tissue swelling or non-physiological stresses. In this study, the physicomechanical, electrochemical and active pressure sensing behavior of an electrically conductive and biodegradable poly(glycerol sebacate urethane) (PGSU) composite, reinforced with poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) functionalized carbon nanotubes (CNTs), was evaluated in vitro. Analysis of these PGSU-CNTs composites demonstrated that the incorporation of functionalized CNTs into a biodegradable elastomer resulted in enhanced mechanical strength, conductivity and tailored matrix biodegradation. PGSU-CNT composites were subsequently formulated into flexible and active pressure sensors which demonstrated optimal sensitivity to applied 1% uniaxial tensile strains. Finally, cytocompatibility analysis a with primary neural culture confirmed that PGSU-CNT composites exhibited low cytotoxicity, and supported neuron adhesion, viability, and proliferation in vitro.


Assuntos
Nanotubos de Carbono , Compostos Bicíclicos Heterocíclicos com Pontes , Glicerol , Polímeros , Uretana
9.
Anal Chim Acta ; 1151: 338256, 2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33608078

RESUMO

Traditional enzyme-linked immunosorbent assay (t-ELISA) method suffers from its relatively low sensitivity or accuracy in the detection of trace level of analyte in complicated samples. In this work, to extend the application of ELISA in practical samples, a newly electrochemical immunoassay (ECIA) was developed based on an enzyme-induced Cu2+/Cu+ conversion for the determination of ethyl carbamate (EC). Wherein, three rounds of signal transformation-the catalysis of ALP enzyme, the conversion of Cu2+/Cu+ and signal output of square wave voltammetry (SWV), can be realized to obtain higher sensitivity as compared to t-ELISA. The ECIA method combines the advantages of electrochemistry and ELISA, behaving superior detection performance, such as good selectivity, high sensitivity, and low background signal. For the wine samples, the method showed a linear detection range from 2.5 nM to 2.5 × 104 nM with a limit of detection of 2.28 nM (S/N = 3), which reveals that the ECIA sensor is a promising platform for the detection of trace level of EC in practical samples.


Assuntos
Técnicas Eletroquímicas , Uretana , Cobre , Ensaio de Imunoadsorção Enzimática , Imunoensaio , Limite de Detecção
10.
J Sci Food Agric ; 101(3): 1143-1149, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32789849

RESUMO

BACKGROUND: Different red winemaking were carried out to evaluate the effects of the prefermentative addition of chitosan, as an alternative to the use of SO2 , on the secondary products of alcoholic fermentation, yeast available nitrogen (YAN), biogenic amines and ethyl carbamate. RESULTS: The wines made with chitosan presented higher total acidity and higher content of tartaric and succinic acids than those made only with SO2 . The use of chitosan in winemaking resulted in wines with higher glycerol and diacetyl content without increasing the concentration of ethanol, acetic acid, acetaldehyde or butanediol. YAN was lower in wines made with chitosan, which may mean an advantage for the microbial stability of the wines. Furthermore, the use of chitosan at the beginning of alcoholic fermentation did not increase the concentration of biogenic amines or the formation of ethyl carbamate in SO2 -free red wines. CONCLUSION: The total or partial substitution of SO2 for chitosan at the beginning of the alcoholic fermentation gives rise to quality red wines without negatively affecting their nitrogen fraction or their very important secondary fermentation products such as acetic acid or acetaldehyde. © 2020 Society of Chemical Industry.


Assuntos
Quitosana/metabolismo , Nitrogênio/metabolismo , Saccharomyces cerevisiae/metabolismo , Dióxido de Enxofre/análise , Vitis/química , Vinho/análise , Acetaldeído/análise , Acetaldeído/metabolismo , Ácido Acético/análise , Ácido Acético/metabolismo , Aminas Biogênicas/análise , Aminas Biogênicas/metabolismo , Quitosana/análise , Etanol/análise , Etanol/metabolismo , Fermentação , Manipulação de Alimentos , Nitrogênio/análise , Metabolismo Secundário , Uretana/análise , Uretana/metabolismo , Vitis/metabolismo , Vitis/microbiologia
11.
Arch Gynecol Obstet ; 303(1): 181-188, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33146769

RESUMO

PURPOSE: Postoperative seromas are a problem in the surgical treatment of breast cancer. The aim of the study was to evaluate whether the lysine-urethane-based tissue adhesive TissuGlu® without drainage is equal/ non-inferior to standard mastecomy with drainage. METHODS: The study was designed as a prospective, randomized, multicentre non-inferiority study comparing the use of TissuGlu® without drainage with standard wound care with a drain insertion in ablative breast procedures. The number of clinical interventions, quality of life and wound complications were followed-up for 90 days in both groups. RESULTS: Although the statistical power was not reached, twice as many clinical interventions were performed in the TissuGlu® group than in the drainage group, especially aspirations of clinically relevant seromas (p = 0.014). The TissuGlu® group produced overall less wound fluid, but developed a clinically relevant seroma (100% vs. 63%) which made an intervention necessary. Less hospitalisation time was observed in the TissuGlu® group, but the complication rate was higher. There was no significant difference in regards to postoperative pain. In summary the non-inferiority of TissuGlu® compared to standard drainage couldn't be reached. DISCUSSION: The present evaluation shows no advantage of the tissue adhesive TissuGlu® in terms of seroma formation and frequency of intervention compared to a standard drainage for mastectomies, but the shorter inpatient stay certainly has a positive effect on the quality of life.


Assuntos
Neoplasias da Mama/cirurgia , Mastectomia/métodos , Procedimentos Cirúrgicos Reconstrutivos/efeitos adversos , Seroma/prevenção & controle , Fita Cirúrgica , Técnicas de Sutura/efeitos adversos , Adesivos Teciduais/uso terapêutico , Adulto , Neoplasias da Mama/patologia , Drenagem/métodos , Feminino , Humanos , Lisina/química , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Qualidade de Vida , Seroma/epidemiologia , Seroma/etiologia , Aderências Teciduais , Adesivos Teciduais/química , Resultado do Tratamento , Uretana/química
12.
Am J Physiol Heart Circ Physiol ; 320(1): H117-H132, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33216622

RESUMO

Elevated renal afferent nerve (ARNA) activity or dysfunctional reno-renal reflexes via altered ARNA sensitivity contribute to hypertension and chronic kidney disease. These nerves contain mechano- and chemosensitive fibers that respond to ischemia, changes in intrarenal pressures, and chemokines. Most studies have utilized various anesthetized preparations and exclusively male animals to characterize ARNA responses. Therefore, this study assessed the impact of anesthesia, sex, and circadian period on ARNA responses and sensitivity. Multifiber ARNA recordings were performed in male and female Sprague-Dawley rats (250-400 g) and compared across decerebrate versus Inactin, isoflurane, and urethane anesthesia groups. Intrarenal artery infusion of capsaicin (0.1-50.0 µM, 0.05 mL) produced concentration-dependent increases in ARNA; however, the ARNA sensitivity was significantly greater in decerebrate versus Inactin, isoflurane, and urethane groups. Increases in renal pelvic pressure (0-30 mmHg, 30 s) produced pressure-dependent increases in ARNA; however, ARNA sensitivity was again greater in decerebrate and Inactin groups versus isoflurane and urethane. Acute renal artery occlusion (30 s) increased ARNA, but responses did not differ across groups. Analysis of ARNA responses to increased pelvic pressure between male and female rats revealed significant sex differences only in isoflurane and urethane groups. ARNA responses to intrarenal capsaicin infusion were significantly blunted at nighttime versus daytime; however, ARNA responses to increased pelvic pressure or renal artery occlusion were not different between daytime and nighttime. These results demonstrate that ARNA sensitivity is greatest in decerebrate and Inactin-anesthetized groups but was not consistently influenced by sex.NEW & NOTEWORTHY We determined the impact of anesthesia, sex, and circadian cycle on renal afferent nerve (ARNA) sensitivity to chemical and mechanical stimuli. ARNA sensitivity to renal capsaicin infusion was greatest in decerebrate > Inactin > urethane or isoflurane groups. Elevated renal pelvic pressure significantly increased ARNA; decerebrate and Inactin groups exhibited the greatest ARNA sensitivity. Sex differences in renal afferent responses were not consistently observed. Circadian cycle altered chemosensory but not mechanosensory responses.


Assuntos
Potenciais de Ação/efeitos dos fármacos , Anestésicos Inalatórios/farmacologia , Anestésicos Intravenosos/farmacologia , Capsaicina/farmacologia , Ritmo Circadiano , Rim/irrigação sanguínea , Neurônios Aferentes/efeitos dos fármacos , Fármacos do Sistema Sensorial/farmacologia , Animais , Estado de Descerebração , Relação Dose-Resposta a Droga , Feminino , Hemodinâmica/efeitos dos fármacos , Isoflurano/farmacologia , Masculino , Pressão , Ratos Sprague-Dawley , Fatores Sexuais , Tiopental/análogos & derivados , Tiopental/farmacologia , Fatores de Tempo , Uretana/farmacologia
13.
Food Chem ; 343: 128528, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33189477

RESUMO

Ethyl carbamate (EC), a genotoxic and carcinogenic compound in soy sauce accumulated during thermal processes, has raised public health concern for its multipoint potential carcinogenic risk to human. In this work, based on the analysis of EC accumulation during thermal processes of soy sauce, ornithine and quercetin were added before thermal processes to reduce EC accumulation. A reduction rate of 23.7-63.8% in simulated solution was founded. Kinetic studies indicated that ornithine was a byproduct of alcoholysis reaction when EC formed, while quercetin could compete with the precursor ethanol and react with carbamyl compounds, which therefore preventedEC accumulation. A maximum of 47.2% decrease of EC in soy sauce was achieved, and no remarkable changes in volatile compounds profile and color of soy sauce were found. In conclusion, the addition of quercetin and ornithine before thermal processes may be preferable for the controlling of EC content in soy sauce.


Assuntos
Ornitina/química , Quercetina/química , Alimentos de Soja , Uretana/química , Carcinógenos/química , Etanol/química , Fermentação , Qualidade dos Alimentos , Humanos , Concentração de Íons de Hidrogênio , Cinética , Alimentos de Soja/análise , Uretana/análise
14.
Food Chem ; 337: 127954, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32919268

RESUMO

Lipases are associated with food spoilage and are also used in various biotechnological applications. In this study, we sought to purify, identify, and characterize a lipase from S. liquefaciens isolated from cold raw cow's milk. The lipase partially purified by ultrafiltration and gel filtration showed a specific activity of 2793 U/mg. By zymography, the enzyme presented approximately 65 kDa, and LC-MS/MS allowed the identification of a polyurethanase with a conserved domain of family I.3 lipase. The modeled and validated structure of polyurethanase was able to bind to different fatty acids and urethane by molecular docking. The polyurethanase showed optimum activity at pH 8.0 and 30 °C. In the presence of ions, activity was decreased, except for Ca2+, Mg2+, and Ba2+. Reducing agents did not alter the activity, while amino acid modifiers reduced enzyme activity. It is concluded that polyurethanase with lipase activity represents a potential enzyme for the deterioration of milk and dairy products, as well as a candidate for industrial applications.


Assuntos
Lipase/metabolismo , Leite/microbiologia , Serratia liquefaciens/enzimologia , Animais , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Bovinos , Cromatografia em Gel , Cromatografia Líquida , Ácidos Graxos/metabolismo , Feminino , Lipase/isolamento & purificação , Simulação de Acoplamento Molecular , Conformação Proteica , Espectrometria de Massas em Tandem , Uretana/metabolismo
15.
Biomed Res Int ; 2020: 2981681, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33274201

RESUMO

Ethyl-4-bromophenyl-carbamate (LQM 919) and Ethyl-4-chlorophenyl-carbamate (LQM 996) are compounds that inhibit egg-laying and hatching of tick larvae that are resistant to conventional ixodicides. The structure-activity relationship (SAR) to get the endpoint predictions of mutagenicity and carcinogenicity of the LQM 919 and LQM 996 was performed and the absence of mutagenicity was confirmed by Ames test. SAR analysis show no structural alerts indicating the ability of ethyl-carbamates to bind biomolecules or estrogen receptors. Endpoint of mutagenicity with and without metabolic activation showed that the ethyl-carbamates were negative (p <0.05) for mutagenicity induction in strains TA97, TA98, TA102, TA1535, TA1537 and TA1538 of Salmonella typhimurium. Pre-incubation with different ethyl-carbamate concentrations did not increase the number of spontaneously reverting colonies; moreover, the compounds did not induce a concentration-dependent increase in the number of reverting colonies in any of the strains used. This confirmed the absence of mutagenic activity in this test system. Exogenous metabolic activation did not modify these observations; suggesting that no metabolites with mutagenic activity were present. The endpoint of carcinogenicity in rats were negative for LQM 919 (p <0.05,) and LQM 996 (p <0.001). The results of the present study strongly suggest that ethyl-carbamates do not represent a risk for cancer in mammals.


Assuntos
Carcinógenos/química , Carcinógenos/toxicidade , Ixodidae/efeitos dos fármacos , Mutagênicos/química , Mutagênicos/toxicidade , Uretana/química , Uretana/toxicidade , Animais , Salmonella typhimurium/efeitos dos fármacos , Relação Estrutura-Atividade
16.
Food Funct ; 11(12): 10317-10328, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33215619

RESUMO

Ethyl carbamate (EC) is an environmental toxin, commonly present in various fermented foods and beverages, as well as tobacco and polluted ambient air. However, studies on the effects of EC-induced toxicity on the intestines and potential protection methods are limited. In this study, we show that EC could cause severe toxicity in intestinal epithelial cells (IECs) triggering the induction of decreased cell viability, ROS accumulation and glutathione (GSH) depletion in a dose-dependent manner. Based on these results, we established an EC-treated IEC model to screen the potential protective effects of 12 kinds of anthocyanins extracted from blueberry. Interestingly, we found that malvidin-3-O-arabinoside (M3A) significantly reversed the oxidative damage caused by EC exposure by stimulating autophagy flux, which was determined by the LC3-II level and GFP-RFP-LC3 transfection experiment. Enhancement of autophagy was mainly ascribed to the regulation of lysosomes. M3A pretreatment remarkably upregulated LAMP-1 expression, which indicated elevated lysosomal mass. Besides, M3A also successfully restored lysosomal acidity and subsequently strengthened lysosomal functions. Furthermore, M3A stimulated phosphorylation of AMP-activated protein kinase (AMPK), a master regulator of autophagy. Furthermore, our study indicated the possibility of EC-caused oxidative damage to the intestines and unveiled the remarkably protective benefits of M3A-induced AMPK-mediated autophagy against this toxicity.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antocianinas/farmacologia , Autofagia/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Uretana/farmacologia , Antocianinas/química , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Intestinos , Lisossomos/metabolismo , Simulação de Acoplamento Molecular , Fosforilação , Espécies Reativas de Oxigênio/metabolismo , Regulação para Cima , Uretana/química
17.
J Mech Behav Biomed Mater ; 110: 103951, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32957243

RESUMO

There is a great demand for the synthesis of acrylate based thermoset shape memory polymer (SMP) associated with one monomer and one crosslinker such as tert-butyl acrylate (t-BA) with poly (ethylene glycol) dimethacrylate (PEGDMA). The present work describes the synthesis of a new thermoset SMP wherein a second monomer such as diurethane dimethacrylate (DUDMA) has been added to the existing tBA + PEGDMA SMP matrix. The synthesized thermoset shape memory polymer exhibited a glass transition temperature (Tg) of 55 °C, higher Young's Modulus of 3.23 GPa, transmittance of 95% and 100% shape recovery. The SMP exhibited response to both thermal and chemical stimuli. The shape recovery rate of the SMP network is 20 s compared to 24 s observed for SMP based on tBA + PEGDMA. The obtained SMP is very transparent and possesses higher stiffness (8 MPa) and hence may be suitable for biomedical shape memory lens and orthopedic application.


Assuntos
Materiais Inteligentes , Acrilatos , Teste de Materiais , Metacrilatos , Polietilenoglicóis , Uretana/análogos & derivados
18.
Sheng Wu Gong Cheng Xue Bao ; 36(8): 1640-1649, 2020 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-32924362

RESUMO

Ethyl carbamate (EC) is a carcinogen detected in fermented foods and alcohol beverages. Excessive intake of EC is possibly harmful to health. Enzymatic degradation is one of the most effective approaches for reducing EC in fermented foods. Urease catalyzes the hydrolysis of both EC and urea. This confers urease a good application prospect in reducing EC and its precursor urea in fermented foods. Currently, degradation of EC in alcohol beverages by urease is inefficient due to its low urethanase activity and poor affinity to EC. Urease from Bacillus amyloliquefaciens JP-21 was successfully expressed in Escherichia coli at the level of 3 292 U/L urease and 227.3 U/L urethanase. Two key residues M326 and M374 were characterized that might block the binding of enzyme to EC, through simulating docking the structure of catalytic subunit UreC of urease with EC. Three mutants (M374A, M374T and M326V) of urease with improved urethanase activity were obtained by performing point saturated mutagenesis approach. Using EC as the substrate, Km values of M374A, M374T and M326V were detected to be 101.8 mmol/L, 129.5 mmol/L and 121.7 mmol/L, respectively, which were decreased by 37.47%-50.82% compared with that of the wild type urease. These mutants can degrade more than 97% of urea in rice wine and mutant M374T shows the highest degradation of EC in rice wine. EC content in rice wine was reduced from 525 µg/L to 393 µg/L by using M374T, and the EC degradation rate of it is 0.97 folds higher than that of the wild type urease. The results are of great significance for engineering the catalytic properties of urease and improving its industrial properties, and lays a good foundation for developing strategies to reducing microbial metabolic ammonia (amine) hazards in fermented foods.


Assuntos
Bacillus amyloliquefaciens , Microbiologia de Alimentos , Oryza , Urease , Uretana , Bacillus amyloliquefaciens/enzimologia , Bacillus amyloliquefaciens/genética , Carcinógenos/metabolismo , Mutagênese Sítio-Dirigida , Urease/genética , Urease/metabolismo , Uretana/metabolismo , Vinho/microbiologia
19.
Mikrochim Acta ; 187(9): 533, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32870401

RESUMO

A series of haptens were rationally designed for producing monoclonal antibodies specific for EC and a simple fluorescence immunoassay platform was developed for the sensitive determination of EC based on alkaline phosphatase (ALP)-triggered Cu+ quenching of CdSe quantum dots (QDs). It was noted that Cd as a fluorescence substrate in CdSe QDs can be selectively substituted by Cu+ that resulted in a more significant fluorescence quenching in comparison with Cu2+. Meanwhile, because ALP catalyzed ascorbic acid phosphate and then assisted the transformation of Cu2+ to Cu+, the change in fluorescence intensity was found to be proportional to ALP concentration. After simple magnetic separation, the sensitivity and linear range of the established assay were improved approximately 53-fold and an order of magnitude, respectively, when compared with the conventional ELISA. The proposed platform was able to both amplify the signal and eliminate matrix interferences, making it a promising to determine EC as well as other contaminants in complex food matrix in a highly sensitive and simple manner. Graphical abstract.


Assuntos
Carcinógenos/análise , Corantes Fluorescentes/química , Imunoensaio/métodos , Pontos Quânticos/química , Uretana/análise , Fosfatase Alcalina/química , Anticorpos Imobilizados/imunologia , Anticorpos Monoclonais/imunologia , Ácido Ascórbico/análogos & derivados , Compostos de Cádmio/química , Cobre/química , Fluorescência , Contaminação de Alimentos/análise , Separação Imunomagnética , Limite de Detecção , Microscopia de Fluorescência , Compostos de Selênio/química , Uretana/imunologia , Vinho/análise
20.
Anal Bioanal Chem ; 412(27): 7627-7637, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32897411

RESUMO

The aim of this work is to investigate the effect of the ethyl carbamate (EC) content in musalais on the metabolism of rats. Electron beam irradiation was performed to decrease the content of EC in musalais, and Sprague Dawley rats were subjected to intragastric administration of musalais with varying EC content (high, medium, and low groups). Control rats were fed normally without any treatment. Serum and urine samples were analyzed using ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry. Principal component analysis and orthogonal projections to latent structures discriminant analysis (OPLS-DA) were performed to detect changes in the metabolite profile in the serum and urine in order to identify the differential metabolites and metabolic pathways. The results demonstrated clear differences in the serum and urine metabolic patterns between control and treatment groups. Ions in treatment groups with variable importance in the projection of >1 (selected from the OPLS-DA loading plots) and Ps < 0.05 (Student t test) compared to control group were identified as candidate metabolites. Analysis of the metabolic pathways relevant to the identified differential metabolites revealed that high EC content in musalais (10 mg/kg) mainly affected rats through valine, leucine, and isoleucine biosynthesis and nicotinate and nicotinamide metabolism, which were associated with energy metabolism. In addition, this work suggests that EC can induce oxidative stress via inhibition of glycine content.


Assuntos
Metaboloma , Uretana/análise , Vinho/análise , Animais , China , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Redes e Vias Metabólicas , Metabolômica/métodos , Ratos , Ratos Sprague-Dawley , Soro/química , Soro/metabolismo , Uretana/administração & dosagem , Uretana/metabolismo , Urina/química
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