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1.
Nano Lett ; 21(23): 9853-9861, 2021 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-34807626

RESUMO

Animal testing is often criticized due to ethical issues and complicated translation of the results obtained to the clinical stage of drug development. Existing alternative models for nanopharmaceutical testing still have many limitations and do not significantly decrease the number of animals used. We propose a simple, bioinspired in vitro model for nanopharmaceutical drug testing based on the decellularized spinach leaf's vasculature. This system is similar to human arterioles and capillaries in terms of diameter (300-10 µm) and branching. The model has proven its suitability to access the maneuverability of magnetic nanoparticles, particularly those composed of Fe3O4. Moreover, the thrombosis has been recreated in the model's vasculature. We have tested and compared the effects of both a single-chain urokinase plasminogen activator (scuPA) and a magnetically controlled nanocomposite prepared by heparin-mediated cross-linking of scuPA with Fe3O4 nanoparticles. Compositions were tested both in static and flow conditions.


Assuntos
Pesquisa Biomédica/métodos , Nanomedicina , Spinacia oleracea , Animais , Encéfalo/metabolismo , Humanos , Folhas de Planta/metabolismo , Spinacia oleracea/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/farmacologia
2.
Int J Mol Sci ; 22(10)2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067696

RESUMO

Nanomaterials are proven to affect the biological activity of mammalian and microbial cells profoundly. Despite this fact, only surface chemistry, charge, and area are often linked to these phenomena. Moreover, most attention in this field is directed exclusively at nanomaterial cytotoxicity. At the same time, there is a large body of studies showing the influence of nanomaterials on cellular metabolism, proliferation, differentiation, reprogramming, gene transfer, and many other processes. Furthermore, it has been revealed that in all these cases, the shape of the nanomaterial plays a crucial role. In this paper, the mechanisms of nanomaterials shape control, approaches toward its synthesis, and the influence of nanomaterial shape on various biological activities of mammalian and microbial cells, such as proliferation, differentiation, and metabolism, as well as the prospects of this emerging field, are reviewed.


Assuntos
Células/efeitos dos fármacos , Nanoestruturas/química , Tamanho da Partícula , Fenômenos Fisiológicos Celulares/efeitos dos fármacos , Fenômenos Físicos
3.
Cells ; 12(4)2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36831277

RESUMO

Organoids are microtissues that recapitulate the complex structural organization and functions of tissues and organs. Nanoparticles have several specific properties that must be considered when replacing animal models with in vitro studies, such as the formation of a protein corona, accumulation, ability to overcome tissue barriers, and different severities of toxic effects in different cell types. An increase in the number of articles on toxicology research using organoid models is related to an increase in publications on organoids in general but is not related to toxicology-based publications. We demonstrate how the quantitative assessment of toxic changes in the structure of organoids and the state of their cell collections provide more valuable results for toxicological research and provide examples of research methods. The impact of the tested materials on organoids and their differences are also discussed. In conclusion, we highlight the main challenges, the solution of which will allow researchers to approach the replacement of in vivo research with in vitro research: biobanking and standardization of the structural characterization of organoids, and the development of effective screening imaging techniques for 3D organoid cell organization.


Assuntos
Bancos de Espécimes Biológicos , Nanopartículas , Animais , Organoides , Modelos Animais
4.
Toxicology ; 462: 152952, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34543703

RESUMO

Nanotoxicological studies using existing models of normal cells and animals often encounter a paradox: retention of nanoparticles in intracellular compartments for a long time is not accompanied by any significant toxicological effects. Can we expect that the revealed changes will be not harmful after translation to practice, outside of a sterile laboratory and ideally healthy organisms? Age-associated and pathological processes can affect target organs, metabolism, and detoxification in the mononuclear phagocyte system organs and change biodistribution routes, thus making the use of nanomaterial not safe. The potential solution to this issue can be testing the toxic properties of nanoparticles in animal models with chronic diseases. However, current studies of nanotoxicity in animal models with a brain, cardiovascular system, liver, digestive tract, reproductive system, and skin diseases are unsystematic. Even though these studies demonstrate the emergence of new toxic effects that are not present in healthy animals. In this regard, we set the goal of this review as the formulation of the requirements for an animal model capable of assessing the potential toxicity of nanoparticles based on the nanosafety approach.


Assuntos
Modelos Animais de Doenças , Nanopartículas/toxicidade , Testes de Toxicidade/métodos , Animais , Humanos , Modelos Animais , Distribuição Tecidual , Toxicologia/métodos
5.
Nanotoxicology ; 15(2): 167-204, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33216662

RESUMO

The unique properties of magnetic iron oxide nanoparticles determined their widespread use in medical applications, the food industry, textile industry, which in turn led to environmental pollution. These factors determine the long-term nature of the effect of iron oxide nanoparticles on the body. However, studies in the field of chronic nanotoxicology of magnetic iron particles are insufficient and scattered. Studies show that toxicity may be increased depending on oral and inhalation routes of administration rather than injection. The sensory nerve pathway can produce a number of specific effects not seen with other routes of administration. Organ systems showing potential toxic effects when injected with iron oxide nanoparticles include the nervous system, heart and lungs, the thyroid gland, and organs of the mononuclear phagocytic system (MPS). A special place is occupied by the reproductive system and the effect of nanoparticles on the health of the first and second generations of individuals exposed to the toxic effects of iron oxide nanoparticles. This knowledge should be taken into account for subsequent studies of the toxicity of iron oxide nanoparticles. Particular attention should be paid to tests conducted on animals with pathologies representing human chronic socially significant diseases. This part of preclinical studies is almost in its infancy but of great importance for further medical translation on nanomaterials to practice.


Assuntos
Compostos Férricos/toxicidade , Fenômenos Magnéticos , Nanopartículas/toxicidade , Animais , Engenharia Biomédica , Células Cultivadas , Compostos Férricos/química , Humanos , Nanopartículas/química , Especificidade de Órgãos , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Propriedades de Superfície , Testes de Toxicidade , Transcriptoma/efeitos dos fármacos
6.
J Mater Chem B ; 9(24): 4941-4955, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34105581

RESUMO

Thrombosis-related diseases are undoubtedly the deadliest disorders. During the last decades, numerous attempts were made to reduce the overall death rate and severe complications caused by treatment delays. Significant progress has been made in the development of nanostructured thrombolytics, especially magnetically controlled. The emergence of thrombolytic magnetic actuators, which can deliver tPA to the occlusion zone and perform mechanical disruption of the fibrin network under the application of a rotating magnetic field (RMF), can be considered for the next generation of thrombolytic drugs. Thus, we propose a systematic study of magnetic-field mediated mechanically-assisted thrombolysis (MFMMAT) for the first time. Four types of magnetic particles with different morphology and dimensionality were utilized to assess their impact on model clot lysis under different RMF parameters. Chain-like 1D and sea urchins-like 3D structures were found to be the most effective, increasing thrombolysis efficacy to nearly 200%. The drastic difference was also observed during the dissolution of 3 days old blood clots. Pure plasminogen activator had almost no effect on clot structure during 30 minutes of treatment while applying MFMMAT led to the significant decrease of clot area, thus uncovering the possibility of deep venous thrombosis therapy.


Assuntos
Fibrinolíticos/farmacologia , Campos Magnéticos , Anisotropia
7.
Pharmaceutics ; 12(11)2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33167402

RESUMO

Atherosclerosis, being an inflammation-associated disease, represents a considerable healthcare problem. Its origin remains poorly understood, and at the same time, it is associated with extensive morbidity and mortality worldwide due to myocardial infarctions and strokes. Unfortunately, drugs are unable to effectively prevent plaque formation. Systemic administration of pharmaceuticals for the inhibition of plaque destabilization bears the risk of adverse effects. At present, nanoscience and, in particular, nanomedicine has made significant progress in both imaging and treatment of atherosclerosis. In this review, we focus on recent advances in this area, discussing subjects such as nanocarriers-based drug targeting principles, approaches towards the treatment of atherosclerosis, utilization of theranostic agents, and future prospects of nanoformulated therapeutics against atherosclerosis and inflammatory diseases. The focus is placed on articles published since 2015 with additional attention to research completed in 2019-2020.

8.
Nanomaterials (Basel) ; 10(6)2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32471021

RESUMO

An investigation of the interaction principles of nucleic acids and nanoparticles is a priority for the development of theoretical and methodological approaches to creating bionanocomposite structures, which determines the area and boundaries of biomedical use of developed nanoscale devices. «Nucleic acid-magnetic nanoparticle¼ type constructs are being developed to carry out the highly efficient detection of pathogens, create express systems for genotyping and sequencing, and detect siRNA. However, the data available on the impact of nanoparticles on the behavior of siRNA are insufficient. In this work, using nanoparticles of two classical oxides of inorganic chemistry (magnetite (Fe3O4) and silica (SiO2) nanoparticles), and widely used gold nanoparticles, we show their effect on the rate of siRNA hybridization. It has been determined that magnetite nanoparticles with a positive charge on the surface increase the rate of siRNA hybridization, while negatively charged magnetite and silica nanoparticles, or positively charged gold nanoparticles, do not affect hybridization rates (HR).

9.
Nanomaterials (Basel) ; 9(11)2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31744137

RESUMO

Macrophages are components of the innate immune system that control a plethora of biological processes. Macrophages can be activated towards pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes depending on the cue; however, polarization may be altered in bacterial and viral infections, cancer, or autoimmune diseases. Metal (zinc, iron, titanium, copper, etc.) oxide nanoparticles are widely used in therapeutic applications as drugs, nanocarriers, and diagnostic tools. Macrophages can recognize and engulf nanoparticles, while the influence of macrophage-nanoparticle interaction on cell polarization remains unclear. In this review, we summarize the molecular mechanisms that drive macrophage activation phenotypes and functions upon interaction with nanoparticles in an inflammatory microenvironment. The manifold effects of metal oxide nanoparticles on macrophages depend on the type of metal and the route of synthesis. While largely considered as drug transporters, metal oxide nanoparticles nevertheless have an immunotherapeutic potential, as they can evoke pro- or anti-inflammatory effects on macrophages and become essential for macrophage profiling in cancer, wound healing, infections, and autoimmunity.

10.
Sci Rep ; 9(1): 1176, 2019 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-30718643

RESUMO

Alumina is one of the most promising carriers for drug delivery due to the long history of its usage as a vaccine adjuvant. Sol-gel synthesis provides excellent conditions for entrapment of biomolecules within an inorganic cage providing stabilization of proteins under the extremal conditions. In this paper, we show in vitro investigation of monodisperse alumina xerogel nanocontainers (AXNCs) using bovine serum albumin as a model protein entrapped in sol-gel alumina building blocks. Particularly, dose and cell-type dependent cytotoxicity in HeLa and A549 cancer cell lines were employed as well as investigation of antibacterial effect and stability of AXNCs in different biological media. It was shown, that the release of entrapped protein could be provided only in low pH buffer (as in cancer cell cytoplasm). This property could be applied for anticancer drug development. We also discovered boehmite nanoparticles effect on horizontal gene transfer and observed the appearance of antibiotic resistance by means of exchanging of the corresponding plasmid between two different E. coli strains. The present work may help to understand better the influence of AXNCs on various biological systems, such as prokaryotic and eukaryotic cells, and the activity of AXNCs in different biological media.


Assuntos
Hidróxido de Alumínio/síntese química , Óxido de Alumínio/síntese química , Portadores de Fármacos/síntese química , Nanopartículas Metálicas , Transição de Fase , Células A549 , Antibacterianos/metabolismo , Antineoplásicos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Ligação Proteica , Proteínas/metabolismo
11.
ACS Appl Mater Interfaces ; 10(36): 30040-30044, 2018 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-30137958

RESUMO

Nanocontainers based solely on magnetite NPs have been synthesized by indirect gelation of stable magnetite hydrosol at ambient temperature using the microemulsion-assisted sol-gel method. Containers synthesized have adjustable size and consist of ∼10 nm magnetite nanoparticles linked by Fe-O-Fe interparticle bonds. The material demonstrates high magnetization values up to 60 emu/g and low cytotoxicity against both HeLa and postnatal human fibroblast (up to 260 µg/mL). The systems developed are perspective as a drug depot, particularly for magnetically controlled thrombolysis.


Assuntos
Sistemas de Liberação de Medicamentos , Óxido Ferroso-Férrico/química , Nanopartículas de Magnetita/química , Células Cultivadas , Fibroblastos/metabolismo , Células HeLa , Humanos , Magnetismo , Tamanho da Partícula
12.
ACS Appl Mater Interfaces ; 10(43): 36764-36775, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30299938

RESUMO

Mortality and disabilities as outcomes of cardiovascular diseases are primarily related to blood clotting. Optimization of thrombolytic drugs is aimed at the prevention of side effects (in particular, bleeding) associated with a disbalance between coagulation and anticoagulation caused by systemically administered agents. Minimally invasive and efficient approaches to deliver the thrombolytic agent to the site of clot formation are needed. Herein, we report a novel nanocomposite prepared by heparin-mediated cross-linking of urokinase with magnetite nanoparticles (MNPs@uPA). We showed that heparin within the composition evoked no inhibitory effects on urokinase activity. Importantly, the magneto-control further increased the thrombolytic efficacy of the composition. Using our nanocomposition, we demonstrated efficient lysis of experimental clots in vitro and in animal vessels followed by complete restoration of blood flow. No sustained toxicity or hemorrhagic complications were registered in rats and rabbits after single bolus i.v. injection of therapeutic doses of MNPs@uPA. We conclude that MNPs@uPA is a prototype of easy-to-prepare, inexpensive, biocompatible, and noninvasive thrombolytic nanomedicines potentially useful in the treatment of blood clotting.


Assuntos
Sistemas de Liberação de Medicamentos , Óxido Ferroso-Férrico/química , Nanocompostos/química , Terapia Trombolítica/métodos , Ativador de Plasminogênio Tipo Uroquinase/química , Animais , Artérias Carótidas/patologia , Reagentes de Ligações Cruzadas/química , Desenho de Fármacos , Artéria Femoral/metabolismo , Fibrina/química , Fibrinolíticos/administração & dosagem , Humanos , Nanopartículas de Magnetita/uso terapêutico , Coelhos , Ratos , Eletricidade Estática , Distribuição Tecidual , Difração de Raios X
13.
Biotechnol Biofuels ; 10: 50, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28293288

RESUMO

BACKGROUND: Ethanol production from lignocellulosic feedstocks (also known as 2nd generation or 2G ethanol process) presents a great potential for reducing both ethanol production costs and climate change impacts since agricultural residues and dedicated energy crops are used as feedstock. This study aimed at the quantification of the economic and environmental impacts considering the current and future scenarios of sugarcane biorefineries taking into account not only the improvements of the industrial process but also of biomass production systems. Technology assumptions and scenarios setup were supported by main companies and stakeholders, involved in the lignocellulosic ethanol production chain from Brazil and abroad. For instance, scenarios considered higher efficiencies and lower residence times for pretreatment, enzymatic hydrolysis, and fermentation (including pentoses fermentation); higher sugarcane yields; and introduction of energy cane (a high fiber variety of cane). RESULTS: Ethanol production costs were estimated for different time horizons. In the short term, 2G ethanol presents higher costs compared to 1st generation (1G) ethanol. However, in the long term, 2G ethanol is more competitive, presenting remarkable lower production cost than 1G ethanol, even considering some uncertainties regarding technology and market aspects. In addition, environmental assessment showed that both 1G (in the medium and long term) and 2G ethanol can reduce climate change impacts by more than 80% when compared to gasoline. CONCLUSIONS: This work showed the great potential of 2G ethanol production in terms of economic and environmental aspects. These results can support new research programs and public policies designed to stimulate both production and consumption of 2G ethanol in Brazil, accelerating the path along the learning curve. Some examples of mechanisms include: incentives to the establishment of local equipment and enzyme suppliers; and specific funding programs for the development and use of energy cane.

14.
Sci Rep ; 6: 33037, 2016 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-27611846

RESUMO

Escherichia coli is an important experimental, medical and industrial cell factory for recombinant protein production. The inducible lac promoter is one of the most commonly used promoters for heterologous protein expression in E. coli. Isopropyl-ß-D-thiogalactoside (IPTG) is currently the most efficient molecular inducer for regulating this promoter's transcriptional activity. However, limitations have been observed in large-scale and microplate production, including toxicity, cost and culture monitoring. Here, we report the novel SILEX (Self-InducibLe Expression) system, which is a convenient, cost-effective alternative that does not require cell density monitoring or IPTG induction. We demonstrate the broad utility of the presented self-inducible method for a panel of diverse proteins produced in large amounts. The SILEX system is compatible with all classical culture media and growth temperatures and allows protein expression modulation. Importantly, the SILEX system is proven to be efficient for protein expression screening on a microplate scale.


Assuntos
Escherichia coli , Expressão Gênica , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
15.
Toxicol Sci ; 151(1): 115-25, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26865664

RESUMO

A diagnostic test system was developed to determine the toxicity of nanomaterials to the saltwater microalga Dunaliella salina through evaluation of cell death and changes in the culture growth rate at various toxicant concentrations, providing LC50 and other toxicological metrics. The viability of cells was shown to decrease with decreasing chlorophyll absorption of red light by damaged cells. This correlation was confirmed by independent fluorescence microscopic measurements of live and dead cells in the population. Two standard colorless pollutants, hydrogen peroxide and formaldehyde, were used to validate the colorimetric method. The method's performance is exemplified with three Ag-containing preparations (Ag nitrate, Ag proteinate, and 20-nm Ag nanoparticles) and with cetyltrimethylammonium bromide (CTAB) mixed with colloidal 15-nm Au and 20-nm Ag nanoparticles. The toxicity of the Ag-containing preparations to D. salina decreased in the order Ag nitrate ≥ Ag proteinate ≫ colloidal Ag. The toxicity of colloidal Au-CTAB mixtures was found to depend mostly on the content of free CTAB. The toxicity of colloidal Ag increased substantially in the presence of CTAB. The results suggest that our D. salina-based colorimetric test system can be used for simple and rapid preliminary screening of the toxicity of different nanomaterials.


Assuntos
Clorofila/metabolismo , Colorimetria , Ouro/toxicidade , Nanopartículas Metálicas/toxicidade , Microalgas/efeitos dos fármacos , Prata/toxicidade , Testes de Toxicidade/métodos , Biomarcadores/metabolismo , Coloides , Relação Dose-Resposta a Droga , Dose Letal Mediana , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Microscopia de Fluorescência
16.
FEBS Lett ; 379(2): 181-5, 1996 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-8635588

RESUMO

The effects of 3,3',5 triiodo-L-thyronine (L-T3) on the constitutive levels of hepatic mRNA encoding two UDP-glucuronosyltransferase (UGT) isoforms implicated in the glucuronidation of planar phenolic substrates (UGT1*06) and bilirubin (UGT1*0) were investigated in rat liver. The amount of UGT mRNA was quantitated by reverse transcription and amplification methods (RT-PCR). Treatment with L-T3 significantly increased UGT1*06 and decreased UGT1*0 mRNA levels by 41% and 54%, respectively. The opposite situation was observed in thyroidectomised animals. A good relationship observed between UGT activity toward 4-nitrophenol and bilirubin and mRNA levels emphasizes the key role played by the thyroid hormone L-T3 on UGT expression.


Assuntos
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glucuronosiltransferase/biossíntese , Fígado/enzimologia , Microssomos Hepáticos/enzimologia , Transcrição Gênica/efeitos dos fármacos , Tri-Iodotironina Reversa/farmacologia , Animais , Sequência de Bases , Primers do DNA , Glucuronosiltransferase/metabolismo , Cinética , Fígado/efeitos dos fármacos , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar
17.
Am J Clin Nutr ; 60(2): 255-61, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8030604

RESUMO

The effects of alcohol consumption on plasma concentrations of antioxidant vitamins (alpha-tocopherol and ascorbic acid), selenium, and markers of oxidative stress, especially malondialdehyde (MDA) and autoantibodies directed to MDA adducts to proteins (Ig-NH2-MDA) were investigated in a large population of 417 supposedly healthy men who consumed only low or moderate amounts of alcohol as compared with 102 alcoholic patients without severe liver disease, who were studied both before and after 21 d of withdrawal treatment. Plasma concentrations of alpha-tocopherol, ascorbic acid, and selenium were lower in alcoholics than in men who drank low amounts of alcohol (P < or = 0.001), whereas MDA and Ig-NH2-MDA were higher (P < or = 0.001). Plasma concentrations of alpha-tocopherol and selenium remained unchanged after the withdrawal period, whereas ascorbic acid (P < or = 0.01), MDA, and Ig-NH2-MDA concentrations decreased (P < or = 0.001). Adjustment of data for circulating lipids and nutritional intake suggests a specific effect of alcohol on antioxidant vitamins, independent of nutritional status.


Assuntos
Consumo de Bebidas Alcoólicas/sangue , Alcoolismo/sangue , Ácido Ascórbico/sangue , Estresse Fisiológico/etiologia , Vitamina E/sangue , Adulto , Alcoolismo/complicações , Ácido Ascórbico/administração & dosagem , Autoanticorpos/sangue , Ingestão de Alimentos , Ingestão de Energia , Glutationa Peroxidase/sangue , Humanos , Masculino , Malondialdeído/sangue , Oxirredução , Bases de Schiff/sangue , Selênio/sangue , Estresse Fisiológico/sangue , Superóxido Dismutase/sangue , Vitamina E/administração & dosagem
18.
Am J Clin Nutr ; 67(2): 231-9, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9459370

RESUMO

The aim of this study was to assess the association between smoking, food consumption, and antioxidant vitamin intake and plasma indexes of oxidative stress and antioxidant defenses in French adults. Food and nutrient intakes of 459 healthy men aged 23-57 y were estimated by the diet history method and analyzed by smoking status. Plasma alpha-tocopherol, ascorbic acid, and carotenoids were measured as antioxidants and malondialdehyde, protein Schiff bases, and autoantibodies against malondialdehyde-protein adducts as oxidative stress indexes. Smokers ate less fruit and vegetables than nonsmokers, leading to lower vitamin E, vitamin C, and carotene intakes, even after adjustment for age, education, and marital status. Unlike vitamin E, plasma ascorbic acid and beta-carotene concentrations were reduced in smokers compared with nonsmokers and were inversely related to cigarette consumption. This difference remained significant after adjustment for alcohol and dietary intakes. Among the measured oxidative stress indexes, only Schiff base concentration was positively related to the number of cigarettes smoked. In our sample of French men, smoking had an adverse effect on antioxidant status; vitamin intakes were reduced in smokers and plasma antioxidant indexes were altered independently of dietary intakes. As in other countries, in France smokers require particular attention in terms of public health intervention.


Assuntos
Antioxidantes/metabolismo , Dieta , Estresse Oxidativo , Fumar/metabolismo , Adulto , Antioxidantes/administração & dosagem , Ácido Ascórbico/sangue , Carotenoides/sangue , Colesterol/sangue , Inquéritos sobre Dietas , França , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Fumar/sangue , Fatores Socioeconômicos , Inquéritos e Questionários , Vitamina E/sangue , Vitaminas/administração & dosagem
19.
J Immunol Methods ; 128(2): 203-9, 1990 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-2324512

RESUMO

We describe a new double-antibody ELISA system using avidin-biotin amplication for the mass measurement of mitochondrial aspartate aminotransferase (m-AST) in human serum. The assay is very sensitive and as little as 0.5 ng/ml of m-AST may be detected. The method is linear up to 100 micrograms/l. The within-day and day-to-day coefficients of variation were found to be 8.9% and 11.5% respectively for a low m-AST concentration (2.7 micrograms/l), and 5.9% and 8.0% respectively for a high level of m-AST (30 micrograms/l). The assay requires 100 microliters of serum and can be completed within 5 h. The ELISA procedure and a classical immunoprecipitation technique measuring the catalytic activity of the isoenzyme were applied simultaneously to the sera of 189 subjects. The protein levels determined by ELISA correlated poorly (r = 0.66) with the catalytic activity of m-AST.


Assuntos
Aspartato Aminotransferases/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Mitocôndrias/enzimologia , Adolescente , Especificidade de Anticorpos , Aspartato Aminotransferases/imunologia , Aspartato Aminotransferases/metabolismo , Avidina , Biotina , Catálise , Feminino , Humanos , Isoenzimas/sangue , Isoenzimas/metabolismo , Masculino , Testes de Precipitina , Reprodutibilidade dos Testes
20.
J Endocrinol ; 170(1): 197-206, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11431152

RESUMO

It was reported that thyroid hormones decreased Cu(2+)-induced low-density lipoprotein (LDL) oxidation in vitro. Here, we investigated free radical scavenging capacities of thyroid hormones (3,5,3'-tri-iodo-L-thyronine (T(3)), thyroxine (T(4)) and 3,3',5'-tri-iodo-L-thyronine (rT(3))) and structural analogues (L-thyronine (T(0)), 3,5,3'tri-iodothyroacetic acid (TA(3)) and 3,5,3',5'-tetra-iodothyroacetic acid (TA(4))), using three different models of free radical generation. T(0), T(3) and TA(3) slowed down production of conjugated diene and thiobarbituric acid-reactive substances during LDL oxidation by 2,2'-azobis-[2-amidinopropane] (water-soluble), whereas rT(3), T(4) and TA(4) had practically no effect. In this system, T(0) was the more active compound. Using a 1,1-diphenyl-2-picrylhydrazyl (lipid-soluble) test, all compounds also revealed free radical scavenging capacities, but rT(3), T(4) and TA(4) were more active than T(0), T(3) and TA(3). T(3) was able to scavenge superoxide anion and hydroxyl radicals generated in an aqueous phase by a xanthine-xanthine oxidase system, as measured by electron paramagnetic resonance spectroscopy. It may be concluded that: (1) thyroid hormones and analogues with a 4'-hydroxy diphenylether structure have free radical scavenging capacities, (2) this property is influenced by the number of iodines on the phenolic ring, and (3) thyroid hormone scavenging capacity should not be the only mechanism explaining their protective effect on Cu(2+)-induced LDL oxidation. The physiological significance of the findings is discussed.


Assuntos
Sequestradores de Radicais Livres/farmacologia , Lipoproteínas LDL/química , Hormônios Tireóideos/farmacologia , Análise de Variância , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Oxirredução , Tiobarbitúricos/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Tiroxina/farmacologia , Tri-Iodotironina/farmacologia , Tri-Iodotironina Reversa/farmacologia
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