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INTRODUCTION: The use of three-dimensional (3D) printed anatomic models is steadily increasing in research and as a tool for clinical decision-making. The mechanical properties of polymers and metamaterials were investigated to evaluate their application in mimicking the biomechanics of the aortic vessel wall. METHODOLOGY: Uniaxial tensile tests were performed to determine the elastic modulus, mechanical stress, and strain of 3D printed samples. We used a combination of materials, designed to mimic biological tissues' properties, the rigid VeroTM family, and the flexible Agilus30™. Metamaterials were designed by tessellating unit cells that were used as lattice-reinforcement to tune their mechanical properties. The lattice-reinforcements were based on two groups of patterns, mainly responding to the movement between links/threads (chain and knitted) or to deformation (origami and diamond crystal). The mechanical properties of the printed materials were compared with the characteristics of healthy and aneurysmal aortas. RESULTS: Uniaxial tensile tests showed that the use of a lattice-reinforcement increased rigidity and may increase the maximum stress generated. The pattern and material of the lattice-reinforcement may increase or reduce the strain at maximum stress, which is also affected by the base material used. Printed samples showed max stress ranging from 0.39 ± 0.01 MPa to 0.88 ± 0.02 MPa, and strain at max stress ranging from 70.44 ± 0.86% to 158.21 ± 8.99%. An example of an application was created by inserting a metamaterial designed as a lattice-reinforcement on a model of the aorta to simulate an abdominal aortic aneurysm. CONCLUSION: The maximum stresses obtained with the printed models were similar to those of aortic tissue reported in the literature, despite the fact that the models did not perfectly reproduce the biological tissue behavior.
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This study presents comprehensive insights into the microbiological profile across all concentrated chicken broth processing stages, utilizing a combination of amplicon sequencing based on metataxonomic and culturing techniques. Samples were systematically collected throughout the production chain, with each batch yielding 10 samples per day across eight different dates. These samples underwent thorough analysis, including 16S rRNA and ITS sequencing (n = 30), culture-dependent microbiological tests (n = 40), and physical-chemical characterization (n = 10). Culturing analysis revealed the absence of Listeria monocytogenes and Salmonella spp. at any stage of processing, counts of various microorganisms such as molds, yeasts, Enterobacteria, and others remained below detection limits. Notably, spore counts of selected bacterial groups were observed post-processing, indicating the persistence of certain species, including Bacillus cereus and Clostridium perfringens, albeit in low counts. Furthermore, the study identified a diverse array of bacterial and fungal species throughout the processing chain, with notable occurrence of spore-forming bacteria. The presence of spore-forming bacteria in the final product, despite thermal processing, suggests the need for enhanced strategies to mitigate their introduction and persistence in the processing premises. Thus, this study offers valuable insights into microbial dynamics and diversity through processing concentrated chicken broth.
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Bactérias , Galinhas , Microbiologia de Alimentos , Fungos , Galinhas/microbiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/crescimento & desenvolvimento , Animais , Manipulação de Alimentos/métodos , RNA Ribossômico 16S/genética , Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Meios de Cultura/químicaRESUMO
Despite the wide variety of native and exotic fruits in Brazil, there is limited understanding of their ability to support pathogens during storage. This study aimed to evaluate the behavior of Salmonella enterica and Listeria monocytogenes inoculated into the pulp of eight fruits native and exotic to Brazil: Jenipapo (Genipa americana L.), Umbu (Spondias tuberosa Arruda), Maná (Solanum sessiliflorum), Cajá-manga (Spondias dulcis), Physalis (Physalis angulata L.), Feijoa (Acca sellowiana), Cupuaçu (Theobroma grandiflorum) (average pH < 3.3) and in a low acidy fruit: Abiu (Pouteria caimito) (pH 6.11). The pathogens were inoculated into the different fruits and stored at 10, 20, 30 and 37 °C for up to 12 h and 6 days, respectively. Among the fruits evaluated, Abiu was the only one that allowed Salmonella growth, showing higher δ-values at 20 and 30 °C (5.6 log CFU/g for both temperatures). For Physalis and Feijoa, there was a small reduction in the pathogen concentration (<1 log-cycle), mainly at 10 and 20 °C, indicating its ability to remain in the matrices. For the other fruits, notable negative δ-values were obtained, indicating a tendency towards microbial inactivation. The survival potential was significantly affected by temperature in Abiu, Maná, Cupuaçu, and Cajá-manga (p < 0.05). The same phenomena regarding δ-value were observed for L. monocytogenes population, with the greatest survival potential observed at 20 °C in Abiu (3.3 log CFU/g). Regarding the exponential growth rates in Abiu, the highest values were observed at 30 and 37 °C, both for Salmonella (4.6 and 4.9 log (CFU/g)/day, respectively) and for L. monocytogenes (2.8 and 2.7 log (CFU/g)/day, respectively), with no significant difference between both temperatures. Regarding microbial inactivation, L. monocytogenes showed greater resistance than Salmonella in practically all matrices. Jenipapo and Umbu were the pulps that, in general, had the greatest effect on reducing the population of pathogens. Furthermore, the increase in storage temperature seems to favor the increase on inactivation rates. In conclusion, Salmonella and L. monocytogenes can grow only in Abiu pulp, although they can survive in some acidic tropical fruits kept at refrigeration and abusive temperatures.
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Microbiologia de Alimentos , Frutas , Listeria monocytogenes , Salmonella enterica , Salmonella enterica/crescimento & desenvolvimento , Listeria monocytogenes/crescimento & desenvolvimento , Frutas/microbiologia , Brasil , Temperatura , Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Armazenamento de AlimentosRESUMO
The production of whole-liquid eggs is of significant economic and nutritional importance. This study aimed to assess the phenotypic and genotypic diversity of mesophilic aerobic spore-forming bacteria (nâ¯=â¯200) isolated from pasteurized whole liquid egg and liquid egg yolk. The majority of the isolates were identified as belonging to the genera Bacillus (86â¯%), followed by Brevibacillus (10â¯%) and Lysinibacillus (4â¯%). For the phenotypic characterization, isolates were subjected to various heat shocks, with the most significant reductions observed at 80⯰C/30â¯min and 90⯰C/10â¯min for isolates recovered from raw materials. On the other hand, the decrease was similar for isolates recovered from raw material and final product at 100⯰C/5 min and 110⯰C/5 min. Genotypic genes related to heat resistance (cdnL, spoVAD, dacB, clpC, dnaK, and yitF/Tn1546) were examined for genotypic characterization. The dnaK gene showed a positive correlation with the highest thermal condition tested (110⯰C/5 min), while 100⯰C/5 min had the highest number of positively correlated genes (clpC, cdnL, yitF/Tn1546, and spoVAD). Whole Genome Sequencing of four strains revealed genes related to sporulation, structure formation, initiation and regulation, stress response, and DNA repair in vegetative cells. The findings of this study indicate that these mesophilic aerobic spore-forming bacteria may adopt several strategies to persist through the process and reach the final product. As the inactivation of these microorganisms during egg processing is challenging, preventing raw materials contamination and their establishment in processing premises must be reinforced.
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Bacillus , Esporos Bacterianos , Esporos Bacterianos/genética , Bactérias , Cognição , Gema de OvoRESUMO
Fungi are the main microorganisms responsible for the spoilage of bakery products, and their control and subsequent reduction of food waste are significant concerns in the agri-food industry. Synthetic preservatives are still the most used compounds to reduce bakery product spoilage. On the other hand, studies have shown that biopreservation can be an attractive approach to overcoming food and feed spoilage and increasing their shelf-life. However, limited studies show the preservation effects on real food matrices. Therefore, this study aimed to investigate the influence of microorganisms such as lactic acid bacteria (LAB) and yeasts on the growth of spoilage filamentous fungi (molds) on bread and panettones. In general, on conventional and multigrain bread, treatments containing Limosilactobacillus fermentum IAL 4541 and Wickerhamomyces anomalus IAL 4533 showed similar results when compared to the negative control (calcium propionate) in delaying the fungal growth of the tested species (Aspergillus chevalieri, Aspergillus montevidensis, and Penicillium roqueforti). Different from bread, treatments with W. anomallus in panettones delayed the A. chevalieri growth up to 30 days, 13 days longer than observed on negative control (without preservatives). This study showed that biopreservation is a promising method that can extend bakery products' shelf-life and be used as an alternative to synthetic preservatives.
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Limosilactobacillus fermentum , Eliminação de Resíduos , Saccharomycetales , Alimentos , Fungos , Conservação de Alimentos/métodos , Microbiologia de Alimentos , Pão/microbiologiaRESUMO
This study aimed to determine Salmonella enterica occurrence along the soybean meal production chain (raw material, in-processing samples, final products, and in the environment of five processing plants), characterize the isolates, and assess the survival of Salmonella Senftenberg 775W in soybeans stored under different temperature conditions. Among 713 samples analyzed, 12.9% (n = 92) were positive for Salmonella enterica. Dust collected inside and outside processing plants (n = 148) comprised the samples with the highest positivity for Salmonella enterica, 47.3%. The occurrence of Salmonella enterica varied among the different processing plants. Twenty-nine (n = 29) Salmonella serotypes were isolated, with S. Mbandaka as the most frequent serotype, whereas S. Typhimurium was mainly linked to final product samples (soybean meal). S. Senftenberg 775W did not survive for a long time in soybean stored at 20-37 °C, but at 20 °C, cells were viable for more than 60 days. This study suggests that soybean meal may harbor Salmonella serotypes related to foodborne disease outbreaks in humans and can be responsible for Salmonella introduction into livestock and, consequently, in foods of animal origin. This study provides crucial data on contamination pathways of Salmonella in the soybean production chain, contributing to the understanding of Salmonella epidemiology which is strategic for the development of preventive and control measures to reduce the burden of salmonellosis linked to products of animal origin.
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Intoxicação Alimentar por Salmonella , Infecções por Salmonella , Salmonella enterica , Animais , Gado , Glycine maxRESUMO
Alkalization is a step of cocoa processing and consists of the use of alkali and high temperature to improve the sensorial and technological qualities of cocoa. Intense food processing can select spores, which can compromise safety and quality of the final product. Thus, the aim of this study was to evaluate the fate of B. cereus and G. stearothermophilus spores during the alkalization of pre-roasted (Pr) nibs (held at 120⯰C) and unroasted (Ur) nibs (held at 90⯰C) using potassium carbonate (0, 2, 4 and 6% w/w). In all conditions, log-linear inactivation kinetics with a tail was observed. The inactivation rate (kmax) for B. cereus varied from 0.065 to 1.67 min-1, whereas the kmax for G. stearothermophilus varied from 0.012 to 0.063 min-1. For both microorganisms, the lowest kmax values were observed during Ur nibs alkalization. The carbonate concentration increase promoted kmax values reduction. The highest tail values were observed for G. stearothermophilus in Ur nibs alkalization, reaching 3.04 log spores/g. Tail formation and low kmax values indicated that cocoa alkalization does not cause significant reductions on bacterial spore population. Therefore, the microbiological control should be primarily ensured by the raw material quality and by avoiding recontamination in the cocoa chain.
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Álcalis/química , Bacillus cereus/crescimento & desenvolvimento , Cacau/química , Cacau/microbiologia , Geobacillus stearothermophilus/crescimento & desenvolvimento , Viabilidade Microbiana/efeitos dos fármacos , Carbonatos/farmacologia , Manipulação de Alimentos , Microbiologia de Alimentos , Temperatura Alta , Potássio/farmacologia , Esporos BacterianosRESUMO
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
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[This corrects the article on p. 1113 in vol. 9, PMID: 29904375.].
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Aspergillus carbonarius and Aspergillus niger are the main responsible fungi for the accumulation of ochratoxin A (OTA) in wine grapes. Some strains are able to convert the parent mycotoxin into other compounds by means of hydrolysis and/or conjugation reactions through their defense mechanisms and enzymatic activity, leading to the formation of a modified mycotoxin. Thus, the variability of growth and metabolite production are inherent to the strain, occurring distinctively even when submitted to similar conditions. In this sense, this contribution aimed at determining the variability in multiplication and production of OTA by strains of A. carbonarius and A. niger isolated from grapes, as well as investigating the formation of modified mycotoxins. Strains were incubated in grape-based medium, and the diameter of the colonies measured daily. The determination of OTA was performed by high-performance liquid chromatography and the identification of modified mycotoxins was carried out using high-resolution mass spectrometry. Variabilities in terms of growth and OTA production were assessed across five different strains. Peak production of OTA was detected on day 15, and a decline on day 21 was observed, indicating that the observed reduction may be associated with the degradation or modification of the OTA over time by the fungus. Ethylamide ochratoxin A, a modified mycotoxin identified in this study, provides evidence that there may be underreporting of total mycotoxin levels in food, increasing uncertainty concerning health risks to the population.
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Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Meios de Cultura/química , Ocratoxinas/metabolismo , Aspergillus/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Técnicas Microbiológicas , Fatores de Tempo , Vitis/microbiologiaRESUMO
The variability in spore survival during spray drying of 12 Bacillus cereus strains was evaluated. B. cereus spores were inoculated on whole milk (7.2⯱â¯0.2â¯log10â¯spores/g dry weight) and processed in a spray-dryer. Twelve independent experiments were carried out in triplicate. The spore count was determined before and after each drying process, based on the dry weight of whole milk and powdered milk. Then, the number of decimal reductions (γ) caused by the spray drying process was calculated. B. cereus strains presented γ values ranging from 1.0 to 4.7â¯log10â¯spores/g dry weight, with a high coefficient of variation (CV) of 46.1%. Cluster analysis allowed to group B. cereus as sensitive (strains 511, 512, 540, 432 and ATCC 14579), intermediate (strains B18, B63, and B86) and resistant strains (strains B3, B94, B51 and 436). Three strains (one of each group) were selected for further investigation and characterization of their physicochemical and molecular (proteomics) differences. Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) were used to determine physicochemical characteristics and glass transition temperature (Tg), respectively. No differences in signs among the three strains were found in spectra ranging from 900 to 4000â¯cm-1. The endothermic peak ranged between 54 and 130⯰C for strain 540; between 81 and 163⯰C for strain B63; and between 110 and 171⯰C for strain 436. However, they showed different Tg: 88.82⯰C for strain 540; 114.32⯰C for strain B63; and 122.70⯰C for strain 436. A total of eleven spots were identified by mass spectrometry, with the spore coat protein GerQ, sporulation protein YtfJ (GerW), and peptidyl-prolyl cis-trans isomerase being found in at least two strains. Altogether, the results suggested that the high survival variability of B. cereus spores to the spray drying process seems to be mainly associated with different Tg and protein content. The study highlights the importance of quantifying the effects of this unit operation over the target microorganisms. These data may be relevant for the development of effective measures aiming to control the occurrence of B. cereus in milk powder as well as to reduce spoilage or safety issues associated with the presence of this bacterium in foods, particularly those formulated with milk powder.
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Bacillus cereus/crescimento & desenvolvimento , Doenças Transmitidas por Alimentos/prevenção & controle , Leite/microbiologia , Esporos Bacterianos/crescimento & desenvolvimento , Animais , Bacillus cereus/classificação , Varredura Diferencial de Calorimetria , Contagem de Colônia Microbiana , Dessecação , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Temperatura Alta , Peptidilprolil Isomerase/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , TemperaturaRESUMO
Spray drying is a widely used method for producing milk powder. This process is not aimed to cause microbial inactivation, thus sporeforming bacteria may be abundant in the microbiota of milk powder. The first aim of this study was to determine the inactivation kinetics parameters in capillary tubes of three Bacillus cereus strains (436, B63, 540) in three menstrua (whole milk, phosphate buffer, and talc suspension) at 90, 100, and 110°C. D-values for B. cereus in the three menstrua were not significantly different at the highest tested temperature (p > 0.05). Thus, talc was chosen as a carrier agent to allow the recovery of B. cereus from spray dried materials given its low interference on inactivation kinetics. B. cereus spores were also inoculated in whole milk and skim milk following spray drying at 95, 105, and 110°C (outlet temperature). After the spray drying runs, B. cereus spores were counted and the number of decimal reductions (γ) calculated. A correlation between the small diameter of the particles with the survival of spores of three B. cereus strains was found, and B. cereus 436 presented consistently the lowest γ no matter temperature and a carrier agent. The highest γ was found when talc powder was used, which suggest that this carrier agent does not protect B. cereus spores during spray drying. Spray drying of milk can lead to up to 4 γ (strain 540) of B. cereus spores but depending on the strain less than one γ (strain 436) could be observed. This study contributes to the knowledge on the microbiology of low water activity foods by providing novel findings regarding the fate of three B. cereus strains to different spray drying conditions. Acknowledging the variability of inactivation of B. cereus during spray drying is key in the current context of food safety in which the quantification of effects of unit operations must be known for the validation of processes and development of more robust formulations.
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OBJECTIVE: The objective was to determine risk factors associated with difficult venous access (DVA) in the emergency department (ED). METHODS: This was a prospective, observational study conducted in the ED of an urban tertiary care hospital. Adult patients undergoing intravenous (IV) placement were consecutively enrolled during periods of block enrollment. The primary outcome was DVA, defined as 3 or more IV attempts or use of a method of rescue vascular access to establish IV access. Univariate and multivariate analyses for factors predicting DVA were performed using logistic regression. RESULTS: A total of 743 patients were enrolled, of which 88 (11.8%) met the criteria for DVA. In the adjusted analysis, only 3 medical conditions were significantly associated with DVA: diabetes (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.1-2.8), sickle cell disease (OR 3.8, 95% CI 1.5-9.5), and history of IV drug abuse (OR 2.5, 95% CI 1.1-5.7). Notably, age, body mass index, and dialysis were not. Of patients who reported a history of requiring multiple IV attempts in the past for IV access, 14% met criteria for DVA on this visit (OR 7.7 95% CI 3-18). Of the patients who reported a history of IV insertion into the external jugular, ultrasound-guided IV placement, or a central venous catheter for IV access, 26% had DVA on this visit (OR 16.7, 95% CI 6.8-41). CONCLUSIONS: Nearly 1 of every 9 to 10 adults in an urban ED had DVA. Diabetes, IV drug abuse, and sickle cell disease were found to be significantly associated with DVA.
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Anemia Falciforme/epidemiologia , Cateterismo Venoso Central/estatística & dados numéricos , Cateterismo Periférico/estatística & dados numéricos , Diabetes Mellitus/epidemiologia , Hospitais Urbanos , Abuso de Substâncias por Via Intravenosa/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Índice de Massa Corporal , Estudos de Coortes , Serviço Hospitalar de Emergência , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Philadelphia/epidemiologia , Estudos Prospectivos , Diálise Renal/estatística & dados numéricos , Fatores de Risco , Centros de Atenção Terciária , Adulto JovemRESUMO
Neurofibromatosis type 1 (NF1) is a genetic disorder that predisposes patients to the formation of sporadic tumors and also increases the risk of radiation-induced malignancies. The most commonly described radiation-induced tumor in NF1 patients is a malignant peripheral nerve sheath tumor. We present 2 children with NF1 who received radiation therapy and subsequently developed high-grade gliomas. We then review the current literature on radiation-induced tumors in NF1 patients. Although radiation may be the most appropriate therapy in specific situations for children with NF1, the secondary tumor risk should be carefully considered.
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Neoplasias Encefálicas/etiologia , Glioma/etiologia , Neoplasias Induzidas por Radiação/patologia , Neurofibromatose 1/radioterapia , Criança , Pré-Escolar , Humanos , Neurofibromatose 1/patologiaAssuntos
Falso Aneurisma/diagnóstico , Traumatismos da Mão/complicações , Mãos/irrigação sanguínea , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/etiologia , Falso Aneurisma/patologia , Criança , Feminino , Mãos/diagnóstico por imagem , Mãos/patologia , Traumatismos da Mão/patologia , Humanos , UltrassonografiaRESUMO
Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. The results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.
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Proteína C-Reativa/metabolismo , Creatina Quinase Forma MM/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Exercício Físico/fisiologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Fragmento de Restrição/fisiologia , Polimorfismo de Nucleotídeo Único/fisiologia , Adolescente , Adulto , Atletas , Proteína C-Reativa/análise , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de Restrição/genética , Fatores de Risco , Adulto JovemRESUMO
Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. Results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.
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Proteína C-Reativa/genética , Creatina Quinase Forma MM/genética , Exercício Físico/fisiologia , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Esforço Físico/genética , Polimorfismo de Nucleotídeo Único/genética , Adolescente , Adulto , Creatina Quinase Forma MM/sangue , Feminino , Humanos , Masculino , Metilenotetra-Hidrofolato Desidrogenase (NADP)/sangue , Pessoa de Meia-Idade , Corrida/fisiologia , Adulto JovemRESUMO
OBJECTIVES: Reactive oxygen species account for the background levels of oxidatively damaged DNA in normal tissues. Physical exercise increases oxygen consumption and can cause oxidative stress. This stress can also involve deficient antioxidant defenses, which can be influenced by certain genetic polymorphisms. Because regular exercise is a known inducer of antioxidant enzymes, the objective of this study was to compare, by comet assay, differences in the DNA damage between apparently healthy individuals and trained aerobic sportsmen carrying the same single nucleotide polymorphisms of manganese superoxide dismutase (Val9Ala), catalase (-21A/T), glutathione peroxidase 1 (Pro198Leu), before and after exposing leukocytes from peripheral blood to hydrogen peroxide (H2O2). METHODS: Athletes were compared with nonathletes after a situation that promotes reactive oxygen species increase (a race). Blood samples were submitted to genotyping and comet assay, and the athletes and nonathletes were paired according to their gender, age, and MnSOD, CAT, and GPx-1 genotypes. RESULTS: For nonathletes, there was a positive correlation between H2O2 concentrations and DNA damage levels. For athletes, these correlations showed differences between sexes, indicating that running may impose higher oxidative stress on the DNA of women than of men. Significant differences appeared for nonathletes in the comparisons between younger and older age groups after treatment with H2O2 at 250 µM. CONCLUSIONS: This suggests that, for individuals carrying the same genotypes of antioxidant enzymes' genes, the effect of H2O2-induced oxidative stress depends mainly on age and physical training. It also suggests that aerobic physical training can reduce oxidative damages to DNA, preventing related diseases in older people.
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Exercício Físico/fisiologia , Peróxido de Hidrogênio/farmacologia , Leucócitos/metabolismo , Estresse Oxidativo , Aptidão Física/fisiologia , Adolescente , Adulto , Fatores Etários , Atletas , Catalase/genética , Dano ao DNA , Feminino , Genótipo , Glutationa Peroxidase/genética , Humanos , Leucócitos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fatores Sexuais , Superóxido Dismutase/genética , Glutationa Peroxidase GPX1RESUMO
BACKGROUND: Normal cellular metabolism is well established as the source of endogenous reactive oxygen species which account for the background levels of oxidative DNA damage detected in normal tissue. Hydrogen peroxide imposes an oxidative stress condition on cells that can result in DNA damage, leading to mutagenesis and cell death. Several potentially significant genetic variants related to oxidative stress have already been identified, and angiotensin I-converting enzyme (ACE) inhibitors have been reported as possible antioxidant agents that can reduce vascular oxidative stress in cardiovascular events. METHODS: We investigate the influences of haptoglobin, manganese superoxide dismutase (MnSOD Val9Ala), catalase (CAT -21A/T), glutathione peroxidase 1 (GPx-1 Pro198Leu), ACE (I/D) and gluthatione S-transferases GSTM1 and GSTT1 gene polymorphisms against DNA damage and oxidative stress. These were induced by exposing leukocytes from peripheral blood of healthy humans (N = 135) to hydrogen peroxide (H2O2), and the effects were tested by comet assay. Blood samples were submitted to genotyping and comet assay (before and after treatment with H2O2 at 250 microM and 1 mM). RESULTS: After treatment with H2O2 at 250 microM, the GPx-1 polymorphism significantly influenced results of comet assay and a possible association of the Pro/Leu genotype with higher DNA damage was found. The highest or lowest DNA damage also depended on interaction between GPX-1/ACE and Hp/GSTM1T1 polymorphisms when hydrogen peroxide treatment increased oxidative stress. CONCLUSIONS: The GPx-1 polymorphism and the interactions between GPX-1/ACE and Hp/GSTM1T1 can be determining factors for DNA oxidation provoked by hydrogen peroxide, and thus for higher susceptibility to or protection against oxidative stress suffered by healthy individuals.
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Ensaio Cometa , Dano ao DNA/genética , Peróxido de Hidrogênio/farmacologia , Leucócitos/efeitos dos fármacos , Polimorfismo Genético/efeitos dos fármacos , Adolescente , Adulto , Catalase/genética , Dano ao DNA/efeitos dos fármacos , Feminino , Genótipo , Glutationa Peroxidase/genética , Glutationa Transferase/genética , Haptoglobinas/genética , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Peptidil Dipeptidase A/genética , Polimorfismo Genético/genética , Superóxido Dismutase/genética , Adulto Jovem , Glutationa Peroxidase GPX1RESUMO
Physical training induces beneficial adaptation, whereas exhaustive exercises increase reactive oxygen-species generation, thereby causing oxidative damage in plasma and erythrocytes, fractions susceptible to lipid peroxidation. Pequi (Caryocar brasiliense Camb.) is a Brazilian Cerrado fruit containing a carotenoid-rich oil. The aim was to investigate the effects of pequi-oil on exercise-induced oxidative damage in plasma and erythrocytes, after running in the same environment and undergoing weekly training under the same conditions as to type, intensity and length. Evaluations were accomplished after outdoor running on flat land before and after ingestion of 400 mg pequi-oil capsules for 14 days. Blood samples were taken after running and submitted to TBARS assay and erythrogram analysis. Haptoglobin, MnSOD (Val9Ala), CAT (21A/T) and GPX1 (Pro198Leu) gene polymorphisms were priorly investigated, so as to estimate genetic influence The reduction in erythrocytes, hemoglobin and hematocrit after pequi-oil treatment was notably associated with higher plasma expansion. Except for MCHC (mean corpuscular hemoglobin concentration) and RDW (red cell distribution width), the results were influenced by the polymorphisms studied. The best response to pequi-oil was presented by MnSOD Val/Val, CAT AA or AT genotypes and the GPX1 Pro allele. The significantly lower RDW and higher MHCH values were related to pequi-oil protective effects. Pequi oil, besides possessing other nutritional properties, showed protective blood effects.