Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 78
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Exerc Immunol Rev ; 25: 50-62, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30785869

RESUMO

BACKGROUND: Aerobic training (AT) decreases airway inflammation in asthma, but the underlying cellular and molecular mechanisms are not completely understood. Thus, this study evaluated the participation of SOCS-JAK-STAT signaling in the effects of AT on airway inflammation, remodeling and hyperresponsiveness in a model of allergic airway inflammation. METHODS: C57Bl/6 mice were divided into Control (Co), Exercise (Ex), HDM (HDM), and HDM+Exercise (HDM+ Ex). Dermatophagoides pteronyssinus (100ug/mouse) were administered oro-tracheally on days 0, 7, 14, 21, 28, 35, 42 and 49. AT was performed in a treadmill during 4 weeks in moderate intensity, from day 24 until day 52. RESULTS: AT inhibited HDM-induced total cells (p<0.001), eosinophils (p<0.01), neutrophils (p<0.01) and lymphocytes (p<0.01) in BAL, and eosinophils (p<0.01), neutrophils (p<0.01) and lymphocytes (p<0.01) in peribronchial space. AT also reduced BAL levels of IL-4 (p<0.001), IL-5 (p<0.001), IL-13 (p<0.001), CXCL1 (p<0.01), IL-17 (p<0.01), IL-23 (p<0.05), IL-33 (p<0.05), while increased IL- 10 (p<0.05). Airway collagen fibers (p<0.01), elastic fibers p<0.01) and mucin (p<0.01) were also reduced by AT. AT also inhibited HDM-induced airway hyperresponsiveness (AHR) to methacholine 6,25mg/ml (p<0.01), 12,5mg/mL (p<0.01), 25mg/mL (p<0.01) and 50mg/mL (p<0.01). Mechanistically, AT reduced the expression of STAT6 (p<0.05), STAT3 (p<0.001), STAT5 (p<0.01) and JAK2 (p<0.001), similarly by peribronchial leukocytes and by airway epithelial cells. SOCS1 expression (p<0.001) was upregulated in leukocytes and in epithelial cells, SOCS2 (p<0.01) was upregulated in leukocytes and SOCS3 down-regulated in leukocytes (p<0.05) and in epithelial cells (p<0.001). CONCLUSIONS: AT reduces asthma phenotype involving SOCSJAK- STAT signaling.


Assuntos
Asma/metabolismo , Janus Quinases/metabolismo , Condicionamento Físico Animal , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Animais , Modelos Animais de Doenças , Eosinófilos/citologia , Interleucinas/metabolismo , Linfócitos/citologia , Cloreto de Metacolina , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/citologia , Hipersensibilidade Respiratória/metabolismo
2.
Int Endod J ; 51(1): 79-85, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28439909

RESUMO

AIM: To evaluate the alterations promoted by a thermally deposited siloxane-methacrylate coating on the surface of glass fibre posts and their effect on the bond strength of resin-core materials to the posts. METHODOLOGY: Fibre post surfaces were treated with experimental thermally deposited siloxane-methacrylate coatings or clinically available treatments (i.e. hydrogen peroxide and methylene chloride); nontreated posts were used as controls. The contact angles formed between the post surface and the water/adhesive were measured with a tensiometer. Scanning electron microscopy and electron dispersive spectroscopy were used to examine the topographies and chemical changes in the post surfaces following treatment. Surface roughness was evaluated with laser interferometry. Core resin was bonded to the fibre posts, and microtensile bond strength testing was subsequently performed. The data were individually submitted to anova and Tukey's tests (α = 0.05). RESULTS: The water contact angle was reduced significantly (P < 0.05) by the thermally deposited siloxane-methacrylate coating. All treatments significantly increased the adhesive contact angle (P ≤ 0.016) compared to the control as well as the surface roughness (P ≤ 0.006) and the amount of Si on post surfaces. Greater percentages of Si were observed for the thermally deposited coating. The bond strength to the posts was significantly improved by the thermally deposited coating (P < 0.05), whereas the other treatments did not differ from the control. CONCLUSION: Treating the surface of glass fibre posts with a thermally deposited siloxane-methacrylate coating improved the bond strength to resin-based materials. The coating could be performed by manufacturers of glass fibre posts in order to reduce the number of clinical steps required for luting posts into root canals.


Assuntos
Colagem Dentária , Vidro , Metacrilatos , Técnica para Retentor Intrarradicular , Siloxanas , Resistência à Tração , Humanos , Teste de Materiais
3.
Zygote ; 25(2): 111-119, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28264730

RESUMO

Previous investigations suggested that elevated cell-free DNA (cfDNA) can indicate non-healthy states. However, the potential association between cfDNA seminal plasma levels and fertility sperm parameters has not yet been determined. Therefore, the present study evaluated the association between seminal cfDNA levels and sperm fertility criteria to determine the use of seminal cfDNA quantification. An in vivo protocol quantified cfDNA levels of semen samples obtained from 163 male patients using fluorescent PicoGreen dye staining. To confirm if semen cfDNA quantification is realistic, an in vitro complementary test was performed using three or four semen samples. The fresh sperm samples were exposed to paraquat that generates high levels of superoxide anion causing oxidative stress and cell mortality. The results showed significant association between dsDNA levels and several sperm fertility parameters, such as low viability and alterations of motility and morphology. The in vitro analysis confirmed the association between dsDNA levels and sperm viability. Together, these results suggest that dsDNA levels could be an important biomarker to test sperm fertility.


Assuntos
DNA/análise , Corantes Fluorescentes/química , Infertilidade Masculina/fisiopatologia , Análise do Sêmen/métodos , Sêmen/química , Motilidade dos Espermatozoides , Adulto , Sistema Livre de Células , Humanos , Masculino , Compostos Orgânicos/química , Estresse Oxidativo
4.
Br Poult Sci ; 58(3): 224-229, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28277794

RESUMO

1. The performance of the scoring in the Danish footpad dermatitis (FPD) surveillance system was evaluated by determining inter-rater agreement in visual inspection of FPD in broilers between two independent raters (R1 and R2) and the official scoring at a Danish slaughterhouse. 2. FPD scores were evaluated in 1599 chicken feet. The two raters and the slaughterhouse scored equal proportions of score 0. So did R1 and R2 when assessing score 1 and the more severe lesion score 2, whereas the slaughterhouse scored a markedly higher proportion of score 1 and a lower proportion of score 2. Aggregated FPD flock scores ranged from 5 to 163 (R1 and R2) and from 8 to 107 (slaughterhouse). 3. The level of agreement between the two raters was high for scores 0, 1 and 2 and for flock scores. Agreement between raters and the slaughterhouse was lower when R1 and R2 recorded score 2 than when they recorded scores 0 and 1. 4. This study indicates that the occurrence and severity of lesions are underestimated in the official Danish FPD scoring system.


Assuntos
Criação de Animais Domésticos/métodos , Galinhas , Dermatite/veterinária , Monitoramento Epidemiológico/veterinária , Doenças do Pé/veterinária , Doenças das Aves Domésticas/patologia , Matadouros , Animais , Dinamarca , Dermatite/patologia , Doenças do Pé/patologia , Variações Dependentes do Observador
5.
Scand J Med Sci Sports ; 23(3): 317-22, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22092334

RESUMO

The purpose of this study was to assess the relationship between blood pressure (BP) levels and physical activity (PA) domains accounting for overweight/obesity. Adolescents aged 10 to 17 years old were recruited (n = 1021). International Obesity Task Force (IOTF) criteria were used to define overweight and obesity. High BP was defined using the Center of Disease Control and Prevention criteria. Different domains of PA (school activities, sport out of school, and leisure time PA) were assessed using a validated questionnaire. The prevalence of overweight/obesity was 21.9% for boys and 14.8% for girls. Some 13.4% of boys and 10.2% of girls, respectively, had high blood pressure (HBP). A strong and positive association was found between overweight and HBP. After adjustment for body mass index (BMI), total PA was inversely associated with BP. When all PA domains were entered simultaneously in a regression model, and after adjustment for BMI, only sport out of school was significantly and inversely associated with systolic BP [ß: -0.82 (-1.50; -0.13)]. These findings open avenue for the early prevention of HBP by the prevention of obesity and promotion of PA.


Assuntos
Hipertensão/epidemiologia , Atividade Motora/fisiologia , Obesidade/epidemiologia , Obesidade/fisiopatologia , Adolescente , Pressão Sanguínea , Índice de Massa Corporal , Brasil , Criança , Feminino , Humanos , Hipertensão/fisiopatologia , Masculino , Sobrepeso/epidemiologia , Sobrepeso/fisiopatologia , Prevalência , Esportes/fisiologia , Inquéritos e Questionários
6.
J Oral Rehabil ; 40(9): 686-92, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23829310

RESUMO

An extensive search for randomised controlled clinical trials was accomplished to compare dental prostheses and occlusal splints constructed with or without face-bow transfer, and question whether face-bow transfer may present better clinical results than simpler approaches. Studies were identified by searching electronic databases (PubMed/MEDLINE, Latin American and Caribbean Literature on the Health Science, and Brazilian Bibliography of Dentistry). The keywords 'dental articulator', 'semi-adjustable articulator', 'face-bow', 'jaw relation record' and 'occlusal splint therapy' were used. The minimum inclusion requirements were (i) randomised controlled trials with patients of any age, (ii) comparison between dental prostheses or occlusal splints constructed with or without face-bow transfer and (iii) assessment of clinician's time, number of occlusal contacts, patient satisfaction or masticatory function. The search resulted in the identification of 8779 articles. Subsequently, 8763 articles were excluded on the basis of title and abstract. By the end of the search phase, eight randomised controlled trials were considered eligible. Current scientific evidence suggests that face-bow transfer is not imperative to achieve better clinical results in prosthodontics. Randomised clinical trials suggest that simpler approaches for the construction of complete dentures and occlusal splints may present acceptable results, while no clinical study has investigated its use in fixed and removable partial dentures.


Assuntos
Prótese Dentária , Placas Oclusais , Prostodontia/métodos , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Prostodontia/instrumentação , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
7.
Oper Dent ; 46(3): 339-347, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34251455

RESUMO

This study aimed to characterize the surface topography, effect of polishing on surface roughness, residual stresses, and hardness in two glass-ceramic veneers. Fifty-two (52) upper incisors were collected, prepared, and scanned for ceramic veneers. Half of the teeth were restored with veneers made up of feldspathic ceramic (FE), and the other half with zirconia-reinforced lithium silicate ceramic (SZ). All the veneers were designed and milled using a CAD/CAM system and later cemented following the manufacturer's guideline. An optical microscope analyzed the topography of the specimens before and after polishing. The surface roughness was measured using the roughness meter (n=12) and the topographical analysis was carried out using an atomic force microscope (n=6). The residual stresses and Vickers' hardness were evaluated by the indentation method in a micro-hardness indenter (n=6). The surface roughness was analyzed using a three-way analysis of variance (ANOVA) followed by a post hoc Tukey test. The Student t-test was used to compare the residual stresses and hardness between the two ceramics. The topographical analysis revealed that both glass-ceramic veneers had similar percentages of specimens with cracks, before (34.6%) and after (42.3%) polishing. The surface roughness decreased after polishing (p<0.001), and the polishing smoothed out the surface of the veneers. The zirconia-reinforced lithium silicate veneer had a lower roughness as compared to the feldspathic one after polishing, while the residual stresses (p=0.722) and hardness (p=0.782) were statistically similar for both ceramic veneers.


Assuntos
Cerâmica , Porcelana Dentária , Desenho Assistido por Computador , Humanos , Teste de Materiais , Propriedades de Superfície
8.
AIDS Care ; 22(11): 1410-7, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20640951

RESUMO

Human immunodeficiency virus (HIV)-infected subjects have increased levels of oxidative stress which could impair immunological function and therefore contribute to the progression of AIDS. These characteristics are usually evaluated at rest and responses to exercise have yet to be evaluated. The aim of the present study was to assess the effect of a bout of aerobic exercise followed by resistance exercises on antioxidant system in HIV-infected and non-HIV subjects. There were included 14 cases (HIV-positive) and 14 controls (HIV-negative). The exercise protocol consisted of a single session of 20 minutes on a cycloergometer followed by a set of six resistance exercises. The activity of glutathione S-transferase (GST) and catalase were measured in plasma samples, total glutathione (TGSH) and thiobarbituric acid reactive substances (TBARS) were measured in erythrocytes. T CD4+ cells, T CD8+, viral load, complete blood count, and white blood count were also assessed. All measurements were performed at three times: baseline, after aerobic exercise, and after resistance exercises. At baseline, the HIV group had lower GST activity than controls, but after the exercise session GST values were similar in both groups. Compared to the control group TGSH was significantly lower in the HIV group at baseline, after aerobic and resistance exercises. The control group presented higher TBARS values after aerobic exercise compared to the HIV group. The neutrophil count was lower in the HIV group after aerobic and resistance exercises. These data indicate that HIV-infected subjects had lower antioxidant activity at rest. Physical exercise stimulated the enzymatic activity similarly in both groups.


Assuntos
Exercício Físico/fisiologia , Infecções por HIV/sangue , Estresse Oxidativo/fisiologia , Adulto , Antioxidantes/metabolismo , Estudos de Casos e Controles , Catalase/sangue , Eritrócitos/metabolismo , Teste de Esforço , Feminino , Glutationa/sangue , Glutationa Transferase/sangue , Infecções por HIV/enzimologia , Infecções por HIV/imunologia , Humanos , Peroxidação de Lipídeos/fisiologia , Masculino , Pessoa de Meia-Idade , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
9.
Cell Mol Biol (Noisy-le-grand) ; 56(2): 44-6, 2010 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-20525459

RESUMO

The aim of the present work is to propose a protocol for quantification of (18)F-FDG activities at organ level through whole body exams with Positron Emission Tomography. They were selected patients with normal uptake or a single tumor. In the period 2004-2005, 745 patients were studied. Among then, it was selected 97 adults for the normal uptake control group. The main studies were: intestine; colon, rectum, lung, lymphoma and melanoma, liver, esophagus, gonads and breasts. For "prospective screening", it were selected 20 patients with the identical physical characteristics of the control group. For internal dosimetry, the main organs should be elected according the kinetics of (18)F-FDG, either considering normal uptake or pathologies. Absorbed doses due to Computed Tomography and F-FDG uptake were estimated. Comparisons between internal and external exposures, for the same organ, point out higher doses due to external irradiation, except for bladder and kidneys. For individual dose estimation, parameters such the effective half-life should be known and this information may be achieved by an adaptation of the routine protocol.


Assuntos
Fluordesoxiglucose F18/análise , Imagem Multimodal/métodos , Tomografia por Emissão de Pósitrons/métodos , Radiometria/métodos , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Int J Clin Pract ; 64(6): 739-45, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20518949

RESUMO

OBJECTIVES: The aim of this was to compare the performance of the Framingham, Systematic Coronary Risk Evaluation (SCORE) and Prospective Cardiovascular Munster (PROCAM) scoring systems in the risk assessment of HIV-infected patients with no overt vascular disease. METHODS: A cross-sectional study of 220 HIV-infected patients was conducted at the outpatient clinic of a referral and training centre in infectious and parasitic diseases in Belo Horizonte, Brazil. The Framingham, SCORE and PROCAM equations were calculated. Patients were classified as having low, moderate or high risk, which according to the Framingham and PROCAM equations corresponded to < 10%, 10-20% and > 20% respectively, and according to SCORE corresponded to < 3%, 3-4% and > or = 5% respectively. Cohen's kappa coefficient was used to assess agreement between the methods. RESULTS: Of a total of 220 HIV-infected patients, 56 were antiretroviral (ARV)-naïve while 164 had already been treated with ARV. The prevalence of patients with a high 10-year cardiovascular risk was 3.7%, 2.5% and 1.9% according to the Framingham, PROCAM and SCORE equations respectively. The degree of agreement was moderate between the Framingham and PROCAM risk estimates (kappa = 0.433; p < 0.001), poor-to-fair between the Framingham and SCORE estimates (kappa = 0.220; p < 0.001) and moderate between the PROCAM and SCORE systems (kappa = 0.478; p < 0.001). CONCLUSIONS: There are differences in risk assessment and in the identification of high risk individuals between the three risk functions under evaluation and only a prospective study will be capable of assessing which offers the best current sensitivity, specificity and predictive values for the population under investigation.


Assuntos
Doença das Coronárias/virologia , Infecções por HIV/complicações , Adulto , Idoso , Fármacos Anti-HIV/uso terapêutico , Estudos Transversais , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco/métodos , Fatores de Risco , Adulto Jovem
11.
Neotrop Entomol ; 49(5): 745-757, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32445112

RESUMO

Interactions between different pest control methods can affect Integrated Pest Management efficiency. This study sought to evaluate (1) if Si accumulation is related to the level of constitutive resistance in sorghum genotypes, (2) the level of Si induces resistance by antibiosis in sorghum genotypes with different levels of constitutive resistance to Schizaphis graminum (Rondani) (reared individualized or in colonies), and (3) the fitness of Lysiphlebus testaceipes (Cresson) in aphids reared on Si-treated and untreated plants. Several experiments were conducted under greenhouse conditions, using sorghum genotypes with different levels of resistance grown in pots with or without the addition of Si to the soil. The susceptible (BR007B), moderately resistant (GB3B), and highly resistant (TX430XGR111) genotypes all absorbed more Si when it was added to the soil compared with when it was not amended. However, the final Si content of treated plants was not related to the level of constitutive resistance among treated genotypes. While Si soil application did reduce the fecundity of individualized aphids reared on the susceptible and moderately resistant sorghum plants, it did not reduce populational growth of aphid colonies, independent of the level of plant's constitutive resistance. Parasitoid (L. testaceipes) had higher weight when reared from aphids fed on plants with added Si. Sorghum × constitutive resistance × S. graminum interactions were affected by plant Si content only for individualized aphids but not for aphid colonies. Sorghum × S. graminum × L. testaceipes interactions suggest that Si can have, overall, a positive effect on the biological control of S. graminum.


Assuntos
Afídeos/crescimento & desenvolvimento , Controle Biológico de Vetores , Silício/administração & dosagem , Sorghum/genética , Vespas/fisiologia , Animais , Afídeos/parasitologia , Fertilizantes , Genótipo , Crescimento Demográfico , Solo/química
12.
Lung Cancer ; 139: 35-40, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31715539

RESUMO

OBJECTIVES: Mutations in the gene that encodes epidermal growth factor receptor (EGFR) are biomarkers that predict how non-small cell lung cancer (NSCLC) patients respond to EGFR-targeted therapies collectively known as tyrosine kinase inhibitors (TKIs). Thus, EGFR genotyping provides crucial information for treatment decision. Both Sanger sequencing and real-time PCR methodologies are used for EGFR genotyping. However, methods based on real-time PCR have limitations, as they may not detect rare or novel mutations. The aim of this study was to determine the prevalence of rare mutations in the tyrosine kinase domain (exons 18-21) of the EGFR gene not targeted by the most frequently used real-time PCR approaches, i.e., the cobas® EGFR Mutation Test, and the Idylla™ EGFR Mutation Assay. METHODS: A total of 1228 NSCLC patients were screened for mutations in exons 18-21 of the EGFR gene using Sanger sequencing. RESULTS: We observed that 252 patients (∼20%) had at least one mutation in the EGFR gene, and 38 (∼3%) carried uncommon genetic alterations that would not be identified by the cobas® or the Idylla™ tests. We further found six new single mutations and seven previously unreported compound mutations. Clinical information and patient outcome are presented for these cases. CONCLUSIONS: This study highlights the value of sequencing-based approaches to identify rare mutations. Our results add to the inventory of known EGFR mutations, thus contributing to improved lung cancer precision treatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Análise Mutacional de DNA/métodos , Tomada de Decisões , Neoplasias Pulmonares/genética , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Receptores ErbB/genética , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto Jovem
13.
Equine Vet J ; 51(4): 530-536, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30485499

RESUMO

BACKGROUND: Standing surgery avoids the risks of general anaesthesia in horses. OBJECTIVES: To assess sedation, antinociception and gastrointestinal motility in standing horses after a detomidine loading dose and 2-h constant rate intravenous (i.v.) infusion, with or without methadone. STUDY DESIGN: Blinded, randomised, crossover with seven healthy adult cross-bred horses, three geldings and four females (404 ± 22 kg). METHODS: Five i.v. treatments were administered to all horses with 1-week washout period: saline (SAL), detomidine low (2.5 µg/kg bwt + 6.25 µg/kg bwt/h) (DL) and high doses (5 µg/kg bwt + 12.5 µg/kg bwt/h) (DH) alone or combined with methadone (0.2 mg/kg bwt + 0.05 mg/kg bwt/h), (DLM) and (DHM), respectively. Height of head above the ground (HHAG), electrical (ET), thermal (TT) and mechanical (MT) nociceptive thresholds and gastrointestinal motility were evaluated at predetermined times between 5 and 240 min. A mixed effect model and Kruskal-Wallis test were used to analyse normally and non-normally distributed data, respectively. RESULTS: Sedation (<50% basal HHAG) was achieved for the duration of the infusion, and for an additional 15 min in DH and DHM groups. Nociceptive thresholds were higher than baseline, to the greatest degree and the longest duration, with DHM (ET and TT for 135 min and MT for 150 min). After DH, TT was significantly higher than baseline from 30 to 120 min and MT from 15 to 135 min. After DLM, ET was increased at 90 min, TT at 30 min and MT for 120 min. Gastrointestinal motility was reduced for up to 135 min after DL, 150 min after DLM and 210 min after DH and DHM. MAIN LIMITATIONS: Nociceptive thresholds are not equivalent to surgical stimuli. CONCLUSION: Methadone with the highest detomidine dose (DHM) may provide sufficient sedation and analgesia for standing surgical procedures and warrants further investigation.


Assuntos
Sedação Consciente/veterinária , Hipnóticos e Sedativos/farmacologia , Imidazóis/farmacologia , Metadona/farmacologia , Dor/veterinária , Animais , Quimioterapia Combinada , Feminino , Cavalos , Hipnóticos e Sedativos/administração & dosagem , Imidazóis/administração & dosagem , Masculino , Metadona/administração & dosagem , Dor/prevenção & controle , Distribuição Aleatória
14.
Neurosci Lett ; 446(2-3): 112-6, 2008 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-18835326

RESUMO

The involvement of dopamine (DA) mechanisms in the nucleus accumbens (NAC) in fear conditioning has been proposed by many studies that have challenged the view that the NAC is solely involved in the modulation of appetitive processes. However, the role of the core and shell subregions of the NAC in aversive conditioning remains unclear. The present study examined DA release in these NAC subregions using microdialysis during the expression of fear memory. Guide cannulae were implanted in rats in the NAC core and shell. Five days later, the animals received 10 footshocks (0.6 mA, 1 s duration) in a distinctive cage A (same context). On the next day, dialysis probes were inserted through the guide cannulae into the NAC core and shell subregions, and the animals were behaviorally tested for fear behavior either in the same context (cage A) or in a novel context (cage B). Dialysates were collected every 5 min for 90 min and analyzed by high-performance liquid chromatography. The rats exhibited a significant fear response in cage A but not in cage B. Moreover, increased DA levels in both NAC subregions were observed 5-25 min after the beginning of the test when the animals were tested in the same context compared with accumbal DA levels from rats tested in the different context. These findings suggest that DA mechanisms in both the NAC core and shell may play an important role in the expression of contextual fear memory.


Assuntos
Aprendizagem da Esquiva/fisiologia , Dopamina/metabolismo , Medo/fisiologia , Núcleo Accumbens/metabolismo , Animais , Condicionamento Psicológico/fisiologia , Estimulação Elétrica , Líquido Extracelular/metabolismo , Masculino , Microdiálise , Vias Neurais/fisiologia , Ratos , Ratos Wistar , Transmissão Sináptica/fisiologia
15.
Toxicon ; 51(8): 1467-78, 2008 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-18471841

RESUMO

Several nitrostyrene derivatives were synthesized and their inhibitive activities on phospholipase A(2) (PLA(2)) from Bothrops jararacussu venom were evaluated. Some compounds were very efficient as inhibition agents against edema-inducing, enzymatic and myotoxic activities. Data revealed that the size of the substitute and substitution position in the nitrostyrene moiety had important influence on the inhibition capacities. The enzymatic kinetic studies show that the nitrostyrene derivatives compounds inhibit PLA(2) in a non-competitive manner. The electronic, molecular and topologic parameters were calculated using ab initio quantum calculations (density functional theory-DFT) and analyzed by chemometric methods (principal component analysis (PCA) and hierarchical cluster analysis (HCA)) in order to build models able to establish relationships between the electronic features and the structure-activity presented by the target compound. Compounds with the nitro group in the ortho, meta and para position (compounds 2-4) on the aromatic ring were more efficient in the inhibition of PLA(2) activity in all tests. These results indicate that the influence of the nitro group in the aromatic ring is, in fact, important. In addition, quantum chemistry calculations show that compounds with a higher capacity of inhibiting PLA(2) present lower values of highest occupied molecular orbital (HOMO) energy and polarizability, suggesting the formation of a charge-transferring complex between the nitrostyrene compounds and PLA(2).


Assuntos
Bothrops , Venenos de Crotalídeos/química , Inibidores de Fosfolipase A2 , Estirenos/química , Animais , Análise por Conglomerados , Cinética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fosfolipases A2/isolamento & purificação , Estirenos/síntese química , Estirenos/farmacologia
16.
Environ Sci Process Impacts ; 20(9): 1210-1224, 2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30084851

RESUMO

This paper describes a methodology developed to assess and apportion probable indoor and outdoor sources of potentially toxic elements while identifying chemical signatures in the household dust collected from private homes in an industrial city (Estarreja, central Portugal). Oral bioaccessibility estimates and the chemical composition of toenail clippings were used to assess indoor dust ingestion as a potential exposure pathway and further investigate exposure-biomarker relationships. Indoor and paired outdoor dust samples were collected from each household. A total of 30 individuals, who provided toenail clippings and a self-reported questionnaire, were recruited for the study. Total concentrations of 34 elements, including lead and zinc, were determined in washed toenail samples and household dust via Inductively Coupled Plasma-Mass Spectrometry. The oral bioaccessibility was estimated using the Unified BARGE Method. The enrichment factor shows that lead was enriched (10 < EF < 100) while zinc (EF > 100) was anomalously enriched in the household dust, thus indicating potential exposure in the home environment. The results from principal component analysis coupled to cluster analysis and linear discriminant analysis suggested that mixed contamination derived from multiple sources with a predominance of biomass burning. Stepwise multiple linear regression analysis was performed to model toenail data using the indoor dust elemental composition. Whereas the model obtained for lead was not reliable, indoor dust zinc and antimony contents arose as good predictors of toenail zinc. The exposure-biomarker relationships seem to be influenced by the oral bioaccessibility of the elements.


Assuntos
Poeira/análise , Chumbo/análise , Unhas/química , Zinco/análise , Poluição do Ar em Ambientes Fechados/análise , Cidades , Exposição Ambiental/análise , Humanos , Portugal , Análise de Componente Principal , Análise de Regressão
17.
Braz J Med Biol Res ; 51(3): e6568, 2018 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-29340521

RESUMO

The goal of this study was to compare the visual contrast sensitivity (CS) of men and women exposed and not exposed to organic solvents. Forty-six volunteers of both genders aged between 18 and 41 years (mean±SD=27.72±6.28) participated. Gas station attendants were exposed to gas containing 46.30 ppm of solvents at a temperature of 304±274.39 K, humidity of 62.25±7.59% and ventilation of 0.69±0.46 m/s (a passive gas chromatography-based sampling method was used considering the microclimate variables). Visual CS was measured via the psychophysical method of two-alternative forced choice using vertical sinusoidal gratings with spatial frequencies of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0, and 16.0 cpd (cycles per degree) and an average luminance of 34.4 cd/m2. The results showed that visual CS was significantly lower (P<0.05) in the following groups: i) exposed men compared to unexposed men at frequencies of 0.2, 0.5, 1.0, and 2.0 cpd; ii) exposed women compared to unexposed women at a frequency of 5.0 cpd; and iii) exposed women compared to exposed men at a frequency of 0.5 cpd, even at exposures below the tolerance limit (300 ppm). These results suggest that the visual CS of exposed men was impaired over a wider range of spatial frequencies than that of exposed women. This difference may have been due to the higher body fat content of women compared to that of men, suggesting that body fat in women can serve as a protective factor against neurotoxic effects.


Assuntos
Sensibilidades de Contraste/efeitos dos fármacos , Exposição Ocupacional/efeitos adversos , Solventes/efeitos adversos , Percepção Visual/fisiologia , Tecido Adiposo/anatomia & histologia , Adolescente , Adulto , Brasil/epidemiologia , Escolaridade , Feminino , Humanos , Masculino , Microclima , Exposição Ocupacional/estatística & dados numéricos , Limiar Sensorial/fisiologia , Fatores Sexuais , Aprendizagem Espacial/fisiologia , Adulto Jovem
18.
J Sci Med Sport ; 10(3): 164-9, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16844409

RESUMO

The chronic and immediate post-exercise responses in the hemostatic and fibrinolytic systems have been shown to be variable and reflect differing adaptations with ageing and responses to exercise protocols. This study investigated the effects of acute and exhaustive exercise on the amplitude and duration of hemostatic and fibrinolytic responses in young adolescent males. The sample comprised 10 sedentary boys (13.2+/-0.5 years, 55.8+/-11.3kg, 165.7+/-7.4cm), who had not exercised or received any medication for at least 2 weeks before the experiments. The subjects performed exhaustive stepping exercise, consisting of 1s up and down cycles to fatigue. When the subjects were unable to maintain the required stepping rhythm, they were given a 30s recovery period. Following each 30s recovery participants recommenced the stepping cadence until fatigue prevented them continuing. Venous blood samples were drawn before and immediately, 1 and 24h after exercise to assess the following coagulation and fibrinolytic parameters: Platelet counts, activated partial thromboplastin time (aPTT), prothrombin time (PT), coagulation factor VIII (FVIII:C), von Willebrand factor (vWF), fibrinogen concentration, thrombin-antithrombin complex (TAT), D-dimer, plasminogen activator inhibitor (PAI-1), and tissue-type plasminogen activator (t-PA). Immediately following exercise, platelet counts, aPTT, FVIII, vWF and t-PA were significantly elevated in contrast to PAI-1, which decreased significantly until 1h after exercise. FVIII and platelet counts were elevated at 1 and 24h after exercise, respectively. Only the parameters FVIII and PAI-1 did not return to baseline values during the first hour after physical exercise. When compared to adults the results revealed different rates and ranges of coagulation and fibrinolysis parameters being activated by exhaustive exercise in this group of adolescents.


Assuntos
Fatores de Coagulação Sanguínea/análise , Exercício Físico/fisiologia , Hemostasia/fisiologia , Fadiga Muscular/fisiologia , Adolescente , Análise de Variância , Testes de Coagulação Sanguínea , Plaquetas , Criança , Ensaio de Imunoadsorção Enzimática , Teste de Esforço , Fibrinogênio/fisiologia , Humanos , Masculino
19.
Poult Sci ; 96(7): 2018-2028, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28204752

RESUMO

Danish legislation prescribes surveillance of footpad dermatitis (FPD) at slaughter as an indicator of on-farm broiler welfare. The 3-point scale being used was originally developed in Sweden to score feet from conventional broilers, but the extent and causes of misclassifications have not been investigated, neither in conventional nor organic broilers. Hence, we investigated the performance of the official Danish FPD scoring system in conventional and organic broilers by assessing agreement between official scores from the slaughterhouse and consecutive scoring of the same feet by a reference method. We also investigated the impact of performing an incision of the footpad during scoring. In total, 902 conventional and 897 organic broiler feet (∼100 per flock from 18 flocks) were collected at a large Danish slaughterhouse for the official FPD surveillance system. Laboratory scoring, according to predefined criteria for visual and invasive investigations of the feet derived from the official system, was compared to the official scores assigned at slaughter. Footpad lesions were primarily chronic, representing a wide range of severity. Marked differences in color, shape, and degree of papillary hypertrophy and hyperkeratosis of organic and conventional feet were observed. Low agreement primarily regarding score 2 lesions was observed when comparing official and reference foot scores in conventional (0.31) and organic (0.05) broilers. Variation in agreement when comparing flock scores suggested a non-systematic bias, which might be attributed to differences among official raters. The very low agreement in feet from organic broilers shows that these were more difficult to score than conventional. This might be due to a mismatch between lesion characteristics and scoring criteria, or because the lesions were less severe. Strictly visual examination detected 3 out of 4 score 2 lesions identified by the reference method. This study indicated that a large proportion of severe FPD lesions go unnoticed in the official Danish scoring system. The results further suggested that the complexity and impracticality of the scoring criteria impede uniform scoring among raters and production systems.


Assuntos
Galinhas , Dermatite/veterinária , Monitoramento Epidemiológico/veterinária , Doenças do Pé/veterinária , Vigilância da População/métodos , Doenças das Aves Domésticas/epidemiologia , Animais , Dermatite/epidemiologia , Dermatite/etiologia , Feminino , Doenças do Pé/epidemiologia , Doenças do Pé/etiologia , Masculino , Doenças das Aves Domésticas/etiologia , Prevalência , Suécia/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA