RESUMO
Ochratoxin A (OTA) is a mycotoxin contaminating agricultural products produced by fungi, associated with important toxic effects. Thus, the development of fast, sensitive, and economical approaches for OTA detection is crucial. In this study, a barcode-style lateral flow assay for the semi-quantitative detection of OTA in coffee samples was developed. To achieve this goal, a BSA-OTA complex was immobilized in three test zones to compete with OTA molecules in the sample for binding with anti-OTA antibodies labeled with gold nanoparticles. Different concentrations of OTA in the sample produced distinct colour patterns, allowing semi-quantification of the analyte. The assay exhibited high sensitivity, with a limit of detection of 2.5 µg.L-1, and high reproducibility, with variation coefficient values between 2% and 13%. Moreover, the colour patterns obtained in the analysis with coffee samples were similar to the results obtained with standard OTA solutions, demonstrating a reliable applicability in real samples.
Assuntos
Nanopartículas Metálicas , Ocratoxinas , Café/química , Ouro/química , Reprodutibilidade dos Testes , Contaminação de Alimentos/análise , Nanopartículas Metálicas/química , Ocratoxinas/análiseRESUMO
In this study, we developed a biosensor based on the localized surface plasmon resonance (LSPR) phenomenon of gold nanoparticles (AuNPs) to detect the widely used herbicide glyphosate in food samples. To do so, either cysteamine or a specific antibody for glyphosate were conjugated to the surface of the nanoparticles. AuNPs were synthesized using the sodium citrate reduction method and had their concentration determined via inductively plasma coupled mass spectrometry. Their optical properties were analyzed using UV-vis spectroscopy, X-ray diffraction, and transmission electron microscopy. Functionalized AuNPs were further characterized via Fourier-transform infrared spectroscopy, Raman scattering, Zeta potential, and dynamic light scattering. Both conjugates succeeded in detecting the presence of glyphosate in the colloid, although nanoparticles functionalized with cysteamine tended to aggregate at high concentrations of the herbicide. On the other hand, AuNPs functionalized with anti-glyphosate functioned at a broad concentration range and successfully identified the presence of the herbicide in non-organic coffee samples and when it was added to an organic coffee sample. This study demonstrates the potential of AuNP-based biosensors to detect glyphosate in food samples. The low-cost and specificity of these biosensors make them a viable alternative to current methods for detecting glyphosate in foodstuffs.
Assuntos
Nanopartículas Metálicas , Ressonância de Plasmônio de Superfície , Ressonância de Plasmônio de Superfície/métodos , Ouro/química , Café , Cisteamina , Nanopartículas Metálicas/químicaRESUMO
OBJECTIVES: To examine the prognostic significance of pretreatment C-reactive protein (CRP), N-terminal pro-brain natriuretic peptide (NT-proBNP), and cardiac troponin T (cTnT) levels on all-cause mortality 3 years after head and neck squamous cell carcinoma (HNSCC) diagnosis. SUBJECTS AND METHODS: Data from 118 consecutive HNSCC patients, treated between 2012 and 2015, were evaluated prospectively. The impact of CRP, high-sensitive (hs)-cTnT, and NT-proBNP levels on the 3-year overall survival was estimated using the Kaplan-Meier method and Cox proportional hazard models. RESULTS: During the 36-month follow-up, 37 patients (31.35%) died. Multivariate analysis revealed that elevated CRP (Hazard ratio: 3.71, 95% CI: 1.44-9.53, p = .007) and NT-proBNP levels (Hazard ratio: 5.04, 95% CI: 2.02-12.55, p = .001) were associated with negative prognosis, independent on age, sex, smoking and alcohol status, TNM classification, tumor site, body mass index (BMI), systolic blood pressure (SBP), and treatment modality (except for radiotherapy). hs-cTnT had no influence over the prognosis, but it was correlated with TNM classification and SBP. CRP was significantly correlated with BMI and TNM classification, and NT-proBNP with SBP and hs-cTnT. CONCLUSIONS: Pretreatment CRP and NT-proBNP levels were identified as independent prognostic markers for poor clinical outcome 3 years after HNSCC diagnosis.
Assuntos
Neoplasias de Cabeça e Pescoço , Fragmentos de Peptídeos , Troponina T , Biomarcadores , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Peptídeo Natriurético Encefálico , Prognóstico , Carcinoma de Células Escamosas de Cabeça e PescoçoRESUMO
PURPOSE: The effects of medium to long-term continuous positive airway pressure (CPAP) or physical activity in decreasing oxidative stress, inflammatory, and cell-free DNA markers in obstructive sleep apnea (OSA) have been explored. Here we evaluate oxidative stress markers (TBARS, AOPP, SOD), proinflammatory cytokines (TNF-α, IL-1ß, IL-6, IL-8), anti-inflammatory cytokines (IL-4, IL-10), and cell-free DNA levels before and after 8-week CPAP treatment or moderate-intensity aerobic training in moderate to severe OSA. METHODS: Thirty-nine patients diagnosed with OSA were randomly divided into CPAP (N = 18), with or without humidifier, and exercise groups (N = 21). Excessive daytime sleepiness and sleep quality were assessed by the Epworth Sleepiness Scale and the Pittsburgh questionnaire, respectively. Biomarkers for lipid and protein oxidation, pro and anti-inflammatory cytokines, and cell-free DNA were quantified in blood samples, before and after 8 weeks of both treatments. RESULTS: After 8 weeks of either CPAP or exercise, no significant differences were observed in the levels of cell-free DNA, oxidative stress, and inflammation markers, except for an increase in AOPP and IL-17A levels in individuals who went through CPAP, which were higher when the CPAP device was used without the humidifier. We have also observed that CPAP significantly decreased the Pittsburgh scores and improved sleep efficiency and hours of sleep, while ESS scores remained unaffected. CONCLUSIONS: Short-term treatment for OSA, be it CPAP therapy or moderate-intensity aerobic exercise, was not sufficient to alter either the oxidative stress and inflammatory profiles or the cell-free DNA levels of moderate to severe OSA patients. Short-term CPAP did, however, improve self-reported sleep quality.
Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Terapia por Exercício , Inflamação/sangue , Estresse Oxidativo/fisiologia , Apneia Obstrutiva do Sono/fisiopatologia , Apneia Obstrutiva do Sono/terapia , Adulto , Idoso , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
BACKGROUND: Mobility of fat deposited in adipocytes among different fatty territories can play a crucial role in the pathogenesis of obesity-related diseases. Our goal was to investigate which of the remaining fat pads assume the role of accumulating lipids after surgical removal of parietal WAT (lipectomy; LIPEC) in rats of both sexes displaying MSG-induced obesity. METHODS: The animals entered the study straight after birth, being separated according to gender and randomly divided into CON (control, saline-treated) and MSG (monosodium glutamate-treated) groups. Next, the animals underwent LIPEC or sham-operated surgery (SHAM). Obesity was induced by the injection of MSG (4 mg/g/day) during neonatal stage (2nd to 11th day from birth). LIPEC was performed on the 12th week, consisting in the withdrawal of parietal WAT. On the 16th week, the following WATs were isolated and collected: peri-epididymal-WAT (EP-WAT); parametrial-WAT (PM-WAT); omental-WAT (OM-WAT); perirenal-WAT (PR-WAT) and retroperitoneal-WAT (RP-WAT). RESULTS: The adiposity index was significantly increased in both male (3.2 ± 0.2** vs 1.8 ± 0.1) and female (4.9 ± 0.7* vs 2.6 ± 0.3) obese rats compared to their respective control groups. LIPEC in obese animals produced fat accumulation in visceral fat sites in a more accentuated manner in female (3.6 ± 0.3** vs 2.8 ± 0.3 g/100 g) rather than in male (1.8 ± 0.2* vs 1.5 ± 0.1 g/100 g) rats compared to obese non-lipectomized animals. Among the visceral WATs, the greater differences were observed between gonadal WATs of obese lipectomized rats, with higher accumulation having been observed in PM-WAT (2.8 ± 0.3* vs 2.1 ± 0.2 g/100 g) rather than in EP-WAT (1.0 ± 0.1 ± 0.9 ± 0.1 g/100 g) when compared to obese non-lipectomized animals. CONCLUSIONS: The results of the present study led us to conclude that obesity induced by MSG treatment occurs differently in male and female rats. When associated with parietal LIPEC, there was a significant increase in the deposition of visceral fat, which was significantly higher in obese female rats than in males, indicating that fat mobility among WATs in lipectomized-obese rats can occur more expressively in particular sites of remaining WATs.
Assuntos
Tecido Adiposo Branco/cirurgia , Tecido Adiposo/cirurgia , Lipectomia , Obesidade/cirurgia , Tecido Adiposo/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Masculino , Obesidade/metabolismo , Ratos , Ratos Wistar , Fatores SexuaisRESUMO
A number of neurotoxins from venoms of invertebrates and plants are ligands for voltage-gated Na+ channels and are useful tools for studying Na+ channel function and structure. Using whole-cell recordings from vagal afferent nodose neurons, we studied neurotoxins that target Na+ channels. We asked whether Ts3 (an alpha-scorpion toxin) and/or veratridine (a lipid-soluble toxin), could modify the TTX-resistant Na+ current generated by vagal afferent nodose neurons. Nodose TTX-resistant current was not affected by Ts3, whereas Ts3 slowed inactivation of the current generated by TTX-sensitive current component. We found that veratridine inhibited the TTX-resistant Na+ currents on rat nodose neurons. Interestingly, veratridine-modified Na+ channels developed a persistent current that accounted for the large tail current observed. We propose that veratridine modifies TTX-resistant Na+ channels through a mechanism distinct from its actions on other voltage-gated Na+ channels.