Evaluation of enlarged mediastinal lymph nodes is crucial for patient management. Malignant lymphoma and sarcoidosis are often difficult to differentiate. Our objective was to determine the ...diagnostic accuracy of MRI for differentiating between sarcoidosis and malignant lymphoma.
This was a retrospective study involving 47 patients who underwent chest MRI and were diagnosed with one of the diseases between 2017 and 2019. T1, T2, and diffusion-weighted signal intensity were measured. Apparent diffusion coefficients (ADCs) and T2 ratios were calculated. The diagnostic performance of MRI was determined by ROC analysis.
Mean T2 ratio was significantly lower in the sarcoidosis group than in the lymphoma group (p = 0.009). The T2-ratio cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 7.1, with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 58.3%, 95.6%, 76.5%, 93.3%, and 68.7%, respectively. The mean ADC was significantly lower in the lymphoma group than in the sarcoidosis group (p = 0.002). The ADC cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 1.205, with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 87.5%, 82.6%, 85.1%, 84.0% and 86.3%, respectively. No significant differences were found between the two groups regarding T1 signal intensity, T2 signal intensity, and lymph node diameter.
MRI parameters such as ADC, diffusion, and T2 ratio can be useful in the differentiation between sarcoidosis and lymphoma in the evaluation of enlarged lymph nodes.
After cardiac arrest, organ damage consequent to ischemia-reperfusion has been attributed to oxidative stress. Mild therapeutic hypothermia has been applied to reduce this damage, and it may reduce ...oxidative damage as well. This study aimed to compare oxidative damage and antioxidant defenses in patients treated with controlled normothermia versus mild therapeutic hypothermia during postcardiac arrest syndrome. The sample consisted of 31 patients under controlled normothermia (36°C) and 11 patients treated with 24 h mild therapeutic hypothermia (33°C), victims of in- or out-of-hospital cardiac arrest. Parameters were assessed at 6, 12, 36, and 72 h after cardiac arrest in the central venous blood samples. Hypothermic and normothermic patients had similar S100B levels, a biomarker of brain injury. Xanthine oxidase activity is similar between hypothermic and normothermic patients; however, it decreases posthypothermia treatment. Xanthine oxidase activity is positively correlated with lactate and S100B and inversely correlated with pH, calcium, and sodium levels. Hypothermia reduces malondialdehyde and protein carbonyl levels, markers of oxidative damage. Concomitantly, hypothermia increases the activity of erythrocyte antioxidant enzymes superoxide dismutase, glutathione peroxidase, and glutathione S-transferase while decreasing the activity of serum paraoxonase-1. These findings suggest that mild therapeutic hypothermia reduces oxidative damage and alters antioxidant defenses in postcardiac arrest patients.
Patients undergoing mechanical ventilation (MV) often experience respiratory muscle dysfunction, which complicates the weaning process. There is no simple means to predict or diagnose respiratory ...muscle dysfunction because diagnosis depends on measurements in muscle diaphragmatic fibre. As oxidative stress is a key mechanism contributing to MV‐induced respiratory muscle dysfunction, the aim of this study was to determine if differences in blood measures of oxidative stress in patients who had success and failure in a spontaneous breathing trial (SBT) could be used to predict the outcome of MV. This was a prospective analysis of MV‐dependent patients (≥72 hrs; n = 34) undergoing a standard weaning protocol. Clinical, laboratory and oxidative stress analyses were performed. Measurements were made on blood samples taken at three time‐points: immediately before the trial, 30 min. into the trial in weaning success (WS) patients, or immediately before return to MV in weaning failure (WF) patients, and 6 hrs after the trial. We found that blood measures of oxidative stress distinguished patients who would experience WF from patients who would experience WS. Before SBT, WF patients presented higher oxidative damage in lipids and higher antioxidant levels and decreased nitric oxide concentrations. The observed differences in measures between WF and WS patients persisted throughout and after the weaning trial. In conclusion, WF may be predicted based on higher malondialdehyde, higher vitamin C and lower nitric oxide concentration in plasma.
Reproduction alters the male physiology. We performed a comprehensive examination of oxidative stress in the kidneys of male rats with (experienced) or without (naïve) reproductive activity during ...aging. Oxidative stress was assessed by measuring the activity of catalase, glutathione peroxidase, glutathione S-transferase, and superoxide dismutase, and by measuring protein carbonylation, lipid peroxidation, nitrite and nitrate levels, vitamin C levels, and glutathione (total, reduced, and oxidized forms) levels, and metabolism was accessed by aconitase activity in kidney tissue, as well as testosterone and estradiol levels in serum. Reproductively active animals exhibited increased testosterone levels and altered metabolism. Aging affects tissues and organs and contributes to their functional decline. Elderly naïve rats showed high nitrite and nitrate levels. The experienced rats had less damage in elderly ages, probably because they had higher antioxidant amount and antioxidant enzyme activities at earlier ages, which would have avoided oxidative damage seen in naïve group, and because of the metabolism decline. Glutathione increase in naïve elder rats probably was induced for direct protection against oxidative damage and indirect protection by higher glutathione peroxidase and glutathione S-transferase activities. Linear regression shows that lipid peroxidation levels explained vitamin C levels (B standardized value of 0.42), indicating that vitamin C was properly produced or recruited into kidneys to combat lipid peroxidation. Catalase activity reflected the protein carbonylation and lipid peroxidation levels (B standardized values of 0.28 and 0.48). These results add comprehensive data regarding changes in oxidative stress during aging, and suggest an explanation for the costs of reproduction.
► Kidney aging is important in terms of public health and costs. ► Reproductive activity increases testosterone levels and metabolism. ► This increase alters antioxidant enzymes activities and levels. ► Oxidative damage is also observed by this increased metabolism. ► Basis for the so called “costs of reproduction” theory is suggested.
Abstract
Sleep disordered breathing (SDB) is related to coronary artery disease (CAD), but the mechanisms are uncertain. SDB is characterized by periods of intermittent hypoxia and free radical ...formation. This study tested the hypothesis that carbonylation can be the link between SDB and CAD. It included 14 cases with CAD and 33 controls with <50% coronary narrowing. CAD cases have higher erythrocyte carbonyl levels than controls (p = 0.012). Positive correlation was observed between apnea-hypopnea index (AHI) and erythrocyte carbonyl concentration (ρ = 0.310; p = 0.027). To predict CAD, including as regressors: AHI, erythrocyte carbonyl, gender, age and body mass index, the significant variables in the Poisson multiple regression model were AHI and erythrocytes carbonyl. An increase of 1 pmol/gHb in erythrocyte carbonyl levels increases by 1.8% the risk of CAD and one unit of AHI increases by 3.8% the risk of CAD. The present findings represent the first evidence in humans that SDB may cause CAD through protein carbonylation.
Elevated ferritin levels may lead to oxidative stress, and are associated with coronary artery disease (CAD). Sleep disordered breathing (SDB) is frequently present in atherosclerosis patients, and ...causes endothelial dysfunction leading to atherosclerotic plaque progression. Hypoxic conditions, such as SDB, may upregulate ferritin. The aim of this study was to evaluate ferritin levels in CAD patients and to correlate ferritin levels with parameters related to CAD progression, including SDB. We studied 27 patients with CAD (defined as >30% coronary narrowing) and 29 controls. We found that ferritin was increased in CAD patients, and was positively correlated with the apnea–hypopnea index (AHI), age, C-reactive protein (CRP), transferrin, hemoglobin, and testosterone levels, and was negatively correlated with O2 saturation. Nitrites and nitrates, an indirect measure of nitric oxide (NO) concentration, were lower in CAD patients, and were negatively correlated with ferritin. The increase in ferritin may be related to oxidative stress, suggesting a possible pro-atherosclerotic role of increased ferritin in CAD patients with SDB.
“É preciso escrever um poema várias vezes para que dê a impressão de que foi escrito pela primeira vez". A frase é do poeta Mario Quintana. Guardião do idioma, o poeta sabia como é difícil parecer ...simples. Lapidava suas joias. Na arte, reunia humor, leveza e perspicácia. Um dia – dizia –, o poema cria vida e voa. Logo pousa nos corações e mentes dos leitores, onde se perpetua. O Atlas da Política Brasileira de Defesa que o leitor tem em mãos evoca esse processo. Os mapas são criativos, os gráficos bonitos, as páginas entremeadas, harmonicamente, de raciocínios desafiadores e de obras de arte. Tudo parece simples. As ideias comunicam-se sem ruídos aos leitores, fazendo-lhes ver, de maneira íntegra e concisa, relações de poder a partir de perspectivas teóricas, históricas e geográficas.
COOPERAÇÃO E DESENVOLVIMENTO Maria Regina Soares de Lima; Carlos R. S. Milani; Rubens de S. Duarte ...
Atlas da política brasileira de defensa,
01/2017
Book Chapter
Odprti dostop
Segundo o Livro Branco da Defesa Nacional, a atuação internacional brasileira em matéria de defesa deve primar pela consolidação de estruturas de governança multilaterais, representativas da nova ...distribuição de poder global, voltadas para a paz e a segurança mundiais e para o bem-estar da comunidade internacional. Por isso, o país deve empenhar-se na construção de uma multipolaridade cooperativa, buscando a diversiicação de parcerias e estreitando laços com os países do Sul, não em detrimento de sua relação tradicional com os países do Norte.
Nesse sentido, a partir do inal da década de 1980, o Brasil tem desenvolvido iniciativas de cooperação
GEOPOLÍTICA DA AMÉRICA DO SUL Maria Regina Soares de Lima; Carlos R. S. Milani; Rubens de S. Duarte ...
Atlas da política brasileira de defensa,
01/2017
Book Chapter
Odprti dostop
O artigo 4º da Constituição de 1988 estabelece que o Brasil regerá suas relações internacionais pela cooperação e integração com os países da América Latina. Essa orientação é seguida pelo Livro ...Branco da Defesa Nacional, que descreve que a ênfase da política de defesa do Brasil consiste na cooperação com seu entorno geopolítico imediato, formado pela América do Sul, Atlântico Sul, costa ocidental da África e Antártida. Nas duas últimas décadas, as ações brasileiras no Atlântico Sul e a maior cooperação com os países africanos fortaleceram a presença brasileira nessas regiões, como, por exemplo, por meio da constituição da Zona
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