Computed tomography with positron emission tomography is more useful in local than systemic infectious process related to cardiac implanted electrotherapy device: a prospective controlled multicenter diagnostic intervention PET-Guidance Trial.

Assess the diagnostic value of 18-F FDG PET/CT in cardiac implantable electronic devices (CIED) infections in facilitating diagnostic process and optimizing decision-making process.Study group (n = 21) patients with initial suspected diagnosis of CIED-related infection or fever of unknown origin and patients referred for device removal due to infection. Control group (n = 13) patients with implanted CIED, who underwent PET/CT due to other non-infectious indications and had no data for infectious process in follow-up.PET/CT scan showed pocket infection in 12 patients (including 1 in whom infection was not finally diagnosed-the examination was performed early after the implantation procedure-1.5 months), increased tracer uptake in intravascular lead part in 3 patients, and increased uptake in intracardiac part in 5 patients.We found that sensitivity, specificity, positive predictive value, and negative predictive value of the diagnosis made by PET/CT in generator pocket infection was 91.7%, 70%, 78.6%, 87.5% and in lead-dependent intracardiac infection 100%, 47.1%, 35.7%, 100% respectively. PET/CT scan enabled reclassification of diagnosis from possible to definite CIED-related infection in 6 out of 9 patients, and to excluded in 3 out of 9.Establishing diagnosis of device related infections may be challenging due to non-specific symptoms. Incorporation of PET/CT scan in the diagnostic schema can improve accuracy and timing of the diagnosis and help to assess the extent of infection. PET/CT is more useful in local than systemic infectious process related to cardiac implanted electrotherapy device.Trial registration Consent of the bioethics committee nr IK-NP.-0021-85/1465/14. Registration in the www.clinicaltrials.gov database: NCT02196753.

Identifying heat source intensity in treatment of cancerous tumor using therapy based on local hyperthermia - The Trefftz method approachs.

The presented study considers the equation of hyperbolic conduction of heat with perfusion in order to identify such intensity of spatial heat source that will lead to hyperthermia of a cancerous tumor placed in healthy tissue. The tumor is assumed to be in the form of a sphere with a small radius. In order that the determined intensity of the heat source does not damage healthy tissue, different temperature distributions as a function of time are anticipated at the tumor's border. The mathematical tools used are based on the Trefftz method. The results are presented in the form of numbers and graphs illustrating the intensity of the identified heat source and matching the obtained temperature distributions in the tumor to the predicted ones.

Improved robust T-wave alternans detectors.

New statistical and spectral detectors, the modified matched pairs t test, the extended spectral method and the modified spectral method, were proposed for T-wave alternans (TWA) detection gaining robustness according to trend and single-frequency interferences. They were compared to classic detectors such as matched pairs t test, unpaired t test, spectral method, generalized likelihood ratio test and estimated TWA amplitude within a simulation framework and applied to real data. The optimal detection threshold was selected by using a full Monte-Carlo simulation where signals, with and without alternans episodes, were corrupted by Gaussian noise with different power and single-frequency interferences with different tones. All the combinations of noise and frequency were selected and repeated 500 times in order to compute probability of detection ([Formula: see text]) and the false alarm probability ([Formula: see text]), providing ROC curves. The study group consisted of 50 patients with implantable cardioverter-defibrillator (age: [Formula: see text]; LVEF: [Formula: see text]), who were paced (ventricular pacing) at 100 bpm. Two-minute recordings were analyzed. The XYZ orthogonal lead system was used. The best performance was reached by using the modified matched pairs t test (in comparison with the spectral method and other reference methods).

Mechanisms of arsenic-induced cross-tolerance to nickel cytotoxicity, genotoxicity, and apoptosis in rat liver epithelial cells.

The purpose of the present study was to investigate the mechanism of cross-tolerance to nickel in arsenic-transformed cells. Chronic arsenite-exposed (CAsE) cells (TRL 1215 cells, which had been continuously exposed to 0.5 microM arsenite for 20 or more weeks) and control TRL 1215 cells were both exposed to nickel for 24 h, and cell viability was determined by metabolic integrity. The LC(50) for nickel was 608 +/- 32 microM in CAsE cells as compared to 232 +/- 16 microM in control cells, a 2.6-fold increase. CAsE and control cells were treated with 200 microM nickel for 4 h and cellular-free radical production was measured using ESR spectrometry. Hydroxyl radical generation was decreased in CAsE cells. Thiobarbituric acid reactive substances, indicative of lipid peroxidation, and 8-oxo-2'-deoxyguanosine, indicative of oxidative DNA damage, were reduced in CAsE cells. Flow cytometric analysis using Annexin/FITC revealed that nickel-induced apoptosis was reduced in CAsE cells. CAsE cells showed generalized resistance to oxidant-induced toxicity as evidenced by a marked reduction in sensitivity to hydrogen peroxide. Interestingly, intracellular reduced glutathione (GSH) levels were significantly increased in CAsE cells, and when GSH was depleted, CAsE cells lost their nickel resistance. The mechanism of arsenic-induced cross-tolerance to cytotoxicity, genotoxicity, and apoptosis induced by nickel appears related to a generalized resistance to oxidant-induced injury, probably based, at least in part, in increased cellular GSH levels.

Interactions between essential and toxic elements in lead exposed children in Katowice, Poland.

OBJECTIVES: To determine the influence of the essential element status on blood concentrations of lead and other toxic metals. DESIGN AND METHODS: A group of 157 children from Katowice, an industrial area in Poland, was investigated for concentrations of lead and cadmium in whole blood, and mercury, selenium, zinc, copper, and magnesium in whole blood and serum. Relations between these elements, serum ferritin, hematological parameters, as well as serum selenoprotein P and glutathione peroxidase (GSH-px) were examined. Conversion factors for element concentrations (mumol to microgram): lead 207.19, cadmium 112.41, mercury 200.59, selenium 78.96, magnesium 24.31, copper 63.55, and zinc 65. RESULTS: Blood lead was negatively associated with concentrations of selenium in whole blood and serum as well as selenoprotein P and glutathione peroxidase in serum. The association was mainly apparent at low blood lead concentrations, which may indicate an influence of selenium on the kinetics of lead, rather than an effect of lead on the selenium status. Children with low serum ferritin levels had statistically higher blood cadmium levels and a tendency for higher blood lead levels, indicating increased gastrointestinal absorption of these metals at reduced iron stores. Blood lead was negatively correlated with mean corpuscular hemoglobin concentration, which may reflect the effect of lead on hemoglobin synthesis. There was an association between blood mercury and selenium, indicating a common source of intake through fish consumption. CONCLUSIONS: The results indicate that selenium and iron status may influence the kinetics of lead.

Decreased selenium concentration and glutathione peroxidase activity in blood and increase of these parameters in malignant tissue of lung cancer patients.

We studied the selenium (Se) concentration in whole blood and plasma, glutathione peroxidase (GSH-Px) activity in red blood cells and plasma, as well as both of these parameters in cancerous and tumor-free lung tissue of lung cancer patients. Blood samples were taken from 84 cancer patients and 61 healthy controls. Normal and neoplastic lung tissues were obtained from 57 patients at the time of surgery. Se concentrations in whole blood and plasma were lower by 23% (p < 0.001) in patients compared with controls. GSH-Px activity in red cells was lower by 20.2% (p < 0.004) and in plasma by 11.7% (p < 0.05) in patients than in the control group. On the other hand, the tumor Se level was higher by 66.6% (p < 0.0001) and GSH Px activity by 49.5% (p < 0.0001) than in adjacent tumor-free tissue. No differences in Se concentrations and GSH-Px activities were found between squamous cell carcinoma and adenocarcinoma nor among the clinical stages of the disease. In the whole blood and plasma of cancer patients significantly lower Se concentrations were found in smokers than in nonsmokers. Significantly lower Se concentrations were also found among cancer patients who were smokers compared with controls. These findings show that in the blood of cancer the antioxidant ability, as measured by Se and GSH-Px, is reduced significantly. The cause of increased Se and GSH-Px in the malignant part of the lung is not understood and requires further studies.

Changes in blood selenium and glutathione concentrations and glutathione peroxidase activity in human pregnancy.

Whole-blood and plasma selenium (Se) concentrations, red blood cell and plasma glutathione peroxidase activities, and red blood cell glutathione concentrations were investigated in 49 healthy pregnant women. Mean whole-blood and red blood cell Se concentrations started to decline after the 16th week and plasma Se after the 26th week of pregnancy. The lowest values were noted just before delivery. Negative correlations were found between the gestational age and both whole-blood and plasma Se concentrations: (r = -0.560 (p < 0.001) and r = -0.553 (p < 0.001), respectively. Plasma and red blood cell glutathione peroxidase activities started to decrease after the 20th and 30th week of pregnancy, respectively, and before delivery were significantly lower (p < 0.001) than during the 10th week of pregnancy. The red blood cell glutathione concentration increased significantly just before delivery. These results seem to confirm the supposition that in pregnant women with low or even moderate blood Se concentrations the requirement for the element significantly increases.

Non-operative removal of a parotid duct stone with a balloon angioplasty catheter.

We illustrate a rapid and simple method for removal of a stone from the parotid duct using a balloon angioplasty catheter and digital subtraction imaging. No anaesthesia or surgical intervention is necessary.

Blood selenium concentrations and glutathione peroxidase activities in patients with breast cancer and with advanced gastrointestinal cancer.

Recent prospective epidemiological studies have shown an association between a low prediagnostic serum selenium (Se) concentration and the risk of cancer. Se concentrations in whole blood and plasma, and the activity of red cell and plasma glutathione peroxidase (GSH-Px) were measured in patients with breast cancer, gastric cancer and colorectal cancer. The observed whole blood and plasma Se concentrations of healthy persons were 99.5 and 78.5 micrograms/L, respectively. Red cell and plasma GSH-Px activities of this group were: 21.0 U/g Hb and 256 U/L plasma. In all investigated cancer patients significantly lower whole blood and plasma Se concentrations, and significantly lower red cell and plasma GSH-Px activities were found, as compared with the values of healthy controls. Low Se concentrations of blood components may be indicative of increased cancer risk.