Impact of mitochondria and NADPH oxidases on acute and sustained hypoxic pulmonary vasoconstriction.

Hypoxic pulmonary vasoconstriction (HPV) matches lung perfusion with ventilation to optimize pulmonary gas exchange. However, it remains unclear whether acute HPV (occurring within seconds) and the vasoconstrictor response to sustained alveolar hypoxia (developing over several hours) are triggered by identical mechanisms. We investigated the effect of mitochondrial and NADPH oxidase inhibitors on both phases of HPV in intact rabbit lungs.

Development and validation of MCNP4C-based Monte Carlo simulator for fan- and cone-beam x-ray CT.

An x-ray computed tomography (CT) simulator based on the Monte Carlo N-particle radiation transport computer code (MCNP4C) was developed for simulation of both fan- and cone-beam CT scanners. A user-friendly interface running under Matlab 6.5.

Assessment of different computational models for generation of x-ray spectra in diagnostic radiology and mammography.

Different computational methods based on empirical or semi-empirical models and sophisticated Monte Carlo calculations have been proposed for prediction of x-ray spectra both in diagnostic radiology and mammography. In this work, the x-ray spectra predicted by various computational models used in the diagnostic radiology and mammography energy range have been assessed by comparison with measured spectra and their effect on the calculation of absorbed dose and effective dose (ED) imparted to the adult ORNL hermaphroditic phantom quantified. This includes empirical models (TASMIP and MASMIP), semi-empirical models (X-rayb&m, X-raytbc, XCOMP, IPEM, Tucker et al.

Monte carlo simulation of x-ray spectra in diagnostic radiology and mammography using MCNP4C.

The general purpose Monte Carlo N-particle radiation transport computer code (MCNP4C) was used for the simulation of x-ray spectra in diagnostic radiology and mammography. The electrons were transported until they slow down and stop in the target. Both bremsstrahlung and characteristic x-ray production were considered in this work.

Finite-size effect on magnetic ordering temperatures in long-period antiferromagnets: holmium thin films.

The thickness dependence of the helical antiferromagnetic ordering temperature T(N) was studied for thin Ho metal films by resonant magnetic soft x-ray and neutron diffraction. In contrast with the Curie temperature of ferromagnets, T(N) was found to decrease with film thickness d according to [T(N)(infinity)-T(N)(d)]/T(N)(d) proportional variant (d-d(0))(-lambda(')), where lambda(') is a phenomenological exponent and d(0) is of the order of the bulk magnetic period L(b). These observations are reproduced by mean-field calculations that suggest a linear relationship between d(0) and L(b) in long-period antiferromagnets.

Association of asthma with gastroesophageal reflux disease in children.

Background: The objective in this study was to assess the association of gastroesophageal reflux disease (GERD) with asthma in pediatric patients.

Methods: Thirty-six pediatric patients who were diagnosed as having bronchial asthma were included in the study. The male-to-female ratio was 2 to 1.

Techniques for the detection of coronary atherosclerosis: multi-detector row CT coronary angiography.

Purpose: To investigate the accuracy of different computed tomographic (CT) reformation techniques in assessing the coronary arteries.

Materials And Methods: Sixty-four patients undergoing both multi-detector row CT and invasive coronary angiography were consecutively included in a retrospective study. CT scans were obtained with collimation of 4 x 1 mm, pitch of 1.

[Visualization techniques in multislice CT-coronary angiography of the heart. Correlations of axial, multiplanar, three-dimensional and virtual endoscopic imaging with the invasive diagnosis].

Objective: To evaluate the performance of 4 different visualization techniques for multislice CT datasets from the coronary arteries in comparison to coronary angiography.

Material And Methods: 42 patients were examined prospectively using both multislice CT and angiocardiography. All CT scans were performed at collimation 4 x 1 mm, pitch 1.

Effect of moderate alcohol intake on lipid peroxidation in plasma, erythrocyte and leukocyte and on some antioxidant enzymes.

Plasma, erythrocyte and leukocyte lipid peroxidation, erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and plasma gamma-glutamyl transferase (GGT) levels were investigated in 36 healthy non-drinkers aged between 18-55 years (mean 38.7) and 72 alcohol drinkers aged between 20-48 years (mean 35.3) in order to determine the oxidative effect of alcohol.