Search results for "helium"
showing 10 items of 1689 documents
An experimental model for the exposure of human ciliated cells to sulfur dioxide at different concentrations
1994
Mucociliary transport is an important nonimmunological defense mechanism of the respiratory tract. The aim of this study was to investigate the effect of sulfur dioxide (SO2) at different concentrations on ciliary beat frequency (CBF). Ciliated cells were obtained from 12 volunteers by nose brush. CBF was quantified using video-interference microscopy. The cells were placed on a polycarbonate membrane in contact with the surface of a reservoir filled with RPMI 1640 (bicarbonate buffered) or Ringer's (electrolyte) solution, allowing the cells to be supplied by capillarity. In an exposure chamber the cells were exposed for 30 min to SO2 2.5-12.5 ppm at 37 degrees C and 100% air humidity. SO2 …
Non invasive evaluation of endothelial function in patients with Anderson-Fabry disease.
2005
AIM: Fabry's disease is an X-linked recessive abnormality of glycosphingolipid metabolism. Increased levels of endothelial prothrombotic factors have recently been demonstrated in Fabry's disease, whereas endothelial function has not been studied using high resolution ultrasound. METHODS: We enrolled 6 patients (4 male, 2 female; mean age, 37 years) and 12 sex matched control subjects (mean age, 37 years). Patients' exclusion criteria included a prior history of cardiac disease, diabetes and treated or untreated hypertension. Patients underwent: anamnesis, physical examination, EKG, 2-dimensional echocardiography with tissue Doppler, measurement of body weight and height, blood pressure. Bi…
Parotid sialosis: morphometrical analysis of the glandular parenchyme and stroma among diabetic and alcoholic patients
2009
J Oral Pathol Med (2010) 39: 10–15 Background: Among the agents that cause parotid sialosis, diabetes mellitus type 2 and chronic alcoholism are included. In this study, the morphometrical modifications in the diabetic parotid sialosis were determined to compare them with the histopathological characteristics of alcoholic parotid sialosis. Methods: Five parotid biopsy samples obtained from patients with diabetic sialosis, 12 samples from patients with alcoholic sialosis and seven from individuals without these pathologies (control group) were analyzed. A morphometrical study of parotid parenchyme and stroma, using a digital image analyzer attached to an optical microscope, was carried out…
Basaloid squamous cell carcinoma of the esophagus: diagnosis and prognosis.
1997
BACKGROUND. Basaloid squamous cell carcinoma (BSCC) is a recently recognized, poorly differentiated variant of squamous cell carcinoma (SCC), which is located predominantly in the upper aerodigestive tract. METHODS. In this study, clinical and pathologic parameters of 17 BSCCs and 133 typical SCCs of the esophagus that underwent potentially curative resection (no distant metastases, no residual tumor) were compared. In addition, light microscopic, electron microscopic, and immunohistochemical features of BSCC were investigated, to determine whether this type of carcinoma could be differentiated from other poorly differentiated carcinomas of the esophagus. RESULTS. Light microscopic study sh…
Effect of acute systemic hypoxia on human cutaneous microcirculation and endothelial, sympathetic and myogenic activity
2015
The regulation of cutaneous vascular tone impacts vascular vasomotion and blood volume distribution as a challenge to hypoxia, but the regulatory mechanisms yet remain poorly understood. A skin has a very compliant circulation, an increase in skin blood flow results in large peripheral displacement of blood volume, which could be controlled by local and systemic regulatory factors. The aim of this study was to determine the acute systemic hypoxia influence on blood flow in skin, local regulatory mechanism fluctuations and changes of systemic hemodynamic parameters. Healthy subjects (n=11; 24.9±3.7years old) participated in this study and procedures were performed in siting position. After 2…
Evaluation of inflammatory reactions and genotoxic effects after exposure of nasal respiratory epithelia to benzene.
2003
<i>Background:</i> The aim of this study was to identify inflammatory changes as well as genotoxic effects in cultivated human respiratory epithelial cells after in vitro exposure to benzene. <i>Methods:</i> Primary cell cultures of nasal respiratory mucosa were exposed to synthetic air enriched with 5,000 µg/m<sup>3</sup> of benzene at an air/liquid interface over 8 h and then to synthetic air only over the following 24 h. Controls were continuously exposed to synthetic air over 32 h. To detect inflammatory reactions, release of prostaglandin E<sub>2</sub> was quantified using a competitive enzyme immunoassay. The Comet Assay was used to quan…
Role of cytomegalovirus (CMV)-specific polyfunctional CD8+ T-cells and antibodies neutralizing virus epithelial infection in the control of CMV infec…
2015
The role of cytomegalovirus (CMV)-specific polyfunctional CD8+ T-cells and that of antibodies neutralizing virus epithelial infection (AbNEI) in the control of CMV DNAemia were investigated in 39 CMV-seropositive allogeneic stem-cell transplant (Allo-SCT) recipients with (n = 24) or without (n = 15) CMV DNAemia. AbNEI levels were monitored prospectively by means of a neutralization assay employing retinal epithelial cells (ARPE-19) and the recombinant CMV strain BADrUL131-Y4. Quantification of CMV-specific polyfunctional CD8+ T-cells (expressing two or three of the following markers: IFN-γγ, TNF-α and CD107a) in whole blood was performed by flow cytometry for intracellular cytokine staining…
Reproducibility and Daytime-Dependent Changes of Corneal Epithelial Thickness and Whole Corneal Thickness Measured With Fourier Domain Optical Cohere…
2016
To evaluate the reproducibility of Fourier domain anterior segment optical coherence tomography (RTVue) based on repeated measurements of corneal thickness (CT) and epithelial thickness (ET) and to test daytime-dependent changes of these parameters.Twenty-three eyes from 23 healthy volunteers were included in this prospective study. Three clinical observers performed 3 consecutive measurements each of CT and ET in 3 sessions using RTVue, resulting in 9 measurements per session. Session 1 was performed at 9 AM ± 1 hour, session 2 at 4 PM ± 1 hour on the same day, and session 3 at 9 AM ± 1 hour 2 days later. CT and ET were assessed in 9 areas: corneal vertex, 4 paracentral zones, and 4 periph…
Rosuvastatin Prevents Conduit Artery Endothelial Dysfunction Induced by Ischemia and Reperfusion by a Cyclooxygenase-2–Dependent Mechanism
2010
ObjectivesThe purpose of this study was to determine whether single-dose rosuvastatin (40 mg) protects against ischemia and reperfusion (IR)–induced endothelial dysfunction in humans and whether this effect is cyclooxygenase (COX)-2 dependent.BackgroundAnimal studies have demonstrated that rosuvastatin can limit damage and improve recovery after IR.MethodsIn a double-blind, parallel design, 20 volunteers were randomized to a single dose of oral rosuvastatin (40 mg) or placebo. Twenty-four hours later, endothelium-dependent, flow-mediated dilation (FMD) of the radial artery was measured before and after IR (15 min of upper arm ischemia followed by 15 min of reperfusion). In a separate protoc…
Inhibition of nitric oxide activity by arginine analogs in human renal arteries
2001
Abstract Background: Plasma levels of endogenous guanidine compounds are increased in various pathologic conditions, including chronic renal failure. In the present study we tested the effects of some of these compounds on basal and stimulated nitric oxide activity in human renal arteries. Methods: Rings from human renal arteries were obtained from 22 patients undergoing nephrectomy. The rings were suspended in organ baths for isometric recording of tension. We then studied the effects of N G -monomethyl- l -arginine (L-NMMA), N G , N G -dimethyl- l -arginine (asymmetrical dimethylarginine [ADMA]), aminoguanidine (AG), and methylguanidine (MG) on artery rings under basal and stimulated cond…