bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nasal and oral contribution to inhaled and exhaled nitric oxide: a study in tracheotomized patients
Authors: Törnberg D.C.F. , Marteus H. , Schedin U. , Alving K. , Lundberg J.O.N. , Weitzberg E. 
Published: October 2002

Nitric oxide (NO) is produced at different sites in the human airways and may have several physiological effects. Orally-produced NO seems to contribute to the levels found in exhaled air. Autoinhalation of nasal NO increases oxygenation and reduces pulmonary artery pressure in humans. The aim of this study was to measure the concentration and output of NO during nasal, oral and tracheal controlled exhalation and inhalation.Ten tracheotomized patients and seven healthy subjects were studied. The mean±sem fraction of exhaled NO from the nose, mouth and trachea was 56±8, 14±4 and 6±1 parts per billion (ppb), respectively. During single-breath nasal, oral and tracheal inhalation the fraction of inhaled NO was 64±14, 11±3 and 4±1, respectively. There was a marked flow dependency on nasal NO output in the healthy subjects, which was four-fold greater at the higher flow rates, during inhalation when compared to exhalation.There is a substantial contribution of nasal and oral nitric oxide during both inhalation and exhalation. Nasal nitric oxide output is markedly higher during inhalation, reaching levels similar to those that are found to have clinical effects in the trachea. These findings have implications for the measurement of nitric oxide in exhaled air and the physiological effects of autoinhaled endogenous nitric oxide.
Noninvasive ventilation after intubation and mechanical ventilation
Authors: Ferrer M. , Bernadich O. , Nava S. , Torres A. 
Published: October 2002

Patients with chronic airflow obstruction who are difficult to wean from mechanical ventilation are at increased risk of intubation-associated complications and mortality because of prolonged invasive mechanical ventilation. Noninvasive positive pressure ventilation may revert most of the pathophysiological mechanisms associated with weaning failure in these patients.Several randomized controlled trials have shown that use of noninvasive ventilation to achieve earlier extubation in difficult-to-wean patients or in patients who develop respiratory failure after apparently successful extubation can result in reduced periods of endotracheal intubation and complication rates and improved survival. However, this is not a consistent finding, and the currently available published data with outcome as the primary variable are exclusively from patients who had pre-existing lung disease. In addition, the patients were haemodynamically stable, with a normal level of consciousness, no fever and a preserved cough reflex.It remains to be seen whether noninvasive positive pressure ventilation has a role in other patient groups and situations, such as prevention of postextubation failure or unplanned extubation. The technique is, however, a useful addition to the therapeutic armamentarium for a group of patients who pose a significant clinical and economic challenge.
Studying human airway pharmacology in microsections: application of videomicrometry
Authors: Schmidt D.T. , Dent G. , Rühlmann E. , Muñoz N.M. , Leff A.R. , Rabe K.F. 
Published: October 2002

The influence of endogenously-released mediators and activated eosinophils on the airway lumen and the effect of passive sensitization on anti-immunoglobulin (Ig)-E-induced contractile responses was investigated by videomicrometry.Human bronchial sections of 2–3 mm internal diameter, placed in 250 µL Hank's balanced salt solution on microtitre plates, were monitored and recorded by digitized image analysis. Airway preparations exhibited a spontaneous narrowing (mean±sem −33±5% of the luminal area). Removal of the bronchial epithelium almost completely prevented the development of spontaneuous narrowing (−6±3%; p<0.001). The addition of platelet-activating factor stimulated human eosinophils to the bronchial sections led to significant narrowing of the airway lumen (−39±9%; p<0.05). Passive sensitization induced hyperresponsiveness to polyclonal anti-IgE (−35±8%; p<0.01).It is concluded that videomicrometry is suitable for studying interactions between human airways and inflammatory cells, as well as the effect of passive sensitization on smooth muscle reactivityin vitro, without the imposition of preload. Under these conditions, human airways exhibited a spontaneous decrease of the airway lumen over time suggesting a role for epithelium-derived mediators because the development of spontaneous tone was epithelium dependent.
Changes of exhaled nitric oxide during steroid treatment of childhood asthma
Authors: Beck-Ripp J. , Griese M. , Arenz S. , Köring C. , Pasqualoni B. , Bufler P. 
Published: October 2002

Exhaled nitric oxide (eNO) is elevated in several inflammatory airway diseases and is significantly reduced by anti-inflammatory treatment with inhaled steroids. The aim of this randomized, open clinical trial was to evaluate eNO in relation to conventional lung function parameters at rest and after exercise during sequential changes of inhaled steroids in children with persistent asthma.The study consisted of a 4 week run-in period, a 4 week washout phase and a randomized treatment period during which only one group was treated again with inhaled budesonide.After run-in, eNO was reduced to normal values, and rose again during washout. In the patients randomized to steroid treatment, eNO was again decreased, whereas it remained unchanged in the untreated patients. Forced expiratory volume in one second and forced vital capacity at rest and after exercise improved significantly after run-in, but showed no difference after randomization. However there was a strong correlation of eNO with patient compliance.Exhaled nitric oxide was able to differentiate between children briefly treated with or without steroids, the conventional lung-function variables however could not. In practice exhaled nitric oxide may thus be a valuable parameter to monitor adherence to steroids, but less suitable to describe physiologically relevant impairments of lung function.
Dyspnoea perception during clinical remission of atopic asthma
Authors: van den Toorn L.M. , Overbeek S.E. , Prins J-B. , Hoogsteden H.C. , De Jongste J.C. 
Published: October 2002

Symptoms of atopic asthma often disappear around puberty. The authors recently demonstrated that this clinical remission is accompanied with ongoing airways inflammation in most subjects. The discrepancy between lack of symptoms and persistent airway inflammation suggests that perception of the symptoms is unclear. In the present study, young adults in clinical remission of atopic asthma assigned themselves a modified Borg score during methacholine and adenosine-5′-monophosphate induced bronchoconstriction. Borg scores of subjects in clinical remission were compared with those of symptomatic asthmatic subjects. A marked variation in the Borg scores at a 20% fall in the forced expiratory volume in one second was found. Significant differences in Borg scores between remission patients and asthmatics could not be detected.It was concluded that perception of dyspnoea, induced with methacholine and adenosine challenge, is similar in young adults in clinical remission of atopic asthma compared to that of patients with symptomatic asthma. Hence, an unclear perception seems to be an unlikely explanation for the discrepancy between lack of symptoms and ongoing inflammation. Other factors, including both physical and psychological ones, may play a role in the apparent absence of symptoms, thereby potentially leading to undertreatment.
Asthma prevalence in children living in villages, cities and refugee camps in Palestine
Authors: El-Sharif N. , Abdeen Z. , Qasrawi R. , Moens G. , Nemery B. 
Published: October 2002

Previous studies have suggested that asthma prevalence is generally lower in the Middle East than in more developed countries. The aim of this study was to investigate the prevalence and severity of asthma and asthma symptoms in schoolchildren in the Ramallah District in Palestine.In the autumn of 2000, 3,382 schoolchildren aged 6–12 yrs were surveyed in 12 schools, using the International Study for Asthma and Allergies in Childhood (ISAAC)-phase III, parents-administered translated questionnaire.The crude prevalence rates for “wheezing-ever”, “wheezing in the previous 12 months”, and “physician-diagnosed asthma” were 17.1, 8.8 and 9.4% respectively, with urban areas having higher prevalence rates than rural areas. Within urban areas, refugee camps had higher prevalence rates than cities. Yet, within the rural areas, the 12-month prevalence was lower in the deprived villages than other residences. Place of residence remained significant for asthma and asthma symptoms, after adjusting for sex, age, and place of birth.To conclude, children from refugee camps appear to be at higher risk of asthma than children from neighbouring villages or cities. The prevalence of asthma and asthma symptoms in Palestine appears to be close to that of Jordan, but it is much lower than Israel, and lower than some other countries in the region, such as Kuwait and Saudi Arabia, and more developed countries. This initial study is a baseline for a study on lifestyle and environmental determinants for asthma among Palestinian children.
Incremental pay thickness modeling of hydrocarbon reservoirs
Authors: Neff Dennis B. 
Published: October 2002

The one-dimensional convolution model or synthetic seismogram provides more information about the seismic waveform expression of hydrocarbon reservoirs when petrophysical data (porosity, shale volume, water saturation, etc.) are systematically integrated into the seismogram generation process. Use of this modeling technique, herein called Incremental Pay Thickness (IPT) modeling, has provided valuable insights concerning the seismic response of several offshore Gulf of Mexico amplitude anomalies. Through integration of the petrophysical data, comparisons between seismic waveform response and expected reservoir pay thickness are extended to include estimates of gross pay thickness, net pay thickness, net porosity feet of pay, and hydrocarbons in place. These 1-D synthetic data easily convert to 2-D displays that often show exceptional waveform correlations between the synthetic and actual seismic data. Anomalous observed waveform responses include complex tuning curves; diagnostic isochron measurements even in unresolved thin-bed reservoirs; and extreme variations in the seismic expression of hydro-carbon-fluid contacts. While IPT modeling examples illustrate both the variability and nonuniqueness of seismic responses to hydrocarbon reservoirs, they often show good seismic predictability of pay thickness if the appropriate choice of amplitude-isochron versus pay thickness is made (i.e., peak amplitude, trough amplitude, or average amplitude versus gross pay thickness, net pay thickness, net porosity feet of pay, or hydrocarbons in place).
Design, calibration, and application of an airborne gamma spectrometer system in Switzerland
Authors: Schwarz Georg F. , Rybach Ladislaus , Klingelé Emile E. 
Published: October 2002

Airborne radiometric surveys are finding increasingly wider applications in environmental mapping and monitoring. They are the most efficient tool to delimit surface contamination and to locate lost radioactive sources. To secure radiometric capability in survey and emergency situations, a new sensitive airborne system has been built that includes an airborne spectrometer with 256 channels and a sodium iodide detector with a total volume of 16.8 liters. A rack mounted PC with memory cards is used for data acquisition, with a GPS satellite navigation system for positioning. The system was calibrated with point sources using a mathematical correction to take into account the effects of gamma‐ray scattering in the ground and in the atmosphere. The calibration was complemented by high precision ground gamma spectrometry and laboratory measurements on rock samples. In Switzerland, two major research programs make use of the capabilities of airborne radiometric measurements. The first one concerns nuclear power plant monitoring. The five Swiss nuclear installations (four power plants and one research facility) and the surrounding regions of each site are surveyed annually. The project goal is to monitor the dose‐rate distribution and to provide a documented baseline database. The measurements show that all sites (with the exception of the Gösgen power plant) can be identified clearly on the maps. No artificial radioactivity that could not be explained by the Chernobyl release or earlier nuclear weapons tests was detected outside of the fenced sites of the nuclear installations. The second program aims at a better evaluation of the natural radiation level in Switzerland. The survey focused on the crystalline rocks of the Central Massifs of the Swiss Alps because of their relatively high natural radioactivity and lithological variability.
Integrated geological and geophysical interpretation case study, and Lamé rock parameter extractions using AVO analysis on the Blackfoot 3C‐3D seismic data, southern Alberta, Canada
Authors: Dufour Jocelyn , Squires Jason , Goodway William N. , Edmunds Andy , Shook Ian 
Published: October 2002

Blackfoot field, southeast of Calgary, Alberta, Canada, has produced oil and gas from a Glauconitic compound incised‐valley system. The Glauconitic compound incised valley has three cycles of incision and valley fill: lower, lithic, and upper incised valleys. The upper and lower incised valleys are the main reservoirs. The geophysical interpretation of compressional PP‐seismic data resulted in the definition of the compound‐valley extent, and in the mapping of the upper and lower incised valleys. A stratigraphic well‐log template was built using the most significant lithological information and well logs. To integrate both geological and geophysical interpretations, the well log cross‐sections and corresponding depth‐converted seismic were superimposed. Furthermore, a detailed geological facies interpretation of the upper and lower incised valleys was undertaken and incorporated. A good correlation was found between the interpreted geological facies and the seismic data response. Information about the nature of the fill within the compound valley was gained from the integration of the PP‐ and PS‐wave interpretations. However, this is limited to Vp/Vs analyses on given intervals. Amplitude‐variation‐with‐offset analysis of the PP‐data was run to discriminate lithology and pore‐fluid saturates. The products of the Lamé rock parameters, incompressibility (λ) and rigidity (μ), with density (ρ) were extracted from seismic inversions for P‐ and S‐impedances. The extraction of λ ρ and μρ showed the presence of gas‐bearing porous sandstone within the Glauconitic incised‐valley system.
The use of quad–quad resistivity in helicopter electromagnetic mapping
Authors: Huang Haoping , Fraser Douglas C. 
Published: October 2002

The apparent resistivity from a helicopter-borne frequency-domain electromagnetic (EM) system is typically obtained from the in-phase and quadrature responses arising from the flow of conduction currents in the earth. The most commonly used resistivity algorithms, derived from half-space models and using single-frequency data, do not account for magnetic polarization and consequently do not yield a reliable value for apparent resistivity in highly magnetic areas. This is because magnetic polarization modifies the EM response, causing the computed resistivity to be erroneously high. The impact of magnetic permeability on the EM response is much greater for the in-phase component than for the quadrature component. If magnetic polarization is to be ignored, the calculation of the apparent resistivity using the quadrature component at two frequencies (the quad–quad algorithm) is less subject to error from magnetic polarization than if the in-phase and quadrature responses at a single frequency are used (the in-phase–quad algorithm). The quad–quad algorithm, however, can display undesirable behavior for large induction numbers, i.e., when conductivities and frequencies are large. Determining which algorithm is optimum is a data-dependent choice, which, of course, is area dependent. We have studied the behavior of the quad–quad (apparent) resistivity and its comparison to in-phase–quad resistivity to determine the conditions under which the use of quad–quad resistivity is appropriate. For a two-layer earth, the behavior of the quad–quad resistivity depends mainly upon the ratio of the lower frequency fL to the upper-layer resistivity ρ1. If this ratio is low, the quad–quad resistivity will behave well. In areas yielding a high value of the ratio fL/ρ1, the quad–quad resistivity may lie outside of the range of the true resistivities of the earth and therefore provide misleading information. Our studies therefore suggest that the quad–quad resistivity algorithm should be avoided in areas where the ratio is large, i.e., when using high frequencies in conductive areas. The term large is relative. For a two-layer case, for example, the use of quad–quad resistivity is only recommended for magnetic areas where fL/ρ1 < 500 Hz/ohm-m, when conductive cover exists, and where fL/ρ1 < 50 Hz/ohm-m when a conductive basement underlies resistive cover. In spite of these limitations, quad–quad resistivity is often preferable to in-phase–quad resistivity in highly magnetic areas.
High-frequency electromagnetic impedance method for subsurface imaging
Authors: Song Yoonho , Kim Hee Joon , Lee Ki Ha 
Published: October 2002

This paper presents a high-frequency electromagnetic (EM) impedance method that extends the utility of conventional controlled-source audio-frequency magnetotelluric (CSAMT) method to the frequency range from 100 kHz to 100 MHz. In this frequency range diffusion and wave propagation must be considered together. In principle, both the electrical conductivity and the permittivity of the shallow subsurface can be imaged using impedance data gathered on the surface of the earth. The impedance approach has a distinct advantage in that coupling with the source is unnecessary, provided that the source can be positioned far enough away to yield plane waves at the receiver positions. At high frequencies the EM impedance is a function of the angle of incidence or the horizontal wavenumber, so the electrical properties cannot be readily extracted without eliminating the effect of horizontal wavenumber on the impedance. For this purpose, this paper considers two independent methods for accurately determining the horizontal wavenumber, which in turn is used to correct the impedance data. The apparent electrical properties derived from the corrected impedance data correlate poorly to the real structure, especially for the model with a resistive overburden. However, the impedance data along with the incidence angles thus estimated can be successfully inverted to yield an accurate subsurface layering through the simulated annealing inversion scheme.
Treatment of Unfavorable Childhood Hodgkin’s Disease With VEPA and Low-Dose, Involved-Field Radiation
Authors: Friedmann Alison M. , Hudson Melissa M. , Weinstein Howard J. , Donaldson Sarah S. , Kun Larry , Tarbell Nancy J. , Link Michael P. 
Published: October 2002

PURPOSE: Between January 1990 and April 1993, 56 pediatric patients with Hodgkin’s disease were treated on a single-arm trial at three institutions with a regimen designed to maintain high cure rates while minimizing the potential late effects of treatment, such as infertility, second malignant neoplasms, and cardiopulmonary injury. PATIENTS AND METHODS: The regimen used combined-modality therapy with six cycles of vinblastine, etoposide, prednisone, and doxorubicin (VEPA) chemotherapy and low-dose, involved-field radiation. Unfavorable features comprised bulky presentations of localized (stage I or II) disease or advanced (stage III or IV) Hodgkin’s disease. RESULTS: Of 56 patients enrolled, 26 (46%) had unfavorable presentations of stage I/II disease and 30 (54%) had advanced (stage III/IV) disease. Seventy-nine percent of the patients are alive without disease at a median follow-up time of 8.9 years from diagnosis. Nineteen patients had events at a median of 1.5 years (range, 0.4 to 7.9 years) from diagnosis; 17 patients relapsed, one died of cardiomyopathy, and one died of accidental injuries. Survival and event-free survival (EFS) estimates at 5 years for the entire cohort were 81.9% (SE, 5.2%) and 67.8% (SE, 6.3%), respectively. Five-year EFS by stage was 100% for stage I, 79.2% (SE, 8.3%) for stage II, 70% (SE, 14.5%) for stage III, and 49.5% (SE, 11.3%) for stage IV patients. CONCLUSION: Combined-modality therapy with VEPA chemotherapy and low-dose, involved-field radiation is adequate for disease control of early-stage patients with unfavorable features, but it is inferior to other standard regimens for advanced-stage patients.
Anxiety Disorders in Cancer Patients: Their Nature, Associations, and Relation to Quality of Life
Authors: Stark D. , Kiely M. , Smith A. , Velikova G. , House A. , Selby P. 
Published: October 2002

PURPOSE: We aimed to estimate the prevalence and types of anxiety disorders diagnosed according to standardized criteria in cancer patients, to compare screening tools in detecting them, and to examine their demographic, oncologic, and psychosocial associations. METHODS: In this cross-sectional observational study of 178 subjects with lymphoma, renal cell carcinoma, malignant melanoma, or plasma cell dyscrasia, we related responses to questionnaires (administered by computer touch-screen) measuring psychological symptoms, quality of life (QOL), and social support to standardized psychiatric interviews and cancer management. RESULTS: Forty-eight percent of subjects reported sufficient anxiety for anxiety disorder to be considered. At subsequent diagnostic interview, 18% fulfilled International Classification of Disorders, 10th Revision criteria for anxiety disorder, including 6% of patients who reported low levels of anxiety by questionnaire. When subjects reported anxiety by questionnaire, if disruptive somatic anxiety was present, this increased the probability of diagnosable anxiety disorder from .31 to .7. The most accurate screening questionnaires were the trait scale of the State-Trait Anxiety Inventory and the Hospital Anxiety and Depression scale. Female sex and negative aspects of social support were associated with anxiety disorder in multivariate analyses. Anxiety disorder was independently associated with a deficit in QOL, particularly insomnia. CONCLUSION: Anxiety symptoms are common in cancer patients. Screening by questionnaire seems to assess anxiety symptoms adequately but discriminates abnormal anxiety inadequately. To improve this, we may need to use criteria such as disruption from anxiety, as illustrated by the impact of anxiety disorders on QOL. There seem to be few oncologic variables that could target screening for anxiety disorders.