bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulmonary gas exchange responses to histamine and methacholine challenges in mild asthma
Authors: Echazarreta A.L. , Gómez F.P. , Ribas J. , Sala E. , Barberà J.A. , Roca J. , Rodriguez-Roisin R. 
Published: October 2002

Histamine (HIST) produces greater changes in bronchial and pulmonary vasculature, and so may produce more gas exchange abnormalities, than methacholine (MTH) after inhalational challenge. The goals of this study were to compare the effects of HIST and MTH challenge on pulmonary gas exchange in patients with mild asthma at an equivalent degree of bronchoconstriction.Eleven patients were studied (mean±sem age, 22±1 yr; forced expiratory volume in one second (FEV1), 91±5% pred) using a randomized, double-blind cross-over design. Respiratory system resistance (Rrs), arterial blood gases, and ventilation-perfusion distributions were measured before and after HIST/MTH challenges when cumulative doses caused a 30% fall in FEV1.Compared with baseline, HIST and MTH provoked similar moderate to severe increases inRrs(p<0.005 each), and mild to moderate decreases in arterial oxygen tension (Pa,O2) due to ventilation-perfusion abnormalities (dispersion of pulmonary blood flow -log SDQ-, 0.40±0.03–0.71±0.08 and 0.47±0.04–0.89±0.06; normal values <0.60–0.65), respectively, similar to those shown in mild to moderate acute asthma, without differences between them.For the same degree of airflow obstruction, both histamine and methacholine bronchoprovocations induce, in patients with mild asthma, very similar disturbances in ventilation-perfusion distribution and respiratory system resistance, suggesting similar mechanisms of airway narrowing.
Pulmonary sarcoidosis in children: a follow-up study
Authors: Baculard A. , Blanc N. , Boulé M. , Fauroux B. , Chadelat K. , Boccon-Gibod L. , Tournier G. , Clement A. 
Published: October 2002

Progression of pulmonary sarcoidosis in children remains poorly documented. The aim of this work was to gather follow-up information on pulmonary outcomes in children with sarcoidosis and to obtain data of relevance to a discussion of the optimal length and regimen of glucocorticoid therapy.In the present study, the authors experience of pulmonary sarcoidosis in 21 children referred to the paediatric pulmonary department over a 10-yr period is reported with a documented follow-up of at least 4 yr. Evaluation of the disease during the follow-up included analysis of clinical manifestations, chest radiographs, pulmonary function tests with measurements of the vital capacity (VC), dynamic lung compliance (CL,dyn), lung transfer for CO (TL,CO), and arterial blood gases, as well as bronchoalveolar lavage (BAL) with determination of total and differential cell counts.After initial evaluation the decision was a careful observation of four children without therapy. Corticosteroid treatment was initiated in 17 children. Analysis of results indicated that after 6–12 months of treatment most clinical manifestations of the disease and chest radiograph abnormalities disappeared, and beneficial effects on VC andTL,COwere apparent. After 18 months of steroids no benefit on pulmonary function tests could be noticed, with mainly persistence of alterations ofCL,dyn. Results of BAL studies documented the presence of an alveolitis with increased lymphocyte populations throughout the follow-up. Relapses were observed in four children during tapering of prednisone; they were not reported after discontinuation of steroid therapy.Taken together data obtained in the presented population can lead to the following suggestions for the management of pulmonary sarcoidosis in children. BAL should be performed at the initial evaluation to document alveolitis; however, nothing seems to be gained from repeating this investigation during follow-up in the absence of specific reasons. Once the decision to initiate glucocorticoid therapy is made, 18 months may be a reasonable treatment duration. Discontinuation of therapy can be decided even if the pulmonary function tests remain abnormal, but the child should then be carefully monitored for a relapse.
The influence of fractional pulse pressure on the outcome of pulmonary thromboendarterectomy
Authors: Tanabe N. , Okada O. , Abe Y. , Masuda M. , Nakajima N. , Kuriyama T. 
Published: October 2002

Although pulmonary thromboendarterectomy is an effective modality for the treatment of chronic thromboembolic pulmonary hypertension (CTEPH), the mortality in patients with severe haemodynamic disease is still high. Recently it was reported that fractional pulse pressure (pulmonary arterial pulse pressure/mean pulmonary arterial pressure) was higher in CTEPH than in primary pulmonary hypertension (PPH). It was hypothesized that fractional pulse pressure might be low in CTEPH with inaccessible distal thrombi and/or secondary pulmonary hypertensive change, resulting to the high operative mortality.To determine the influence of fractional pulse pressure to the outcome of surgery, 32 patients with CTEPH who had thromboendarterectomy between 1985 and 1998 were studied. Pulmonary haemodynamics and fractional pulse pressure were compared between survivors (n=26) and nonsurvivors (n=6) postoperatively. Those parameters in PPH (n=18) and large vessel pulmonary arteritis (n=6) were also analysed.Fractional pulse pressure in CTEPH (1.23±0.21) was significantly higher than in PPH (0.93±0.22; p=0.0017) and lower than in pulmonary arteritis (1.69±0.32; p=0.03). Fractional pulse pressure in survivors (1.26±0.21) was significantly higher than in nonsurvivors (1.06±0.16; p=0.03). Fractional pulse pressure is a significant predictor for mortality in patients with high pulmonary vascular resistance >1100 dynes·sec·cm−5.To conclude fractional pulse pressure in addition to pulmonary vascular resistance might be useful in predicting for the outcome of surgery, especially in patients with severe haemodynamic impairment.
Diaphragm fatigue during exercise at high altitude: the role of hypoxia and workload
Authors: Gudjonsdottir M. , Appendini L. , Baderna P. , Purro A. , Patessio A. , Vilianis G. , Pastorelli M. , Sigurdsson S.B. , Donner C.F. 
Published: October 2002

The effect of high altitude (HA) on exercise-induced diaphragm fatigue in normal subjects was examined.Eight normal subjects completed an incremental exercise test at sea level (SL) and at 3,325 m. Before (baseline), during, and after exercise (recovery), maximal transdiaphragm pressure (Pdi,sniff), breathing pattern, and diaphragmatic effort (PTPdi) were measured. Arterialized blood lactate was measured at baseline and during recovery.At maximal exercise (WRmax)Pdi,snifffell to 72% and 61% of baseline at SL and HA respectively, recovering to baseline in 60 min at SL, and >60 min at HA. At the 5th min of recovery, circulating lactate was six-fold and seven-fold baseline at SL and HA, respectively. The time course of circulating lactate recovery was as forPdi,sniff. At WRmaxPTPdiwas 80.74±9.87 kPa·s−1at SL and 64.13±8.21 kPa·s−1at HA. HA WRmaxcompared to isowork rate, SL data showed a lowerPdi,sniff(8.90±0.68versus11.24±0.59 kPa) and higher minute ventilation (117±11versus91±13 L·min−1), PTPdibeing equal.To conclude, in normal subjects hypoxia-related effects, and not an increase in diaphragm work, hastens exercise-induced diaphragm fatigue and delays its recovery at high altitude compared to sea level.
Elastic properties of the lung and the chest wall in young and adult healthy pigs
Authors: De Robertis E. , Liu J.M. , Blomquist S. , Dahm P.L. , Thörne J. , Jonson B. 
Published: October 2002

Understanding of the elastic pressure/volume (Pel/V) curve is still limited in health and disease. The aim of the present study was to elucidate thePel/Vcurve and elastance of the respiratory system (ERS) lung (EL) and chest wall (ECW) in healthy pigs.Six young (20.8 kg) and seven adult (58.9 kg), anaesthetized, paralysed and ventilated pigs were studied.Pel/Vcurves were recorded at zero end-expiratory pressure (ZEEP) and at positive end-expiratory pressure (PEEP) up to 40 cmH2O with a computer controlled ventilator during an insufflation at a low, constant flow.Pel/Vcurves of the respiratory system showed a complex pattern in both young and adult pigs. During the insufflation,ERSdecreased, increased, fell, and increased again. A secondPel/Vcurve recorded immediately after the first one showed lower elastance and only one early fall inERS.ECWfell over the initial segment and was then nearly stable. Difference between 1st and 2nd curves reflected changes in ELcaused by recruitment during the 1st insufflation. At PEEP, such signs of collapse and recruitment were reduced.A strong tendency to lung collapse contributes to a complex pattern of elastic pressure/volume curves. At low volumes and distending pressures the chest wall contributes significantly to changes in respiratory system elastance.
Surfactant protein A and other bronchoalveolar lavage fluid proteins are altered in cystic fibrosis
Authors: von Bredow C. , Birrer P. , Griese M. 
Published: October 2002

Inflammation and proteolytic processes play an important role in the progression of cystic fibrosis (CF) lung disease. The goal of this study was to describe bronchoalveolar lavage fluid (BALF) protein pattern of CF patients in comparison to controls and to assess if there is proteolytic degradation of surfactant protein A (SP-A), an important innate host defence component of the lungs.BALFs from 17 clinically stable CF patients and from eight healthy children were separated by two-dimensional gel electrophoresis. Silver staining was used to show BALF proteins and Western blotting to detect SP-A isoforms.In CF, BALF proteins of a low molecular weight ≤20 kD were more abundant than in controls. Various proteins were seen in CF which were not present in controls andvice versa. Degradation of SP-A was present in 15 of 17 CF BALFs but in none of the controls, in contrast polymeric isoforms were seen in all controls and in four of 17 CF patients.Proteolytic damage to surfactant protein A and significant changes of normal bronchoalveolar lavage fluid proteins occur in lungs of cystic fibrosis patients. Identification of altered bronchoalveolar lavage fluid proteins may give new insights into pathogenic mechanisms and provide new targets for therapy.
Seismic monitoring of fluid fronts: An experimental study
Authors: Wulff Angelika‐M. , Mjaaland Svein 
Published: October 2002

Seismic signatures of time‐dependent reservoir processes, necessary for the interpretation of 4‐D seismic data, are still insufficiently described. This experiment was designed to monitor fluid‐front movements and saturation changes and to identify the related seismic signatures. Ultrasonic P‐ and S‐wave transmission and reflection measurements were used to monitor the waterflooding of a porous sandstone. The sandstone was flooded in steps by filling a tank in which the room‐dry cubic (50‐cm side) block of rock was placed. Waterflooding caused the velocity, amplitude, and frequency of the transmitted waves to diminish significantly; however, the changes were reversible by drying. The maximum reduction of the velocities was 7% and 12% for P‐ and S‐waves, respectively. The velocity and amplitude behavior can be explained by the Biot‐Gassmann's theory, local fluid flow, and grain‐surface effects. The correct interpretation of seismic signatures of fluid processes in reservoirs thus involves a knowledge of rock physical relations and attenuation mechanisms. Even at small saturations, reflections from the block bottom were strongly attenuated, but those from the upgoing water front could be monitored. The latter reflections were best observed in differential seismic traces, confirming that seismic monitoring can observe moving fronts directly.
Airborne TEM surveying with a SQUID magnetometer sensor
Authors: Lee James B. , Dart David L. , Turner Robert J. , Downey Mark A. , Maddever Arthur , Panjkovic Goran , Foley Catherine P. , Leslie Keith E. , Binks Rex , Lewis Christopher , Murray Wayne 
Published: October 2002

Traditionally airborne time-domain electromagnetic (AEM) survey systems use induction coils as the sensor (receiver). We have replaced the induction coil in a transient electromagnetic (TEM) system with a liquid-nitrogen cooled superconducting quantum interference device (SQUID) magnetometer sensor. Using this prototype system, we aimed to improve performance in detecting conductive mineralization, particularly where the conductive mineralization of interest is covered by a conductive regolith. We successfully demonstrated one- and three-component SQUID sensors in airborne TEM surveying, and achieved performance comparable to the induction-coil systems. Implementation of the SQUID system required development of devices capable of operating in magnetically unshielded environments with low noise, high slew rate, and wide bandwidth. Operation of the SQUID sensor in the highly dynamic environment of a towed bird was also necessary, and this implies a high dynamic range and high level of noise associated with the motion in Earth's magnetic field. The high dynamic range of the SQUID response was handled by a combination of resetting the SQUID flux locked loop, reducing the bandwidth, and providing high-gain feedback in parallel with the flux locked loop. A digital stacking filter was used to eliminate low-frequency noise associated with sensor motion. Isolation of the sensor from motion at the TEM signal frequencies required development of a sophisticated suspension system. The SQUID systems were tested over two known conductive targets, and their performance compared with the induction-coil TEM system. A comparative performance measure is developed to take the different sensitivities of the SQUID magnetometer and induction-coil receivers into account. This measure indicates that the SQUID system has superior performance for responses over earth structures with decay time constants greater than ∼6 ms when compared with the induction-coil signals. We also estimate the performance in comparison with integrated outputs of the induction-coil system and show that, at the demonstrated levels of SQUID performance, it is expected to have poorer performance by a factor of two or more. This disadvantage will be reduced for lower frequency, wider channel width TEM configurations or by improvements in the SQUID devices.
In vitro hydrodynamics of the Embol-X cannula
Authors: Gerdes Anja , Hanke Thorsten , Sievers Hans-H 
Published: October 2002

Background: Prevention of intraoperative plaque dislodgement in patients with atherosclerotic ascending aorta by development of innovative aortic cannula designs gains growing interest in cardiac surgery. To increase knowledge about the hydrodynamics of the innovative Embol-X™ cannula, which includes an intra-aortic filter device targeting at atheromatous emboli capture, was the aim of the present study. Methods: Pressure gradients and back pressures of the Embol-X™ cannula were measured at varying flow rates in a mock circulation and compared with two commonly used single-stream cannulae. Results: At a flow rate of 5.5 l/min, pressure gradients across the Argyle™ and the RMI cannulae were 48% and 62% and back pressures 25% and 47% lower than the corresponding values across the Embol-X™ cannula. Conclusions: The novel concept of integrating a filter device may provide clinical advantages concerning neurologic outcome. Further in vivo studies seem to be desirable to obtain more information concerning the clinical effects of the Embol-X™ cannula hydrodynamics.
An in vitro method for comparing biocompatibility of materials for extracorporeal circulation
Authors: Peek Giles J , Scott Richard , Killer Hilliary M , Firmin Richard K 
Published: October 2002

We measured the response of fresh heparinized human blood to recirculation through circuits made of LVA (Portex Industries, Hythe, Kent, UK), SRT (Rehau UK, Langley, Slough, UK) and Tygon® S-65-HL (Norton Performance Plastics, Corby, Northants, UK), as control. Circuit construction: 1/2 in. tubing, heat exchanger (Dideco D-720P), Stockert roller pump, just underoccluded, Cincinnati Sub Zero heater, circuit volume of 500 ml. Flow 3.45 l/min, 37°C. Samples: at 10 min, 1, 2, 4 and 6 h. n= 5 in each group; 2/5 SRT experiments were stopped at 45 and 60 min due to overpressurization. Results: Baseline activated clotting time (ACT) of 300 s, increasing in all groups as fibrinogen fell to zero with SRT and LVA. Minimum fibrinogen was 1 g/l for Tygon. Absolute thrombocytopenia occurred (SRT and LVA 60 min and Tygon 240 min). International normalized ratio (INR) in both the SRT and LVA circuits increased, but mean increase for Tygon (0.56) was smaller than the other two materials. Plasma free haemoglobin increased in all three materials; the increase was greater in the LVA circuits compared to the control. C5b9 levels increased equally in all groups. Lactoferrin levels rose equally in all groups to a maximum at 150 min. The neutrophil counts fell, mirroring the lactoferrin. The total white cell counts also fell in all groups; in the LVA circuits, the fall was significantly lower than in the control. Rapid disappearance of platelets and fibrinogen from the blood in the SRT and LVA circuits excludes them both from extracorporeal use. Paradoxically, SRT caused the least complement activation of the three materials. This method can be used to compare biocompatibility.
Intraoperative treatment strategy to reduce the incidence of postcardiopulmonary bypass atrial fibrillation
Authors: Olivencia-Yurvati A H , Wallace W E , Wallace N , Dimitrijevich D , Knust J K , Haas L , Raven P B 
Published: October 2002

Purpose: Postcardiopulmonary bypass atrial fibrillation remains a constant complication associated with coronary revascularization, the incidence of which occurs from 20% to 35%. Previous studies have addressed this problem in the postoperative setting utilizing pharmacological agents, but the results have been variable. The purpose of this study was to evaluate a novel intraoperative strategy to reduce the incidence of postcardiopulmonary bypass atrial fibrillation. We theorized that leukocyte depletion by filtration with the addition of aprotinin would reduce the systemic inflammatory effects of bypass and reduce the incidence of atrial fibrillation. Methods: One hundred and twenty-two patients participated in this randomized study. Only isolated primary coronary revascularization procedures on cardiopulmonary bypass were included. The control group (n= 55) received standard moderate hypothermic blood cardioplegia cardiopulmonary bypass. The treatment group (n= 65) received similar cardiopulmonary bypass with the addition of strategic leukocyte depletion with Pall Biomedical Products (East Hills, NY) leukodepletion filters and full-dose aprotinin. Results: The intra-operative addition of leukocyte depletion by filtration with aprotinin reduced the incidence of postcardiopulmonary bypass atrial fibrillation by 72%. The incidence of atrial fibrillation in the control group was 27% (15 of 55). In contrast, the occurrence of atrial fibrillation in the treated group was only 7.6% (5 of 65) (p< 0.025). Conclusions: This novel intraoperative treatment strategy of both mechanical (leukocyte filtration) and pharmacological (aprotinin) intervention appears to markedly reduce the incidence of postcardiopulmonary bypass atrial fibrillation. To our knowledge, this is the first study to combine these two treatment strategies. A previous study has noted a decline in atrial fibrillation with aprotinin in the animal model, but not to the extent observed in our study. The beneficial effects of the reduction of atrial fibrillation include reduced risk of emboli formation and the incidence of ischemia in the heart, lung and brain. In addition, a decrease in length of hospital stay, recovery time and overall cost occurred.
The Action Research Arm Test: is it necessary for patients being tested to sit at a standardized table?
Authors: Hsueh I-Ping , Lee Ming-Mei , Hsieh Ching-Lin 
Published: October 2002

Objective: To validate results obtained from using the Action Research Arm Test (ARAT) at tables of a common height for persons who have experienced a stroke. Design: Each subject was tested three times with the ARAT while sitting at three different tables: a table specially designed for the test and two generally available tables similar in height to the standard table. The patients were randomly and equally assigned to three different raters and to three different tables in accordance with a counterbalanced design. All evaluations were completed within a two-day period. Subjects: Sixty-one patients who had had only one stroke (mean age 63.3 years; median time since stroke onset 81 days; mean ARAT score administered at the standard table 33.8) participated in this study. Results: The intraclass correlation coef”cient (ICC) for the total scores obtained using the ARAT at the different tables was 0.99, indicating very high agreement. The ICCs were also very high in each of the subscales. Conclusion: The results of this study support the use of the ARAT at ordinary tables roughly similar in height to that specially designed for use with the ARAT.
Co-morbidity adjustment for functional outcomes in community-dwelling older adults
Authors: Rigler Sally K , Studenski Stephanie , Wallace Dennis , Reker Dean M , Duncan Pamela W 
Published: October 2002

Objective: To characterize relationships between self-reported co-morbidity and functional outcomes in community-dwelling older adults, and to assess whether the impact of co-morbidity persists even after adjustment for baseline functional status. Design: Prospective observational study. We examined associations between self-reported co-morbidity at baseline and functional outcomes at one year, with and without adjustment for baseline functional status. Setting: Outpatient clinics at a managed care and a Veterans Affairs site. Subjects: Four hundred and ”fty-seven community-dwelling older adults representing a broad spectrum of overall health status. Main outcome measures: (a) New basic ADL (activities of daily living) problem during follow-up; (b) 10-point decline in the physical function index of the MOS-36 (MOS-PFI). Results: Co-morbidity was associated with adverse functional outcomes in bivariable analyses. After adjustment for age and baseline functional status, an accumulated co-morbidity score provided additional explanatory power for predicting new ADL problems; odds ratios were 2.30 (1.09, 5.09) and 2.96 (1.48, 6.25) for 2 and 33 affected co-morbidity domains, respectively. The impact of baseline status was also important; odds ratios for new ADL problems were 4.77 (2.68, 8.81) when at least one instrumental activity of daily living (IADL) problem was present at baseline, and 15.6 (8.05, 31.3) when at least one basic ADL problem was present at baseline. Conclusions: Accumulated self-reported co-morbidity has signi”cant negative effects on function at one year; these effects are attenuated but not eliminated by adjustment for baseline status. Co-morbidity adjustment is probably an important design element in clinical research focused on functional outcomes in older adults.