bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct binding of Nur77/NAK-1 to the plasminogen activator inhibitor 1 (PAI-1) promoter regulates TNFα-induced PAI-1 expression
Authors: Gruber Florian , Hufnagl Peter , Hofer-Warbinek Renate , Schmid Johannes A. , Breuss Johannes M. , Huber-Beckmann Renate , Lucerna Markus , Papac Nikolina , Harant Hanna , Lindley Ivan , de Martin Rainer , Binder Bernd R.
Published: April 2003

Plasminogen activator inhibitor 1 (PAI-1) is the main fibrinolysis inhibitor, and high plasma levels are associated with an increased risk for vascular diseases. Inflammatory cytokines regulate PAI-1 through a hitherto unclear mechanism. Using reporter gene analysis, we could identify a region in the PAI-1 promoter that contributes to basal expression as well as to tumor necrosis factor α (TNFα) induction of PAI-1 in endothelial cells. Using this region as bait in a genetic screen, we could identify Nur77 (NAK-1, TR3, NR4A1) as an inducible DNA-binding protein that binds specifically to the PAI-1 promoter. Nur77 drives transcription of PAI-1 through direct binding to an NGFI-B responsive element (NBRE), indicating monomeric binding and a ligand-independent mechanism. Nur77, itself, is transcriptionally up-regulated by TNFα. High expression levels of Nur77 and its colocalization with PAI-1 in atherosclerotic tissues indicate that the described mechanism for PAI-1 regulation may also be operative in vivo.
Degenerate specificity of HTLV-1–specific CD8+ T cells during viral replication in patients with HTLV-1–associated myelopathy (HAM/TSP)
Authors: Kubota Ryuji , Furukawa Yoshitaka , Izumo Shuji , Usuku Koichiro , Osame Mitsuhiro
Published: April 2003

Human T-lymphotropic virus type 1 (HTLV-1)–associated myelopathy/tropical spastic paraparesis (HAM/TSP) is an inflammatory neurologic disease caused by HTLV-1 infection, in which HTLV-1–infected CD4+ T cells and HTLV-1–specific CD8+ T cells may play a role in the disease pathogenesis. Patients with HAM/TSP have high proviral loads despite vigorous virus-specific CD8+ T-cell responses; however, it is unknown whether the T cells are efficient in eliminating the virus in vivo. To define the dynamics of HTLV-1–specific CD8+T-cell responses, we investigated longitudinal alterations in HTLV-1 proviral load, amino acid changes in an immunodominant viral epitope, frequency of HTLV-1–specific T cells, and degeneracy of T-cell recognition in patients with HAM/TSP. We showed that the frequency and the degeneracy of the HTLV-1–specific CD8+ T cells correlated well with proviral load in the longitudinal study. The proviral load was much higher in a patient with low degeneracy of HTLV-1–specific T cells compared to that in a patient with comparable frequency but higher degeneracy of the T cells. Furthermore, in a larger number of patients divided into 2 groups by the proviral load, those with high proviral load had lower degeneracy of T-cell recognition than those with low proviral load. Sequencing analysis revealed that epitope mutations were remarkably increased in a patient when the frequency and the degeneracy were at the lowest. These data suggest that HTLV-1–specific CD8+ T cells with degenerate specificity are increased during viral replication and control the viral infection.
A nonsecreted variant of interleukin-4 is associated with apoptosis: implication for the T helper–2 polarization in HIV infection
Authors: Ledru Eric , Février Michèle , Lecoeur Hervé , Garcia Sylvie , Boullier Séverine , Gougeon Marie-Lise
Published: April 2003

We report the detection of an interleukin-4 (IL-4) variant whose expression is tightly associated with deprivation apoptosis. It is detected with the 8D4 anti–IL-4 monoclonal antibody (mAb) not only in T helper-2 (Th2) but also in Th1 clones, and primary T cells, and it is a nonsecreted molecule. It is not expressed during primary necrosis. Our data suggest that de novo IL-4 transcription of an alternative IL-4 mRNA (IL-4δ13) is induced during deprivation apoptosis. In HIV-infected patients, increased expression of IL-4 in T cells is highly correlated to increased apoptosis, restricted to 8D4 reactivity (r2 = 0.84 between % 8D4-8+ and % 7- amino-actinomycin D–positive [7-AAD+] peripheral T cells, P < .0001), and associated with disease progression. The particular reactivity of apoptotic T cells to 8D4 mAb may explain some discordances among studies analyzing the Th1/Th2 balance in HIV infection and questions the function of this intracellular type 2 signal.
Enhancement of ATRA-induced cell differentiation by inhibition of calcium accumulation into the endoplasmic reticulum: cross-talk between RARα and calcium-dependent signaling
Authors: Launay Sophie , Giannı̀ Maurizio , Diomede Luisa , Machesky Laura M. , Enouf Jocelyne , Papp Béla
Published: April 2003

Sarco–endoplasmic reticulum calcium ATPase (SERCA) enzymes control calcium-induced cellular activation by accumulating calcium from the cytosol into the endoplasmic reticulum (ER). To better understand the role of SERCA proteins and cellular calcium homeostasis in all-trans retinoic acid (ATRA)–induced differentiation, we investigated the effect of pharmacologic inhibition of SERCA-dependent calcium uptake into the ER on ATRA-induced differentiation of the HL-60 myelogenous and the NB4 promyelocytic cell lines. SERCA inhibitors di-tert-butyl-benzohydroquinone (tBHQ), thapsigargin, and cyclopiazonic acid significantly enhanced the induction of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and CD11b marker expression induced by suboptimal concentrations of ATRA (50 nM) in both cell lines. Analysis of cellular calcium homeostasis revealed that a 60% mobilization of the total SERCA-dependent intracellular calcium pool was necessary to obtain enhancement of ATRA-dependent differentiation by tBHQ. Moreover, after 3 days of ATRA treatment in combination with tBHQ, NB4 cells showed a significantly decreased calcium mobilization compared with treatments with tBHQ or ATRA alone, suggesting that enhanced differentiation and calcium mobilization are causally related. Interestingly, several ATRA-resistant NB4-derived cell lines were partially responsive to the differentiation-inducing effect of the combination of the 2 drugs. In addition, we found that retinoic acid receptor α (RARα) and PML-RARα proteins are protected from ATRA-induced proteolytic degradation by SERCA inhibition, indicating that cellular calcium homeostasis may interact with signaling systems involved in the control of ATRA-dependent transcriptional activity. By linking calcium to ATRA-dependent signaling, our data open new avenues in the understanding of the mechanisms of differentiation-induction therapy of leukemia.
Non–T-cell–depleted HLA haploidentical stem cell transplantation in advanced hematologic malignancies based on the feto-maternal michrochimerism
Authors: Shimazaki Chihiro , Ochiai Naoya , Uchida Ryo , Okano Akira , Fuchida Shin-ichi , Ashihara Eishi , Inaba Tohru , Fujita Naohisa , Maruya Etsuko , Nakagawa Masao
Published: April 2003

Feto-maternal microchimerism suggests that immunologic tolerance exists between mother and fetus. Based on this hypothesis, we performed haploidentical stem cell transplantation (SCT) without T-cell depletion (TCD) in 5 patients with advanced hematologic malignancies. HLA incompatibilities for graft-versus-host disease (GVHD) direction included 3-loci mismatches in 4 patients, and 2-loci mismatches in one patient. Recipient chimeric cells were detected in all patients. The prophylaxis against GVHD was tacrolimus with minidose methotrexate. Engraftment was obtained in all patients. An acute GVHD of less than or equal to grade 2 developed in all patients except one who developed tacrolimus encephalopathy. Two patients died, 1 from fungal pneumonia and 1 from disease progression. The other 3 patients survived, with one patient in complete remission. These observations suggest that haploidentical SCT based on the feto-maternal microchimerism without TCD is possible.
Regulation of human β2-microglobulin transactivation in hematopoietic cells
Authors: Gobin Sam J. P. , Biesta Paula , Van den Elsen Peter J.
Published: April 2003

β2-Microglobulin (β2m) is a chaperone of major histocompatibility complex (MHC) class I (–like) molecules that play a central role in antigen presentation, immunoglobulin transport, and iron metabolism. It is therefore of importance that β2m is adequately expressed in cells that perform these functions, such as hematopoietic cells. In this study, we investigated the transcriptional regulation of β2m in lymphoid and myeloid cell lines through a promoter containing a putative E box, Ets/interferon-stimulated response element (ISRE), and κB site. Here we show that upstream stimulatory factor 1 (USF1) and USF2 bind to the E box and regulate β2m transactivation. The nuclear factor κB (NF-κB) subunits p50 and p65 bind to the κB box and p65 transactivates β2m. Interferon regulatory factor 1 (IRF1), IRF2, IRF4, and IRF8, but not PU.1, bind to the Ets/ISRE, and IRF1 and IRF3 are strong transactivators of β2m. Together, all 3 boxes are important for the constitutive and cytokine-induced levels of β2m expression in lymphoid and myeloid cell types. As such, β2m transactivation is under the control of important transcriptional pathways, which are activated during injury, infection, and inflammation.
Therapeutic LMP1 polyepitope vaccine for EBV-associated Hodgkin disease and nasopharyngeal carcinoma
Authors: Duraiswamy Jaikumar , Sherritt Martina , Thomson Scott , Tellam Judy , Cooper Leanne , Connolly Geoff , Bharadwaj Mandvi , Khanna Rajiv
Published: April 2003

Development of an epitope-based vaccination strategy designed to enhance Epstein-Barr virus (EBV)–specific CD8+cytotoxic T lymphocytes (CTLs) is increasingly being considered as a preferred approach for the treatment of EBV-associated relapsed Hodgkin disease (HD) and nasopharyngeal carcinoma (NPC). EBV-encoded latent membrane proteins, LMP1 and LMP2, are the only target antigens available for therapeutic augmentation of CTL responses in patients with HD and NPC. Here, we describe preclinical studies using a recombinant poxvirus vaccine that encodes a polyepitope protein comprising 6 HLA A2–restricted epitopes derived from LMP1. Human cells infected with this recombinant polyepitope construct were efficiently recognized by LMP1-specific CTL lines from HLA A2 healthy individuals. Furthermore, immunization of HLA A2/Kb mice with this polyepitope vaccine consistently generated strong LMP1-specific CTL responses to 5 of the 6 epitopes, which were readily detected by both ex vivo and in vitro assays. More important, this polyepitope vaccine successfully reversed the outgrowth of LMP1-expressing tumors in HLA A2/Kb mice. These studies provide an important platform for the development of an LMP-based polyepitope vaccine as an immunotherapeutic tool for the treatment of EBV-associated HD and NPC.
Repeatability of cellular and soluble markers of inflammation in induced sputum from patients with asthma
Authors: in 't Veen JC , de Gouw HW , Smits HH , Sont JK , Hiemstra PS , Sterk PJ , Bel EH
Published: April 2003

Sputum induced by inhalation of nebulized hypertonic saline is increasingly used to monitor airways inflammation in asthma. The aim of this study was to assess the repeatability of measuring cellular and soluble markers of inflammation in whole sputum samples as obtained by sputum induction in patients both with mild and moderate-to-severe asthma. Twelve patients with mild, atopic asthma without inhaled steroid treatment and nine patients with moderate-to-severe, atopic asthma treated with inhaled steroids were studied on two separate days at least 2 days apart. Whole sputum samples, induced by inhalation of hypertonic (4.5%) saline, were homogenized, and analysed for differential cell counts and for concentrations of albumin, fibrinogen, interleukin-8 (IL-8), and eosinophil cationic protein (ECP). Repeatability was expressed as intraclass correlation coefficient (Ri), and as coefficient of repeatability (CR) in percentage cells or in doubling concentration. Samples from two patients with mild asthma contained more than 80% squamous cells and were excluded from analysis. The repeatability for cell differential counts in both groups combined was: for neutrophils, Ri = 0.57 and CR = 31.0; for eosinophils, Ri = 0.85 and CR = 12.4; and for lymphocytes, Ri = 0.76 and CR = 6.9. The repeatability of the fluid phase measurements was: for albumin, Ri = 0.71 and CR = 3.2; for fibrinogen, Ri = 0.88 and CR = 2.8; for IL-8, Ri = 0.66 and CR = 2.2; and for ECP, Ri = 0.82 and CR = 1.1. We conclude that the repeatability of cellular and soluble markers of inflammation in induced sputum from patients with mild and moderate-to-severe asthma is satisfactory. Hence, induced sputum, processed by using the whole expectorated sample, seems to be a valuable method to monitor airway inflammation in asthma.
Role of thromboxane-A2 and cholinergic mechanisms in bronchoconstriction induced by cigarette smoke in guinea-pigs
Authors: Matsumoto K , Aizawa H , Inoue H , Takata S , Shigyo M , Hara N
Published: April 2003

Acute exposure to cigarette smoke provokes bronchoconstriction and increases the concentration of thromboxane (Tx) A2 in bronchoalveolar lavage (BAL) fluid. The purpose of this study was to investigate the role of TxA2 and cholinergic mechanisms in the airway response induced by exposure to cigarette smoke in guinea-pigs. Anaesthetized animals were exposed to 200 puffs of smoke for 10 min. The amount of Evans blue dye extravasated into the bronchial tissue was then measured BAL was performed to determine cell counts and the concentration of TxB2, a stable metabolite of TxA2. The effects of pretreatment with a Tx synthase inhibitor, OKY-046 (10 mg.kg-1), and/or atropine (1 mg.kg-1) were evaluated. Exposure to cigarette smoke caused significant bronchoconstriction (284 +/- 33% of baseline pulmonary resistance (RL)) and plasma extravasation (30.0 +/- 3.8 vs 16.8 +/- 2.6 ng.mg-1 of sham control; main bronchi). OKY-046 or atropine significantly inhibited the bronchoconstriction to a similar extent, without affecting the plasma extravasation. Combined use of these compounds had no additive effect. The cigarette smoke caused significant increase in TxB2 (48 +/- 10 vs 14 +/- 1 pg.mL-1 of sham control) in BAL fluid, which was abolished by OKY-046 but not by atropine. The cellularity in BAL fluid was not different among groups. These results suggest that the bronchoconstriction induced by cigarette smoke is partially mediated by thromboxane A2, which is dependent on a cholinergic pathway.
Thallium-201 scintigraphy in the evaluation of graft dysfunction in lung transplantation. Newark Beth Israel Medical Center Lung Transplant Group
Authors: Karetzky MS , Jasani RR , Zubair MA
Published: April 2003

The object of this study was to evaluate graft dysfunction utilizing thallium-201 scintigraphy in patients who had undergone lung transplantation. We studied 11 patients who had undergone single-lung transplantation and had 44 evaluations for suspected graft dysfunction. All evaluations included a lung thallium-201 scan and chest radiography. In addition, 42 transbronchial biopsies, 19 gallium-67 scans and 28 pulmonary function tests were obtained. Rejection was defined by histopathology and/or the response to an empirical pulse of methylprednisolone, while cultures of protected specimen brushes and blood with a positive chest radiograph were used to define infection. The sensitivity of thallium scintigraphy for diagnosing rejection and/or infection (94%) was higher than that for transbronchial biopsy (86%), gallium scintigraphy (47%), chest radiography (67%), or spirometry testing (30%). Specificity was 100% for thallium scintigraphy and transbronchial biopsy, as compared to chest radiography and spirometry, which were 75 and 80% respectively. This study indicated that thallium-201 scintigraphy is useful for screening lung transplant recipients for episodes of acute rejection and/or infection. A positive scan is confirmation of graft parenchymal dysfunction and may then be followed by empirical treatment or bronchoscopy with transbronchial biopsy and culture to differentiate rejection and infection.
Staging of the mediastinum: value of positron emission tomography imaging in non-small cell lung cancer
Authors: Bury T , Paulus P , Dowlati A , Corhay JL , Weber T , Ghaye B , Schoffers J , Limet R , Albert A , Rigo P , Radermecker M
Published: April 2003

Recent studies have shown limitations of morphological imaging in staging mediastinal lymph node involvement in lung cancer. In contrast to computed tomography (CT), which depends primarily on anatomical imaging features, positron emission tomography (PET) with 18-fluorodeoxyglucose (FDG) depends mainly on the metabolic characteristics of a tissue for the diagnosis of disease. We have performed a prospective study comparing FDG-PET and CT of the thorax in the presurgical assessment of the mediastinum in 50 patients with newly diagnosed non-small cell lung cancer (NSCLC). CT and PET scans were interpreted separately, and results were compared to pathological staging obtained during thoracotomy. Hilar or mediastinal lymph node involvement was present in 58%. In staging for lymph node involvement, CT had a sensitivity of 72% and specificity of 81%, whereas PET had a sensitivity and specificity of 90% and 86%, respectively. When the PET study was compared to histological results, there were four cases showing more advanced mediastinal involvement with PET and four cases showing less involvement with PET. From our preliminary results, we conclude that positron emission tomography with 18-fluorodeoxyglucose is significantly more accurate than computed tomography in the mediastinal staging of non-small cell lung cancer.
Low intensity peripheral muscle conditioning improves exercise tolerance and breathlessness in COPD
Authors: Clark CJ , Cochrane L , Mackay E
Published: April 2003

This randomized, controlled study investigated the physiological effects of a specially designed 12 week programme of isolated conditioning of peripheral skeletal muscle groups. The programme required minimal infrastructure in order to allow continued rehabilitation at home after familiarization within hospital. Forty eight patients, aged 40-72 yrs with chronic obstructive pulmonary disease (COPD) (mean (SD) forced expiratory volume in one second (FEV1) 61 (27)% of predicted normal) were randomly allocated into training (n = 32) and control (n = 16) groups. Physiological assessments were performed before and after the 12 week study period, and included peripheral muscle endurance and strength, whole body endurance, maximal exercise capacity (maximum oxygen consumption (V'O2,max)) and lung function. The training group showed significant improvement in a variety of measures of upper and lower peripheral muscle performance, with no additional breathlessness. Whole body endurance measured by free arm treadmill walking increased by 6,372 (3,932-8,812) 3 (p < 0.001). Symptom-limited maximal V'O2 was unchanged. However, the training group showed a reduction in ventilatory equivalents for oxygen and carbon dioxide, both at peak exercise and at equivalent work rate (Wmax). In summary, low intensity isolated peripheral muscle conditioning is well-tolerated, simple and easy to perform at home. The various physiological benefits should enable patients across the range of severity of chronic obstructive pulmonary disease to improve daily functioning.
Bacterial colonization as a potential source of nosocomial respiratory infections in two types of spirometer
Authors: Burgos F , Torres A , Gonzalez J , Puig de la Bellacasa J , Rodriguez-Roisin R , Roca J
Published: April 2003

The potential risk of spirometers in the transmission of respiratory infections has not been yet established. We performed a prospective cross-sectional study to determine the rate of colonization of a water-sealed spirometer and a pneumotachograph, and the potential risk of cross-transmission of microorganisms to patients using each of these devices. Fifty four patients (aged 51 +/- 18 (mean +/- SD) yrs) were included in the study. All of them had undergone forced spirometry with bronchodilator response by means of the water-sealed spirometer (n = 36) or the pneumotachograph (n = 18). None had a clinically apparent respiratory infection at the time of the study. Routine hygiene measures for respiratory equipment were performed before the study protocol. Samples for microbiological cultures of different parts both of the water-sealed spirometer (proximal and distal tubing, bell and water-bell) and pneumotachograph (proximal and distal tubing) were taken daily before and after the usual series of lung function tests during a 5 day period. Pharyngeal swab cultures were obtained before spirometry and 7 days later in each subject. Thirty six out of a total of 40 (90%) culture samples from the water-sealed spirometer showed microbial growth compared to 4 out of 30 (13%) samples obtained from the pneumotachograph (p < 0.0001). Significant colonization of the water-sealed spirometer was apparent after the third day of the study. The microorganisms most frequently isolated were penicillium sp. (62%), Pseudomonas fluorescens (32%), and Burkholderia cepacea (48%). Distal tubing, water and water-bell were the parts of the water-sealed spirometer that showed higher colonization counts (> or = 10(4) colony-forming units (cfu).mL-1). No transmission sequence of potentially pathogenic microorganisms from equipment to patients or vice versa could be demonstrated. In summary, the water-sealed spirometer frequently became colonized by microorganisms. The potential hazard of such equipment as reservoirs of microorganisms suggests a need for the implementation of new hygiene measures for their maintenance.
Breastfeeding, maternal smoking and lower respiratory tract infections
Authors: Nafstad P , Jaakkola JJ , Hagen JA , Botten G , Kongerud J
Published: April 2003

The objective of the study was to assess the relationship between breastfeeding and lower respiratory tract infections (LRTIs) during the first year of life, with special reference to maternal smoking. A cohort of 3,754 children born in 1992-1993 in the City of Oslo, Norway was recruited and data were collected at birth, 6 and 12 months of age. Complete information was obtained from 3,238 children (follow-up rate 86%). The main outcome was an episode of a LRTI, such as pneumonia, bronchitis or bronchiolitis, based on a self-administered questionnaire addressed to parents when the child was 6 and 12 months old. The outcome was specified as physician-diagnosed. In logistic regression analysis adjusting for confounding, maternal smoking increased the risk of LRTIs in children breastfed for 0-6 months (odds ratio (AOR) 1.7; 95% confidence interval (95% CI) 1.2-2.4), but not essentially when the child was breastfed for more than 6 months (AOR 1.1; 95% CI 0.7-1.6). Short-term breastfeeding (0-6 months) and no maternal smoking was related to an adjusted AOR of LRTIs of 1.3 (95% CI 1.0-1.7), and short-term breastfeeding combined with maternal smoking was related to an adjusted AOR of 2.2 (95% CI 1.6-3.1), as compared with long-term breastfeeding and no maternal smoking. The present study indicates a protective effect of long-term breastfeeding on the risk of lower respiratory tract infection during the first year of life. The results suggest that the protective effect is strongest in children exposed to environmental tobacco smoke.
Relationship between respiratory muscle function and quality of life in sarcoidosis
Authors: Wirnsberger RM , Drent M , Hekelaar N , Breteler MH , Drent S , Wouters EF , Dekhuijzen PN
Published: April 2003

In sarcoidosis, pulmonary and general symptoms often do not correlate with radiographic stage and routinely performed lung function tests. Asymptomatic muscle involvement in sarcoidosis is common, but little is known about respiratory muscle involvement. The aim of this study was to investigate any relationships between persistent complaints and/or quality of life and respiratory muscle strength and endurance, respectively. Measurements of maximal inspiratory and expiratory mouth pressures (PI,max and PE,max), respiratory muscle endurance and routine lung function were made in 18 patients with sarcoidosis. To assess health status and quality of life, patients completed the Sickness Impact Profile (SIP). Respiratory muscle strength and endurance time were lower in the patient group than in a group of healthy controls (p=0.05). Compared to a general population, the patients with sarcoidosis were found to be limited in physical and psychosocial functioning. The respiratory muscle endurance time correlated with the SIP subscales "mobility" (r=-0.56; p<0.01), and "body care and movement" (r=-0.79; p<0.001). The total lung capacity (TLC), inspiratory vital capacity (IVC) and forced expiratory volume in one second (FEV1) were normal in all subjects. In conclusion, patients with sarcoidosis and normal lung function showed reduced respiratory muscle strength and endurance time. Correlations were found between these indices and both symptoms and certain Sickness Impact Profile domains. Therefore, we suggest inclusion of measurements of respiratory muscle strength in the assessment and follow-up of patients with sarcoidosis.
Relationship between allergic manifestations and Toxocara seropositivity: a cross-sectional study among elementary school children
Authors: Buijs J , Borsboom G , Renting M , Hilgersom WJ , van Wieringen JC , Jansen G , Neijens J
Published: April 2003

Toxocara (the cause of visceral larva migrans in humans) and allergy have in common both elevated immunoglobulin E (IgE) levels and eosinophilia. In the present study, we investigated: 1) associations between Toxocara seropositivity and allergic manifestations; 2) risk factors for Toxocara infection; and 3) differences in Toxocara seroprevalence, allergic manifestations and the associations between these two, in children from urban and rural environments. Blood samples from 1,379 Dutch urban and rural elementary schoolchildren, were examined for Toxocara antibodies, eosinophil numbers, total IgE concentrations, and the occurrence of inhaled allergen-specific IgE. Questionnaires investigating respiratory health and putative risk factors for infection were completed. It was found that 8% of the children had Toxocara antibodies, occurring significantly less often in females than in males. The means of total serum IgE levels and blood eosinophils were significantly higher in the Toxocara-seropositive than in the seronegative group. Allergic asthma/recurrent bronchitis was found in 7% of the children, allergic reaction on animal contact in 4%, and IgE to at least one inhaled allergen in 16%. These variables were associated with Toxocara seroprevalence. Inhaled allergen-specific IgE and asthma/recurrent bronchitis occurred significantly less often in rural than in urban areas, and significantly less often among girls than among boys. Furthermore, occurrence of allergen-specific IgE increased significantly with age. No association existed between Toxocara seroprevalence and assumed risks, i.e. contact with pet animals and public playgrounds. In conclusion, our results indicate that allergic manifestations occur more often in Toxocara-seropositive children. A relationship with an already existing allergic condition is plausible.
Short-term knemometry and urine cortisol excretion in children treated with fluticasone propionate and budesonide: a dose response study
Authors: Agertoft L , Pedersen S
Published: April 2003

Few thorough comparisons of the systemic effects of inhaled corticosteroids in children are available. The aim of this study was to compare the effect of budesonide and fluticasone propionate on short-term lower leg growth. Fluticasone propionate, budesonide and placebo were administered for 2 weeks in a randomized, double-blind, double-dummy, cross-over design. Twenty four children aged 6-12 yrs received 200 microg x day(-1) of each drug, or placebo. Another 24 children aged 6-12 years received 400 microg x day(-1) of each drug, or placebo. Dry powder inhalers were used. Lower leg length was measured by knemometry twice a week during all three treatment periods, and 24 h cortisol excretion in the urine was measured at the end of each period. In the low-dose group, lower leg growth rate was the same during treatment with placebo (0.35 mm x week(-1)), fluticasone propionate (0.38 mm x week(-1)) or budesonide (0.26 mm x week(-1)). No significant difference (p=0.39) in lower leg growth rate was found between treatment with 400 microg x day(-1) budesonide (0.30 mm x week(-1)) and 400 microg fluticasone propionate treatment (0.37 mm x week(-1)). Growth rate during treatment with budesonide, 400 microg x day(-1), was significantly lower than during placebo treatment (0.52 mm x week(-1)). Cortisol excretion in the urine during treatment with 200 microg x day(-1) fluticasone propionate was significantly reduced as compared with placebo (p=0.006), but not when compared with 200 microg x day(-1) budesonide (p=0.07). Budesonide 200 microg x day(-1) was not significantly different from placebo. Fluticasone propionate and budesonide, both at 400 microg x day(-1), resulted in a significant reduction in cortisol excretion in the urine as compared with placebo (p=0.001). It is concluded that, dose-for-dose, budesonide Turbuhaler and fluticasone propionate Diskhaler have similar systemic effects.
Short-term ventilatory effects in workers exposed to fumes containing zinc oxide: comparison of forced oscillation technique with spirometry
Authors: Pasker HG , Peeters M , Genet P , Clement J , Nemery B , Van de Woestijne KP
Published: April 2003

Following the occurrence of metal fume fever in some subjects after the installation of an electric furnace in a steel plant, a survey was undertaken to examine whether subjects exposed to fumes containing zinc oxide would exhibit a detectable impairment in ventilatory function, and whether a forced oscillation technique (FOT) was more suited for this detection than conventional spirometry. Pulmonary function measurements were made in 57 exposed workers (production or maintenance) and 55 nonexposed workers (maintenance or strandcasting department) at the beginning and near the end of a work shift (day or night). Maximal expiratory volumes and flows were measured by means of a pneumotachograph, and respiratory resistance (Rrs) and reactance at various frequencies by means of a FOT. These measurements were repeated 1 day later. During the day shift, there were no significant differences in pulmonary function between exposed and control workers. However, during the night shift, an influence of exposure on pulmonary function was revealed both by spirometry and by FOT: workers exposed at night showed a slight decrease in vital capacity (VC) and in forced expiratory volume in one second (FEV1), and a decline in respiratory resistance (Rrs) with oscillation frequency, that were more marked than in unexposed subjects. In contrast to the frequency dependence of Rrs, the changes of lung volumes and expiratory flows were related to differences in initial values between exposed and nonexposed workers. The decrease in FEV1 was maintained the day after exposure. The forced oscillation technique proved at least as sensitive as spirometry to detect small across-shift changes in ventilatory function. Although the effects on pulmonary function were small, it is likely that they represent a subclinical response to the inhalation of small quantities of zinc oxide.
A new use for an old Holter monitor: an ambulatory cough meter
Authors: Chang AB , Newman RG , Phelan PD , Robertson CF
Published: April 2003

Cough is commonly used as an outcome measure in clinical studies, although the subjective reporting of cough is unreliable when compared to objective measures. We describe an inexpensive new ambulatory cough meter that is based on a disused Holter monitor. The cough meter consists of a Holter monitor and a cough processor, designed on a computer to select the most appropriate filters. The cough meter was then validated against the overnight tape recorder on 21 occasions in 18 children (aged 6-15 yrs). The agreement between the cough meter and the tape recorder was good (mean difference of -0.3 coughs x h(-1); limits of agreement -2.2 to 1.7 coughs x h(-1)). We conclude that our newly described ambulatory cough meter provides a valid and inexpensive method of objectively monitoring cough for up to 24 h.
Superior vena cava syndrome caused by encapsulated pleural effusion
Authors: Lai CL , Tsai TT , Ko SC , Yang KY , Perng RP , Chen YM
Published: April 2003

Pleural effusion is often a manifestation of the superior vena cava (SVC) syndrome. However, pleural effusion has never been reported to be a cause of the SVC syndrome. We report the case of a 68 yr old male patient who presented with SVC syndrome and respiratory failure, both attributable to an encapsulated pleural effusion over the right upper mediastinum. Simple drainage was performed as a diagnostic and therapeutic procedure. The pleural effusion was confirmed to be a tuberculous empyema. Chest computed tomography (CT) scan is the most appropriate initial diagnostic procedure for superior vena cava syndrome.
Velocity anisotropy observed in wellbore seismic arrivals: Combined effects of intrinsic properties and layering
Authors: Kebaili Ahmed , Schmitt Douglas R.
Published: April 2003

A method of estimating velocity anisotropy by the τ-p inversion of seismic traveltimes observed in a multi‐depth and offset VSP experiment is developed. In the method, a set of seismic traces observed at a fixed depth in the wellbore are transformed to the τ-p domain. Incidence‐angle‐dependent interval velocities are extracted from the resulting curves using coherency measures after accounting for the effects of the overlaying layers. To test the method, we obtained seismic records from a shallow borehole drilled through a flat lying sedimentary sequence. One depth interval that consists of a homogeneous bioturbated shale is nearly isotropic. A second interval characterized by an alternation of thin (∼1 m) sands and shales displays an anisotropy of 15% with velocities increasing from the near vertical (0 < 30°) to the oblique (30° < 0 < 55°) angles of incidence. Oblique velocities were always larger. The observation that the shale‐sand depth interval displaying the greatest anisotropy also is the most heterogeneous in the sonic logs suggests that the thin layering produces the anisotropy. The theoretical vertical‐to‐horizontal velocity an isotropy for this interval, computed assuming isotropic layering, is 14.2%. Comparing this theoretical value to the vertical‐to‐oblique value obtained over a smaller range of incidence angles indicates that the theoretical value is too small. This discrepancy is possibly because of the intrinsic anisotropy of the shale layers themselves that is not considered in the theoretical calculations.
Response of a multilayered earth with layers having exponentially varying resistivities
Authors: Kim Hyoung‐Soo , Lee Kiehwa
Published: April 2003

The resistivity kernel function for calculating the apparent resistivity of a multilayered earth with layers that have exponentially varying resistivities is derived using a recurrence relation. This relation is applicable to general cases in which layers have either constant or exponentially varying resistivities. A FORTRAN subroutine that computes the apparent resistivity of Schlumberger, Wenner, and pole‐to‐pole array soundings for layers of exponentially varying resistivities is presented. Apparent resistivities of some models computed by the new kernel function are compared with those of the same models approximated by a number of constant resistivity layers. Apparent resistivities computed by both methods show excellent agreement.
Numerical study on the generation of downgoing S‐waves by a vertical force acting close to a step‐like topography
Authors: Yokoi Toshiaki
Published: April 2003

I present detailed numerical experiments on a recently proposed S‐wave generation method and show the excitation characteristics of the downgoing S‐wave caused by a vertical impact acting close to a step‐like topography. The geophysicists’ group of Akita University recently studied and confirmed this phenomenon by in‐situ measurements and named it the “pit effect.” The numerical simulation is performed in 2-D space by the indirect boundary‐element method using the Green’s function for a homogeneous unbounded medium. The results show that the pit effect is a practical S‐wave generator vertical seismic profiling (VSP) and refraction surveys. The generation of a vertical downgoing S‐wave does not require any special machinery, so the pit effect can be used in many situations and especially in remote areas and difficult enviroments such as swamps and steep mountain ranges.
Removal of surface‐related wave phenomena—The marine case
Authors: van Borselen R. G. , Fokkema J. T. , van den Berg P. M.
Published: April 2003

Removal of the effects of the free surface from seismic reflection data is an essential preprocessing step before prestack migration. The problem can be formulated by means of Rayleigh’s reciprocity theorem which leads to an integral equation of the second kind for the desired pressure field that does not include these free‐surface effects. This integral equation can be solved numerically, both in the spatial domain and in the double Radon domain. Solving the integral equation in the double Radon domain has the advantage of reducing the computation time significantly since the kernel of the integral equation becomes dominant diagonally. Two methods are proposed to solve the integral equation: direct matrix inversion and a recursive subtraction of the free‐surface multiples using a Neumann series. Both methods have been developed and tested on a synthetic data set, which was computed with the help of an independent forward‐modeling scheme.
High‐order, finite‐difference modeling of multipole logging in formations with anisotropic attenuation and elasticity
Authors: Mittet Rune , Renlie Lasse
Published: April 2003

A realistic description of the formation seen by an acoustic logging tool includes intrinsic attenuation, anisotropy, and spatial variations of the formation properties. These features are included in finite‐difference (FD) modeling of acoustic full waveform multipole logging. Intrinsic attenuation is included using a phenomenological model that allows for many physical causes of attenuation, including viscous fluid flow losses, to be modeled. Furthermore, the attenuation, the corresponding velocity dispersion, and the elasticity can have any type of axisymmetric anisotropy. To increase computational speed and numerical precision, high‐order FD operators that fully exploit vector processing architecture are used. The problem of using these operators near the symmetry axis in cylindrical coordinates is solved using symmetry arguments. Excellent results are obtained when comparing the calculations with the discrete wavenumber method. When correctly implemented, the FD model has the same numerical precision as the discrete wavenumber method but allows more general formations to be analyzed. Incorrect staggering of the high‐order FD scheme gives artifacts equivalent to the inclusion of a thin layer between the fluid and the formation.
Maximum energy traveltimes calculated in the seismic frequency band
Authors: Nichols Dave E.
Published: April 2003

Prestack Kirchhoff migration using first‐arrival traveltimes has been shown to produce poor images in areas of complex structure. To avoid this problem, I propose a new method for calculating traveltimes that estimates the traveltime of the maximum energy arrival, rather than the first arrival. This method estimates a traveltime that is valid in the seismic frequency band, not the usual high‐frequency approximation. Instead of solving the eikonal equation for the traveltime, I solve the Helmholtz equation to estimate the wavefield for a few frequencies. I then perform a parametric fit to the wavefield to estimate a traveltime, amplitude, and phase. The images created by using these parameters in a Kirchhoff imaging algorithm are comparable in quality to those created using full‐wavefield, finite‐difference, shot‐profile migration.
Radiation patterns: Possibility for monitoring seismic sources
Authors: Carrion Philip , Carcione José , Sampaio Edson E. S.
Published: April 2003

Recent field measurements of the radiation in boreholes indicate that the radiation patterns of real seismic sources are not always in agreement with those corresponding to the point‐source excitation in unbounded homogeneous and isotropic acoustic or elastic media [we refer the reader to Aki and Richards (1980) for the basic discussion on the radiation patterns in homogeneous media]. This mismatch results from the fact that the point‐source radiation patterns corresponding to homogeneous media are too simplistic to satisfy any experiment in the more realistic Earth environment. A study of radiation patterns is certainly important not only to predict possible seismic events but also to analyze the source performance itself by recording seismic arrivals.
Elasticity of partially saturated frozen sand
Authors: Jacoby Maureen , Dvorkin Jack , Liu Xingzhou
Published: April 2003

Seasonal thawing and freezing of near‐surface sediments significantly affect the interpretation of seismic reflection surveys and vertical seismic profiling, as well as activity on the surface. Permafrost covers much of the Earth’s colder regions and is also subject to periodic thawing and freezing. The significance of the regions with large seasonal temperature variations for exploration and engineering activities makes understanding the elasticity of frozen ground an important practical and scientific goal.
Fiber optic time break
Authors: Kepic Anton W. , Russell R. D.
Published: April 2003

Geophysical methods that use explosive seismic sources need to produce an accurate time break signal at the time of the blast. This is generally achieved with a seismic detonator, a special variety of electrical detonator (or cap) that is designed to have minimal latency between the injection of electrical current into the detonator and initiation of the explosion, as well as having a slightly higher base charge and better water resistance. A time‐break signal is obtained by either electronically controlling or monitoring the blast current. Seismic detonators are guaranteed to have better than a millisecond latency if sufficient current is injected into the leads; the necessary current is usually 5 to 10 amps. A millisecond tolerance is acceptable for most seismic work but may not be sufficient for shallow studies or for crosswell tomography. However, in fairness to the seismic detonator, the actual performance is generally better: Burrows (1936) and, independently, Rolland and White (1937) reported a time lag of less than 0.3 ms with a deviation of 0.1 ms. These values have changed little since the 1940s. The MK 2 from C.I.L. Inc. (a division of I.C.I.) has an average lag of 0.3–0.4 ms (personal communication with I.C.I. explosives). Major improvements in electric detonator design have been in the areas of safety and durability. A much greater disadvantage for explosive sources are the strict regulations on the transport and storage of explosive devices (Tour, 1992). The cost of complying with these regulations may prohibit the use of explosives in small surveys or in remote areas. An example is the transport of explosives by aircraft: the only passengers allowed on board are those neccesary for completing the flight and for transporting the explosives. Chartering an aircraft to transport a small amount of explosive material is too costly for many geotechnical and mining geophysics surveys.
Influence of inductive effect on measurements of resistivity through casing
Authors: Kaufman Alexander A. , Karinsky Alexander D. , Wightman William E.
Published: April 2003

A conventional theory of electrical logging through casing, using an alternating field, is developed. Equations for the electric field and its derivative on the borehole axis are derived and their dependence on the resistivity of the medium and parameters of the casing are studied. It is established that within the low‐frequency part of the spectrum, formation resistivity can be determined using the theory of the transmission line. Measurements within the intermediate range of frequencies also give information about the formation resistivity and take into account changes in the casing parameters.
Joint inversion of TEM and distorted MT soundings: Some effective practical considerations
Authors: Meju Maxwell A.
Published: April 2003

Accurate layered‐earth interpretation of magnetotelluric (MT) apparent resistivity sounding curves distorted by the presence of near‐surface, 3-D bodies in an otherwise horizontally stratified ground requires that the curves be shifted to the level they would have assumed in the absence of these anomalous small‐size bodies. The most popular preinterpretation processing involves shifting the biased MT apparent resistivity curves to the levels determined by some additional data. This paper examines the nature of TEM field data, their relationship with MT data, and their usefulness in constraining the interpretation of MT data at locations affected by near‐surface 3-D effects. The MT apparent resistivity curves are neglected in a joint inversion scheme involving the (undistorted equivalent) phase information and TEM data, thus eliminating the need for preinterpretation data processing or correction of statically shifted curves. This approach is efficient and effective, and since an overlapping TEM observational bandwidth is not always required for a successful joint interpretation, simple inexpensive. TEM equipment can be deployed as a logical compliment to MT in deep basin exploration campaigns.
A special circumstance of airborne induced‐polarization measurements
Authors: Smith Richard S. , Klein Jan
Published: April 2003

Airborne induced‐polarization (IP) measurements can be obtained with standard time‐domain airborne electromagnetic (EM) equipment, but only in the limited circumstances when the ground is sufficiently resistive that the normal EM response is small and when the polarizability of the ground is sufficiently large that the IP response can dominate the EM response. Further, the dispersion in conductivity must be within the bandwidth of the EM system. One example of what is hypothesized to be IP effects are the negative transients observed on a GEOTEM® survey in the high arctic of Canada. The dispersion in conductivity required to explain the data is very large, but is not inconsistent with some laboratory measurements. Whether the dispersion is caused by an electrolytic or dielectric polarization is not clear from the limited ground follow‐up, but in either case the polarization can be considered to be induced by eddy currents associated with the EM response of the ground. If IP effects are the cause of the negative transients in the GEOTEM data, then the data can be used to estimate the polarizabilities in the area.