bluuebunny/crossref_metadata_2025_split huggingface dataset:
How is difficult asthma managed?
Authors: Roberts N. J. , Robinson D. S. , Partridge M. R. 
Published: June 2006

Most patients with asthma can be easily treated. Some have difficult asthma; in some because the diagnosis is erroneous, in others because of comorbidity or noncompliance. A European Respiratory Society Task Force has called for an integrated approach for these patients, and positive results have been reported using protocols. In the UK, there is no overall understanding of the size of this problem, or how these patients are managed.A postal survey of 683 consultant members of the British Thoracic Society designed to elicit respondents' views on how they would manage four clinical scenarios was conducted.There was a 50.4% response rate. Few reported a uniform approach to the investigation of such patients. The availability of allied healthcare professionals was variable. The 21 consultant respiratory physicans, reporting a special interest in difficult asthma, were significantly more likely to objectively assess compliance, perform skin-prick tests and to utilise a liaison psychiatrist than those without an expressed special interest in asthma. Many reported difficulty in accessing psychologists, liaison psychiatrists and social workers. Approaches to the diagnosis and management of “vocal cord dysfunction” were variable.The results of this postal survey of specialist thoracic physicians in the UK suggest that a protocol for difficult asthma is not in widespread use and that access to necessary allied healthcare professionals is not uniform. Pulmonologists with a declared special interest in difficult asthma may have configured their services and approaches more in line with that proposed by the European Respiratory Society Task Force.
Sildenafil treatment for portopulmonary hypertension
Authors: Reichenberger F. , Voswinckel R. , Steveling E. , Enke B. , Kreckel A. , Olschewski H. , Grimminger F. , Seeger W. , Ghofrani H. A. 
Published: June 2006

Portopulmonary hypertension (POPH) is regarded as a subtype of pulmonary arterial hypertension (PAH); however, established PAH therapies have not been evaluated for this condition.The current authors treated 14 patients (four male, 10 female; mean (range) age 55 (39–75) yrs) with moderate (n = 1) or severe (n = 13) POPH caused by alcoholic liver disease (n = 7), chronic viral hepatitis (n = 3), autoimmune hepatitis (n = 3), and hepatic manifestation of hereditary haemorrhagic teleangiectasia (n = 1) with oral sildenafil. Eight patients were newly started on pulmonary vasoactive treatment, while six patients were already on treatment with inhaled prostanoids (iloprost, n = 5; treprostinil, n = 1). During treatment with sildenafil, mean±sd6-min walk distance increased from 312±111 m to 397±99 m after 3 months, and 407±97 m after 12 months. Mean±sdpro-brain natriuretic peptide levels decreased from 582±315 ng·mL-1to 230±278 ng·mL-1, and to 189±274ng·mL-1after 3 and 12 months, respectively. Two patients died after 1 and 2 months from liver failure and cardiac failure, respectively. There was a similar response to sildenafil treatment after 3 and 12 months in patients on monotherapy and those on combination therapy.In conclusion, sildenafil might be effective in monotherapy and in combination therapy with inhaled prostanoids in portopulmonary hypertension, leading to significant improvement by 3 months and sustained response over 12 months.
Healthcare workers with tuberculosis infected during work
Authors: de Vries G. , Šebek M. M. G. G. , Lambregts-van Weezenbeek C. S. B. 
Published: June 2006

The risk for healthcare workers (HCWs) of tuberculosis (TB) attributable to occupational exposure is difficult to determine, as are the conditions contributing to this risk. The objective of the present study was to determine which TB cases among HCWs in the Netherlands were infected during work and to analyse factors which contributed to infection and subsequent disease.The total study population consisted of 101 cases over a 5-yr period. In 67 (66%) subjects the route of infection could be determined by epidemiological and microbiological information. Of these cases, 28 out of 67 (42%) were due to infection at work, 19 (28%) were community acquired, and 20 (30%) were infected abroad.The 28 cases infected at work were subject to an in-depth analysis. Delayed diagnosis of the index case, especially in the elderly patient, was the main cause of patient-to-HCW transmission. In some circumstances, inadequate infection-control measures also contributed to transmission.In conclusion, a high suspicion of tuberculosis by the clinician, adequate infection control measures by hospital authorities, and early identification of latent tuberculosis infection by occupational and public-health specialists are necessary to prevent tuberculosis among healthcare workers.
Anti-inflammatory cytokines in cystic fibrosis lung disease
Authors: Starosta V. , Ratjen F. , Rietschel E. , Paul K. , Griese M. 
Published: June 2006

Lung inflammation plays a pivotal role in the pathogenesis of airway disease in cystic fibrosis (CF). An imbalance between pro- and anti-inflammatory mediators has been observed and a deficiency in the anti-inflammatory response has been proposed, but this concept remains controversial.In the present study, the concentrations of two anti-inflammatory mediators, lipoxin A (LxA4) and Clara cell protein 10 (CC-10), were assessed in bronchoalveolar lavage fluid (BALF) of CF patients with a wide range of endobronchial inflammation and disease controls with neutrophilic inflammation unrelated to CF.No differences were observed in LxA4BALF concentrations between CF patients and controls with a similar degree of neutrophilic airway inflammation. Concentrations were also similar in CF patients with mildversusmore severe airway inflammation. In contrast, CC-10 concentrations were lower in CF patients, but this decrease was limited to patients with more intense airway inflammation.The present data do not support the concept of a primary defect in anti-inflammatory mediators in cystic fibrosis lung disease. Although Clara cell protein concentrations were found to be reduced, these alterations appear to be secondary to neutrophilic airway inflammation rather than due to a primary deficiency.
Endobronchial ultrasound-guided transbronchial needle aspiration of lymph nodes in the radiologically normal mediastinum
Authors: Herth F. J. F. , Ernst A. , Eberhardt R. , Vilmann P. , Dienemann H. , Krasnik M. 
Published: June 2006

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) can sample enlarged mediastinal lymph nodes in patients with nonsmall cell lung cancer (NSCLC). To date, EBUS-TBNA has only been used to sample nodes visible on computed tomography (CT). The aim of the present study was to determine the accuracy of EBUS-TBNA in sampling nodes ≤1 cm in diameter.NSCLC patients with CT scans showing no enlarged lymph nodes (no node >1 cm) in the mediastinum underwent EBUS-TBNA. Identifiable lymph nodes at locations 2r, 2l, 4r, 4l, 7, 10r, 10l, 11r and 11l were aspirated. All patients underwent subsequent surgical staging. Diagnoses based on aspiration results were compared with those based on surgical results.In 100 patients (mean age 58.9 yrs; 68 males), 119 lymph nodes ranging 5–10 mm in size were detected and sampled. Malignancy was detected in 19 patients but missed in two; all diagnoses were confirmed by surgical findings. The mean diameter of the punctured lymph nodes was 8.1 mm. The sensitivity of EBUS-TBNA for detecting malignancy was 92.3%, specificity was 100%, and the negative predictive value was 96.3%. No complications occurred.In conclusion, endobronchial ultrasound-guided transbronchial needle aspiration can accurately sample even small mediastinal nodes, therefore avoiding unnecessary surgical exploration in one out of six patients who have no computed tomography evidence of mediastinal disease. Potentially operable patients with no signs of mediastinal involvement on computed tomography may benefit from pre-surgical endobronchial ultrasound-guided transbronchial needle aspiration and staging.
Physical activity is independently related to aerobic capacity in cystic fibrosis
Authors: Hebestreit H. , Kieser S. , Rüdiger S. , Schenk T. , Junge S. , Hebestreit A. , Ballmann M. , Posselt H-G. , Kriemler S. 
Published: June 2006

It is unclear whether a relationship between physical activity (PA) and maximal oxygen uptake (V′O2,max) exists in cystic fibrosis (CF) and, if so, whether the relationship reflects a direct effect or is mediated by the effects of confounding variables, such as pulmonary or muscle function. The objective of the present study was to determine the relationship between PA andV′O2,maxin CF while adjusting for possible influences of confounding factors.In total, 36 female and 35 male patients with CF from Germany and Switzerland (aged 12–40 yrs, forced expiratory volume in one second (FEV1) 25–107% predicted) were studied. A Wingate test was employed to measure muscle power. PA was monitored for 7 days and expressed in two ways: 1) average daily accelerometer count (ADAC) and 2) time spent in moderate-to-vigorous PA (MVPA).V′O2,maxwas determined during an incremental cycle exercise test to volitional fatigue.PA was positively related toV′O2,max. In a multiple linear regression analysis, height, sex, FEV1, muscle power and ADAC (additionally explained variance 2.5%) or time spent in MVPA (additionally explained variance 3.7%) were identified as independent predictors ofV′O2,max.In conclusion, high levels of physical activity in addition to good muscular and pulmonary functions are associated with a high aerobic capacity in cystic fibrosis.
Nontuberculous mycobacteria in bronchiectasis: prevalence and patient characteristics
Authors: Fowler S. J. , French J. , Screaton N. J. , Foweraker J. , Condliffe A. , Haworth C. S. , Exley A. R. , Bilton D. 
Published: June 2006

The aim of the current study was to investigate the prevalence and clinical associations of nontuberculous mycobacteria (NTM) in a well-characterised cohort of patients with adult-onset bronchiectasis.The sputum of all patients attending a tertiary referral bronchiectasis clinic between April 2002 and August 2003 was examined for mycobacteria as part of an extensive diagnostic work-up. NTM-positive patients subsequently had further sputa examined. A modified bronchiectasis scoring system was applied to all high-resolution computed tomography (HRCT) scans from NTM-positive patients, and a matched cohort without NTM.Out of 98 patients attending the clinic, 10 had NTM in their sputum on first culture; of those, eight provided multiple positive cultures. Three patients were treated for NTM infection. A higher proportion of NTM-positive than -negative patients were subsequently diagnosed with cystic fibrosis (two out of nineversustwo out of 75). On HRCT scoring, more patients in the NTM-positive group had peripheral mucus plugging than in the NTM-negative group.In the current prospective study of a large cohort of patients with bronchiectasis, 10% cultured positive for nontuberculous mycobacteria in a random clinic sputum sample. Few clinical parameters were helpful in discriminating between groups, except for a higher prevalence of previously undiagnosed cystic fibrosis and of peripheral mucus plugging on high-resolution computed tomography in the nontuberculous mycobacteria group.
Potential misclassification of causes of death from COPD
Authors: Jensen H. H. , Godtfredsen N. S. , Lange P. , Vestbo J. 
Published: June 2006

Little is known about causes of death in chronic obstructive pulmonary disease (COPD) and the validity of mortality statistics in COPD. The present authors examined causes of death using data from the Copenhagen City Heart Study.Of the 12,979 subjects with sufficient data from the baseline examination during 1976–1978, 6,709 died before 2001. Of these, 242 died with COPD as cause of death. Among subjects with at least severe COPD at baseline, only 24.9% had COPD as cause of death and, in almost half of the cases where COPD was listed as cause of death, the subject had a normal forced expiratory volume in one second /forced vital capacity ratio at baseline.In COPD patients, having COPD on the death certificate was associated with chronic mucus hypersecretion (CMH) at baseline, an odds ratio (OR) of 3.6 (95% confidence interval 1.7–7.7), and being female (OR 2.7 (1.3–5.6)). In subjects without COPD, CMH and smoking were predictors of COPD as underlying cause of death, ORs 2.3 (1.5–3.7) and 2.2 (1.4–3.6), respectively.It was concluded that chronic obstructive pulmonary disease is underreported on death certificates, that biases in the use of chronic obstructive pulmonary disease as cause of death can be assessed, and that possible “over-diagnosis” of chronic obstructive pulmonary disease on death certificates in subjects unlikely to have significant disease should initiate caution when using causes of mortality in chronic obstructive pulmonary disease epidemiology.
System Complexity As a Measure of Safe Capacity for the Emergency Department
Authors: France Daniel J. , Levin Scott 
Published: June 2006

ObjectivesSystem complexity is introduced as a new measure of system state for the emergency department (ED). In its original form, the measure quantifies the uncertainty of demands on system resources. For application in the ED, the measure is being modified to quantify both workload and uncertainty to produce a single integrated measure of system state.MethodsComplexity is quantified using an information‐theoretic or entropic approach developed in manufacturing and operations research. In its original form, complexity is calculated on the basis of four system parameters: 1) the number of resources (clinicians and processing entities such as radiology and laboratory systems), 2) the number of possible work states for each resource, 3) the probability that a resource is in a particular work state, and 4) the probability of queue changes (i.e., where a queue is defined by the number of patients or patient orders being managed by a resource) during a specified time period.ResultsAn example is presented to demonstrate how complexity is calculated and interpreted for a simple system composed of three resources (i.e., emergency physicians) managing varying patient loads. The example shows that variation in physician work states and patient queues produces different scores of complexity for each physician. It also illustrates how complexity and workload differ.ConclusionsSystem complexity is a viable and technically feasible measurement for monitoring and managing surge capacity in the ED.
Surge Capacity Associated with Restrictions on Nonurgent Hospital Utilization and Expected Admissions during an Influenza Pandemic: Lessons from the Toronto Severe Acute Respiratory Syndrome Outbreak
Authors: Schull Michael J. , Stukel Therese A. , Vermeulen Marian J. , Guttmann Astrid , Zwarenstein Merrick 
Published: June 2006

BackgroundCurrent influenza pandemic models predict a surge in influenza‐related hospitalizations in affected jurisdictions. One proposed strategy to increase hospital surge capacity is to restrict elective hospitalizations, yet the degree to which this measure would meet the anticipated is unknown.ObjectivesTo compare the reduction in hospitalizations resulting from widespread nonurgent hospital admission restrictions during the Toronto severe acute respiratory syndrome (SARS) outbreak with the expected increase in admissions resulting from an influenza pandemic in Toronto.MethodsThe authors compared the expected influenza‐related hospitalizations in the first eight weeks of a mild, moderate, or severe pandemic with the actual reduction in the number of hospital admissions in Toronto, Ontario, during the first eight weeks of the SARS‐related restrictions.ResultsInfluenza modeling for Toronto predicts that there will be 4,819, 8,032, or 11,245 influenza‐related admissions in the first eight weeks of a mild, moderate, or severe pandemic, respectively. In the first eight weeks of SARS‐related hospital admission restrictions, there were 3,654 fewer hospitalizations than expected in Toronto, representing a modest 12% decrease in the overall admission rate (a reduction of 1.40 admissions per 1,000 population). Therefore, influenza‐related admissions could exceed the reduction in admissions resulting from restricted hospital utilization by 1,165 to 7,591 patient admissions, depending on pandemic severity, which corresponds to an excess of 0.44 to 2.91 influenza‐related admissions per 1,000 population per eight weeks, and an increase of 4% to 25% in the overall number of admissions, when compared with nonpandemic conditions.ConclusionsPandemic modeling for Toronto suggests that influenza‐related admissions would exceed the reduction in hospitalizations seen during SARS‐related nonurgent hospital admission restrictions, even in a mild pandemic. Sufficient surge capacity in a pandemic will likely require the implementation of other measures, including possibly stricter implementation of hospital utilization restrictions.
Design of DNA-Cleaving Agents
Authors: Saito Isao , Nakatani Kazuhiko 
Published: June 2006

Abstract
The review focuses on the molecular design of artificial sequence-specific DNA-cleavers which have recently been developed in our laboratories. These include: DNA cleavers mimicking natural antitumor antibiotic like enediyne antibiotics, bleomycins, and kapurimycin A3. The design of photochemical DNA-cleaving molecules is also described. These are classified as: i) nonselective DNA cleavers, ii) thymine selective DNA cleavers, iii) photo-Fenton reagents, iv) photoinducible DNA alkylating agents, and v) DNA cleavers via photoinduced electrontransfer. The scope and limitation of these DNA-cleaving agents are described with a special emphasis on the concept and strategy for designing novel sequence-specific DNA cleavers, as well as on the mechanistic aspects of their DNA cleavage.
Derivative-State Analysis of a Sequential Intramolecular Vibrational Energy Re-distribution
Authors: Someda Kiyohiko 
Published: June 2006

Abstract
The Mori expansion adapted to pure-state dynamics is shown to be useful for analyzing a sequential intramolecular vibrational energy re-distribution (IVR). The expansion produces non-stationary basis states, “derivative states”, which form a chain of mutually interacting quantum states beginning at a given initial state. An analysis based on this chain clearly demonstrates how the Hilbert space of quantum states is explored in sequential IVR. The derivative states can be classified into several “generations”, and, thereby, a genealogy of quantum states can be discussed.
A Theoretical Study on the Oxidative Addition of a Si–H σ-Bond to [MCl(CO)(PH3)2] (M = Rh or Ir). Similarities to and Differences from [M′(PH3)2] (M′ = Pd or Pt) and [RhCl(PH3)2]
Authors: Sakaki Shigeyoshi , Ujino Yuka , Sugimoto Manabu 
Published: June 2006

Abstract
The Si–H Oxidative Addition to [MCl(CO) (PH3)2] (M = Rh or Ir) was theoretically investigated with ab initio MO/MP2—MP4, SD-CI, and CCD (coupled cluster with double substitutions) methods. This reaction proceeds with a somewhat high activation energy (Ea) and a moderate exothermicity (Eexo); when the oxidative addition occurs in the Cl–M–CO plane, Ea = 19 kcal mol−1 for Rh and 13 kcal mol−1 for Ir, and Eexo = 0.4 kcal mol−1 for Rh and 17.4 kcal mol−1 for M = Ir. This result is in significant contrast to [M′(PH3)2] (M′ = Pd or Pt) and [RhCl (PH3)2] : the Si–H oxidative addition occurs with a very small barrier for [M′(PH3)2], but a zero barrier and significantly high exothermicity for [RhCl(PH3)2]. The low reactivity of [MCl(CO)(PH3)2] is interpreted in terms of the low energy level of the d orbital, a considerable weakening of the M–Cl and M–CO bonds, and an exchange repulsion between SiH4 and the M d orbital in [MCl(CO)(PH3)2]. The above results indicate that Vaska-type complexes are less favorable for an oxidative addition reaction than [M′(PH3)2] and [RhCl(PH3)2], and that they cannot be used for a catalytic reaction including an oxidative addition which requires a high activation energy.
Mean Activity Coefficients of Simple Electrolytes in Polyelectrolyte Solutions
Authors: Kakehashi Rie 
Published: June 2006

Abstract
Mean activity coefficients of NaCl, NaNCS, or Na2SO4 were evaluated on the basis of the Donnan salt distribution in sodium polyacrylate (α = 0.3, 0.5, 0.8, and 1.0), sodium polystyrenesulfonate, poly(2-methacryloxyethyltrimethylammonium) chloride or polyallylamine hydrochloride solutions. Observed mean activity coefficients were close to those given by Manning’s limiting law (LL) at polyelectrolyte concentration me = 0.001 mol kg−1 in all systems examined. The observed activity coefficients showed large deviations from LL at high me and for Na2SO4 but they were in fair agreement with the theoretical values when corrected for the contribution from the small ion–small ion interaction.
High Pressure Raman Study of Hexafluorobenzene Crystals
Authors: Suzuki Yoshio , Shimada Hiroko , Shimada Ryoichi 
Published: June 2006

Abstract
Pressure effects on the Raman active inter- and intramolecular vibrations of hexafluorobenzene crystals were studied under hydrostatic pressures up to about 5 GPa at room temperature in a gasketed diamond anvil cell. The observed Raman spectra indicate that very gradual application of pressure to hexafluorobenzene liquid up to about 0.3 GPa gives rise to supercompressed liquid and the supercompressed liquid crystallizes in phase I by further successive applications of pressure. On the other hand, hexafluorobenzene liquid crystallizes in phase II by quick application of pressure up to about 0.8 GPa. The crystal structure in phase I grown via supercompression is unchanged up to about 2—4 GPa, depending on the experimental conditions and finally transfers to phase II. Coexistence of the crystal phases I and II gives complex spectral structures in both the inter- and intramolecular vibrational regions under various pressures. The pressure-induced frequency shift of the intermolecular vibrations of hexafluorobenzene crystal is compared with those of hexachloro- and hexabromobenzene crystals and it is shown that the repulsive force between the bromine atoms belonging to different molecules is stronger than the repulsive forces between the fluorine atoms and also between the chlorine atoms.
Stereostructural and Vibrational Analyses of cis-Polyacetylene Based on Density Functional Calculations of Oligoenes
Authors: Hirata So , Torii Hajime , Tasumi Mitsuo 
Published: June 2006

Abstract
The total energies and optimized structures of all-trans-transoid (Tt), all-cis-transoid (Ct), all-trans-cisoid (Tc), and all-cis-cisoid (Cc) oligoenes with various chain lengths were calculated using the Becke3–Lee–Yang–Parr (B3LYP) hybrid functional with the 6-31G* basis set. The optimized structures of the Tt and Ct oligoenes were found to be planer, whereas the Tc and Cc oligoenes have helical structures in which the conformations about the C–C bonds deviate from planar s-cis. The total energies of the Tt, Ct, Tc, and Cc oligoenes with the same chain length increase in this order. The vibrational force fields of the Ct and Tc oligoenes were calculated at the B3LYP/6-31G* level. The structures and force fields of the Ct and Tc polyacetylene were estimated by analyzing the chain-length dependence of the structural parameters and force constants of the oligoenes. The normal frequencies and the inelastic neutron scattering spectra were calculated for Ct and Tc polyacetylene on the basis of the thus-obtained structures and force fields. A comparison between the calculated and observed results clearly indicates that as-polymerized cis-rich polyacetylene consists of planar Ct chains. The comparison also suggests that the observed Raman bands of cis-rich polyacetylene films arise from Ct segments with intermediate conjugation lengths.