bluuebunny/crossref_metadata_2025 huggingface dataset:
Actions Speak Louder Than Functions: The Importance of Manipulability and Action in Tool Representation
Authors: Kellenbach Marion L. , Brett Matthew , Patterson Karalyn
Published: February 2003

PET was used to investigate the neural correlates of action knowledge in object representations, particularly the left lateralized network of activations previously implicated in the processing of tools and their associated actions: ventral premotor cortex (VPMCx), posterior middle temporal gyrus (PMTG), and intraparietal sulcus (IPS). Judgments were made about the actions and functions associated with manipulable man-made objects (e.g., hammer); this enabled us to measure activations in response to both explicit and implicit retrieval of knowledge about actions associated with manipulable tools. Function judgments were also made about nonmanipulable artifacts (e.g., traffic light) providing a direct comparison for manipulable objects. Although neither the left VPMCx nor the left PMTG were selective for tool stimuli (nonmanipulable objects also activated these areas relative to a visual control condition), both regions responded more strongly to manipulable objects, suggesting a role for these cortical areas in the processing of knowledge associated with tools. Furthermore, these activations were insensitive to retrieval task, suggesting that visually presented tools automatically recruit both left VPMCx and left PMTG in response to action features that are inherent in tool representations. In contrast, the IPS showed clear selectivity for explicit retrieval of action information about manipulable objects. No regions of cortex were more activated by function relative to action judgments about artifacts. These results are consistent with the brain's preferential responsiveness to how we interact with objects, rather than what they are used for.
Common and Segregated Neuronal Networks for Different Languages Revealed Using Functional Magnetic Resonance Adaptation
Authors: Chee Michael W. L. , Soon Chun Siong , Lee Hwee Ling
Published: February 2003

The effect of word repetition within and across languages was studied in English-Chinese bilinguals who read rapidly presented word pairs in a block design and an event-related fMRI study. Relatively less increase in MR signal was observed when the second word in a pair was identical in meaning to the first. This occurred in the English-only and mixed-languages conditions. Repetition-induced reductions in BOLD signal change were found in the left lateral prefrontal and lateral temporal regions in both types of conditions in the block experiment, suggesting that processing in these regions is sensitive to semantic features present in words and characters, and that part of the semantic neuronal networks serving English and Chinese is shared. In addition, these regions showed greater absolute signal change in the mixed-languages trials relative to the English-only trials. These findings were mostly replicated in an event-related experiment. Together, the experiments suggest that while the networks for Chinese and English word processing have shared components, there are also components that may be language specific.
Time Course of Processes and Representations Supporting Visual Object Identification and Memory
Authors: Schendan Haline E. , Kutas Marta
Published: February 2003

Event-related potentials (ERPs) were used to delineate the time course of activation of the processes and representations supporting visual object identification and memory. Following K. Srinivas (1993), 66 young people named objects in canonical or unusual views during study and an indirect memory test. Test views were the same or different from those at study. The first ERP repetition effect and earliest ERP format effect started at ∼150 msec. Multiple ERP repetition effects appeared over time. All but the latest ones were largest for same views, although other aspects of their form specificity varied. Initial ERP format effects support multiple-views-plus-transformation accounts of identification and indicate the timing of processes of object model selection (frontal N350 from 148–250 to 500–700 msec) and view transformation via mental rotation (posterior N400/P600 from 250–356 to 700 msec). Thereafter, a late slow wave reflects a memory process more strongly recruited by different than same views. Overall, the ERP data demonstrate the activation of multiple memory processes over time during an indirect test, with earlier ones (within 148–400 msec) characterized by a pattern of form specificity consistent with the specific identification-related neural process or representational system supporting each memory function.
Long-Latency ERPs and Recognition of Facial Identity
Authors: Olivares Ela I. , Iglesias Jaime , Rodríguez-Holguín Socorro
Published: February 2003

N400 brain event-related potential (ERP) is a mismatch negativity originally found in response to semantic incongruences of a linguistic nature and is used paradigmatically to investigate memory organization in various domains of information, including that of faces. In the present study, we analyzed different mismatch negativities evoked in N400-like paradigms related to recognition of newly learned faces with or without associated verbal information. ERPs were compared in the following conditions: (1) mismatching features (eyes-eyebrows) using a facial context corresponding to the faces learned without associated verbal information (“pure” intradomain facial processing); (2) mismatching features using a facial context corresponding to the faces learned with associated occupations and proper names (“nonpure” intradomain facial processing); (3) mismatching occupations using a facial context (cross-domain processing); and (4) mismatching names using an occupation context (intra-domain verbal processing). Results revealed that mismatching stimuli in the four conditions elicited a mismatch negativity analogous to N400 but with different timing and topo-graphical patterns. The onset of the mismatch negativity occurred earliest in Conditions 1 and 2, followed by Condition 4, and latest in Condition 3. The negativity had the shortest duration in Task 1 and the longest duration in Task 3. Bilateral parietal activity was confirmed in all conditions, in addition to a predominant right posterior temporal localization in Condition 1, a predominant right frontal localization in Condition 2, an occipital localization in Condition 3, and a more widely distributed (although with posterior predominance) localization in Condition 4. These results support the existence of multiple N400, and particularly of a nonlinguistic N400 related to purely visual information, which can be evoked by facial structure processing in the absence of verbal-semantic information.
FEMALE MATING SWARMS INCREASE PREDATION RISK IN A 'ROLE-REVERSED' DANCE FLY (DIPTERA: EMPIDIDAE: RHAMPHOMYIA LONGICAUDA LOEW)
Authors: Gwynne Darryl , Bussière Luc
Published: February 2003

Mate acquiring activities often expose males to increased risks of predation. In species where females are more competitive than males (i.e. a reversal in the conventional mating roles), the mate-acquiring biology of females is expected to increase their exposure to predators. Our observational study of a role-reversed dance fly, Rhamphomyia longicauda Loew (Empididae), supports this prediction. Within predominantly female swarms, R. longicauda display structures in flight that are assessed by males. Structural and behavioural components of the display should increase the risk of predation on females. We found more females than males captured in spider webs. This bias in predation was not due to a female-bias in population sex-ratios of the dance fly and the nature of web predation appears to rule out the hypothesis that spiders actively favour females as prey.
SIZE-ASSORTATIVE PAIRING IN THE BIG-CLAWED SNAPPING SHRIMP, ALPHEUS HETEROCHELIS
Authors: Rahman Nasreen , Dunham  , Govind
Published: February 2003

The big-clawed snapping shrimp, Alpheus heterochelis, is found in size-matched male-female pairs. A common assumption is that a large size advantage in males, an extended pair bond, and a positive correlation between female size and fecundity promotes size-assortative pairing. Since all of these conditions apply to A. heterochelis, we investigated size-assortative pairing in the laboratory by designing experiments in which the pairs were size matched or mismatched using three size categories; large, medium and small. We found that snapping shrimps prefer to pair according to size and that such pairing is stable. We also found that, contrary to the initial assumptions, female-female competition and female choice for large males plays the main role in the pair formation process. Smaller, and hence less competitively successful, females will pair with smaller males, but in a male-biased environment, will preferentially pair with larger males. Large males provide the best protection from shelter eviction, which is crucial for female A. heterochelis, as their reproduction is closely associated with moult, and therefore requires shelter and a male present for successful reproduction.
MATERNAL CARE IN THE NEOTROPICAL HARVESTMAN BOURGUYIA ALBIORNATA (ARACHNIDA: OPILIONES): OVIPOSITION SITE SELECTION AND EGG PROTECTION
Authors: Machado Glauco , Oliveira Paulo
Published: February 2003

Females of the harvestman Bourguyia albiornata oviposit almost exclusively inside the tube formed by the curled leaves of the bromeliad Aechmea nudicaulis. Oviposition is not correlated with rainfall or with temperature, but is negatively correlated with the number of individuals of A. nudicaulis emitting flowers. Because the inflorescence stalk occupies the tube of leaves of flowering bromeliads, oviposition site is not available for ovigerous females. During one year, 83.6% of the females produced only one egg-batch and the remaining produced two or three batches. The mean number of eggs per batch along successive reproductive events decreased significantly. A field experiment in which females were removed from the nest bromeliad showed that less than 7% of the unprotected eggs survived beyond two weeks. In a control in which females were maintained over the eggs, predators attacked only one egg-batch. Ants were the most important egg predators, and at the study site at least 20 species nest and/or forage in A. nudicaulis. Intense predation on eggs by generalist predators may be an important pressure promoting parental care in Neotropical harvestmen.
Eotaxin protein and gene expression in guinea-pig lungs: constitutive expression and upregulation after allergen challenge
Authors: Li D , Wang D , Griffiths-Johnson DA , Wells TN , Williams TJ , Jose PJ , Jeffery PK
Published: February 2003

Eotaxin is an eosinophil-specific chemoattractant originally identified in bronchoalveolar lavage fluid after allergen challenge of sensitized guinea-pigs. We have determined and quantified for the first time the cellular sources of guinea-pig lung eotaxin and localized gene expression in structural cells of large and small airways and in alveolar macrophages. We used anti-guinea-pig eotaxin monoclonal and polyclonal antibodies and a complementary ribonucleic acid (cRNA) probe to detect eotaxin protein and cytoplasmic messenger ribonucleic acid (mRNA) transcripts by the techniques of immunohistochemistry and in situ hybridization in: 1) naive; 2) ovalbumin-sensitized/ saline-exposed; and 3) ovalbumin-sensitized/ovalbumin-challenged animals (n = 5 for each group). Compared with the naive animals, there was a fivefold increase of eotaxin protein and a 25 fold upregulation of eotaxin gene expression in the airway epithelium 3 h after ovalbumin challenge of sensitized animals (p < 0.001). The average percentages of alveolar macrophages staining for eotaxin protein and mRNA in the naive animals were approximately 30 and 10% respectively: both increased significantly in the sensitized/ovalbumin-challenged animals to 78 and 57%, respectively (p < 0.0001). Compared with the naive animals, the procedure of sensitization and saline exposure significantly increased eotaxin gene expression in both bronchial epithelium and alveolar macrophages (p < 0.01): the upregulation at these two sites showed a strong positive association (rcorr = 0.95; p < 0.0001). The results indicate that there are multiple cellular sources of guinea-pig lung-derived eotaxin, including bronchial and bronchiolar epithelial cells, airway smooth muscle, bronchial vascular endothelium, and chondrocytes and alveolar macrophages, and that there are relatively rapid and marked increases of eotaxin protein and gene expression in airway epithelium and alveolar macrophages following allergen challenge.
Biophysical and physiological properties of a modified porcine surfactant enriched with surfactant protein A
Authors: Sun B , Curstedt T , Lindgren G , Franzen B , Alaiya AA , Calkovska A , Robertson B
Published: February 2003

Surfactant protein A (SP-A), a major protein component of natural pulmonary surfactant, is absent in exogenous surfactants currently used in clinical practice. We investigated the physical and physiological properties of one of these modified natural surfactants (Curosurf) after enrichment with 5% SP-A (SP-A-Curosurf). A pulsating bubble system was used for in vitro assessments and ventilated newborn rabbits for evaluation of in vivo effects. In the presence of various potential inhibitors (meconium 5 mg.mL-1, fibrinogen 5 mg.mL-1, albumin 25 mg.mL-1, or whole serum proteins 25 mg.mL-1), Curosurf at a concentration of 5 mg.mL-1 was inactivated while SP-A-Curosurf and natural porcine surfactant at the same concentration had normal maximum and minimum surface tension. This protective effect of SP-A was calcium dependent. In immature newborn rabbits, the improvement of lung-thorax compliance observed after treatment with 100 mg.kg-1 of SP-A-Curosurf was equivalent to that obtained with 200 mg.kg-1 of Curosurf. Similarly, in near-term newborn rabbits with respiratory failure induced by instillation of fibrinogen via the airways, the increase in compliance after administration of 100 mg.kg-1 of SP-A-Curosurf corresponded to that seen after treatment with 200 mg.kg-1 of Curosurf, whereas Curosurf at a dose of 100 mg.kg-1 had no substantial effect. Our data thus indicate that surfactant protein A increases the resistance of Curosurf to inactivation under in vivo conditions.
Correlation between nasal potential difference measurements, genotype and clinical condition in patients with cystic fibrosis
Authors: Ho LP , Samways JM , Porteous DJ , Dorin  , Carothers A , Greening AP , Innes JA
Published: February 2003

In cystic fibrosis (CF), the clinical condition of patients correlates poorly with genotype. One possible explanation is that clinical status is influenced by net preserved chloride secretion rather than the CF mutation. We tested the relationships between residual chloride secretion, as measured by nasal potential difference (PD) and the type of mutation (genotypes expressing apical cystic fibrosis transmembrane conductance regulator (CFTR) protein versus those that do not) and clinical status. Twenty two CF patients (mean age 25.7 yrs, 11 females and 11 males, mean forced expiratory volume in one second (FEV1) 53.1% of predicted) with defined genotypes were recruited. Nasal PD was measured using a standard protocol involving the perfusion of the nasal epithelium with a sodium channel blocker (amiloride), followed by a solution of low chloride and finally with isoprenaline. Patients with apical CFTR protein showed higher residual chloride secretion than those without (amiloride to isoprenaline value of 4.59 and 0.56 mV, respectively, p = 0.01). There was no correlation between mutation type and clinical condition. When these patients were recategorized as "high" (> 10 mV amiloride to isoprenaline response) or "low" (10 mV or less) chloride secretors, we found that the former group had a significantly higher FEV1 (67.7 versus 48.3% pred) and a better pulmonary radiological score (4.14 versus 7.07, by Northern scoring system). These results suggest that some cystic fibrosis patients, regardless of genotype, have an ability to secrete chloride when stimulated with chloride secretatagogues, and this is correlated with a better lung function. These results also have implications for the use of potential difference measurements in novel cystic fibrosis transmembrane conductance regulator replacement trials.
Lung deposition from the Turbuhaler in children with cystic fibrosis
Authors: Devadason SG , Everard ML , MacEarlan C , Roller C , Summers QA , Swift P , Borgstrom L , Le Souef PN
Published: February 2003

Drug delivery to patients using dry powder inhalers, such as the Turbuhaler, is believed to be influenced by the inspiratory flow used. Clinical studies have indicated that this delivery system can be used effectively by children. However, it is not known how the total and weight-corrected dose delivered to the airways varies with age. A deposition study using technetium-99m (99mTc)-labelled budesonide was performed in order to determine the effect of age on delivery. Twenty one children with cystic fibrosis, aged 4-16 yrs, were recruited. They were clinically stable with normal lung function. Initially, a gamma camera scan was taken in front of a flood source containing 37 MBq of 99mTc. Subsequently, subjects inhaled through a low resistance inspiratory filter connected to a commercially available Turbuhaler. Immediately afterwards they inhaled from a noncommercial Turbuhaler containing budesonide labelled with 99mTc, and then underwent anterior and posterior gamma camera scans. Both Turbuhaler inhalers were attached to a portable spirometer and the peak inspiratory flow through the Turbuhaler was recorded for each inhalation. The total body dose was calculated from the dose deposited on the inspiratory filter connected to the commercial Turbuhaler. Analysis of the gamma camera images provided information on the proportion of the radiolabel delivered to the lungs compared to that deposited in the upper airway and stomach. As expected, a highly significant positive correlation was noted between the peak inspiratory flow generated by the patient through the Turbuhaler and the dose delivered to the lung. Similarly, there was a highly significant positive correlation between age and "total lung dose". However, when total lung dose was corrected for body weight, there was a nonsignificant negative correlation with age. This study suggests that the "weight-corrected lung dose" achieved when children aged > 6 yrs use the Turbuhaler, is largely independent of age. It would appear that the flow-dependent properties of this device are such that the reduced peak inspiratory flow generated by younger children results in a lower dose to the lungs, but that this is off-set by their lower body weight. This is unlikely to be a property of other devices with different flow/drug delivery characteristics.
Elevation of antibodies to cytomegalovirus and other herpes viruses in pulmonary fibrosis
Authors: Yonemaru M , Kasuga I , Kusumoto H , Kunisawa A , Kiyokawa H , Kuwabara S , Ichinose Y , Toyama K
Published: February 2003

The aim of this study was to determine whether latent viral infection is associated with idiopathic pulmonary fibrosis (IPF), an interstitial lung disease whose aetiology remains to be elucidated. Cytomegalovirus (CMV) immunoglobulin G (IgG) and complement fixation (CF), Epstein-Barr (EB) viral capsid antigen (VCA) IgG, herpes simplex virus (HSV) IgG, adenovirus CF, and parainfluenza 3 virus haemagglutinin inhibition (HI) titres were measured in the serum from patients with pulmonary diseases. The study included five subject groups: 35 normal controls (aged (mean +/- SD) 38 +/- 17 yrs); 43 IPF (63 +/- 10 yrs), seven collagen vascular disease-related interstitial pneumonitis (CVD-IP) (62 +/- 12 yrs); 22 sarcoidosis (36 +/- 14 yrs); and 17 emphysema (66 +/- 11 yrs). Levels of CMV IgG in IPF (87.6 +/- 51.7) and CVD-IP (101.2 +/- 69.9) were significantly elevated compared to those in the control (30.9 +/- 24.1), sarcoidosis (34.4 +/- 38.3) and emphysema groups (40.3 +/- 24.6), whereas CMV immunoglobulin M (IgM) was generally below the limit of detection. Similarly, CMV CF titres in IPF and CVD-IP were elevated compared to those in other diseases. EB VCA IgG titres in IPF, CVD-IP and emphysema and HSV IgG in IPF were also elevated. In contrast, adenovirus CF and parainfluenza 3 HI titres demonstrated no significant difference among all of the groups investigated. Increases in cytomegalovirus immunoglobulin G and complement fixation titres with negative cytomegalovirus immunoglobulin M suggest that latent cytomegalovirus infection may be more prominent in idiopathic pulmonary fibrosis or collagen vascular disease-related interstitial pneumonitis. Together with the elevation of Epstein-Barr virus viral capsid antigen and herpes simplex virus immunoglobulin G in idiopathic pulmonary fibrosis and/or collagen vascular disease-related interstitial pneumonitis, it is rational to assume that these viruses may be implicated in the development of pulmonary fibrosis. Further study is necessary to investigate the relationship between latent viral infection and pulmonary fibrosis.
Long-term outcome of pulmonary function in farmer's lung: a 14 year follow-up with matched controls
Authors: Erkinjuntti-Pekkanen R , Kokkarinen JI , Tukiainen HO , Pekkanen J , Husman K , Terho EO
Published: February 2003

The long-term outcome of pulmonary function was evaluated in farmer's lung (FL) patients compared to representative control farmers. This is, to our knowledge, the first such study which has included a control group. Clinical examinations were conducted in 89 FL patients and 84 control farmers, matched by age, sex, and smoking habits. The mean time after the first diagnosed episode of FL was 14 yrs. The mean transfer factor of the lung for carbon monoxide (TL,CO) was on average 12% lower (p < 0.001) in FL patients compared to control farmers. In spirometry, the mean maximum expiratory flow at 50% of vital capacity (MEF50) was lower (p = 0.08) in FL patients but there were no differences in mean vital capacity (VC) or forced expiratory volume in one second (FEV1) between FL patients and control farmers. However, airway obstruction, defined as an FEV1/VC less than 88% of predicted, was more common in FL patients than in control farmers (33 versus 17%; p = 0.02). Patients who had had recurrent episodes of FL had a significantly lower mean TL,CO compared to those FL patients who had experienced only a single episode. In conclusion, impairment of the pulmonary transfer factor is the most important long-term consequence of farmer's lung. However, farmer's lung may also lead to development of airway obstruction.
The effect of low-dose inhalation of nitric oxide in patients with pulmonary fibrosis
Authors: Yoshida M , Taguchi O , Gabazza EC , Yasui H , Kobayashi T , Kobayashi H , Maruyama K , Adachi Y
Published: February 2003

The aim of this study was to determine whether low-dose inhalation of nitric oxide (NO) improves pulmonary haemodynamics and gas exchange in patients with stable idiopathic pulmonary fibrosis (IPF). The investigation included 10 IPF patients breathing spontaneously. Haemodynamic and blood gas parameters were measured under the following conditions: 1) breathing room air; 2) during inhalation of 2 parts per million (ppm) NO with room air; 3) whilst breathing O2 alone (1 L.min-1); and 4) during combined inhalation of 2 ppm NO and O2 (1 L.min-1). During inhalation of 2 ppm NO with room air the mean pulmonary arterial pressure (Ppa 25 +/- 3 vs 30 +/- 4 mmHg) and the pulmonary vascular resistance (PVR 529 +/- 80 vs 699 +/- 110 dyn.s.cm-5) were significantly (p < 0.01) lower than levels measured whilst breathing room air alone. However the arterial oxygen tension (Pa,O2) did not improve. The combined inhalation of NO and O2 produced not only a significant (p < 0.01) decrease of Ppa (23 +/- 2 vs 28 +/- 3 mmHg) but also, a remarkable improvement (p < 0.05) in Pa,O2 (14.2 +/- 1.2 vs 11.7 +/- 1.0 kPa) (107 +/- 9 vs 88 +/- 7 mmHg)) as compared with the values observed during the inhalation of O2 alone. These findings suggest that the combined use of nitric oxide and oxygen might constitute an alternative therapeutic approach for treating idiopathic pulmonary fibrosis patients with pulmonary hypertension. However, further studies must first be carried out to demonstrate the beneficial effect of oxygen therapy on pulmonary haemodynamics and prognosis in patients with idiopathic pulmonary fibrosis and to rule out the potential toxicity of inhaled nitric oxide, particularly when used in combination with oxygen.
Arterial endothelin-1 level in pulmonary emphysema and interstitial lung disease. Relation with pulmonary hypertension during exercise
Authors: Yamakami T , Taguchi O , Gabazza EC , Yoshida M , Kobayashi T , Kobayashi H , Yasui H , Ibata H , Adachi Y
Published: February 2003

This study was undertaken to assess the arterial plasma levels of endothelin-1 (ET-1) and their relationship with pulmonary haemodynamic and gas exchange variables during exercise in patients with emphysema and interstitial lung disease (ILD). Incremental cycle ergometry was performed in all patients up to maximal capacity. At rest, arterial ET-1 levels were higher in emphysema (1.86 +/- 0.35 pg.mL-1; p < 0.02) and ILD (1.75 +/- 0.25 pg.mL-1; p < 0.03) patients than in controls (1.35 +/- 0.18 pg.mL-1). Emphysema (2.08 +/- 0.26 versus 1.70 +/- 0.40 pg.mL-1) and ILD (1.98 +/- 0.21 versus 1.67 +/- 0.02 pg.mL-1) patients with pulmonary hypertension (PH) presented significantly (p < 0.05) higher arterial ET-1 levels than those without. At rest, arterial ET-1 levels were significantly correlated with mean pulmonary arterial pressure (Ppa) in both ILD (r = 0.8, p = 0.01) and emphysema (r = 0.5, p = 0.03) patients. During exercise, the arterial ET-1 levels were significantly correlated with arterial oxygen (Pa,O2) (r = -0.6, p = 0.04), alveolar-arterial oxygen difference (r = 0.8, p = 0.01), and Ppa (r = 0.6, p = 0.04) in ILD patients, but not in those with emphysema. In brief, the results of this study suggest that arterial endothelin-1 is markedly increased in interstitial lung disease and emphysema patients, and that, it is related to the exercise-induced exacerbation of pulmonary hypertension in patients with interstitial lung disease, but not in those with emphysema.
Inhibition of hypoxic pulmonary vasoconstriction in isolated rat resistance arteries by atrial natriuretic peptide
Authors: Rogers TK , Thompson JS , Morice AH
Published: February 2003

Atrial natriuretic peptide (ANP) is a vasodilator secreted by the heart in response to right atrial stretch. We have hypothesized that ANP may be released to attenuate pulmonary hypertension due to hypoxia. We have examined whether ANP inhibits hypoxic pulmonary vasoconstriction (HPV) in isolated pulmonary resistance vessels (PRV) from chronically hypoxic (CH) rats, compared to air-breathing, control (C) rats. After at least 17 days of chronic hypoxia, vessels (n = 29) were dissected from CH and C littermates and mounted in an automated myograph. The inhibitory effect of ANP on the rapid first contractile phase of HPV, and the relaxant effect of ANP on vessels tonically contracted in the second phase of HPV, were studied. ANP caused concentration-dependent inhibition of HPV in both C and CH vessels (p < 0.001), whilst vehicle had no effect (mean maximum inhibition was 88 and 101%, respectively, at 17 nM ANP). ANP also caused significant concentration-dependent relaxation of the second contractile phase of HPV, which was similar in C and CH vessels (mean maximum relaxation of 89 and 94%, respectively; median effective concentrations were 2.4 and 2.0 nM, respectively). We conclude that atrial natriuretic peptide is a potent antagonist of both contractile phases of hypoxic pulmonary vasoconstriction in isolated rat pulmonary resistance vessels at concentrations similar to those observed in hypoxic pulmonary hypertension in life. There was no difference between vessels from chronically hypoxic and control animals.
AutoSet nasal CPAP titration: constancy of pressure, compliance and effectiveness at 8 month follow-up
Authors: Teschler H , Farhat AA , Exner V , Konietzko N , Berthon-Jones M
Published: February 2003

We have previously shown that AutoSet satisfactorily improves sleep-disordered breathing and sleep architecture in subjects with obstructive sleep apnoea (OSA) syndrome. The aim of this study was to determine, in subjects treated with long-term conventional fixed pressure continuous positive airway pressure (CPAP) at the AutoSet recommended pressure, whether: the long-term compliance is satisfactory; the improvement persists once initial rebound is over; the titration pressure is stable with time; and the titration pressure is comparable with manual titration pressure using a similar end-point. Twenty males with OSA, previously studied with full polysomnography on their diagnostic night, at manual and AutoSet titration, and at the AutoSet recommended fixed pressure, were re-studied after a mean of 3 and 8 months of treatment at the recommended fixed pressure. Re-study included home respiratory monitoring (Nellcor EdenTrace), and repeated manual and AutoSet titration with polysomnography. Compliance was assessed with hour-meter readings. Mean (+/-SEM) usage was 5.7 +/- 0.1 h.night-1 at 3 and 8 months. The arousal index remained normalized. Diagnostic respiratory disturbance index (RDI) was 60.3 +/- 5.7 events.h-1. On AutoSet at fixed CPAP, RDI was initially 2.6 +/- 0.7 events.h-1, then rose slightly (p < 0.001) to 4.3 +/- 0.6 events.h-1 at 3 months, and was 3.6 +/- 0.5 events.h-1 at 8 months. AutoSet titration pressure was: 9.9 +/- 0.4 cmH2O initially, 10.6 +/- 0.4 cmH2O at 3 months, and 9.7 +/- 0.5 cmH2O at 8 months (NS). Manual titration pressure at 8 months was 10.4 +/- 0.4 cmH2O. The standard deviation of the discrepancy with AutoSet was 0.84 cmH2O. In conclusion, the AutoSet recommended pressure varies little with time, and closely predicts the final manual titration pressure; the improvement in respiratory disturbance index was largely maintained, and compliance was good, although probably enhanced by close supervision.
Right ventricular dysfunction in patients with obstructive sleep apnoea syndrome
Authors: Sanner BM , Konermann M , Sturm A , Muller HJ , Zidek W
Published: February 2003

There is conclusive evidence that obstructive sleep apnoea syndrome (OSAS) influences right heart haemodynamics and can also induce pulmonary hypertension. It is not known, however, whether right ventricular dysfunction can occur in patients with OSAS in the absence of lung disease. We studied 107 patients (94 males, 13 females, mean age 55 +/- 11 yrs) with polysomnographically verified OSAS in whom clinically significant lung disease was excluded. Right ventricular ejection fraction (RVEF) was determined by radionuclide ventriculography. In addition, pulmonary function tests, arterial blood gas analysis and right heart catheterization were performed. RVEF was impaired in 19 patients (18%). Eighteen (95%) had signs or symptoms consistent with mild right ventricular failure. Patients with or without impaired RVEF did not differ with respect to body mass index, age or lung function. Stepwise multiple logistic regression analysis revealed that RVEF was significantly associated with the apnoea/hypopnoea index (r = -0.68; p = 0.0009) and the extent of nocturnal oxyhaemoglobin saturation (r = 0.42; p = 0.035), but not with age, body mass index, blood gas analysis, gender, lung function, pulmonary artery pressure and left ventricular ejection fraction. We conclude that in patients with otherwise unexplained right ventricular failure, obstructive sleep apnoea syndrome may underlie the right ventricular dysfunction.
The effect of age, sex, obesity and posture on upper airway size
Authors: Martin SE , Mathur R , Marshall I , Douglas NJ
Published: February 2003

Most patients with sleep apnoea/hypopnoea syndrome (SAHS) are middle-aged men. As there are conflicting data on the effects of age and gender on upper airway calibre, we tested the hypothesis that increasing age and the male sex predispose to upper airway narrowing in normal subjects. We measured upper airway calibre using acoustic reflection in 60 men and 54 women (median 35, range 16-74 yrs) both seated and supine. All upper airway dimensions, except oropharyngeal junction (OPJ), decreased with increasing age in both men and women (r > -0.24, p < or = 0.05) while supine (r2 > 0.06). Men had greater changes in airway area at OPJ on lying down (mean (SEM) 0.5 (0.1), 0.2 (0.1) cm2; p < 0.02). Men had greater body mass indices (mean (SD) 26 (4), 24 (4) kg.m-2; p = 0.04), and larger neck circumferences (mean (SD) 38 (3), 33 (2) cm; p < 0.0001) than women. For any body mass index, neck circumference was larger in men than women (p < 0.001). This study shows that upper airway size decreases with increasing age in both men and women, and that men have greater upper airway collapsibility on lying down at oropharyngeal junction than women.
Water vapour and carbon dioxide decrease nitric oxide readings
Authors: van der Mark TW , Kort E , Meijer RJ , Postma DS , Koeter GH
Published: February 2003

Measurement of nitric oxide levels in exhaled air is commonly performed using a chemiluminescence detector. However, water vapour and carbon dioxide affect the chemiluminescence process. The influence of these gases at the concentrations present in exhaled air, has not yet been studied. For this in vitro study, mixtures of 50, 100 and 200 parts per billion (ppb) NO in air were prepared and fed into the NO analyser either directly or bubbled through water. Mixtures with CO2 were prepared by adding 0-10% CO2 to the diluent air. We found a significant decrease in NO readings in the water-saturated samples compared to the dry gas (p < 0.001), strongly dependent on the partial pressure of water. NO levels in exhaled air (mean 10 +/- 2 ppb) showed a decrease of 17 +/- 3% when water vapour was not absorbed. From the experiments with CO2 we found a decrease in NO reading of 1.04 +/- 0.07% per volume CO2 (%). Presence of water vapour, thus, leads to a systematic underestimation of NO levels. Insertion of a water absorber might, therefore, be advantageous. The influence of CO2 concentrations in the normal respiratory range is negligible. With high expiratory CO2 levels as applied in permissive hypercapnia, the effects may be substantial.
Airway epithelium as an effector of inflammation: molecular regulation of secondary mediators
Authors: Martin LD , Rochelle LG , Fischer BM , Krunkosky TM , Adler KB
Published: February 2003

Deleterious environmental stimuli cause the airway epithelium to respond with increased secretions of mucus, reaction of oxygen/nitrogen species, changes in ciliary beating, and the influx of inflammatory cells. The epithelium is a target for factors released by infiltrating inflammatory cells, and has recently been shown to serve as an effector of such inflammation. Molecular mechanisms regulating production of secondary inflammatory mediators (cytokines, lipid mediators, and reactive oxygen/nitrogen species) have yet to be fully described. This report reviews the production of secondary mediators by epithelial cells and by airway epithelium. Lipid mediators are enzymatically produced by the airway epithelium in response to primary mediators. Molecular mechanisms regulating the production of cyclo-oxygenase, lipoxygenase and prostaglandin synthase are discussed, along with the potential of lipid mediators to produce inflammation. The molecular regulation of nitric oxide production is also described in the context of its role as a signalling molecule in pathways regulating secretion of mucus, ciliary motion, and intercellular adhesion molecule-1 (ICAM-1) expression. The production of cytokines by the airway epithelium is shown to play a role in causing inflammation associated with respiratory diseases. Particular attention is paid to molecular mechanisms governing the expression of tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-8 (IL-8).
When Translation Meets Metabolism: Multiple Links to Diabetes
Authors: Shi Yuguang , Taylor Simeon I. , Tan Seng-Lai , Sonenberg Nahum
Published: February 2003

Type 2 diabetes is a polygenic disorder characterized by multiple biochemical defects including transcriptional, translational, and posttranslational abnormalities. Although major progress has been made in elucidation of factors at the transcriptional and posttranslational levels, defects at the translational level remain elusive. Mutation of a kinase that regulates translation initiation has been implicated in the etiology of a monogenic form of diabetes known as Wolcott-Rallison syndrome. Characterization of mice rendered deficient in eukaryotic initiation factors has provided model systems to study the involvement of translation in regulating insulin synthesis and secretion, hepatic function, peripheral insulin resistance, and diabetic complications. Recent progress in the understanding of endoplasmic reticulum overload by unfolded proteins has begun to uncover mechanisms leading to pancreatic β-cell exhaustion. Future advances in this area may lead to identification of the missing links in the pathogenesis of β-cell failures due to conditions such as hyperinsulinemia, hyperglycemia, and long-term treatment with sulfonylureas, and thus may identify novel therapeutic targets for diabetes.
Endothelin 1-mediated regulation of pharyngeal bone development in zebrafish
Authors: Kimmel Charles B. , Ullmann Bonnie , Walker Macie , Miller Craig T. , Crump Justin G.
Published: February 2003

Endothelin 1 (Edn1), a secreted peptide expressed ventrally in the primordia of the zebrafish pharyngeal arches, is required for correct patterning of pharyngeal cartilage development. We have studied mutants and morpholino-injected larvae to examine the role of the Edn1 signal in patterning anterior pharyngeal arch bone development during the first week after fertilization. We observe a remarkable variety of phenotypic changes in dermal bones of the anterior arches after Edn1 reduction, including loss, size reduction and expansion, fusion and shape change. Notably, the changes that occur appear to relate to the level of residual Edn1. Mandibular arch dermal bone fusions occur with severe Edn1 loss. In the dorsal hyoid arch, the dermal opercle bone is usually absent when Edn1 is severely reduced and is usually enlarged when Edn1 is only mildly reduced, suggesting that the same signal can act both positively and negatively in controlling development of a single bone. Position also appears to influence the changes: a branchiostegal ray, a dermal hyoid bone normally ventral to the opercle, can be missing in the same arch where the opercle is enlarged. We propose that Edn1 acts as a morphogen;different levels pattern specific positions, shapes and sizes of bones along the dorso-ventral axis. Changes involving Edn1 may have occurred during actinopterygian evolution to produce the efficient gill-pumping opercular apparatus of teleosts.
Twoendothelin 1effectors,hand2andbapx1,pattern ventral pharyngeal cartilage and the jaw joint
Authors: Miller Craig T. , Yelon Deborah , Stainier Didier Y. R. , Kimmel Charles B.
Published: February 2003

A conserved endothelin 1 signaling pathway patterns the jaw and other pharyngeal skeletal elements in mice, chicks and zebrafish. In zebrafish,endothelin 1 (edn1 or sucker) is required for formation of ventral cartilages and joints in the anterior pharyngeal arches of young larvae. Here we present genetic analyses in the zebrafish of twoedn1 downstream targets, the bHLH transcription factor Hand2 and the homeobox transcription factor Bapx1, that mediate dorsoventral (DV) patterning in the anterior pharyngeal arches.

First we show that edn1-expressing cells in the first (mandibular)and second (hyoid) pharyngeal arch primordia are located most ventrally and surrounded by hand2-expressing cells. Next we show that along the DV axis of the early first arch primordia, bapx1 is expressed in an intermediate domain, which later marks the jaw joint, and this expression requires edn1 function. bapx1 function is required for formation of the jaw joint, the joint-associated retroarticular process of Meckel's cartilage, and the retroarticular bone. Jaw joint expression ofchd and gdf5 also requires bapx1 function.

Similar to edn1, hand2 is required for ventral pharyngeal cartilage formation. However, the early ventral arch edn1-dependent expression of five genes (dlx3, EphA3, gsc, msxe and msxb)are all present in hand2 mutants. Further, msxe andmsxb are upregulated in hand2 mutant ventral arches. Slightly later, an edn1-dependent ventral first arch expression domain of gsc is absent in hand2 mutants, providing a common downstream target of edn1 and hand2. In hand2mutants, bapx1 expression is present at the joint region, and expanded ventrally. In addition, expression of eng2, normally restricted to first arch dorsal mesoderm, expands ventrally in hand2and edn1 mutants. Thus, ventral pharyngeal specification involves repression of dorsal and intermediate (joint region) fates. Together our results reveal two critical edn1 effectors that pattern the vertebrate jaw: hand2 specifies ventral pharyngeal cartilage of the lower jaw and bapx1 specifies the jaw joint.
Cell fate specification and competence by Coco, a maternal BMP, TGFβand Wnt inhibitor
Authors: Bell Esther , Muñoz-Sanjuán Ignacio , Altmann Curtis R. , Vonica Alin , Brivanlou Ali H.
Published: February 2003

Patterning of the pre-gastrula embryo and subsequent neural induction post-gastrulation are very complex and intricate processes of which little,until recently, has been understood. The earliest decision in neural development, the choice between epidermal or neural fates, is regulated by bone morphogenetic protein (BMP) signaling within the ectoderm. Inhibition of BMP signaling is sufficient for neural induction. Many secreted BMP inhibitors are expressed exclusively within the organizer of the Xenopusgastrula embryo and therefore are predicted to act as bona fide endogenous neural inducers. Other cell-autonomous inhibitors of the BMP pathway are more widely expressed, such as the inhibitory Smads, Smad6 and Smad7. In this report we describe the biological and biochemical characterization of 51-B6, a novel member of Cerberus/Dan family of secreted BMP inhibitors, which we identified in a screen for Smad7-induced genes. This gene is expressed maternally in an animal to vegetal gradient, and its expression levels decline rapidly following gastrulation. In contrast to known BMP inhibitors, 51-B6 is broadly expressed in the ectoderm until the end of gastrulation. The timing,pattern of expression, and activities of this gene makes it unique when compared to other BMP/TGFβ/Wnt secreted inhibitors which are expressed only zygotically and maintained post-gastrulation. We propose that a function of 51-B6 is to block BMP and TGFβ signals in the ectoderm in order to regulate cell fate specification and competence prior to the onset of neural induction. In addition, we demonstrate that 51-B6 can act as a neural inducer and induce ectopic head-like structures in neurula staged embryos. Because of this embryological activity, we have renamed this clone Coco, after the Spanish word meaning head.
Boundary element analysis of finite domains under thermal and mechanical shock with the Lord-Shulman theory
Authors: Hosseini-Tehrani P , Eslami M. R
Published: February 2003

A boundary element method based on the Laplace transform technique is developed for transient coupled thermoelasticity problems with relaxation times in a two-dimensional finite domain. The dynamic thermoelastic model of Lord and Shulman (LS) is selected to show how mechanical and thermal energy conversion takes place in a coupled field. The Laplace transform method is applied to the time domain and the resulting equations in the transformed field are discretized using the boundary element method. The nodal dimensionless temperature and displacements in the transformed domain are inverted to obtain the actual physical quantities, using the numerical inversion of the Laplace transform method. The creation and propagation of elastic and thermoelastic waves in a finite domain and their effects on each other are investigated for the first time in this paper. Different relaxation times are chosen to show briefly the events that take place in temperature, displacement and stress fields considering the LS theory. Details of the formulation and numerical implementation are presented.
Value Change in Oil and Gas Production: V. Incorporation of Uncertainties and Determination of Relative Importance
Authors: Lerche I. , Noeth S.
Published: February 2003

The influence of two fundamentally different types of uncertainty on the value of oil field production are investigated here. First considered is the uncertainty caused by the fact that the expected value estimate is not one of the possible outcomes. To correctly allow for the risk attendant upon using the expected value as a measure of worth, even with statistically sharp parameters, one needs to incorporate the uncertainty of the expected value. Using a simple example we show how such incorporation allows for a clear determination of the relative risk of projects that may have the same expected value but very different risks. We also show how each project can be risked on its own using the expected value and variance. This uncertainty type is due to the possible pathways for different outcomes even when parameters categorizing the system are taken to be known. Second considered is the risk due to the fact that parameters in oil field estimates are just estimates and, as such, have their own intrinsic errors that influence the possible outcomes and make them less certain. This sort of risk depends upon the uncertainty of each parameter, and also the type of distribution the parameters are taken to be drawn from. In addition, not all uncertainties in parameter values are of equal importance in influencing an outcome probability. We show how can determine the relative importance for the parameters and so determine where to place effort to resolve the dominant contributions to risk if it is possible to do so. Considerations of whether to acquire new information, and also whether to undertake further studies under such an uncertain environment, are used as vehicles to address these concerns of risk due to uncertainty. In general, an oil filed development project has to contend with all the above types of risk and uncertainty. It is therefore of importance to have quantitative measures of risk so that one can compare and contrast the various effects, and so that corporate decision-makers can use the information in a rational manner as they seek to enhance corporate profit. This paper provides such methods and measures of assessing risk.
Energy Conservation and Storage Systems
Authors: Demirbaş Ayhan
Published: February 2003

In response to increasing electrical energy costs and the desire for better lad management, thermal storage technology has recently been developed. Storage of thermal energy in the form of sensible and latent heat has become an important aspect of energy management with the emphasis on efficient use and conservation of the waste heat and solar energy in industry and buildings. Thermal storage has been characterized as a kind of thermal battery.
Dynamic Modelling of Wind Farm Grid Interaction
Authors: Hansen Anca D. , Sørensen Poul , Blaabjerg Frede , Becho John
Published: February 2003

This paper describes a dynamic model of a wind farm and its nearest utility grid. It is intended to use this model in studies addressing the dynamic interaction between a wind farm and a power system, both during normal operation of the wind farm and during transient grid fault events. The model comprises the substation where the wind farm is connected, the internal power collection system of the wind farm, the electrical, mechanical and aerodynamic models for the wind turbines, and a wind model. The integrated model is built to enable the assessment of power quality and control strategies. It is implemented in the commercial dedicated power system simulation tool DIgSILENT.