bluuebunny/crossref_metadata_2025 huggingface dataset:
Baseline ventilatory function predicts the development of higher levels of fasting insulin and fasting insulin resistance index: the Normative Aging Study
Authors: Lazarus R , Sparrow D , Weiss ST
Published: November 2002

A consistent but as yet unexplained association between baseline ventilatory function and risk of coronary heart disease (CHD) has been reported from many prospective studies. Insulin-resistant states are associated with increased risk of CHD. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and maximal mid-expiratory flow rate (MMEF) at study entry were examined as predictors for indirect measures of insulin resistance after a mean follow-up interval of 20.9 yrs in 1050 nondiabetic male subjects in the Normative Aging Study. Males in the top quintile of insulin or fasting insulin resistance index (FIRI) levels at follow-up were defined as being relatively insulin resistant. FVC was negatively associated with risk of being relatively insulin resistant using the insulin (p=0.002) or FIRI (p=0.0001) criteria at follow-up in logistic regression models adjusting for baseline age, body mass index, fat distribution pattern and cigarette smoking. Similar associations were found for FEV1 and MMEF. Additional adjustment for baseline postcarbohydrate challenge glucose levels made little difference to the results, suggesting that baseline glucose intolerance was not a significant source of bias. These findings are consistent with the possibility that insulin resistance may be one of the factors mediating the previously unexplained prospective association between impairment of ventilatory function and risk of mortality from coronary heart disease.
Value of beat-to-beat blood pressure changes, detected by pulse transit time, in the management of the obstructive sleep apnoea/hypopnoea syndrome
Authors: Pitson DJ , Stradling
Published: November 2002

Two important aspects of a respiratory sleep study are a measure of inspiratory effort and an estimate of the number of arousals. These can be derived from an indirect estimate of beat-to-beat blood pressure (BP), pulse transit time (PTT). This study investigated the reproducibility of inspiratory BP falls (reflecting inspiratory effort), and BP arousals derived from PTT, and the contribution they could make to the management of the obstructive sleep apnoea/hypopnoea syndrome (OSAHS). Overnight PTT was recorded at home in 40 patients being investigated for OSAHS, and a second PTT recording was made in the sleep laboratory with full polysomnography. Patients were divided into three groups according to the severity of their sleep disorder, and a third PTT recording was made at home in 13 patients subsequently established on nasal continuous positive airway pressure (CPAP). The reproducibility between the home and laboratory studies was reasonable (r=0.87 for inspiratory BP falls, r=0.81 for BP arousals). Both derivatives showed a clear progression through the three patient groups, which returned to normal on treatment. The differences between the groups were significant (p<0.001 for inspiratory BP falls, p=0.0014 for BP arousals). Receiver operator characteristic curves, used to compare polysomnography variables and PTT variables, confirmed that the PTT variables were as good as apnoea-hypopnoea index (AHI), >4% arterial oxygen saturation dip rate and electroencephalography micro-arousals at dividing patients into two groups, either requiring nasal CPAP or not requiring CPAP. Pulse transit time can provide a noninvasive estimate of inspiratory effort and a measure of arousals that together document disease severity and response to treatment and may be useful in managing obstructive sleep apnoea/hypopnoea syndrome.
Maximum rate of change in oesophageal pressure assessed from unoccluded breaths: an option where mouth occlusion pressure is impractical
Authors: Hamnegard CH , Polkey MI , Kyroussis D , Mills GH , Green M , Bake B , Moxham J
Published: November 2002

The mouth occlusion pressure 100 ms after onset of inspiration (P0.1) is considered a clinically useful measure of the combined output of the respiratory centre and muscle pump. However, theoretical and practical difficulties can arise when using P0.1 in the assessment of patients with severe chronic obstructive pulmonary disease (COPD). It was hypothesized that the maximum rate of change in oesophageal pressure (dPoes,max/dt) may be an alternative to P0.1. To test this hypothesis P0.1 was compared with mean dPoes,max/dt measured from neighbouring unoccluded breaths in five normal subjects during CO2 rebreathing. In all subjects a close correlation was found between both dPoes,max/dt and P0.1 and carbon dioxide tension (PCO2). In six patients with severe COPD performing exhaustive treadmill walks, dPoes,max/dt was found to increase progressively with walking time. Mean dPoes,max/dt at the start was 6.2 cmH2O x 100 ms(-1) and at the finish was 18.7 cmH2O x 100 ms(-1) (p<0.03). In conclusion, the maximum rate of change in oesophageal pressure measured from unoccluded breaths could be an alternative in circumstances where it is not feasible to use measurements of the mouth occlusion pressure 100 ms after onset of inspiration.
Respiratory bronchiolitis in smokers with spontaneous pneumothorax
Authors: Cottin V , Streichenberger N , Gamondes JP , Thevenet F , Loire R , Cordier JF
Published: November 2002

Respiratory bronchiolitis (RB) is defined by the accumulation of pigmented macrophages in the lumen and wall of respiratory and membranous bronchioles of smokers. The aim of this study was to determine whether spontaneous pneumothorax was associated with a high prevalence of RB. Seventy-nine consecutive patients who underwent a surgical procedure (thoracotomy or thoracoscopy) for recurrence or persistence of primary spontaneous pneumothorax despite thoracic drainage were studied retrospectively. RB was found in 70 of 79 (88.6%) smokers operated for spontaneous pneumothorax. Associated interstitial pathological abnormalities were present in 53 of 79 cases (67.1%). In nine patients, the pathological lesions were severe and resembled desquamative interstitial pneumonia. Emphysematous lesions were present in about one-third of the patients. Although the possible pathophysiological consequences of respiratory bronchiolitis remain speculative, this study demonstrates the high prevalence of this pathological abnormality in patients with pneumothorax requiring surgical treatment.
Many faces of pulmonary aspergillosis
Authors: Sharma OP , Chwogule R
Published: November 2002

Aspergillus is a ubiquitous fungus. It is commonly isolated as an upper respiratory tract saprophyte and is the most frequent contaminant in laboratory specimens. Because species of aspergillus are omnipresent, one must be cautious in ascribing a causal role to the fungus obtained from patients. Aspergillus has low pathogenicity for humans and animals and rarely invades the immunologically competent host. Although the fungus can affect any organ system, the respiratory tract is involved in >90% of afflicted patients. Pulmonary aspergillosis, depending whether the host is atopic or immunosuppressed, may be classified under four categories: allergic or hypersensitivity syndromes, saprophytic colonization, invasive (infective) dissemination, and chemical or toxic pneumonitis. These entities differ clinically, radiologically, immunologically, and in their response to various therapeutic agents. An increased awareness, an aggressive approach to securing the diagnosis, and instituting early and appropriate therapy are needed to reduce the high morbidity and mortality caused by many of the aspergillus-related syndromes.
Deep breathing and awake apnoea in a patient who had recurrent hypoxaemia and hypercapnia without sleep apnoea
Authors: Chin K , Oku Y , Nishimura K , Ohi M
Published: November 2002

A 21 yr old with deep breathing and awake apnoea, who had recurrent hypoxaemia and hypercapnia without sleep apnoea, was presented. Although the organic abnormality responsible for the breathing disturbance was not found, administration of acetazolamide facilitated several breaths between sighs, and the patient's hypoxaemia with hypercapnia improved. Some patients who have abnormalities in the cortical control of breathing that cannot be detected by present methods of examination may experience some improvement in breathing with the administration of chemical stimulants such as acetazolamide.
Micronodules and emphysema in coal mine dust or silica exposure: relation with lung function
Authors: Gevenois PA , Sergent G , De Maertelaer V , Gouat F , Yernault JC , De Vuyst P
Published: November 2002

The aim of this study was to investigate the respective effects of micronodules and pulmonary emphysema, detected by computed tomography (CT), on lung function in workers exposed to silica and coal mine dust. Eighty-three subjects exposed to silica (n=35) or to coal mine dust (n=48), without progressive massive fibrosis, were investigated by high-resolution and conventional CT scans to detect micronodules and to quantify pulmonary emphysema by measuring the relative area of the lung with attenuation values lower than -950 Hounsfield units. Sixty-six (54.5%) subjects had evidence of micronodules on CT scans. Smokers had micronodules more rarely than nonsmokers. Significant correlations were found between the forced expiratory volume in one second (FEV(1); % predicted) (r=-0.41, p<0.001), FEV1/vital capacity (VC) (r=-0.61, p<0.001), diffusing capacity of the lung for carbon monoxide (DL,CO) (r=-0.36, p<0.001) and the extent of emphysema. No difference was demonstrated in the linear relationships between the extent of emphysema and the pulmonary function according to the type of exposure or the presence of micronodules on CT scans. This study suggests that micronodules detected by computed tomography have no influence, by themselves, on pulmonary function and that they should only be considered as a marker of exposure.
Effect of a novel PACAP-27 analogue on muscarinic airway responsiveness in guinea-pigs in vivo
Authors: Okazawa A , Cui ZH , Lotvall J , Yoshihara S , Skoogh BE , Kashimoto K , Linden A
Published: November 2002

A recent study showed that the novel pituitary adenylate cyclase-activating peptide (PACAP)-27 analogue [Arg15,20,21,Leu17]-PACAP-27-Gly-Lys-Arg-NH2 causes sustained airway smooth muscle relaxation in vitro. This study examined whether this analogue also has bronchoprotective effects, by inhibiting muscarinic airway responsiveness in vivo. Total lung resistance was measured in anaesthetized, tracheostomized and ventilated guinea-pigs. Increasing doses of acetylcholine were given i.v. once before and thereafter repeatedly each hour after intratracheal instillation of either the PACAP-27 analogue or the clinical beta2-agonist bronchodilator salbutamol. Mean arterial blood pressure (MAP) was monitored to detect cardiovascular side-effects. Both the PACAP-27 analogue and salbutamol significantly attenuated the airway responsiveness to acetylcholine. The total inhibitory effect of the PACAP-27 analogue (350 nmol) corresponded to that of salbutamol (35 nmol). The inhibitory effect of salbutamol (35 nmol) peaked during the second hour and disappeared prior to 5 h after administration. In contrast, the corresponding effect of the analogue (350 nmol) gradually increased and peaked during the fifth hour after administration, whereas it did not fade during the observation period. Both the PACAP-27 analogue (350 nmol) and salbutamol (35 nmol) produced a transient decrease in MAP within 6 min after administration. In conclusion, the novel pituitary adenylate cyclase-activating peptide-27 analogue has bronchoprotective properties, by decreasing muscarinic airway responsiveness in guinea pigs in vivo. The time course of its effect is compatible with a more sustained duration of action compared with salbutamol.
Neutrophil chemokines in bronchoalveolar lavage fluid and leukocyte-conditioned medium from nonsmokers and smokers
Authors: Morrison D , Strieter RM , Donnelly SC , Burdick MD , Kunkel SL , MacNee W
Published: November 2002

Polymorphonuclear neutrophils (PMN) have been implicated in the pathogenesis of emphysema. The chemokines interleukin-8(IL-8), growth-related oncogene (GRO-alpha) and extractable nuclear antigen (ENA)-78 may be involved in the increased numbers of PMN in smokers' airspaces. The levels of these cytokines in bronchoalveolar lavage fluid (BALF) and bronchoalveolar lavage leukocyte conditioned medium (LCM), along with BALF PMN numbers in 12 smokers who abstained for 12 h (chronic smoking) or continued to smoke until I h before study (acute smoking) and seven nonsmokers were compared. Neutrophils in BALF increased in acute (1.96+/-0.53%, 0.99+/-0.32x10(6) cells) compared with chronic smokers (0.59+/-0.25%, 0.61+/-0.24x10(6) cells, p<0.05 nonsmokers) and nonsmokers (0.79+/-0.29%, 0.05+/-0.01x 10(6) cells, p<0.05). There were no differences in IL-8 or GRO-alpha in BALF between smokers and nonsmokers. ENA-78 levels were lower in smokers (p=0.006). There was no difference in IL-8, GRO-alpha or ENA-78 in LCM from unstimulated cells in smokers versus nonsmokers. After stimulation with lipopolysaccharide (LPS) 10 ng mL(-1), IL-8 release in acute smokers (p=0.04) and GRO-alpha release in smokers (p=0.009) were significantly higher than in nonsmokers. Following stimulation with LPS 100 ng.mL(-1), GRO-alpha release was higher in smokers (p=0.03) and increased further in acute smokers (p=0.02 versus nonsmokers, p=0.04 versus chronic smokers) and ENA-78 release increased in smokers (p=0.02 versus non-smokers). In conclusion, influx of polymorphonuclear neutrophils into smokers' airspaces is an acute phenomenon and neutrophil chemokine release from mixed bronchoalveolar lavage leukocytes is influenced by cigarette smoking and endotoxins.
Age-dependent inaccuracy of asthma death certification in Northern England, 1991-1992
Authors: Reid DW , Hendrick VJ , Aitken TC , Berrill WT , Stenton SC , Hendrick DJ
Published: November 2002

Asthma mortality appeared to increase two-fold in the UK from the mid- 1970s to the early 1990s, but there is evidence of inaccuracy in asthma death certification and so a region-wide investigation was undertaken to assess whether this recorded statistical trend might have been partly or wholly artefactual. A total of 35 respiratory physicians, distributed in panels of three, systemically reviewed the hospital and general practice records of 210 subjects with physician-diagnosed asthma who died in 1991 and 1992. The death certificates indicated that asthma was considered to be the primary cause of death in 103 (group 1), a contributory cause in 70 (group 2) and not relevant in 37 (group 3). There was agreement within the panels that 43% of the subjects had probably never suffered from asthma. Discordance between the panels and the certifying physicians over the correct death certification category was high for group 1 (45% for those aged <65 yrs, 75% for those aged > or =65 yrs and 64% overall) and group 2 (67%), but much less for group 3 (22%). This study concludes that asthma death certification provides a markedly inaccurate picture of asthma mortality, particularly in elderly subjects. Thus, it is speculated that if the magnitude of this source of inaccuracy has increased over the last two decades, the apparent recent increase in asthma mortality may be largely artefactual.
Clinical efficacy of low-dose inhaled budesonide once or twice daily in children with mild asthma not previously treated with steroids
Authors: Jonasson G , Carlsen KH , Blomqvist P
Published: November 2002

The aim of the present study was to examine the efficacy of low-dose inhaled budesonide (BUD) administered via Turbuhaler once or twice daily on symptoms, lung function and bronchial hyperreactivity in children with mild asthma. One hundred and sixty-three children (mean age 9.9 yrs, 56 females/107 males) with mild asthma (forced expiratory volume in one second (FEV1) 103% of predicted, morning peak expiratory flow (PEF) 87% pred, reversibility in FEV1 3%, fall in FEV1 after exercise 10.4% from pre-exercise value) and not previously treated with inhaled steroids, were included in a double-blind, randomized, parallel-group study. After a two-week run-in period, the children received inhaled BUD 100 microg or 200 microg once daily in the morning, 100 microg twice daily or placebo for 12 weeks. Exercise and methacholine challenges were performed before and at the end of treatment. After 12 weeks of therapy, the fall in FEV1 after an exercise test was significantly less in all three BUD groups (43-5.1%) than in the placebo group (8.6%). Bronchial hyperreactivity to methacholine with the provocative dose causing a 20% fall in FEV1 decreased significantly in the BUD 100 microg twice-daily group compared with placebo (ratio at the end of treatment 156%). Changes in baseline lung function (FEV1 and PEF) were less marked than changes in bronchial responsiveness. In conclusion, low doses of inhaled budesonide, given once or twice daily, provided protection against exercise-induced bronchoconstriction in children with mild asthma and near normal lung function.
Alveolar lining fluid regulates mononuclear phagocyte 5-lipoxygenase metabolism
Authors: Phare SM , Peters-Golden M , Coffey MJ
Published: November 2002

The enzyme 5-lipoxygenase (5-LO) catalyses the synthesis of leukotrienes (LT), which are important in phagocytosis and killing of microorganisms. The alveolar macrophage (AM), the primary resident defender of the alveolar space, has a greater capacity for LT synthesis than its precursor, the peripheral blood monocyte (PBM). This study investigated whether the alveolar lining fluid (ALF) upregulates LT synthetic capacity in mononuclear phagocytes. Rat AM, peritoneal macrophages (PM) and ALF were obtained by lavage from pathogen-free animals. Human PBM were isolated from normal subjects. 5-LO metabolism and expression were measured with and without ALF. Rat ALF increased 5-LO metabolism (136.4+/-15.1% of control) in cultured PBM. This was associated with increased 5-LO activating protein (FLAP) (357+/-29.5 %), and 5-LO expression (188+/-31.3%). Culture of AM for 3 days resulted in a greater decrement in LTB4 synthesis (LTB4 15.4+/-6.9% of day 1) than in PM (54.7+/-8.3% of day 1), suggesting a greater dependence of AM 5-LO metabolism on ALF. 5-LO and FLAP expression decreased to a greater degree in AM than PM in culture. Furthermore, AM cultured with ALF maintained their LT synthetic capacity, FLAP and 5-LO expression compared with control cells cultured in medium alone. In conclusion, alveolar lining fluid increased 5-lipoxygenase metabolism in peripheral blood monocytes and maintained it in cultured alveolar macrophages, by a mechanism of increased 5-lipoxygenase and 5-lipoxygenase activating protein expression. This may boost host defence capabilities.
The relationship between cardiac output and posthyperventilation hyperpnoea in patients with essential hypertension
Authors: Bellofiore S , Malatino LS , Sapienza MA , Bellanuova I , Cataliotti A , Di Maria GU
Published: November 2002

Posthyperventilation hyperpnoea (PHVH) is the progressive decline in minute ventilation (V'E) that follows abrupt cessation of voluntary hyperventilation. It has been hypothesized that the increase in cardiac output (CO) during hyperventilation could contribute to the duration of PHVH. This hypothesis was tested by measuring the duration of PHVH in patients with essential hypertension, in whom the increase in CO as a result of various stimuli is less pronounced. Twenty male hypertensives (mean arterial blood pressure+/-SEM: 178/ 107+/-3/1 mmHg), and 12 age-matched male healthy subjects were studied. The study consisted of three periods: control (5 min), voluntary hyperventilation (2 min), and recovery (3 min). V'E, CO, end-tidal CO2 and O2 tensions were measured, and the time constant (tau) of the V'E decay during recovery calculated. The V'E decay was faster in hypertensives (tau: 0-8.4 s) than in healthy subjects (tau: 12-59 s; p<0.01). During voluntary hyperventilation, CO increased to a lesser extent in hypertensives (6.8+0.7 L.min(-1)) than in healthy subjects (12.9+/-1.1 L.min(-1); p<0.01). In hypertensives, changes in CO during voluntary hyperventilation were significantly related to tau (r=0.646; n=20; p=0.002). The less pronounced rise in cardiac output during hyperventilation in hypertensives could account for the shorter duration of posthyperventilation hyperpnoea.
Factor V Leiden is not common in patients diagnosed with primary pulmonary hypertension
Authors: Elliott CG , Leppert MF , Alexander GJ , Ward K , Nelson L , Pietra GG
Published: November 2002

Substantial evidence suggests that thrombosis contributes to the pathogenesis of primary pulmonary hypertension (PPH). An abnormal factor V (factor V Leiden) may contribute to thrombosis in the pulmonary microcirculation of PPH patients. A point mutation in which adenine is substituted for guanine at nucleotide 1691 (1691A) alters factor V so that it resists cleavage by activated protein C. Heterozygosity for the 1691A mutation is more common (2-8%) in Caucasian Europeans and Americans than in Africans (1%) and Asians (<1%). The aim of the study was to examine the prevalence of the mutation that codes for factor V Leiden in individuals with PPH. We identified 42 Caucasians diagnosed with PPH. We extracted deoxyribonucleic acid (DNA) from whole blood and assayed DNA samples for the point mutation (1691 A) that codes for factor V Leiden. One out of 42 (2.4%; 95% confidence interval=0.1-12.6) Caucasians diagnosed with PPH was heterozygous for the normal 1691G and mutant 1691A allele. All 10 individuals with familial PPH were homozygous for the normal 1691G allele. The prevalence of heterozygosity for the 1691A allele and the normal 1691G allele does not differ from that observed in reference (control) populations. The low prevalence of the 1691A mutation among individuals diagnosed with primary pulmonary hypertension provides evidence that factor V Leiden does not contribute to the pathogenesis of the disease in most patients.
Measuring tidal volume and functional residual capacity change in sleeping infants using a volume displacement plethysmograph
Authors: Wilson SJ , O'Brien C , Harris MA , Masters IB
Published: November 2002

The noninvasive measurement of infant lung function during unsedated sleep in infants has been a long-standing objective in paediatric respiratory medicine. This note reports on the design and performance of a head-out volume-displacement plethysmograph (VDP) that overcomes some of the limitations of traditional lung function apparatus. The VDP comprises a rigid acrylic box with an integral water-sealed spirometer and a novel neck seal. The bilayer neck seal is of variable compliance and is comfortable and simple to use. The spirometer permits volume resolution of 1.5 mL and a dynamic range in excess of 100 mL. The frequency response extends from 0-7 Hz. Spirometer inertance was measured as 0.0015 kPa.L(-1).s(-2), resistance 0.021 kPa.L(-1).s(-1) and box capacitance 0.18L.kPa(-1). Tidal volume, respiratory rate and changes in functional residual capacity can be recorded during unsedated rapid eye movement and nonrapid eye movement whilst monitoring with conventional polysomnographic methods. The head-out configuration allows additional instrumentation to be implemented with ease, avoids facial stimulation and allows unimpeded access to the upper airway. A polysomnograph illustrating the limitations of respiratory inductance plethysmography signals and typical changes in functional residual capacity are shown.
Seasonal clustering of sarcoidosis presenting with erythema nodosum
Authors: Wilsher ML
Published: November 2002

Seasonal clustering of sarcoidosis presenting with erythema nodosum (EN) has previously been reported only in the northern hemisphere. Of 59 patients presenting to a single centre in New Zealand with a new diagnosis of sarcoidosis, 21 had EN and three more had acute arthralgia without EN. These patients were compared with the rest of the cohort. The patients with EN or arthralgia alone presented exclusively between April and December, with peak clustering in the spring months of August, September and October (p<0.001, Fisher's exact test). This cohort was more likely to have a stage I chest radiograph and to be female (p<0.05), but there were no other differences between the groups. This is the first report of seasonal clustering in the southern hemisphere suggesting a common environmental trigger in the aetiology of sarcoidosis.
Difficult asthma
Authors: Barnes PJ , Woolcock AJ
Published: November 2002

Asthma is usually easy to manage, but approximately 5% of patients are not controlled even on high doses of inhaled corticosteroids. It is important to assess these patients carefully in order to identify whether there are any correctable factors that may contribute to their poor control. It is critical to make a diagnosis of asthma and to exclude other airway diseases, particularly chronic obstructive pulmonary disease (COPD), and vocal cord dysfunction ("pseudo-asthma"). Poor adherence to therapy, particularly inhaled corticosteroids, is a common reason for a poor response. There may be unidentified exacerbating factors, including unrecognized allergens, occupational sensitizers, dietary additives, drugs, gastro-oesophageal reflux, upper airway disease, or other systemic diseases, that need to be identified and avoided or treated. Psychological factors may be important in some patients, but it is difficult to know whether these are causal or secondary to troublesome disease. Some patients have instability of their asthma, with resistant nocturnal asthma, premenstrual exacerbations or chaotic and unpredictable instability (brittle asthma). A few patients are completely resistant to corticosteroids, but more patients are relatively resistant and require relatively high doses of corticosteroids to control their symptoms (steroid-dependent). Some patients develop progressive loss of lung function, as in patients with COPD. Management of patients with difficult asthma should be supervised by a respiratory specialist and should involve careful assessment to confirm a diagnosis of asthma, identification and treatment of exacerbating factors, particularly allergens, and recording of peak expiratory flow patterns. A period of hospital admission may be the best way to assess and manage these patients. Treatment involves optimizing corticosteroids therapy, assessing additional controllers such as long-acting inhaled or subcutaneous beta2-agonists or subcutaneous, theophylline and antileukotrienes. In some patients, the use of immunosuppressive treatments may reduce steroid requirements, although these treatments are rarely effective and have side-effects. In the future, the nonsteroid anti-inflammatory treatments now in development may be useful in these patients.
Fibrous pleural tumour producing 171 litres of transudate
Authors: Ulrik CS , Viskum K
Published: November 2002

Localized fibrous tumours of the pleura (or localized benign mesothelioma) are rare, and in most cases, asymptomatic. This report describes a 48 yr old female with a right-sided fibrous pleural tumour, which produced 171 L of transudate before a correct diagnosis was reached. The tumour was surgically removed and the transudation stopped immediately.
Using the Two-Hybrid Screen in the Classroom Laboratory
Authors: Odom Daniel P. , Grossel Martha J.
Published: November 2002

The National Science Foundation and others have made compelling arguments that research be incorporated into the learning of undergraduates. In response to these arguments, a two-hybrid research project was incorporated into a molecular biology course that contained both a lecture section and a laboratory section. The course was designed around specific goals for educational outcomes, including introducing research to a wide range of students, teaching students experimental design and data analysis, and enhancing understanding of course material. Additional goals included teaching students to search genomic databases, to access scientific articles, and to write a paper in scientific format. Graded events tested these goals, and a student evaluation indicated student perception of the project. According to our analysis of the data, the yeast two-hybrid screen was a success: several novel clones were identified; students met expectations on graded lab reports, the poster session, and the final paper; and evaluations indicated that students had achieved the outlined goals. Students indicated on the evaluations that the research project increased their interest in research and greatly improved understanding of the course material. Finally, several students in the course intend to submit the findings of the research project to an undergraduate research journal.
Assessing Student Learning
Authors: Sundberg Marshall D.
Published: November 2002

Biology education research has now reached a level of maturity where the expectation is that researchers will assess the effectiveness of their innovation on student learning. This may include an examination of affective outcomes, such as student attitudes and beliefs, as well as student understanding of discipline-based content. A variety of tools are available to generate assessment data, each with certain advantages and disadvantages. They include not only quantitative measures, which lend themselves to familiar statistical analyses, but also qualitative techniques that can provide a rich understanding of complex outcomes. This article describes some of the most commonly used assessment techniques, their advantages and disadvantages, and typical ways such information is reported.
Changed lamellipodial extension, adhesion plaques and migration in epidermal keratinocytes containing constitutively expressed sense and antisense hyaluronan synthase 2 (Has2) genes
Authors: Rilla Kirsi , Lammi Mikko J. , Sironen Reijo , Törrönen Kari , Luukkonen Merja , Hascall Vincent C. , Midura Ronald J. , Hyttinen Mika , Pelkonen Jukka , Tammi Markku , Tammi Raija
Published: November 2002

Hyaluronan is a major component of the epidermal extracellular matrix, is actively synthesized by keratinocytes and shows fast matrix turnover in the stratified epithelium. We probed the importance of hyaluronan synthesis in keratinocytes by establishing cell lines carrying the exogenous hyaluronan synthase 2 (Has2) gene in sense and antisense orientations to increase and decrease their hyaluronan synthesis, respectively. Compared with cell lines transfected with the vector only, most clones containing the Has2 sense gene migrated faster in an in vitro wounding assay, whereas Has2 antisense cells migrated more slowly. Has2 antisense clones showed delayed entry into the S phase of cell cycle following plating, smaller lamellipodia and less spreading on the substratum. The decrease of hyaluronan on the undersurface of Has2 antisense cells was associated with an increased area of adhesion plaques containing vinculin. Exogenous hyaluronan added to the keratinocyte cultures had a minor stimulatory effect on migration after wounding but did not restore the reduced migratory ability of Has2 antisense cells. Hyaluronan decasaccharides that displace receptor bound hyaluronan in keratinocytes, and Streptomyces hyaluronidase sufficient to remove most cell surface hyaluronan had little effect on cell migration. The results suggest that the dynamic synthesis of hyaluronan directed by Has2, rather than the abundance of pericellular hyaluronan, controls keratinocyte migration, a cell function vital for the repair of squamous epithelia following wounding.
Parameter selection by an artificial neural network for a laser bending process
Authors: Casalino G , Ludovico A D
Published: November 2002

Based on thermally induced plastic deformations produced by laser irradiation, metal sheet laser bending can be a valid alternative to dies for rapid prototyping and manufacturing. Some numerical models have been built in order to improve the understanding and prediction of mechanisms. Drawbacks entailed with those models have been found. Finite element model simulation has proved to be time and CPU (central processing unit) memory consuming. The analytical models have been cumbersome and unsatisfactory. Nowadays, it is possible to build a neural network model for process modelling directly from data collected during the experiments.

In this paper a feed-forward neural network with a back-propagation learning function has been designed and its performances have been evaluated for metal sheet laser bending. This technique has proved to be effective and efficient, providing the process parameters that are necessary to achieve a desired bending angle.
An implementation of the business process modelling approach in the automotive industry
Authors: Monfared R P , West A A , Harrison R , Weston R H
Published: November 2002

The development and application of a business process modelling approach to comprehend, formalize, simulate and assess a particular domain within the automotive industry are described in this paper. Within an ongoing project carried out by Loughborough University, the design and implementation of a new generation of component-based machine control systems are being investigated. As part of this project, impacts of business and technical aspects of the new control systems on existing practices are also being examined using enterprise modelling methods and tools. The modelling has been applied to the production and assembly of a machine for a new engine project in the automotive industry.

The modelling approach has been based on the CIMOSA modelling architecture and complementary simulation and analysis tools, mainly ithink™ and Excel. The lessons learned from the implementation of the modelling approach and the assessment of the component-based machine control systems are also discussed in this paper. The criteria of this assessment were considered primarily as cost and time, although other factors that ultimately impact on the business processes are also discussed.
Discussion and analysis of stochastic feedback control adjustment
Authors: Venkatesan G
Published: November 2002

Process control techniques from engineering and statistical process control overlap at the interface of the two process control methodologies. In recent years, process control practitioners have focused their attention on statistical process monitoring and feedback control adjustment. It is quite common to encounter problems that are related to feedback (closed-loop) stability, controller limitations and dead-time compensation in order to obtain minimum variance (mean square error) at the output. A stochastic feedback control algorithm for input adjustment can be derived by use of techniques from the two process control methodologies. This paper briefly reviews statistical feedback control adjustment and describes a method to model stochastic feedback control adjustment in order to control the quality of products at the output of a continuous process. The method takes into consideration situations under which the product quality mean is on target/set point and situations where it is not on target by assigning suitable probabilities for the respective situations. A test of significance is conducted for such situations when a feedback control adjustment is required to bring the product quality mean on target and a suitable probability model is developed for such a situation.
Development of a PC-based computer numerical control drilling machine
Authors: Onwubolu G C , Aborhey S , Singh R , Reddy H , Prasad M , Kumar S , Singh S
Published: November 2002

In the research reported in this article, the personal computer (PC) is used as a separate, front-end interface for a customized machine control unit, which controls a drilling machine through actuation devices. Both the customized machine control unit and the drilling machine were built in-house. The PC-based computer numerical control drilling machine comprises several integrated technologies, ranging from a neuro-TSP (travelling salesman problem)-based optimizer for finding the best sequence of points to be drilled, a customized machine control unit and enhanced parallel port for communication to the drilling machine. Work is continuing to carry out experimental tests on the part produced by the machine and to compare the quality of such parts with those produced by similar machines.
A comprehensive engineering model for the design, manufacture and assembly of helical carpenter shapers
Authors: Chen W-F , Lai H-Y
Published: November 2002

Currently, straight cutting-edge carpenter shapers are widely used in the production process. The manner of contact between this traditional type of shaper and the workpiece is a piecewise continuous curve. One drawback of shapers of this type is that the noise generated during the cutting process tends to be very loud. In order to overcome this problem, the current paper takes the thickness of the cutter into account and employs the concept of equidistant lines and surfaces to develop a new carpenter shaper that comprises a helical cutting edge on a cylindrical shank surface. The geometric shape of the blade surface that is mounted in the groove of the cutter shank is first derived. The contact curve of the proposed carpenter shaper with the workpiece is shown to be continuous. In order to establish a geometric model that facilitates the simple production of a carpenter helical shaping cutter, this paper presents a new design approach, which constructs an equidistant and equivalent involute helical surface model and a corresponding planar unwinding torus model. The carpenter shaper thus obtained is proven to be successful in reducing the noise levels of the cutting process. The contact style of the shaper also offers the additional advantages of higher cutting efficiency, lower energy consumption and longer tool-life. A numerical example is presented to illustrate the effectiveness of the proposed modelling approach. The results indicate that the proposed carpenter helical shaping (CHS) cutter model is accurate, efficient and comprehensive. The model is sufficiently accurate that it can be used as a guideline for the design, manufacture and assembly of robust, reliable and silent wooden shapers.
Evaluation policies and automotive recovery options according to the European Union Directive on end-of-life vehicles (ELV)
Authors: Johnson M R , Wang M H
Published: November 2002

The European Union (EU) Directive on end-of-life vehicles (ELVs) is a newly ratified legislative policy that will change the management of ELVs in Europe by forcing auto manufacturers worldwide to take financial responsibility for the proper environmental handling of their vehicles at the product's end of life (EOL). Essentially, the new policy encompasses extended producer responsibility (EPR) by requiring hazardous materials to be removed from the vehicle and specific recovery targets (focusing on reuse and recycling) to be met. This paper presents the application of an analysis tool that uses demanufacturing optimization on a dismantled vehicle to evaluate the economics and material destinations within the imposed requirements of the new legislation. The results of the current study provide insight into the future problems and opportunities that will be brought forth by the new Directive.
Effects of the oil and liquid fuel film on hydrocarbon emissions in spark ignition engines
Authors: Yu S , Min K
Published: November 2002

A model was developed to assess the absorption and desorption of fuel in oil film and in the binary diffusion of oil and fuel films. This was investigated with a parametric study according to engine speed, load and oil film temperature. The results show that Henry's constant, which is related to solubility, is the most dominant parameter in the absorption/desorption mechanism of fuel into the oil film. Under warm-up conditions, engine speed had little influence on the amount of fuel absorbed/desorbed, but when the oil film temperature was low, the quantity of fuel absorbed/desorbed decreased with increasing engine speed. Liquid fuel on the oil film and piston head caused higher hydrocarbon (HC) emissions, and under base conditions (a simulated cold engine), the amount of fuel vaporized from fuel film and desorbed from wetted oil film was 24.5 per cent of the stoichiometric fuel mass. The effect of oil film with liquid fuel was 5.3 times larger than that of oil film without liquid fuel. The amount of fuel that escaped from the piston crevice was 1.3 times larger than that of fuel in the oil film. However, the fuel trapped in the oil film desorbed into the combustion chamber more slowly than the fuel that escaped from the piston crevices under cold engine conditions.
Numerical study of a Sahelian synoptic weather system: Initiation and mature stages of convection and its interactions with the large‐scale dynamics
Authors: Diongue A. , Lafore J.‐P. , Redelsperger J.‐L. , Roca R.
Published: November 2002

A 24 h multi‐scale simulation of the life cycle of a Sahelian squall line is presented. The initial and coupling fields have been taken from the European Centre for Medium‐Range Weather Forecasts re‐analysis (ERA‐15) after humidity corrections to avoid spurious absolute and conditional convective instabilities. Comparisons of model‐synthetic and Meteosat infra‐red radiances indicate that the simulated scenario of convection development and structure are realistic, though differences are found concerning the size of the squall line with a delay of 2–3 h. The simulated arc‐shaped structure and surface signature fit well with radar and ground station observations, respectively.

The mature stage of the simulated squall line presents a cross‐line structure similar to conceptual models. An intense rear‐to‐front flow is generated below the trailing stratiform part. An acceleration of the African easterly jet (AEJ) is simulated behind the system, occurring across its full width. This leads to the generation of a dipole of counter‐rotating vortices. The resulting potential‐vorticity signature leads to local reinforcement of the barotropic instability on the north flank of the AEJ.

This simulation is used to analyse the impact of the convection at synoptic‐scales and to compare it with ERA‐15. It suggests that the convection contributes to reinforce the monsoon at least up to 500 km. The monsoon inflow moves eastward and westward with time‐scales shorter and longer than 24 h, respectively. The tropical easterly jet intensifies to the south‐west of the convection area up to 700 km away. The AEJ is strongly intensified ahead of the trough where active convection occurs. Organized convection developing in the vicinity of the AEJ core induces weakening of the AEJ ahead of the squall line and strengthening behind it. A common result in the simulation and in ERA‐15 is that the AEJ core moves westward faster due to the convective activity. Copyright © 2002 Royal Meteorological Society
Improvement of surface flux parametrizations with a turbulence‐related length
Authors: Yang K. , Koike T. , Fujii H. , Tamagawa K. , Hirose N.
Published: November 2002

In surface flux parametrizations, aerodynamic roughness length zm0, and thermal roughness length zh0, are used to account for different resistances for momentum transfer and heat transfer. This paper introduces a turbulence‐related length hT and parametrizes the quantity kA−1=ln(hT/zh0) in order to estimate zh0. Based on data at three sites on the Tibetan Plateau, a general formula for kA−1 is obtained for the surfaces covered by bare soil or partially covered by very short vegetation. A surface flux parametrization with this formula provides better estimates of heat flux than either profile flux parametrization or surface flux parametrization with kB−1 (i.e. ln(zm0/zh0)). Therefore, the use of a reasonable length to scale zh0 can contribute to the improvement of surface flux parametrizations. Copyright © 2002 Royal Meteorological Society
In vitro toxicity of several dithiocarbamates and structure–activity relationships
Authors: Segovia N. , Crovetto G. , Lardelli P. , Espigares M.
Published: November 2002

Dithiocarbamates (DTCs) are chemicals featuring a great chelating capacity. The toxicological study of DTCs is very important in view of their relatively simple synthesis and wide array of sanitary and industrial applications. In this study, the toxicity of some of the more recently synthesized DTCs is determined using an extremely simple bioassay, described in previous studies, based on the inhibition of growth of Escherichia coli (IGEC). The lowest‐observed‐effect concentration (LOEC), the median effective concentration (EC50) and no‐observed‐effect concentration (NOEC) of the following sodium dithiocarbamates was determined: N‐benzyl‐N‐methyldithiocarbamate·2H2O, N‐benzyl‐N‐isopropyldithiocarbamate·3H2O, N‐benzyl‐N‐ethyldithiocarbamate·2H2O, N‐butyl‐N‐methyldithiocarbamate·2H2O, N,N‐dibenzyldithiocarbamate·2H2O and N‐benzyl‐2‐phenethyldithiocarbamate·4H2O. Our results showed N,N‐dibenzyl‐DTC to be the least toxic of the tested substances, with an EC50 value of 1269.9 µg ml−1, whereas N‐butyl‐N‐methyl‐DTC and N‐benzyl‐N‐methyl‐DTC, with respective EC50 values of 14.9 µg ml−1 and 23.5 µg ml−1, were the most toxic. Regression analysis showed, through exponential models, that the degree of toxicity of this group of substances correlated with the molecular weight of the compound, the molecular weight of the smallest chemical radical linked to the dithiocarbamate group and the number of benzene rings present in the molecule. The consideration of these models allows us to establish that in general terms the toxicity of DTCs decreases exponentially with a greater molecular weight and the number of benzene rings. Copyright © 2002 John Wiley & Sons, Ltd.