Relative scarcity of asthma and atopy among rural adolescents raised on a farm

We determined the prevalence of markers of atopy and asthma among 1, 199 rural secondary school students ages 12 to 19 yr. Subjects identified as having been raised on a farm and half as many subjects without regular exposure to a farming environment from the same school class completed a respiratory symptom questionnaire and underwent allergy skin tests and a methacholine bronchoprovocation test. Current wheeze, airways hyperresponsiveness (AHR), and skin test positivity to inhaled allergens were all significantly less common among adolescents raised on the farm and these differences were especially pronounced in girls. After adjusting for gender and current smoking, the odds ratios for being raised on a farm were: 0. 70 (95% CI 0.52 to 0.95) for current wheeze; 0.59 (95% CI 0.37 to 0. 95) for asthma, defined as the concomitant occurrence of wheeze and AHR; and 0.58 (95% CI 0.46 to 0.75) for atopy defined as a positive reaction to any one of 24 common inhaled allergens. These associations were also not significantly altered by adjusting for the difference in the number of siblings.

Prostaglandin H synthase 2 expression in airway cells from patients with asthma and chronic obstructive pulmonary disease

Products of the prostaglandin H synthase (PGHS) metabolic pathway are thought to play a role in the pathogenesis of asthma. We determined the level of expression of the constitutive (PGHS-1) and inducible (PGHS-2) isoforms of the enzyme in induced sputum and bronchial biopsies of patients with asthma, patients with chronic obstructive pulmonary disease (COPD), and unaffected control subjects by immunocyto- and immunohistochemistry. Immunoreactivity for PGHS-2 was significantly greater in the induced sputum of patients with asthma and patients with COPD compared with unaffected control subjects. The level of PGHS-2 was greater in asthma than in COPD. Immunoreactivity for PGHS-1 increased in cells in the induced sputum of patients with asthma and patients with COPD compared with that of unaffected control subjects. Immunostained cells included macrophages, eosinophils, and neutrophils. Greater PGHS-2 immunoreactivity was seen in the submucosal inflammatory infiltrate and in the airway epithelium of patients with asthma compared with unaffected control subjects. In summary, we demonstrate an induction of PGHS-2 in asthma, suggesting increased formation of prostanoids, which may contribute to the inflammatory process.

Mammalian Trithorax and polycomb-group homologues are antagonistic regulators of homeotic development

Control of cell identity during development is specified in large part by the unique expression patterns of multiple homeobox-containing (Hox) genes in specific segments of an embryo. Trithorax and Polycomb-group (Trx-G and Pc-G) proteins in Drosophila maintain Hox expression or repression, respectively. Mixed lineage leukemia (MLL) is frequently involved in chromosomal translocations associated with acute leukemia and is the one established mammalian homologue of Trx. Bmi-1 was first identified as a collaborator in c-myc-induced murine lymphomagenesis and is homologous to the Drosophila Pc-G member Posterior sex combs. Here, we note the axial-skeletal transformations and altered Hox expression patterns of Mll-deficient and Bmi-1-deficient mice were normalized when both Mll and Bmi-1 were deleted, demonstrating their antagonistic role in determining segmental identity. Embryonic fibroblasts from Mll-deficient compared with Bmi-1-deficient mice demonstrate reciprocal regulation of Hox genes as well as an integrated Hoxc8-lacZ reporter construct. Reexpression of MLL was able to overcome repression, rescuing expression of Hoxc8-lacZ in Mll-deficient cells. Consistent with this, MLL and BMI-I display discrete subnuclear colocalization. Although Drosophila Pc-G and Trx-G members have been shown to maintain a previously established transcriptional pattern, we demonstrate that MLL can also dynamically regulate a target Hox gene.

Canadian Asthma Consensus Report, 1999. Canadian Asthma Consensus Group

OBJECTIVES

To provide physicians with current guidelines for the diagnosis and optimal management of asthma in children and adults, including pregnant women and the elderly, in office, emergency department, hospital and clinic settings.

OPTIONS

The consensus group considered the roles of education, avoidance of provocative environmental and other factors, diverse pharmacotherapies, delivery devices and emergency and in-hospital management of asthma.

OUTCOMES

Provision of the best control of asthma by confirmation of the diagnosis using objective measures, rapid achievement and maintenance of control and regular follow-up.

EVIDENCE

The key diagnostic and therapeutic recommendations are based on the 1995 Canadian guidelines and a critical review of the literature by small groups before a full meeting of the consensus group. Recommendations are graded according to 5 levels of evidence. Differences of opinion were resolved by consensus following discussion.

VALUES

Respirologists, immunoallergists, pediatricians and emergency and family physicians gave prime consideration to the achievement and maintenance of optimal control of asthma through avoidance of environmental inciters, education of patients and the lowest effective regime of pharmacotherapy to reduce morbidity and mortality.

BENEFITS, HARMS AND COSTS

Adherence to the guidelines should be accompanied by significant reduction in patients' symptoms, reduced morbidity and mortality, fewer emergency and hospital admissions, fewer adverse side-effects from medications, better quality of life for patients and reduced costs.

RECOMMENDATIONS

Recommendations are included in each section of the report. In summary, after a diagnosis of asthma is made based on clinical evaluation, including demonstration of variable airflow obstruction, and contributing factors are identified, a treatment plan is established to obtain and maintain optimal asthma control. The main components of treatment are patient education, environmental control, pharmacotherapy tailored to the individual and regular follow-up.

VALIDATION

The recommendations were distributed to the members of the Canadian Thoracic Society Asthma and Standards Committees, as well as members of the board of the Canadian Thoracic Society. In addition, collaborating groups representing the Canadian Association of Emergency Physicians, the Canadian College of Family Physicians, the Canadian Paediatric Society and the Canadian Society of Allergy and Immunology were asked to validate the recommendations. The recommendations were discussed at regional meetings throughout Canada. They were also compared with the recommendations of other similar groups in other countries. DISSEMINATION AND IMPLEMENTATION: An implementation committee has established a strategy for disseminating these guidelines to physicians, other health professionals and patients and for developing tools and means that will help integrate the recommendations into current asthma care. The plan is outlined in this report.

Case-control study of lung cancer among sugar cane farmers in India

OBJECTIVES

To investigate the risk of lung cancer among sugar cane farmers and sugar mill workers.

METHODS

A case-control study was conducted based in six hospitals in the predominantly sugar cane farming districts of the province of Maharashtra in India. Newly diagnosed, histologically confirmed cases were identified from these hospitals between May 1996 and April 1998. Other cancers were chosen as controls and matched to cases by age, sex, district of residence, and timing of diagnosis.

RESULTS

Adjusting for confounders, an increased risk of lung cancer was found for workers ever employed on a sugar cane farm (odds ratio (OR) 1.92, 95% confidence interval (95% CI) 1.08 to 3.40). Increased risks were found for work involving preparation of the farm (OR 1.81, 95% CI 0.99 to 3.27) and burning of the farm after harvesting (OR 1.82, 95% CI 0.99 to 3.34). Non-significant increases in risks were found for harvesting the crop (OR 1.41, 95% CI 0.70 to 2.90) and processing the cane in the mills (OR 1.70, 95% CI 0.20 to 12.60).

CONCLUSIONS

Exposure to fibres of biogenic amorphous silica (BAS) formed from silica absorbed from the soil and deposited in the leaves of the sugar cane crop or crystalline silica formed as a result of conversion of BAS to cristobalite at high temperatures may account for the increased risks of lung cancer among sugar cane farmers.

Phenotype of IL-16-producing cells in bronchial mucosa: evidence for the human eosinophil and mast cell as cellular sources of IL-16 in asthma

BACKGROUND

We have previously shown increased expression of the CD4+ cell chemoattractant interleukin (IL)-16 in bronchial biopsies of atopic asthmatic subjects compared to normal controls. IL-16 immunoreactive cells were identified as both epithelial cells and non-epithelial inflammatory cells. The aim of this study was to characterize and compare the phenotype of non-epithelial inflammatory cells that express IL-16 immunoreactivity in bronchial biopsies from non-atopic normal controls and atopic asthmatic subjects.

METHODS

Sections from endobronchial biopsies obtained from non-atopic normal controls and atopic asthmatics were processed for double immunocytochemistry. IL-16 immunoreactivity was assessed using a polyclonal anti-IL-16 antibody and the avidin-biotin complex-diaminobenzidine method. The phenotype of IL-16 immunoreactive cells was assessed using anti-CD3, anti-MBP, anti-tryptase and anti-CD68 mAbs and the alkaline phosphatase complex-Fast Red method.

RESULTS

In normal subjects, the majority of IL-16 immunoreactive cells were CD3+ T cells (71.1+/-10.3%) and CD68+ macrophages (22.4+/-8.1%). IL-16 immunoreactivity coexpressed with tryptase+ mast cells in 4 of 7 normal subjects whereas IL-16 immunoreactivity coexpressed with MBP+ eosinophils in only 1 normal subject. In atopic asthmatic subjects, IL-16 immunoreactive cells were mainly CD3+ T cells (60.8+/-8.7%) and MPB+ eosinophils (16.8+/-8.2%). IL-16 immunoreactivity also coexpressed with tryptase+ mast cells (10.6+/-4.0%) in all asthmatic subjects. The number of IL-16 immunoreactive cells that coexpressed MBP was higher in asthmatic subjects compared to normal controls (p = 0.003).

CONCLUSION

Our data show that T cells are the major non-epithelial cellular source of IL-16 in normal and asthmatic airways. Eosinophils and mast cells comprised other potential cellular sources of IL-16 in asthmatic airways.

Review article: the role of inflammation in the pathogenesis of gastric cancer

Helicobacter pylori induces infiltration of the gastric mucosa by polymorphonuclear cells and macrophages, as well as T and B lymphocytes. Paradoxically, this robust immune/inflammatory response cannot clear the infection, and thus leaves the host prone to complications resulting from chronic inflammation. One adverse consequence of this inflammatory response may be gastric cancer, as inflammation has been implicated in the development of intestinal metaplasia and mutations in oncogenes that precede the development of gastric adenocarcinoma. The gastric inflammatory response is affected somewhat, by the strain of H. pylori that infects the host. Thus, the more severe clinical manifestation associated with some strains may be attributed to the higher grade of inflammation that they induce. Both H. pylori and cytokines induced during infection can stimulate the recruitment and activation of inflammatory cells including neutrophils and macrophages. When activated, these cells produce inflammatory mediators that include reactive oxygen species (ROS). These mediators impart an oxidative stress on the cells in the immediate vicinity, in this case, the gastric epithelium. Normally, oxidative stress is neutralized by natural antioxidants such as vitamin C, however, levels of this antioxidant in the gastric juice are decreased during infection. The increased levels of oxidants and decreased antioxidants create a stress that can change many processes in the gastric epithelium. For example, an accumulation of intracellular ROS regulates the expression of many genes and can induce DNA damage. Point mutations in the DNA that disrupt the expression and function of genes that inhibit cell growth (i.e. p53) are believed to contribute to the pathogenesis of gastric cancer. Several studies suggest that epithelial cell turnover is affected by the inflammatory response to H. pylori. This notion is supported by studies describing an increase in both epithelial cell proliferation, as well as cell death by apoptosis, in response to infection. Apoptosis is a regulated process of cell death that is triggered by H. pylori as well as various inflammatory mediators, including tumour necrosis factor and interferon-gamma. Activated T-cells also kill gastric epithelial cells directly. Moreover, the host response increases the expression of receptors for H. pylori and thus increases bacterial binding and the induction of apoptosis by the bacteria. There are several other immune/inflammatory responses that contribute to epithelial cell damage mucosa and the pathogenesis of gastric cancer. For example, gastric B cells produce autoreactive antibodies that bind to gastric epithelial cells. As a consequence of this antigen-antibody complex formation, complement becomes activated suggesting that some of the inflammation and epithelial cell damage is attributable to immune-complex formation. Epithelial cell death can then stimulate the proliferative response of epithelial cell precursors. In summary, the proposed model may explain how the gastric inflammatory response contributes to the pathogenesis of cancer. This model raises the possibility that it could be preferable to identify the patients at highest risk of developing gastric cancer and then apply an intervention that eliminates the infection and inflammatory response. Alternatively, clinical interventions should at least attenuate the oxidative stress that is directly attributed to inflammation. These mechanisms have to be examined in the paediatric population.

First treatment with inhaled corticosteroids and the prevention of admissions to hospital for asthma

BACKGROUND

Early treatment with inhaled corticosteroids appears to improve clinical symptoms in asthma. Whether a first treatment initiated in the year following the recognition of asthma can prevent major outcomes such as admission to hospital has yet to be studied.

METHODS

A case-control study nested within a cohort of 13,563 newly treated asthmatic subjects selected from the databases of Saskatchewan Health (1977-1993) was undertaken to investigate the effectiveness of a first treatment with inhaled corticosteroids in preventing admissions to hospital for asthma. Study subjects were aged between five and 44 years at cohort entry. First time users of inhaled corticosteroids were compared with first time users of theophylline for a maximum of 12 months of treatment. The two treatments under study were further classified into initial and subsequent therapy to minimize selection bias and confounding by indication. Odds ratios associated with hospital admissions for asthma were estimated using conditional logistic regression. Markers of asthma severity, as well as age and sex, were considered as potential confounders.

RESULTS

Three hundred and three patients admitted to hospital with asthma were identified and 2636 matched controls were selected. subjects initially treated with regular inhaled corticosteroids were 40% less likely to be admitted to hospital for asthma than regular users of theophylline (odds ratio 0.6; 95% CI 0.4 to 1.0). The odds ratio decreased to 0.2 (95% CI 0.1 to 0.5) when inhaled corticosteroids and theophylline were given subsequently.

CONCLUSION

The first regular treatment with inhaled corticosteroids initiated in the year following the recognition of asthma can reduce the risk of admission to hospital for asthma by up to 80% compared with regular treatment with theophylline. This is probably due, at least in part, to reducing the likelihood of a worsening in the severity of asthma.

Urinary excretion and pharmacokinetics of acrolein and its parent drug cyclophosphamide in bone marrow transplant patients

The urinary excretion and pharmacokinetics of acrolein (ACRO) and its parent drug cyclophosphamide (CP) were investigated in 16 randomly selected bone marrow transplant (BMT) recipients when CP was used for conditioning. Patients suffering from aplastic anemia (n = 3) received a 4-day course of CP at a dose of 50 mg/kg daily infused intravenously (i.v.) over 1 h. Patients with leukemia (n = 13) were given either a combination of busulphan followed by CP at a dose of 50 mg/kg infused i.v. over 1 h for 4 days, or CP at a dose of 60 mg/kg by i.v. infusion over 1 h daily for 2 days followed by total body irradiation. Serial plasma samples and urine were collected after the start of the first CP dose. CP was analyzed by capillary gas chromatography, whereas ACRO was measured in urine by liquid chromatography. The plasma concentration-time data for CP conformed to the two-compartment model and the mean and s.e.m. values of alpha, beta, Vss, total clearance, and renal clearance observed were 1.29 (0.31) h(-1), 0.17 (0.03) h(-1), 0.67 (0.13) l/kg, 0.14 (0.02) l/h x kg, and 0.0188 (0.0052) l/h x kg, respectively. The mean and s.e.m. values of fraction of CP excreted in the form of ACRO during this interval (fmu) and ratio of the 24-h urinary concentration of ACRO/creatinine (Cmu(n)) were 1.96 (0.35%) and 9.11 (2.19) microg of ACRO/mg of creatinine, respectively. Two patients developed hemorrhagic cystitis (HC). Each of these two patients excreted significantly (P < 0.01) more ACRO in the first and second 4-h urine collection periods. However, there was no significant difference in fmu or Cmu(n) of ACRO between either of these two patients and the rest. This suggests that the rate of appearance of ACRO in urine is more crucial for developing HC than the cumulative amount excreted.

Antihypertensive drugs and the risk of gastrointestinal bleeding

PURPOSE

Calcium channel blockers have been reported to increase the risk of gastrointestinal bleeding. We tested this hypothesis, and also assessed whether beta blockers decrease this risk.

SUBJECTS AND METHODS

A nested case-control design within a population-based cohort of all 34,074 new users of beta blockers, angiotensin-converting enzyme (ACE) inhibitors, or calcium channel blockers in Saskatchewan, from 1990 to 1993 and followed up to March 1995, was used. We identified all 311 subjects hospitalized because of gastrointestinal bleeding during this period, each of whom was matched to 10 randomly selected controls.

RESULTS

The rate of hospitalization for gastrointestinal bleeding was 3.0 per 1,000 per year. The adjusted rate ratio of gastrointestinal bleeding for current use of calcium channel blockers was 1.1 (95% confidence interval [CI] 0.8 to 1.4) and 0.66 (95% CI 0.44 to 0.98) for beta blockers compared with no current use of anti-hypertensive drugs. The adjusted rate ratio for ACE inhibitor use was 1.0 (95% CI 0.7 to 1.3) while that for diuretic use was 1.4 (95% CI 1.0 to 2.0).

CONCLUSIONS

The use of calcium channel blockers does not appear to increase the risk of gastrointestinal bleeding in the first five years of treatment, while beta blockers may prevent this adverse event. The unexpected elevated risk associated with the use of diuretics needs to be investigated further.

Increased formation of the potent oxidant peroxynitrite in the airways of asthmatic patients is associated with induction of nitric oxide synthase: effect of inhaled glucocorticoid

Peroxynitrite is a potent oxidant formed by the rapid reaction of the free radicals nitric oxide (NO) and superoxide. It causes airway hyperresponsiveness and airway epithelial damage, enhances inflammatory cell recruitment, and inhibits pulmonary surfactant. Asthma is characterized by increased airway hyperresponsiveness, airway epithelial shedding, and inflammation. We examined the production of peroxynitrite and the expression of inducible nitric oxide synthase (iNOS) in airways of asthmatic patients compared to normal control subjects. We also performed a double-blind, crossover randomized-order, placebo-controlled study on 10 asthmatic patients to study the effects of inhaled glucocorticoid treatment (Budesonide) on the formation of peroxynitrite and NO. Fiberoptic bronchial biopsies were examined by immunohistochemistry with antiserum to nitrotyrosine, a marker of protein nitration by peroxynitrite. We also examined the expression of iNOS by immunohistochemistry and in situ hybridization, and measured exhaled NO by chemiluminescence. We correlated the airway production of peroxynitrite with pulmonary functions and airway responsiveness. In airway passages of control subjects, there was weak or no nitrotyrosine immunoreactivity. In contrast, there was strong immunoreactivity for nitrotyrosine in the airway epithelium and inflammatory cells in the airways of persons with asthma. Budesonide treatment resulted in a significant reduction in nitrotyrosine immunoreactivity. Expression of iNOS was evident in the airway pithelium of controls and asthmatic patients, but was significantly more abundant in asthmatic patients. The presence of nitrotyrosine in the airway epithelium (r=-0.841, P<0.0001; r=-0.771, P=0.0004) and inflammatory cells (r=-0.727, P=0014; r=-0.681, P=0.004) correlated inversely with methacholine PC20 and forced expiratory volume in 1 s, respectively. Asthma is associated with increased peroxynitrite formation in the airways, which is reduced after Budesonide treatment. The potent oxidant peroxynitrite may contribute to airway obstruction and hyperresponsiveness and epithelial damage in asthma.

Inhaled corticosteroids and the prevention of readmission to hospital for asthma

Despite the proven efficacy of inhaled corticosteroids in reducing airway inflammation and their increasing use for the treatment of asthma since the mid 1980s, hospitalization for asthma has been increasing in frequency in several countries. Only few studies, reporting contradictory results, have investigated the role of inhaled corticosteroids in the prevention of hospitalizations for asthma. Using a cohort of 2,059 hospitalized asthmatic patients between 5 and 54 yr of age, we estimated the effectiveness of inhaled corticosteroids in preventing a readmission to hospital for asthma as a function of the duration of therapy. The cohort was selected from the databases of Saskatchewan Health from 1977 to 1993. The rate ratio (RR) of a readmission for asthma varied with duration of regular therapy with inhaled corticosteroids. During the first 15 d of regular therapy, users of inhaled corticosteroids were as likely as nonusers of these medications to be readmitted for asthma with a RR of 1.2 (95% CI: 0.8-1.8). Subjects treated regularly with inhaled corticosteroids for at least 16 d and as long as 6 mo were 40% less likely to be readmitted for asthma (RR = 0.6; 95% CI: 0.4-0.9), while after 6 mo of regular treatment the protective effect disappeared (RR = 1.3; 95% CI: 0.7-2.4). We conclude that regular therapy with inhaled corticosteroids can substantially reduce the risk of a readmission for asthma after only 15 d of use. Confounding by severity appears as the most likely explanation for the disappearance of the beneficial effect after 6 mo of regular therapy.

The role of domestic factors and day-care attendance on lung function of primary school children

The results of studies examining the relationship of domestic factors to lung function are contradictory. We therefore examined the independent effects of maternal smoking during pregnancy, exposure to environmental tobacco smoke (ETS), the presence of a cat, type of heating and cooking used in the home and day-care attendance on lung function after controlling for socioeconomic status (SES). Nine hundred and eighty-nine children from 18 Montreal schools were studied between April 1990 and November 1992. Information on the child's health and exposure to domestic factors was collected by questionnaire. Spirometry was performed at school. The data were analysed by multiple linear regression with percent predicted FEV1, FVC, and FEV1/FVC as dependent variables. In the overall sample (both sexes combined), cat in the home (regression coefficient, beta = -1.15, 95% confidence interval, CI: -2.26-(-)0.05) and electric baseboard units (beta = -1.26, 95% CI: -2.39-(-)0.13) were independently associated with a lower FEV1/FVC, while day-care attendance (beta = -2.05, 95% CI: -3.71-(-)0.40) significantly reduced FEV1. Household ETS was significantly associated with increasing level of FVC (beta = 2.86, 95% CI: +0.55 to +5.17). In boys but not girls, household ETS (beta = -2.13, 95% CI: -4.07-(-)0.19) and the presence of a cat (beta = -2.19, 95% CI: -3.94-(-)0.45) were associated with lower FEV1/FVC. By contrast, day-care attendance was associated with lower FEV1 (beta = -2.92, 95% CI: -5.27-(-)0.56) and FEV1/FVC (beta = -1.53, 95% CI: -2.73-(-)0.33) in girls only. In conclusion, the results provide evidence that domestic factors and day-care attendance primarily affected airway caliber and gender differences were apparent in the effects of these factors.

Cataracts after total body irradiation and bone marrow transplantation in patients with acute leukemia in complete remission: a study of the European Group for Blood and Marrow Transplantation

PURPOSE

Advances in bone marrow transplantation (BMT) have consistently improved long-term survival. Therefore, evaluation of late complications such as cataracts is of paramount importance.

METHODS AND MATERIALS

We analyzed data of 2149 patients from the EBMT registry. A cohort of 1063 patients were evaluable for survival and ophthalmologic status after transplant for acute leukemia (AL) in first or second complete remission. Conditioning therapy included either single-dose total body irradiation (STBI) or fractionated TBI (FTBI) grouped in different dose rates (low: LDR < or = 0.04 Gy/min; high: HDR > 0.04 Gy/min).

RESULTS

The overall 10-year estimated cataract incidence (ECI) was 50%. It was 60% in the STBI group, 43% in the FTBI group < or = 6 fractions, and 7% in the FTBI group > 6 fractions (p < 10(-4)). It was significantly lower (30%) in the LDR than in the HDR groups (59%;p < 10(-4)). Patients receiving heparin for veno-occlusive disease prophylaxis had fewer cataracts than those who did not (10-year ECI: 33% vs. 53%, respectively;p = 0.04). The 10-year ECI was 65% in the allogeneic vs. 46% in the autologous BMT patients (p = 0.0018). Factors independently associated with an increased risk of cataract were an older age (> 23 years), higher dose rate (> 0.04 Gy/min), allogeneic BMT, and steroid administration (> 100 days). The use of FTBI was associated with a decreased risk of cataract. Heparin administration was a protective factor in patients receiving STBI. In terms of cataract surgery, the unfavorable factors for requiring surgery were: age > 23 yr, STBI, dose rate > 0.04 Gy/min, chronic graft-vs.-host disease (cGvHD), and absence of heparin administration. Among the patients who required cataract surgery (111 out of 257), secondary posterior capsular opacification was observed in 15.7%.

CONCLUSION

High dose rate and STBI are the main risk factors for cataract development and the need for surgery, and the administration of heparin has a protective role in cataractogenesis.

W2H: WWW interface to the GCG sequence analysis package

MOTIVATION

The user-friendly, graphical X-windows interface (WPI) to the GCG sequence analysis package can often not be used due to the lack of an X-server on PC or Macintosh computers. Because Web browsers like Netscape are much more common on those platforms, we decided to develop W2H, a WWW interface to the GCG Sequence Analysis Software Package with nearly the same functionality as the X-windows interface WPI.

RESULTS

The new WWW interface (W2H) to the GCG Sequence Analysis Software Package (Wisconsin Package) supports modern Web technologies, like client-pull method, or embedded scripting language, and provides a reasonable platform independence. The interface is quite comprehensive with advanced features like sequence selector, search set builder, enzyme chooser, access to sequence databases, uploading client files to the GCG server or displaying and manipulating graphical outputs in addition to GCG analysis programs. W2H also manages secure access to both GCG server and user data. For special environments, like workshops, conferences and company intranets, there is a special mode (Intranet mode) with less security constraints. The behaviour of W2H is mostly controlled by meta-data files describing the applications and giving a base for dynamic creation of HTML documents. This paper presents mainly the development approaches used, and architectural design aspects of W2H.

AVAILABILITY

W2H is available by ftp://ftp.ebi.ac. uk/pub/software/unix/w2h or ftp://genome.dkfz-heidelberg.de/pub/w2h

CONTACT

m.senger@ebi.ac.uk

Inhaled drug delivery: a practical guide to prescribing inhaler devices

Direct delivery of medication to the target organ results in a high ratio of local to systemic bioavailability and has made aerosol delivery of respiratory medication the route of choice for the treatment of obstructive lung diseases. The most commonly prescribed device is the pressurized metered dose inhaler (pMDI); its major drawback is the requirement that inspiration and actuation of the device be well coordinated. Other requirements for effective drug delivery include an optimal inspiratory flow, a full inspiration from functional residual capacity and a breath hold of at least 6 s. Available pMDIs are to be gradually phased out due to their use of atmospheric ozone-depleting chlorofluorocarbons (CFCs) as propellants. Newer pMDI devices using non-CFC propellants are available; preliminary experience suggests these devices greatly increase systemic bioavailability of inhaled corticosteroids. The newer multidose dry powder inhalation devices (DPIs) are breath actuated, thus facilitating coordination with inspiration, and contain fewer ingredients. Furthermore, drug delivery is adequate even at low inspired flows, making their use appropriate in almost all situations. Equivalence of dosing among different devices for inhaled corticosteroids will remain imprecise, requiring the physician to adjust the dose of medication to the lowest dose that provides adequate control of asthma. Asthma education will be needed to instruct patients on the effective use of the numerous inhalation devices available.

Bayesian estimation of asthma prevalence, and comparison of exercise and questionnaire diagnostics in the absence of a gold standard

PURPOSE

To estimate the sensitivities, specificities, and predictive values of exercise challenge and questionnaire, when these tests are used to diagnose asthma in children.

METHODS

Participants were children, predominantly aged 6 to 12 years, selected from three primary school grades among 18 different schools in Montreal. Of 1111 participants, 989 successfully completed a six-minute free running test at school and returned a respiratory questionnaire. A total of 952 children had complete information that could be used for analysis. A history of wheezing in the past year in conjunction with a past diagnosis of asthma defined current asthma by questionnaire. Exercise responsiveness was defined as a > or = 10% fall in FEV1 after a six-minute free run. As there is no perfectly accurate diagnostic test for asthma, we analyzed the data using a previously published Bayesian method that allows for the estimation of test properties when no gold standard test is available.

RESULTS

Current asthma by questionnaire was found to have significantly higher specificity (94.9%, 95% credible interval (CI): 93.2-96.5 versus 82.6%, 95% CI: 79.9-85.1) and positive predictive value (53.8%, 95% CI: 41.0-66.7 versus 19.2%, 95% CI: 12.3-27.8) in comparison to exercise challenge. While there was no statistically significant difference between the two tests with respect to sensitivity and negative predictive values, the estimates were higher for current asthma (64.4%, 95% CI: 50.9-76.6 and 96.7%, 95% CI: 94.6-98.1, respectively) in comparison to exercise challenge (51.3%, 95% CI: 37.8-64.5 and 95.4%, 95% CI: 93.2-97.1, respectively). Agreement between the two diagnostic methods was poor and the combined use of the two tests did not significantly improve the likelihood of correctly identifying children with asthma.

CONCLUSIONS

Our findings support the view that exercise testing adds little to a well designed questionnaire in identifying subjects with asthma in community based studies.

Effects of an immunostimulating agent on acute exacerbations and hospitalizations in patients with chronic obstructive pulmonary disease. The PARI-IS Study Steering Committee and Research Group. Prevention of Acute Respiratory Infection by an Immunostimulant

The PARI-IS Study is a double-blind placebo-controlled randomized clinical trial to study the effect of an immunostimulating agent to prevent acute respiratory exacerbation in patients with COPD. Three hundred eighty-one ambulatory patients (190 placebo and 191 immunostimulant) were followed at home for 6 mo by experienced research nurses. The risk of having at least one episode of acute exacerbation (primary outcome) was similar in the two groups (p = 0.872). In contrast, the total number of days of hospitalization for a respiratory problem was 55% less in the group treated with OM-85 BV (287 d) than in the group treated with placebo (642 d). Patients treated with OM-85 BV spent an average of 1.5 d in hospital compared with 3.4 d for patients treated with placebo (p = 0.037). The risk of being hospitalized for a respiratory problem was 30% lower in the treated group (16.2%) than in the placebo group (23.2%); p = 0.089. Eight deaths were observed: two in patients treated with OM-85 BV and six in patients treated with placebo (p = 0.153). During the course of the study dyspnea improved slightly in patients treated with OM-85 BV, whereas it deteriorated slightly in patients receiving placebo (p = 0.028). These results suggest that this immunostimulating agent may be beneficial for patients with COPD by reducing the likelihood of severe respiratory events leading to hospitalization.

Airway function among Inuit primary school children in far northern Quebec

The study of the prevalence and determinants of asthma and allergy in different populations may provide clues to their etiology. We describe airway function and its determinants among Inuit schoolchildren living in far Northern Quebec. We assessed the presence of airways hyperresponsiveness (AHR), defined as a 15% drop in FEV1 with exercise, airflow obstruction, as judged by a reduced FEV1/FVC, and atopy, as evidenced by skin test positivity to inhaled aeroallergens, among 509 Inuit aged mostly from 6 to 13 yr. Smoking by the children (31.9%) and their parents was common, including maternal smoking during pregnancy (79.5%). Atopy was found in only 5.3% of children. Apart from age, there were no significant associations between AHR and any of the determinants examined. Airflow obstruction was present among 7.7% of children and occurred most commonly among children with higher levels of salivary cotinine and in those with four or more lower respiratory illnesses in the first 2 yr of life. Asthma and atopy were uncommon in this population whereas evidence of chronic airflow obstruction was frequently found. Measures to reduce the spread of respiratory infection and prevention of smoking are likely to be of most benefit in improving respiratory health in these isolated communities.